Year: 1886

page_text: We, FRANK ARMSTRONG and NATHANIEL WARNER VANDEGRIFT, residing at
Bridgeport, in the County of Fairfield and State of Connecticut, in the United
States of America, 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 wrenches which have one stationary and
one movable jaw and particularly to the means employed for shifting and retaining
the movable jaw in position.
Prior to our invention a large number of devices for accomplishing the shifting
and retaining of the movable jaw have been suggested, among which may be
mentioned the arrangement of a serrated cam pivoted upon the movable jaw and
bearing against the bar upon which the said jaw slides, and provided with an
operating lever projecting out to a convenient point for grasping in order to be
moved to operate the cam. This device possesses a great disadvantage in being
liable to become wedged when too much strain is put upon the jaws, rendering it
difficult to free the cam from its wedged position.
Another distinctive class of devices for operating the movable jaw is shown in
the patent of the United States granted to F. Armstrong, No. 274544. In this
two operating means must necessarily be employed one for moving the jaw up
firmly against the work, and the other for releasing a serrated plate which bears
against a similarly serrated face of the bar of the wrench.
Our invention has for its object to provide a means for locking the movable jaw
in place, and readily releasing the same, which shall be simple in construction and
readily operated and which shall at the same time be durable, not liable to get out
of order, readily renewed and which shall hold the jaw positively and accurately
at any given point to which it may be moved. And with these ends in view my
invention consists of a wrench having an ordinary stationary jaw and shank with
a movable jaw adapted to reciprocate upon the shank of the stationary jaw, and
provided with a recess in which is arranged a spring toggle clamping block or
lever and releasing latch, in such manner that the strain exerted by the use of the
wrench shall be in a line resulting from the resolution of forces, or coincident with
a plane passing through the strongest portions of the wrench and whereby also the
movable jaw is protected against any backward or loosening movement while
the wrench is in use; our invention consists further in the details of construction
for carrying out the generic principles of operation as will be hereinafter fully
explained.
The clamping block D, as will be observed is angular in form the serrated area
being obtuse to the pivoted portion so that the reacting strain exerted by the
contact of the serration on the arm and the shank A, will always be in radial lines

page_text: passing through the center of the clamp pivot, and thus tend to hold said clamp to
its proper working position.
In order that the construction and arrangement of our improvement may be
clearly understood and others skilled in the art enabled to make wrenches
embodying them I will now proceed to describe the same in connection with the
accompanying drawing in which:
Fig. 1 is a side view of a wrench embodying our improvements.
Fig. 2 is a similar view with the side of the sliding jaw broken away to show
the interior disposition of the parts.
In these drawings A, represents the shank of the wrench, and B, represents the
stationary jaw which is secured to or formed with the shank.
C, represents the movable jaw which has an opening for the passage of the rod
or shank A, upon which it is designed to slide back and forth to increase or
diminish the size of the opening which receives the work. The sliding jaw C, is
hollowed out as shown to form a chamber, in which the mechanism for holding the
same in place is assembled.
As a convenient means of securing the jaw against backward movement upon
the bar A, when a strain having a tendency to effect this is exerted we provide
the surface of the bar, which is adjacent to the chamber in the hollow jaw with a
series of serrations extending a distance equal to that travelled by the jaw in
changing its positions.
These serrations are curved on their edges which face the handle and are straight
on their other face so that anything which is designed to engage with them may
freely slide over them toward the stationary jaw but movement in a reverse
direction will be prevented by coming in contact with the square edges.
D represents a toggle block or lever which is pivoted within the chamber in the
sliding jaw at the forward end thereof and its lower face is provided with teeth
which engage with those on the bar A. The corner of the chamber in which the
toggle is pivoted is rounded and the end of the said toggle which bears against
the inner face of the jaw is similarly rounded so that the toggle may be turned to
any position desired and still the bearing against the face of the jaw be pre-
served in order that no strain be brought upon the pin upon which the toggle
is pivoted.
Upon a ledge formed upon the lever is a pin H, around which is placed a coil
spring G, the upper end of which rests in a countersink I, in the upper wall of the
jaw. This spring continuously presses down upon the lever and keeps it in
The preferred
engagement with the teeth upon the bar until raised free thereof.
means of accomplishing this raising is the lever E, which is mounted upon a pin K,
passing through the shell of the jaw.
The rear end of the lever projects out from the jaw a convenient distance to
afford a ready means of grasping when it is desired to release the stop and the
forward end rests under a lip J, on the rear end of the lever D.
In assembling the parts the recessed jaw is taken before being put upon the
part A, and the holes necessary for the reception of the screws F and K are drilled;
next the toggle D, is placed within the chamber with its end bearing against the
rounded portion provided for its reception and the screw upon which it vibrates is
placed in position. The opening in the toggle is slightly greater than is actually
required for the accommodation of the pin so that enough play will be allowed to
insure the contact between the toggle and the inner face of the jaw. After the
toggle is placed in its appropriate position the spring is mounted upon the pin on
the toggle and its upper end placed in a seat formed in the recess of the jaw as
clearly illustrated; finally, the lever E is placed in position with its forward end
under the nose J, on the stop, and secured in that position by inserting the pin K,
upon which it vibrates. These parts being all in place, the stop D, is held up by
depressing the lever E, and the jaw is slid upon the rod to its proper position.
When this has been done the lever E, is released and the catch allowed to drop into
contact with the serrations on the bar after which the tool is ready for use.

