The universal motor can operate on either AC or DC power and is commonly used in portable power tools and small appliances. It has a series-connected rotor and stator. The commutator and brushes reverse the current in the armature coils as it rotates, allowing the motor to operate on both AC and DC power sources. The direction of rotation is independent of the power source polarity. Speed can be controlled by reducing the voltage applied to the motor.
Universal motors can operate on either AC or DC power. They have high starting torque because the armature and field windings are connected in series. Speed control of a universal motor is achieved by varying the terminal voltage, which changes the current and electromagnetic torque. The motor's angular velocity is determined by solving the differential equation for the electrical system, which depends on the induced back EMF. Back EMF is produced by the motion of the rotor in the magnetic field and opposes the applied voltage, with its magnitude proportional to speed. Varying the applied voltage allows control of the motor's speed and torque.
this ppt is made by me (harshid panchal),
guided by prof : Hitesh Manani,
we are from electrical engineering at gandhinagar institute of technology
https://harshidpanchalhp.wordpress.com/
harshidpanchalhp@gmail.com
This document provides an overview of DC motors, including their construction, principle of operation, types (series wound, shunt wound, compound wound), speed control methods, and applications in aircraft. The key points are:
- A DC motor consists of an armature mounted in bearings, stationary field coils, a commutator, and brushes. The motor operates by inducing a back EMF in the armature as it rotates through the magnetic field.
- Series wound motors have high starting torque but can overspeed without a load. Shunt wound motors have low starting torque but maintain constant speed under varying loads. Compound wound motors combine characteristics of both.
- Motor speed can be controlled by
To reverse the rotation, we need to swap the connections of either the field or armature winding, but not both. Swapping both connections does not change the direction of rotation.
THIS DOCUMENT MAINLY CONTAINS THE HOW TO MODLE DC SERVO MOTOR BY USING THE MATLAB SIMULINK AND HOW IT WILL BEHAVE IS SHOWN IN THE MATHEMATICAL EQUATIONS AND THE PLOTTINGS ARE ALSO KEPT IN THIS DOCUMENT SO BY THIS IT IS USEFUL TO STUDY THE CHARACTRISTICS OF A DC SERVO MOTOR
The document discusses AC series motors and universal motors. It provides the following key points:
1) A universal motor can operate on either AC or DC power sources. It has series-connected rotor and stator windings.
2) An AC series motor is electrically similar to a DC series motor but uses special construction materials to reduce losses from eddy currents.
3) Speed control of an AC series motor is similar to a DC series motor and can be achieved through armature resistance/reactance control, field flux control, or armature voltage control. Armature voltage control is commonly used for large motors.
The universal motor can operate on either AC or DC power and is commonly used in portable power tools and small appliances. It has a series-connected rotor and stator. The commutator and brushes reverse the current in the armature coils as it rotates, allowing the motor to operate on both AC and DC power sources. The direction of rotation is independent of the power source polarity. Speed can be controlled by reducing the voltage applied to the motor.
Universal motors can operate on either AC or DC power. They have high starting torque because the armature and field windings are connected in series. Speed control of a universal motor is achieved by varying the terminal voltage, which changes the current and electromagnetic torque. The motor's angular velocity is determined by solving the differential equation for the electrical system, which depends on the induced back EMF. Back EMF is produced by the motion of the rotor in the magnetic field and opposes the applied voltage, with its magnitude proportional to speed. Varying the applied voltage allows control of the motor's speed and torque.
this ppt is made by me (harshid panchal),
guided by prof : Hitesh Manani,
we are from electrical engineering at gandhinagar institute of technology
https://harshidpanchalhp.wordpress.com/
harshidpanchalhp@gmail.com
This document provides an overview of DC motors, including their construction, principle of operation, types (series wound, shunt wound, compound wound), speed control methods, and applications in aircraft. The key points are:
- A DC motor consists of an armature mounted in bearings, stationary field coils, a commutator, and brushes. The motor operates by inducing a back EMF in the armature as it rotates through the magnetic field.
- Series wound motors have high starting torque but can overspeed without a load. Shunt wound motors have low starting torque but maintain constant speed under varying loads. Compound wound motors combine characteristics of both.
- Motor speed can be controlled by
To reverse the rotation, we need to swap the connections of either the field or armature winding, but not both. Swapping both connections does not change the direction of rotation.
THIS DOCUMENT MAINLY CONTAINS THE HOW TO MODLE DC SERVO MOTOR BY USING THE MATLAB SIMULINK AND HOW IT WILL BEHAVE IS SHOWN IN THE MATHEMATICAL EQUATIONS AND THE PLOTTINGS ARE ALSO KEPT IN THIS DOCUMENT SO BY THIS IT IS USEFUL TO STUDY THE CHARACTRISTICS OF A DC SERVO MOTOR
The document discusses AC series motors and universal motors. It provides the following key points:
1) A universal motor can operate on either AC or DC power sources. It has series-connected rotor and stator windings.
2) An AC series motor is electrically similar to a DC series motor but uses special construction materials to reduce losses from eddy currents.
3) Speed control of an AC series motor is similar to a DC series motor and can be achieved through armature resistance/reactance control, field flux control, or armature voltage control. Armature voltage control is commonly used for large motors.
The document discusses the universal motor, which can operate on both AC and DC power. It has a series-wound construction similar to a DC motor but with laminated magnetic components to reduce eddy currents from AC power. Universal motors are commonly used in appliances like drills, fans, and blenders because they can function using both AC household power and portable DC batteries. The document covers the construction, working principle, characteristics, and common defects of universal motors.
The document discusses three methods for controlling the speed of a DC motor: 1) varying the armature circuit resistance, 2) varying the field flux, and 3) varying the terminal voltage using the Ward-Leonard method. It provides details on how each method works, including equations showing how speed is affected. The Ward-Leonard method uses a motor-generator set to convert AC power to DC power at a controlled voltage to regulate motor speed. Advantages and disadvantages of each method are also summarized.
Application of dc generator at railway coachjjasdxjz
this ppt will explain the basics about dc generator and also it will briefly explain the applications of dc generator at railway coach and its uses.so its very useful for engineering students
Motors use electromagnetic induction to convert electrical energy into mechanical energy. AC motors have a stationary stator and rotating rotor that interact via magnetic fields generated by alternating currents. DC motors consist of an armature winding and stator winding, with the armature acting as the rotor. Motor starters are used to control motor speed and current during starting to prevent damage. Common motor starters include magnetic, full-voltage, reversing, reduced-voltage, and solid-state starters. Reduced-voltage starters gradually apply voltage during starting for smoother acceleration.
- A Direct On Line (DOL) starter connects the motor directly to the power supply. It consists of fuses, an isolator, contactor, and overload protection. Pressing the start button energizes the contactor coil to close the contacts and start the motor.
- A reversing DOL starter uses two contactors to reverse the motor direction by swapping the phase connections. It has separate start buttons for forward and reverse operation.
- A star-delta starter reduces starting current by initially connecting the motor in star configuration before switching to delta. This allows the motor to start smoothly before applying full voltage once up to speed.
This document discusses different types of DC generators, including separately excited, self-excited, shunt, series, and compound generators. It describes the characteristics of shunt generators, including their open circuit characteristics curve and how terminal voltage is affected by load current and armature reaction. The document also defines terms like rated voltage, voltage regulation, residual voltage, and critical resistance. Sample problems are included to demonstrate how to calculate generator voltage based on field current, speed, and load.
The document describes the key characteristics of a DC generator, including:
1. The no-load saturation characteristic (E0/If) which shows the relationship between no-load generated EMF and field current at a fixed speed.
2. The internal or total characteristic (E/Ia) which gives the relationship between induced EMF and armature current, accounting for armature reaction.
3. The external characteristic (V/I) which gives the relationship between terminal voltage and load current, accounting for voltage drops from armature resistance.
This document discusses the power stages in DC generators and motors. It explains that in a DC generator, the input mechanical power minus losses equals the electrical power output, and the efficiencies can be calculated at each stage. A DC motor operates similarly but converts electrical power to mechanical power output. It also describes the basics of how DC motors work using Fleming's left hand rule, the production of back EMF, different types of DC motors, sources of losses in DC motors, and methods for testing DC machines.
This document discusses DC generators and motors. It begins by explaining how a rotating loop of wire in a magnetic field produces an alternating current (AC). It then describes how using split rings and brushes converts this to direct current (DC) in a generator. The key parts of a DC generator are identified as the stator, rotor and commutator. Expressions are given for the generated voltage in terms of machine parameters like speed, flux and number of turns. Different methods of field excitation like shunt, series and compound connections are explained. The buildup process of a self-excited shunt generator is described. External characteristics graphs of voltage versus current are shown for separately and shunt excited generators.
