AN IMPROVEMENT IN ADJUSTABLE SPANNERS OR WRENCHES, ALSO APPLICABLE AS A NUT LOCK
Year: 1878

page_text: LETTERS PATENT to William Robert Leeson, of Bridgwater, in the County
of Somerset, for the Invention of "AN IMPROVEMENT IN ADJUSTABLE
SPANNERS OR WRENCHES, ALSO APPLICABLE AS A NUT LOCK."
""
Sealed the 3rd May 1878, and dated the 2nd February 1878.
PROVISIONAL SPECIFICATION left by the said William Robert Leeson at
the Office of the Commissioners of Patents on the 2nd February 1878.
" AN
WILLIAM ROBERT LEESON, of Bridgwater, in the County of Somerset.
IMPROVEMENT IN ADJUSTABLE SPANNERS OR WRENCHES, ALSO APPLICABLE AS A
NUT LOCK."
My Invention relates, 1st, to adjustable spanners or monkey wrenches, and
consists in the employment (preferably in combination with the other devices here-
after described) of a sort of toggle bar, so applied between the movable jaw and the
shank or handle as to cause the latter to be. firmly gripped, so that on pressure
being applied to the said jaw in a direction tending to open or move it away from
the fixed jaw the grip becomes tighter and the movable jaw is more securely held
the greater the pressure upon it, whilst the said jaw may be freely moved in the
opposite direction.
A sliding block or bolster is applied between the end of the toggle bar and the
shank or handle of the spanner or wrench, to distribute the pressure of the bar
over a larger surface of the shank or handle, the face of the block and edge of the
shank along which it slides being serrated to ensure a firm bite and prevent
slipping.
A spring is applied to keep the toggle bar up to its work, so as to instantly
grip the shank and hold the jaw immovable immediately the pressure comes
upon it.
A releasing rod terminating in a button head is attached to the sliding block to
enable the spring to be compressed and the block and toggle to be drawn back free

page_text: from the shank, to allow the movable jaw to be slid back or opened out sufficiently
to take a nut or other object of any desired size.
The toggle bar, the sliding block or bolster, and the spring are contained wholly
within a cavity in the movable jaw enclosed by a covering plate. The toggle bar
is in a position almost perpendicular to the shank or handle of the wrench, and the
outward pressure on the immovable jaw tends to bring it more towards the per-
pendicular position, the length of the bar, however being such that it cannot quite
assume this positlon, and being confined within the jaw, the result of this tendency
is that the shank or handle is firmly gripped, as-above mentioned. The end of the
toggle bar is received in a half round groove in the back of the sliding block or
bolster, to keep the parts in their proper relative positions.
In using the spanner the jaws are opened by pulling the movable jaw and the
releasing button in opposite directions, so as to compress the spring and release the
grip of the toggle bar and block.
By retaining hold of the releasing button the jaw may now be drawn out to a
distance greater than the size of the nut, and the button being then released the
jaw may be slid up to grasp the nut, in which position it is immediately fixed
immovably by the toggle bar.
My Invention relates, 2ndly, to the application of the above-described toggle bar
as a nut lock. For this purpose it is fitted in a cavity in the nut and bears against
the bolt with one end, which is serrated to correspond to the screw threads of the
bolt, the other end being preferably rounded and received in a half round groove
in a bolster fitted in the cavity. behind the toggle bar. The toggle bar is almost
radial to the bolt. and is pressed in this direction by a spring, but is so confined
that it cannot quite assume this position, its direction being such that the nut can
be freely turned in one direction in order to tighten it up against the object it is
intended to secure, but is entirely prevented by the toggle bar from turning in the
opposite direction, so that it cannot be loosened.
The nut can only be unscrewed by compressing the spring and moving the toggle
bar out of contact with the bolt, which may be done by driving a wedge beside
the toggle bar on the opposite side to the spring.
In adjusting the nut to the bolt the toggle bar is first dropped into its place in
the cavity, the bolster then placed in position behind it, a wedge driven in beside
the toggle bar on the same side as the spring, which is. then compressed by a hand
vice or other tool slipped into its place, and the wedge withdrawn, and the nut is
secured.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Leeson in the Great Seal Patent Office on the 2nd
August 1878.
WILLIAM ROBERT LEESON, of Bridgwater, in the County of Somerset.
" AN
IMPROVEMENT IN ADJUSTABLE SPANNERS OR WRENCHES, ALSO APPLICABLE AS A
NUT LOCK."
My. Invention relates, first, to adjustable spanners or monkey wrenches, and
consists in the employment (preferably in combination with the other devices here-
after described) of a sort of toggle bar, so applied between the movable jaw and
the shank or handle as to cause the latter to be firmly gripped on pressure being
applied to the said jaw in a direction tending to open or move it away from the
fixed jaw, the grip becoming tighter and the movable jaw being more securely
held the greater the pressure upon it, without preventing the said jaw being freely.
moved in the opposite direction.
A sliding block or bolster is applied between the end of the toggle bar and the
shank or handle of the spanner or wrench to distribute the pressure of the bar over
a larger surface of the shank or handle, the face of this block and the edge of the
shank along which it slides being serrated to ensure a firm bite and prevent
slipping.
A spring is applied to keep the toggle bar up to its work, so that the bolster
shall instantly grip the shank, and its teeth engage with those of the shank so as
to hold the jaw immovable immediately pressure comes upon it, as in the act of
turning a nut or other object. A spring is not absolutely necessary (although it is
preferable to use it), as the serrations of the bolster and the shank will be caused
to engage, if, in the act of pushing the movable jaw up to its work, a slight pressure
is kept upon the releasing knob, hereafter mentioned, with the thumb.
A releasing rod terminating in a knob is attached to the sliding block or bolster,
to enable the spring to be compressed and the bolster and toggle to be drawn back
away from the shank until the teeth of the bolster are freed from those of the
shank, to allow the movable jaw to be slid back a sufficient distance from the
fixed jaw to take a nut or other object of any desired size.
The toggle bar, the sliding block or bolster, and the spring are contained wholly
within a cavity in the movable jaw enclosed by a covering plate. The toggle bar
is in a position almost perpendicular to the shank or handle of the wrench, and the
outward pressure on the movable jaw tends to bring it more towards the perpen-
dicular position, the length of the bar however being such that it cannot quito
assume this position and being confined within the jaw, the result of this tendency
is that the shank or handle is firmly gripped, as above mentioned. The end of the
toggle bar is received in a half round groove in the back of the sliding block or.
bolster to keep the parts in their proper relative positions.
In using the spanner the jaws are opened by pulling the movable jaw and the
releasing knob in opposite directions, so as to compress the spring and release the
grip of the toggle bar and bolster from the shank.
By retaining hold of the releasing button the jaw may now be drawn out to a
distance greater than the size of the nut or object required to be acted upon, and.
on the knob being let go the jaw may be slid up to grasp the nut or other object,
in which position it is immediately fixed immovably by the toggle bar and bolster,
gripping the shank or handle.
My Invention relates, secondly, to the application of the above-described toggle
bar as a nut lock. For this purpose it is fitted in a cavity in the nut, and bears
against the nut with one end and with the other end against a bolster which is
formed to correspond to the screw threads of the bolt, the surface of the bolt
between the screw threads and the corresponding surface of the bolster being
serrated, as before, to ensure a firm grip. The toggle bar is almost radial to the

