Year: 1897

page_text: Date of Application, 25th Feb., 1897
Complete Specification Left, 25th Nov., 1897-Accepted, 8th Jan., 1898
I, ALBERT ERNEST JENKS, of Clyde House, Heath Town, near Wolverhampton
in the County of Stafford, Manufacturer, do hereby declare the nature of this in-
vention to be as follows:
This invention has for its object to provide a movable spanner which will hold
firmly a nut of any size (within certain limits), which shall be of a simple and cheap
construction, and free from the faults usually observed in movable spanners
actuated by a screw and nut arrangement, or any similar contrivance, for operating
the moving jaw of the spanner.
At the back end of the fixed part of the spanner a volute cam is secured on a
spindle or rivet, and the back end of the shank of the moving jaw of the spanner
bears directly against the periphery of the cam. As the said cam is turned on its
axis in one direction of rotation, its volute-shaped periphery bears against the
back end of the shank, aforesaid, and presses inwards the moving jaw of the
spanner, and as the cam is turned in the opposite direction its periphery passes
out of contact with the shank, aforesaid, and allows the moving jaw to be opened.
When the moving jaw presses the hinder end of its shank against the periphery
of the cam, the friction thereby occasioned prevents the cam from turning, and the
moving jaw is thus securely prevented from giving way when the spanner is
applied to a nut or the head of a bolt. The cam is pivoted between the two sides
of a backwardly-extended portion of a sheath within which the shank of the
moving jaw is guided, and the cam may be securely fixed in any position into which
it may be turned by clamping it tightly between the two sides between which it
is pivoted, for which purpose the pivot pin consi ts of a screwed pin having a
milled or other nut on one end by which it may be tightened up to clamp the two
sides against the cam.

page_text: invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:—
A movable spanner, as usually constructed, with a screw and nut arrangement
or other screw contrivance for operating the moving jaw, is subject to the in-
convenience that the setting of the moving jaw is a somewhat tedious operation,
and that the spanner cannot be made so thin or flat from side to side as is
desirable for a portable spanner such as is used by cyclists; and the object of
this invention is to provide a movable spanner which shall be of a simple and cheap
construction and free from the inconvenience experienced in using such spanners
of the ordinary type..
A movable spanner constructed according to this invention is illustrated by
the drawings herewith.
Figure 1 is a side elevation of the spanner, with one side of the sheath, in which
the shank of the moving jaw is guided, cut away, and with the pivot pin in section.
Figure 2 is an inner, oriunder, edge view of the spanner.
Figure 3 is a transverse section through the spanner, taken on line a
A is the fixed jaw of the spanner, and is formed with a shank B which forms a
portion of the handle. C is the moving, jaw, and is formed with a shank D which
is capable of sliding endways within a sheath E. The sheath constitutes, the
remaining portion of the spanner handle, and is formed, conveniently of sheet
metal, of the trough-shape shewn by Figure 3, having two sides a which are riveted,
by means of rivets b, to opposite faces of the shank B, and a part.c which joins
together the inner edges of the sides a and keeps the sliding shank D between
such sides. I is a cam mounted upon a pin G, between backwardly-extended
ends of the sides a of the sheath. The pin G is carried in such extended
ends of the sides a, and the cam is capable of being turned upon the pin. The
hinder end d of the shank D comes, when the moving jaw C is moved sufficiently
outwards, against the periphery of the cam, and such periphery 's formed of such
shape, preferably volute as shewn, that when turned in one direction, while the
hinder end d of the shank D is against it, it will press such shank, and conse-
quently the moving jaw C, inwards, and when turned in the opposite direction
will pass out of contact with such shank and allow the moving jaw to be opened.
A slotted opening g is formed through the part c of the sheath, and a lug h projects
from the edge of the shank D through this opening. This lug is to enable the
shank D to be readily slid back to bring its rear end against the periphery of the
cam when the cam has been turned into position to allow of the moving jaw being
opened.
When the spanner is being used to turn a nut or other screwed part, the pressure
against the moving jaw C causes the hinder end d of the shank D to press against
the periphery of the cam, and the friction thereby occasioned will usually prevent
the cam from turning, and consequently prevent the moving jaw yielding back; but
to ensure that the cam will be securely held, under all circumstances, in any position
into which it may have been moved, a screw bolt, provided with a nut e having a
milled edge or otherwise adapted for convenient manipulation, may be used as the
pin G. When the cam has been turned into any required. position, it n may be
securely fixed therein by clamping the backwardly-extended ends of the sides a
of the sheath against its opposite faces by means of the nut e,
When the periphery of the cam is formed of a volute shape, a shoulder f occurs
between the portions of greatest and least projection, as shewn, and the spanner
is readily set for use with the largest size of nut or bolt head for which it is
adapted by pressing the moving jaw backwards with one hand to keep the hinder
end d of the shank D constantly against the periphery of the cam, and turning
the cam in the direction of the arrow with the other hand until the shoulder f
comes against the inside or underside of the hinder end of the shank D.
The main advantage, however, in using a cam of volute shape arises from the
fact that an entire revolution, or nearly so, of the cam is necessary to cause: the full
traverse of the moving jaw inwards, and thus the curve of the periphery of the

page_text: cam is such as to approximate more nearly to the curve of a circle struck from the
centre on which the cam turns than is the case with cams of other shape, and offer
more direct resistance to the backward pressure of the moving jaw shank, with the
result that the cam is less liable to turn under such pressure than in the case of
cams of other shape.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:
1. A movable spanner having a fixed jaw, a moving jaw, a moving jaw shank,
a guide for the moving jaw shank, and a cam pivoted at the hinder end of the
handle in the plane of the moving jaw shank, substantially as described.
2. A movable spanner having a fixed jaw, a moving jaw, and a volute-shaped
cam for use in setting the moving jaw, substantially as described.
3. A movable spanner having a fixed jaw, a moving jaw, a moving jaw shank,
a guide for the moving jaw shank, a cam pivoted at the hinder end of the handle
in the plane of the moving jaw shank, and means for securing the cam in any
position into which it may have been moved, substantially as described.
4. A movable spanner having a fixed jaw A, a moving jaw C, a moving jaw
shank D, a sheath E within which the shank D is a sliding fit, and a cam F
mounted between backwardly extended portions of the sheath sides upon a pin
carried by such backwardly extended portions, substantially as described, and
shewn by the drawings.
5. A movable spanner constructed as described and shown by the drawings
herewith.
Dated this 92nd day of Nazzamhar
1007
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.