Improvements in Change-Speed Gear for Motor-cars and other purposes.
Year: 1898

page_text: Date of Application, 12th Nov., 1898
Complete Specification Left, 11th Sept., 1899-Accepted, 14th Oct., 1899
PROVISIONAL SPECIFICATION.
Improvements in Change-Speed Gear for Motor-cars and
other purposes.
We, FREDERICK COOPER, of The Retreat, Albany Park, Kingston, in the County
of Surrey, and THOMAS RUSHFORTH MARRIOTT, of Monkswood House, London
Road, St. Albans, in the County of Herts, Managers of Cycle Depôt do hereby
declare the nature of this invention to be as follows:-
The invention relates to improvements in change-speed gear for motor-cars
and other purposes, particularly where positive clutches are used or toothed
wheels moved in or out of engagement.
In either of these cases it is desirable to use in conjunction with the positive
gear, a slipping friction clutch or belt by which the load is released while the
change is being effected.
According to our invention we provide a cam or cams which is or are capable
of acting on both positive and slipping mechanism, causing them to move in such
a way that the load is released while the change of the positive gear is being
effected.
According to one method of carrying our invention into effect, we employ a
plate having two cam grooves, each containing a roller, one roller being connected
to a cone or friction clutch which drives a sleeve carrying a set of gear wheels
on its own shaft, and the other connected with a sleeve which passes through a
corresponding set of wheels on an adjacent shaft and is provided with projec-
tions which engage with indentations in the wheels, thus fixing each to its shaft
alternately at it passes through.. The plate is placed in the plane of the axis of
the two shafts, and its grooves are cut so that the movements of the positive and
slipping clutches are in harmony with the before-mentioned principle.
We do not however limit ourselves to this particular construction, as the
principle of operation can be carried out in a variety of ways.
Improvements in Change-speed Gear for Motor-cars and
other purposes.
We, FREDERICK COOPER, of The Retreat, Albany Park, Kingston, in the County
of Surrey, and THOMAS RUSHFORTH MARRIOTT, of Monkswood House, London
Road, St. Albans, in the County of Herts, Managers of Cycle Depot, do hereby
declare the nature of this invention and in what manner the same is to be per-

page_text: formed to be particularly described and ascertained in and by the following
statement:-
The invention relates to improvements in change-speed gear for motor-cars
and other purposes, particularly where positive clutches are used or toothed
wheels moved in or out of engagement.
In either of these cases it is desirable to use in conjunction with the positive
gear, a slipping friction clutch or belt by which the load is released while the
change is being effected.
According to our invention we provide a cam or cams which is or are capable
of acting on both positive and slipping mechanism, causing them to move in such
a way that the load is released while the change of the positive gear is being
effected.
One method of carrying our invention into effect is represented in the accom-
panying drawings, in which:
Fig. 1 is a longitudinal section, Fig. 2 is a cross section drawn on the line A--B
Fig. 1, and Fig. 3 is a view of the cams developed in a plane.
a is the driving shaft (which may be direct from the engine or a counter
shaft). On this shaft are keyed a pair of wheels a¹, a³, which gear into a pair of
wheels b, c, provided with clutches b, c, on the sides, the wheel b running loose
on the shaft d and the wheel c running loose on the sleeve e.
The sleeve e has a clutch e* on the inner end thereof, which engages with the
clutches b, c, on either of the wheels b, c; this arrangement constitutes the
positive clutch.
The wheels a', a², b, c, are enclosed in a metal gear case f, which has a pro-
jection f¹ on one side thereof; on this projection fi is fitted a cam drum g which
has two cam grooves g¹, 92, the groove g¹ being for the positive clutch and g² for
the friction clutch. These grooves are so shaped and arranged that the positive
clutch is fully in position or gear before the friction clutch comes into action,
thereby avoiding all shocks.
On the positive clutch sleeve e is fitted a ball race e¹ with a projection e² on each
side passing through slots in the projection f¹ of the gear case f to keep the
ball race e in position; these projections e² also pass into the cam groove g¹ to
give the necessary motion.
On the outer end of the positive clutch sleeve e is fitted a friction clutch bell h
capable of sliding on keys e, and this friction clutch bell h is also fitted with a
ball race similar to the sleeve ball race e¹ and provided with projections h
passing into the cam groove 93. On the counter shaft & is fitted the male
friction clutch ³, which is capable of sliding on keys d' and is yieldingly kept
in position by the spring i on the back.
The working of this change speed gear is effected by pulling over the rocking
lever g³ attached to the cam drum g; in this way the cam is revolved in one or
the other direction, thereby giving motion to the positive clutch and putting it
into gear with either the gear wheel b or the gear wheel c. As soon as the
positive clutch is in gear, the friction cam groove & forces the friction bell h on
to the male portion h³ against the spring i, thereby causing motion to be com-
municated to the counter shaft d.
The spring i is to avoid sudden shocks when forcing the friction clutch into
working position, also to allow for wear of the clutch and cam grooves.
We would here remark that we do not confine ourselves to the particular con-
struction of change speed gear herein shown and described, as the principle of
operation can be, carried out in a variety of ways.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
A change-speed gear comprising a positive clutch and friction clutch arrange-

page_text: ment and a cam or cams so arranged as to be capable of acting on both positive
and friction clutches in such way that the load is released while the change of
positive gear is being effected.
Dated this 11th day of September 1899
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.