Improvements in Belt Driving Gear.
Year: 1894

page_text: Date of Application, 16th Jan., 1894
Complete Specification Left, 16th Oct., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Belt Driving Gear.
I, CHRISTIAN HAMILTON GRAY, of The Indiarubber, Gutta-percha and
Telegraph Works Company Limited, of Silvertown, Essex, Indiarubber Mann-
facturer, do hereby declare the nature of this invention to be as follows:-
This invention relates to driving gear which may be used in various ways and
upon various mechanisms, but it is particularly suitable for the driving gear of
cycles and I will describe it as so applied.
The nearest parallel to the present gear would be that of the ordinary chain-
driving mechanism, but in place of the chain I have a belt running preferably on
edge between two pairs of discs which may be arranged for example in the
following manner. The crank axle carries a disc preferably provided with a flange
or other circular projection or a series of projections upon its inner or working face
and against this fits another disc so that a peripheral groove adapted to receive the
belt is provided. The first disc is driven by the crank axle or crank; the second
by frictional contact with the belt which is nipped between the two discs. This
nipping is effected by placing the discs in planes very slightly off the parallel so
that at the point where the belt enters the space between the two discs it is not
gripped at all, and casily enters, but as it proceeds further round the discs it is
firmly gripped, while lastly, at the point where it leaves the discs it is again not
gripped. A similar arrangement is adopted at the other end only in that case both
discs are positively driven by the belt itself. In either case both discs may be
positively driven if desired; this in the case of the crank axle being easily
accomplished by lugs or equivalent upon the driving disc engaging with slots or
equivalent upon the other disc. Ball bearings may be used where required.
Any suitable belt may be employed for instance an india-rubber belt with canvas
or other non-stretchable material in it, or a leather belt, a cable or the like.
The nipping surfaces of the discs may be corrugated, roughened or provided with
recesses adapted to receive projections upon the belt so as to take a positive hold
on the belt if required.
Dated this 16th day of January 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Belt Driving Gear.
I, CHRISTIAN HAMILTON GRAY, of The Indiarubber, Gutta-percha and
Telegraph Works Company, Limited, of Silvertown, Essex, Indiarubber Manu-
facturer, 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 which may be used in various ways and
upon various mechanisms, but it is particularly suitable for the driving gear of
cycles and I will describe it as so applied.
The nearest parallel to the present gear would be that of the ordinary chain-
driving mechanism, but in place of the chain I have a belt running preferably on
edge between two pairs of discs which may be arranged for example in the

page_text: following manner. The crank axle carries a disc preferably provided with a flange
or other circular projection or a series of projections upon its inner or working face
and against this fits another disc so that a peripheral groove adapted to receive the
belt is provided. The first disc is driven by the crank axle or crank; the second
by frictional contact with the belt which is nipped between the two discs. This
nipping is effected by placing the discs in planes very slightly off the parallel so
that at the point where the belt enters the space between the two discs it is not
gripped at all, and easily enters, but as it proceeds further round the discs it is
firmly gripped, while lastly, at the point where it leaves the discs it is again not
gripped. A similar arrangement is adopted at the other end only in that case both
discs are positively driven by the belt itself. In either case both discs may be
positively driven if desired; this in the case of the crank axle being easily
accomplished by lugs or equivalent upon the driving disc engaging with slots or
equivalent upon the other disc. Ball bearings may be used where required.
Any suitable belt may be employed for instance an india-rubber belt with canvas
or other non-stretchable material in it, or a leather belt, a cable or the like.
The nipping surfaces of the discs may be corrugated, roughened or provided
with recesses adapted to receive projections upon the belt so as to take a positive
hold on the belt if required.
The invention will be best understood by reference to the accompanying drawings
which represent it as applied to a rear-driving cycle of which latter, only the
portions necessary to illustrate the invention are shown.
Figures 1 and 2 are longitudinal sections showing the application to the crank
axle and road-wheel respectively, and
Figures 3 and 4 are elevations of Figures 1 and 2 respectively.
Like letters indicate like parts throughout the drawings.
A is the crank-axle or driving shaft rotated by means of cranks A' and supported
in ball bearings B in the crank-axle-bearing bracket C in the usual manuer.
D is a disc or equivalent rigidly secured, as by a key A3, on the axle A truly
perpendicular thereto, and having conveniently an annular lip D' on which the
driving belt E is supported or runs, and F is another disc or equivalent mounted so
as to be slightly out of parallel with the disc D and not quite perpendicular to the
axle A. A convenient way of obtaining this result is to fit a bushing G into the
end of the bearing bracket C, adjacent to the discs D and F at a slight incline,
that is to say, so that its axis will be at an angle to the axis of the axle A as
indicated in Figure 1 where the dotted lines a and y represent respectively the
axis of the axle A and of the bushing G. On the outside of the bushing G I form
a race G' for receiving a ring of balls H and a screw-thread G for the reception
of the internally screwed collar I also provided with a race 1' for receiving a ring
of balls Hand of a lock-nut I'.
The disc is formed with races for receiving the balls H H and the collar 1
constitutes the means by which this bearing may be tightened or slackened.
It will be readily understood that by the foregoing means the peripheries of the
discs D and F will be nearer together at one part say the top of Figures 1 and 3
than at other parts, say the bottom of Figures 1 and 3.
In the arrangement shown in Figures 2 and 4 J represents the hub of the driving
road wheel of a bicycle which is mounted on its non-rotating spindle K through
the ball-bearings L and L' which are adjustable by means of the nut M in the
usual manner. The race K' for the balls L is formed on the enlargement or fixed
collar K2 of the spindle K and the race M' for the balls L' is formed on the nut M.
On the annular extension or collar J' of the hub J I screw as shown, or otherwise
secure the disc N which, like the disc D before described, and for a similar purpose,
is provided with an annular lip N'; this disc N is co-axial with the spindle K and
lies in a plane perpendicular to the axis thereof.
Outside the collar K³, as shown in Figure 2, the part K³, of the spindle is at a
slight angle to the other part as indicated by the dotted lines the letter k
representing the axis of the straight portion K of the spindle and k³ that of the

