This document describes improvements to hammer-operated tools like punches and chisels. It discloses a tool with a gripping portion and an impact member made of hardened steel that is fitted into the gripping portion. This protects the tool from spreading or deforming under repeated hammer blows. It also describes a tube expander tool made from hexagonal tubing with one end shaped for gripping and the other fitted with an impact member of hardened steel.

1. * GB780163 (A)
Description: GB780163 (A) ? 1957-07-31
Improvements in punches, drifts, cold chisels and like hammer-operated tools
Description of GB780163 (A)
I, NORMAN STOTT, a British Subject, of
197A Whiteacre Road, Aston-under-Lyne, in the County of Lancaster, do
hereby declare the invention, for which I 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:-
A defect common to punches, drifts, cold chisels and similar
percussion tools as hitherto known is that, with the constant
hammering, the top end of the tool tends to spread and become
mis-shapen, even to an extent which causes the hammer to 1,5 glance
off it.
In order to overcome this defect it has been proposed to fit a
detachable cap of hard metal over the solid end of a tool, say by
screwing it on or driving it on to a conical end portion of the tool.
It has also been proposed to use a hollow steel holder drifted square
or oblong interiorly at each end to receive interchangeable cutters or
chisels of various shapes at one end and interchangeable loose heads
of different shapes, the heads being made of ordinary steel similarly
to the holder.
It is the object of the present invention to provide improved means
for overcoming or eliminating the said defect. The invention is
particularly useful as applied to tube expanders which, by means of a
hammer, are driven into the open end of a tube (e.g.
a copper tube) to enlarge its diameter so as to allow it to receive
the non-expanded end of a similar tube.
According to the invention, a tool of the class described has a large
part of its length of polygonal (e.g. hexagonal) cross section, as a
gripping portion, has a cylindrical opening at one end in which is
fitted the cylindricalu,, of an im act member of hard 780,163 or

2. toughened steel, such member extending out of said gripping portion,
to provide a hard striking face, and said gripping portion 45 being
formed either as a solid bar or as a drawn tube.
The invention also provides an improved tube expander or like tool
formed from hexagonal, octagonal or similar tubing, and 50 comprising
a gripping portion of that cross section, one end of the tube being
rolled or swaged to a circular cross section, with parts of such end
of two diameters, and the other end being fitted with the cylindrical
plug of an impact member of hard or toughened steel, the plug having a
head which overlies the adjacent end of the tube and provides a hard
striking face. The circular portions of the said one end will 60 have
a tapered or chamfered portion between them, to effect the expansion
of a tube when driven into it, and the end receiving the hardened plug
will preferably be rolled or swaged to a round cross section, 65 the
plug in that case having a smaller part to enter the tube and a part
of larger diameter to fit against the end of the tool.
Representative examples of the invention are illustrated in the
accompanying drawing, 70 wherein: Fig. 1 is a part sectional side view
of a punch or drift incorporating one form of the invention; Fig. la
is an end view of the same; 75 Fig. 2 is a similar view to Fig. 1 but
illustrating another form of the invention; Fig. 2a is an end view of
the same; and Figs. 3 and 4 illustrate two forms of tubeend expander
to which the invention has 80 been applied.
Referring to Fig. 1 a punch or drift is made from a length of
hexagonal bar stock and has a handle portion or gripping portion
PATENT SPEUFICAION Date of filing Complete Specification: Jan. 31,
1955.
Application Date: Jan. 29, 1954. No. 2677/54Complete Specification
Pub7ished: July 31, 1957.
Index at Acceptance:-Classes 61, L2B; and 83(4), Z.
International Classification:-B21d. B26b.
COMPLETE SPECIFICATION.
Improvements in Punches, Drifts, Cold Chisels and like Hammer-Operated
Tools.
1 and a working portion 2, the latter being formed for example by
turning in a lathe.
The upper end of the bar is drilled at 3 to receive a plug 4 of a
toughened steel which will withstand repeated hammer blows on its
outer face 5 without spreading. The outer edge of the plug 4 is
slightly bevelled, but this is not essential. The inner ends of the
hole 3 and plug 4 may be of the same shape mating with each other, for
example both pointed or both square, or they may be of different
shapes the end of the plug being square and the end of the hole being
pointed.

3. In Fig. 2 a similar tool is shown but the plug 4 is provided with a
head 6 which lies against the end of the handle portion 1.
This head 6 is shown as being of a hexagonal contour, agreeing with
the cross section of the handle portion 1, but it could be of circular
or other form and in any case could be larger or smaller in diameter
than the handle portion 1.
Referring now to Figs. 3 and 4, a tube expander is shown, of the kind
set forth in Patent Specification No. 648,652, for forcing into the
open end of a tube to expand it into a larger cross section. The
centre or handle portion differs in each case, but in both cases a
length of hexagonal tube 14 is formed to a round cross section at one
end to receive the round sectioned plug 15 of a hexagonal cap 16, the
cap permanently held therein and lying against the end of the tube.
At the other end the tube is formed to a round cross section at the
parts 17 and 18, one being larger than the other and there is a
tapered formation 19 between them.
At its extreme end 20, the tube wall may be flanged over internally to
form an end wall, preferably with an opening at its centre, The
non-hexagonal parts of the tool may be formed in any suitable manner,
for example by rolling andlor swaging.
Advantages of the invention are that a working end of reduced diameter
can be obtained without wasteful removal of metal, and a minimum
amount of high grade steel is required regardless of the actual bulk
of the tool.
The cores and plugs may be heat treated if necessary before being
fitted with the handles and this greatly reduces the amount of metal
requiring heat treatment.
Inner and outer parts may be secured together by pins passing through
them andy or by being welded together or otherwise and in any case the
outer parts may be "shrunk" on to the inner parts.
A further advantage of the invention, especially with tools such as
those shown in Figs. 3 and 4, is that the tools are not so heavy as
when they are of one-piece solid form.
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