Improvements in and connected with Pulleys of Variable Diameter.
Year: 1896

page_text: Date of Application, 16th June, 1896-Accepted, 1st Aug., 1896
COMPLETE SPECIFICATION.
Improvements in and connected with Pulleys of Variable Diameter.
WILLIAM MATTHEWS MCINTYRE of Edgewood Park, Allegheny County,
Pennsylvania, U.S.A., Engineer, 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 and accompanying drawings:-
This invention relates to what are known as speed pulleys, by means of which
varying rates of speed may be communicated with a given rate of motion of the
shaft from the source of power with which the pulley is connected and the present
improvements tend to simplify the construction and thereby cheapen the cost; to
reduce the weight, and to increase the efficiency of the device.
In the accompanying drawings, I have illustrated the pulleys and the supporting
frame therefor in plan view in Figure 1.
Figures 2 and 3 show perspective views of the parts of
the inner and outer face respectively.
one
Figure 4, is a sectional view through the supporting frame.
of the pulleys from
Figures 5, 54 and 5 show details of the construction of the means for moving
the slidable parts of the pulleys.
Figure 6 is a detail of the pulley.
Figure 7 is a sectional view of the belt.
In these figures, the frame is represented at A, and is composed of a piece of
angle iron bent into rectangular shape, the flange a being cut away at the position
of the corners, and brought together at a bevel. At the extreme end at one
corner, the flange a is removed entirely and the upright flange b laps the adjacent
flange to which it is securely bolted, as shown at the left hand upper end of
Figure 1. Thus a very simple construction of frame is provided of one piece having
a supporting flange a to which the bearings of the parts may be secured, and a
projecting flange b, which strengthens the entire structure.
To the flange a, the bearings c are bolted, and these bearings support a shaft d,
extending between the bearings. This shaft carries centrally. a double pulley
comprising one section e, secured to the shaft by a set screw, and a slidable
section y movable longitudinally of the shaft. These sections e, g, are of skeleton
form and consist of an annular ring 1, terminating in a hub 2, the hub being made
up of a series of divided parts with spaces between them and terminating at their
extreme outer ends in a ring 3, which unites these divided parts (see Figure 1
and detail Figure 5B). From the inner faces of the rings 1, extend cone shaped
plates tapering inwardly and terminating in horizontal projections 4, which find a
bearing on the shaft. Each ring 1, is provided with a like number of these cone
shaped tapering plates and the plates on one ring alternate with the plates on the
other and register with like spaces between adjacent plates, while the projections 4
register with the spaces 5, between the divisions of the hub. The skeleton form of
the rings and cone shaped tapering plates greatly reduce the weight and materially
increase the efficiency of the pulley.
A second double pulley is shown at B and is in all respects similar to the upper
pulley C, just described, but is reversed in position, so that the fixed part e is upon
The right hand side of the frame and the slidable part upon the left hand side and
it will be apparent that in changing the speed, as the slidable part of the lower
pulley is moved in one direction whether to increase or diminish the bearing
surface of the pulley, the slidable part of the upper pulley will be moved in the

page_text: same direction and will correspondingly increase or diminish the surface of its
pulley according to the direction of movement. The slidable parts are connected
together so as to be moved at the same time, and in the same direction. As the
cone shaped tapering plates interlock, it will be seen that a continuous bearing
surface is at all times provided, and as the movement of the slidable parts is
uniform and simultaneous, the belt or strap between the pulleys is kept constantly
centraily of the pulleys, and there can be no variation in the tension.
The fixed part of each pulley is provided with a band wheel i, and one may
receive power from the source of power, and the other communicate power to the
machine to be driven and if desired a loose pulley may be provided to shift the
belt, or one of the shafts may be extended and provided with pulleys.
I have provided a very simple arrangement for moving the oppositely placed
slidable parts of the pulleys, and incidental to the arrangement a very effective
connection between the moving parts or arms, and the hubs of the slidable sections.
As shown in Figure 5B, the ring 3 at the extreme end of the hub of the slidable
section is reduced to enter a recessed cap 6, and this cap (Figure 54) has projecting
from its rear face two projections 7, on each side of the position of the shaft.
A shifting rod 8 passes through the flanges 6 of the frame and the end of the rod
has a suitable connection with a shifting lever (not shown) which may be of any
ordinary or suitable construction. Secured to this rod 8 by set screws are two
arms 10, projecting in opposite directions, one extending to the hub of the slidable
section of the upper pulley and the other to the slidable section of the lower pulley.
These arms 10 are bifurcated and simply fit over the projections 7, and this completes
the connection. The caps 6 simply serve as an intermediate means between said
sections and the arms, for moving the slidable sections longitudinally. In the
shifting action of the rod 8, one of the arms has the effect of forcing inwardly the
slidable section of its pulley and this effect is communicated to the slidable section
of the other pulley through the action of the belt pressing against the inclined face
of the adjacent parts of the pulley. In order to adjust the tension of the belt, I have
provided a very simple form of tension device consisting of side pieces 12, resting
on the flanges a, and having the bearings of the lower shalt d formed integral
therewith, or secured thereto. The side pieces are connected at their lower ends
by an angle plate 13, and a threaded bolt 14, with a hand-wheel fitted thereto
extends from the angle plate 13, through the lower flange of the frame, and thus
the pulleys may be adjusted a distance apart in order to put a proper tension upon
the belt connecting them. The bifurcated construction of the arm 10 as shown in
Figure B, not only permits of this adjustment but is necessary to maintain the
operative relation of the parts regardless of the extent of the adjustment of the
supplemental frame.
The side plates 12, and connecting plate 13, form a supplemental frame which is
held in place by simply passing two bolts 15 through the flanges b above the side
plates 12.
In Figure 6 I show a section of one of the cone shaped tapering plates
strengthened by a web 16, this construction being desirable when large pulleys are
used for heavy work.
It will be understood that the variable speed may be communicated to the
machines to be operated through any desired arrangement of flat pulleys.
Any form of belt found desirable may be used but I prefer a belt of the cross
section of Figure 7 made of two or more plies of leather or suitable material, such
a belt conforming to the surface of the pulleys and being very effective in use.
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. A speed pulley consisting of two interlocking skeleton sections, each of said
sections comprising an elongated hub having a series of recesses extending length-
wise thereof, a ring extending from the front of each hub and a series of inclined

page_text: tapering segments in each ring alternating in position, the lower ends of the
segments fitting the recesses in the hub, substantially as described.
2. A speed varying device consisting of a main frame, a pulley carried thereby
comprising two interlocking sections one stationary and the other slidable, a
supplemental frame carrying a like pulley and movable in relation to the main
frame, arms for moving the slidable sections and an extensible connection between
one of said arms and the slidable section carried by the supplemental frame whereby
the adjustment of said frame is permitted without disconnection of the parts,
substantially as described.
3. In combination, a frame made up of angle iron, a shaft having its bearings
secured to one of the flanges, a supplemental frame composed of side plates and
carrying bearings for a second shaft, and a connection between them, supported ou
the Hange, retaining bolts passing through the flanges b above the side piates, and
means for adjusting the supplemental frame, substantially as described.
Dated the 15th day of June 1896.
For the Applicant,
E. K. DUTTON & Co.,
5 John Dalton Street, Manchester, Chartered Patent Agents.
E. K. DUTTON & Co.,
5 John Dalton Street, Manchester, Chartered Patent Agents.