An Improved Tool Coupling.
Year: 1894

page_text: Date of Application, 18th May, 1894-Accepted, 11th Aug.,
1894
An Improved Tool Coupling.
I, WILLIAM CHENEY BROWN, of South Manchester, in the County of Hartford
and State of Connecticut, one of the United States of America, Merchant, do
hereby declare the nature of my invention, and in what manner the same is
to be performed to be particularly described and ascertained in and by the
following statement:―
My invention relates to tool couplings in general, and it consists in certain
improvements, which are fully set forth in the following Specification, and shown in
the accompanying drawings, which form a part thereof.
More specifically my invention relates to tool couplings, which are used in
securing two parts of a tool together in a firm and practical manner and admit
of such tool being detached at pleasure, and a number of tools being so constructed
a common handle,
that they may be, by the formation of their shanks on
The coupling is necessarily in two separable parts; the shank of the tool has
formed on its end preferably a wedge or chisel shape, and on its outer circumference
near the end a thread is raised.
interchangeable.
The other portion of the coupling, which is usually attached to the handle, has a
hollow stem which projects from the handle; this stem is rotatable.
Within this hollow stem, which is threaded nearly its whole length, is an
adjustable bolt which is also threaded and has upon its lower end a depression, the
counter of that on the end of the tool shank.
In the drawings a wedge shape is shown, but this is merely selected for its
simplicity as any other shape would answer just as well so long as the parts were of
such a shape as to be inter-engaging.
The thread on the shank of the tool is of the same pitch as the thread on the
lower part of the stem.
The thread on the bolt and on the upper part of the hollow stem is smaller than
the thread on the shank and lower part of the stem.
The object in having two pitches to the threads in the stem is to cause a jam
between the two after a few turns.
In light tools the jam caused by the two threads turning unequally is quite
strong enough to maintain the tool in the coupling.
Where great pressure is brought to bear on the handle, however, it may turn
when the action is reversed, to obviate this difficulty a collar is threaded and sleeved
over the outside of the stem; this sleeve has a thumb screw passing through it, a
shoulder inside of the stem prevents the screw bolt from turning too far as it will
abut against the shoulder.
There is a perforation in the stem through which the thumb screw is adapted
to pass when the sleeve is screwed down in the position in Fig. 1. The coupling
bolt has also a recess upon one or more of its sides and when the thumb screw has
passed through the perforation on the stem its end engages in the recess on the
screw bolt; this prevents the bolt from turning when in position and coupled with
the shank of the tool..
In Figure 2 the coupling is shown in position ready for use.
arranged to be adapted for all classes of mechanics' tools especially.
The coupling is
In the drawings A is the handle of the tool; B is the shank of the tool.
B' is the shank of the screw bolt. C is the wedge shape formation on the shank
of tool, C is the socket in the screw bolt in which the wedge shape C couples;
D is the thread on outside of tool shank. D is the thread on inside of stem
having greatest pitch. E is the screw threaded coupling bolt. E' is the thread
on the inside of the stem having the lesser pitch. F is the stem or sleeve.

page_text: G is the recess on the coupling bolt. H is the thumb screw. I is the perforation
in the stem through which the thumb screw passes. K is the collar which
carries the thumb screw. Lis the shoulder at the inside of the stem formed by
a separate part fixed to the stem.
The operation of this invention is as follows: The screw bolt is screwed down
until in position shown in Fig. 3. The shank end of the tool with its wedge
shape end is inserted in the wedge shaped cut formed on the screw bolt, and
the bolt is now screwed up into the stem F as the jams of the cut on the end
of the bolt engage the wedge on the end of the shank, and as the pitch of the
thread is much greater than the pitch of the thread on the screw bolt a few turns
draw the shank up into the cut on the bolt and also jam the two in this position it
is ready for use.
As a reverse direction to the screw would loosen the shank from its seat, there is
a collar provided K, which carries a thumb screw; this collar is threaded over the
stem so that it may be threaded down to the point, where a recess is formed on the
coupling bolt; at this point it is set as shown in Fig. 1 and this prevents the tool
from leaving its seat in the jams C¹ of E.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is,.
1st. In a tool coupler the combination of the screw threaded coupling bolt E
operating in a threaded stem, and having a jaw C' formed upon it, and the tool
shank B having a formation upon its end adapted to engage the jaw of the screw
bolt for the purpose set forth.
2nd. The tool shank B having a formation upon its end adapted to engage a
reverse formation on a threaded bolt operating within a stem, the said shank having
a thread formed upon it of greater pitch than that on the bolt, in combination with
a hollow stem having a thread upon its interior corresponding with the thread on
the shank for the purpose set forth.
3rl. In a coupling device two members adapted to be joined at their ends by
means of screw threads and provided with formations that interlock when joined
by. rotating the parts simultaneously, the interlocking caused by the operation of
two threads of different pitch upon the two parts, for the purpose herein set forth.
4th. In a coupling device for tools two parts provided on their adjacent ends
with screw threads and engaging means which prevent the rotation of one part
independent of the other, the threads of each part extending in the same direction,
and the thread on one part having a larger pitch than that on the other, both parts
operating in a sleeve having threads upon it fitting the thread on the respective
parts for the purpose herein shown and described.
5th. The combination in a tool coupler of a threaded sleeve, a threaded bolt
operating in said sleeve, a tool shank having a thread formed upon it adapted
to also operate on the thread of said sleeve and a means provided on both
bolt and shank, whereby the rotation simultaneously of both parts within said
sleeve, compels an interengaging of said parts, as and for the purpose herein shown
and set forth.
6th. In a tool coupler the combination of the threaded sleeves F and K, bolt E,
recess G, thumb screw H, shauk B with thread D and union points C and C¹ as
herein shown and described.
7th. A coupling for mechanics' tools consisting of two parts adapted to thread in
a sleeve, in which the two ends of the parts interengage and are held in such position
by a combination of differentiated screw threads upon the parts, as herein shown and
described and for the purpose set forth.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.