Improvements in Driving-gear for Bicycles and other Velocipedes.
Year: 1898

page_text: Date of Application, 19th July, 1898
Complete Specification Left, 19th Apr., 1899-Accepted, 20th May, 1899
Improvements in Driving-gear for Bicycles and other Velocipedes.
I, ARTHUR THOMAS COLLIER, of Gonvena, St. Albans, in the County of Herts,
Engineer, do hereby declare the nature of this invention to be as follows:---
My invention relates to driving-gear for velocipedes, of the kind or class
wherein compound cranks are employed so that a greater leverage will be
obtained during the downward or operative movement of the crank than during
the upward or return movement thereof.
And my said invention relates more particularly to driving-gear such as 1
have described in the Specification of former Letters Patent granted to me and
dated 21st May 1896, No. 11105, in which the variation of the leverage is brought
about by means of an eccentric lever which comprises a strap that turns about
a stationary disc fixed to the frame of the machine so that it is eccentric to the
driving-shaft, and which is coupled to a slide-block or head in which works the
crank-arm or concentric lever.
The chief object of my present invention is to so construct the said driving-
gear that the twisting or torsional stress to which the parts are subjected
when pressure is applied to the pedal, will not be liable to increase the friction
between the crank-arm or concentric lever and the slide-block or head.
For this purpose I make the upper and under surfaces of the said crank-arm
or concentric lever curved in transverse section in such a manner that the curves
form part of a circle the centre of which coincides with the centre of the said
arm or lever; and I provide the said slide-block or head with rollers that bear
against the upper and under surfaces of the said crank-arm or concentric lever,
which rollers are mounted on ball-bearings constructed and arranged as herein-
after mentioned, and are made with peripheral grooves which are curved in
transverse section to correspond to the curved edges of the said crank-arm; and
I so construct the parts that there is sufficient space between the sides of the
crank-arm or concentric lever and the walls of the slide-block to obviate any
liability to friction between these parts. When the driving-gear is thus con-
structed, no increase of friction can take place between the crank-arm and
the slide-block by reason of any twisting or torsional stress due to pressure on the
pedal, the bearing surfaces always being in the same relation to each other. The
twisting of the slide-block is, moreover, restricted by the connection of the same
to the eccentric strap and the fixing of the eccentric as hereinafter mentioned.
The ball-bearings for the said rollers comprise balls running in V-shaped or
other suitable grooves formed in the sides of the said rollers, and in corresponding
grooves formed in the inner sides of the walls of the slide-block, which is made
in two parts, being divided longitudinally, preferably in a central vertical plane.
The said grooves in the rollers and in the slide-block or head can be readily
formed by means of a cutter mounted in a rotary mandrel which is introduced
into a hole in the roller or in the wall of the slide-block or head as the case
may be.
I find it advantageous to make the slide-block or head from two solid

page_text: pieces of steel of one-half the thickness of the said slide-block, and to form in the
said pieces suitable recesses to receive the aforesaid rollers, and suitable slots to
permit the said crank-arm or concentric lever to pass through the said slide-
block.
40
I fix the pedal-pin in a lug or eye formed on the top of the slide-block or on
the front end of the same at or near the top thereof; and on the rear end of the
said slide-block at or near the bottom thereof I form another lug or eye whereby
it is coupled to the eccentric strap. The coupling of these parts is effected by
means of a pin provided with a bearing cone, which is fixed in a lug or eye on
the eccentric strap and works in the rear lug or eye on the slide-block, two series
of balls being arranged between this eye and the said pin, and a cone, which
forms the outermost bearing surface, being screwed upon the end of the said pin
and secured in place by a lock-nut or other convenient means.
