Improvements in Pipe-wrenches.
Year: 1889

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by JOHN THOMAS HAWKINS, of No. 46, Harrison Street,
in the City of Taunton, County of Bristol, State of Massachusetts, United States
of America, Engineer.]
Improvements in Pipe-wrenches.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co. Patent Agents,
Southampton Buildings in the County of Middlesex 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 :—
«
The object of this invention is to provide, in the well-known solid alligator"
pipe-wrench, and adjustable stop or tooih, partially imbedded in or lying upon the
smooth jaw in such a way that the lateral strain brought upon the said stop shall
he transferred upon the jaw itself, and said adjustable stop or tooth be supported
by said jaw and applied to assist in the rotation of a pipe at the furthest point
possible from the point of contact of the serrated jaw with the pipe.
The instrument now well known as the solid "alligator" wrench consists of two
jaws so constructed as to form a V-shaped opening between them, one of the jaws
being toothed or serrated and the opposite one plain.. In the operation of such a
wrench upon a pipe or rod, the latter slides upon the smooth jaw until the teeth
or serrations on the opposite jaw take firm hold on the said pipe or rod. The
tendency is found to be, however, in such construction, to more or less crush a
pipe operated on, under considerable rotative strain, by the forcing of the pipe still
further up into the V-shaped opening. It has been proposed to obviate this tendency
by providing an adjustable screw stop, passing through the vertex of the angle
made by the inner surfaces of the two jaws. This latter construction is, however,
open to the objection that the stop is applied so near to the point of contact of
the serrated jaw with the pipe as to interfere with a firm hold being taken upon
the pipe by said serrations or teeth; and, if the wrench rotates upon the pipe after
contact of the screw stop, it operates to bring considerable transverse strain upon
said stop, and particularly when operating upon pipes of large diameter, at which
time the screw stop is protruded furthest into the angle of the jaws. In this con-
struction, also, the said stop cannot be made to perform the function of a tooth or
teeth without insuring transverse bending of the stop.
My invention, however, provides an adjustable stop lying in a recess formed in the
smooth jaw, or lying upon and supported by the smooth jaw, so that said jaw may
operate upon the pipe at the furthest point possible from the point of contact of the
serrated jaw therewith, merely as a stop, or be formed into a sharp tooth upon that
side; and thus to provide against crushing by obstructing the further entrance of the
pipe into the angle of the jaws after the serrated jaw has taken firm hold; and also to
assist in rotating the pipe by acting as an abutment or stop, or as a tooth, as may be
prefered.
In the accompanying drawings
Figure 1 illustrates, in side view, the invention applied to such a wrench, and
Figure 2 shows a side view of the jaw end of the wrench, with the point of the stop
screw pointed to serve merely as a stop, without any action as an opposite tooth.
Figure 3 illustrates a modification of the invention shown in the preceding Figures.
Figure 4 is an edge view of Figure 3; and
Figure 5 is a section taken through Figure 3 at the line B C.
In Figures 1 and 2 the number 1 indicates the body of the wrench; 2 the serrated
jaw; 3 the plain jaw; and 4 the stop-screw, threaded in its enlargement 5, formed
upon the wrench for purposes of strength. In Figure 1 the point of the stop-screw 4
is made square on the end so as to form a sharn corner to nenetrate the nine and act

page_text: as a nearly opposite tooth. In Figure 2 this point is tapered so as to act merely as a
sudden increase of angle of the jaws, to prevent further entrance of the pipe, which
latter is shown as a dotted circle in said figures.
In Figures 3, 4, 5, the several parts are indicated by reference numbers as
follows:
The number 1 indicates the body of the wrench, having formed upon it the smooth
jaw 2 and the serrated jaw 3, making with each other the proper angle. An adjusting-
screw 4, is threaded in the body of the wrench, the point of which impinges upon a
sliding-stop 5. The smooth jaw 2 is grooved at the sides, as at 6, and the sliding
stop 5 is formed to fit therein as shown in section, Figure 3. The sliding-stop 5 has
one or more engaging-edges formed upon it, 7 and 8, and is shown in one extreme
position in full lines and at the other extreme in dotted lines, Figure 3. The dotted
circles 9, 10, 11, 12, show the range, in size, of pipes which may be operated on. For
the largest pipe 9, the pipe is taken between the surfaces of the two jaws, and the
end-engaging-tooth-edge, 7, is used to prevent further entrance of the pipe into
the angle of the jaws and to assist in its rotation; and similarly for any smaller
size down to that shown by the dotted circle 11, in which the dotted sliding-
block 5 is shown impinging against the pipe by its end-engaging-tooth-edge 7.
For the next smaller size 10, the block is placed as in full lines, and the pipe
rests upon the forward part of the sliding-block, instead of on the jaw 2, and the
back engaging-edge 8 of the block 5 impinges against it; and similarly for any
smaller pipe than 10 down to that shown by the dotted circle 12.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondent I declare that what 1 claim is
First. A pipe-wrench having one serrated jaw and one unserrated or smooth
jaw, forming an acute angle with each other, and provided with an adjustable stop
for the pipe, operated upon and practically in line with the angle of said smooth jaw,
substantially as and for the purposes set forth.
Second. In a pipe-wrench constructed of a serrated or toothed jaw, and a smooth or
unserrated jaw, forming an acute angle with each other, the combination of a stop for
the pipe, sliding upon the smooth jaw, and an adjusting screw for regulating the position
of said sliding stop, substantially as set forth.
Third. In a pipe-wrench constructed with a serrated or toothed jaw and a smooth or
unserrated jaw, forming an acute angle with each other, in combination with a stop
sliding upon the smooth jaw, and having formed thereon tooth-edges, an adjusting
screw for regulating the position of said sliding stop, substantially as set forth.
Dated this 4th day of June 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.