Improved Speed Variation Gear.
Year: 1896

page_text: Date of Application, 18th Jan., 1898
Complete Specification Left, 16th Oct., 1896-Accépted, 9th Jan., 1897
PROVISIONAL SPECIFICATION.
Improved Speed Variation Gear.
WILLIAM EDWARD GIBBON Engineer 25 Mersea Road Colchester do hereby
declare the nature of this invention to be as follows:---
My invention relates to any of the suitable clutches now in use, or any specially
designed device 'for transmitting power, in which the driver and the driven are
coupled together in the following manner. Upon the driver I fix a suitable spring
or springs in a rigid manner, with the free end or ends pointing forward in the
direction of rotation, and such' end or ends pressing against the driven part; such
end or ends may be the spring or springs themselves, or may have loose or fixed
pads or surfaces of different metals or materials to further increase the frictional
power between the end or ends and the driven body. A suitable device of levers
and screws is so arranged that the pressure exerted by the free end or ends can be
regulated 'at' will or'thrown out of contact completely, or the length of the spring
or springs temporarily altered' so as to increase or reduce the time of vibration.
By these means there is always 'a vibration of greater or less speed between the
free' end' or ends of the spring or springs and the diiven face, in proportion, to
the pressure with which 'the free end or ends, press on the driven face, and the
amount of work done by the driven face or mechanism, thus enabling the driver to
impart motion at any 'desired speed up to and including equal speeds to be driven
mechanism without slip and wear, as in the ordinary friction clutches.
Dated this 17th day of January 1806
Improved Speed Variation Gear.
I, WILLIAM EDWARD GIBBON, late of 25, Mersea Road, now of 96, Military
Road, Colchester, in the County of Essex, Engineer, do hereby declare the nature
of this invention and 'in'wbat 'manner the same is to be performed to be particularly
described and ascertained in and by the following statement':-
This invention relates to a device for 'transmitting power at variable' speed and
has for its object to provide 'a device wherein the lip and wear which occur 'in
such devices as hitherto constructed can be obviated.
:
According to my invention I rigidly secure to the driven (or driving) part of
the device for transniitting motion one end of a spring or of a number of springs.
Each spring is arranged so that it extends in a direction opposite (or similar) to
that in which the driver'rotates and so that its free end can come in contact with
the driver or driven part of the device. The free end of each spring is preferably
provided with a pad or the like of suitable material to increase the friction
between the surfaces in contact and suitable means, such as a lever, are provided
for throwing 'the spring or springs into and out of contact or to regulate the
pressure of the same on the surface opposed to the spring or springs. In some
cases 1 provide means for increasing or reducing the length of the spring or
springs so as to reduce or increase the time of vibration of the said spring or
springs.

page_text: With this construction it will be obvious that, when the free end of a spring is
pressed against the surface of the driver. or driven part of the device, the said
spring will be caused to vibrate, the time of vibration varying with the pressure
exerted by the spring and with the amount of work done by the driven part of
the device, so that the speed imparted to the said device can be varied as desired,
that is to say, it can have imparted to it a speed equal to or below that of the
driver.
To enable my invention to be fully understood I will describe it by reference to
the accompanying drawing, in which :-
Figure 1 is a sectional elevation of a clutch device constructed according to my
invention:
Figure 2 is a section on the line 2-2 of Figure 1.
a is the driver half of the clutch and b the driven half of the same, the said
halves being mounted on the shafts a' and ' respectively. c, c, c are the springs
secured at one end to the driven part 6 of the clutch by means of pins d, d, d
passing through the same as shewn clearly in the drawing. The springs c, c,.c
extend from the pins d, d, d in a direction against that of the rotation of the
driver as shewn clearly in Figure 1, in which the arrow indicates the direction in
which the driver a rotates. The periphery of the driver a is provided with a
facing of wood e and the free end of each spring is also fitted with a pad or block f
of wood or other suitable material to increase the friction.
The springs c, c, c are so mounted on the pins d, d, d that their rear ends project
therefrom as shewn clearly in Figure 1. 9, 9, 9 are bell-crank levers pivoted to
the driven part band, the shorter arms of which project through slots h in the
said driven part 6 of the clutch and extend underneath the projecting rear ends of
the springs c, c, c.. The longer arm of each bell-crank, lever 9 is connected to a
sleeve i on the shaft b' so that by. sliding the said sleeve on the shaft the shorter
arms of the levers g force the free ends of the springs c, c, e against the periphery
of the driver with greater or less pressure or allow the said springs to entirely
leave the said periphery.
It will be obvious, as above described, that, when the blocks or pads' fare
pressed against the periphery e of the driver a, which rotates in the direction of
the arrow Figure 1, the springs c, c, c will be caused to vibrate at a rate depending
on the ratio between the pressure due to the frictional contact and the resistance
of the load on the driven part b, that is to say, they will rotate the driven half b
of the clutch at a speed depending on their rate of vibration and also on the work
to be done by the said driven part b, such speed being anything up to that of the
driver..
It is to be understood that the springs can be secured to the driver, and be so
arranged that their free ends make contact with the driven part of the device.. In
this case they project in the direction of motion of the driver.
.
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. In devices for transmitting motion at variable speed, coupling the driving
aud driven parts of the devices, by means of a spring or springs rigidly secured at
one end to one of the parts and free at the other end, the said, free end being
adapted to come in contact with and be vibrated by the other part, substantially
as, and for the purpose, hereinbefore described.
2. The combination and arrangement of parts forming the improved variable
speed gear herein before described and illustrated in the accompanying drawing.
Dated this 15th day of October 19nc
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant..