A NEW APPARATUS FOR TRANSMITTING MOTION AT VARIABLE SPEEDS
Year: 1881

page_text: LETTERS PATENT to David Young, of 23, Southampton Buildings, in the
County of Middlesex, Consulting Engineer and Patent Agent, for an Invention
of "A NEW APPARATUS FOR TRANSMITTING MOTION AT VARIABLE SPEEDS."
A communication from abroad by Edouard Brosser, of Paris, in the Republic
of France.
PROVISIONAL SPECIFICATION left by the said David Young at the Office
of the Commissioners of Patents on the 8th November 1881.
DAVID YOUNG, of 23, Southampton Buildings, in the County of Middlesex,
Consulting Engineer and Patent Agent. "A NEW APPARATUS FOR TRANSMITTING
MOTION AT VARIABLE SPEEDS." [A communication from abroad by Edouard
Brosser, of Paris, in the Republic of France.]
This system is applicable to all machines requiring little force, and which are
worked by the feet, such as lathes, fret saw machines, or sewing machines, and also
to other machines, and consists essentially in the employment of two shafts, each
provided with a convex disc, the one shaft being driven by the motor, and the
other by the frictional contact of the two discs, which are adjustable for trans-
mitting motion at variable speeds. The second shaft transmits the motion to the
machine to be driven at a speed regulated by the adjustment of the said discs.
The mechanism, according to one method of carrying this Invention into practical
effect, consists of a base plate provided with two standards which are hollowed out
to form guides. Through these guides in the two standards pass two shafts with
their bearings, the latter fitting between the guides. Each of these shafts carries a
pulley at one end, and is provided between the bearings with a convex disc, one of
which discs is covered with a skin or hide fixed by means of screws or by other
suitable means. One bearing of each shaft is pivotted while the other is free to
move up and down between the guides. The raising and lowering of the latter
bearing is effected by means of a lever connected to a rod by a single and double
eye or other suitable joint, and actuated by a treadle. This rod bears against the
underside of the free bearing of the lower shaft, and its travel is regulated by a

page_text: ring fitting on and secured to it. The free bearing of the upper shaft is above the
pivotted bearing of the lower one, and is attached to it by means of a spring. The
convex sides of the two discs face each other, and rings are fitted and secured upon
the shafts on each side of the bearings to keep the shafts in their desired positions
and regulate the adjustment of the discs. The position when at rest should be
such that the two discs are as near together as possible without touching each
other, and for this purpose the free bearing of the upper shaft rests upon a
support fixed to the standard, against which it is drawn by means of the aforesaid
spring.
The operation of this mechanism is as follows:-Supposing it to be applied to a
sewing machine, the pulley on the lower shaft would be connected to the motor by
a belt, and the pulley on the upper shaft connected to the sewing machine in the
same manner. Under these circumstances the motor would be constantly turning
the lower shaft with its disc, and when the sewing machine is to be started the
free bearing of the lower shaft is raised by the lever, as before described, thereby
bringing the smaller diameter of its disc in contact with the larger diameter of the
disc on the upper shaft, and transmitting motion to the sewing machine. The
more the free bearing of the lower shaft is raised the more will the speed of the
upper shaft be accelerated. To stop the sewing machine it is only necessary to
allow the lower disc to fall out of gear with the upper one.
This system has the great advantage of producing promptly any desired
variation in the speed, and of enabling a machine to be stopped or started
instantaneously, and that without fatigue to the person working it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Young in the Great Seal Patent Office on the 8th May
1882.
DAVID YOUNG, of 23, Southampton Buildings, in the County of Middlesex,
Consulting Engineer and Patent Agent. "A NEW APPARATUS FOR TRANSMITTING
MOTION AT VARIABLE SPEEDS." A communication from abroad by Edouard
Brosser, of Paris, in the Republic of France.
This Invention relates to apparatus for transmitting motion at variable speeds,
and capable of being applied to machines requiring a small amount of force, and
which are worked by the feet or by other power, such as lathes, fret-saw machines,
sewing machines, and others. The said apparatus consists essentially in two shafts
suitably supported in bearings, and each provided with a convex disc, the one
shaft being driven by the motor, and the other by the frictional contact of the two
discs, which are adjustable for transmitting motion at variable speeds. The second
shaft transmits the motion to the machine to be driven at a speed regulated by the
adjustment of the said discs.
In the accompanying Drawing,
Figure 1 is a sectional elevation of an apparatus constructed according to the
said Invention.
Figure 2 is an end view; and
Figure 3, a plan or top view of the same.
Figure 4 is a sectional elevation of a modified construction of the said
apparatus.
Figure 5 is a front elevation of the standards or guides; and
Figure 6 is a section the line x, x, Figure 5.
Like letters indicate the same parts throughout the Drawing.'
A is a base plate upon which are cast or fixed two brackets or standards B, B,
which are hollowed out or otherwise made to form guides C, as shewn in Figure 2.
Between these guides are fitted blocks D, D', and E, E, which form bearings for
carrying the shafts F, F', upon which are secured the convex discs G, G', and tho
grooved pulleys H, H¹.
According to one method, which is illustrated in Figures 1, 2, and 3, the blocks
or bearings D and E are pivoted within the guide C of the brackets or standards B,
and the pulleys H, H', are secured upon the ends of the shafts F, F, outside of
these bearings. The blocks or bearings D¹ and El are free to slide within the
guides C. The bearing D¹ may be raised or lowered at will by means of a lever
(not shown in the Drawing) connected to the rod K by a single and double eye
or other suitable joint, and actuated by a treadle. The rod K bears against the
underside of the free bearing D' of the lower shaft F, and the travel of the said
rod is regulated by a ring or collar K' fitting on and secured to it. The free
bearing E of the upper shaft F' is above the pivotted bearing D of the lower
shaft F, and is attached to it by means of a spring J. The rings or collars a, b,
are fitted and secured upon the said shafts at each side of the bearings to keep
the shafts in their desired positions, and to determine the distance between the
two discs. The noriual position of the shafts F, F', should be such that the two
discs are as near together as possible without touching each other, and for this
purpose the free bearing of the upper shaft is arranged to rest upon a support L
fixed to one of the standards B, against which support the said bearing is drawn
by means of the spring J.
A modification in the construction of the apparatus is shown in Figures 4, 5,
and 6. The two standards B, B, are enlarged at c, c, so as to enable them to carry

