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4326 4330.output

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4326 4330.output

  1. 1. * GB784733 (A) Description: GB784733 (A) ? 1957-10-16 Improvements relating to electrical apparatus for measuring torsional forces or oscillation in rotating bodies Description of GB784733 (A) COMPLETE SPECIFICATION Improvements relating to electrical Apparatus for Measuring Torsional Forces or Oscillation in Rotating Bodies We, DAIMLER-BENZ ARTIENGESELLSCHAFTN of Stuttgart-Unterturkheim, Germany, a Com- pany organised under the Laws of Germany do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the fol lowing statement: This invention concerns improvements relating to electrical instruments for measur ing torsional forces or oscillations in rotating bodies, for example shafts or other parts of machines, of the kind utilising carrier-fre quency modulation. In such apparatus, for instance as described in the Specifications of our Patents Nos. 762,668 and 773,582 the forces or oscillations are measured by means of electrical variations produced by the rela tive movement of measuring elements such as coils and magnetic cores or parts of a con denser which are secured to different parts of the rotating body or to a part of the said body and to an inertia mass respectively. The elec trical variation is then utilised to cause modu lation of a carrier-frequency current in a bridge whose output is amplified and passed to a demodulator connected
  2. 2. to an indicating or recording device. It is accordingly neces sary to establish electrical connection between parts of the circuit which rotate with the rotate ing body on the one hand and parts of the circuit which do not rotate on the other hand. Heretofore it has been proposed to estab lish this connection by means of slip rings. Such slip rings, however, intro duce relatively high contact resistances whose influence is the more detrimental to the measurement the smaller the aforesaid electrical variations. Furthermore changes in the resistance at the slip rings due to wear of the carbon brushes or to jumping of the said brushes at high speeds of revolu tion have a particularly disadvantageous effect when carrier-frequency modulation is utilised as aforesaid. High contact pressure for the brushes will remedy the disadvantage to some extent, but aggravates the brush wear. The detrimental effect of the slip rings can be reduced by arranging for the bridge, not merely the measuring elements, to rotate with the rotating body. However, the presence of the slip rings is still disadvantageous and their operation imperfect, especially at high revolution. speeds. The present invention seeks to obivate the above-described deficiencies by eliminating the slip rings. According to the invention, in an electrical instrument for measuring torsional forces or oscillations in a rotating body, measurement is effected by means of electrical variations produced in elements rotating with the said body, which variations are used to modulate a carrier-frequency current in a bridge connected through an amplifier and demodulatoi: to an indicating or recording device, the bridge being also arranged to rotate with the said body and being coupled inductively, without the use of slip rings, both to a generator supplying the carrier frequency current and to the amplifier. Thus the coupling may be effected by a pair of coils of which one is connected electrically to the generator and the other to input terminals of the bridge and a pair of coils of which one is connected electrically to the amplifier and the other to output terminals of the bridge, the second-named coils of each pair being connected to the rotating body so as to rotate therewith while the first-named coils are stationary, and the pairs of coils being disposed side by side. Preferably, the coils connected to the generator and to the amplifier
  3. 3. are disposed concentrically around the outsides of the other coils of the respective pairs. It will be appreciated that although there is relative rotation between the coils of the respective pairs, this does not affect the paths for the magnetic fluxes linked with them. Each of the coils may be disposed in an annular yoke of U-shaped cross section and preferably made of laminated soft iron, the open sides of the U-sections of the yokes of inner and outer coils of respective pairs facing each other. Advantageously, the limbs of the U-sections of the yokes facing each other are of different widths, so that slight relative axial displacement can take place between the inner coils and the outer coils without the narrower limbs passing outside the limits of the widths of the wider limbs. Consequently such axial displacement, due say to play in bearings between the rotating and stationary parts of the instrument, can take place without materially affecting the paths, between the said limbs, fot the magnetic fluxes. The radial gap between the inner and outer coils should be such that unavoidable relative movement in the radial direction, due to say out-of-true running in the said bearings does not materially affect the coupling or the accuracy of measurement. The pairs of coils are preferably screened against each other in order to avoid undesirable capacitative interaction which would affect the bridge. Furthermore, the coils are preferably wound symmetrically and so that the ends have the same capacity relationship to earth. One embodiment of the invention is shown, by way of example, in the accompanying drawing, in which: Figure 1. is an electrical circuit diagram of an instrument working with carrier-frequency modulation, and Figure 2 is a longitudinal section through a coupling arrangement used in the instrument according to the diagram of Figure 1. In Figure 1, a conevntional bridge B corn- prises two measuring coils 1, 2 and two resistances 3, 4 which are adjustable for initially balancing the bridge. The bridge B is supplied with carrier-frequency current by an alternating current generator W. The output of the bridge is connected through an amplifier V to a phase-sensitive demodulator G and a filter network S which is connected in turn to an indicating or recording device A in the form of a moving coil instrument or oscillograph. The Bridge B is not directly connected to the generator W or to the amplifier V by means of slip rings, but is inductively coupled thereto by two pairs of coils Si, SO and S,, S t. As shown in Figure 2, the coils Sl and S, are disposed, at a short distance apart, side by side on a shaft member 5 which is secured, for
  4. 4. example by means of a threaded sleeve 6, to one end of a shaft to be examined, that is the rotating body upon which measurements are to be performed. It would be so secured in the same fashion as and, indeed, in place of slip-ring assemblies such as are described and illustrated in the aforesaid specifications. As in the said specifications, moreover, the measuring coils 1, 2 and coacting magnetic cores are mounted on respective parts of the said shaft or on the shaft and an inertia mass, depending upon the measurement to be effected. The coils Sl and S, are disposed in annular yokes, 7, 7a respectively, having a U-shaped cross-section which is open outwaidly. These yokes may be of laminated construction or may be slit radially to prevent eddy currents. A magnetic screen 9 is disposed around each yoke, from which it is separated by inserts 10 of electrical insulating material. A spacing ring 11 is disposed between the yokes The entire coil assembly Si, S,. 7, 7a is electrically insulated from the shaft member 5 by inserts 12. A bellshaped housing 14 carrying the coils S2 and S4 is mounted on the shaft member 5 by means of anti-friction bearings 13. The coils So, S, are also disposed in U-section laminated or slit yokes 15, 16, which are open inwardly to face the yokes 7, 7a and which are screened and insulated in the same way as the yokes 7, 7e and spaced apart by a ring 18. The coil assembly S 52, 84, 15, 16 is secured in the housing 14 by screws 19 by which it is clamped between an end ring 20 and a ring 21 forming part of the housing. The coils S, and S1 are located concentrically outside the coils Si and S, and in axial register therewith. The air gap L between the coils and S2 and between the coils S, and S4 is made as small as possible consistently with the requirement that it should be sufficiently large for unavoidable relative movement of the coils in the radial direction, for example due to out-of-true running in the bearings, to have practically no disturbing influence on the measurement. Moreover, the limbs of the U-sections of the yokes 15 and 16 enclosing the coils So and S1, for example, are made wider than those of the yokes 7 and 7a enclosing the coils Si and S,. They are made at least so wide that the path for the flux between the limbs of the yokes (for example between the yokes 7 and 15) is always fully maintained by the narrower lin;bs of the yokes 7, 7a remaining wititin the limits of the wider limbs of the yokes 15, 16, even if there is slight relative axial movement between the coils S1 and S, and the coils S2 and S1. The leads for the coils S2 and Sl are brought in through a hole 17 which is provided in the rounded end of the housing 14 and which is provided with a liquid-tight and gas-tight seal. The leads for the coils Si and So are brought out
