Improvements in Mechanism for Transmitting Power at Varying Speeds.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Mechanism for Transmitting Power at Varying
Speeds.
I, MICHAEL HOLROYD SMITH, of 47, Victoria Street, Westminster, Consulting
Engineer, do hereby declare the nature of this invention to be as follows:-
The details of this invention though applicable to numerous uses, have been
specially designed for motor cars, where it is desirable to be able to proceed
at various speeds, also to reverse wlien required.
I am aware that belts running slack on different sizes of pulleys tightened by
means of "jockey pulleys" have been used that cone pulleys with shifting
belts and other like devices have been employed most of them requiring the
suppliment of clutches, frictional or otherwise for engaging & disengaging the
power, and bevel wheels or cross belts for reversing.
The objections to plain cone pulleys are well known the loss of power attend-
ing-friction clutches, and the shock & risk of breakage to positive clutches are
also well known.
When belts are employed it is also necessary to provide some device or facility
for tightening the same, in order to obtain the tension requisite for driving.
The object of this invention is to remedy the difficulties hitherto obtaining,
and to simplify the operation. To make a single belt perform the function of
transmitting power at various speeds and also act as the clutch.
For this purpose, on a continuation of the crank shaft, when an engine is
employed, or on the driving shaft, I place a cone or step pulley, also a friction
wheel, with grooved or other surface, and below or on one side thereof I place
another cone or step pulley so proportioned that the same length of belt may
be employed on the different.steps of the opposing pulleys, also a friction wheel
to engage with the friction wheel on the driving shaft.
The driven shaft runs in bearings held in a fender or cradle, one side of
which is pivotally supported by the framework carrying the driving shaft, and
the other side is suspended by a link, screw, lever or other convenient device,
so that it can be operated by the hand or foot of the attendant.
The steps of the pulleys are preferably separated from each other by a slope
or cone to facilitate the shifting of the belt.
When the cradle is in the neutral position the belt is slack, and no power is
transmitted, but as soon as the cradle is moved outwardly the belt is tightened
and power transmitted, and in the case of a motor car, a forward movement is
produced. When the cradle is drawn inwardly, the belt being slack, the two
friction wheels are brought together and the power transmitted in a reverse
lirection, and the car made to move backwards.
It will thus be readily seen that by the employment of a hand lever or screw
the cradle can lie held in a neutral position and no power transmitted, and
by turning the lever or screw in one direction forward movement can be

page_text: obtained, and by turning it in the opposite direction backward movement can
be obtained.
The lever or screw operating the cradle may be so connected with the brake
lever of the car, that as soon as the brake lever is moved the belt is slackened
before the brake is applied to the wheels of the car.
The shifting of the belt is preferably done when the belt is slack and the
slackness can be obtained either by turning the operating handle or by slightly
pressing the brake lever.
For varying the ratio of transmission the belt can be shifted from one step
of the cone or step pulley to the next, by any convenient means. It is how-
ever desirable that the movement from step to step should be positive, and for
this purpose I, preferably employ the following device.
On fixed bars or rods between the two step pulleys is placed a sliding carriage
having forks (preferably carrying rollers) embracing the belt to be moved, and
on this carriage is pivoted a rocking sleeve through which a connecting rod is
free to slide the other end of the connecting rod being preferably operated
by a crank. The "throw" of the crank pin being equal to the required shift of
the belt. On the fixed bar or rod supporting the sliding carriage a series of
notchies are formed likewise on the connecting rod sliding in the rocking sleeve;
and to the sliding carriage is attached a pawl or catch free, to engage with the
said notches, and held securely in position by a spring.
When the crank is turned in one direction the connecting rod lifts the said
pawl out of the notch in the fixed bar or rod, the notch in the connecting rod
engaging with the said catch, the continued movement of the crank draws the
sliding carriage forward and shifts the belt one step.
When the crank pin reaches, the dead centre, the connecting rod descending
allows the catch or detent to fall into the next notch on the fixed bar or rod
holding the carriage in position, and the notch in the connecting rod moves
away from the detent, and the connecting rod is free to slide through the rock-
ing sleeve during the return movement of the crank pin. If the crank is again
turned in the same direction the movement is repeated and the belt is shifted
another step forward. By reversing the movement of the crank the operation is
reversed and the belt is shifted in the reverse direction.
I also preferably employ an indicator on the handle that operates the crank
to show the position of the belt whether it be at fast, slow, or an intermediate
speed.
In transmitting the power from the driven shaft to the axle of the carriage
or other machinery to be operated; a belt or chain can be employed in. the.
usual way.
