Improved Cycle Wheel Coupling or Clutch Device.
Year: 1897

page_text: Date of Application, 24th Nov., 1897-Accepted, 9th July, 1898
Improved Cycle Wheel Coupling or Clutch Device.
A communication by JOHANN PUFF, of 50, Schwabacher Strasse, Fuerth, Bavaria,
in the Empire of Germany, Purveyor of Comestibles.
I. WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for Foreign
Patent Solicitors, 6, Lord Street. Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster. 118, New Street, Birmingham, in the County
of Warwick, and 322, High Holborn, in the County of Middlesex, Civil Engineer,
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
following statement;―
This invention relates to an improved cycle wheel clutch or coupling device.
It consists of a means for enabling the rear sprocket on the back wheel of bicycles
and the like to be engaged or disengaged by means of a coupling or clutch device
in such a way that when desired the back wheel may continue to travel whilst
the pedals remain stationary. This is attained by mounting the rear sprocket
on a cone which fits as a friction coupling over a ring on the hub.
The invention is shown in the accompanying drawings: in which,
Figure 1 is a part elevation of a wheel hub with the sprocket and clutch in
section.
Figure 2 is a plan of the means for expanding the friction ring.
Figure 3 is a side view of the friction ring.
Figures 4 and 5 are part elevation and plan respectively of a cycle wheel
showing the means for operating the clutch.
C is a section of the rear wheel hub on which a narrow ring is firmly cast.
The periphery of this ring is bevelled. On this ring there is mounted a second
ring B which is an open ring with a spring action and is provided with a suitable
groove, corresponding to the bevelled edge of the ring to which it normally
clings by its spring action. K is a gap between the ends of the open ring B
adapted to receive a device for expanding the ring as hereinafter described.
The chain wheel Fruns on the hub C on a suitably arranged ball bearing.
The balls of the ball bearing are shown at L. The chain wheel F which is firmly
screwed on a cast metal piece A and is also held by screwed rings M is shown
only in Figure 1. The cast metal piece A has an annular projection N into
which is screwed a ring N' forming a groove to engage over the spring ring B.
The cast metal piece A and chain wheel F when revolved will bear loosely on
the balls L around the axle without rotating the axle with them. As soon however
as the spring ring B is pressed apart or expanded its outer surfaces will bear or rub
on the parts N N' and the axle will then be set in rotation by the friction. To
ensure that the rings B and C will always rotate together, a pin or projection is
Provided on the former at some suitable point to project radially into a socket in
the ring C. The expanding of the spring ring B takes place by means of a
spring D shaped like a pair of tongs which engages in the gap K of the ring B.

page_text: Between the longer arms of this spring an oval disc E is mounted which when it
is turned to the extent of 90° lies with its greatest diameter between the arins of
the spring D, thus forcing them apart and opening or expanding the ring B.
The rotation or turning of this oval dise E is effected by a square bar running
from the axle of the back wheel up to the rim of the same in such a way that it
fits at one end into a four cornered opening in the oval disc E and at the other
end into a round projection at the point P, Figure 4. On this rod there are
formed projections QQ Fig. 5 which project at opposite sides of the bar 0.
When the wheel is running, these projections will encounter one of two small
levers RR mounted on the wheel frame. In the position shown in the drawing
(Figure 5) the projection Q will encounter the lever R which stands at right
angles to the frame whilst the projection Q will clear the lever K¹.
By this contact the lever Q will be turned from the position shown to an angle
and with it also the square rod O and thus also the oval disc E.
The tongs shaped spring 1 will thus be opened or closed and correspondingly
also the ring B will be expanded against N and N or released and therefore the
chain wheel F will be clutched to the back wheel hub or otherwise.
For releasing the clutch an elbow lever S is turned by means of any suitable
arrangement from the handle bar and the lever will thus be moved into a
vertical position whilst lever I will be turned into an inclined position. In the
succeeding revolutions of the back wheel the projection Q will then encounter
the lever R and the square rod will then be turned in the other direction and
with it the oval disc E. thus causing the tongs shaped spring 1) to contract the
ring B and thus release the clutch.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is:-
1. A cycle wheel coupling or clutch device characterised by the rear sprocket
being mounted on ball bearings on the back wheel hub together with a cast
metal cone (A) which has a recess or annular groove (NN) in which engages an
expanding or spring ring (B) carried by a ring (C), fixed to the wheel hub, said
spring ring (B) being adapted to be expanded by suitable means so as to bear on
the annular groove (N N') and thereby couple or clutch the rear cycle wheel to the
sprocket substantially as hereinbefore described.
2. In a cycle wheel coupling or clutch device of the kind described the means
for operating the spring ring of the clutch consisting of a tongs-like spring (D)
mounted on the hub and engaging at one end in a gap of the expansion ring (1)
and at the other end embracing an oval disc (E) adapted when turned to open the
tongs or close them as the case may be in order to expand or release the spring
ring (1) in the manner set forth and a square rod (0) engaging in a recess in sail
oval disc and extending to the rim of the wheel, said rod having lateral projec-
tions (QQ) adapted to be engaged singly by pivotted projections (R and R)
arranged on the cycle frame and adapted to be operated by suitable means from the
handle bar of the machine in order to encounter one or other of the projec-
tions (QQ) of the square rod to engage or disengage the coupling, substantially
as described.
3. The general construction and combination of parts taken as a whole forming
the improved cycle wheel coupling or clutch device substantially as herein before
described and illustrated.
Dated this 23rd day of November 1807
W. P. THOMPSON & Co.,
Agents.