Year: 1898

page_text: I, EDMUND HUGH HODGKINSON, of 8, Lancaster Gate, in the County of Middle-
sex, Gentleman, do hereby declare the nature of this invention to be as follows:-
-
According to this invention a self binding spring clutch consists of a thin steel
or other suitable spring band attached by one end to the driving part and lapped
around the shaft to be driven or vice versa, that is, the shaft may be the driving
part.
This band is wound upon itself around the shaft and it has a tendency to
close itself and embrace the shaft. A forward movement of the driving part
immediately causes the band to bind upon itself and on the shaft and so furn
the latter. Whilst on the other hand immediately the driving part stops, the
forward movement of the shaft has a tendency to uncoil the band and the shaft
can itself run forwards freely.
In some cases rollers are placed between the laps of the band. The first roller
is kept in position by a projection on the band and the other rollers are held at
suitable distances apart by distance blocks.
The end of the band is either attached directly to the driving part or to a link
which is attached to the driving part, so that when the driving part moves forward
the band is assisted to bind on the shaft by the toe of the link pressing it against
the shaft.
If necessary the band may be covered with leather to assist it to bind.
These spring clutches are especially applicable for velocipedes and auto-motor
carriages for transmitting motion only in one direction so that for instance the
pedals can be stopped when desired.

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement: —
.
According to this invention a self binding spring clutch consists of a thin steel
or other suitable spring band attached by one end to the driving part and lapped
around the shaft to be driven or vice versa, that is, the shaft may be the driving
part.
This band is wound upon itself around the shaft and it has a tendency to
close itself and embrace, the shaft. A forward movement of the driving part
immediately causes the band to bind upon itself and on the shaft and so turn
the latter. Whilst on the other hand immediately the driving part stops, the
forward movement of the shaft has a tendency to uncoil the band and the shaft
can itself run forwards freely.
In some cases rollers are placed between the laps of the band. The first roller
is kept in position by a projection on the band and the other rollers are held at
suitable distances apart by distance blocks.
The end of the band is either attached directly to the driving part or to a link
which is attached to the driving part, so that when the driving part moves forward
the band is assisted to bind on the shaft by the toe of the link pressing it against
the shaft.
If necessary the band may be covered with leather to assist it to bind.
These spring clutches are especially applicable for velocipedes and auto-motor
carriages for transmitting motion only in one direction so that for instance the
pedals can be stopped when desired.
The accompanying drawings show so much of my improved apparatus as is
necessary to illustrate the subject-matter herein claimed.
Figure 1 is a vertical transverse section through the clutch; Figure 2 a
corresponding view of a modification thereof. Figure 3 shows the clutch applied
to a sprocket wheel.
The figures show a shaft a, with a band 6 lapped around it but unsecured
thereto. The outer end of the band may be either attached directly to the
driving part or may be pivotted on a triangular link or elbow lever d, attached
to the driving part at its upper corner e, so that when the driving part moves
forward the band is assisted to bind on the shaft by the toe f of the link pressing
it against the shaft, the link d, as will be seen, thus constituting a friction or
pressure brake.
In Figure 3 the driving part is shown as consisting of a sprocket wheel A,
provided with a luga, to which the elbow lever d is pivotted.
Figure 2 shows an organization of parts similar to that shown in Figure 1,
with the addition of rollers g, placed between the inner laps of the band. The
first roller is kept in position by a projection h on the inner end of the band, and
the other rollers are held at a suitable distance apart by spacing blocks 2. These
rollers cause the clutch to act more quickly, pressing the inner convolution against
the shaft, while the outer convolutions in tightening move freely on the rollers,
thus diminishing friction.
Figure 4 shows a modification of a clutch in which the inmost convolution of the
spring band has upon it thickening pieces or supports , these supports prevent
the spring band from kinking.
It has also been found in practice that good results are obtained by providing
springs which always tend to press the rollers g onto the projection h.
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, substantially as hereinbefore set forth, of a driving part,
a driven part, and a coiled spring having its outer end attached to one part, its
convolutions being wound upon themselves, and its inmost convolution encircling
but not attached to the other part.

page_text: 2. The combination, substantially as hereinbefore set forth, of a driving part,
a driven part, a link, and a coiled spring having its outer end attached to the
link, its convolutions being wound upon themselves, and its inmost convolution
encircling but not attached to one of the parts.
3. The combination, substantially as herein before set forth, of a driving part,
a driven part, a coiled spring having its outer end attached to one part, its con-
volutions being wound upon themselves, and its inmost convolution encircling but
not attached to the other part, and rollers interposed between said convolutions to
diminish friction and quicken the action of the clutch.
4. The combination, substantially as hereinbefore set forth, of a driving part,
a driven part, a link or friction brake, a coiled spring having its outer end attached
to the link, its convolutions being wound upon themselves, and its inmost con-
volution encircling but not attached to one of the parts, and rollers interposed
between said convolutions, for the purposes specified.
Doted this 3rd day of April 1890