Improvements in Elastic Pulleys.
Year: 1893

page_text: Date of Application, 23rd Nov., 1893
Complete Specification Left, 18th Aug., 1894-Accepted, 22nd Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in Elastic Pulleys.
I, JAMES TURTLE, Mullavilla House, Tandragee, in the County of Armagh,
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention is designed to provide an elastic pulley for driving machinery to
prevent any uneven or jerky movement of the motor such as is experienced in a
gas engine being transmitted to the machine.
It consists essentially in constructing the pulley double or of two parts one inside
the other connected together by springs one being attached to the crank or driving
shaft of the motor and the other being loose thereon the motion from one to the
other being conveyed through the springs.
In carrying out the invention I construct the elastic pulley in the form of two
pulleys one placed inside the other. The inner one is a strong pulley keyed to
the crank or driving shaft of the engine. The outer one is preferably made in two
halves bolted together so as to enclose the inner one the diameter of the outer one
being about 25% greater than the other.
On the periphery of the inner pulley are placed snugs and on the under side of
the rim of the outer pulley are placed corresponding snugs. To these snugs are
attached spiral or other springs both in tension and compression which connect the
two inner and outer pulleys together.
The springs thus arranged have both a pull and a push and are adjusted
according to the load on the engine, or the power which they are intended to
transmit.
When the inner pulley is bolted to the shaft the rims of the two parts of the
outer pulley are bolted together thus forming a rim of sufficient width for the belt.
Instead of dividing the rim of the outer pulley into two parts the rim of one may
extend over the arms at one side and of the other at the reverse side and thus
one pass inside the other, and if desired the outer pulley may be keyed to the shaft
and the other be loose upon it. The springs may be of spiral or other form and
rubber packings or springs may be employed to assist metal ones.
By this invention I consider that all jerkiness or unevenness in the motion
transmitted from the engine will be taken up and compensated for by the springs
whilst an even movement only will be transmitted from the pulley to the machine
or machinery being driven.
Dated this 22nd day of November 1893.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Elastic Pulleys.
1, JAMES TURTLE, of Mullavilla House, Tandragee, in the County of Armagh,
Manufacturer, 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 elastic driving pulleys such as are used with gas engines
or other motors with an uneven or jerky movement to prevent such being
transmitted to the machine or machinery being driven.

page_text: It consists essentially of the combination of two pulleys or parts of pulleys one
placed inside the other, the inner one being attached to the crank shaft or driving
shaft of the motor and the outer one loose thereon, the two being connected
together by a spiral spring or springs through which the movement of one is
conveyed to the other.
It will be fully described with reference to the accompanying drawings.
Fig. 1. Longitudinal sectional elevation.
Fig. 2. Transverse sectional elevation.
Fig. 3. Longitudinal section of modified construction.
Fig. 4. Side elevation of same.
I construct the improved pulley of two parts, one placed inside the other. The
inner part A is keyed to the crank shaft C of the engine or motor, or to other
driving shaft so as to rotate therewith. The outer part B is placed loose on the
driving shaft C and is about 25% greater than the inner one A, the rim or
flange extending out over the inner part A preferably sufficiently far to
completely enclose or cover it. The outer part of the pulley B may if desired be
made in two halves with a boss on either side of the inner pulley A so that by
bolting the two halves of the part B together the part A will be completely
enclosed.
In the arrangement shown in Figs. 1 and 2 the inner part A is made in the form
of a complete pulley with a rim a extending round the periphery.
In the modification shown in Figs. 3 and 4, the inner part A is made triangular
or with three arms a¹ to which the springs are attached.
On the periphery a of the inner part A or on the extremities of the arms a¹ are
placed snugs d and on the underside of the rim 6 of the outer part B are placed
corresponding snugs d¹. To the snugs d d¹ are attached spiral springs D which
connect the inner and outer parts A and B of the pulley together and through
which the motion from one to the other is transmitted. The springs D are
preferably so placed or arranged as to resist both compression and extension.
springs may be of spiral or other form and rubber packings or springs may be
employed to assist metal ones.
'The
The inner pulley or part A being keyed to the driving shaft C the movement of
the shaft is transmitted through it and through the springs D to the outer pulley
or part B upon which the driving band is placed any jerkiness or unevenness in the
motion transmitted from the engine is first taken up by the springs which expand
and gradually return to their normal position thus transmitting a much more even
movement from the pulley to the machine or machinery being driven.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An elastic pulley constructed of two parts one placed inside the other and
connected together by spiral or other springs the inner part being keyed or other-
wise secured to the driving shaft and the outer part loose upon the driving shaft
substantially as described.
2. An elastic pulley having the several parts arranged in combination together
substantially as described and shown.
Dated this 17th dov of A
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.