Year: 1899

page_text: Date of Application. 18th Nov., 1899
Complete Specification Left, 20th Aug., 1900-Accepted, 22nd Sept.,
1900
I, WILLIAM HENRY ROBINSON, of Marion, Iowa, U.S.A., Inventor, do hereby
declare the nature of this invention to be as follows:-
This invention relates to wrenches; the object of my improvements being to
provide a wrench which will be partially automatic in its adjustment to nuts of
various sizes.
One form of my improved wrench comprises a shank, which also constitutes a
handle, and which has a fixed head. The inner edge of the shank is serrated.
A movable jaw is reciprocable on the handle and has a recess in its face to.
contain a plate which is kept normally pressed slightly outwards beyond the
face by a spring recessed into the rear of the jaw, pressing on a rearward projec-
tion on the plate, and retained in place by a screw-stud. The aforesaid projection
has an inclined upper edge upon which rests the upper end of an aperture in a bar
vertically and reciprocably arranged in a vertical aperture extending through
the head. The bar is formed at its lower end to engage the serrations in the
shank, and is pressed downwardly at its upper end by a spring retained in the
vertical aperture by a screw-stud.
In use, the jaw can be freely moved along the shank against the nut to be
operated upon. When the handle has pressure applied to it to turn the nut,
the plate in the jaw is pressed inwardly, and the inclined projection on the
plate being also moved inwardly, the spring above the vertical bar is free to
press the latter downwardly into engagement with the serrations and prevent
movement of the jaw. When the pressure is released the spring behind the
inclined projection forces the plate outwardly again into its normal position,
and the incline on the projection raises the bar, thus freeing the jaw.
In a second form of the invention, the vertical bar may be raised by an
inclined slot in the projection on the plate. A recess having inwardly projecting
flanges is formed in the back of the jaw and contains a flat spring, which is
retained by the flanges and bears constantly against the end of the projection on
the plate.
In a third form of the invention, the rearward projection of the plate is pivoted
to a bell-crank pivoted in a recess at the rear of the plate, and also pivoted to the
upper end of the vertical reciprocable catch-bar.
In a fourth form of the invention, the plate rests against the face of the
jaw which is inclined and slotted vertically to permit the passage therethrough of
a spring secured to the back of the plate and to the back of the jaw; the tendency
of the spring being to press the plate normally downwards and away from the face
of the jaw. The spring extends rearwardly and presses upon a dog or dogs
which project over and engage the serrations in the shank when pressure is
applied to the plate by the nut or the dogs are pressed downwardly by the thumb
of the operator. In consequence of the face of the jaw, and also the rear of the
plate being inclined the plate moves longitudinally in a direction parallel with
the shank when pressed downwardly by the spring.

page_text: In use, the action of the second, third and fourth forms of the invention is
similar to that described with reference to the first.
Dated this 17th day of Novambon 1900
P. R. J. WILLIS,
Agent for Applicant.
1, WILLIAM HENRY ROBINSON, of Marion, Iowa, U.S.A., Inventor, do hereby
declare the nature of this invention and in what manner the same is to be, per-
formed, to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to produce a monkey wrench for pipes or nuts
capable of very quick and close adjustment to varying kinds of work the con-
struction being simple strong and comparatively inexpensive.
The invention will be fully hereinafter described and claimed, reference being
had to the accompanying drawings, forming a part of this specification, in which-
Figure 1 is a view in perspective of a wrench embodying my invention, Fig. 2
is a central longitudinal section of the same, but with smooth instead of serrated
jaws. Fig. 3 is a side view of the dogs which hold the sliding jaw and of the
stirrup for disengaging them. Fig. 4 is a transverse section in the line x-x of
Fig. 2 as seen from the left of said line. Fig. 5 is a part central longitudinal
section of the sliding jaw and serrated shank of a wrench showing a modified
form of my invention.
Similar letters of reference indicate corresponding parts.
The body of the wrench does not differ materially from others in common use,
consisting of a head A, serrated shank A¹ and handle A². On the shank is
mounted the sliding jaw, which embodies the principal feature of this invention.
B is a rectangular slide fitting the correspondingly shaped shank A¹ and
adapted to slide freely thereon. This terminates at one end in a jaw B. The
inner face of this jaw is preferably at an angle to the adjacent face of the other
jaw, and to it is fitted, as by a sliding T-shaped connection a correspondingly
angled plate B². The face of this plate as well as the outer jaw may be serrated,
as in Fig. 1, and for use as a pipe wrench this construction is necessary; but
the sliding plate serves a useful purpose as an adjunct to a nut wrench, as will
hereinafter appear, and both it and the outer jaw may in such case be plain as
shewn in Fig. 2. At its lower end it should be notched to straddle the shank as
it moves down, the lower ends of the plate normally extending as low or a little
lower than the upper face. of the shank, so as to give a bearing at all times to
anything the wrench may grasp and for the full length of the jaws, if necessary.
The plate is forced outwardly to normal position by a suitable spring C¹, which
may be a part of the spring C governing the jaw-holding dogs hereinafter to be
described. This terminal spring C passes through a slot B3 in the sliding jaw
and at its inner end engages a stud B, which prevents the plate B³ from moving
out further than the normal position shewn in Figs. 1 and 2.
In a suitable recess formed in the upper part of the slide B is placed a pair
of dogs D and D¹, the teeth of which are adapted to engage the corresponding
teeth formed on the adjacent side of the shank A. By reference to Fig. 3 it will
be seen that the teeth of these dogs are set dodging with respect to each other, so
as to engage the shank teeth alternately and by this means it is possible to obtain