  5. 5. through the shaft member 5 at the end provided with the sleeve 6 and are connected directly to the bridge B the whole of which is mounted on the shaft to be examined so as to rotate therewith. The aforesaid Specify cations illustrate how the measuring coils mag be mounted so as to rotate with the rotating body. In the present case, not merely the coils 1, 2, but the whole bridge, is similarly mounted. The coils Sl and S, and the coils SB and St are wound symmetrically, for example from the inner ends adjacent the rings 11, 18 towards the outer ends (to the right and the left in Figure 2). The spacing rings 11 and/or 18 may be proivded with radial bores for balancing purposes. If it is not possible to secure the coupling arrangement on the end of a shali: to be examined, the inner coils S1 and S, may be mounted on a bush to be pushed directly on to the said shaft. The operation of the circuit shown in Figure 1, apart from the coupling at the coils S,, S, and S3, S4, is per Se known and is described in the aforesaid Specifications: On disturbance of the balance of the bridge B by variation of the inductanoe of the coils 1, 2 due to relative movement between them and their cores, an alternating voltage modulated in dependence upon the said relative movement will appear across the output terminals of the bridge. This is fed by way of the coils S3, S4 to the amplifier V and the demodulator G. The demodulator output, which is substantially proportional to the aforesaid relative movement, is smoothed by the filter network S and supplied to the indicating or recording device A. What we claim is: - 1. An electrical instrument for measuring torsional forces or oscillations in a rotating body, in which measurement is effected by means of electrical variations produced in elements rotating with the said body, which variations are used to modulate a carrier-frequency current in a bridge connected through an amplifier and demodulator to an indicating or recording device, the bridge being also arranged to rotate with the said body and being coupled inductively, without the use of slip rings, both to a generator supplying the carrier frequency current and to the amplifier. 2. An instrument as claimed in Claim 1, wherein the coupling is effected by a pair of coils of which one is connected electrically to the generator and the other to input terminals of the bridge and a pair of coils of which one is connected electrically to the amplifier and the other to output terminals of the bridge, the second-named coils of each pair being connected to the rotating body so as to rotate therewith while the first-named coils are stationary, and the pairs of coils being disposed side by side. 3. An instrument as claimed in Claim 2, vvherein the coils connected
  6. 6. to the generator and to the amplifier are disposed concentrically around the outsides of the other coils of the respective pairs. 4. An instrument as claimed in Claim 2 or 3, wherein each of the coils is disposed in an annular yoke of U-shaped cross-section, the open sides of the U-sections of the yokes of inner and outer coils of respective pairs facing each other. 5. An instrument as claimed in Claim 4, wherein the limbs of the U-sections of the yokes facing each other are of different widths, so that slight relative axial displacement can take place between the inner coils and the outer coils without the narrower limbs passing outside the limits of the widths of the wider limbs. 6. An instrument as claimed in any one of Claims 2 to 5, wherein the coils are wound symmetrically. 7. An instrument as claimed in any one of Claims 2 to 6, wherein the coils connected to the bridge are mounted on a shaft member provided with means for securing it on the end of a shaft to be examined. 8. An instrument as claimed in any one of Claims 2 to 6, wherein the coils connected to the bridge are mounted on a bush to be pushed on a shaft to be examined. 9. An instrument as claimed in any one of Claims 2-8, wherein the pairs of coils are maintained apart axially by spacing rings. 10. An instrument as claimed in Claim 9, wherein the spacing rings are formed with bores for balancing purposes. 11. An instrument as claimed in any one of Claims 7 to 10, wherein the coils connected to the generator and amplifier are mounted in a housing in relation to which the shaft member or bush is rotatable. 12. An instrument as claimed in any one of Claims 4 to 11, wherein the yoke of each coil is screened from the yoke of the adjacent coil of the other pair. 13. An instrument as claimed in Claim 12, wherein electrical insulation is provided between the yokes and their screening means. 14. An instrument as claimed in Claim 13, wherein the yokes with their screening means are electrically insulated from the parts on which they are mounted. 15. An instrument as claimed in any one of Claims 2 to 14, wherein the coils connected to the generator and the amplifier are carried in a bell-shaped housing into which the electrical connections for the said coils are brought at the rounded end through a hole provided with a liquid-tight and gas-tight seal. - 16. An instrument as claimed in Claim 15, wherein the housing is mounted by means of anti-friction bearings on a member which is connectable to the rotatable body and which carries the coils
  7. 7. connected to the bridge. 17. The electrical instrument for measuring torsional forces or oscillations in a rotating body substantially as hereinbefore described with reference to the accompanying drawing. * GB784734 (A) Description: GB784734 (A) ? 1957-10-16 Device for producing a gas at low pressure from a supply of compressed or liquefied gas Description of GB784734 (A) A high quality text as facsimile in your desired language may be available amongst the following family members: BE544094 (A) CH339236 (A) DE1001298 (B) FR1118541 (A) BE544094 (A) CH339236 (A) DE1001298 (B) FR1118541 (A) less Translate this text into Tooltip [85][(1)__Select language] Translate this text into The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes. PAT-ENT 89 ? 7 E 1 ECATEON Daeo ppiainan iig o pee 7 84,7 34 B O< Date of Application and filing Complete Specification Dec30,1955. No 37351/55. Application made in France on Jan 4, 1955. Complete Specification Published Oct 16, 1957. Index at Acceptance:-Class 8 ( 2), F 2, CA (A 2: Bl BSX). International Classification: -F 253. COMPLETE SPECIFICATION Device for Produchng a Gas at Lowr Fressure from a supply of
