Improvements in Friction Gearing for Coupling Shafts.
Year: 1896

page_text: Date of Application, 29th Aug. 1896-Accepted, 8th May, 1897
COMPLETE SPECIFICATION.
Improvements in Friction Gearing for Coupling Shafts.
I, FRANÇOIS SINGRE, of 42 Boulevard Bonne-Nouvelle Paris, in the Republic
of France, Engineer, 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 a new mechanism for actuating one or more parallel
shafts by a third driving shaft situated in the same plane, and in which the
movement is transmitted by the friction of a roller upon a pulley, and is
characterized by the combination of the following devices:
(1) A device for obviating the pressure upon the shafts;
(2) A dovice for progressive coupling, obviating the sliding upon the contact
surfaces of the friction wheels;
(3) A device for uncoupling with a stop brake.
This mechanism for the transmission of motion is applicable to any apparatus
and machines, such as auto-motor vehicles, boats, windlasses and the like, in which
not only the communication of the motive power with the parts to be moved must
be frequently established and interrupted, but in which the motion of those parts
must be effected progressively without shocks or jerks and particularly without
injurious sliding upon the contact surfaces of the friction whoals, whilst the
stoppage of these parts must also be effected as rapidly as possible.
In order that the nature of my invention may be proporly understood I have
represented it in the accompanying drawing, in which
Figure 1 represents a vertical section in a plane passing through the axes of
rotation of the pulleys of the system.
Figure 2 is a front view of the mechanism.
Figure 3 represents a transverse section on the line y- of Figure 1.
This mechanism is substantially constituted by the combination of the following
parts
(1) The roller G fixed to the shaft g of the motor is adapted to contact at o
and p with two pulleys A and B of special construction, situated in the plane of
rotation of the roller G and pressed upon the latter by an elastic belt C which
encloses the three pulleys.
A second elastic belt F is placed upon the prolongations of the naves of the
pulleys A and B, and has for its object to diminish the reactions in the bearings of
the shafts a and b during the movement, the belt F also contributing to the
pressure exerted by the pulleys.
(2) The rims of the wheels A and B are covered with a metallic tyre m which
is loose upon these rims, that is to say adapted to turn freely. This movable tyre
is placed either directly upon the rim or with the interposition of an isolating
material I, such as wood, leather or the like, suitably lubricated and designed to
mitigate shocks and obviate the noise. The elastic belt C tends to cause the
approach of these two tyres m upon which it is mounted, whilst the elastio belt F
tends to cause the approach of the rims of the wheels A and B.
(3) A device for regulating the pressure exerted with the aid of tho before-
mentioned clastic belts, and constituted by a lever L freely articulated upon the
haft or upon its support and connected to the bearings of the shafts a and b by
ods D D' which are themselves articulated upon the said lever above and below
ts centre of oscillation.
This lever enables the shafts a and b to be brought together or to be separated.
ts movement is limited on the one hand when I cause the pulleys A and B to be

page_text: pressed upon the surfaces o and p of the roller G, and on the other hand when I
block the rims of the wheels A and. B upon the brake shoes S S placed in the
interior of the rims in the fixed supports.
The operation of apparatus is as follows:-In the position of the parts shown in
the drawing, and which for example relate to an application to lifting or loading
and unloading apparatus, the lever L is under the action of a counterweight P
which keeps the apparatus out of engagement, that is to say the wheels A and B
blocked by the brake shoes S S₁ upon the contacts &s. In this position the
whole apparatus to which my system is adapted is therefore kept at rest. The
roller G turns alone under the action of the motor.
For effecting the coupling of the shafts a and b it will be sufficient to raise the
counterweight P, either directly by hand or in any suitable manner, in order to
cause theso shafts to approach; the upward movement being continued the
coupling takes place by the following series of phases:
(a) The tyres m come in contact with the roller G; then the pressures resulting
from the elastic belt C at the points ii are suppressed and transferred to the roller
to the two points o and p, and the tyres becoming free are moved by the roller.
As the mass of these tyres is small this movement takes place immediately
without any appreciable sliding upon the contact surfaces.
(b) The rims of the wheels A and B, under the action of the second elastic
belt Faud by the device for regulating the pressure, will press in the interior of
the tyres m m at the points. They are then moved progressively by the tyres
in motion, at the will of the operator; the sliding which is caused at first and
during the period of coupling takes place upon the whole interior surface of the
rim and tyre suitably lubricated and no longer upon the peripheries o and p.
It should be observed that the pressure necessary for this interior movement of
the rims is added to that of the elastic belt C, and gives an excess of pressure
upon the peripheries o aud p, preventing any sliding upon these latter points not
only during the coupling but also during the motion.
The lever L left to itself under the action of the weight P causes the rapid and
automatic stoppage of the parts which are set in motion by the shafts a and b.
This lever and also the corresponding mechanism serve for effecting the coupling,
the uncoupling and the stoppage.
The mechanism shown in the drawing by way of example as a speed reducer
may also be used as a speed increasing device. Moreover, the second elastic
belt F may in certain cases be dispensed with.
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 :-
First. A mechanism for the transmission of motion by friction, characterized
by the combination of a central roller which receives the movement from the motor
in order to transmit it to two pulleys caused at will to move away from or approach
the said roller by means of a lever and eccentric rods, these two pulleys, surrounded
by an elastic belt, being covered at their periphery each by a tyre free to effect
the progressive coupling; and the apparatus being completed by fixed brake shoes
upon which are applied the interior faces of the rims at the time of the uncoupling
to effect the rapid stoppage.
Second. In a friction wheel the interposition, between the movable tyre and the
rim of the pulleys, of a packing composed of leather to obviate the shocks suppress
the vibrations and render the movement silent.
Dated this 20th day of August 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.