Improvements in Change-speed and Reversing-gear for Autocars.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Change-speed and Reversing-gear for Autocars.
I, WILLIAM THEODORE CARR, of 26, Lismore Terrace, Carlisle, in the County
of Cumberland, Manufacturer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to change-speed-mechanism for autocars and mechanic-
ally-propelled vehicles generally, and consists in an improved mode of construc-
tion whereby the employment of silent-running chain wheels, instead of
spur-gearing, is rendered permissible.
In change-speed-gear constructed and arranged according to my improved
method, a shaft, driven by a chain-wheel direct from the motor, has secured
upon it three wheels which gear, by means of silent-running chains, with three
wheels mounted freely upon a parallel shaft. The diameters of the several pairs
of wheels may be proportioned in any desired ratio to afford the particular speeds
required. The portion of the secondary shaft within the centres of the wheels
is of a larger diameter than that outside, and is grooved longitudinally. In
the grooves are fitted keys arranged to slide freely from end to end, these keys
carrying snugs which project beyond the normal surface of the shaft, the re-
maining portions of the keys being uniform therewith. In the inner surfaces
of the bosses of the wheels upon the secondary shaft are cut longitudinal grooves
adapted for the reception of the snugs. In the centres of the two outer wheels
are formed recesses, and a sliding collar connects the outer ends of the two
keys, the collar sliding with them along the shaft. This collar may be of any
form to be readily actuated from the driving-seat of the vehicle. Assuming
the centre wheel of the three wheels upon the secondary shaft to be driven
from the centre wheel of the three upon the primary shaft, motion is transmitted
to the secondary shaft and the car propelled at one speed. When, however,
the sliding collar is pushed along, so that the snugs are withdrawn from the
grooves and are free to rotate within annular recesses in the bosses of the
wheels, the latter are free to revolve without propelling the car, and, conversely,
the car is at liberty to run backwards or forwards without imparting motion
to any part of the chain driving gear. If the snugs be moved still further so
as to engage with the grooves in one or the other of the outer wheels of the
series, the secondary shaft will be rotated at a different speed, according to the
ratio of the wheels upon the primary and secondary shafts respectively.
For reversing, a pinion is mounted upon the primary shaft and arranged to
slide thereon, the connection between the pinion and the shaft being by means
of a feather working in a feather-way. When it is desired to reverse the
direction of the power transmission, the pinion is moved laterally so as to mesh
with a spur-wheel upon the secondary shaft.
10
.
1000

page_text: Improvements in Change-speed and Reversing-gear for Autocars.
I, WILLIAM THEODORE CARR, of 26, Lismore Terrace, Carlisle, in the County
of Cumberland, Manufacturer, 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 change-speed mechanism for autocars and mechanic-
ally propelled vehicles generally, and consists in an improved mode of construc-
tion whereby the employment of silent-running chain-wheels, instead of
spur-gearing, is rendered permissible.
In the accompanying drawings, Fig. 1 illustrates change-speed and reversing
mechanism constructed and arranged according to my invention. Fig. 2 is
a transverse section, on the line - in Fig. 1, of the secondary shaft, showing,
in elevation, the hardened centre of the wheel pertaining to the high-speed
gear. Figs. 3 and 4 are respectively longitudinal sections on the lines y-Y
and zz in Fig. 2. Figs. 5, 6 and 7 are respectively a side elevation, a plan
and an end-view of one of the keys and snugs employed in locking one or another
of the wheels of the change-speed-gear with the secondary shaft.
In change-speed-gear constructed and arranged according to my improved
method, a shaft a, driven by a chain-wheel b direct from the motor, has secured
upon it three wheels ce¹ which gear, by means of chains, with three
wheels ddd mounted freely upon a parallel shaft e, and maintained in position
thereon by means of the collars e eo. The diameter of the several pairs of wheels
may be proportioned in any desired ratio to afford the particular speeds required,
and all the said wheels may be shrouded. The portion e¹ of the secondary
shaft e within the wheels is of larger diameter than that beyond them, and is
grooved longitudinally. In the grooves are fitted keys ff arranged to slide freely
from end to end, these keys carrying snugs f'f' which project beyond the normal
surface of the enlarged portion e¹ of the shaft; the remaining portions of the
keys being flush therewith. In the inner surfaces of the bosses of the
wheels d dd, upon the secondary shaft e, are cut longitudinal grooves d* d¹³ d²*
adapted for the reception of the snugs f1f1; and in the centres of the two cuter
wheels are formed recesses 20 A collar connects the ends of the two
keys ff, the collar sliding with them along the shaft e. This collar may be
of any form adapted for ready actuation from the driving seat of the vehicle.
Assuming the centre wheel of the three wheels upon the secondary shaft e to
be driven from the centre wheel of the three upon the primary shatt a, motion
is transmitted to the secondary shaft c, and the car is propelled at one speed.
When, however, the sliding collar f is moved longitudinally, so that the
snugs ff are withdrawn from the grooves d in the boss of the wheel d
and are free to rotate within one or the other of the annular recesses do, do,
in the bosses of the wheels d or , the wheels d' are free to revolve upon
the shaft e without propelling the car; and, conversely, the car is at liberty
to run backwards or forwards without imparting motion to any part of the chain
driving gear. If the snugs flfl be moved still further, so as to engage with
the grooves d or 2 in one or the other of the outer wheels d or d of the series,
the secondary shaft e will be rotated at a different speed, according to the ratio
of the wheels upon the shafts a and e for the time being operative.
For reversing, a pinion g is mounted upon the primary shaft a so as to slide
thereon; the connection between the pinion g and the shaft being effected by
means of a feather a working in a feather-way. When it is desired to reverse
the direction of the power transmission, the pinion is moved laterally so as to

page_text: mesh with a spur-wheel h upon the secondary shaft e. i is a chain-wheel for
transmitting the motion from the shaft e to the balance-gear of the vehicle. k is
a drum for the brake-band.
It will be perceived that in a construction of the character described, the
spur-gearing is only brought into operation when reversing, which is seldom
necessary in vehicles of the particular type to which my invention is principally
applicable. It will also be apparent that a positive transmission of power is
secured which is not the case where leather driving belts or similar appliances,
which depend for their gripping effect upon frictional contact, are employed.
A further advantage secured by my invention is that no waste of power occurs
by reason of the running of the chains when they are not actually performing
the function of propelling the car. The chains, which are practically noiseless,
may be run slack, so that no noticeable friction occurs between the wheel centres
and the shafts whereon they rotate.
The bosses or centres of the wheels dd 2 are preferably of hardened steel,
the rims for carrying the chains being formed separately and attached by any
suitable means.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I claim: -
1. The improved change-speed mechanism for mechanically propelled vehicles,
arranged substantially as herein described, and comprising a shaft wheron are
secured suitably proportioned chain-wheels, which, through the intervention
of chains, gear with suitably proportioned chain-wheels freely mounted upon a
parallel shaft; the connection between each of the last mentioned chain-wheels and
shaft being effected by means of a sliding key which carries a projection adapted
to enter a key-way formed in the boss of each of the said wheels; the wheel
for the time being so engaged operating the secondary shaft, whilst the other
wheels are disengaged therefrom and are free to revolve at different speeds.
2. The combination, with change-speed mechanism of the kind referred to
in the preceding claiming clause, of mechanism for effecting reversal in the
direction of rotation, arranged and operating substantially as herein described.
མ་
For the Applicant,
G. G. M. HARDINGHAM,
Chartered Patent Agent.
Clun House, Surrey Street, London, W.C..