New or Improved Cam Mechanism.
Year: 1895

page_text: Date of Application, 2nd July, 1895-Accepted, 17th Aug., 1895
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of
New York, in the United States of America, Sewing Machine Manufacturers.]
New or Improved Cam Mechanism.
I, WILLIAM HARVEY INSLEE, Manager of The Singer Manufacturing Company,
Kilbowie, Dumbartonshire, do hereby declare the nature of this invention and in
what manner the same is to be performed as communicated to me to be particularly
described and ascertained in and by the following statement:-
My invention relates to a mechanical movement whereby a positive intermittent
rotary motion may be imparted to a wheel or shaft from a cam or cams on a
continuously rotating shaft, the construction of the parts being such that if the
direction of rotation of the driving cam or cams be reversed the direction of rotation
of the driven wheel or shaft will also be reversed, so that if my invention be
incorporated into a machine (such, for example, as a fancy stitch sewing machine)
in which a particular timing of devices operated from the driven wheel or shaft
must always be maintained with relation to mechanism operated from the shaft
carrying the driving cam or cams, it will be impossible, by accidentally turning the
machine backwards, for one part of the mechanism to get out of proper timing
with the other.
In carrying my invention into effect the driving shaft is provided with a cam or
cams surrounded by a yoke forming part of a sliding and vibrating lever-dog the
opposite ends of which are adapted for alternate engagement with the teeth of a
gear wheel to be intermittingly rotated from the said driving shaft, said gear wheel
forming part of or being rigidly connected with any suitable cam, wheel or shaft
to be intermittingly driven, and the sliding and vibrating movements of the
said lever-dog being alternated with each other. Thus the said dog will, by
the movements of its driving cam or cams, first be slidden longitudinally to disengage
one of its ends from the teeth at one side of the gear wheel and engage its other
end with the teeth at the opposite side of said gear wheel, and said dog will then be
swung to rotate said gear wheel to the extent of one tooth, and in this swinging
movement of said dog its holding end will be held stationary by a fixed fulcrum
piece or guide so that said dog will swing from the end thus held fast. The
continued rotation of the cam or cams will next cause a reverse sliding movement
of the dog, to disengage its operating end from the teeth of the gear wheel and to
engage its holding end with the teeth on the opposite side of said wheel, and the
said dog will then be swung reversely, to its first position.
In the accompanying drawings Figs. 1, 2 and 3 are sectional elevations of my
invention, with the parts in different positions in the several figures. Figs. 4 and 5
are elevations, at right angles to each other, of the same. Fig. 6 illustrates a
slightly modified form of my invention.
A denotes a rotating driving shaft carrying a cam a surrounded by a yoke b
forming part of a sliding and vibrating lever-dog B one end of which is the
holding end and the other, b, the operating end of said dog. C denotes a gear
wheel (preferably formed as a crowu gear wheel, as shewn) and across which the
lever-dog slides so that the opposite ends of the latter may be alternately engaged
with and disengaged from the teeth of said wheel. D is a fixed fulcrum piece or
guide having a slot d entered by a portion of the holding end 61 of the lever-dog to
maintain that end of said dog stationary when the other end of the said dog is to

page_text: swing to rotate the wheel C, the said dog being of such length that when one of its
ends is fully engaged with the teeth of said wheel its other end will be fully
disengaged froin the wheel teeth, and being of such width that its end 6' may engage
both the teeth of the wheel C and the slotted piece or guide D.
The operation is as follows:-When the shaft A is rotated the cam a, acting on
the yoke b of the lever-dog will slide said dog across the gear wheel C to disengage
the holding end 6 of said dog from the teeth of said wheel and to engage the
operating end of said dog with the teeth at the opposite side of said wheel.
Continued rotation of said cam now causes the operating end of the lever dog to
swing to the extent of one tooth of the wheel C, the opposite end of said dog being
meanwhile maintained stationary by the fulcrum piece or guide D. The lever-dog
next slides back to disengage its operating end 6 from the teeth of the wheel and
to engage its holding end with said wheel, so as to positively hold the latter
stationary when, in the continued rotation of the cam, the said dog is reversely
swung to its first position. Thus the wheel C will be intermittingly and positively
rotated and will be positively locked from rotation during the return swinging
movements of the lever-dog one or the other of the ends of which will always be in
engagement with the teeth of the wheel C. A reverse rotation of the driving
shaft A will cause a positive reverse rotation of the said wheel C, so that a
mechanism operated by the latter will always be kept in proper timing with the
driving shaft A.
The operating cam may be made as a double cam a² and the yoke as a double
yoke 3, as shewn in Fig. 6, if desired, to give a swinging throw to said dog different
from its sliding throw, this construction of the cam and yoke being the same as that
long employed in four motioned sewing machine feeds.
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. The combination with a continuously rotating shaft provided with a cam, of
a sliding and vibrating lever-dog having a yoke embracing said cam, a wheel' or
device to be intermittingly rotated, and a fixed fulcrum piece or guide at one end
of said lever-dog and which prevents said end from vibrating when its opposite end
is to swing.
2. The combination with the shaft A having the cam a, of the wheel C to be
intermittingly rotated, the lever-dog B comprising the yoke b, surrounding said
cam, and the holding and operating ends or parts and 63, the said lever-dog being
entirely within the periphery of said wheel, and the slotted fulcrum piece or guide D
at one end of said lever-dog.
dow of Tul, 1905
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicant.