Improved Arrangements of Pullies and Bands and Friction Wheels for Driving Machines from Electromotors.
Year: 1892

page_text: Date of Application, 6th Sept., 1892
Complete Specification Left, 24th May, 1893-Accepted, 24th June, 1893
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. SIEMENS & HALSKE, of Berlin, in the
German Empire, Electrical Engineers.]
Improved Arrangements of Pullies and Bands and Friction Wheels
for Driving Machines from Electromotors.
We, SIEMENS BROTHERS & CO. LIMITED, of 12 Queen Anne's Gate, Westminster,
in the County of Middlesex, Electrical Engineers, do hereby declare the nature
of this invention to be as follows:-
This invention relates to the arrangement of the pullies and bands by which
machines, such as lathes and the like, are driven from electro-motors, the chief
object in view being to provide for sufficient tension and grip of the driving bauds,
without requiring between the axes of the driving pullies, the intermediate pullies
and the driven pullies, such distances as are usually necessary when driving is
effected by bands.
For the purpose of the invention, the electro-motor is mounted on the end of a
lever arm which its weight tends to depress, the axis of the intermediate pulley,
which is situated above the electro motor and is driven by a band from the electro-
motor, is mounted in bearings on a lever arm connected to a treadle or handle by
which it can be raised, and on this intermediate axis is a pulley, (which may be a
stepped pulley) driving by a nearly horizontal band the pulley on the shaft of the
lathe or other machine.
The lever arm carrying the electromotor may be in its normal condition
horizontal or nearly so, but the lever arm which carries the axis of the intermedinte
pullies is inclined upwards from its pivot, this inclination being so selected that the
tension of the band from the motor to the intermediate is equal or in any desired
proportion to the tension of the band from the intermediate to the machine.
By releasing the treadle or handle which maintains the tension of the bands, they
can at once be loosened, and thus a band can be readily shifted from one step to
another.
In cases where the machine is driven by friction wheels, the intermediate axis is
so mounted that the strain is directed towards the driven axis and not away from
it as when the driving is by a band.
Dated this 6th day of September 1892.
ABEL & IMKAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Arrangements of Pullies and Bands and Friction Wheels
for Driving Machines from Electromotors.
We, SIEMENS BROTHERS & CO. LIMITED, of 12 Queen Anne's Gate, Westminster,
in the County of Middlesex, Electrical Engineers, 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 the arrangement of the pullies and bands by which
machines such as lathes or the like, are driven from electromotors, the chief object
in view being to provide for sufficient tension and grip of the driving bands without
requiring between the axes of the driving pullies, the intermediate pullies and the
Iriven pullies such distances as are usually necessary when driving is effected by
bands. Some of the arrangements which we shall describe for this purpose are

page_text: applicable also when driving is effected through friction wheels, and in all cases
the parts are so arranged as to give facilities in altering the speed of the driven
machine when desired.
The
As shown in Fig. 1 a pulley r on the shaft of an electromotor E drives by band R
a pulley on the shaft Z on which is a stepped pulley driving by band Ra
stepped pulley on the shaft A of the lathe or other driven machine.
electromotor E is carried on a lever arm pivotted at O and the bearings of the
shaft Z are in a pair of lever arms H pivotted at O', so that the weight of the electro-
motor and of the arm carrying it strains the band R and strains also the band R',
the relative strain ou cach band being determined by the angular position of the
arms H, which position can be selected so as to proportion these strains as may be
desired. By means of a treadle lever which is connected by a rod to the
lever arms H, these arms can be moved on their pivot O', so as to bring the two
stepped pullies 273 nearer to one another, thus facilitating the shifting of the
band R from one pair of steps of the pullies to another pair, when it is desired
to alter the speed of the machine A..
According to the modified arrangement shewn in Fig. 2 the shaft Z carries a
stepped friction wheel driving a stepped wheel on a intermediate shaft B
which revolves in fixed bearings. A band R² strained by a weight W passes over
one or other of the steps of 2 so as to be interposed between the peripheries of
and. When it is desired to alter the speed of the driven machine, the shaft Z is
raised, it may be by a treadle as in Fig. 1, and the band R2 is shifted from one
step of to another.
As shown in Fig. 3, the electromotor E' and an intermediate pulley driven
from it by worm gear, are carried on the lever arm H which, as in Fig. 1, can be
raised by treadle and rod for the purpose of shifting the band R¹ from one
pair of steps to another. For working rapidly revolving machines, the worm gear
and intermediate pulley may be dispensed with, as shewn in Fig. 4.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim in respect of pullies and bands and friction wheels for driving machines from
electro motors is :-
1. Mounting the electromotor on a lever arm so pivotted that the weight of the
motor and arm strains the band by which the motor drives the machine or an
intermediate pulley or friction wheel, substantially as described.
2. When an intermediate pulley is employed, mounting it on a lever arm having
an inclination suited to the relative strains of the two bands, substantially as
described.
Dated this 24th day of May 1893
ABEL & IMRAY,
Agents for the Applicants.