Improvements in Looking Devices for Securing Cams, Pulleys, Gear . Wheels, and other like Devices to Shafts.
Year: 1898

page_text: Date of Application, 18th Nov., 1898
Complete Specification Left, 28th July, 1899-Accepted, 2nd Sept, 1899
PROVISIONAL SPECIFICATION.
Improvements in Looking Devices for Securing Cams, Pulleys, Gear .
Wheels, and other like Devices to Shafts.
I, FERDINAND MORA CANDA, of 48, Central Park, South, Borough of Manhattan,
in the City and State of New York, United States of America, Manufacturer, do
hereby declare the nature of this invention to be as follows:-
This invention relates to locking devices for securing cams, pulleys, gear wheels,
and other like devices, to shafta; and it is more particularly applicable to the
cams of stamp mille.
A simple tapering key, fitting within a key seat in the shaft and in the cam,
such as is ordinarily used for securing pulleys, gear wheels, and like devices to
shafts, is not satisfactory for securing the cams of stamp mills, because upon each
shaft there are a number of cams arranged in different angular positions, so as
to lift and drop their stamps at different times, and consequently the cams are
not interchangeable, but must have their seats in different positions. This is
a serious objection, because it is necessary either to keep on hand, duplicates of
all the cams, or else, if but one extra cam be kept on hand, when it is to be sub-
stituted for a broken cam, a key seat must be cut in it, in a position correspond-
ing to the key seat of the broken cam; and since stamp mills are usually located
at a distance for machine shops, the key seat must be cut by hand, an operation
which is slow and difficult. Furthermore, if the broken cam be an intermediate
cam, all the cams between it and the end of the shaft must be removed in order to
put on the new cam. Moreover the keys are liable to work loose and in tightening
up a key, the cam may be broken, or weakened, by driving in the key too far.
The cam is also liable to be sheared off; and if the key seat in the cam on the
shaft becomes enlarged without a corresponding enlargement of the other key seat
of the shaft, it is impossible to fasten the cam firmly in place.
In order to avoid these disadvantages, a locking device has been used which
consists of an eccentric wedge extending partly around the shaft and lying in an
eccentric recess in the cam, the wedge being provided with one or more projec-
tions engaging recesses in the shaft, by which it is held in place. In this con-
struction, however, as the projections which key the wedge to the shaft are on the
wedge, such wedge must be placed upon the shaft before the cam is superimposed
upon it. This necessitates making the wedge recess the full width of the hub or
eye of the cam, so that the cam does not itself have a sufficient bearing on the
shaft, independent of the wedge, but has a bearing through a considerable portion
of the circumference of its eye against the wedge only. Consequently the wedge
recess cannot be caused to extend around the eve, but can occupy only a portion,
usually about one-half, of the circumference of the eye; and such a recess is very
difficult to cut because the cutting tool cannot move continuously in one direction
with respect to the cam, but its movements must be reversed at the completion
of every half revolution. Since the wedge recess must extend entirely across the
hub of the cam, the cam is much weakened; and further, if the curve of the
.

page_text: wedge fails to correspond exactly to the curve of the recess a rocking motion of
the cam upon the wedge will take place, since the cam has no independent con-
tinuous bearing upon the shaft. It has also been found, in the use of this locking
device, that since the cam may be moved laterally with respect to its wedge when
the parts are not locked, it frequently happens that the cam is not completely
superimposed over its wedge when the parts are locked; and consequently all the
working strain is thrown upon one portion of the cam, so that a fracture is likely
to occur.
Now the object of my invention is to overcome the above mentioned objections
and to provide a self-tightening locking device by means of which all the cams
may be made interchangeable, and which permits the cams to have a complete
bearing on the shaft independent of the wedge. My invention also permits the
wedge recess to be cut by a continuously revolving tool, and ensures a proper
superposition of the cam over the wedge.
According to my invention, I provide the hub or eye of a cam, pulley or like
device with a wedge recess or chamber occupying a portion only of the width of
the hub. I provide a wedge adapted to lie within the said chamber such wedge
being provided with a groove or slot adapted to receive a pin or projection pro-
vided on the shaft for the purpose of holding the wedge in place thereon. The
portion or portions of the eye at the side or sides of the wedge chamber are also
provided with a groove or slot to permit the cam or other device, with the wedge
in place within the wedge chamber, to be moved laterally along the shaft and over
the pin or projection thereon, so that the cam may be placed in its proper position
on the shaft, or removed therefrom, at will.
