IMPROVEMENTS IN WRENCHES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Phineas Lawrence at the
Office of the Commissioners of Patents on the 1st June 1882.
PHINEAS LAWRENCE of Farringdon Street, in the City of London, Merchant,
IMPROVEMENTS IN WRENCHES,
The first part of my Invention relates to screw-wrenches of that class commonly
termed, and known as "monkey wrenches," in which the adjusting screw is
stationary, and operates in a nut formed in the front of the sliding jaw; and my
first improvement consists in such a construction that the screw may be readily
disengaged from the nut, without changing the normal position of the hand while
operating, whereby the adjustable jaw may be quickly changed, from one position
to another, by the disengaged hand of the operator, or the jaw be allowed to
drop, as desired, by simply inclining the wrench, when the screw is again allowed
to resume its position, either to lock the jaw, or for use in ordinary manner.
Heretofore, the uniform method of applying the disengaging mechanism has been
to the moveable jaw, thus, the hand must follow the jaw in making adjustment,
or the position of the wrench must be changed in the hand of the operator. By
my Invention, I obviate these objections, and furthermore, I so apply the necessary
means, that no radical change is necessary in the regular manufacture of the
wrench.
For the purposes of my Invention the face of the shank is recessed, and a spring,
(by preference a tongue spring) is secured therein, its free end pressing outward
against the screw, in a grooved bearing. The inner semicircle of the thread forming
the nut, nearest to the face of the shank, is entirely cut away, and the end bearing
in the ferrule, slotted in the direction of the shank. The tension of the spring will
thus hold the screw snugly to its bearing, both in the segment of the nut, and
against the outer wall of the end bearing in the ferrule. and the screw may be
rotated by a milled head, adjusting the moveable jaw-as if no alteration had been
made as in ordinary practice, and securing the jaw against thrust. If it be desired
to make a quick and extreme change in the position of the moveable jaw, the
milled head is pressed by the thumb, towards the shank, thus forcing the screw

page_text: inwardly upon the shank, and detaching it from its bearing, in the semicircular
thread of the nut, thereby leaving the moveable jaw free to be slidden backwards
and forwards, to any desired position upon the shank. On pressure being removed
from the milled head, the spring instantly forces the screw back to its normal
position.
For economy of space, the spring, described, is let into the face of the shank, but
when secured thereto by a pin, or screw, the spring is attached to the face of the
shank, without being recessed. The spring may be so applied that its projecting
heels just fill the space between the sides, but are a trifle less in thickness than the
depth of the recess. The sides of the walls of the recess are then simply rivetted
over the spring.
My improvement may also be applied to existing wrenches.
The second part of my invention, consists in the construction and application of
the handle of the wrench, and in so designing the shank, and fixed jaw, relatively
to each other, that they may be produced from cast metal, and yet fairly equal in
strength, and durability what are now made from forged metal.
According to this part of my Invention the handle is made of metal (preferably
of cast or malleable iron) and in one piece, and is cast hollow and cylindrical, in
order to combine strength, durability, lightness and cheapness and the shank.
enters the handle only sufficiently far to ensure a firm bearing.
One method of forming the end bearing or ferrule, for the screw, and of securing
both the bearing and the handle to the shank, is as follows:-
The handle and bearing, or ferrule, are made in one piece, and the bearing in the
handle for the tail-piece of the shank is cored similarly and with the larger portion
of the handle, and then bored to drive snugly on to the tail piece (the adjustable
jaw, spring, and screw having been first placed in position) when the shank and
handle are simply keyed together by a pin, which pin should be of sufficient
strength to successfully resist the back thrust of the adjustable jaw and screw.
In another method, the end bearing and handle are made in separate parts, and
the handle is secured to the tail piece, by forming a nut in the bearing of the
handle.
Constructed, as herein described, there is but one face joint to fit, that is, to the
shank, and once properly put together there can be no possibility of future
loosening, from shrinkage, as is the case in wooden handles.
The larger cored portion of the handle may be strengthened by internal
longitudinal ribs.
In previous manufactures, of wrenches of this class, the fixed jaw and shank
have been made of forged wrought iron, while the adjustable jaw, and other
portions, have been made of malleable iron, or cast steel. This has been necessary,
though at increased cost of production, in consequence of the well known fact that,
in the casting of steel, or malleable iron, it has been generally practically impossible
to obtain uniformly sound castings, where a heavy portion joins a lighter portion
by sharply defined line of contact, as for instance, the shank to the jaw. The
reason assigned as the cause thereof is, that in annealing and cooling of the parts,
the disproportion of the mass as a whole, "sets up" internal strains, tending to
produce minute fractures, or flaws, which, in such parts, are at the line of
juncture the weakest point.
I now obviate this difficulty, first, by "coving," that is inwardly grooving or
curving the junction of the shank and jaw on all of its sides, which not only
strengthens the juncture in itself, but breaks the clearly defined and weakest-
point of contact in the expanding and contracting process of casting and annealing.