page_text: deflected portion K³. The spindle at K is externally screw-threaded for receiving
the ball-race-collars O O' the former of which is adapted to abut against the
inclined face K' of the collar K' and supplies the necessary surface or race O' for
the balls P to roll upon, while the latter supplies the necessary surface or race O
for the balls P. The balls P P furnish the bearing for the disc Q which is
provided with two ball-races Q'Q' the former for the balls P and the latter for the
balls P¹ these two races, like the corresponding ones of the disc F before-described,.
being separated, by an inwardly-projecting flange or lip Q³.
The spindle K K' may be adjustably supported in the fork R of the framework
in the usual mauner and the last-described bearing may be tightened or loosened
by screwing the collar O¹ in the proper direction upon the spindle K³, the collar
being afterwards secured in any such adjusted position by tightening up the nut S.
against the fork R as will be well understood.
By the foregoing means annular grooves are provided, which as shown in
Figures 3 and 4 respectively. are narrower at one part T or U than at the
diametrically opposite parts T' or U, the grooves graduating in width between
these extremes.
The belt E passes from the discs D F to the discs Q N and is gripped between
them at the part where the grooves are narrowest.
In operation these devices firmly grip the belt E at the narrowest part of the
grooves while leaving it free at the other or wider parts.
In Figures 3 and 4 I have shown the discs with their belt-engaging faces
corrugated; they may be formed either in this way, or plain, or with projections
for engaging with recesses in the belt, or with recesses for receiving projections
provided on the belt or otherwise so as to afford the necessary grip" on
the belt.
If desired both of the discs D F or QN may be positively driven instead of
only one as previously described, a result easily accomplished by one or more
lugs formed on oue disc engaging with one or more recesses in the companion
disc.
The belt E may be formed of leather or other non-stretchable material though
I find rubber with canvas incorporated in it gives very satisfactory results.
It is to be observed that although both of the discs DF or QN rotate
simultaneously together, the positions of the parts at which the belt is gripped and
released by them never vary owing to the inclined bearing on which the disc For Q
revolve being itself non-rotating; this moreover renders the angle of inclination of
each pair of discs constant.
In the word "disc" (DF &c.) in this Specification and claims I include other
forms of inclined faces, such as spoked wheels, rings &c.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is ;-
1. "Belt-driving" by means of two discs one inclined to the other substantially
as described.
2. In belt driving gear the employment of two discs rotating in planes not quite
parallel substantially as and for the purpose described.
3. In belt driving gear the employment of two discs rotating in planes not quite
parallel so as to form a peripheral groove narrower where it grips the belt than
elsewhere substantially as described.
4. In belt driving gear the combination with a belt or equivalent E and a
positively-rotated disc such as D or Q of a second disc such as For N rotating in
a plane inclined to that in which the first disc rotates substantially as described and
illustrated in the accompanying drawings.
5. The combination and arrangement of parts constituting the complete belt
transmitting gear substantially as described and illustrated in Figure 1 of the
accompanying drawings.

page_text: 6. The combination and arrangement of parts constituting the complete belt-
receiving gear substantially as described and illustrated in Figure 2 of the
accompanying drawings.
Dated this 12th day of October 1894.
CHRISTIAN HAMILTON GRAY.
W. P. Thompson & Boult,
Agents for the Applicant.