  8. 8. Compressed or Liquefied Gas We, LA CARBONIQUE FRANCAISE, a French Body Corporate, residing at 171, Avenue Heari Barbusse, Bobigny, Seine, France, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a device adapted to produce a gas at low pressure from a supply of a compressed or liquefied gas, without freezing its water vapour content. Usually, when a gas is subjected to isenthalpic expansion m a conventional pressure17 reducer, freezing of its water vapour content takes place owing to temperature fall in the pressure-reducer Moreover, when the gas is obtained from a liquid by vaporisation, said freezing takes place most generally within the container of the liquefied gas owing to cold being generated by the vaporisation of the liquid Such a freezing may also cause detrimental ice formation on the apparatus parts. With a view to remove such drawbacks, it is an object of the present invention to provide an apparatus for producing a gas at low pressure from a supply of a compressed or liquefied gas, wherein the gas is drawn from its container and means are provided for heating the gas, while being vaporized if said gas is a liquefied gas, by conduction from a heated liquid up to such a temperature that after expansion the temperature of the expanded gas never falls down below 00 C thereby avoiding the freezing of the water vapour content of the compressed or liquefied gas when said gas is expanded. It is another object of the present invention to provide an apparatus of the character described comprising a closed chamber containing a liquid maintained at a predetermined temperature by any suitable heating means and a coiled pipe connected between the compressed or liquefied gas container and a pressurereducer, said coiled pipe being wholly lPice 3 s 6 d l immersed within the liquid in said chamber, the predetermined temperature being such that the temperature of the expanded gas flowing from the pressure-reducer is at least equal to 00 C The coiled pipe is made of a metal, such as steel or copper, having a high thermal conductivity and a breaking strength sufficient for resisting the high pressures experienced in operation. Any sudtable liquid may be used for heating the coiled pipe However, it is convenient to use a liquid having both a low volatility and a fairly high coefficient of thermal conduction or convection Such a liquid may be for example oil, mercury, or water, the latter being surmounted by oil for avoiding vaporisation losses. According to a preferred embodiment, the liquid in the closed chamber is heated by means of a resistor operating during periods of time the duration of which is controlled according to the rate of flow of the
  9. 9. fluid through the coiled pipe. Such a control is preferably made through a resistor-controlling thermostat actuated by pulses applied from a temperature-sensitive bulb located in the gas circuit between the coiled pipe and the pressure-reducer, such as a bulb in a sheath filled with oil or any other thermo-conductive liquid. Other features of the invention will appear in the following description of an embodiment thereof, with reference to the accompanying drawings, in which:Figure 1 is a diagrammatical view of an apparatus for expanding liquefied carbon dioxide, according to the invention; Figure 2 shows an alternative heating device for the apparatus illustrated in Figure 1; Figure 3 shows a modified inlet of the coiled pipe as may be used for gases with a triple point, such as carbon dioxide, in order to avoid failure in operation. The invention will be described hereafter as applied to the expansion of liquefied carbon dioxide, but it should be understood that the -v 784,734 illustrated apparatus parts may be used for any other liquefied or compressed gas. Referring to Figure 1, a plunger pipe 1 is disposed in a liquefied carbon dioxide storage bottle 2 and extends to the bottom of said bottle Said plunger pipe I is connected to the bottle outlet valve 3 provided with a safety capsule 4 of a known type, such as a bursting capsule The valve 3 is connected through a pipe 5 to a connecting member 6 on which is fitted another bqrsting capsule 7 Said member 6 is connected through a pipe 8 to a coiled pipe 9 made of copper or steel itself connected through a pipe 10 to a closed chamber 11. Said chamber 11 is also connected through a pipe 12 to a pressure-reducer 13 from -which the expanded gas is delivered through the outlet pipe 14 Pressure gauges 15, 16 are connected to the pipes 12, 14 respectively for indicating the gas pressure before and after expansion. The coiled pipe 9 is arranged within a closed chamber 17 filled with a liquid having a low volatility and a high coefficient of thermal conduction or convection, such as oil. A level meter 18 extending into the chamber 17 through the filling port of said chamber is provided for measuring the liquid level A resistor 19 of cylindrical shape also extends into the chamber 17 through the top thereof and is arranged coaxially with the coiled pipe 9 The resistor 19 is energized under the control of a thermostat 20 actuated by pulses supplied from a temperature-sensitive bulb accommodated within a sheath 22 filled with oil or any other thermo-conductive liquid and welded to the wall of the chamber 11. The above described device operates as follows:When the valve 3 is opened, the compressed gas flows from the bottle 2 through the coiled
  10. 10. pipe 9 to be heated therein by the thermo-conductive liquid contained in the chamber 17 wherein said liquid is subjected to the action of the heating resistor 19 The gas flows from the coiled pipe 9 through the pipe 10 into the chamber 11 and thence through the pressurereducer from which it is delivered through the pipe 14. If the rate of flow through the coiled pipe increases, the temperature will tend to fall within the chamber 11, and the bulb 21 will respond to such temperature fall by supplying a pulse to the thermostat 20 which will switch on the electric current to feed the resistor 19 so as to restore the predetermined temperature The temperature to be maintained within the chamber 11 depends on the pressure prevailing in the bottle 2 and may be determined by means of the isenthalpic expansion curves of the entropy diagram of the gas in such a manner that the final temperature, after expansion, will be higher than O C By way of example, for carbon dioxide, the temperature in chamber 11 should be maintained at 550 C. when the gas pressure in the bottle 2 is 710 lbs /sq in, and at 755 C when said pressure is 1140 lbs /sq in. The bursting capsule 7 serves to avoid a rupture of the coiled pipe 9 which may be 70 caused by the surge of pressure occurring when, inadvertently, the bottle outlet valve 3 and the pressure-reducer 13 are closed simultaneously. Figure 2 shows an alternative embodiment 75 of the heating chamber which permits to take advantage of the convection effect in the heating liquid and, at the same time, to use a liquid such as water which satisfactorily provides the characteristics required for the heat 80 ing liquid However, in this case, the mass of water 23 is slu mounted Hithin the chamber 17 a by a layer of oil 24 for the purpose of preventing water vaporisation The cylindrical resistor 19 a, in that case, extends 85 through the bottom of the chamber 17 a. In the case of substances having a triple point in their phase equilibrium diagram, such as carbon dioxide, an inadvertent opening of the valve 3 before the heating device has been 90 made operative may cause a formation of carbon dioxide snow within the pressurereducer 13, thus preventing the outlet of expanded gas through the pipe 14 In such an occurrence, there is no remedy but to remove, 95 clean and mount back the pressure-reducer. For avoiding such a drawback, the pipe 8 a illustrated in Figure 3 terminates short of the coiled pipe 9 and opens into a chamber 25. equal to that of the passage through the outlet 100 The inner cross-section of the pipe 8 a is valve 3 If said valve and the pressure-reducer 13 are opened before the heating device is operative, the compressed gas flowing from the pipe 8 a is expanded in the chamber 25 and a 105 mass of carbon dioxide snow builds up in said
  11. 11. chamber and stops up the inlet into the coiled pipe 9 The gas flow is thus checked However, when subsequently the heating device is put in operation, said carbon dioxide snow 110 mass is immediately vaporised and the flow is thus restored without any part having to be disconnected from the apparatus. * Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p * GB784735 (A) Description: GB784735 (A) ? 1957-10-16 Improvements in pressure seal structures for a movable rod-like element Description of GB784735 (A) PATENT SPECIFICATION 784,735 Date of Application and filing Complete Specification: Dec 30, 1955. No 37451 /55. Application made in United States of America on Jan 14, 1955. r,,, 'Complete Specification Published: Oct 16, 1957. Index at Acceptance:-Class 122 ( 5), B 13 (B 3 A 3:133 A 8: B 3 E 1: CX: D: G). International Classification:-FO 6 J. COMPLETE SPECIFICATION Improvements in pressure seal structures for a movable rod-like element We, GENERAL ELECTRIC COMPANY, a Corporation of the State of New York, United States of America, having its office at Schenectady 5, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-
