from a Prime Mover Revolving in One Uniform Direction.
Year: 1888

page_text: from a Prime Mover Revolving in One Uniform Direction.
ARTHUR GERALD NICHOLS Mechanical Engineer of 21 Mincing Lane London E.C.
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:-
The object of my invention is that of readily obtaining a variable speed, or an
alteration in the direction of motion of a shaft, or other rotary mechanism from a
prime mover which itself is revolving in a uniform direction and at a constant
speed.
In order that the following description of the means I employ, may be more
easily understood, I attach drawings, showing the arrangement which I prefer
to employ..
Fig 1 is a plan.
Fig. 2 is a side elevation.
Fig. 3 is a side clevation of the mechanism in question:
Fig. 4 is an alternative method of reversing the direction of motion of the pulleys,
by shifting the centre of the revolving disc. The same lettering is employed in each
of the several views to distinguish the various parts.
Wherever it is difficult, if not impossible to reverse the motion of the prime mover,
as in the case of gas, petroleum, or other vapour engines, electric motors, or in other
instances where it may, from a variety of causes, be inconvenient to interfere with the
direction of motion or velocity of the primary means of propulsion; while it
is at the same time necessary to vary the speed or direction of the whole or
any part of the mechanism operated by the engines or motor in question.
I adopt the following plan:
The power developed by the prime mover is conveyed by means of the shaft a to
the disc b which, whenever in use revolves in a uniform direction as denoted by the
arrow mark on the drawing which accompanies this specification.
When it is required to convey this motion or power to any other mechanism this is
performed by means of one or other of the two friction pullies, C and C' which are
Fig. 2 is a side elevation.
Fig. 3 is a side clevation of the mechanism in question:
Fig. 4 is an alternative method of reversing the direction of motion of the pulleys,
by shifting the centre of the revolving disc. The same lettering is employed in each
of the several views to distinguish the various parts.
Wherever it is difficult, if not impossible to reverse the motion of the prime mover,
as in the case of gas, petroleum, or other vapour engines, electric motors, or in other
instances where it may, from a variety of causes, be inconvenient to interfere with the
direction of motion or velocity of the primary means of propulsion; while it
is at the same time necessary to vary the speed or direction of the whole or
any part of the mechanism operated by the engines or motor in question.
I adopt the following plan :
The power developed by the prime mover is conveyed by means of the shaft a to
the disc which, whenever in use revolves in a uniform direction as denoted by the
arrow mark on the drawing which accompanies this specification.
When it is required to convey this motion or power to any other mechanism this is
performed by means of one or other of the two friction pullies, C and C¹ which are

page_text: keyed to the shafts & and d' along which they can be moved by the lever H, their
distance of traverse being nearly equal to the radius of the disc b, so that by being
brought into contact with this disc the circumferential velocity of any portion of it
may imparted to either of them at will.
In their normal position these friction pullies are close up to the shoulder of
the long bearings E and E¹, their edges being at a small distance from the surface of
the disc b:
When the motion is required to be transmitted in one direction, the pulley C is, by
means of the lever J, brought into contact with the disc b, and when it is required in
the reverse direction the pulley (" is, in a similar manner brought into contact with
the other face of the disc, the pulley Ú being at the same time thrown out of gear, or
as in Figure 4 which is an alternative means of effecting the same object, cause
the disc to be brought into contact with either of the pulleys 'at will as it can be
traversed in either direction laterally by means of the lever.
For varying the speed of the pulleys, and hence of the mechanism connected
thereto, the pulleys are made by means of the lever H, to slide along the shaft in the
direction of the centre of the disc C so that any relative speed can be taken off at
right angles thereto.
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 :-
1. The use of frictional gearing as shewn when from the circumstance that the load
is a varying one, as in motion for tramways, hoists, or similar contrivances, it is
desired to vary the speed so as to employ the full power at slow speed where most
required as on steep gradients for tramway engines, and at a quicker speed when less
power will effect the necessary purposes, as on an easy gradient or level.
2. The use of the mechanism described for alternating speed and direction by the
employment of a disc rotating in a fixed path in combination with frictional gear
placed at right angles thereto.
.
3. Also the use of this frictional gear in conjunction with gas, petroleum, or vapour
engines, where it is difficult if not impossible to vary the direction and speed of
rotation of the prime motion or to start it from a state of rest.
Dated this 21st day of December 1888