Improvements in Driving Gear for Velocipedes.
Year: 1892

page_text: Date of Application, 9th Nov., 1892
Complete Specification Left, 1st July, 1893-Accepted, 12th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Driving Gear for Velocipedes.
WILLIAM DEVOLL Cuba Villa Chester Road Erdington in the County of
Warwick Engineer do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to provide a suitable gear for the purpose of
propelling bicycles without the use of chains and chain wheels which are much
objected to on account of the frequent stretchings and slipping of the chains.
For this purpose I fix two cranks on the axle of the rear wheel or driving wheel,
one on each end of the axle outside of the frame or fork which in this case carries
the axle bearings. In a suitable bracket which is attached to the lower part of the
frame underneath the back bone I place a spur wheel and a pinion in a line with
each other but not in gear, and between them I place an intermediate wheel or
carrier, so as to cause the pinion to revolve in the same direction as the spur wheel.
The wheel, pinion, and carrier are placed inside the bracket, the depending sides of
which, form the bearings for the three spindles which pass through the bracket.
The spur wheel and pinion, are keyed on, or otherwise secured to their spindles,
the carrier revolving loose on its own spindle. On the ends of the pinion spindle,
outside the bracket bearings, I fix two cranks of the same stroke as the two cranks
on the driving wheel.
The four cranks are fitted with suitable crank-pius, and are coupled together by
two light coupling rods, one on each side of the driving wheel.
The cranks may be fixed to work at right angles to each other, to overcome dead
centres, or otherwise. The pedal cranks are fitted on the ends of the spur wheel
spindle.
When a forward motion is given to the pedal cranks by the rider, the spur wheel,
which is in gear with the carrier will cause the pinion to revolve in the same
direction, and by means of the cranks and coupling rods, which are connected to the
pinion spindle, the driving wheel will also be propelled forward.
Dated this 8th day of November 1892.
WILLIAM DEVOLL.
COMPLETE SPECIFICATION.
Improvements in Driving Gear for Velocipedes.
I, WILLIAM DEVOLL of Cuba Villa, Chester Road, Erdington in the County
of Warwick Engineer, 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 :-
The object of my invention is to provide a suitable gear for the purpose of
propelling bicycles without the use of chains and chain wheels which are much
objected to on account of the frequent stretching and slipping of the chain.
The accompanying drawings represent the arrangement and construction of a
bicycle according to this invention.
Fig. 1 is a side elevation of what is known as a safety bicycle provided with my
improvements.
Fig. 2 is a side elevation of the bracket and driving gear with coupling rods
removed.
Fig. 3 is an end elevation of the same.

