Improvements in and relating to Speed Pulleys.
Year: 1893

page_text: Date of Application, 5th Dec., 1893-Accepted, 6th Jan., 1894
COMPLETE SPECIFICATION.
Improvements in and relating to Speed Pulleys.
J, WILLIAM MATTHEWS MINTYRE of Wilkinsburg in the County of
Allegheny and State of Pennsylvania, United States of America, Mechanical
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 :-
This invention relates to improvements in what are known as speed pulleys, by
which varying rates of speed may be communicated with a given rate of motion of
the shaft with which the pulley is connected.
The object of the invention is to provide an improved device of the above
character which shall possess superior advantages with respect to efficiency in
operation.
The invention consists in the novel construction and combination of parts herein-
after fully described and claimed.
In the accompanying drawings
Figure 1 is a side elevation showing two pulleys constructed in accordance with
my invention, connected together by a belt, and showing means for shifting the
slidable parts of the pulleys.
Figure 2 is a similar view looking from the opposite side.
Figure 3 is a cross sectional view on line x-x in Figure 1 and
Figure 4 is a perspective detail view to be hereinafter referred to.
In the said drawing, the reference numeral 1 desiguates a driving shaft formed
with a number of equidistant horizontal grooves 2. This shaft is journalled in the
frame of a machine or in standards or hangers as may be required. In the present
instance it is shown as having its bearings in standards 3. Fixed to the shaft 1 is
a series of triangular shaped segments 4 with alternating spaces 5 which register
with the grooves in the shaft. Located in the grooves of the shaft 1 are slides 5ª
provided with similar segments 6. There are thus formed two cone shaped parts,
divided into segments or sections, the cones pointing in opposite directions and the
segments of one part fitting and slidable in the spaces between the other cone
or part.
Located below the shaft 1 is a similar shaft 7 having horizontal grooves 8.
Fixed to this shaft are segments 9 forming a cone similar to that above described
and in the grooves in the shaft fit and work slides 10 provided with segments 12
arranged to slide in the spaces between the segments 9.
The two pulleys above described are connected by a belt 13, and one end of
each of the slides 5 and 9 is connected with or secured to a standard 14. This
standard has apertures near each end through which the said shafts pass and is
horizontally slidable or movable thereon. Secured to this standard are guide
rods 15 and a supporting bar 16, which pass through holes in one of the standards 3
and are connected together by a bar 17.
Pivoted to the machine frame or base 18 is a lever 19 provided intermediate its
ends with arms 20 which embrace the belt 13. To the upper end of this lever is
pivoted one end of a connecting bar 21 the other end of which is pivotally con-
nected with the sliding standard 14. The outer ends of the movable segments are
connected by a band 23.
The operation will be readily understood. When it is desired to vary the speed
of the driven pulley the lever 19 is moved to the right or left which will actuate
the standard 14 which in turn will move the cones comprising the pulleys in or
out. Supposing for instance it is desired to increase the speed of the driven

page_text: pulley the lever (Fig. 1) is turned to the right, causing the standard 14 to be
moved outward or away from the cones, and the slides 10 to be correspondingly
moved, thereby increasing the circunference of the driving pulley. At the same
time the slides of the lower pulley will be operated to decrease the circumference
of this pulley. To accomplish this object it is necessary that the points of the
sliding segments of one shaft should point in a direction opposite to the points of
the segments of the other shaft. By this construction, although the slides of both
shafts move in the same direction, yet the circumference of one pulley will be
increased while the other is diminished and vice versa. As the slides are thus
moved, the belt will be correspondingly shifted by the arms on the lever, the belt
line being at the junction of the two cones composing each pulley.
While I have described the pulleys as being arranged in pairs, a single pulley
may be used if desired, in this case a drop or friction pulley is necessary to keep
the belt taut.
I have also described the pulley as being composed of fixed and slidable segments,
but it is obvious that both sets of said segments may be made slidable if convenient
and desirable.
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 cone shaped parts made up of oppositely
arranged segments and alternating spaces, the segments of one part fitting and
slidable in the spaces between the segments of the other part, substantially as set
forth.
2. The combination with a shaft formed with a series of horizontal grooves and
the segments secured to said shaft with spaces between aligned with the grooves
in the shaft of the slides fitting in said grooves, and provided with segments
working in said spaces, substantially as set forth.
3. The combination with the shafts having horizontal grooves therein, the
segments fixed to said shafts, the oppositely arranged movable segments, the slides
fitting in said grooves with which said movable segments are connected, forming
upper and lower pulleys, and the belt connecting said pulleys, of the horizontally
movable standard to which said slides are secured, the guide rods and supporting
bar, the lever, the shifting arms and the connecting bar, substantially as and for
the purposes set forth.
Dated this 4th day of December 1893.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.