An Improved Gearing for Transmitting Rotary Motion.
Year: 1899

page_text: Date of Application, 5th May, 1899-Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
An Improved Gearing for Transmitting Rotary Motion.
I, VLADIMIR DE LEMLENIN ISGOY, of No. 77, Westbourne Grove, Bayswater, in
the County of London, W., Milliner, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement:-
My improvement relates to gearing and has for its principal object to construct
an improved intermittent gearing in which the back-lash is reduced to a minimum
and the motion of the driven shaft begins and ceases without jerk or shake, my
invention is however applicable to continuous gearing.
In one form of intermittent gearing hitherto employed a pin on the driving
wheel engages in succession the teeth or rays of a star wheel on the driven shaft
so that said shaft is rotated a certain portion of a revolution for every revolution
of the driving shaft. This gearing has, however, the great disadvantage that,
the driving pin which is revolving at a uniform rate, strikes against the star
tooth at the beginning of the engagement therewith, and the shock of the impact
causes a jerk or jar to be given to the driven shaft which is very objectionable.
According to my invention in place of the driving pin' I provide on the driving
wheel a driving projection of suitable form to engage with the teeth of the driven
wheel, one edge or end of said projection being, however, located substantially
at the centre of the driving wheel. The two wheels are located in such position
relatively to each other that the points, of the teeth of the driven wheel pass over or
in close proximity to the centre of the driving wheel during the revolution of
the driven shaft, and in order that the beginning and the end of the movement
of the driven wheel shall be very slow, so as to avoid shake or jar, I arrange that
at the time when the outermost edge of the driving projection leaves the route of
the driven teeth, the innermost edge shall make contact with the point of the
next tooth on the driven wheel. It is clear that more than one driving projection
may be provided on the driving wheel and these may be so located with reference
to each other that the motion of the driven wheel is continuous.
In order that my invention may be clearly understood, I have shewn in the
accompanying drawings a number of forms of driving and driven wheel con-
structed in accordance with my invention.
Figure 1 is a plan, and
Figure 2a side elevation of a pair of wheels in gear.
Figures 3, 4, and 5 shew various positions of the pair of wheels illustrated in
Figure 1, and
Figures 6 to 13 are diagrams shewing various forms of teeth.
a is a driving wheel provided with a projection b, and c is the driven wheel.
The driving wheel is mounted on the end of its shaft & because the points of the
teeth of the driven wheel c pass over its centre.
Referring now to Figures 1 to 5.
Figure 1 shews the relative position of the driving projection b and the teeth of
the driven wheel e just before said wheel e has begun to be driven, the arrow
showing the direction of rotation of the driving whool

page_text: In Figure 3 the driven wheel has been rotated in the direction shewn by the
arrow, thereon, but it will be seen that owing to the form of the driving pro-
jection b, only a small amount of angular motion will be given to the wheel c
due to a considerable movement of the wheel a.
In Figure 4 the projection b is in the most favourable position for driving the
wheel c, and consequently if the rotation of the driving wheel a be uniform the
wheel c will be driven at its greatest velocity at this point.
In Figure 5 the movement of the wheel e has just ceased and the inner edge
of the driving projection has met the point of the next tooth on said wheel so
that its further movement is stopped.
It will be seen moreover, that just before the stoppage of the movement of the
wheel c its motion will be exceedingly slow owing to the shape of that part of the
driving projection and the portion of the tooth of the wheel c then being driven.
In order to absolutely prevent movement of the driven shaft except at those times
when the driving face of the projection is in contact with the following face of
a tooth of the wheel c, I provide a disc e on the driving shaft adapted to engage
with circular concavities in a wheel f on the driven shaft, the disc e has a portion g
thereof removed as shewn in Figure 1 of the drawings so as not to prevent motion
of the driving shaft at such times when the wheel c is being driven by the pro-
jection b. This arrangement is one wellknown to persons skilled in the art.
The remaining figures of the drawing shew various designs of teeth, all of
which have features in common with those shewn in Figures 1 to 5, namely, that
the movement of the driven wheel c begins very slowly and ends very slowly.
This is due to the fact that the driving face of the projection b in every case
extends approximately to the centre and the point of said face which first makes
contact with the driven face of a tooth of a wheel e will be close to the centre
of the wheel a and therefore be moving very slowly. Consequently, the beginning
of the movement of the wheel c will in all cases be very slow. Furthermore, the
end of the movement of the wheel will also be very slow, because as will be
seen from an inspection of the drawings the last portion of the driven surface
of a tooth of the driven wheel e will just before the end of the movement be
very nearly tangential to the path of movement of the last portion of the driving
face of the projection b, consequently, the movement of said driven wheel will
at this period he very slow.
It will be clearly understood that the angular velocity of the driven shaft will
not be uniform throughout the period of movement of said shaft, in fact, one of
the objects of my invention is to prevent this occurring, and to arrange that
the said shaft shall have a greater angular velocity during the middle portion
of its movement than it has at the beginning and end of its movement.
It is obvious that in some designs more than one driving projection may be
provided on the driving wheel, so that the driven wheel will receive a rotary
movement twice or more often during every rotation of the driving wheel depend-
ing on the number of driving projections, and these may be so arranged that the
driving wheel is given a continuous motion.
My improved gearing may be used for a variety of purposes where motion is
required to be communicated from one shaft to another, for example, it will be
found useful in mechanisms for producing the wellknown kinetoscope effects in
magic lanterns, photographic apparatus, scientific instruments, guns, printing
machines, propellers, clock movements and many other machines of this
description.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A gearing in which the points of the teeth of the driven wheel pass over or
in close proximity to the centre of the driving wheel during the revolution of the
driven shaft, the driving wheel being provided with one or more driving pro-

page_text: jections, the driving face or faces of which extend substantially to the centre
of the driving wheel, whereby at one period of the movement of the driven wheel,
the point of contact between the driving projection and the driven tooth will be
caused to move very slowly.
2. Gearing constructed substantially as described with reference to any of the
forms shewn in the accompanying drawings.
A
1000
W. P. THOMPSON & Co.,
822, High Holborn, London, W.C.,
Patent Agents for the Applicant.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C.,
Patent Agents for the Applicant.