Improvements in Friction Clutches for Free Wheel Cycles.
Year: 1899

page_text: Date of Application, 27th Nov., 1899
Complete Specification Left, 31st Jan., 1900-Accepted, 13th Oct., 1900
PROVISIONAL SPECIFICATION.
Improvements in Friction Clutches for Free Wheel Cycles.
WILLIAM GODSON LITTLE, Blendon Grove, Bexley, Kent, Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention consists of a friction clutch suitable for attachment to the hub
of the hind wheel of a bicycle or to the crank axle or sprocket wheel and said
clutch is made up of three main parts (1) a steel ring screwed or otherwise fixed
to the hub of the wheel or to the crank axle or sprocket wheel, having a smooth
outer surface without notches. (2) Of an outer ring having a smooth inner surface
and on its outer surface a number of teeth engaging in the links of the chain
driving the cycle, or if the said clutch be fixed to the crank axle or sprocket
wheel, it has no leeth but a connection on its outer surface to which the break is
attached. (3) In the annular space between the smooth surfaces of the rings
are fitted a number of cams of such section (oval or otherwise) that when the outer
ring is revolved in one direction, they are turned by the friction of the rings so
that having one diameter larger than the breadth of the annular space into which
they fit, they clutch or jam between the rings, whilst when the ring is revolved
in the opposite direction they are turned by the friction so that they unclutch,
their smaller diameters being less than the breadth of the annular space between
the rings. In order to keep the cams apart and to keep them in a position of
constant contact with the surfaces of both rings, spacing blocks exactly fitting
the annular space are inserted between the cams, such blocks being cut in halves
and drilled to receive a small spring between the halves, thrusting either half
into contact with the cam next it.
The cams are so shaped on their smaller diameters that the blocks press onto
their lower parts on one side and onto their upper parts on the other side, thus
twisting them into constant contact with the smooth surfaces of the rings.
When the outer ring is so revolved as to unclutch the cams, the spacing blocks
form a support between the rings & run round on the smooth surface of ring (1).
If preferred I dispense with the spacing blocks and construct the cams of such
a shape that their alternate faces are concentric with the surfaces of the rings
and of such a length that the end of each cam touches the neighbouring cam-the
cams being enabled to rock the amount necessary to clutch by having their other
alternate & opposite faces cut away to allow of it. Constant contact of the cams
is obtained by inserting springs into holes drilled in their concentric faces &
which springs press upon the smooth surfaces of the rings keeping the cams tilted
so as to clutch instantly when the outer ring is revolved in the direction to cause
them to do so. The springs may be protected from wear by inserting small
hardened plugs into the holes above them to bear the friction of the rings.
Naam har 27th 1899
WILLIAM GODSON LITTLE,
Blendon Grove, Bexley, Kent.

page_text: O Ces Wheel Cycres.
I, WILLIAM GODSON LITTLE, of Blendon Grove, Bexley, in the County of Kent,
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: -
My invention has for its object to provide an improved friction clutch suitable
for attachment to the hub of the hind wheel of a bicycle, or to the crank-axle
or sprocket wheel; the said clutch being easily and economically made and very
durable. A clutch constructed in accordance with my invention consists of three
main parts (1) a steel ring fixed by screwing, or otherwise to the hub of the
wheel, or the crank-axle, or sprocket wheel; the said ring having a smooth outer
surface or periphery; (2) an outer ring having a smooth inner surface or peri-
phery, and on its exterior a number of teeth engaging with the links of the chain
driving the cycle; or, if the said clutch be fixed to the crank-axle or sprocket
wheel, it has no teeth but a connection on its exterior to which the brake is
attached; (3) a number of cams fitted in the space between the smooth outer
and inner peripheries of the said rings respectively. The said cams are of such
oval, or other shape that, when the outer ring is rotated in one direction the
said cams are turned by the friction of the rings into such a position that their
greater diameter or length (which is greater than the breadth of the annular space
in which the said cams fit between the rings) causes the said cams to clutch, or
jamb, between the said rings after the manner of struts, and so the rings rotate
together, whilst when the outer ring is not rotated, the said cams are, as the hub
rotates, turned, by the friction between them and the rings, so that the lesser
diameter, or breadth, of the said cams (which is not greater than the breadth of
the annular space between the rings) causes the said cams to no longer act as
struts and so the rings do not rotate together. To keep the cams at the proper
distance apart, and in constant contact with the surfaces of the rings, blocks or
distance pieces, may be used which can be either separate from the cams or formed
in one therewith.
In order that the manner in which my invention can be performed may be well
understood I will describe, with reference to the accompanying drawing, arrange-
ments according thereto applied to the hub of the hind wheel of a bicycle, and the
chain wheel thereon, from which its other applications will also be readily
understood.
Figure 1 is a transverse section of the clutch and part of the hub. Figure 2 is
a side view with the front annular covering plate removed. Figure 3 shews one
of the cams, or struts separately, and Figures 4 and 5 are half side views shewing
modifications in the construction of the clutch.
1 is a steel ring screwed to the hub A of the wheel and having a smooth outer
periphery and a flange a with a smooth inner face. 2 is an outer ring with a
smooth inner periphery and teeth outside for the engagement of the chain.
3 are the aforesaid cams acting as struts between the smooth surfaces of the
rings as aforesaid. The said cams are shaped as shewn clearly in the enlarged
view of one of them in Figure 3. care spacing blocks exactly fitting the width
of the annular space between the rings 1 and 2. The springs d cause the cams
to keep in constant contact with the smooth surfaces of the rings. e is an
annular plate secured in place by the screwed ring f so as to hold the cams 3
and blocks e in place.
When the chain ring 2 is driven in the direction of the arrow (Figure 2) the

page_text: friction of the rings turns the cams so that they clutch, acting as struts as herein-
before described and when the chain' wheel is not driven the wheel and inner ring
can run freely, the friction of the rings causing the cams to unclutch.
Figure 4 shews a modification wherein the blocks 3 are in halves drilled to
receive the springs & between the halves, which thus thrust either half into
contact with the cam next it.
Figure 5 shews a modification wherein the separate spacing blocks are dispensed
with, the cams 3 being made of such a shape that their alternate faces are con-
centric with the surfaces of the rings and of such a length that the end of each
cam touches the neighbouring cam, these additions forming virtually spacing
blocks in one with the cams. The cams are enabled to rock to the necessary extent
to clutch and unclutch by their other alternate and opposite faces being reduced
as shewn. Constant contact of the cams is obtained by inserting the springs
into holes in the extensions of the said cams the said springs pressing unon plugs
which bear on the smooth surfaces of the rings and so keep the cams tilted so as
to clutch immediately the outer ring is rotated in the direction to cause them
to do so.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. A clutch for the purposes stated consisting of two smooth faced rings in the
space between which are situated cams which, when the one part of the clutch is
moved in one direction act as struts to clutch the rings and when the said part
is not so moved the rings are unclutched, substantially as herein before described.
2. A clutch for the purposes stated consisting of the arrangement and combina-
tion of parts substantially as herein before described and illustrated in the accom-
panying drawing under the several modifications.
Dated this 31st day of January 1900.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.