Improvements in or relating to Driving Gear for Cycles.
Year: 1897

page_text: Improvements in or relating to Driving Gear for Cycles.
I, CHARLES MONTAGUE LINLEY, Cycle Manufacturer, of 42, St. Luke's Road,
Clapham, in the County of Surrey, do hereby declare the nature of this invention
to be as follows:-
This invention relates to driving gear for cycles, its object being the construc-
tion of driving gear of the ratchet or clutch type in such a manner that whilst
ordinarily permitting the driving gear to over-run the crank shaft so that the
rider may hold his feet stationary on the pedals, simple means are provided for
putting the ratchet or clutch gear out of action so that the driving gear and
pedals become connected to permit the pedals to be used for back-pedalling.
For instance one part of the clutch or ratchet gear fixed on the part that is
to be driven can be arranged to be operated by another part geared to the crank
shaft and loose upon the driven part, becoming coupled to the latter by pawls
or clutches which are operative only when the driving part runs in such a direction
that it will propel the machine forward; for the purposes of reference I will
hereinafter speak of these two parts of the gear as the driving and driven parts
respectively.
According to this invention I provide devices for connecting these parts when
required so that the driving part which is intended normally to be free can be
fixed when desired to its companion or driven part, so as to be able to drive it
in either direction and thus enable back-pedalling to be effected as well as forward
driving.
A convenient locking device is a screw in the driving or free part capable of
being adjusted to cause the ratchet or clutch to engage permanently with the
driven part; preferably this screw is so situated that the action of back-pedalling
subjects it to compression and not to shear; that is to say it can be placed in
a direction tangential to the axis of the part driven. Or a cam may be provided
on one of the two parts adapted to engage with a recess in the other, cam and
recess being so shaped and situated that the former turned into one position
misses the recess, but turned into another position engages therewith and locks
the driving and driven parts together. Or a bolt or sliding clutch may be
employed, carried upon one part and adapted to engage the other when desired.
Or two sets of ratchets or clutches may be used, one set for driving the machine
forward, the other set being so situated as to be adapted to be thrown into
operation in addition to driving the machine backwards, this, latter set being
conveniently engaged with a rotatable slotted or cam disc arranged so as to be
easily operated by the rider to bring them into gear with the driven part and
thus enable it to be operated with equal facility in either direction.
Several of the locking devices hereinbefore referred to may be employed in
company with mechanism by which they can be operated without rendering it
necessary that the rider should dismount,

page_text: Friction clutches or coupling devices may be employed for the purposes of
this invention if desired.
Dotad this 20th day of August 1807
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Driving Gear for Cycles.
I, CHARLES MONTAGUE LINLEY, Cycle Manufacturer, of 42, St. Luke's Road,
Clapham, in the County of Surrey, 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 driving gear for cycles, its object being the construc-
tion of driving gear of the ratchet or clutch type in such a manner that whilst
ordinarily permitting the driving gear to over-run the crank shaft. so that the
rider may hold his feet stationary on the pedals, simple means are provided for
putting the ratchet or clutch gear out of action so that the driving gear and
pedals become connected to permit the pedals to be used for back-pedalling.
For instance one part of the clutch or ratchet gear fixed on the part that is
to be driven can be arranged to be operated by another part geared to the crank
shaft and loose upon the driven part, becoming coupled to the latter by pawls
or clutches which are operative only when the driving part runs in such a direction
that it will propel the machine forward; for the purposes of reference I will
hereinafter speak of these two parts of the gear as the driven and driving parts
respectively.
According to this invention I provide devices for connecting these parts when
required so that the driving part which is intended normally to be free can be
fixed when desired to its companion or driven part, so as to be able to drive it
in either direction and thus enable back-pedalling to be effected as well as forward
driving.
A convenient locking device is a screw in the driving or free part capable of
being adjusted to cause the ratchet or clutch to engage permanently with the
driven part; preferably this screw is so situated that the action of back-pedalling
subjects it to compression and not to shear; that is to say it can be placed in
a direction tangential to the axis of the part driven. Or a cam may be provided
on one of the two parts adapted to engage with a recess in the other, cam and
recess being so shaped and situated that the former turned into one position
misses the recess, but turned into another position engages therewith and locks
the driving and driven parts together. Or two sets of ratchets or
clutches may be used, one set for driving the machine forward the
other set being so situated as to be adapted to be thrown into opera-
tion in addition for driving the machine backwards, this latter set being
conveniently engaged with a rotatable slotted or cam disc arranged so as to be
easily operated by the rider to bring them into gear with the driven part and
thus enable it to be operated with equal facility in either direction.
Friction clutches or coupling devices may be employed for the purposes of
this invention if desired.
In the accompanying drawings
Figure 1 is a view half in section and half in elevation and
Figure 2 a cross section on the line 2-2 of Figure 1 of one construction of
gear according to this invention as applied to the rear sprocket of a bicycle.