This document summarizes different types of excitation systems for alternators. It discusses the function of excitation systems to supply direct current to the field winding and control the voltage and reactive power of alternators. The three main types covered are DC excitation systems, AC excitation systems, and static excitation systems. DC excitation systems use two small DC generators as exciters but are not commonly used for large alternators now. AC excitation systems include brushless and rotating thyristor types and have advantages like eliminating brushes. Static excitation systems have no rotating parts, are suitable for medium and high capacity alternators, and have benefits like smaller size and no windage losses. The document concludes that the selection of an excitation system depends on factors like the altern
This document describes an experiment conducted on a self-excited DC shunt generator. The objectives were to investigate the relationship between output voltage and current of the generator when driven at a constant speed. The experiment involved connecting a DC generator and motor, and recording voltage and current values across various loads. The results showed a nearly linear relationship between output voltage and current, with voltage decreasing as current increased. Some inaccuracies may have been due to old equipment. In conclusion, the experiment demonstrated the relationship between output voltage and current of a self-excited DC shunt generator driven at a constant speed.
The document discusses starters used for DC shunt motors. A three-point starter connects the field directly to the line when the starting arm makes contact, placing full starting resistance in series with the armature. As the arm moves, resistance is cut out until all is removed. A four-point starter takes the hold-on coil out of the field circuit and connects it directly to the line through a protecting resistance, making the hold-on coil current independent of field adjustments. This allows the four-point starter to be used for variable speed control.
THIS IS A PROJECT DONE BY USING SMALL ELECTRONICS COMPONENTS AND BY DOING THIS WE CAN SEE THE FADING OF LED BY UP AND DOWN AND FOR THIS WE MADE REPORT IN A SPECIFIED WAY AND IN THIS IS WE SHOWN EVERY STEP BRIEFLY HOW TO DO THE PROJECT AND THE RESULTS ARE ALSO COMING AND THIS PROJECT IS USEFUL FOR MANY TO DO PROJECTS
This document discusses direct current (DC) motors and motor starters. It explains that DC motors draw a large starting current that can cause issues. Motor starters are used to gradually introduce voltage to reduce this starting current. The document then describes the components and operation of 3-point and 4-point motor starters, including how they introduce resistance to reduce starting current and use hold-on coils and overcurrent releases for protection. A 4-point starter is preferable when wide speed control is needed since its hold-on coil is independent of the field circuit.
The document discusses various braking methods for induction motors, including regenerative braking, plugging, and different types of dynamic braking. Regenerative braking occurs when the rotor speed exceeds synchronous speed, causing power to flow in the reverse direction. Plugging involves reversing the phase sequence of the supply to change operation from motoring to braking. Dynamic braking disconnects one phase of the supply or connects the motor to a DC supply, causing the motor to act as a generator and dissipate energy as heat.
Here are the answers to the questions on DC generator characteristics:
1. The external characteristic gives the relation between terminal voltage and load current.
2. The three most important characteristics or curves of a DC generator are: the no-load saturation characteristic (E0/If), internal or total characteristic (E/Ia), and external characteristic (V/I).
3. Critical speed of a shunt generator means the speed for which the given shunt field resistance represents critical resistance.
4. One condition necessary for the build-up of a self-excited shunt generator is that there must be some residual magnetism in the generator poles.
5. Some other factors which affect the voltage building of
This document discusses starters used for DC motors. It explains that starters are necessary to limit starting current and torque for DC motors. It describes two-point, three-point, and four-point starters. Two-point starters are used for DC series motors, while three-point starters help control current in shunt and compound DC motors. Four-point starters function similarly but add a terminal to allow operation above normal speeds without tripping. In conclusion, the document emphasizes that starters play an important role in protecting DC motors, and motors should not be operated without appropriate starters.
This document provides information on DC machines, including their construction and operation principles. It describes how a DC machine can operate as either a motor or a generator. The rotor has coils wound in slots with ends connected to segments of a commutator. Brushes pressed against the commutator switch the current direction in the coils to maintain rotation. In a motor, the interaction between the magnetic field and current in the rotor coils produces a torque. In a generator, rotation of the coils in the magnetic field induces a voltage that is transmitted through the commutator.