page_text: bolt and is pressed towards this position by a spring, but is so confined that it
cannot quite assume this position, its direction being such that the nut can be
freely turned in one direction in order to tighten it up against the object it is
intended to secure, but is entirely prevented by the toggle. bar from turning in the
opposite direction, so that it cannot be loosened.
The nut can only be unscrewed by moving the toggle bar in the direction of the
spring and thus compressing the latter, which may be done by driving a wedge
beside the toggle bar on the opposite side to the spring.
In adjusting the nut to the bolt the bolster is first dropped into its place in the
cavity, the toggle bar then placed in position behind it, a wedge driven: in beside
the toggle bar on the same side as the spring which is then compressed by a hand
vice or other tool slipped into its place and the wedge then withdrawn.
vice or other tool slipped into its place and the wedge then withdrawn.
DESCRIPTION OF DRAWINGS.
Figure 1 represents an adjustable spanner or monkey wrench, the movable jaw.
being drawn in section in order to exhibit the devices of my Invention. In this
Figure the compression bolster, which is also represented partly in section, is shown
as engaged in the teeth on the shank or handle.
Figure 2 shows a similar view of the same spanner with toggle bar and bolster
drawn back, and released from the teeth of the handle by pulling the releasing
knob and the movable jaw in opposite directions.
Figure 3 represents a cross section of the spanner on line 1-1, Figure 1, and
Figure 4 represents a top view of the bolster separately.
Figures 5, 6, and 7 illustrate the Invention applied as a nut lock, Figure 5 being
a plan of a nut and bolt with the Invention applied thereto, and Figures 6 and
vertical sections of same, showing the Invention applied to a bolt with V shaped
and square screw threads respectively.
The same letters of reference indicate the same parts in all these Figures wherever
they recur.
Referring to Figures 1, 2, 3, 4, A is the fixed jaw; B, the movable jaw; and C,
the shank or handle of the wrench or spanner. The jaw A is fixed to the shank
or handle C, and the movable jaw B is fitted to slide along the said shank or
handle as usual; D is the toggle bar; E, the compression bolster or block; and F,
the spring bearing against the said bolster, all of these being contained in a
čavity G, formed in the movable jaw B, and retained in said cavity by a cover
plate b (Figure 3) screwed or rivetted thereto; H is the releasing knob attached to
the bolster E by a rod h sliding through a hole in the jaw B.
The ends of the toggle bar D are rounded or semi-cylindrical, and they are
received in corresponding rounded recesses, the one at the bottom of cavity G and
the other in the back of the bolster E, so that it may work freely between the two
positions shown in Figures 1 and 2.
The shank or handle C is preferably slightly rounded at the lower edge, or it
may be flat, and this edge is serrated or provided with inclined or saw-shaped
teeth c along that edge for a sufficient distance, and the adjacent surface e of the
bolster E is correspondingly hollowed, or otherwise shaped, and serrated to engage
with the teeth or serrations c on the handle.
.
It should be understood that the serrations are, for the sake of clearness, shown
in the annexed Drawings on an exaggerated scale. In practice they would be
much finer, or smaller, and closer together.
The spring F may be a spiral or other spring, as preferred.
The movable jaw B is at all times free to slide along the handle towards the
fixed jaw A, but immediately any pressure comes upon it tending to force it away
from the fixed jaw the shank or hand C is by the action of the toggle immediately
gripped between the compression · bolster E and the back part B of the movable
jaw, which is thus immovably fixed. The movable jaw B can only be slid away.
from the jaw A when the bolster E is drawn back by pulling the knob H and the