I prefer to employ a curved eccentric wedge which extends partly around the
shaft, and lies within an eccentric wedge chamber in the cam. The position of
each cam on the shaft is determined by the pin or other projection which extends
outward alightly from the shaft, and serves to hold the said wedge stationary.
The wedge chamber may extend completely round the eye of the cam, and may
be bored by a continuous motion of a boring tool (or of the cam with reference
to the tool) in one direction. In boring the cam, after the eye for the shaft has
been bored, the centres are shifted slightly to one side, and the wedge chamber
bored. The portions of the bore or eye of the cam which are on each side of the
wedge afford sufficient bearing to hold the cam steady on the shaft at all times,
independent of the wedge, which latter acts simply to prevent revolution of the
cam on the shaft. It is not however essential that the wedge chamber, and the
outer surface of the wedge, shall be circular in outline, or that the wedge chamber
and wedge shall correspond exactly in outline, although this is preferable. The
wedge chamber may also be formed in the casting instead of by boring.
I provide means for holding the wedge in place within the wedge chamber.
The said means may consist of springs arranged at the sides of the wedge. When
the wedge is in place within the wedge chamber, these springs fit into the grooves
formed in the sides of such chamber, and by pressing against the sides of these
grooves produce sufficient friction to prevent the wedge from slipping within
the wedge chamber unless moved positively. These springs also serve as keys to
prevent the wedge from dropping out of the wedge chamber. One spring only
may be used, but it is preferable to use a spring on each side of the wedge.
By these means the wedge will be held stationary in the wedge chamber of the
cam after being placed in such a position that its groove is in line with the
groove in the eye of the cam. The cam can thus be moved along the shaft until
it reaches the position which it is intended that the cam shall occupy, the said
grooves permitting it to pass any projections on such shaft Corre-
sponding to other cam positions, if necessary. When the cam reaches
its proper position, one of the pins or projections of the shaft will lie within the
groove of the wedge. The cam is then rotated in a backward direction upon
the shaft, the pin holding the wedge stationary until it is wedged tightly between
the cam and shaft, in which position the cam and shaft are rigidly connected.

page_text: When it is desired to remove the cam, a blow of a hammer in a forward direction
will loosen it, and it may be moved until the pin and the groove in the wedge are
opposite the groove in the eye when the cam may be moved laterally and so
removed from the shaft.
The use of this locking device does not involve the material weakening of the
hub of the cam.
My improved locking device is equally applicable to the locking of pulleys,
gear wheels, and the like, to shafts, when the parts are always to be rotated under
load in the same direction.
It is obvious that, instead of only one chamber and wedge, I may employ two
or more such chambers and wedges.
Date : 19th don of No 1000
Improvements in Locking Devices for Securing Oams, Pulleys, Gear
Wheels, and other like Devices to Shafts.
I, FERDINAND MORA CANDA, of 48, Central Park, South, Borough of Manhattan,
in the Oity and State of New York, United States of America, Manufacturer, 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 follow-
ing statement: —
This invention relates to locking devices for securing cams, pulleys, gear wheels,
and similar devices, to shafts; and it is more particularly applicable to the
cams of stamp mills.
A simple tapering key, fitting within a key seat in the shaft and in the cam,
such as is ordinarily used for securing pulleys, gear wheels, and similar devices to
shafts, is not satisfactory for securing the cams of stamp mills, because upon each
shaft there are several cams arranged in different angular positions, so as
to lift and drop their stamps at different times, and consequently the cams are
not interchangeable, but must have their seats in different positions. This is
a serious objection, because it is necessary either to keep in reserve duplicates
of all of the cams; or, if only one extra cam be kept in reserve, it is necessary
when such cam is to be substituted for a broken cam, to cut in it a key seat in
a position corresponding to the key seat of the broken cam; and since stamp
mills are usually located at a distance from machine shops, the key must be cut
by hand, an operation which is slow and difficult. Further, if the broken cam be
an intermediate cam, all the cams between it and the end of the shaft must be
removed in order to put on the new cam. The keys of such cams are also liable
to work loose; and, in tightening up a key, the cam may be broken, or weakened
by driving in the key too far. As the cam is held in place simply by the resist-
ance of the key to shearing, the key may in time be sheared off unless it be very
large. Furthermore, if the key seat in the cam or the shaft becomes enlarged,
without a corresponding enlargement of the corresponding key seat, it is impos-
sible to fasten the cam firmly in place.