Сытник В. С. Основы расчета и анализа точности геодезических измерений в стро...Иван Иванов
В книге изложены вопросы теории и практики расчета, бценки
и анализа точности геодезических измерений, выполняемых при
возведении промышленных, жилых и общественных зданий й\цн-
женериых сооружений. На основе существующих в теории вероят^~—-
ностей
математической статистики и ошибок измерений рассмат
риваются методы расчета необходимой и достаточной точности гео
дезических измерений
применительно к определенным стадиям
строительно-монтажных работ и конструктивным решениям зданий
и сооружений. Значительное внимание уделено анализу точности
результатов геодезических измерений
The document discusses the universal motor, which can operate on both AC and DC power. It has a series-wound construction similar to a DC motor but with laminated magnetic components to reduce eddy currents from AC power. Universal motors are commonly used in appliances like drills, fans, and blenders because they can function using both AC household power and portable DC batteries. The document covers the construction, working principle, characteristics, and common defects of universal motors.
The document discusses three methods for controlling the speed of a DC motor: 1) varying the armature circuit resistance, 2) varying the field flux, and 3) varying the terminal voltage using the Ward-Leonard method. It provides details on how each method works, including equations showing how speed is affected. The Ward-Leonard method uses a motor-generator set to convert AC power to DC power at a controlled voltage to regulate motor speed. Advantages and disadvantages of each method are also summarized.
Application of dc generator at railway coachjjasdxjz
this ppt will explain the basics about dc generator and also it will briefly explain the applications of dc generator at railway coach and its uses.so its very useful for engineering students
Motors use electromagnetic induction to convert electrical energy into mechanical energy. AC motors have a stationary stator and rotating rotor that interact via magnetic fields generated by alternating currents. DC motors consist of an armature winding and stator winding, with the armature acting as the rotor. Motor starters are used to control motor speed and current during starting to prevent damage. Common motor starters include magnetic, full-voltage, reversing, reduced-voltage, and solid-state starters. Reduced-voltage starters gradually apply voltage during starting for smoother acceleration.
- A Direct On Line (DOL) starter connects the motor directly to the power supply. It consists of fuses, an isolator, contactor, and overload protection. Pressing the start button energizes the contactor coil to close the contacts and start the motor.
- A reversing DOL starter uses two contactors to reverse the motor direction by swapping the phase connections. It has separate start buttons for forward and reverse operation.
- A star-delta starter reduces starting current by initially connecting the motor in star configuration before switching to delta. This allows the motor to start smoothly before applying full voltage once up to speed.
This document discusses different types of DC generators, including separately excited, self-excited, shunt, series, and compound generators. It describes the characteristics of shunt generators, including their open circuit characteristics curve and how terminal voltage is affected by load current and armature reaction. The document also defines terms like rated voltage, voltage regulation, residual voltage, and critical resistance. Sample problems are included to demonstrate how to calculate generator voltage based on field current, speed, and load.
The document describes the key characteristics of a DC generator, including:
1. The no-load saturation characteristic (E0/If) which shows the relationship between no-load generated EMF and field current at a fixed speed.
2. The internal or total characteristic (E/Ia) which gives the relationship between induced EMF and armature current, accounting for armature reaction.
3. The external characteristic (V/I) which gives the relationship between terminal voltage and load current, accounting for voltage drops from armature resistance.
This document discusses the power stages in DC generators and motors. It explains that in a DC generator, the input mechanical power minus losses equals the electrical power output, and the efficiencies can be calculated at each stage. A DC motor operates similarly but converts electrical power to mechanical power output. It also describes the basics of how DC motors work using Fleming's left hand rule, the production of back EMF, different types of DC motors, sources of losses in DC motors, and methods for testing DC machines.
This document discusses DC generators and motors. It begins by explaining how a rotating loop of wire in a magnetic field produces an alternating current (AC). It then describes how using split rings and brushes converts this to direct current (DC) in a generator. The key parts of a DC generator are identified as the stator, rotor and commutator. Expressions are given for the generated voltage in terms of machine parameters like speed, flux and number of turns. Different methods of field excitation like shunt, series and compound connections are explained. The buildup process of a self-excited shunt generator is described. External characteristics graphs of voltage versus current are shown for separately and shunt excited generators.