page_text: The clamping block is so arranged and so shaped that the strain exerted against
the operating face of the movable jaw will be directed toward the solid shank of
the stationary jaw in an oblique line through the center of the pivot of the
clamping block thus relieving said pivot from any undue strain or friction and
enabling the operating latch lever to be operated with the minimum amount of
force. It will also be observed that the construction and arrangement of the
toggle block and latch lever are such that the spring employed for forcing the
former into its locking position also maintains the latter in the proper position to
make it instantly effective for releasing the toggle block when desired. The latch
lever it will be observed is in such position that it may readily be reached by the
operator, so that the wrench can be operated with one hand.
It will also be seen that the several parts of our improved wrench are so
constructed and assembled that they may all be made by the simplest mechanical
methods, and that they are readily placed in position, and in the event of it
becoming necessary to substitute a new piece at any time, for any reason, that such
part or parts are interchangeable and adapted to be placed in position with the
exercise of little or no expert mechanical knowledge and with great celerity.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:
1. The combination in a wrench, of the stationary jaw, the shank to which the
said jaw is attached, and the movable jaw having the recess and provided with a
locking lever mounted within the recess, and bearing upon the shank of the wrench,
the point at which the said lever is pivoted and that at which it bears on the
shank, being coincident with the line of strain exerted in the use of the tool.
2. The combination in a wrench, of the stationary jaw, the shank to which the
said jaw is attached and the movable jaw having the recess and provided with
the locking lever, pivoted within the said recess and bearing upon the shank, the
said lever being provided with a curved upper end taking into a similarly curved
indentation in the recess and being mounted loosely upon the pin by which it is
secured in place.
3. In combination with the stationary jaw and shank, the movable jaw, having
the retaining lever arranged as described and a spring arranged upon the retaining
lever to depress it, and a lever pivoted contiguous to the retaining lever and
capable of being moved to raise the same.
4. In combination with the stationary jaw and the movable jaw having the
recess, the retaining lever provided with the lip or teat in its rear end and pivoted
within the said recess, the spring arranged between the top of the chamber and the
retaining lever, and the operating lever pivoted in the rear of the chamber having
one end resting beneath the teat on the retaining lever and the other projecting
beyond the jaw, in order to be readily grasped.
5. In a wrench, the combination of the stationary jaw, the shank provided with
serrations on its upper face, the movable jaw having the recess in which is pivoted
the retaining lever having the serrations on its lower edge, the spring bearing upon
the said retaining lever and the operating lever for raising the retaining lever,
substantially as described.