Improvement in Wrenches.
Year: 1893

page_text: Date of Application, 18th Apr., 1893-Accepted, 20th May, 1893
COMPLETE SPECIFICATION.
Improvement in Wrenches.
I, JOHN A. BARKER of Pasadena in the County of Los Angeles and State of
California, United States of America, Barber, do hereby declare the nature of this
invention and in what manner it is to be performed, to be particularly described
and ascertained in and by the following statement :-
My invention relates to that class of wrenches in which a movable jaw is
mounted upon a bar or lever having one or more sides of its perimeter plain and
having another side of its perimeter threaded to receive the threads of a locking
nut which secures the jaw in place upon the bar.
One object of my invention is to cheapen the construction and increase the
convenience of operation, also to so construct the wrench that the different parts
can all be cast of malleable iron and put together without machine work.
Another object of my invention is to so construct the wrench that the sliding
jaw can be moved freely back and forth upon the bar of the wrench and when the
jaws are clamped upon the nut to be turned, the movable jaw and its shank will
also be clamped firmly upon the bar so as to relieve the screw threads from all
liability of being jammed, bruised or broken by the strain upon the jaw.
The accompanying drawings illustrate my invention.
Fig. 1 is a side view of my wrench gripped upon a nut.
Fig. 2 is a vertical longitudinal mid-section of the wrench.
Fig. 3 is a transverse section on line a-x Fig. 1.
Fig. 4 is an end view of the sliding jaw and the locking or clamping nut detached
from the wrench bar.
Fig. 5 shows the several parts separate. The locking nut is partially broken
away to expose the interior.
My invention consists in the combination of a bar A having an unthreaded side
and having the fixed jaw B at one end thereof arranged to project from the
unthreaded side of the bar and having the opposite side of the bar provided with
seginental spiral cam threads a; a movable jaw C provided with the shank grooved
to receive and arranged to fit upon the unthreaded side of the bar and provided
at the end with the nut-retaining projection d and having the outside of one of the
walls c of the groove chambered to receive the segmental threads e of the locking
nut E and the locking nut E which is fitted upon and surrounds the bar and
shank and is provided with internally arranged segmental threads e adapted to be
chambered against the wall c and adapted to engage the segmental spiral cam
threads a of the bar so that when the locking nut is rotated to force the segmental
threads into engagement with each other the effect will be both to force the sliding
jaw toward the fixed jaw and at the same time to force the shank against the bar
and clamp the two firmly together.
In practice the several parts may be constructed by any desirable mode of
manufacture but they are adapted to be cast of malleable iron and then the finished
castings can be put together without difficulty by first placing the locking nut upon
the shank in the manner indicated in Fig. 4, then the nut is turned to the left to
withdraw the segmental threads from above the groove in the shank, thus leaving
a free passage for the bar into the groove. When the bar has been passed through
the groove, the handle H is secured in place and the wrench is ready for operation,
the segmental threads of the nut being chambered against the thin wall c, the
sliding jaw with its locking nut is free to slide back and forth upon the bar. To
use the wrench the sliding jaw is slid forward until the nut to be turned, (indicated
by I in Fig. 1) is clamped between the two jaws. Then the locking nut is turned

page_text: to the right, thus causing the segmental spiral threads of the locking nut to engage
the segmental spiral cam threads of the bar, thus forcing the jaw toward the nut
and at the same time drawing the shank firmly against the bar and binding it to
the bar; the pressure of the sliding jaw is thus sustained by the engaging plain
face of the bar and shank and by the threads of the bar and the locking nut which
are in contact with each other, and thus all danger of bruising the threads is
avoided. The cam form of the segmental threads adapt the device for use even
when the threads become worn, for the reason that the tendency is continually to
take up the wear when the locking nut is tightened. The wall c' of the shank is
of such thickness as to practically fit the cylindrical bore of the locking nut upon
that side so that if the threads fit each other too loosely they will be prevented
from passing out of engagement with each other, for the reason that the thick
wall will serve as a stop to prevent the segmental thread of the locking nut
from passing too far.
When the locking nut is turned it forces the movable jaw forward against the
nut to be turned and the nut is clamped so tight thereby that the wrench will
sustain itself as indicated in Fig. 1 and this is true whether the wrench is above
the nut as shown in said Fig. 1 or beneath the nut. The friction of the cam
threads secures the jaw against accidental displacement whether the wrench is upon
the nut or not and the jaw cannot be moved until the locking nut is rotated to the
left, thus relieving the engagement of the threads.
The nut retaining projection d prevents the nut from slipping off from the shank
when the sbank is in place on the bar.
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. The wrench set forth consisting in the combination of the bar having an
unthreaded side and having the fixed jaw at one end thereof arranged to project
from the unthreaded side of the bar and having the opposite side of the bar
provided with segmental spiral cam threads; the movable jaw provided with the
shank grooved to receive and arranged to fit upon the unthreaded side of the bar
and provided at the end with the nut retaining projection d and having the outside
of one of the walls of the groove chambered to receive the segmental thread of
the locking nut; and the locking nut fitted upon and surrounding the bar and
shank and provided with internally arranged segmental threads adapted to be
chambered against the wall of the groove and adapted to engage the spiral cam
threads of the bar, so that when the locking nut is rotated to force the segmental
threads into engagement with each other the effect will be to both force the sliding
jaw toward the fixed jaw and at the same time force the shank against the bar and
clamp the two firmly together.
2. The combination of the bar having an unthreaded side and having the fixed
jaw at one end thereof arranged to project from one side of the bar and having the
opposite side of the bar provided with segmental cam threads; a movable jaw
provided with a shank grooved to receive and arranged to fit upon the unthreaded
side of the bar and having the outside of one of the walls of the groove chambered
to receive the segmental threads of the locking nut; and the locking nut fitted
upon and surrounding the bar and shank and provided with internally arranged
segmental threads adapted to be chambered against the wall of the shank and
adapted to engage the segmental cam threads of the bar.
3. The combination set forth of the bar provided with segmental cam threads;
a sliding jaw having its shank arranged to slide along such bar and a locking
sleeve encircling such shank and provided with segmental internal threads arranged
to engage the cam threads on the bar to clamp the shank of the sliding jaw against
the bar when the sleeve is rotated in one direction and to release the shank there-
from when the sleeve is rotated in the other direction, whereby the sleeve and jaw

page_text: may be moved along the bar and locked, and the wear of the threads will be taken
up by the cam shape of the threads upon the bar and the sleeve locked upon the
bar thereby.
JOHN A. BARKER.
W. P. Thompson & Boult,
Agents for the Applicant..