page_text: a fairly close adjustment of the sliding jaw and at the same time have teeth on
the shank and dogs coarse enough to give the requisite strength. The dogs are
held in engagement with the shank by springs and C3 which are preferably
united at the base C, where the spring as a whole is attached to the jaw B¹ by a
screw E.
It will be seen that the construction is such that no pivot pin is required for
the dogs, the pivotal part D³ being retained between the spring C and a
shoulder B³ formed in the slide B. This shoulder coincides with a corresponding
shoulder 13 near this end of the dog, and the end thrust is thus taken by the
end of the dog and not by a pivot-pin, with a great increase of strength as a
result of such construction.
The dogs are disengaged from the shank by a lifter F which is in the nature
of a stirrup with inwardly turned extremities F". This stirrup passes through
suitable holes in the slide, each side of the shank, from the back side of the
wrench, the loop being always in a position to be conveniently reached by the
thumb of the operator and serving also for the movement of the sliding jaw
back and forth on the shank for adjustment. A shoulder Be at this end of the
slide co-acting with a shoulder D* near the end of the dogs prevents them from
slipping out of their seat endwise.
In the operation of the wrench it is but necessary to slide the movable jaw
up against the nut or pipe to be held and permit the dogs to engage the shank.
Then on turning the handle in the direction indicated by the arrow the inclined
plate B2 is forced towards the shank, tightening the jaws effectually on the object
held by them.
In the modification of my invention shown in Fig. 5 the sliding jaw B has in its
front face a recess G in which fits loosely a plate H which may have either a
plane or serrated outer face. The plate H is connected to a rearwardly extend-
ing member J which adjacent its rear extremity has an upwardly extending
inclined surface J and the rear extremity of which enters a recess J
in the back of the upwardly extending portion B₁ of the sliding
jaw B. Within the recess J2 is a spring J, kept in place by
the set screw J, normally tending to force the plate H out of the
recess G. Within a slot K, extending through the upper portion of the sliding
jaw B, is a plate L having teeth L' at its lower extremity corresponding to the
serrations of the part A' of the shank. The plate L may have two teeth as shewn,
or may be wide enough to have three or more teeth. The plate L is slotted
angularly transversely at a point in its vertical height to permit of the member J
being passed therethrough before its attachment to the plate H so that the
angled side of the slot rests upon the angled portion of the member J. Within
the upper portion of the recess K a spring L2, kept in place by the set-screw L",
tends to force the plate L towards the shank.
In operation, the sliding member B being pushed forward against the nut or
pipe to be manipulated, pressure on the shank forces the plate H inwards against
the action of the spring J3 and as the inclined portion J¹ of the member J recedes
the plate L is forced downwards by the spring L² into engagement with the serra-
tions on the shank and on release of pressure on the shank the parts return to
the normal position shewn in Fig. 5.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
(1) In a wrench, the combination with a jaw having a shank and handle rigidly
attached thereto, the shank being serrated on one side, of a sliding jaw mounted
on said shank, a pair of dogs mounted in a recess in said sliding jaw, adjacent to
the serrated side of the shank, with ends abutting on shoulders formed in said
jaw-slide, springs adapted to hold said dogs in engagement alternately with said
shank, and a lifter extending through the slide portion of the jaw from the

page_text: opposite side and engaging the free ends of the dogs substantially as and for
the purpose set forth.
(2) In a wrench, the combination with a fixed jaw and its serrated shank, of a
sliding jaw movable on said shank, and having an angled plate fitted to slide on
the angled face of the jaw to tighten the wrench on the work, serrated dogs
mounted in suitable recesses in the slide portion of the jaw, a suitable lifter
therefor adapted to be pressed by the thumb of the operator to disengage the
dogs, and springs to hold the dogs normally in engagement with the shank, and
to force the inclined plate outwardly to normal position, substantially as and for
the purposes set forth.
(3) In a wrench, the combination with the fixed jaw and its serrated shank,
of a sliding jaw movable on said shank, and having an inclined face adjacent to
the fixed jaw, an inclined plate having an interlocking, sliding connection with
said inclined jaw, a spring adapted to force it outwardly to normal position, a
stop to limit its outward movement, a pair of alternately engaging dogs co-
acting with the serrated shank, springs to hold them in engagement, and a lifter
adapted to disengage them, substantially as and for the purposes set forth.
(4) In a wrench the combination with the fixed jaw and its serrated shank,
of a sliding jaw movable thereon, and having an inclined face opposite the fixed
jaw extending some distance below the face of the shank fronting said jaws,
an inclined plate having an interlocking, sliding connection with said inclined jaw,
and notched at its end adjacent to the shank, so as to straddle the same when
forced downwardly, a spring to force it normally outwardly, a stop to limit its
outward movement, and means substantially as described for retaining the sliding
jaw in any desired position.
(5) In a wrench the combination with a fixed jaw having a serrated shank
rigidly attached thereto, of a sliding jaw mounted on said shank, a plate mounted
in a recess in the face of said sliding jaw and attached to a rearwardly extending
member having an inclined surface on one portion of its length, a toothed plate
adapted to reciprocate within a slot in the sliding jaw and engage with the
inclined portion of the said rearwardly extending member, a spring in rear of the
rearwardly extending member held in a recess in the sliding jaw by a set-screw
and normally tending to force the first named plate away from the face of the
sliding jaw, and a spring in rear of the toothed plate held in a recess in the
sliding jaw by a set-screw and normally tending to force the said toothed plate
into engagement with the serrated shank substantially as and for the purposes
set forth.
T: 10th day of August 1900
P. R. J. WILLIS,
Agent for Applicant.