Improvements in Pulleys for Driving Machinery.
Year: 1889

page_text: Date of Application, 2nd Aug., 1889
Complete Specification Left, 23rd Apr., 1890-Accepted, 24th May, 1890
PROVISIONAL SPECIFICATION.
Improvements in Pulleys for Driving Machinery.
I HENRY LEA, of the firm of Henry Lea and Thornbery of No. 38 Bennetts Hill
Birmingham in the County of Warwick Consulting Engineers, do hereby declare the
nature of this invention to be as follows:-
My invention has reference to improvements in the construction of pulleys my said
improvements being especially applicable to pulleys for driving dynamos and other
quickly running machines in which it is necessary to use pulleys of comparatively small
diameters and in which it is also desirable to reduce the slip of the belt as much as
possible and at the same time to employ a slack belt in order to avoid undue friction
on the bearings of the machine.
Pulleys constructed according to my invention are however applicable to all purposes
to which ordinary pulleys are applicable.
In carrying my invention into effect I use a metallic pulley secured upon the shaft
or spindle in any well known manner. I make the body of the metallic pulley
somewhat smaller in diameter than that of the finished pulley. At one side of the
pulley I form a metallic shroud or flange of the same or of somewhat less diameter
than that of the finished pulley. At the other side of the pulley I provide a loose
shroud or collar of the same diameter as the other fixed shroud or flange. The said
loose flange is capable of sliding endwise upon the body of the metallic pulley but
has a small key or check pin to compel it to rotate with the metallic pulley.
Between the fast, and loose shrouds or flanges thus formed I place a series of annular
discs or rings of leather or other flexible and yielding material side by side the said
discs filling up the space between the two shrouds or flanges. At equal distances
around the fixed shroud I drill a series of holes preferably six or eight parallel to the axis
of the pulley the loose shroud and discs having similar holes. 1 provide a corresponding
series of screw bolts and nuts and passing the said bolts through the fixed shroud,
discs and loose shroud by means of the screw nuts I compress the said discs between
the two metallic shrouds. I then turn the edges of the said discs in a lathe to the
required diameter of the pulley either making the face convex or leaving it cylindrical
as may be preferred.
I sometimes modify my invention in the following manner. I provide two fixed
shrouds to the metallic body of the pulley and between the said shrouds I coil a long
strip of leather or like material cut spirally from the hide or sheet. During the
process of coiling which by preference is done by the pulley being slowly rotated in
a lathe I maintain a tensional strain upon the strip by drawing it through a clamp
and I apply a strong cement to the strip as it passes onto the metallic pulley. At
the beginning and ending of the strip I either taper the strip sideways to fill the
tapering space between the first coil and the adjoining shroud or I give each of the
shrouds themselves an inclined face terminating in a shoulder against which the end
of the strip abuts in which case I do not taper the end of the strip itself. pin or
screw the leading end of the strip to one shroud of the metallic pulley so as to enable
the pulley when placed in the lathe to draw the strip through the clamp and after
completing the winding on of the strip I sometimes insert ordinary woodscrews
passing through holes in the metallic shrouds and screwing into the material of the
coiled strip. When the cement has set I turn the exterior of the pulley true in the lathe
as already described.
Pulleys made according to my invention present the edges of the discs or strips to
the action of the driving belt and afford a grip with a slack belt which cannot be obtained.