This document summarizes different types of excitation systems for alternators. It discusses the function of excitation systems to supply direct current to the field winding and control the voltage and reactive power of alternators. The three main types covered are DC excitation systems, AC excitation systems, and static excitation systems. DC excitation systems use two small DC generators as exciters but are not commonly used for large alternators now. AC excitation systems include brushless and rotating thyristor types and have advantages like eliminating brushes. Static excitation systems have no rotating parts, are suitable for medium and high capacity alternators, and have benefits like smaller size and no windage losses. The document concludes that the selection of an excitation system depends on factors like the altern
This document describes an experiment conducted on a self-excited DC shunt generator. The objectives were to investigate the relationship between output voltage and current of the generator when driven at a constant speed. The experiment involved connecting a DC generator and motor, and recording voltage and current values across various loads. The results showed a nearly linear relationship between output voltage and current, with voltage decreasing as current increased. Some inaccuracies may have been due to old equipment. In conclusion, the experiment demonstrated the relationship between output voltage and current of a self-excited DC shunt generator driven at a constant speed.
The document discusses starters used for DC shunt motors. A three-point starter connects the field directly to the line when the starting arm makes contact, placing full starting resistance in series with the armature. As the arm moves, resistance is cut out until all is removed. A four-point starter takes the hold-on coil out of the field circuit and connects it directly to the line through a protecting resistance, making the hold-on coil current independent of field adjustments. This allows the four-point starter to be used for variable speed control.
THIS IS A PROJECT DONE BY USING SMALL ELECTRONICS COMPONENTS AND BY DOING THIS WE CAN SEE THE FADING OF LED BY UP AND DOWN AND FOR THIS WE MADE REPORT IN A SPECIFIED WAY AND IN THIS IS WE SHOWN EVERY STEP BRIEFLY HOW TO DO THE PROJECT AND THE RESULTS ARE ALSO COMING AND THIS PROJECT IS USEFUL FOR MANY TO DO PROJECTS
This document discusses direct current (DC) motors and motor starters. It explains that DC motors draw a large starting current that can cause issues. Motor starters are used to gradually introduce voltage to reduce this starting current. The document then describes the components and operation of 3-point and 4-point motor starters, including how they introduce resistance to reduce starting current and use hold-on coils and overcurrent releases for protection. A 4-point starter is preferable when wide speed control is needed since its hold-on coil is independent of the field circuit.
The document discusses various braking methods for induction motors, including regenerative braking, plugging, and different types of dynamic braking. Regenerative braking occurs when the rotor speed exceeds synchronous speed, causing power to flow in the reverse direction. Plugging involves reversing the phase sequence of the supply to change operation from motoring to braking. Dynamic braking disconnects one phase of the supply or connects the motor to a DC supply, causing the motor to act as a generator and dissipate energy as heat.
Here are the answers to the questions on DC generator characteristics:
1. The external characteristic gives the relation between terminal voltage and load current.
2. The three most important characteristics or curves of a DC generator are: the no-load saturation characteristic (E0/If), internal or total characteristic (E/Ia), and external characteristic (V/I).
3. Critical speed of a shunt generator means the speed for which the given shunt field resistance represents critical resistance.
4. One condition necessary for the build-up of a self-excited shunt generator is that there must be some residual magnetism in the generator poles.
5. Some other factors which affect the voltage building of
This document discusses starters used for DC motors. It explains that starters are necessary to limit starting current and torque for DC motors. It describes two-point, three-point, and four-point starters. Two-point starters are used for DC series motors, while three-point starters help control current in shunt and compound DC motors. Four-point starters function similarly but add a terminal to allow operation above normal speeds without tripping. In conclusion, the document emphasizes that starters play an important role in protecting DC motors, and motors should not be operated without appropriate starters.
This document provides information on DC machines, including their construction and operation principles. It describes how a DC machine can operate as either a motor or a generator. The rotor has coils wound in slots with ends connected to segments of a commutator. Brushes pressed against the commutator switch the current direction in the coils to maintain rotation. In a motor, the interaction between the magnetic field and current in the rotor coils produces a torque. In a generator, rotation of the coils in the magnetic field induces a voltage that is transmitted through the commutator.
Сытник В. С. Основы расчета и анализа точности геодезических измерений в стро...Иван Иванов
В книге изложены вопросы теории и практики расчета, бценки
и анализа точности геодезических измерений, выполняемых при
возведении промышленных, жилых и общественных зданий й\цн-
женериых сооружений. На основе существующих в теории вероят^~—-
ностей
математической статистики и ошибок измерений рассмат
риваются методы расчета необходимой и достаточной точности гео
дезических измерений
применительно к определенным стадиям
строительно-монтажных работ и конструктивным решениям зданий
и сооружений. Значительное внимание уделено анализу точности
результатов геодезических измерений
Poialkova v.m. -_lifter-akademiia_(2007)Иван Иванов
The document is illegible as it contains random characters and symbols with no discernible words, sentences or meaning. It appears to be gibberish with no real information that can be summarized.
