IMPROVEMENTS IN PIPE WRENCHES
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
W. Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents, for an Invention of IMPROVEMENTS IN PIPE
WRENCHES communicated to him from abroad by James L Taylor of
Ishpeming in the County of Marquette and State of Michigan, United States
of America
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 16th October 1883.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents
"IMPROVEMENTS IN PIPE WRENCHES" [communicated to him from abroad by
James L Taylor of Ishpeming in the County of Marquette and State of Michigan,
United States of America]
This Invention relates to an improvement upon that class of pipe wrenches in
which a screw threaded Shank or handle has combined with it a serrated head on
the working end of said shank, a nut on the screw threaded portion thereof and a
fork serrated curved or bent jaw pivoted to said nut.
The outer or working end of the handle or shank portion is formed or fitted
with a fixed head, that is or may be of square form at its base where it joins the
screw threaded shank but which is of reduced tapering construction on two of its
opposite sides, which are serrated. This head constitutes what may be termed the
fixed jaw of the wrench and by being serrated on opposite sides it is made
reversible for each half turn of the handle, and, if desired, its opposite serrated
sides may be at different angles to suit different kinds of work. This reversible
provision of the head or fixed jaw, gives a more varied gripping surface and
consequently reduces wear. Furthermore, the serrated surfaces of said head are
concave in the direction of the length of the head thereby giving a better hold or
grip than if the same were convex. The sloping configuration of these surfaces,
should be such as to adapt said surfaces to the largest pipe the wrench is
designed for.

page_text: The nut which is a long one, has two of its opposite sides flatened to form
bearings for the forked ends, of the swinging jaw, which are pivoted to opposite
sides of the nut. Said forked end portions are made diverging towards the nut
thus giving an increased width for the swinging jaw at its bearing, and allowing of
a stouter nut and thicker or stouter shank being used. The remaining portion of
the swinging jaw, which narrows towards its outer end, should be of corresponding
width, or thereabouts, with the fixed head or jaw of the Shank. This portion may
may be of hook form and is serrated internally on its concave face which may be
of a quarter of a circle more or less in length to give a firm and steady grip on the
pipe.
Instead of the swinging jaw being of curved hook shape at its outer or gripping
end, it may be of angular or V form, so as to present two serrated angular gripping
surfaces, alightly curved where they meet each other and join the remaining portion
of the jaw.
When the jaw is thus constructed the wrench will have three bearing surfaces on
the pipe to which it may be applied.
This jaw may have a rib along the back of it to strengthen it without adding
materially to its weight, said rib being divided at the forked portions to extend
along the backs thereof.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Patent Office on the 7th April
1884.
"
ALEXANDER MELVILLE CLARK, of the firm of A. M. and W. Clark of 53 Chancery
Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents.
"IMPROVEMENTS IN PIPE WRENCHES' A communication to me from abroad by
James L. Taylor, of Ishpeming, in the County of Marquette and State of Michigan,
United States of America
This invention relates to an improvement upon that class of pipe wrenches in
which a screw threaded shank or handle has combined with it a serrated head on
the working end of said shank, a nut on the screw threaded portion thereof and a
forked serrated curved or bent jaw pivoted to said nut.
Figure 1 represents a partly sectional longitudinal view of a pipe wrench
embodying this Invention. Figure 2 is a (partly broken) similar view of the same
in a plane at right angles to figure 1 of the drawings and Figure 3 is an edge view
of a modified construction of the swinging jaw. Similar letters of reference indicate
corresponding parts in all the figures.
Referring in the first instance to figures 1 and 2 of the drawing A is the metal
shank fitted with a wooden handle holding part or sleeve A¹. The metal shank A
is of circular form in its transverse section and of increased diameter where a screw
thread b is formed upon it to enable the nut B to be passed onto it from the tang
end of the shank before the wooden handle A¹ is applied and to give the shank
increased strength. The outer or working end of the shank A is formed or fitted
with a fixed head C, that is or may be of square form at its base where it joins the
screw threaded shank band which has its two opposite sides co inclined towards
one another and slightly concave and transversely serrated as shown the other two
sides c¹ being parallel. This head C constitutes what may be termed the fixed jaw
of the wrench and by being serrated on opposite sides it is made reversible at each
half turn of the handle, and, if desired, its opposite serrated sides may be at
different angles to suit different kinds of work. This reversible provision of the
head or fixed jaw, that is the jaw in solid connection with the shank, gives a more
varied gripping surface and consequently reduces wear. Furthermore, the serrated
surfaces oc of said head being concave in the direction of the length of the head
thereby obtain a better hold or grip than if they were convex.
The sloping
configuration of these surfaces c c should be such as to adapt said surfaces to the
largest pipe the wrench is designed for.
The screw threaded portion b of the shank should be twice the length or
thereabouts of the nut B, or otherwise sufficiently long to allow of the head C
moving outwards to close with the swinging jaw D. The nut B which is a long
one has two of its opposite sides flattened to form bearings for the forked ends d d,
of the swinging jaw D which are pivoted at e to the nut. Said forked end
portions d, d, are made diverging to embrace the nut between them, thus giving an
increased width for the swinging jaw at its bearing and allowing of a sufficiently
stout nut and a sufficiently thick and strong shank being used to resist ordinary
strain. The remaining portion of the swinging jaw D, which narrows towards its
outer end, should be of corresponding width, or thereabouts, with the fixed head or
jaw C. This portion as illustrated in figures 1 and 2 is of hook form and is serrated
on its concave face which may be of a quarter of a circle more or less in length to
give a firm and steady grip on the pipe P as the wrench is worked in the direction
of the arrow . When worked in a reverse direction it releases its grip, as in the
case of other pipe wrenches hereinbefore referred to,

page_text: Instead of the swinging jaw D being of curved hook shape at its outer or
gripping end, it may be of angular or V form as represented in figure 3, so as to
present two serrated angular gripping surfaces, slightly curved where they meet
each other and join the remaining portion of the jaw. When the jaw D is thus
constructed, the wrench will have three bearing surfaces on the pipe to which it
may be applied.
The jaw D may have a rib g along its back to strengthen it without adding
materially to its weight, said rib being divided at the forked portions d d to extend
along the backs thereof.
The adjustment of the wrench is effected by turning its handle, or by turning the
nut with its attached jaw on the handle.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is:
1st In a wrench the fast head or jaw C, having opposite serrated sides c c in
combination with a concave swinging jaw D, forked and serrated, substantially as
and for the purposes specified.
2nd The combination with the shank A having a screw thread 6 on it, of the fast
head or jaw C, having opposite concave serrated sides c c converging towards one
another, the nut B, and the forked jaw D, pivoted to said nut, essentially as shown
and described.
In witness whereof I the said Alexander Melville Clark, have hereunto set my
hand and seal this Seventh day of April A.D. 1884.