page_text: satisfactorily in any other way. The efficiency of a machine driven by pulleys made
according to my invention is materially increased and the driving belts may be run
with advantage very slack which renders them more durable and reduces the wear
and tear of the bearings.
Dated this 2nd day of Amanst 1990
W. T. WHITEMAN,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Pulleys for Driving Machinery.
I HENRY LEA of the firm of Henry Lea and Thornbery of No. 38 Bennett's
Hill Birmingham in the County of Warwick Consulting Engineers, do hereby
declare the nature of this invention and the manner in which the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
My invention has reference to improvements in the construction of pulleys; my
said improvements being especially applicable to pulleys for driving dynamos and
other quickly running machines in which it is necessary to use pulleys of com-
paratively small diameters and in which it is also desirable to reduce the slip of the
belt as much as possible and at the same time to employ a slack belt in order to avoid
undue friction on the bearings of the machine.
Pulleys constructed according to my invention are however applicable to all
to which ordinary pulleys are applicable.
purposes
In carrying my invention into effect I use a metallic pulley secured upon the shaft
or spindle in any well known manner. I make the body of the metallic pulley
somewhat smaller in diameter than that of the finished pulley. At one side of the
pulley I form a metallic shroud or flange of the same or of somewhat less diameter
than that of the finished pulley. At the other side of the pulley I provide a loose
shroud or collar of the same diameter as the other fixed shroud or flange. The said
loose flange is capable of sliding end wise upon the body of the metallic pulley
but has a small key or .check pin to compel it to rotate with the metallic
pulley.
Between the fast and loose shrouds or flanges thus formed I place a series of annular
discs or rings of leather or other flexible and yielding material side by side the said
dises filling up the space between the two shrouds or flanges. At equal distances
around the fixed shroud I drill a series of holes preferably six or eight parallel to the
axis of the pulley, the loose shroud and discs having similar holes. I provide a corre-
sponding series of screw bolts and nuts and passing the said bolts through the fixed
shroad, discs and loose shroud by means of the screw nuts I compress the said discs
between the two metallic shrouds. I then turn the edges of the said dises in a lathe
to the required diameter of the pulley either making the face convex or leaving it'
cylindrical as may be preferred.
I sometimes modify my invention in the following manner.
shrouds to the metallic body of the pulley and between the said shrouds I coil a long
I provide two fixed
strip of leather or like material cut spirally from the hide or sheet. During the
process of coiling, which by preference is done by the pulley being slowly rotated in
a lathe, I maintain a tensional strain upon the strip by drawing it through a clamp and
I apply a strong cement to the strip as it passes onto the metallic palley. At the
beginning and ending of the strip I either taper the strip sideways to fill the tapering
space between the first coil and the adjoining shroud; or I give each of the shrouds
themselves an inclined face terminating in a shoulder against which the end of the
strip abuts in which case I do not taper the end of the strip itself. I pin or screw
the leading end of the strip to one shroud of the metallic pulley so as to enable the
pulley when placed in the lathe to draw the strip through the clamp and after

page_text: completing the winding on of the strip I sometimes insert ordinary wood screws
passing through holes in the metallic shrouds and screwing into the material of the
coiled strip. When the cement has set I turn the exterior of the pulley true in the
lathe as already described.
Pulleys made according to my invention present the edges of the discs or strips
to the action of the driving belt and afford a grip with a slack belt which cannot
be obtained satisfactorily in any other way. The efficiency of a machine driven
by pulleys made according to my invention is materially increased and the
driving belts may be run with advantage very slack which renders them more
durable and reduces the wear and tear of the bearings. And in order that my
invention may be the better understood I will proceed to describe the same
with reference to the accompanying drawings and the letters and Figures marked
thereon.
In all the Figures the same letters of reference denote the same parts.
Figure 1 Sheet 1 is a front view of a pulley made according to my invention
the upper half being in section on the line It S (Figure 2) and the lower half in
elevation.
Figure 2. Sheet 1. is a side view of the same pulley the upper half being in section
on the line T U (Figure 1) and the lower half being in elevation.
Figure 3 (Sheet 2) is a side view of the body or main part of the pulley
the upper half being in section and the lower half being in elevation similarly to
Figure 2.
Figure 4 (Sheet 2) is a front view of one of the leather discs shown
detached.
Figure 5 (Sheet 2) is a side view of the same.
Figure 6 (Sheet 2) is a side view shewing a method of guarding the edge of the
pulley at V Figure 2 but drawn the reverse hand. The nut of the screw bolt in
Figures 6 and 8 is on the shrouded side of the pulley.
Figure 7 (Sheet 2) is a partial front view of the guard ring.
Figure 8 shows the end of a screw bolt with cottar pin and guard ring in
section.
Figure 9 (Sheet 1) is a front view of a pulley made according to a modification
of my invention, part of the upper half being shown in section on the line W X
(Figure 10) and the remainder in elevation.
Figure 10 is a side view of the same pulley the upper part being in section on the
line YZ (Figure 9) and the remainder in elevation.
Figure 11 is a side view of the body of the pulley shown in Figures 9 and 10.
I will first describe the pulley as I prefer to make it and as illustrated in
Figures 1 to 7.
12
a is the body of the pulley made usually of cast iron bored in the usual manner
for placing on the driving shaft and turned truly cylindrical on the rim a'. It
has a projecting flange or shroud a² in which are holes for the serew bolts d, d
to pass through. I prefer to turn the body of the pulley all over both inside and
outside for the sake of obtaining proper "balance in running. b, bare rings of
leather or other like material which if the size of the pulley allows of it are each
made in one piece but if this is impracticable then in pieces properly spliced and
cemented as shown at b in Figures 4 and 5. Each of these leather rings has a set
of holes 62, 6 punched in it for the screw bolts d, d to pass through. I cut the
rings b, b slightly larger than requisite for the purpose hereinafter explained and
punch the holes 62, 62 to a template so as to ensure their exact uniformity: c is a
metallic ring or washer which is slipped on the body of the pulley and is made of
somewhat less external diameter than the leather rings b, b. The said metallic ring
or washer c has holes in it corresponding to the holes 63, 6' in the leather rings.
The metallic ring c is prevented from rotating on the body of the pulley by one or

