An Improvement in the Driving Gear of Chainless Cycles and such Vehicles.
Year: 1897

page_text: Date of Application,' 18th March, 1897.
Complete Specification Left, 20th Dec., 1897-Accepted, 5th Feb.,
1898.
PROVISIONAL SPECIFICATION.
An Improvement in the Driving Gear of Chainless Cycles and such
Vehicles.
1, OLIVER GOLDSMITH IEVERS, of Akola Bevar, India, Captain in H.M.'s Indian
Staff Corps, do hereby declare the nature of this invention to be as follows:-
My invention relates to chainless cycles and has for its object to so construct the
gear that it will be simple and work with reduced friction or increase the driving
power of same.
To accomplish this object I employ two cog wheels and a screw threaded driving
rod. One cog wheel, to the axle of which are fixed the cranks or pedals, is moveably
fastened to the bottom bracket of the cycle and gears with an endless screw at the
front end of the driving rod enclosed in the back stay tube of the cycle. This
driving rod extends through the back stay tube to the rear end of the same, where it
is also provided with an endless screw fitted to gear with the second_cog wheel
fixed to the axle of the rear or driving wheel.
On moving the pedal on the first cog wheel the driving rod is turned, whereby it
is imparted to the second cog wheel on the axle of the driving wheel.
The ends of the said driving rod are held and revolve in bearings screwed into or
fastened to the ends of the back stay tube. To this tube are suitably fixed two
boxes, one enclosing the cog wheel on the crank axle and made in two halves, and
The back stay
the other enclosing the cog wheel on the rear or driving wheel axle.
tube and boxes form a single encasement which excludes all dust and dirt and
obviates any danger which might otherwise be caused by the gear. For lubricating
purposes small holes are provided above the gear in the back stay tube.
The thread of one or both of the endless screws on the driving rod may be single,
double or treble, and the diameter and number of teeth of the cog wheels may be
equal or vary in size. By altering the pitch of the endless screw threads on the
driving rod, the diameter of the cog wheels and the number of teeth in same, and
by a combination of screws having different numbers of threads an increased power
and a gearing of considerable range is obtainable.
It will readily be seen that the said driving rod is simpler in construction and
much cheaper than a chain, that it does not require a special gear case, and will work
without a rattling noise and with reduced friction.
Dated this 18th day of March 1897.
PHILLIPS & LEIGH,
Agents for the Applicant.

page_text: An Improvement in the Driving Gear of Chainless Cycles and such
Vehicles.
I, OLIVER GOLDSMITH LEVERS, of Akola, Bevar, in the Indian Empire, Captain in
H.M. Indian Staff Corps, 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 an improvement in the driving gear of chainless cycles and
such vehicles, its object being to reduce the number of parts of such gear, that the
friction will thereby be lessened and consequently greater useful effect obtained from
the initial motive power exerted on the cranks by the rider.
To accomplish the above object I employ, in place of the ordinary bevel gearing,
a worm gear, that is to say, a rod having a worm or portion of an endless screw
thread at each end thereof hereinafter called the driving-rod is placed tangential to
and gears with two worm wheels mounted one fast on the crank axle and the other
fast on the axle of the driving wheel.
The driving rod is preferably supported within the bottom stay-tube of the cycle
frame, an enlargement or box being provided at each end of the said stay tube to
receive and house the somewhat larger screw-threaded portions of the said rod. The
said enlargements or boxes are closed at their ends by a plug or screw stopper in
which the bearing for the end of the driving-rod may be made.
The thread of one or both of the endless screws on the driving-rod may be single,
double, or treble, and the diameter and number of the teeth of the engaging worm
wheels may be equal or may vary in size. By altering the pitch of the endless screw
threads on the driving-rod, the diameter of the worm wheels and the number of
teeth in same, and by combination of screws having different numbers of threads an
increased power and a gearing of considerable range is obtainable.
The two cogged or spirally toothed wheels which engage in the worms on the
driving rod are preferably enclosed in a case or cover connected to the bottom of the
enlarged ends or boxes on the ends of the bottom stay tube before explained, to
exclude dust and dirt from the mechanism within and to obviate any danger or
accident that might arise from the gear catching in the clothes or which might
otherwise be caused by an exposed gear, and the said case or cover may, for convenience
of fitting and inspection of the gear, be made in two or more parts hinged or bolted
together.
To facilitate the withdrawal of the driving-rod from the stay tube, the worms on
the ends of it may be made quite separate therefrom and only fixed thereon in
position by means of a key or spline, so that the worm may be drawn out previously
to the rod which will then pass through the narrowest portion of the tube easily.
Spare driving rods made to different proportions of gear could be supplied for
either multiplying or reducing the speed as desired.
In order that my invention may be fully understood I will now proceed to describe
it with reference to the accompanying sheet of drawings in which
Figure 1 represents in side élevation a bicycle fitted with my improved driving
gear, shown in section.
Figure 2 represents my improved driving gear in elevation detached from the
cycle, and
Figure 3 is a sectional elevation on the line 2-2 of Figure 1, looking towards the
pedals.
The bottom stay tube a of the cycle frame contains the driving-rod b which is
supported centrally within it in bearings c, c¹ in the screw stoppers d, d¹. The ends

page_text: of the tube a are enlarged or provided with boxes g, h to permit of the entrance and
reception of the two worms e and f. A worm-wheel e¹ is mounted fast on the crank
axlej so that its teeth will engage in the thread or worm e on the front end of the
driving-rod, and another worm wheel f¹ is mounted fast on the axle of the driving
wheel m, and engages in the thread or worm f on the rear end of the driving-rod b.
The worin-wheels e¹ and f¹ are encased by the boxes n and n¹ which, as before stated
may be secured to the enlarged ends or boxes g, h in any suitable manner, and are
preferably made in two halves hinged or screwed together; and they may have
transparent sides if desirable.
The action of the gear is as follows:-On rotating the cranks, rotary motion
imparted to the worm-wheel e¹ which motion in turn is communicated to the driving-
rod 6 through the worm e. The motion is of course transmitted to the worm-wheel f¹
fast on the driving axle which rotates the driving wheel m and thus the cycle is
propelled.
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. Driving gear for a cycle or such like vehicles consisting of a driving-rod having
an endless screw thread or worm at each end thereof and rotatably mounted within
the bottom stay tube of the frame, a worm-wheel fast on the crank axle engaging in
the thread on the front end and another worm-wheel fast on the axle of the driving
wheel engaging in the thread on the rear end of the said driving-rod and casings to
enclose the said wheels and screw threads substantially in the manner herein described
and set forth.
2. Worm-wheel and tangent screw driving gear for cycles and such like vehicles.
Dated this 20th day of December 1807
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.