page_text: Figure 3 is an elevation showing an alternative construction of coupling
device.
Figures 4 and 5 illustrate a double pawl gear.
Like letters indicate like parts throughout the drawings.
Referring first to Figures 1 and 2 A is the "driving" and B the "driven"
member, A being the rear spocket or rear chain wheel of a bicycle, and B the
portion attached to the hub of the rear or driving wheel.
Provision is made in the example illustrated for so attaching it by the screw
thread B by means of which the part B can be screwed on to the hub. The
driving member A is provided with an extension A' forming a sleeve to encase
the cup-like member B, and carrying a ratchet A³ on its inner circumference
and a ball race A³. A second ball race A is carried on its inner circumference of
the sprocket A.
The driving member comprising the sprocket A, sleeve A¹, ratchet A³ and ball
races or cups A2, A4, is preferably formed of one piece of steel.
The driven member B carries at one end a flange B³ forming with the cup A²
the complete run for one set of balls, and at the other end, upon the disc-like
portion B5 of its periphery, projections B³ and a tubular extension B', the latter
serving to carry a disc C.
The edge of the disc C constitutes the "cone" which with the cup A forms
the ball bearing at that end of the sprocket sleeve. The projections B³ serve
as a backing or support for the pawls D the pivots D₁ of which are supported
at one end in the holes B6 in the face B³ at the base of the projections B2, and at
the other in holes C¹ in the disc C.
The pawls D may be kept to their work by springs if desired, spiral springs
for that purpose being shown at E.
The coupling device is constituted by a screw F fitting in a boss A³ on the
sleeve A¹ and so arranged that when screwed inwards towards the driven part B
the tip of the screw engages a recess B6 therein. The screw is preferably
arranged with its axis in a direction substantially tangential to the axis of rota-
tion of the part B so that the screw may be subjected to a thrust rather than
to shear stress.
When the screw is sufficiently withdrawn the part A will, when rotated by the
chain in the direction indicated by the arrow 1, drive the part B in the same
direction through the pawl and ratchet gear but the part B will be free to
overrun the part A, thus enabling the rider to keep his feet stationary on the
pedals while going forward by momentum or downhill.
If the screw F, on the other hand, be entered through the sprocket sleeve as
shown in Figures 1 and 2 sufficiently far to engage the recess B6 the part B will
be prevented by it from over-running the part A, and, the pawls preventing
relative rotation between the said parts in the other direction, the two will be-
come in effect locked together. If preferred a projection may take the place of
the recess B6.
The alternative coupling device illustrated in Figure 3 is formed by cams G,
carried by the sprocket and adapted when turned into one position to engage
recesses B7 formed upon the flange B³ or on projections thereon or attached
thereto. When turned in another position, the cams miss the recesses and the
driven part B can overrun the driving part A.
One of the cams G is shown in the drawing turned into the coupling position
the other two being in the free position. The cams may be secured in any
convenient manner in the desired position. Preferably they are secured to
pins which are rotatably carried by the sprocket and which are provided with
flats against which springs bear and secure them against undesired rotation in
a well-known manner.
Provision for rotating the cams is made, in the examples shown, by slots by
means of which they may be rotated with the aid of a screwdriver or the like.
The construction according to which the coupling is effected by a second set