In order to avoid these disadvantages, a locking device has been used which
consists of an eccentric wedge extending, partly around the shaft and lying in
an eccentric recess in the cam, the wedge being provided with one or more
projections engaging with recesses in the shaft, by which it is held in place.

page_text: In this construction, however, as the projections which key the wedge to the shaft
are on the wedge, such wedge must be placed upon the shaft before the cam
is superimposed upon it. This necessitates making the wedge-recess the full
width of the hub or eye of the cam, and this not only weakens the cam but also
renders it impossible for the cam itself to have a sufficient bearing surface on the
shaft, independent of the wedge. For this reason the wedge-recess cannot extend
Bround the eye, but can occupy only a portion, usually about one-half, of the
circumference of the eye; and such a recess is very difficult to cut because the
movement of the cutting tool must be reversed at the completion of every half
revolution. Further, if the curve of the wedge fails to correspond exactly to the
curve of the recess a rocking motion of the cam upon the wedge will take place,
Bince the cam has no independent continuous bearing upon the shaft. It has also
been found, in the use of this locking device, that since the cam may be moved
laterally with respect to its wedge when the parts are not locked, it frequently
happens that the cam is not completely superimposed over its wedge when the
parts are locked; and consequently all the working strain is thrown upon one
portion of the cam, rendering it very liable to fracture.
Now the object of my invention is to overcome the above mentioned objections
and to provide a self-tightening locking device by means of which all the cams
may be made interchangeable, and which permits the cam to have a complete
bearing on the shaft independent of the wedge. My invention also permits the
wedge-recess to be cut by a continuously revolving tool, and ensures a proper
superposition of the cam over the wedge.
According to my invention, I provide the hub or eye of a cam, pulley or like
device with a wedge-recess or chamber occupying a portion only of the width of
the hub. I provide a wedge adapted to lie within the said recess such wedge
being provided with a groove or slot adapted to receive a pin or projection pro-
vided on the shaft for the purpose of holding the wedge in place thereon. The
portion or portions of the eye at the side or sides of the wedge-recess are also
provided with a groove or slot to permit the cam or other device, with the wedge
in place within the recess, to be moved laterally along the shaft and over the
pin or projection thereon, so that the cam may be placed in its proper position
on the shaft, or removed therefrom, at will.
In order that my invention may be clearly understood and readily carried into
affect I will proceed to describe the same more fully with reference to the accom-
panying drawings, which illustrate my invention applied by way of example to
a cam such as is emploved in stamn mills, and in which:-
Figure 1 is a sectional elevation of a cam, the section being taken through the
wedge-recess on a plane at right angles to the axis of the cam;
Figure 2 is a section of the cam on an axial plane;
Figure 3 is a detail elevation of the wedge;
Figure 4 is a top view of the wedge, showing that surface which lies against the
shaft when the cam is in use; and
Figure 5 is a detail of that portion of the shaft on which the cam is to be
located.
Figures 3 and 4 are drawn to a slightly larger scale than are the other figures.
The cam 1 is, except as to the wedge recess. of ordinary construction. I employ
a curved eccentric wedge 4 which extends partly around the shaft 2, and lies with-
in an eccentric wedge-recess 3 in the cam. The position of each cam on the shaft
is determined by the pin 5 which extends outward slightly from the shaft, and
serves to hold the said wedge stationary.
The wedge-recess is of such shape that it may be bored by a continuous motion
of a boring tool (or of the cam with reference to the tool) in one direction. In
boring the cam, after the eve for the shaft has been bored, the centres are shifted
slightly to one side. and the recess 3 bored. This recess occupies but a portion
of the width of the hub of the cam, and the portions of the bore or eye of the cam
which are on each side of the wedge afford sufficient bearing to hold the cam

page_text: steady on the shaft at all times, independent of the wedge, which latter acts
simply to prevent revolution of the cam on the shaft.
At the sides of the recess 3, and near the bottom thereof I provide grooves 6
to receive springs, hereinafter mentioned, projecting from the wedge.
The wedge 4 may be formed in any convenient manner. Its inner face ia
circular in outline, the radius being that of the shaft, The outer face is also
circular in outline, the radius being that of the wedge-recess; and the eccentricity
of the outer face with respect to the inner face is the same as the eccentricity of
the wedge-recess with respect to the eye of the cam.
It is not however essential that the wedge-recess, and the outer surface of the
wedge, shall be circular in outline, or that the wedge-recess and wedge shall
correspond exactly in outline, although this is preferable. Moreover, instead of
forming the recess 3 by the action of a tool, it may be formed in the casting. A
bored recess, however, permits more accurate adjustment of the position of the
cam.
In the eye of the cam is a longitudinal groove 7, of a depth sufficient to enable
the cam to pass over the pin or projection 5. This groove may be formed when
casting the cam. In the inner face of the wedge 4 is a groove 8, also of a size to
permit the wedge to pass over the pin 5.'
The wedge is provided with side springs, 9, 9, formed by pieces of bent spring
wire, the ends of which fit into holes in the sides of the wedge. When the
wedge is in place within the wedge-recess, these springs fit into the aforesaid
grooves 6, and by pressing against the sides of these grooves produce sufficient
friction to prevent the wedge from slipping within its recess unless moved
positively. These springs also serve as keys to prevent the wedge from dropping
out of the recess. One spring only may be used, but it is preferable to use a spring
on each side of the wedge.
The manner of securing the cam to the shaft is as follows: The wedge 4 is
placed in the wedge recess of the cam and is moved until its groove 8 is in line
with the groove 7 in the eye of the cam. The cam is then placed upon the
shaft, and moved along the same until it reaches the position which it is intended
that the cam shall occupy, the said grooves 7 and 8 permitting it to pass any
projection 5 corresponding to other cam positions, if necessary. The springs 9
prevent the wedge from moving in its recess 3 while the cam is passing from one
pin or projection 5 to another, and so prevent the groove 8 in the wedge from
getting out of line with the groove 7 while the cam is being moved along the shaft,
When the cam reaches its proper position, one of the pins or projections 5 of the
shaft lies within the groove 8 of the wedge 4. The cam is then rotated in a back-
ward direction upon the shaft, the pin 5 holding the wedge stationary until it is
wedged tightly between the cam and shaft, in which position the cam and shaft
are rigidly connected.
When it is desired to remove the cam, a blow of a hammer in a forward
direction will loosen it, and it may be moved until the pin 5 and groove 8 are
opposite the groove 7, when the cam may be shifted laterally and so removed
from the shaft.
It is obvious that, instead of only one recess and wedge, I may employ two or
more such recesses and wedges.
In this locking device the position of the cam upon the shaft is determined by
the thickness of the wedge and the position of the pin 5; or, since the wedges
can always be made of the same thickness, it may be said that the position of the
cam on the shaft is determined solely by the position of the pin 5. All the cams
of a series may therefore be made interchangeable, no matter what may be the
intended angular position of each cam upon the shaft. The locking device is self
tightening and will never work loose. Since the cam has a sufficient bearing
on the shaft to support it firmly in all positions, independent of the wedge, there
can be no looseness or rocking motion of the cam on the shaft even should the
curvature of the wedge 4 fail to correspond with the curvature of the wedge.

page_text: recess of the cam. As the wedge-recess extends over only a portion of the width
of the hub of the cam, the cam is not materially weakened by the cutting of the
wedge-recess, nor is it weakened materially by the groove 7, which may be quite
shallow. Moreover since the wedge cannot become laterally displaced with respect
to the cam, said cam is always completely superimposed over said wedge, and the
working strain is thus uniformly distributed over the width of the cam.
Since all of the cams are interchangeable, if an intermediate cam of a series
breaks, the cams between it and the end of the shaft may be moved along, each
through one space, and the new cam placed upon the outside. And since the
wedge-recess 3 may be cut by a continuous motion of the tool, or of the cam with
reference to the tool, the work of cutting said recess may be effected quite cheaply.
My improved locking device herein described is equally applicable to the lock-
ing of pulleys, gear wheels, and the like, to shafts, when the parts are always to
be rotated under load in the same direction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I claim
for securing cams, pulleys, gear wheels and other like devices to shafts, is:—
1. A wedge arranged within an eccentric recess in the cam or the like and
having a groove to receive a projection upon the shaft, substantially as and for
the purposes described.
2. The combination with the aforesaid wedge of a spring or springs substantially
as and for the purposes described.
3. A locking device having its parts constructed, arranged and combined to
operate substantially as described with reference to the accompanying drawings
for the purposes specified.
Dated this 27th dox of T 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.