  12. 12. This invention relates to a pressure seal structure for preventing appreciable leakage around a movable rod-like element extending through a wall of a chamber containing gas under either low or high pressure. In the chemical, metallurgical and related arts an increasing use is being made of reaction and treatment apparatus involving vacuum or very high pressure chambers. One of the difficulties encountered in the use of such apparatus is the provision of adequate seals about movable elements which extend -through the chamber walls These elements may have a variety of functions but usually they must move freely with respect to the opening in the chamber wall For example, such an element may have a rod or shaft-like configuration and be used to manipulate apparatus or materials within the chamber, may serve as a drive shaft for mechanism within the chamber, may serve to conduct material to or from the chamber, or perform any other function which may require relative motion between the element and the container wall structure. A particularly difficult sealing problem has been encountered in the metal casting art in the adaptation of continuous casting apparatus to the vacuum melting furnace technique Conventionally, such continuous casting apparatus usually consists of a melting furnace to which material to be melted is charged by any suitable means The molten material is continuously tapped from the crucible of the furnace into a tubular lPrice 3 s 6 d l mould, the molten material solidifying in the upper portion of the mould and the solid ingot or bar thus formed being continuously extracted through the open bottom of the mould The specific details of such continuous casting apparatus are well known and form no part of the present invention. The extracted bar or ingot so produced is usually quite hot and frequently does not have a smooth surface Where the material being continuously cast in this manner does not require melting in a vacuum such as, for example, brass or other similar alloys, the various operations may be carried out in the atmosphere without difficulty However, certain molten metals and alloys react quite readily with gases of the atmosphere and are usually commercially produced in vacuum furnaces of the batch type in which it is sometimes necessary to maintain pressures of the order of 10-2 to 10-5 mm of mercury In order to operate such a continuous casting apparatus in an evacuated enclosure, provision must be made for the continuous extraction of the hot rod-like bar or ingot from the evacuated enclosure without loss of vacuum Because the temperature of newly cast ingots of metals such as titanium, for example, may be of the order of 10 00 C or higher, a deformable seal of the gland and stuffing box type is unsuitable due to rapid destruction of the packing material Furthermore, a seal which
  13. 13. depends primarily upon an intimate physical contact between the sealing element and the surface of the ingot to perform its sealing function is unsatisfactory primarily due to the irregularity of the surface of the ingot. In addition to providing an adequate barrier to gases of the atmosphere, such a seal must not be excessively large. The invention provides a tubular seal structure particularly useful with such a vacuum chamber and rod-like element or bar, which includes supplementary annular Price 25 P 784,735 pumping chambers or bustles interposed between the rod-like bar element and the opening in the wall structure of the vacuum chamber by means of which gases leaking past the periphery of the rod-like element may be pumped away The pumping chambers or bustles are separated from each other by means of metallic flexible conical gas traps which permit the maintenance of sizeable pressure differentials between adjoining chambers In this manner, a gross pressure differential may be maintained across a series of bustle chambers which is the sum of the individual pressure gradients across each chamber. While the seal of the invention is particularly suited for overcoming the problems involved in extracting a hot bar or ingot from a vacuum chamber, it is equally suitable for other and specifically different uses. For example, the improved seal is equally adaptable for inserting a rod-like element into a vacuum chamber In this manner, material to be melted in a vacuum enclosed continuous casting apparatus may be continuously charged into the furnace crucible without loss of the vacuum by passing a rod-like element of the material through an appropriately located seal in a wall of the vacuum chamber Additionally, in the event that a consumable electrode arc furnace is employed in such an apparatus, the rod-like element may constitute the consumable electrode The seal may also be employed where the relative motion between the rod-like element and wall structure is rotary or reciprocating The chamber may in any case contain gas at an elevated pressure instead of being evacuated. A tubular pressure seal structure for regulating and controlling gas leakage around a rod-like element extending longitudinally through and movable in an aperture in a wall adapted to separate a body of gas at high pressure from a body of gas at a lower pressure comprises, according to this invention a substantially tubular element adapted to be secured to and extend from the wall and to encompass the aperture therein, the tubular element having an internal passage therethrough of a size and configuration similar to but larger by a small but discrete amount than the crosssection of a rod-like element which is to pass therethrough, a plurality of spaced pairs of resilient sheet
  14. 14. metal gas trap elements secured at their outer edges to the interior of the tubular element and having centrally disposed resiliently expansible apertures through which the rod-like element is to pass, the portions of the trap elements defining the apertures being adapted to maintain a substantially continuous frictional line-contact with the periphery of the rod-like element whereby a plurality of substantially closed annular chambers are adapted to be formed between the interior of the tubular element and the rod-like element, and means whereby the gas pressure in at least one of the annular chambers may be modified 70 The invention will be better understood from the following detailed description of the accompanying drawing in which: Fig 1 is a fragmentary sectional view of a schematically represented vacuum chamber, 75 rod-like element and sealing means taken along line 1-1 of Fig 2; Fig 2 is a fragmentary sectional view taken along line 2-2 in Fig 1; Fig 3 is a detail view of a conical gas 80 trap element; and Fig 4 is a large scale fragmentary detailed view of a gas trap element. With particular reference to Fig 1, a portion of the wall structure of a vacuum 85 container 1 is provided with an aperture 2. Vacuum container 1 is provided with a vacuum source or pumping means of any suitable construction which has not been shown A rod-like element 3 extends 90 through aperture 2 from the interior of the vacuum chamber and is dimensioned so that it is slightly smaller than aperture 2 A tubular seal structure generally indicated by reference numeral 4 comprises a tubular 95 structure 5 secured to the container and extending outwardly from the periphery of aperture 2 A helical passage 6 may be provided in element 5 with a confining element 7 for a purpose to be later disclosed 100 A flange 8 is formed at the outer end of element 5 and is provided with a continuous recess 9 encircling the open end of tube 5. Subjacent to flange 8 and bearing thereon is a plate element 10 containing an internal 105 passageway 11 which is located adjacent recess 9 A sealing element or ring 12 of resilient material such as a suitable elastomer is contained in recess 9 and compressed therein by plate-like element 10 to form a 110 seal Plate-like element 10 is centrally apertured at 13, the size and configuration of the aperture being substantially identical to the internal opening of tubular element 5 and coinciding therewith 115 A bustle chamber-forming element 14 is provided with a substantially cylindrical aperture 15 which is somewhat larger than aperture 13 of plate 10 and is concentric therewith The upper surface of element 14 120 is positioned against the lower surface of element 10 and is provided with a continuous recess 16 which is similar to recess 9 in flange 8 and is located adjacent passage 11 in element 10 Contained and compacted 125
