Improvements in Pipe Wrenches.
Year: 1892

page_text: Date of Application, 4th Oct., 1892--Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
Improvements in Pipe Wrenches.
We, J. W. ALLEN, of Richford, Tioga County, State of New York, and
DUNCAN MCLACHLAN, of Groton, Tompkins County, State of New York, both
Gentlemen, 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 :-
Our invention relates to that class of pipe wrenches in which an adjustable chain
partly encircles the pipe, and in conjunction with a toothed dog grips the pipe.
Our object is to produce a pipe wrench in which the chain is adjustable, and in
which the grip or bite of the toothed dog is variable, said dog being pivotally
mounted or hinged to a sleeve, which is threaded to permit the handle to be
screwed in so as to bear against the back of the dog, and thereby force the teeth
more or less into the pipe, and also to hold them in such close contact therewith
that the eccentric throw of said dog will cause them to bite more thoroughly into
the pipe; and in which the toothed portion of the dog is removable from the body
thereof, and in which the slack of the chain can be taken up by adjusting and
rotating the bandle.
Our invention consists in the several novel features of construction and operation
hereinafter described and which are specifically set forth in the claims hereunto
annexed.
It is constructed as follows, reference being had to the accompanying drawings,
in which
Fig. 1, is an isometrical elevation of the wrench applied to a pipe.
Fig. 2, is a side and partially longitudinal sectional elevation of the wrench, part
of the chain being broken out.
Fig. 3, is a front elevation of the gripping dog, detached.
Fig. 4, is a rear elevation of the same.
A, is the handle or lever, threaded adjacent to its front end, and screwed into
the interiorly threaded sleeve B, and the front end of said lever is rounded off
substantially as shown at a.
The sleeve provided with an arm b, with a lug or lugs c to which one end of
the chain d is secured and on the opposite side with prongs, forks e to which the
free end of the chain is detachably connected.
Upon the arm b the dog D is pivotally mounted or hinged, its front face being
recessed or mortised so as to permit the toothed segment h to be slid in edgewise,
so that when one segment becomes worn, it can be readily replaced by another.
its free end is slotted as at h¹ when desired to adapt it to engage with a link of
the chain, and operate as a chain tightener, through the eccentric throw of the
dog, when operated.
The rear face of the dog is recessed or concaved, as at k, to receive and create a
bearing for the end of the handle.
When the end of the dog is not slotted, or is not adapted to positively engage
with the chain, the chain can be tightened around the pipe, by screwing the handle
in and pushing the dog forward and thereby forcing the pipe into the bight of the
chain, until all of the slack is taken
up.
In Fig. 2 we show the sleeve provided with an internal shoulder m at the front
end of the thread, which limits the movement of the handle in the sleeve, but it
is evident that this shoulder can be omitted when it is desired to give the handle
more movement.
In the same figure we also show the dog head as provided with a shoulder n
which is adapted to engage with the sleeve, and prevent the dog from falling over,

page_text: but it is evident that this shoulder may be varied in size or form, or omitted
entirely; but when it is used, the dog is always in position ready for use, and
requires no manipulation to place it in proper position.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. In a pipe wrench, the combination with the internally threaded sleeve, the
dog pivoted upon an arm extending from the outer end thereof, and the chain
connected thereto, of a screw threaded handle inserted through the sleeve and
engaging with the dog.
2. In a pipe wrench, the combination with the internally threaded sleeve, the
screw threaded handle inserted therein, and the chain connected to the sleeve, of
the toothed dog pivoted upon an arm projecting from the outer end of the sleeve,
and having its free end adapted to engage with a link of the chain.
3. In a pipe wrench, the dog consisting of a body, and an insertable toothed
Begment.
4. The combination with the internally threaded sleeve, and the chain connected
thereto, of the dog pivoted upon an arm extending from the outer end thereof, its
free end adapted to engage with a link of the chain, and the screw threaded handle
inserted through the sleeve and engaging with the said dog.
Dated the 4th October 1892.
FELL & WILDING,
Agents for the Applicant.