Year: 1899

page_text: :—
I, CHARLES THOMAS BROCK SANGSTER, General Manager of the Cycle Com-
ponents Manufacturing Company, Limited, of Bournbrook, near the City of
Birmingham, do hereby declare the nature of this invention to be as follows:-
This invention has relation to friction clutches, principally for use in connec-
tion with the free driving wheels and back-pedalling brake mechanism of cycles
and motor cycles.
The new or improved clutch action, in which no rollers or balls or other loose
wearing parts are employed, consists in the use, as the clutching medium, of
rocking and sliding wedge elements, whose fulcra are excentrically situated,
both in respect to the said wedges and (in the case of a free wheel cycle clutch)
in respect to the centre of the hub upon which the clutch is mounted.
One, two or more of such wedges may be employed, and each of them is
located within a space bounded inwardly by a straight edge part or extended
cross flat formed on the periphery of the inner disc or driven element, and a
portion of the curved inner periphery of the outer toothed ring, chain wheel or
driving element. The space is thus of the figure of a double wedge with a curved
outer edge, or of the segment of a circle, the outer edge of the loose wedge piece
is shaped to conform to the curve of the space, whilst one opposed flat of the
double wedge is longer than the other, and the excentric fulcrum upon which
the block may be turned is at the junction of the two flats so that the wedge
piece has a long and a short side. Coming under the long side and between it
and the flat of the inner ring, a small lifting spring is disposed.
On the sprocket wheel or outer element being forwardly rotated for driving,
by the friction contact of the curved outer surface of the wedge (or wedges)
against the inner periphery of the rotating ring, the said wedge is tipped for-
wardly on its fulcrum and also slightly pushed along or advanced in the direc-
tion of its rotation, thereby jambing the wedge between the driving and driven
elements, hence the clutching of the one part to the other for the transmission
of motion. The small spring acts to lift the curved surface of the wedge into
frictional contact with the outer ring and ensure the positive and rapid action
of the clutch.
When the outer ring is held stationary, the wedge is tipped in the reverse
direction, compresses the spring (whose base may be seated in a well in the
inner element) and releases the one part from the other so that the said inner
element--which is fast to the hub, admit of running free within the stationary
sprocket element.
To minimise the friction when the hub is running free, balls may be inter-
posed between the inner and outer parts to run within a race or races formed
41. annosed edges of the said inner and outer elements,

page_text: Where the inner part is to be the driving element, such as in the case of a
clutch arranged in connection with a cycle crank axle for operating a back-
pedalling brake, the positions of the shifting wedge pieces has to be reversed.
Dated this 5th day of October 1899.
DIBUITICATION.
Improvements in Friction Clutches.
I, CHARLES THOMAS BROCK SANGSTER, General Manager of the Cycle Com-
ponents Manufacturing Company. Limited, of Bournbrook, near the City of
Birmingham, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
-
This invention has relation to friction clutches, principally for use in connec-
tion with the free driving wheels and back pedalling brake mechanism of cycles
and motor cycles.
Figure 1 of the accompanying drawing represents a side elevation of the
said friction clutch mechanism, this particular arrangement being designed for
use in connection with the free hub wheel of a bicycle. This view shows the
parts of the said clutch mechanism in the positions they assume when out of
action so as to permit of the hub to which the clutch is fitted running free
within the stationary toothed ring.
Figure 2 is a similar view to that represented in Figure 1, but showing
the clutch in its operative position, i.c. with the tooth ring clutch to the hub
for driving.
Figure 3 is a vertical section of Figure 2 upon the dotted line c.
Figure 4 is an elevation of the toothed wheel or driving ring of the clutch
separately.
Figure 5 represents in side elevation, the other parts of the clutch, viz. the body
or driven part, which is fixed to the wheel hub, and the clutching devices by
which connection is made between the driving and driven elements, when
required.
Figure 6 represents in vertical section, the whole of the component parts of
the clutch separately or disassembled from one another.
Figure 7 represents a portion of the said clutch, showing, upon an enlarged
scale, one of the clutching devices in the position it assumes when the inner or
driven element is running free in the direction indicated by the arrow, the
outer or driving element remaining relatively stationary.
Figure 8 is a similar view to that represented in Figure 7 but the clutching
device is shown in the position it assumes when transmitting motion from the
driving to the driven element, both of which are rotated in the direction indi-
cated by the arrows.
The same letters of reference indicate corresponding parts in the several
figures of the drawing.
In the new or improved clutch action, (in which no rollers or balls or other
loose wearing parts are employed) rocking and sliding wedge elements a, are

page_text: used as the clutching devices, these wedges having their fulcra or centres a¹,
upon which they rock, excentrically situated, both in respect to the said wedges
themselves and (in the case of a free wheel cycle clutch as illustrated in the
drawing) in respect to the centre of the hub upon which the clutch is mounted.
One, two or more of such wedges may be employed, and each of them is located
within a space 6 bounded inwardly by a straight edge part or extended cross
flat c formed on the periphery of the inner disc or driven element c, (which is
secured to the hub of the wheel to be driven) and a portion of the curved inner
periphery d¹ of the outer toothed ring, chain wheel or driving element d. The
space is thus of the figure of a double wedge with a curved outer edge, or of
the segment of a circle, and the outer edge a² of the loose wedge piece is shaped
to conform to the curve of the said space, whilst one flat part 3 of the double
wedge is longer than the other a, with the two flats,, being disposed rela-
tively at a slight angle, thus forming at the junction or meeting point of the
two flats, a crossing or transverse edge which constitutes the excentric fulcrum
whereon the wedge piece may turn or make a rocking movement. Coming
under the long side and between it and the opposite part of the flat of the
inner ring, a small lifting spring e, is disposed, with its base, seated in a well e¹,
in the inner element.
The parts of the clutch are retained in their assigned positions in the form
shown in the drawings, by side rings or cover plates f, g, connected to the inner
or diven element by means of screws h.
0: e sprocket wheel or outer element d, being forwardly rotated for driving,
by the friction contact of the curved outer surface of the wedge (or wedges)
against the inner periphery of the rotating ring d, the said wedge is tipped
forwardly on its fulcrum a, and also slightly pushed or advanced along the
flat c in the direction in which is rotating, or in other words, the wedge is
shifted from the position shown in Figure 6 to that of Figure and is thereby
jambed between the driving and driven elements, hence the clutching of the one
part to the other for the transmission of motion. The small spring acts to lift
the curved surface of the wedge into frictional contact with the outer ring and
ensure the positive and rapid action of the clutch.
When the outer ring is held stationary, the wedge is tipped in the reverse
direction, and releases the driven part e from the driving ring d, so that the
said inner element-which is fast to the hub, admits of running free within the
stationary sprocket element. If desired, the small springs e may be dispensed
with, and the wedges be taken back by friction alone.
To minimise the friction when the hub is running free, balls may be inter-
posed between the inner and outer parts to run within a race or races formed in
the opposed edges of the said inner and outer elements.
Where the inner part is to be the driving element, such as in the case of a
clutch arranged in connection with a cycle crank axle for operating a back-
pedalling brake, the positions of the shifting wedge pieces has to be reversed.
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:-
In friction clutches for use in cycles, the employment as the clutching device.
of one or more wedging elements, such as vt, located between the driving and
driven members of the clutch and within a space such as b, bounded on one
side by a flat or straight part of the outer periphery of the one member, and on
the other side by a portion of the curved inner periphery of the other member,
with the one edge of the wedge piece being shaped to conform to the curved
side of the said space whilst the other edge has a pair of flats, one longer than
the other, arranged at a slight angle relative to one another and with their
meeting ends forming an excentric fulcrum about which the said wedge is
capable of a slight rocking movement within its confining space and also of a

page_text: slight sliding movement into or out of its wedging or clutching position, the
whole being arranged, with or without a lifting or return spring such as e, sub-
stantially as herein described and also as set forth in the accompanying drawing.
Dated this 16th day of May 1900.
CHARLES THOMAS BROCK SANGSTER.
By Henry Skerrett,
24, Temple Row, Birmingham, Agent for Applicant.
CHARLES THOMAS BROCK SANGSTER.
By Henry Skerrett,
24, Temple Row, Birmingham, Agent for Applicant.