  15. 15. within recess 16 is sealing element 17 similar in all respects to ring 12 The bottom surface of element 14 contains a recess 18 and sealing ring 19 similar in all respects to recesses 9 and 16 and rings 12 and 17 130 verse dimension, the slits may substantially 65 close. While in Fig 1 the seal is shown with only two bustle chambers, it is to be appreciated that as many or as few bustle chamber forming elements and the intervening spacer 70 plates such as element 20 may be assembled in one array as desired, the various elements of such an array being clamped together by any suitable and preferably removable means Such a clamping or securing means 75 has been illustrated by the bolt and nut assemblies shown, for example at 33. In the application of the seal of the invention to the extraction of a continuously cast ingot or bar from a vacuum chamber 80 as disclosed previously, rod-like element 3 represents a hot, newly cast ingot or bar continuously moving outwardly through aperture 2 In order to reduce the transfer of heat by conduction along tubular element 85 a cooling media such as water is preferably circulated in helical passage 6 Further, in order to maintain the ring seals shown at 12, 17, 19, for example, at a suitable low temperature, a cooling media may also be 90 circulated through passages 11, 21 and 26, as excessive heat may tend to destroy the seals The outer dimension of the newly cast ingot 3 is somewhat larger than the aperture in trap elements 30 and causes the 95 material between the radial slits 32 in the conical section 31 of these elements to flex slightly outwardly Under these conditions slits 32 open slightly to form small elongated triangular openings, as shown in Fig 4 In 100 Fig 4, the size of the triangular openings have been exaggerated for clarity Since a relatively tight line-contact is maintained between the inner periphery of the central aperture of element 30 and the outer peri 105 phery of element 3, gas flow from one side of a gas trap element 30 to the outer side is substantially limited to that amount of gas which can pass through the very small apertures formed by the slits 32 It should be 110 noted that the line-contact between elements and element 3 is maintained not only by the resilience of the sheet metal, but also by the pressure drop across each element 30. Therefore, with respect to any given bustle 115 chamber forming element, for example 14, the upper and lower trap elements 30 associated therewith in co-operation with the oiiter periphery of element 3 form a substantially enclosed annular compartment 120 which may be connected to a vacuum source by means of a conduit such as shown at 34. The outer end of the conduit portion may be conveniently provided with a recess for the reception of a ring seal as shown at 35 125 to provide a vacuum tight joint to the bustle chamber vacuum source.
  16. 16. Since each of the bustle chambers that may be used in such an array is substanSubjacent to the bottom surface of plate 14 and bearing thereagainst is spacer element which is provided with an internal passageway 21 which is adjacent recess 18 and ring 19. Subjacent to spacer-element 20 and bearing thereagainst is a bustle chamber element 22 which is similar in all respects to bustle chamber element 14 Subjacent to and bearing against the lower surface of bustle chamber element 22 is a terminal plate-like element 23 which has an aperture 24 of substantially the same dimension and configuration as aperture 13 of plate-like element 10. Aperture 24 is counterbored as shown in 25 for a purpose which will be discussed in detail later Element 23 is provided with a passageway 26 as shown. Rectangular cross-sectioned recesses or counterbores 27 and 28 are provided in the upper and lower surfaces of identical bustle chamber forming elements 14 and 22 as shown Clamped within recesses 27 and 28 by means of adjacent plate-like elements 10 and 20, for example, are the rim portions 29 of identical gas trap elements 30 Gas trap elements 30 (as shown particularly in Fig 3) are centrally apertured and have a frustoconical portion 31 extending from flange 29. The internal diameter of flange 29 is substantially the same as the internal dimension of aperture 15 of element 14 and recess 25 of element 23, while the internal dimension of the aperture formed by conical section 31 is slightly smaller than the external dimension of rod-like element 3. The gas trap elements 30 are preferably formed from a resilient heat-resistant metallic sheet material which resists plastic deformation even at elevated temperatures. In order to retain the resiliency of the conical section 31 and to permit rod-like element 3 to pass through the central aperture of the trap element 30 while maintaining a constant frictional engagement between element 3 and trap elements 30, spaced slits 32 are provided in conical section 31 and extend from the aperture substantially to flange portion 29 in a radial direction In this manner as element 3 passes through the central apertures of trap elements 30, the converging portions 31 of the trap elements maintain a frictional contact with the peripheral surface of element 3 The intersection of each of these elements 30 with element 3 defines a substantially continuous line encircling the element 3, i e each element 30 maintains a substantially continuous frictional line contact with element 3 It is to be noted that the slits 32 are preferably formed by a shearing operation or the like rather than a punching or slotting operation so that, if irregularities in the surface of the rod-like element tend to reduce its trans784,735 tially identical, it is not
  17. 17. considered necessary to describe other identical structures shown associated with element 22 than the recess structure and central aperture of the terminal end plate 23 The counterbored recess 25 in end plate 23 is provided in order to accommodate the flexure of the terminal gas trap 30 The dimension and configuration of aperture 24 of plate 23 is only slightly larger than the external dimension and configuration of element 3 in order to restrict the free flow of atmospheric gases into the bustle chamber seals. It will therefore be seen upon inspection that only a limited amount of the gases of the atmosphere may flow through the restricted opening formed between the outer periphery of element 3 and aperture 24. Only a limited amount of these gases will pass through the extremely small apertures 32 of trap element 30 into a first bustle chamber At this point the vacuum pumping means in communication with the chamber will remove a substantial portion or amount of the gas Gas flow from the first chamber into a succeeding chamber is further restrained and reduced in amount by the necessity of the gas having to flow through the small apertures 32 of two more gas traps 30 In the next bustle chamber the quantity of gas is again reduced and as the gas progresses from chamber to chamber with corresponding reductions in amount at each chamber, the gas pressure and consequently the amount of gas present will become reduced to an amount within the pumping capacity of the main vacuum chamber 1 When this predetermined point is reached the residual gas is permitted to flow into the main vacuum chamber and is then pumped out in the due course of the operation of the apparatus. Under some circumstances, it may be undesirable to permit any gas to flow into the vacuum chamber In such a case, sufficient pumping capacity may be provided for the final bustle chamber so that it cooperates with the chamber's vacuum source, to maintain the vacuum of the chamber In this circumstance the flow of gas in the annular conduit contained in tubular element is in the direction of the bustle chamber and away from the vacuum chamber. While the foregoing discussion and the embodiment illustrated has been directed to a seal for the extraction of a rod-like element from a vacuum chamber, a substantially identical array of these same elements may be used to insert a rod-like element into a vacuum chamber, as suggested previously. In both arrangements and as illustrated in the drawing, the direction of convergence of the conical portions 31 of gas trap elements is in the direction of motion of element 3. The various elements comprising the seal are readily disassembled and replaceable and, further, similar elements are interchangeable, permitting flexibility in installation and maintenance.
  18. 18. A further particular practical advantage 70 of the seal of this invention is that it may be readily altered by the addition or subtraction of bustle chambers to fit the particular vacuum condition requirements of a particular operation or reaction to be performed 75 in the vacuum chamber By the employment of the metallic gas trap elements 30, a considerable variation in the number of bustle chambers may be accomplished without greatly increasing the length of the seal 80 This is important in industrial installations where space is at a premium and extensive structural changes in permanently installed heavy equipment, such as a vacuum furnace, for example, cannot be tolerated 85 While the foregoing disclosure has described the application of the seal structure to either the continuous insertion of a rodlike element into a low pressure chamber or the continuous extraction of such an ele 90 ment from such a chamber, it should be appreciated that substantially the same seal structure is equally adapted to the insertion or extraction of a rod-like element from a high pressure chamber In such an appara 95 tus, gas at high pressure would be supplied by means of a pump or the like to the toroidal bustle chambers. In practice, of course, the number of serially arranged bustles or pumping cham 100 bers and gas trap elements to be used in a particular installation will depend upon several factors In general, these factors are, the pressure desired to be maintained within the vacuum container, the pumping 105 capacity of the vacuum source of the container, the size and number of slits in the gas trap elements, and the pumping capacities of the vacuum sources attached to the bustles For purposes of this disclos 110 ure it will be assumed that the external pressure of this system is atmospheric although it is to be noted that the invention is not necessarily limited to use in that pressure range 115 From the foregoing it may be seen that an efficient vacuum sealing apparatus is provided whereby a longitudinally movable rodlike element, particularly a hot newly cast ingot of metal, may be extracted through a 120 wall of a vacuum container and which cooperates with the container and the rod-like element or ingot to substantially prevent leakage of atmospheric gases around the ingot into the vacuum container While the 125 specific disclosure of the invention illustrates a rod-like element or ingot having a circular or substantially circular cross-section co-operating with a seal structure which forms a substantially circular cylindrical 130 784,735 2 A pressure seal structure as claimed in claim 1 for a rod-like element movable in a longitudinal direction through the aperture, in which the gas trap elements are frusto-conical, and are arranged with the conical portions of each of the elements converging in the direction of longitudinal movement of the rod-like element.
  19. 19. 3 A pressure seal structure as claimed in claim 2 having a plurality of radially disposed slits provided in the conical portion of each of the trap elements permitting resilient expansion of their apertures to accommodate the passage of the rod-like element. 4 The combination of a pressure chamber, a gas pumping means for the chamber, an aperture in a wall of the chamber, a straight rod-like element continuously passing through and substantially filling the aperture, and a substantially tubular seal structure as claimed in claim 2 or 3 encompassing the aperture and closely surrounding a portion of the outwardly projecting length of the rod-like element, the annular spaces defined by successive pairs of the trap elements constituting bustle chambers, and each so-defined bustle chamber being provided with a gas pumping means. A pressure seal structure substantially as herein described and shown in the accompanying drawings. J W RIDDING, Chartered Patent Agent, 64-66, Coleman Street, London, E C 2, Agent for the Applicants. passage, it is to be understood that these elements may be formed with other and specifically different cross-sectional configurations without departing from the scope of the appended claims. * Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p * GB784736 (A) Description: GB784736 (A) ? 1957-10-16 Improvements in or relating to heat exchange apparatus Description of GB784736 (A) PATENT SPECIFICATION 784,736 Date of Application and filing Complete Specification: Feb
  20. 20. 8,1956. No 3931156. Application made in United States of America on Feb 14, 1955. Complete Specification Published: Oct 16, 1957. Index of Acceptance:-Classes 83 ( 2) A 158; and 83 ( 4), Q( 2 A 2: 2 A 13: 4). International Classification,:-B 23 d, p. COMPLETE SPECIFICATION Improvements in or relating We, WESTINGHOUSE ELECTRIC INTERNATIONAL COMPANY, of 40 Wall Street, New York 5, State of New York, United States of America, a Corporation organised and existing under the Laws of the State of Delaware, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to heat exchange apparatus and more particularly to a method of manufacturing plate and tube heat exchangers of the type used as condensers in domestic refrigerator systems. Refrigerant heat exchangers have been constructed in the past in which a serpentine refrigerant carrying tube is attached to a plate member preferably made from metal or other good heat-conducting material The plate member presents a large surface area for efficient heat exchange purposes and provides the necessary rigidity for the structure to permit it to be easily handled and mounted A number of methods have been proposed for securing the tube intimately to the plate such as is necessary to give good heat transfer between the two Some of these methods involve the formation of grooves on the plate member to receive the tube, and further forming operations on the plate to cause the plate to grip and hold the tube in place It is with this general method of manufacture that the present invention is concerned. The chief object of this invention is to provide an improved method of forming a tube and plate type heat exchanger. A further and more specific object of this invention is to provide an improved method of forming the plate member of a plate and tube type heat exchanger to effect efficient and uniform engagement between the plate and tube whereby the said tube is effectively clinched on to the plate member. lPrice 3 s 6 d l to heat exchange apparatus With the above objects in view, the invention resides, basically, in the method of forming a tube and plate heat exchanger which comprises forming a groove in the plate, working said plate to decrease the depth of said groove While confining the regions of said plate adjacent said groove whereby the portions of said plate which form the upper walls of the groove and