This document provides an introduction to a master's thesis that analyzes the legal and commercial issues in EU-Russia relations in the context of sanctions policy. It outlines the goals and structure of the thesis. The thesis will examine EU-Russia relations before and after sanctions were imposed in 2014 over Ukraine, the legal framework around the sanctions, and their impact on trade. It will also explore ways to optimize EU-Russia relations going forward. The introduction establishes that relations between the EU and Russia are an ongoing issue that significantly impacts international politics and economics.
Заковряшин А. И. Конструирование РЭА с учетом особенностей эксплуатацииИван Иванов
Показана роль конструкторского проектирования в обеспечении эффективности технического обслуживания РЭА по фактическому состоянию. В книге
взаимосвязанно решаются вопросы обеспечения ремонто- и контролепригодности
при конструировании РЭА. Ремонтопригодность рассматривается лак решающи”
фактор обеспечения эффективности применения аппаратуры. Область значений
конструктивных показателей РЭА определяется как результат решения задачи
оптимизации заданного качества функционирования.
The document provides guidance for directors of music in senior high schools on producing effective musical programs. It discusses various types of programs, considerations for program building such as attention, contrast and continuity. Organization, administration, publicity, programs/tickets, staging, lighting, costuming and other elements are covered. Experimental research was conducted, including visits to Radio City Music Hall and small theaters, to study professional practices.
1) Adolph W. Berkner of Cayuga, North Dakota invented an improved elevator bucket design.
2) Berkner's elevator bucket has a yieldingly supported bottom plate that can open under excessive weight to prevent overloading, and automatically closes when the weight reaches a predetermined amount to deliver accurate amounts.
3) The bottom plate is flexibly supported by a leather or metal strip attached to the top edge and backed by a metal strip, and is held closed by an arcuate leaf spring.
This document describes a radio navigation system that provides continuous indications of bearing and distance from a transmitter beacon to a receiver. It utilizes a single transmitter and receiver at the beacon location and a transmitter and receiver at the mobile location. The pulsed output of the distance measuring beacon is amplitude modulated with fundamental and harmonic bearing signals. At the mobile receiver, the distance is obtained from the timing of distance measuring pulses while the bearing is obtained by comparing the phase of the envelope wave components and reference signals.
This document describes a process for producing hydrocarbon drying oils through the polymerization of butadiene and styrene monomers in the presence of sodium catalyst. It discusses conducting the reaction in a reactor, then treating the product solution with an organic acid to convert the sodium into a filterable salt. The process aims to improve upon large-scale production by continuously feeding reagents to a reactor while removing the polymerized product, and pre-treating make-up materials to improve reaction efficiency.
This document describes improvements to a carbonating apparatus for producing aerated water. It details a conventional carbonator design and issues with maintaining proper carbonation levels and water temperature. The invention aims to address these issues by wrapping the carbonating chamber in helical coils of pipes, with one pipe carrying water and the other a refrigerant. This design cools the chamber directly to maintain carbonation levels while reducing operating pressures and refrigeration needs.
1. * GB780121 (A)
Description: GB780121 (A) ? 1957-07-31
Improvements in and relating to apparatus for cutting and working
electrically conductive materials by electro-erosion or electrolysis
Description of GB780121 (A)
A high quality text as facsimile in your desired language may be available
amongst the following family members:
BE522513 (A) DE1660861 (U)
BE522513 (A) DE1660861 (U) less
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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.
PATENT SPECIFICATION
... Inventor: GREGORY FEFER 7 [0ffiS 7 Date of filing Complete
Specification: Oct. 8, 1953.
-g Application Date: Sept. 3, 1952. No. 22173/52.
Complete Specification Published: July 31, 1957.
Index at acceptance:-Classes 41, A(2C4X: 2C5: 5); and 83(4), V4.
International Classification:-B23p. C23b.
COMPLETE SPECIFICATION
Improvements in and relating to Apparatus for Cutting and Working
Electrically Conductive Materials by ElectroErosion or Electrolysis
We, SPARCATRON LIMITED, a Body Corporate duly organised under the Laws
of Great Britain, of Abbey Yard, Bath in the County of Somerset, 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:-
2. This invention relates to apparatus for working materials and more
especially, though not exclusively, to apparatus for cutting or
working electrically conductive tmaterials more especially hard metals
such as metal carbides, tool steels and stainless steels
electrolytically or by means of electric spark discharges as described
in British Patent Specification No.