page_text: jaw Bin opposite directions, so as to disengage the teeth e'of the said 'bolster' from
the teeth c of the handle C, as shown in Figure 2; is a flat spring contained in
で
a recess of the cheek of the movable jaw, and bearing against the side of the
shank C with just sufficient friction to prevent jaw B sliding too freely towards
the jaw A.
Referring to Figures 5, 6, and 7; D is the toggle bar; E, the bolster; and F,
the spring, as before, all received in a cavity G in the nut I; K is the bolt.
The form of the bolster, which corresponds to the thread of the screw, is shown
in the two sectional views. The grooves k of the bolt K between the screw threads
are serrated, and the corresponding parts e of the bolster are similarly serrated, as
shown, to engage with the serrations of the bolt and prevent any unscrewing of the
nut or screw. To admit of these serrations in a threaded bolt the threads.
are not close together, as on an ordinary V threaded screw, but are separated by a
narrow square groove, as shown in Figure 6.
It should be observed that the bolt thread must be a little deeper than the
thread of the nut, so that the latter shall not be injured by contact with the
serrations in the bolt, the reverse being of course the case with the compression
bolster, the threads on which must be rather deeper than the bolt thread, so that
the serrations e on the bolster may engage with the serrations k on the bolt and so
that the bolster may clear the crown of the bolt threads. It is not imperative to
serrate the grooves between the bolt threads, provided the bolster E is serrated
at e, as the bolster being in any case made of hardened steel may have sufficient
bite on the bolt to avoid the necessity of serrating the latter. The toggle bar D
is made rather larger at the upper end d, and rests on a slight shoulder to prevent
it falling too far through the nut; or instead of the toggle bar and compression
bolster extending completely through the nut, as shown, they may be shorter, the
cavity in the nut in that case being closed at the bottom.
It will be obvious that both in the wrench or spanner, and likewise in the nut
lock, the toggle bar D may be used without the compression bolster, provided the
end of the toggle bar which is to engage with the serrations of the wrench handle
or of the bolt (as the case may be) be correspondingly serrated. In this case the
spring would bear against the toggle. As in the case of the nut the toggle bar
could not be withdrawn from the nut wben engaged in the threads of the bolt, a
bolster is put at the opposite end of the toggle bar between it and the end of the
cavity G, so that by first drawing out the bolster the toggle bar can be released.
I however prefer to use the compression bolster, as shown in the Drawings.
Having described the nature of my Invention, and the manner of performing the
same, I declare that what I claim as my Invention to be protected by the herein-
before in part recited Letters Patent is,-
1st. The combination with the sliding jaw of an adjustable spanner of a toggle
bar, so applied as to cause the shank to be gripped more tightly, the greater the
force tending to move the sliding jaw away from the fixed one (whether a com-
pression bolster be interposed between the toggle and the shank or handle or not),
substantially as set forth.
2nd. The combination of the toggle bar and compression bolster, fitted to work
in a cavity in the movable jaw of an adjustable spanner or wrench, and applied as
herein shown and described, the bolster being serrated to engage with serrations on
the shank or handle, substantially as shown and described for the purpose
specified.
3rd. The combination of the toggle bar, serrated compression bolster spring and
releasing knob, fitted to work in a cavity in the movable jaw of an adjustable
spanner or wrench and applied to act on the serrated shank or handle, substantially
as shown and described.
4th. The combination with a nut and bolt of a toggle bar fitted to work in a
cavity in the nut, and so applied and acted on by a spring as to cause the bolt to
be gripped more tightly, the greater the tendency of the nut to unscrew from the

page_text: bolt or vice versa (whether a compression bolster be interposed between the toggle
and the bolt or not) substantially as specified.
5th. The combination of the toggle bar, the bolster, and the spring fitted to work
in a cavity in a nut and applied to act on the screw bolt, substantially as and for
the purpose set forth.
In witness whereof, I, the said William Robert Leeson, have hereunto set my
hand and seal, this First day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
WILLIAM R. LEESON. (L.S.)