  21. 21. other portions of said plate immediately contiguous to said first named plate portions are formed into a double wall rib at either edge of said groove, subsequently assembling the tube in the groove thus formed, with the said double wall ribs, and acting on said ribs to clinch them over said tube. In order that the invention may be more clearly understood and readily carried into effect, reference will now be made to the accompanying drawings, in which: Fig 1 is a broken elevational view of a plate and tube type heat exchanger manufactured in accordance with this invention; Fig 2 is an end view of the heat exchanger shown in Fig 1; Fig 3 is an enlarged fragmentary sectional view showing the initial groove forming operation on the heat exchanger plate member; Fig 4 is an enlarged fragmentary sectional view showing one of the die combinations used in a further step in the forming of the heat exchanging plate; Fig 5 is another view of the die combination shown in Fig 4, and showing the forming operation performed by this die combination; Fig 6 is an enlarged fragmentary sectional view showing the clinching operation performed on the plate member to clamp the tube in place; and Fig 7 is a fragmentary sectional view showing a bending operation performed on the plate and tube members. In Figs 1 and 2 of the drawings there is shown a plate and tube type heat exchanger made in accordance with this invention and 2 784,736 having a configuration suitable for use as a condenser for a domestic refrigerating unit. As shown in Fig 1, the heat exchanger consists of a serpentine refrigerant carrying tube 12 secured to a plate member 13 The tube 12 is held in place on the plate 13 by virtue of the manner in which the plate 13 is formed about the straight portions 14 of the tube as will be explained more fully hereinafter The U-shaped connecting portions 16 of the tube 12 extend beyond the longitudinal edges of the plate 13 The longitudinal edges of the plate 13, as well as the connecting portions 16 of tube 12, are curved out of the plane of the body of the plate as shown in Fig 2 and have flanged edge members 17 attached thereto which extend the full length of the plate 13 The curved plate 13 together with the edge members 17 form a channel structure suitable for mounting on the back of a domestic refrigerator, and mounting holes 18 are provided in the edge member 17 for that purpose. The heat exchanger is manufactured in the following manner; A flat plate of good heat conducting material, such as steel, and having suitable dimensions is first placed between the two die members indicated at 19 and 21 in Fig 3 and a plurality of grooves or depressions 22 are formed across the width thereof, one at a time In this operation a press having a single die combination of the configuration shown in Fig 3 is utilized and the plate 13 is fed
  22. 22. through the press in predetermined steps of movement to space the grooves along the plate 13. In the operation illustrated in Fig 3, the plate 13 is formed to provide the grooves 22 with substantially straight upper side wall portions 23 The depth of the groove 22, from the upper edges 24 of the side walls 23 to the bottom of the groove is greater than the outside diameter of the tube subsequently to be positioned in the groove The plate 13 is also formed with portions 27 thereof which are contiguous to the groove side walls 23 and displaced from the plane of the deformed portions of the plate 13. A gradually sloping region 28 joins the contiguous portions 27 to the undeformed portion of the plate 13 It is not essential to this invention that plate portions 27 be displaced from the plane of plate 13, as shown, but rather the groove top edge 24 may lie in the same plane as the undeformed portions of plate 13 The purpose of this additional deformation of plate portions 27 and 28 is to ensure that all of the tube 14 will lie on one side of the plate 13 in the finished heat exchanger This leaves one surface of the plate 13 free of protuberances and simplifies attachment of the plate 13 to edge members 17. After the above described initial grooving operation has been performed on the plate 13, the plate is placed in a press having a plurality of die combinations like the one shown in Figs 4 and 5 Figs 4 and 5 show a die combination for working a single 70 groove of the plate 13 and it is to be understood that in this operation all grooves are preferably worked simultaneously in a press containing a die combination for each groove By working all grooves of the plate 75 13 simultaneously, any inaccuracies in the spacing between the grooves resulting from the initial individual groove forming operation can be corrected. In Fig 4, the die members for performing 80 the second forming operation on the plate 13 are shown in the position which they assume upon initial contact with the plate 13 The portions of plate 13 adjacent to the groove 22, including sloping portions 28, are 85 gripped between upper and lower holding dies 29 and 31 The faces of die members 29 and 31 are so constructed as to grip these portions of the plate 13 and retain the shape imparted thereto during the initial forming 90 operation Plate portions 27, contiguous to the groove 22, are however not confined between the holding die The upper holding die member 29 is slotted at 32 to receive a follower plunger 33, the lower end of 95 which projects beneath the face of die 29 and is shaped to fit into the plate groove 22. The follower plunger 33 is biased downwardly with respect to die member 29 by means of springs 34, only one of which is 100 illustrated
  23. 23. The springs 34 are carried in a recess 35 in a back-up plate 36 rigidly attached to the die member 29 and transmit force to the follower plunger 33 through a T-shaped bar 37 The lower holding die 105 31 is also slotted at 38 to receive a plunger die 39 having a semi-circular channel 41 in its upper surface adapted to receive the bottom wall of plate groove 22 The plunger die 39 is rigidly attached to a lower backing 110 plate 42 A number of springs (not shown) are interposed between the lower holding die 31 and the lower backing plate 42 to move these die members away from one another as shown in Fig 4 when the forming 115 press is open. As mentioned previously, Fig 4 illustrates the position of the die members at the beginning of the second forming step It can be seen that the follower plunger die 33 120 has been forced into plate groove 22 and is clamping the bottom wall of groove 22 against the lower plunger die 39 This initial engagement of the grooved plate 13 by the die members of this forming opera 125 tion positions the grooves 22 with respect to one another and corrects any variations in spacing between the grooves 22 which may have occurred during the initial groove forming operation when the grooves were 130 784,736 784,736 formed individually The importance of having the grooves properly positioned with respect to one another can be appreciated when it is understood that additional forming operations are to be performed on the plate by dies designed to work all of the grooves simultaneously, and accurate spacing of the grooves is essential for such simultaneous forming operations Furthermore, a preformed serpentine tube is to be placed in these grooves in a subsequent operation If the grooves are improperly spaced from one another, difficulty may be experienced by the operator in assembling the preformed tube. Further forming of the plate takes place as the press is closed to bring the die members 31 and 42 together Fig 5 illustrates the positions assumed by the die members shown in Fig 4 when the press is completely closed and the plate member 13 is worked It can be seen that the closing of the press has forced lower plate member 42 into engagement with the lower holding die 31, moving plunger die 39 upwardly in slot 38 The lower end of follower plunger 33 holds the bottom of groove 22 in channel 41 of plunger die 39 to retain the smooth curvature of the bottom of groove 22 as the plate material defining the groove is forced upwardly by plunger die 39 Follower plunger 33, carried by the upper holding die 29, is forced upwardly against the action of spring 34 This upward movement of the plate material in the groove 22 pulls the unconfined plate portions 27 up into engagement with curved projections 43 on the face of holding die 29 As plate portions 27 engage projections 43 and movement of the groove plate material continues upwardly, the upper walls 23 of the