I furthermore cast the fixed jaw hollow, coring it out in such relative proportion
to the shank, that the mass of the jaw and shank, relatively, are the same; and
hence will be acted upon in like manner with like degrees of temperature.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Phineas Lawrence in the Great Seal Patent Office on the
28th November 1882.
PHINEAS LAWRENCE of Farringdon Street in the City of London, Merchant
IMPROVEMENTS IN WRENCHES
My Invention relates to screw wrenches of that class commonly termed and
known as monkey wrenches, in which the adjusting screw is stationary and
operates in a nut formed in the front of the sliding jaw.
My first improvement consists in such a construction of the wrench that the
screw may be readily disengaged from the nut without changing the normal
position of the hand while operating, whereby the adjustable jaw may be quickly
changed from one position to another by the disengaged hand of the operator, or
the jaw be allowed to drop, as desired, by simply inclining the wrench, when the
screw is again allowed to resume its position, either to lock the jaw or for use in
ordinary manner.
Heretofore the uniform method of applying the disengaging mechanism is to the
moveable jaw, thus the hand must follow the jaw in making adjustment, or the
position of the wrench be changed in the hand of the operator. By my invention
I obviate this objection, and furthermore, I so apply the necessary means that no
radical change is necessary in the regular manufacture of the wrench.
In the accompanying drawings, Figure 1 is an upright side elevation of a
common form of monkey wrench, portions. being shewn as cut away to more clearly
shew my improvement. Fig. 2 is an upright cross section on line 4 of Fig. 1, and
Fig. 3 is a face view of a portion of shank with spring.
In Fig. 1, a is the ferrule, forming an end bearing for screw b. c is the adjustable
jaw, in which is formed the nut for screw. d is the shank and e the rigid jaw.
The ordinary method of operation requires no description.
For the purpose of my Invention, the face of the shank is recessed at f, figs. 1
and 3, and a spring, by preference a tongue spring, g, is secured therein, its free
end pressing outward against the screw in the grooved bearing h. The inner
semicircle of the thread forming the nut i, nearest to the face of the shank, is
entirely cut away, as seen at m (Fig. 2), and the end bearing h in the ferrule, fig. 1,
slotted in the direction of the shank. It will be seen that the tension of the
spring g will thus hold the screw snugly to its bearing both in the segment of the
nut and against the outer wall of the end bearing in the ferrule, and that the
screw may be rotated, by the milled head k adjusting the jaw c-as if no alteration
had been made-as in ordinary practice, and securing the jaw against thrust. If
it be desirable, however, to make a quick and extreme change in the position of the
movable jaw, the milled head is pressed with the thumb in the direction of the
shank, as indicated by the arrow x, when the screw will be forced inwardly upon
the shank and detached from its bearing in the semi-circular thread of the nut,
thus leaving the moveable jaw c free to be slidden backward or forward to any
desired position upon the shank. On pressure being removed from the milled
head, the spring instantly forces the screw back to its normal position, as shewn
in the figure.
The adjustment of the movable jaw may either be made by the disengaged hand
or by simply inclining the wrench up or down, as the case may be. The jaw will
gravitate to at least approximate the desired position upon the shank, when any
further adjustment for close work may be effected by rotating the screw.
In the formation of the threads of the screw and nut that construction similar to
a ratchet tooth will readily suggest itself as being best adapted for the purpose
herein described, the face of the thread receiving the thrust being at a right angle

page_text: to the axis of the screw. A square or nearly square shaped thread, however,
operates satisfactorily.
For economy of space the spring, as described, is let into the face of shank; but
when secured thereto by a pin or screw p, said spring may be attached to the face
of the shank, without being recessed. The spring may be so applied as shewn in
fig. 3, that the projecting heels s of the spring just fill the space between the sides,
but are a trifle less in thickness than the depth of the recess. The sides of the
-walls of the recess are then simply riveted over the spring, as shown at t.
As will readily be apprehended, any form of spring will answer for the described
purpose, although the style shewn is considered preferable.
To apply the invention to a wrench of the kind shewn and described it is only
necessary that the end bearing of screw be slotted or formed to permit a vibrating
or lateral motion and the removal of a portion of the thread forming the nut, while
to the component parts but one is added-the spring g.
The second part of my invention relates to the construction and application of
the handle of the wrench to the shank that the wrench as a whole shall be cheaper
to manufacture, stronger and more durable and better adapted to its purpose than
those heretofore used, and the third part of my invention consists in so designing
the shank and fixed jaw relatively to each other that the wrench may be produced
from cast metal, and yet fairly equal in strength and durability to wrenches now
made from forged metal.
Fig. 4 is a side elevation of an ordinary monkey wrench-less the adjustable
jaw and screw-showing my improvements thereon. Fig. 5 is a view similar to
Fig. 4 with the jaw and handle in longitudinal section; Fig. 6. is a cross section
on line y; Fig. 7. a transverse section on line z and Fig. 8. a modified cross section
of handle.
