Improvements in or relating to the Driving Gear of Autocars.
Year: 1898

page_text: Date of Application, 7th Dec., 1898
Complete Specification Left, 7th Sept., 1899-Accepted, 28th Oct., 1899
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Driving Gear of Autocars.
I, JOHN KEMP STARLEY, Managing Director of the Rover Cycle Co. Ltd.,
Meteor Works, Garfield Road, Coventry, Warwickshire, do hereby declare the
nature of this invention to be as follows:-
My invention relates to the driving gear of autocars, which commonly com-
prises two chains running over two small sprocket pinions mounted on an
intermediate shaft and two large sprocket wheels mounted on the driving road
wheels. The intermediate shaft is also provided with one or more belt pulleys
and is mounted in bearings usually three in number, one near each end and one
near the centre thereof. In order to tension the chains these bearings are
moved on the brackets by which they are connected to the frame of the vehicle,
and it will be readily understood that moving the bearings to adjust the chains
necessitates the adjustment of the belts also. The sprocket pinions are generally
made of very short radius in order to obtain the necessary reduction of speed
between the motor and the driving road wheels, but this smallness of the sprocket
pinions necessitates very sharp bending of the joints of the chains, and this
takes place at a high speed as the chains pass round the said sprocket pinions.
These conditions are very unfavorable to the satisfactory working of the chains
and give rise to an unpleasant noise when the gear is in action. Consequently
the present invention has for its objects to provide means for adjusting the chains
in an easy manner and without interfering with the tension of the belts, to
avoid the excessive bending of the chain and to reduce the noise above
referred to.
To attain these objects, I replace each sprocket pinion by a spur toothed
pinion, and on a suitable stud or axle I mount an internally and externally
toothed wheel of say three times the diameter of the spur pinion. The internal
teeth of the said wheel are adapted to mesh with the teeth of the spur pinion,
and the external teeth are adapted to mesh with the links of the chain, the
said chain passing around the said internally and externally toothed wheel.
The links of the chain necessarily bend to much less sharp angles in passing
round this wheel than in passing round the usual small sprocket pinion.
To provide for the adjustment of the chain, I adapt the stud or axle on which
the internally and externally toothed wheel is mounted, to be moved in a curve
struck from the axis of the intermediate shaft as centre. This may be carried
out in various ways. For example, the case of the bearing carrying the end
of the intermediate shaft may be extended downwards as a plate or bracket.
In this plate is formed the transverse, curved slot through which
passes a stud carrying the wheel on ball bearings. The stud is bolted
in place and is adjusted by a draw screw passing through a projection on the
plate and provided with a nut beyond the projection. To tighten the chain,
the nut or nuts on the stud are released and the nut on the draw screw rotated
until the distance between the sprocket wheels is increased as much as required,
when the stud nut or nuts is or are re-tightened and the adjustment locked.

page_text: Whether the wheel be moved by these particular means or not, it will be
observed that the adjustment of the chain does not involve any change in the
position of the intermediate shaft and hence does not interfere with the tension
of the belt or belts. The necessity of moving the bearings carrying the inter-
mediate shaft is avoided and the two chains may be adjusted independently.
In order to reduce the strain on the wheel and pinion and their bearings, I
arrange the axes of the said wheel and pinion in or approximately in a line
drawn at right angles to the driving run of the chain from the end thereof, and
place the axis of the spur pinion between the axis of the wheel and the end of the
driving run of the chain, so that the power and resistance are applied to the
internally and externally toothed wheel at points thereon as near together as
possible. As the positions of the parts are subject to alteration in adjusting the
chain, I prefer to so arrange the parts that the mean position allowed by the
chain adjusting device is that above described.
It will be obvious that my invention may be applied to chain gearing for
autocars arranged in other positions than that above described, and to gearing
in which belts and pulleys are substituted for the above mentioned chains and
Sprocket wheels or vice versa.
Improvements in or relating to the Driving Gear of Autocars.
I, JOHN KEMP STARLEY, Managing Director of the Rover Cycle Company,
Limited, Meteor Works, Garfield Road, Coventry, Warwickshire, 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 relates to the driving gear of autocars, which commonly com-
prises two chains running over two small sprocket pinions mounted on an
intermediate shaft and two large sprocket wheels mounted on the driving road
wheels. The intermediate shaft is also provided with one or more belt pulleys
and is mounted in bearings usually three in number, one near each end and one
near the centre thereof. In order to tension the chains these bearings are
moved on the brackets by which they are connected to the frame of the vehicle,
and it will be readily understood that moving the bearings to adjust the chains
necessitates the adjustment of the belts also. The sprocket pinions are generally
made of very short radius in order to obtain the necessary reduction of speed
between the motor and the driving road wheels, but this smallness of the sprocket
pinions necessitates very sharp bending of the joints of the chains, and this
takes place at a high speed as the chains pass round the said sprocket pinions.
These conditions are very unfavorable to the satisfactory working of the chains
and give rise to an unpleasant noise when the gear is in action. Consequently
the present invention has for its objects to provide means for adjusting the chains
in an easy manner and without interfering with the tension of the belts, to
avoid the excessive bending of the chain, and to reduce the noise above
referred to.

