A New or Improved Pipe Wrench.
Year: 1896

page_text: Date of Application, 29th Aug., 1896-Accepted, 10th Oct., 1898
[Communicated from
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United States of America, Engineer.]
A New or Improved Pipe Wrench.
I, ROBERT NORTON of North Elmham' in the County of Norfolk, Miller, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and' by the following
statement:-
This invention relates to a new or improved pipe wrench which has been
designed to afford a better grip and. to enable the wrench to be used with pipes
and the like having, different diameters.
My new or improved wrench is illustrated by the accompanying drawings
which represent the wrench in side elevation.
On the hoad of the wrench H there are formed the usual serrations or teeth for
gripping one side of the pipe, and at about right angles to these but nearer the
haudle a convenient number of gear teeth G. 1 prefer to use two such teeth, as
represented by the drawing, but any other convenient number may be employed.
In conjunction with this part of the wrench I employ an L-shaped jaw J, on the
upper inner face of which gripping teeth or serrations are formed, and on the
The jaw
lateral inner face, gear teeth y constructed to gear with the teeth G.
is held in contact with the wrench head by means of a strap or clip S which is
pivoted at s upon the head. The two ends of the strap S project to form lugs L
on the side of the wrench opposite to the lateral part of the jaw, in which lugs the
upper end of a connecting rod C is engaged, so that when the connecting rod is
moved longitudinally the strap will also be moved in one direction or the other around
its pivot s.
This motion of the strap will cause the jaw also to move in such a
manner that if the connecting rod be reciprocated the lateral member of the jaw
will rook upon the gear teeth G. This motion of the jaw brings the serrated part
of the jaw alternately nearer to and further away from the serrated part T. When
it approaches the serrated part T it grips the pipe as shown by Figure 2 and when
it is caused to recedo, the pipe is released.
A convenient method of reciprocating the connecting rod O is illustrated by the
drawing. The handle end of the connecting rod is connected to the angle of a bell
crank lever M which is fulcrumed at 1 on the opposite side of the handle. The
longitudinal member of this lever is parallel with the handle part N when the
wrench is closed, Figure 2, but stands at an angle to it when the wrench is opened,
as represented by Figure 1.
When the wrench is to be brought into use, the lever M and handle part N are gripped
by the hand, thus tending to force M nearer to the handle N. The consequent
movement of the connecting rod causes the jaw to approach the serrations T and to
grip the pipe. In turning the wrench, the pressure of the hand is exerted upon
the lever M thus ensuring a firm grip which increases with the power exerted.
Upon the lever M being released, the wrench may be at once removed from the
pipe.
It will be apparent that by gearing the jaw with the teeth on the side of the head
of the wrench, higher up or lower down the rack on the inside of the jaw, the
wrench may be adjusted for larger or smaller pipes. For this purpose the strap
may be connected with the head of the wrench by a screw pivot as indicated, so

page_text: that it may be removed to alter the gear as may be required. In general however
it will be found advantageous to make different sizes of wrenches for different
diameters of pipes, in which case it will suffice if there is only one gearing tooth
on the side of the head and two teeth on the inside of the jaw, but even then it will
be better-to have at least two teeth on the head and three on the jaw.
As shewn by the drawing Figure 2 illustrates the wrench when in use, the pipe
being shown at P. Figure 1 represents the wrench when out of use.
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 :-
1. In a pipe wrench, a gear tooth or gear teeth on the head of the wrench in
combination with an L-shaped jaw having corresponding teeth on its inner face, a
pivoted strap retaining the jaw in gear with the head of the wrench and means for
moving the strap upon its pivot, constructed and arranged substantially as hereinbefore
described and as illustrated by the accompanying drawing.
2. A pipe wrench constructed substantially as herein before described and as
illustrated by the accompanying drawings.
Dated this 27th day of AAD 1000
W. E. HEYS & SON,
Agents for the Applicant.