page_text: Fig. 5 is a sectional detail shewing the manner of attaching the bracket to the
frame by a socket connection.
Fig. 6 is a front elevation shewing another method of attaching bracket to the
frame by a flange joint with bolts and nuts.
Fig. 7 is an elevation shewing how bracket may be made in two parts and bolted
together.
Fig. 8 is a plan of the same.
Fig. 9 is a plan shewing driving gear connected to rear or driving wheel.
For this purpose I fix two cranks A A on the axle of the rear wheel or driving
wheel B one on each end of the axle outside of the frame or fork C. C. which in
this case carries the axle bearings. In a suitable bracket D which is attached to
the lower part of the frame underneath the back bone in the manner shewn at E in
Figures and 5 or as shewn at Fig. 6 I place a spur wheel F and a pinion G in a
line with each other but not in gear, and between them I place an intermediate
wheel or carrier H so as to cause the pinion to revolve in the same direction as the
spur wheel.
'
The wheel F, pinion G and carrier H are placed inside the bracket D, the
depending sides of which form the bearings for their three spindles which pass
through the bracket.
The spur wheel F and pinion G are keyed on or otherwise secured to their
spindles the carrier H revolving loose on its own spindle. On the ends of the
pinion spindle outside of the bracket bearings I fix two cranks I, I, of the same
stroke as the two cranks A, A, on the driving wheel. The four cranks are fitted
with suitable steel crank pins J. J. and are coupled together by two light steel
coupling rods K. K. one on each side of the driving wheel in the manner shewn at
Figures 1 and 7.
The cranks may be fixed to work at right angles to each other to overcome dead
centres or otherwise. The pedal cranks are fitted on the ends of the spur wheel
spindle in the usual way.
When a forward motion is given to the pedal cranks by the rider, the spur wheel
which is in gear with the carrier will cause the pinion to revolve in the same
direction and by means of the cranks and coupling rods which are connected to the
pinion spindle, the driving wheel will also be propelled forward.
The piece or fitting O Fig. 5 may be made of malleable iron or steel and
brazed in the tubes forming the frame in the usual way. The shank of it, should
be turned and the socket P bored to fit. The bracket is then secured by tightening
up the two set pins R. R.
Instead of the socket joint, if preferred the bracket may be bolted to the frame in
the manner shewn at Fig. 6. but in this case elongated bolt holes or slots should be
formed in one of the flanges.
The bracket can then be instantly adjusted until the crank axle of the bracket is
parallel with the axle of the driving wheel and is then secured by tightening up the
bolts, and the bracket which has a socket connection may also be readily adjusted
and then secured by the set pins.
The advantage of a simple and ready means of adjusting the bracket is obvious
to competent persons as the smooth and easy working of the cranks and coupling
rods depends on the crank axles being dead parallel.
For facility in moulding the bracket may be made in two parts if preferred and
bolted together in the manner shewn at Figures 7 and 8.
With a bracket as described and shewn any proportion of gear wheels may be
used the proportion shewn in the accompanying drawings being as two of the pinion
to one of the spur wheel the rear wheel or driving wheel thus making two
revolutions to one of the pedal crank axle. The bracket should be made of cast
steel or malleable iron.
The stay rods L L are in two parts and each rod is joined together by a screw
coupling M M. One end of the rods is bolted to the frame or fork C. C. and the
other end to the snugs S on the bracket.

page_text: By means of the screw couplings M. M. the stay rods can be readily lengthened
or shortened a little either way or on either side, so that by this means the distance
between the centres of the two crank axles can be exactly adjusted, as the frame or
fork C. C. is pivotted at the top and free to move.
The carrier spindle N Fig. 3 is shewn hollow to hold a supply of oil; a small
hole is drilled in the middle of it on the underside through which oil runs out to
lubricate the carrier. In place of this a solid spindle may be used if preferred. In
the accompanying drawings plain bearings are shewn for the driving gear; these
should be of steel and hardened. Ball bearings may be used if preferred; the
manner of fitting these is well understood by competent persons.
By the use of single cranks on the outside of the bracket bearings the gear can
be arranged within the bracket and is thus self contained. It is obvious that the
driving gear can thus be made and sold separately apart from the bicycle as by
means of the adjustable connection on the top of the bracket it can be readily
connected and adjusted.
It is obvious that my improvements can also be applied to tricycles by forming
two cranks in the axle of the rear wheels or driving wheels, corresponding with, and
coupled to, the cranks on the pinion spindle in the bracket D, the manner of doing
this is well understood by competent persons in the trade without further
drawings.
By the use of my improvements berein described and illustrated by the
accompanying drawings I am enabled to dispense with chain driving gear and its
adjustments and as by this arrangement any proportion of spur gear may be used so
any desired speed usual in velocipedes can be attained.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. In a bicycle or other velocipede the combination of the bracket D with the
central spur driving gear F. G. H and crank axle fitted with the outside driving
cranks I. I. substantially as described and for the purpose set forth with reference
to Figures 1 to 8 inclusive.
2. In a bicycle or other velocipede the arrangement and combination of parts
substantially as and for the purpose set forth with reference to Figures 1 and 9.
Dated this 29th day of June 1893.
WILLIAM DEVOLL.