page_text: And in order that my invention may be properly understood I will describe the
same with the aid of the accompanying drawings, wherein,
Figure I is a side elevation, and
Figure II is a transverse section on the line a-a in Figure I.
Like numerals indicate like parts in both figures.
I replace each of the usual sprocket pinions by a spur toothed pinion 2, and
on a suitable stud axle 3, I mount an internally and externally toothed wheel 4
of say three times the diameter of the spur pinion. The internal teeth 5 of the
wheel 4 are adapted to mesh with the teeth of the spur pinion 2, and the external
teeth 6 of the wheel 4 are adapted to mesh with the links of the chain 7, the
said chain passing round the said internally and externally toothed wheel 4.
The links of the chain necessarily bend to much less sharp angles in passing
round this wheel 4 than in passing round the usual small sprocket pinion.
To provide for the adjustment of the chain, I adapt the stud axle 3, on which
the internally and externally toothed wheel 4 is mounted, to be moved in a curve
struck from the axis of the intermediate shaft S as centre. This may be carried
out in various ways. In the arrangement shown in the drawings, the case 9 of
the bearing 10 carrying the end of the intermediate shaft 8 may be extended down-
wards as a plate or bracket 11. In this plate is formed the transverse curved slot 12
through which passes the stud 3 carrying the wheel 4 on ball bearings. The
stud is bolted in place and is adjusted by a draw screw 13 passing through a right
angle projection 14 on the plate and is provided with a nut 15 beyond the pro-
jection. To tighten the chain, the nut 16 on the stud 3 is released and the nut 15
on the draw screw 13 is rotated until the distance between the sprocket wheels,
around which the chain 7 runs, is increased as much as required, when the stud
nut 16 is re-tightened and the adjustment locked. The nut 17 is used to lock
the adjustment of the ball bearings of the wheel 4.
Whther the wheel 4 be moved by these particular means or by any other
arrangement comprising the curved movement of the stud axle 3, it will be
observed that the adjustment of the chain does not involve any change in the
position of the intermediate shaft 8 and hence does not interfere with the tension
of the belt or belts running over the pulleys mounted thereon. The necessity
of moving the bearings 10 carrying the intermediate shaft is avoided, and the
two chains may be adjusted independently.
In order to reduce the strain on the wheel 4 and pinion 2 and their bearings,
I arrange the axes of the said wheel and pinion in or approximately in a line
drawn at right angles to the driving run of the chain from the end 18 of such
run, and place the axis of the spur pinion 2 between the axis of the wheel 4
and the said end 18 of the driving run of the chain, so that the power and
resistance are applied to the internally and externally toothed wheel 4 at
points thereon as near together as possible. As the positions of the parts are
subject to alteration in adjusting the chain, I prefer to so arrange the parts
that the mean position allowed by the chain adjusting device is that above
described.
It will be obvious that my invention may be applied to chain gearing, for
motor cars arranged in other positions than that above described, and to gearing
in which belts and pulleys are substituted for the above mentioned chains and
sprocket wheels or vice versa.
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. In driving gear for autocars, the combination and arrangement of parts
adapted to operate substantially as herein described and as illustrated by the
accompanying drawings.
2. In driving gear for autocars, the combination of a rotatable shaft, a spur
pinion fixed to such shaft, a stud adapted to be moved about such shaft as

page_text: centre, an internally toothed wheel mounted on the said stud and gearing with
the said spur pinion and a flexible transmitting member engaging with the
periphery of the said internally toothed wheel, substantially as and for the
purpose set forth.
3. In driving gear for autocars, the combination of a rotatable shaft, a spur
pinion fixed to such shaft, a stud adapted to be moved about such shaft as
centre, an internally toothed wheel mounted on the said stud and always gearing
with the said spur pinion, means for transmitting motion from the periphery
of the said internally toothed wheel and means for moving and fixing the said
stud, for the purposes set forth.
4. In driving gear for autocars, the combination of a rotatable shaft, a spur
pinion fixed to such shaft, an internally toothed wheel gearing with the said
spur pinion, a flexible transmitting member engaging with the periphery of the
said internally toothed wheel, a stud adapted to carry the said internally toothed
wheel situated in or approximately in a line passing through the axis of the
spur pinion and standing at right angles or approximately at right angles to
the end of the driving run of the flexible transmitting member, for the purpose
set forth.
as
5. In driving gear for autocars, the combination of a rotatable shaft, a spur
pinion fixed to such shaft, a stud adapted to be moved about such shaft
centre, an internally toothed wheel mounted on the said stud and gearing with
the said spur pinion, a fixed plate, there being a transverse slot in the said
plate curved with the axis of the said shaft as centre and adapted to carry the
said stud, an apertured right angle projection on the said plate, a draw screw
engaging the said stud and passing through the said projection, an adjusting
nut on the said draw screw and a lock nut on the said stud, substantially as
and for the purpose set forth
Dated this 6th day of September 1899.
DOUGLAS LEECHMAN, M. Cy. E.I.,
Fellow of the Chartered Institute of Patent Agents,
18, Hertford Street, Coventry,
9, Exchange Chambers, New Street, Birmingham, and
75, Chancery Lane, London, W.C.,
Patent Agent for the Applicant.