page_text: the pivots or pins d, d, of the bearings D and E. I also modify the form of the
grooved pulleys H, H', so that a line drawn through the centre of the pivots d
will pass through the centre of the grooves on the pulley. By this means,
whatever may be the speed imparted to the discs, the belts have always a uniformn
tension upon them, and the strain upon these belts is thus reduced as much as
possible. With this object I also diminish the distance between the two
standards B. The spring J is carried in the recesses J'.
When the above described apparatus is applied to a machine, the pulley on the
lower shaft is connected by means of a belt or cord to a pulley on the motor or on
a shaft worked by a treadle, and the pulley on the upper shaft is connected in a
similar manner to the sewing machine or other machine to be driven. Under these
circumstances the motor may be constantly turning the lower shaft F with its
disc G, and when the sewing machine is to be started the free bearing D¹ of the
lower shaft is raised by the lever, as before described, thereby bringing the smaller
diameter of the disc Ġ in contact with the larger diameter of the disc G¹ on the
upper shaft F', and transmitting motion to the machine.. When the bearing D¹ is
thus raised it lifts the shaft F¹ and bearing E', and thereby expands the spring J.
The more the free bearing of the lower shaft is raised the more will the speed of
the upper shaft be accelerated, until the discs are brought into the position
indicated by the dotted lines k in Figure 1. When in this position, if the speed is
found to be too great, it may be diminished by lowering the shaft F and disc G,
the spring J operating to keep the two discs in contact.
The disc G is preferably covered with leather or other material, which is fixed
upon it by means of screws or in any well known manner, for the purpose of
increasing the friction between_the_two_discs. _To_stop_the-machine-it-is-only-
necessary to allow the lower disc to fall out of gear with the upper one.
This apparatus has the great advantage of producing promptly any desired
variation in the seed of a machine, and of enabling such muchine to be stopped or
started instantaneously and without fatigue to the person using it.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. The apparatus constructed, arranged, and operated, substantially as set
forth, for enabling the speed of a sewing-machine, lathe, or the like, to be varied
at will.
Second. In an apparatus for transmitting motion at variable speeds, the two
convex discs fixed upon shafts mounted in bearings capable of being oscillated
within guides, in the manner and for the purposes substantially as set forth.
Third. In an apparatus for transmitting motion at variable speeds, the com-
bination with the shafts mounted in bearings and carrying the convex discs
of a lever and connecting rod, whereby the said bearings may be oscillated within
the guides, and the spring, whereby the said bearings are caused to resume their
normal position, substantially as set forth.
Fourth. In an apparatus for transmitting motion at variable speeds, the peculiar
arrangement and construction of the pulleys and guides, whereby a uniform tension
upon the belts is maintained, substantially as set forth.
In witness whereof, I, the said David Young, have hereunto set my hand and
seal, this Eighth day of May, in the year of our Lord One thousand eight
hundred and eighty two.