637,872.
In the method described in Specification No.
637,872 the workpiece or material to be worked or bored is connected
to the positive pole of a direct current supply, the negative pole
whereof is the electrode and oscillatory spark discharge conditions
are created between the workpiece and the electrode at the location to
be worked or bored while such location is constantly bathed in a
di-electric or other fluid for the dispersal of the particles of
swartf and at the same time to prevent undue rise in temperature at
the working or boring location.
It is an object of the present invention to provide an improved
apparatus including automatic means for adjustment of the electrode
which means can readily be overridden when manual control is desired.
According to the present invention the electrode is secured to a
longitudinally slidable rack member which is normally engaged by a
pinion adapted to be power driven to adjust the position of the
electrode in relation to a workpiece, means being provided for moving
such pinion out of engagement with the rack when it is desired to
adjust the latter manually, e.g. when making theinitial adjustment of
dhe electrode in relation to a workpiece prior to a cutting or
working."peration.
[Price 3s. 6d.] Preferably the pinion is carried, with appropriate
reduction gearing and a small motor, by a housing which is rotatable
about an axis parallel to the rack, positive or resilient catch or
holding means being provided normally to maintain the pinion in mesh
with the rack.
In a preferred embodiment applied to a vertical electrode for
electrical boring or Icutting, the electrode is carried by a vertical
rack member slidably mounted in an arm or bridge fixed above a work
bench. The upper end of the rack projects above the arm. or bridge and
mounts an appropriate handle for manual adjustments.
A pinion normally engages the rack, such pinion having a horizontal
shaft driven, through reduction gearing, by a small electric motor.
The motor is automatically energised to the extent required to
maintain a constant air or spark gap, between the electrode and
workpiece in spite of consumption of electrode material.
The pinion, reduction gear and motor are all mounted on an inner frame
or housing which is pivotally carried in an outer housing forming part
3. of the arm or bridge structure.
The pivotal axis is vertical and the pivots are constituted by a pair
of adjustable points or needles screwed into the outer housing from
above and below to engage corresponding recesses in the inner frame.
A handle projects from the inner frame through a slot in the outer
housing and permits manual disengagement of the pinion from the rack,
which pinion normally is maintained in engagement with the rack by a
toil spring mtounted in tension between the outer housing and a
portion of the inner frame remote from the pivots.
In a modification of the above embodiment the motor, and it may be
also the reduotion gear, are mounted in a fixed position,
disengagement of the pinion being obtained by the tilting of its
shaft.
The accompanying drawings illustrate by A-- -;. -,' ' 780,121 2
780,121 way of example the preferred embodiment of the invention, and
in the drawings:Figure 1 is a vertical section of the device and
Figure 2 is a horizontal sectional view.
Figure 3 is a perspective view, with certain parts broken away, of the
device.
The electrode 20 is mounted on or connected to, with the aid of a
chuck 1, a racked bar or rod which is displaceable axially in a head 3
of a casing or housing 4. The electrode is furthermore connected by a
cable 25 to the negative pole of the source of working current (not
shown) supplying the spark discharge energy.
The positive pole of this source of working current is connected by a
cable 24 to the workpiece 22 through the medium of a conductor base 21
on which (Figure 3) the workpiece 22 is secured, said base resting at
the bottom of a bath 23 of non-conducting material equipped with an
overflow 26 and a drain or discharge 27 for a bathing fluid, which
lcan be supplied through a pipe 5 connected to the electrodecarrier
chuck 1.
The rack 2 is in engagement with a toothed pinion 6 which is driven by
an electric motor 7 through the medium of a speed reducing gear for
regulating the position of the electrode.
The shaft of the motor 7 drives a worm and worm wheel 8 which, by
means of a second worm and worm wheel 9 in turn drives the toothed
pinion 6.
The electric motor 7, the speed reducing gear 8, 9 and the shaft
bearing the toothed pinion 6 are mounted in an inner casing or housing
10 which is surrounded by the outer housing or casing 4, and mounted
so as to be movable in the latter around an axis parallel with the
racked bar or rod, this axis being formed by the pivots 11 screwed
into the outer housing or casing 4. On one side of the balancing
pivots 11 there is provided a coil spring 12 fixed at one end to the
4. outer housing or casing 4 and! at the other end to the inner housing
or casing 10, and this spring 12 urges the inner housing or casing 10
to swing on the pivots 11 in such a manner that pinion 6 is held in
mesh with the rack. To the inner housing or casing is fixed a handle
13 extending outwards through a slot 17 in the external housing or
casing 4, which makes it possible to swing the housing or casing 10
against the action of the spring 12 in such a manner that the toothed
pinion 6 is brought out of mesh with the rack 2. The racked bar or
rod, and the electrode connected thereto, can then be raised or
lowered by means of a handle 14 located at the upper end of the racked
bar or rod. The outer housing or casing 4 is provided with a sleeve 15
by means of which the whole device can be mounted on a rod, bar or
similar part of a machine.