When the power is transmitted direct by means of shafting flexible connec-
tions are preferably employed to compensate for the movement of the shaft
held in the rocking cradle, and in the case of motor cars for the movement of
the axle of the car wheels.
Dated this Fourth dow of July 1800
COMPLETE SPECIFICATION.
Improvements in Mechanism for Transmitting Power at Varying
Speeds.
I, MICHAEL HOLROYD SMITH, of Albany Buildings, 47, Victoria Street, West-
minster, Consulting Engineer, do hereby declare the nature, of this invention

page_text: 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 this invention is to improve the means of transmitting power
from one shaft to another at varying ratios of speed, to facilitate the continua-
tion, or interruption of the transmittion, and to reverse the direction of the
driven shaft when desired.
The design has been worked out specially for use on motor-cars, but it is
applicable to other purposes.
In order that this invention may be more easily understood reference is made
to the accompanying drawings, in which like letters and figures refer to like
parts.
Fig. 1 (Sheet I) is a side elevation of part of the frame-work of a motor car
with this invention attached.
Fig. 2 (Sheet 1) is an end elevation of the same, partly in section.
Figs. 3, 4 and 5 (Sheet 2) show somewhat diagramatically the method of
shifting the belt.
A rigs. 1 and 2 is the first or driving shaft, in this case coupled direct to
the crank shaft of the engine.
Bis a step pulley placed thereon having sloping portions b, b, b, between
each step.
Cis a friction wheel the surface of which is preferably grooved' in an approved
manner.
1) is the driven shaft having upon it the step pulley E similar to B also a
friction wheel F grooved to correspond with C, and preferably of larger diameter.
The steps upon the pulleys B and E are preferably of such proportions that
the same length of belt may be employed on the different steps of the opposing
pulleys.
The driver shaft D runs in bearings, held in a fender or cradle & pivotally
supported one side H to the framework carrying the driving shaft A, the
other side I is. suspended by a link, screw, lever, or other convenient device so
árranged that it can be raised or lowered by the hand or foot.
When the fender G is in a mid-position, the belt K is slack, and the friction
wheels C and F are free from each other and no power is transmitted from
shaft A to shaft D. When the cradle is lowered or moved outwardly the belt
or chain is tightened, and power is transmitted, and in the case of the applica-
tion of this invention to a motor-car a forward movement is produced, the ratio
of speed being determined by which of the steps of the pulleys B and
helt may be on at the time.
the
When the cradle G is raised or drawn inwardly, the belt or chain is again
slackened and the friction wheels C and F are engaged and. a 'reverse movement
is obtained; and when this invention is applied to a motor car it runs backwards.
Many and various combinations of screws, wedges, cams, levers and the like
could be employed and I do not limit myself to the one shown, which consists
of a link L connecting the fender G to a joint at the end of the lever M.
Springs and may be interposed to compensate for the lack of flexibility in
a short strong belt or chain. The other end of the lever M is jointed to a nut m,
through which passes the screw N which is continued upwards through the
tubular support O, hand wheel P is secured to the top of the screw shaft N for
operating the same. The lever M is pivoted upon the pin R, secured to the
plunger S having upon its upper end the roller wheel s.
he free to rise if it were not restrained by the cam T at the base and forming
This plunger would
part of the brake lever V. The object of this arrangement is (assuming the
cradle G to be lowered & the belt or chain driving tight) that the first move-
ment of the brake lever shall be to relieve the cam T from engaging with the
rollers, thus perimitting the plunger S carrying the fulcrum R to rise and thus
relieve the pressure on the cradle G and slaken the belt or chain before the brake
is applied to the axle or wheels of the car: when pressure is removed from the

page_text: brake lever, a spring arranged in any convenient manner, will pull it and the
cam T into the position shown, thus restoring tension upon the belt K and
causing the car to move forward.
Shifting the belt is..preferably done when the belt is slack and the necessary
slackness can be obtained either by turning the operating handle P or by
slightly pressing the brake lever.
For varying the ratio of speed transmission the belt can be shifted from step
to step by the mechanism shown by the parts indicated in the Figures 1 to 5
on the drawings 1, 1. Figs. I and 2 (Sheet 1) are rocking guides embracing
the belt on both sides, and they are attached to sliders 6 moving. upon the
guide bars W. It is necessary that the movement from step to step should
be positive and the method of working. will be better understood by reference
to Figs. 3, 4, 5 (Sheet. 2) which are somewhat diagramatic (the rocking
guides 1, 1, Figs. 1 and 2, being omitted for the sake of simplicity.)