To effectually ensure rigidity of the stationary discs or eccentrics, I not only
attach the same rigidly to a clamp fixed on the frame of the machine, but I also
connect them together by means of a bridge-piece or stay so constructed as to be
clear of the chain-wheel when such is employed, and I further provide the
eccentric at one side of the crank-bracket with a socket or with a hollow pro-
jection that encircles the pedal-shaft and fits over a projection or into a socket
formed on the adjustable cone of the ball-bearing on that side of the crank-
bracket. I also provide a ball-bearing between the other eccentric and the pedal-
shaft so that the said shaft will serve efficiently as a support for the said
eccentric.
By these means undue twisting of the slide-block relatively to the crank-arm
or concentric lever is effectually prevented.
It will be seen from the foregoing description that the crank-arm or concentric
lever cannot be subjected to the twisting or torsional stress due to pressure on the
pedal, and that the twisting or torsional stress due to such pressure cannot in-
crease the friction between the slide-block and the said crank-arm or concentric
lever.
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in Driving-gear for Bicycles and other Velocipedes.
I, ARTHUR THOMAS COLLIER, of Gonvena, St. Albans, in the County of Herts,
Engineer, do hereby declare the nature of this invention and in what manne:
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
―
My invention relates to driving-gear for velocipedes, of the kind or class
wherein compound cranks are employed so that a greater leverage will be
obtained during the downward or operative movement of the crank than during
the upward or return movement thereof.
And my said invention relates more particularly to driving-gear such as 1
have described in the Specification of former Letters l'atent granted to me and
dated 21st May 1896, No. 11105, in which the variation of the leverage is brought
about by means of eccentric levers each comprising a rotary strap movable about
á stationary disc fixed to the frame of the machine and eccentric to the driving-

page_text: shaft, which levers are coupled respectively to slide-blocks or heads movable to
and fro upon the crank-arms or concentric levers.
The chief object of my present invention is to so construct the said driving-
gear that the twisting or torsional stress to which the parts are subjected
by reason of the driving force or pressure applied to either pedal will be trans-
mitted to the corresponding stationary disc or eccentric and will therefore not
increase the friction between the crank-arm or concentric lever and the slide-
block or head.
For this purpose I make the upper and under surfaces of each crank-arm or
concentric fever curved in transverse section in such a manner that the curves
form part of a circle the centre of which coincides with the centre of the said
arm or lever and I provide the said slide-block or head with guide-rollers that
bear against the upper and under surfaces of the said crank-arm or concentric
lever, which rollers are made with peripheral grooves curved in transverse
section to correspond to the curved edges of the crank-arm and are preferably
mounted on ball-bearings constructed and arranged as hereinafter described;
and I so construct the parts that there is sufficient space between the sides of the
crank-arm or concentric lever and the walls of the slide-block to obviate any
liability to contact or friction between these parts. When the driving-gear is
thus constructed, no increase of friction can take place between the crank-arm
and the slide-block by reason of any twisting or torsional stress due to pressure
on the pedal, the bearing surfaces always being in the same operative relation to
each other. The twisting of the slide-block is, moreover, restricted by the con-
nection of the same to the eccentric strap and the fixing of the eccentric as
hereinafter described.
The ball-bearings for the said rollers comprise balls running in V-shaped or
other suitable grooves formed in the sides of the said rollers, and in corresponding
grooves formed in the inner sides of the walls of the slide-block, which is made
in two parts, being divided longitudinally, preferably in a central vertical plane.
The said grooves in the rollers and in the slide-block or head can be readily
formed by means of a cutter mounted in a rotary mandrel which is introduced
into a hole in the roller or in the wall of the slide-block or head as the case
may be.
I find it advantageous to make the slide-block or head from two solid
pieces of steel of one-half the thickness of the said slide-block, and to form in the
said pieces suitable recesses to receive the aforesaid rollers, and suitable slots to
permit the said crank-arm or concentric lever to pass through the said slide-
block; and to fit each half of the said slide-block with hardened discs having
formed therein the grooves for the balls and the hole to receive the said mandrels.
To effectually ensure rigidity of the stationary discs or eccentrics, I not only
attach the same rigidly to a clamp fixed on the frame of the machine, but I also
connect them together by means of a bridge-piece or stay so constructed as to be
clear of the chain-wheel when such is employed.