16 represents the terminal block for current to the motor 7 which does
not operate when the working electrode occupies the correct position
in relation to the workpiece. If however the working electrode should
depart from the normal position, by means of an auxiliary circuit (not
shown) the motor 7 is rotated in one or the other direction and thus,
through the medium of 'the reduction gear and the rack, the working
electrode connected thereto is displaced in the required direction
until it is the desired distance from the workpiece.
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![* GB780121 (A)
Description: GB780121 (A) ? 1957-07-31
Improvements in and relating to apparatus for cutting and working
electrically conductive materials by electro-erosion or electrolysis
Description of GB780121 (A)
A high quality text as facsimile in your desired language may be available
amongst the following family members:
BE522513 (A) DE1660861 (U)
BE522513 (A) DE1660861 (U) less
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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.
PATENT SPECIFICATION
... Inventor: GREGORY FEFER 7 [0ffiS 7 Date of filing Complete
Specification: Oct. 8, 1953.
-g Application Date: Sept. 3, 1952. No. 22173/52.
Complete Specification Published: July 31, 1957.
Index at acceptance:-Classes 41, A(2C4X: 2C5: 5); and 83(4), V4.
International Classification:-B23p. C23b.
COMPLETE SPECIFICATION
Improvements in and relating to Apparatus for Cutting and Working
Electrically Conductive Materials by ElectroErosion or Electrolysis
We, SPARCATRON LIMITED, a Body Corporate duly organised under the Laws
of Great Britain, of Abbey Yard, Bath in the County of Somerset, 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:-](https://image.slidesharecdn.com/vgppyjtussufnc6tygnx-signature-04a9b2118fd45631bc78c881ec932a3e09a8557a2c01c89890c690eff6d9bb6f-poli-151225202707-714150/85/780121-1-320.jpg)
![This invention relates to apparatus for working materials and more
especially, though not exclusively, to apparatus for cutting or
working electrically conductive tmaterials more especially hard metals
such as metal carbides, tool steels and stainless steels
electrolytically or by means of electric spark discharges as described
in British Patent Specification No.
637,872.
In the method described in Specification No.
637,872 the workpiece or material to be worked or bored is connected
to the positive pole of a direct current supply, the negative pole
whereof is the electrode and oscillatory spark discharge conditions
are created between the workpiece and the electrode at the location to
be worked or bored while such location is constantly bathed in a
di-electric or other fluid for the dispersal of the particles of
swartf and at the same time to prevent undue rise in temperature at
the working or boring location.
It is an object of the present invention to provide an improved
apparatus including automatic means for adjustment of the electrode
which means can readily be overridden when manual control is desired.
According to the present invention the electrode is secured to a
longitudinally slidable rack member which is normally engaged by a
pinion adapted to be power driven to adjust the position of the
electrode in relation to a workpiece, means being provided for moving
such pinion out of engagement with the rack when it is desired to
adjust the latter manually, e.g. when making theinitial adjustment of
dhe electrode in relation to a workpiece prior to a cutting or
working."peration.
[Price 3s. 6d.] Preferably the pinion is carried, with appropriate
reduction gearing and a small motor, by a housing which is rotatable
about an axis parallel to the rack, positive or resilient catch or
holding means being provided normally to maintain the pinion in mesh
with the rack.
In a preferred embodiment applied to a vertical electrode for
electrical boring or Icutting, the electrode is carried by a vertical
rack member slidably mounted in an arm or bridge fixed above a work
bench. The upper end of the rack projects above the arm. or bridge and
mounts an appropriate handle for manual adjustments.
A pinion normally engages the rack, such pinion having a horizontal
shaft driven, through reduction gearing, by a small electric motor.
The motor is automatically energised to the extent required to
maintain a constant air or spark gap, between the electrode and
workpiece in spite of consumption of electrode material.
The pinion, reduction gear and motor are all mounted on an inner frame
or housing which is pivotally carried in an outer housing forming part](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)