In wrenches of this class as heretofore made, the shank or bar d is formed with
a tailpiece over which is ordinarily placed the following combination of parts,
viz:- -a metal ferrule, next a wooden handle, and then a nut adapted to the
projecting end of the tail piece, firmly set up against the wood which latter keys
the entire structure. Sometimes a still greater combination of parts is used, but
this necessitates the separate fitting of the three distinct parts to each other and to
the tail piece in addition to the cost of the different parts.
As will be seen on referring to fig 4 and fig 5 of the drawings the shank does
not pass entirely through the handle A, but only enters sufficiently far to ensure a
firm bearing. The handle is made of metal, and in one piece (preferably of cast or
malleable iron) and is cast hollow and cylindrical or tubular, in order to combine
in the highest degree, strength, durability, lightness, and cheapness of production.
Two methods of forming the end bearing or ferrule n, for the screw and for
securing both the bearing and handle to the shank are shewn. That in fig. 4
represents both the handle and bearing in one piece. The bearing in the handle
for the tail piece d¹ of the shank is cored similarly and with the larger portion of
the handle, and then bored to drive snugly into the tail piece (the adjustable jaw
and screw having been first placed in position) when the shank and handle are
simply keyed together by a pin o, care being taken that the pin shall be of
sufficient strength to successfully resist the back thrust of the adjustable jaw and
screw.
In fig. 5. the end bearing and handle are shewn as made in separate parts, when
desirable to secure the handle to the tail piece by forming a nut r in the bearing of
the handle.
Thus, in the first instance, one part (the handle and end bearing) take the place
of three parts in previous methods of construction while the tail piece is shortened
at least two thirds of its length and it may be said its material so saved is formed
into a portion of the handle.
Constructed in the manner described, there is but one face joint to fit, that is to
the shank, and once properly put together there can be no possibility of future
loosening from shrinkage, as is the case in wooden handles while the article iş

page_text: quite as light, more durable, much stronger and more rigid, and costs less to
manufacture.
Fig. 8. shews how the larger cored portion of the handle may be strengthened
with slight additional material by internal longitudinal ribs.
In the previous manufacture of wrenches of this class, the solid jaw e and
shank & have been in the best practice uniformly made of forged wrought iron,
while the sliding jaw and other portions have been made of malleable iron or cast
steel. This has been necessary, though at increased cost of production in
consequence of the well known fact that in the casting of steel or malleable iron, it
has been generally practically impossible to get uniformly sound castings where a
heavy portion joins a lighter portion by a sharply defined line of contact, as for
instance, the shank to the jaw at v. The reason assigned as the cause thereof is
that in the after process of annealing and cooling of the parts the disproportion of the
mass as a whole "sets up" internal strains tending to produce minute fractures or
flaws, which in such parts are at the line of juncture, the weakest point.
This difficulty I now obviate, first, by "coving," that is, inwardly grooving or
curving the joint of the bar and jaw on all of its sides as at w; which not only
strengthens the joint in itself, but breaks the clearly defined and weakest point of
contact in the expanding and contracting process of casting and annealing. I further-
more cast the rigid jaw e, hollow, coring it out in such relative proportion to the
shank that the mass of the jaw and shank relatively are the same, and hence will
be acted upon in like manner with like degrees of temperature.
Having now described the nature of the said Invention, and in what manner
the same may be performed, I declare that I claim.
1. In an adjustable screw or monkey wrench in which the movement of the
sliding jaw is effected without changing the position of the hand during the
rotation of the operating screw, the combination of the semi-circular nut (as i),
screw (as b), slotted end bearing (as n), and spring (as g) for the purpose of
permitting the depression and detachment of said screw from the movable jaw,
whereby said jaw may be quickly slidden or allowed to gravitate to any position
on the shank, the screw being afterwards used to lock the jaw, as in the ordinary
manner.
2. In an adjustable screw or monkey wrench in which the movement of the
sliding jaw is effected without changing the position of the hand during the
rotation of the operating screw, the combination with the rigid jaw (as e), shank
(as d) sliding jaw (as c), semicircular nut (as i), screw (as b) and slotted end
bearing (as n) of a spring (as g) for the purpose specified.
3. The construction of the hollow, cylindrical or tubular metal handle in the
manner, substantially as herein described.
4. The combination with the jaw e and shank d of a hollow cylindrical or
tubular metal handle A, forming an end bearing for the adjusting screw, and
secured to the tail piece of the shank, substantially as shewn and described.
5. As an improvement in the manufacture of wrenches, the "coved" juncture w
of the shank and jaw for the purpose specified.
6. As an improvement in the manufacture of wrenches, the hollow jaw e, for the
purpose specified.
In witness whereof I the said Phineas Lawrence have hereunto set my
hand and cool this Twantuconand day of November in the vaur 1889