Improvements in Gear for Propelling Cycles and like Vehicles.
Year: 1897

page_text: Date of Application, 13th Feb., 1897
Complete Specification Left, 13th Dec., 1897-Accepted, 12th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in Gear for Propelling Cycles and like Vehicles.
JAMES MURRIE, 12, Houldsworth Street, Glasgow, North Britain, Engineer, do
hereby declare the nature of this invention to be as follows:-
My said invention relates to certain improvements in the apparatus for transferr-
ing the energy imparted to the pedal cranks of cycles to the axis of their driving
wheel or wheels by means of endless cords or bands in place of the endless chain
at present in general use.
In carrying my said improvements into practice I fit rigidly on to the pedal
crank axis at each extremity a disc or pulley. The periphery of each pulley is
recessed with one or more grooves, each groove having its sides slightly tapered
towards the base or root. Said pulleys have pedal crank pins directly secured to
their outer sides to permit their acting as crank discs.
The driving wheel axis is fitted with grooved pulleys corresponding to and in
the same plane as the aforesaid crank discs.
The aforesaid grooved pulleys are in gear with each other by means of endless
bands of cord, which have cores of metal, preferably of pianoforte steel wire. Said
core consisting of one or more strands lying parallel to each other, and, which
withstand the tensile strains while the outer covering prevents slip.'
Instead of window cord with its metal core any kind of band may be employed
such as steel or other metal wire, rubber coated wire, plain window card, leather
bands, animal intestinal matter known as 'gut' or analogous material.
The feature in the arrangement consists in having more than one endless band
and in making the pulley grooves with a slight taper so that the cord will not
bear against the base or root of the groove but be jammed betwixt the tapered sides
in such a way that with an increased strain the "bite' is automatically increased
and slip rendered impossible.
Guides are fitted to the cycle frames to direct each band to its respective groove.
The pulleys are preferably made of metal but these may consist of metal and
wood combined. The cores or bosses being of metal and the peripherys of wood.
Doted this 12th dor of Fehmuary 1897

page_text: 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 replace the metal link chain at present in
general use on bycles for transmitting the energy from the pedal crank axis to the
axis of the cycle driving wheel, by means of an endless band or bands of fibrous
or metallic material.
This I effect by replacing the chain wheels keyed to, or attached to the afore-
said axles, with pulleys which are provided with recessed grooves on their outer
surfaces; the inner sides of said grooves or recesses being slightly tapered inwards
towards their base in such a way that bands of a circular section embrace one side
of the pulleys by wholly or partly entering the groove or recess without bearing
against the base or root of the groove. The endless band thus transferring the
motion from the pedal axle to the driving wheel axle of the cycle at a surface
velocity equal to the velocity of the bands.
When of advantage the bycle is fitted on both sides with band pulleys, there
being one or more grooves on each pulley, and the crank pedal pin is fitted directly
to the driving pulleys on their outer sides.
The endless bands when of organic fibrous materials have one or more metal
wires inside and the whole band is saturated with glycerine, rubber or gutta percha
solution to render these waterproof.
I do not confine myself to use fibrous materials such as hemp, and, may use bands
made of leather, gut, metal wire single or coated with rubber, or bands constructed
of analogous materials.
Each pulley is provided with a rigid guard to prevent the bands coming off and
with guides preferably of the small guide pulley type to guide each band on to its
respective groove.
In order that my invention be understood I will describe the apparatus by refer-
ence to the accompanying sheet of drawings:-
Fig. 1. Illustrates the application of the endless bands to transmitting the motion
from the crank axis to the driving wheel axis of a cycle.
A. Represents the driving pulley attached to the crank axle; B, the correspond-
ing pulley on the driving wheel axis; C, the endless bands; D the foot or pedal
pin.
Fig. 2. Represents in plan the the twin set of driving gear on the opposite side
of the machine. The letters A¹, B', C¹; D' representing the corresponding parts
described under Fig. 1.
.
Fig. 3. Illustrates one of the pulleys referred to. E represents the pulley, F the
recessed grooves; G section of a band consisting of metal or fibrous material; H,
the axle to which the pulley is keyed or attached, and which forms part of the
pedal axis or the axis of the driving wheel.
Fig. 4. Illustrates in section the construction of a band of fibrous material pro-
vided with one or more metal wires. I. represents the pianoforte or other wire;
K the fibrous material, preferably hemp.
Fig. 5. Illustrates the application of guards and guides. L, represents the metal
guard attached to the frame of machine by means of one or more pins or other con-
venient manner as seen dotted lines Figure 1. M, the pulley guides for guiding
the band on to its groove, and which form part of the guide or guard L.
The modus operandi of the arrangement consists in transmitting the energy
from the crank axis to the driving wheel axis intact, or with little or no loss
through friction or slip. The grooves just taking in the circular sectioned band
without the band touching the base or root of the groove, permits the sides of the
groove automatically biting into or embracing the band, and, the greater the
endency to slip through a severe strain, the firmer the band is held. The advan-
tage in having more bands than one is that the strain is reduced per endless band
and with pulleys on both sides of the machine, the strains on the machine journals
are more evenly distributed.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare what I
claim is:-
(1) In velocepedes of the two wheeled safety type, the transmission of energy
from the crank axis to the cycle driving wheel by means of double sets of grooved
pulleys and endless bands, (one set on each side of the machine) substantially as
herein before described and illustrated on Figs. 1 and 2.
2 In safety bycle driving gear, the use of multi-grooved pulleys operated by end-
less bands substantially as herein before described and illustrated on Figs. 1, 2 & 3.
3 The combined pedal crank pin and endless band pulley substantially as here-
inbefore described and illustrated on Fig. 1 and 2.
4 The application of endless bands of fibrous material with internal metal wires
to propel cycles by grooved pulleys substantially as hereinbefore described and
illustrated on Figs. 1, 2, 3 & 4.
5 In combination with the driving gear claimed in the preceding claim, the
endless band guard and guide fitted to the frame substantially as herein before
described and illustrated on Fig. 5.
JAMES MURRIE,
Bottomley & Liddle,
154, St. Vincent Street, Glasgow, Applicant's Patent Agents.