In Figs. 3, 4 and 5, W is a slide bar or tube fixed between the two step
pulleys, having notches 5, 50, 51, 5 in its upper surface to correspond with the
steps of the pulleys. 6 is a box or sleeve free to slide to and fro on the bar-W.
This box has a paul or detent 7, hinged at its joint 8 and free to fall into any
of the notches 5 that it may be opposite, by its own weight or assisted by a
spring, at the joint 8 is hinged a box or sleeve 9 through which is free to slide
a connecting rod 10 coupled to the crank pin 11, and having on its upper surface
notches 12, that also correspond with the steps in the pulley. Assume the
crank pin to be turning in the direction indicated by the arrow, Fig. 3, the
box 6 will be held in position because the detent 7 is in the notch 5¹ and the
connecting rod 10 will be free to slide through the box 9; but when the crank
pin approaches the dead centre X (see Fig. 4) the connecting rod 10 will have
so far entered the box 9 as to cause the notch 12 to engage with the outer
portion 14 (Fig. 5), of the detent 7; the crank pin 11 continuing its motion the
connecting rod 10 will raise the inner portion 13 of the detent 7 (Fig. 5) out
of the notch 5¹ and being thereby also restrained from sliding through box 9 (see
Fig. 4) will by means of pin or joint 8 also draw the box 6 along W; and as
the crank pin approaches the dead centre Z, the connecting rod 10 will lower,
allowing the inner portion 13 of the detent 7 to fall into the notch 50 on the
bar W retaining the box 6 in that position; and the connecting rod 10, con-
tinuing to lower its notch 121 will cease to be in contact with the outer portion 14
of the detent 7, and it will lie free again, to slide, through the box 9 and bring
notch 12 into contact with the detent, and so carry the box 6 forward another
step.
By reversing the direction of rotation of the crank pin, the process will be
reversed, and the slider or box 6 will be moved step by step in the contrary
direction. Suitable stops 21 and 22 could be placed at either end to prevent
the box 6 from travelling too far. 15, 15, Fig. 5 indicate forks for guiding
the belt; though rocking guides as indicated by 1, 1. Figs. 1 and 2 would
be preferably employed.
For security in shifting, a belt or chain upon step pulleys so near together as
shown, it is better to employ mechanism just described in duplicate, one on
either side, in which case one crank pin 11 would be set slightly in advance
of the other, so as to bring one end of the belt off to a lower step before
lifting the other end on to the next higher step.
The small crank shaft 16 can be operated by bevel wheels 17 (Figs. 1 & 2)
one of which could be keyed upon a tube 18 contained in the hollow pillar O
and having a crank handle 19 at the top. This crank handle could be made
to operate an indicator 20 which would be provided with pins 23, one for each
step of the pulley. The periphery of the indicator having figures marked
thereon at each revolution of the crank handle 19 the lug 24 would engage with
the uppermost pin, moving it forward a step and bringing another figure to the

page_text: top the operation being similar to that of the star wheel used to record the
travel of a bicycle.
In transmitting power from the driven shaft D to the axle of the carriage,
or other machinery; a belt or chain can be employed in the usual manner. When
it is desirable to transmit by shafting, flexible couplings would be employed
to compensate for the up and down movement of the shaft D with the cradle
or fender G.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be employed, I declare that what
1 claim is:-
1st. In transmitting power at varying speeds, the combination of step or conc
pulleys, belt and cradle substantially as and for the purpose described and
illustrated.
2. The combination of two pulleys (plain, step or cone) a belt or chain, with a
cradle or fender substantially as and for the purpose described and illustrated.
3. The combination of pulleys, belt and cradle with screw, lever or other
tightening device for applying or releasing the power substantially as and for
the purpose described and illustrated.
4. For transmitting power at varying speeds and in the same or reverse
direction as the prime mover, the combination of pulleys, belt, friction wheels,
and cradle substantially as and for the purpose described and illustrated.
5. The combination of screw, handle, lever, link and springs for operating the
cradle G substantially as and for the purpose described and illustrated in
Figs. 1 & 2.
6. The combination of a brake lever with a cam, operating on a plunger or
other equivalent device for releasing the tension on the driving belt, substantially
as and for the purpose described and illustrated.
7. The arrangement of parts substantially as described and shown in Figs. 3, 4
and 5 for shifting belts on step pulleys.
8. The combination with the parts shown in Figs. 3, 4 and 5 of the wheels,
hollow shaft, handle and recorder or any or all of them as shown in Figs. 1
and 2, for shifting the belt on step pulleys.
9. For transmitting power at varying speeds and, in different directions of
rotation and for shifting the belt, the general arrangement of parts herein
described and illustrated.
Dated this 4th day of Anvil 1900.