By these means undue twisting of the slide-block relatively to the crank-arm
or concentric lever is effectually prevented.
In the accompanying drawings.
Figure 1 is a side elevation of my improved driving-gear, a portion of the
slide-block being broken away.
Figure 2 is a plan or top view of the said driving-gear.
Figure is a side elevation, drawn to an enlarged scale showing one of the
halves or sides of the slide-block, and
Figure 4 is a transverse section through the crank-arm or concentric lever
and the slide-block, drawn to the same scale as Figure 3.
Each crank-arni or concentric lever a is made with its upper and under sur-
faces curved in transverse section, as shown more clearly at a', a in Figure 4,
so that the curves form parts of a circle struck from the centre of the said crank-
arma. The guide-rollers carried by the slide-block or head b are made with
peripheral grooves c¹ correspondingly curved in transverse section; and the longi-

page_text: tudinal slot 6 through the slide-block b is made of greater width than the crank-
arm a, so as to leave spaces between the sides of each crank-arm and the slide-
block thereon. By this arrangement, notwithstanding any slight twisting or
turning of the said slide-block about the centre of the said crank-arm in the
direction indicated by the arrow in Figure 4, by the force exerted upon the
pedal, the friction between the slide-block and crank-arm will not be increased,
and therefore the resistance to movement of the said slide-block along the crank-
arm will be approximately constant for any given relative position of these parts.
The slide-block shown is made from two solid pieces of steel of about one-half
the thickness of the said slide-block, and in which are formed suitable recesses g
to receive the rollers c, and suitable slots b¹ to permit the crank-arm or con-
centric lever a to move to and fro in the said slide-block without coming in
contact with the sides thereof. One or more liners h may, if desired, be fitted
between the two halves of the slide-block to keep them at such a distance apart
as to ensure the proper working of the ball-bearings d.
The ball-bearings for the rollers c comprise balls d running in V-shaped or
other suitable grooves e formed in the sides of the said rollers, and in correspond-
ing grooves e formed in steel discs m which are hardened and fixed in the inner
sides of the walls of the slide-block b, the said slide-block being made in two
halves or parts as above described. The said grooves e in the rollers and in the
discs m can be readily formed by means of a cutter mounted in a rotary mandrel
which is introduced into a hole f in the roller or in the disc m as the case may be.
The pedal-pin is fixed in a lug or eye 62 formed on the front end of the slide-
block b at or near the top thereof; or this lug may be formed on the top of the
slide-block as shown by dotted lines in Figure 3; and on the rear end of the said
slide-block bat or near the bottom thereof I form another lug or eye whereby
it is coupled to the eccentric strap k.
To effectually ensure rigidity of the stationary discs or eccentrics p, I not only
attach them rigidly to a clamp-bracket fixed on the frame of the machine, but
I also connect them together by means of a bridge-piece or stay r so constructed
as to be clear of the chain-wheel when such is employed.
It will be seen from the foregoing description that the crank-arms or con-
centric levers cannot be subjected to the twisting or torsional stress due to the
driving force or pressure exerted on the pedals, and that the twisting or torsional
stress due to such force cannot increase the friction between the slide blocks and
the said crank-arms or concentric levers.
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:
First. Driving-gear of the kind or class hereinbefore referred to, wherein the
upper and under surfaces of the crank-arm or concentric lever and the periphery
of each of the guide-rollers therefor have the form in transverse section of a
circular are the centre of which coincides with the centre of the said arm or
lever, suitable spaces being left between the said arm or lever and the sides of
the slide-block carrying the said rollers, for the purposes above specified.
Second. The improved driving-gear for velocipedes constructed, arranged and
operating substantially as herein before described with reference to the accom-
panying drawing and for the purposes specified.
Dated the 19th day of Amil 1800
ARTHUR T. COLLIER.
1. Young & Co.,
11 and 12, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.