IMPROVEMENTS IN WRENCHES."
Year: 1878

page_text: A
LETTERS PATENT to Gerald Clarence Hopper, of 38, Southampton Buildings,
London, Engineer, for the Invention of "IMPROVEMENTS IN WRENCHES."
communication from abroad by John Wesley Hyatt, of Newark, New Jersey,
United States of America, Gentleman.
Sealed the 20th December 1878, and dated the 9th October 1878.
"
COMPLETE SPECIFICATION filed by the said Gerald Clarence Hopper at the
Office of the Commissioners of Patents on the 9th October 1878.
GERALD CLARENCE HOPPER, of 38, Southampton Buildings, London, Engineer.
IMPROVEMENTS IN WRENCHES." A communication from abroad by John Wesley
Hyatt, of Newark, New Jersey, United States of America, Gentleman.
NATURE AND OBJECTS OF THE INVENTION.
This Invention relates to an improvement in wrenches, and consists in providing
the wrench bar upon one side with a mutilated female thread, which is preferablý
undercut, and which is so situated as to be capable of being engaged by a male
screw, also preferably undercut, and mounted on axles provided at each end, which
have their bearings in the jaw of the wrench at each side of the slot, the bearings
being so constructed as to permit the male screw to he rotated or moved towards
or away from the wrench bar on lines parallel therewith, the said male screw being
guided somewhat by the sides of the slot, wherein it fits smoothly, being of a
diameter equal to or greater than its length to prevent its tilting or canting and
consequent binding upon being moved.
The axles of the screw are provided with or operated upon by suitably placed
springs, causing the screw to engage the female thread, or permitting the screw to
be raised clear of the said thread.
The jaw of the wrench can be moved on the wrench bar towards the head of the
wrench, the threads of the screw and mutilated female thread passing over each

page_text: .
other without obstruction; or the jaw can be retracted toward the handle by
raising the screw clear of the female thread, which permits the motion last afore-
said.
The male screw may be constructed as above indicated, though it is plain that it
would be preferable but not so satisfactorily if of greater length than diameter.
The above construction permits the male screw to be moved toward or retracted
from the wrench bar in such manner that its axis is always parallel with the axis
of the wrench bar; this prevents uneven movement of the screw, and ensures the
full contact of the screw and female thread when the former is depressed, and
instant and entire disengagement from end to end as the screw is elevated.
It is also plain that in the above device the jaw can be moved to assume a
relation to the head very nearly approximating to the size of the object to be
gripped, and then by rotating the screw any excess of space be taken up, and a
firm grip secured; but should the object be of a size exactly corresponding to the
distance between the position, the jaw can be moved toward the head of the
wrench, then it is only necessary to suitably advance the jaw into contact with
the obiect
view of the sliding jaw.
CIGYNGTON, partly in section; and Figure 4 is a sectional
GENERAL DESCRIPTION.
In the accompanying Drawings 1 represents the wrench bar provided on one
side or edge with the inutilated female thread 2, which is under cut, that is, the
threads have an inclination transversely downward toward the handle of the
wrench. Upon the wrench bar 1 and capable of movement is mounted the jaw 3,
having in that portion thereof facing the female thread a slot 4, the walls or sides
of which are parallel, and preferably vertical, and in them are provided the elongated
bearings to receive the axles at each end of the male screw 5, and thus enable its
rotation or retraction from the wrench bar or its approach thereto.
The male screw 5 fits smoothly in the slot 4, the walls of which assist in directing
its movement, and is preferably of less length than diameter to the end, that in
being moved it will not be canted or tilted, which would have a tendency to cause
it to bind between the walls of the slot. The edges of the threads of the male.
screw 5 are milled to facilitate its being rotated, and are so cut as to readily and
fully engage the parts of the mutilated female screw 2 when the two are in the
locking position.
The screw 5 is cylindrical in cross section, and its axles aforesaid are operated
upon by springs placed in the bearings thereof, so as to give the screw a tension or
pressure toward the mutilated female thread, and to hold the screw in contact
therewith.
As the threads of the male screw and female thread incline parallel to each other,
and on planes traverse to the wrench bar, the jaw of the wrench can be advanced
toward the head thereof, as desired, by simply moving it in that direction, but the
same construction of the said threads prevents the retraction of the jaw unless the
screw is raised; hence, should the object to be gripped be of such size as to be
capable of being accurately held between the head and the jaw in any position
they can assume it is only necessary to advance the latter; but should said object
be of less size than the distance between the head and the jaw, when the latter is
advanced as near as it can be to the object, then it is only necessary to move the
jaw as close to the object as possible and rotate the male screw, which further
advances the jaw, taking up the excess of space, and bringing the jaw firmly
against the object. In this movement the jaw is fully sustained on the wrench bar

page_text: in all positions, and has no play or lost motion, whereby great strength is obtained,
and an absolutely accurate and certain grip is secured.
To move the jaw toward the handle of the wrench it is only necessary to elevate.
the male screw clear of the female thread, which done, the jaw can be moved
cither up or down on the bar, as desired.
It should be stated that by the term parallel movement, as given in the summary
of the Invention herein after, is intended a movement of a male screw toward or
away from a female screw in such manner that in said movement the axis of said
bodies are parallel to each other.
Having now described and particularly set forth the nature of the said Invention,
and the manner of carrying the game into effect, I would have it understood that
what I claim as the Invention and desire to secure by Letters Patent is,-
Firstly. In a wrench a mutilated female screw in combination with a male screw,
the latter mounted in spring bearings in the jaw of the wrench, which is capable
of movement on the wrench bar, substantially as specified.
Secondly. In a wrench a male screw secured in the jaw of the wrench, and
provided at each end with spring bearings, which causes it to engage a mutilated
female screw on the wrench bar, and permits the jaw of the wrench to be moved
toward the head of the wrench, as stated, or toward the handle of the wrench by
raising the male screw and retracting the jaw, substantially as described.
Thirdly. The male screw 5 having the edges of. its thread milled and mounted in
spring bearings at each end, substantially as set forth.
Fourthly. A wrench jaw provided with a slot, upon each side of which is placed
an elongated slot or bearing to receive the axles of a male screw, and permit the
movement and rotation thereof in the slot, substantially as specified.
Fifthly. A wrench bar having a mutilated female thread in combination with a
inale screw, capable of being rotated, and also of being moved toward or away
from the wrench bar, its axis in such movement being parallel to the axis of the
wrench har, the movements being independent of each other, substantially as set
forth.
Sixthly. A locking mechanism engaging the wrench bar at more than one point,
capable of independent rotation, and of independent parallel movement toward or
from the wrench bar, substantially as set forth.
Seventhly. In a wrench a male screw mounted in the jaw of the wrench, and
capable of being rotated and moved with its axis parallel to the surface it engages,
substantially as specified.
Eighthly. In a wrench a male screw of a diameter equal to or greater than its
length fitting in a slot in the jaw of the wrench, and capable of independent
rotation and parallel movement in combination with a mutilated female thread,
substantially as set forth.
Ninthly. In a wrench a locking mechanism placed upon one side of the wrench
bar, and capable of being either rotated or moved with its operative surface parallel
to the surface it engages, substantially as specified.
In witness whereof. I, the said Gerald Clarence Hopper, have hereunto set
my hand and seal, this Ninth day of October, in the year of our Lord One
thousand eight hundred and seventy-eight.
GERALD CLARENCE HOPPER. (L.S.)