page_text: more small keys c¹ or other suitable means; d, d, d are screw bolts which pass through
the holes in the metallic ring e and those in the leather rings b, band in the shroud a
of the body of the pulley. These screw bolts d. d are provided with nuts d', d¹
which when tightened up compress the rings b, b so that they practically become
a solid mass.
To ensure that the nuts d¹, d shall not come off while the pulley is running I use
one of several well known means preferably making the screw bolt to project
well through the nut and inserting a split pin as shown in Figure 8.
At the high rate of speed at which pulleys made according to my invention are
intended to be used it becomes important io avoid any projections the rapid motion of
which might be dangerous to an attendant or bystander. therefore make the heads d², d
of the screw bolts d. d either as smooth hemispherical projections as shown in
Figure 2 or as cylindrical heads countersunk into the shroud a as is well
understood.
To protect the nuts I use a guard ring e Figures 2. 6. 7 and 8 which has circular
apertures e, e, e¹ for the reception of the nuts d', d'. The guard ring e is attached
to the washer ring c by means of countersunk screws at e², e Figure 7. In putting
the pulley together I first put the bolts d, d, d in their places; then I slip
on the first leather ring 3 Figure 2. I then slip on the next leather ring and I
may cement it to the first ring by means of either common or marine glue or
I may omit the cementing and simply slip on the second ring bringing it into close
proximity to the first and so on until all the leather rings b, b, b have been put on.
I then slip on the metallic rings c and then screw on and tighten up the nuts d', d'
of the bolts d, d.
Having thus by pressure and cementing, or simply by pressure, practically brought
the leather rings to the condition of a solid mass, I place the pulley in a lathe and
take a cut over the outer edges of the said rings turning them to the exact required
diameter and making the face either flat or convex as may be desired. The fixing of
the guard ringe is the last process. This ring not being an essential part of my
Invention may under certain circumstances be dispensed with as for instance when
the pulley is fenced in or otherwise efficiently protected.
In the modification of my invention illustrated in Figures 9, 10 and 11, I form
upon each side of the body a of the pulley a shroud or flange a³, a³ and 1 apply the
leather in the form of a long coiled strip the necessary length being obtained by
cutting the strip spirally from a skin of leather and in some cases by glueing or
cementing together two or more of such strips placed end to end. I fasten one end
of this strip Figure 10 to the recessed part of the shroud a³ Figure 11 by
means of a screw as shown in Figure 10 and I then place the pulley in a lathe and
slowly wind the strip tightly upon it glueing or cementing the strip as I proceed
to that part already wound. The inner faces of the shrouds a', a have a holical
shape so as to ensure that from beginning to end the strip shall assume a truly
helical position and shall solidly and accurately occupy all the space between the
shrouds.
Through the shrouds I drill countersunk holes a, as Figures 9 and 10 and when
the leather strip has been wound on and the glue has set I drill corresponding holes
in the leather and insert wood screws which secure the glued leather from slipping
round on the body of the pulley. Finally I put the pulley in the lathe and turn
down the face of the leather so as to form either a flat or curved face as hereinbefore
described.
as my
Having now particularly described and ascertained the nature of my inven-
tion and the manner of performing the same i declare that I claim
invention of "Improvements in pulleys for driving machinery ":-
First Covering metallic pulleys with leather or other like material in such a

page_text: manner as to present the edge of the material to the surface of the driving belt for
the purpose and substantially as herein before described and illustrated in the
accompanying Drawings.
Secondly-The combination of the shroud-the metallic ring-and the screw
bolts and the nuts-with the rings or strip of leather or other like material for the
purpose and substantially as herein before described and illustrated in the accom-
panying Drawings.