  24. 24. groove are rolled outwardly, forming a sharp break at 44. This rolling or breaking of the upper groove wall 23 shortens the depth of the groove 22 and forms from the upper walls 23 and plate portions 27 double wall ribs 46 at either side of the groove 22 The plate 13 is thus prepared for the attachment of a tube. The plate 13 is next placed in another press for performance of the clinching operation illustrated in Fig 6 A preformed serpentine section of tube 12 is assembled with the straight portions 14 thereof lying in grooves 22 The die members in this operation are shaped as shown in Fig 6, in which the lower die 47 has a surface configuration such as to receive and support a grooved portion of plate 13 The upper die 48 is constructed with a pair of projections having oppositely inclined faces adapted to act on the upstanding ribs 46 adjacent groove 22 to bend or clinch these ribs 46 over the exposed surface of tube 14 to clamp the tube in place within groove 22. Again this clinching operation is performed on all grooves simultaneously, only the die member for one groove being illustrated. With the tube 14 thus attached to the plate 13, this assembly is placed in a bending die combination illustrated in Fig 7, in which the edges of the plate 13 are bent upwardly, giving the plate and tube assembly a channel shape configuration. The upper and lower die members 51 and 52 for performing this platebending operation are not illustrated in detail It is to be understood, however, that these die members 51 and 52 are provided with surface configurations such as to prevent damage, during the bending operation, to the plate grooves 22 and the tube 12 clamped therein. Such dies may be constructed from knowledge presently available in the art and no detailed description is deemed necessary here After the plate member 13 is removed from the bending dies 51 and 52, the edge plates 17 shown in Figs 1 and 2 are attached thereto by welding or other suitable means to complete the heat exchanger. From the foregoing it will be apparent that this invention provides a novel and improved method of attaching a tube to a plate in heat exchange apparatus It will further be appreciated that the novel steps employed in forming the plate to receive the tube result in a simple, yet effective, manner for clamping the tube in place in the groove of the plate. * Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015
  25. 25. * Worldwide Database * 5.8.23.4; 93p * GB784737 (A) Description: GB784737 (A) ? 1957-10-16 Flame tip or nozzle for welding blowpipes and method of making it Description of GB784737 (A) PATENT SPECIFICATION io 4574 %t Date of Application and filing Complete Specification: April, 17, 1956. No 11701/56 Application made in Australia on April 20,1955. " 7 -',Complete Specification Published: Oct 16, 1957. Index at Acceptance:-Class 83 ( 2), A 113. International Classification:-B 23 p. COMPLETE SPECIFICATION Flame tip or nozzle for welding blowpipes and method of making it We, THE BRITISH OXYGEN COMPANY Li Mi TED, a British Company of, Bridgewater House, Cleveland Row, St James's, London, S.W 1, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - It has been proposed to make tapered nozzles or flame tips for welding blowpipes by swaging one end of a tube Hitherto, however, such swaging operations, because of the extensive tube diameter reduction involved, have caused formation of small ripples or waves in the internal surfaces of the tubular tip, and these, in the final stages of swaging frequently fold or otherwise become accentuated thus causing undesirable irregularities in the bore surface. These irregularities are particularly objectionable as they prevent obtaining what is usually referred to as a good " gas stream, namely, one of uniform delivery due to absence of turbulence and the like The object of the present invention is to produce a tip by swaging in such a manner that the tip is free of the objectionable feature referred to above, and also in a manner which ensures the final outlet nozzle bore to be perfectly smooth, straight and otherwise possessed of all the
  26. 26. accuracy obtainable by first-class machining operations, as distinct from swaging or the like. According to this invention a welding blowpipe tip is made from a piece of malleable tube and an insert tip element or sleeve which during the course of manufacture becomes fixedly united in what becomes the outlet end of the tube The inserted tip element comprises a cylindrical open-ended sleeve whereof the bore is drilled or otherwise accurately formed to the required nozzle outlet size, or it may be drilled to some greater size and subsequently brought lPrice 3 s 6 d l to the required final size by a swaging operation in which the bore diameter reduction is not sufficient to involve the swaging disabilities referred to above The external wall surface of the inserted sleeve is furnished with one or more peripheral grooves or beadings for anchorage purposes as referred to later herein. The method according to the present invention comprises the steps of: inserting a tip sleeve, as a close fit, inside the outlet end of a blowpipe tube; inserting a mandrel, whereof the lateral dimensions are the same as those required of the bore of the finished tip, inside the inserted sleeve; and swaging the outlet end of the tube (with the sleeve in it) thereby causing the tube to grip the sleeve tightly and leave the bore of said sleeve shaped in close correspondence with the outside of the mandrel. Examples of the invention are illustrated in the drawings herewith All the figures of the drawings are medial cross-sectional views. -Fig shows the outlet end of a blowpipe tube and -a tip sleeve ready, for insertion therein Fig 2 repeats Fig 1 but with the sleeve inserted. Fig 3 repeats Fig 2 but with the swaging mandrel inserted. Fig 4 is substantially the same as Fig 3 but illustrates a minor modification. Fig 5 shows a finished flame tip. Fig 6 shows part of a blowpipe tube to illustrate another minor modification. The outlet end 7 of the blowpipe tube may be preliminarily swaged as indicated at 8 The tip sleeve 9 is made as a close fit for the bore of the end 7 and is inserted therein as shown in Fig 2 The sleeve is furnished with means which assist its eventual anchorage within the blowpipe tube by swaging These means are preferably circumferential grooves 10 Obviously, 1 i'' ' Price 33 p an, Athey could be projecting circumferential beadings, but grooves, such as 10, are better for manufacturing simplicity. The finished bore of the sleeve may be plain cylindrical (as shown in Fig 1) or its upstream end may be countersunk, doubly countersunk, rounded, or otherwise shaped as may be required The sleeve may be
  27. 27. initially bored as of the required final size as shown in Fig 4, or it may be first bored somewhat larger than the required final size as shown in Figs 1-3 and as explained below. In Fig 3 a sleeve is shown which has its bore oversize and entered by a mandrel 11. Upon circumferentially applied compressive swaging, the metal of the tube is forced into the grooves 10 and the bore of the sleeve 9 is forced into conformity with the mandrel as shown in Fig 5. In Fig 4 a sleeve is shown whereof the bore has been initially formed as of the required final dimensions Upon the mandrel 11 being entered, as shown, and followed by swaging as referred to above, the result is also as shown in Fig 5. Fig 6 shows the outlet end of a blowpipe tube which is the same as those described above except that a counterbore 12 is provided to receive a sleeve (such as 9) Provision of such a counterbore facilitates sleeve insertion, by providing a stop against which the sleeve may abut, and also helps to keep the sleeve in position during swaging. * Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

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