page_text: of pawls is illustrated in Figures 4 and 5, Figure 4 showing them in the free
and Figure 5 in the coupling position. The additional pawls are there marked H
and the teeth of the ratchet carried by the sprocket are so formed as to serve
to engage both sets. of pawls.
The forward driving pawls D operate as already described with reference to
Figs. 1 and 2 but the pawls H are arranged to be thrown in or out of action as
desired. This is effected in the example illustrated by providing the pawls H
with pins H which project into and engage with cam slots in the disc C so
that clockwise rotation of the disc through a small angle relatively to the pawls H
imparts an inward radial motion to the pins and thus throws the pawls out of
engagement as they are shown in Figure 4, whereas a rotation of the disc in
the opposite direction puts them in the coupling position as shown in Figure 5.
It may be remarked that although the "pawls" H are in the shape of pawls
and are conveniently so described, they merely perform the function of a
coupling and are not required to act in the manner in which pawls are usually
employed and in which the pawls D operate.
A set screw M is provided by which the disc C can be secured in either of its
extreme positions, holes N1 N2 being provided in the face B5 for the reception
of the end of the screw M.
The lock nut L shown in Figures 1 and 2 which secures the disc C upon the
projection B may be made smaller for the construction shown in Figures 4
and 5 from which it is omitted for the sake of clearness.
The outer ends of the pawl pivots will in the construction shown in Figures 4
and 5 not enter the disc C as the latter must be rotatable through the angle
necessary to operate the pawls H.
Backing or support for the pawls D and H as shown at B³ in Figure 1 may
be provided if desired.
.
Various modifications may without departing from the spirit of this invention,
obviously be made in the constructions described and illustrated.
For instance whereas the pawls have been shown on the driven and the ratchet
on the driving part they may be arranged vice versa. Or in the construction
shown in Figs. 4 and 5 the slots C2 may be carried by an additional disc and the
disc C provided with slots to provide for the travel of the pins H' and one end
of the pawl pivots may then he carried as before by the disc C.
Or instead of the pawls D and H engaging the same set of teeth separate sets
may be provided one for each set of pawls or other cam surfaces than those
formed by the slots C may be employed, or the cams may be replaced by links.
Or the parts constituting the respective coupling devices may be interchanged
as regards their disposition on the driven and driving members of the gear.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination with a ratchet driving gear for a cycle or the like com-
prising a driving part and a driven part of a coupling device formed by a screw F
on one part and a recess or projection 136 on the other part substantially as
described.
2. The combination with a ratchet driving gear for a cycle or the like of a
coupling screw F having its axis substantially tangential to the axis of rotation
of the gear substantially as and for the purpose described.
3. The combination with a ratchet driving gear for a cycle or the like com-
prising a driving part and a driven part of a coupling device formed by a cam G
on one part and a recess B7 on the other part substantially as described.
4. The combination with a ratchet driving gear for a cycle or the like com-
prising a driving part and a driven part of a coupling device formed by one or
more pawls H on one part and teeth on the other part substantially as described.
5. The combination with a ratchet driving gear for a cycle or the like com-

page_text: prising a driving part and a driven part of a coupling device formed by one or
more pawls H which are thrown in or out of action by cams or links carried
by a movable disc C.
6. In a coupling device such as is described in Claim 5 the combination with
the disc C of a locking device to secure it in either of its extreme positions.
7. The combination and arrangement of parts constituting the complete
ratchet driving gear and coupling device for a cycle or the like substantially as
described and illustrated in Figures 1 and 2 or Figure 3 or Figures 4 and 5 of
the accompanying drawings.