Year: 1889

page_text: Date of Application, 16th Apr., 1889
Specification Accepted, 1st June, 1889
We, JAMES MADISON POLLARD, Gentleman, PHILIP GRAY RUSSELL and HENRY
ORTH, Patent Agents, all residing at the City of Washington, County of Washington,
District of Columbia, United States of America, namely, at Number 810 12th. Street,
Numbers 515 and 529 7th. Street, North West, respectively, 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 :-
Our invention is especially designed for small pulleys, though applicable to any
diameter, and is an improvement in the mode of fastening the parts together and to
the shaft with which, or upon which, it is to rotate.
Split pulleys have become almost indispensable because of their application to shaft-
ing already in place without the necessity of taking down the shaft and removing
other pulleys etc., as in the case of solid pulleys, but it has heretofore been found
impracticable to make split pulleys of less than twelve (12) inches diameter because of
the lack of room for fastening bolts etc. A few split pulleys have been made of
nine (9) and ten (10) inches diameter, but at great expense and inconvenience, and
these pulleys were lacking in strength because the rims were necessarily very thin to
adınit of room for the fastening bolts and nuts with which the parts are clamped or
drawn together.
The objects of our invention are to dispense entirely with the latter-to construct a
split pulley of any desired size, down to the smallest used, even if but two or three
inches in diameter, to dispense entirely with metal in any form when making wood
pulleys, and to so construct the parts that they will firmly interlock with each other,
and while binding the rim securely together will also frictionally clamp the hub upon
the shaft with the requisite degree of force to dispense with spline or key or set screw,
or other fastening device.
A further object of our invention is to produce a pulley of the greatest possible
strength, simplicity of construction, ease of manufacture and application, and least
possible number of parts.

page_text: we attain these objects by the mechanism illustrated in the accompanying drawings,
in which—
Figure 1, is an end view of a pulley constructed according to one of the best forms
of our invention.
Figure 2, is a side view partly in section on the dotted lines, x, x, of Figure 1.
Figure 3, is an end view of a pulley showing a modification, and
Figure 4, a plan of the upper half, and elevation of the lower half, of the bushing
for same.
Figure 5, is an end view of another modification, and
Figure 6, a side view of the same, partly in section on the. dotted lines, y, y, of
Figure 5.
Figure 7, is an end view, enlarged, of a pulley similar to that shown in Figure 1.
Figure 8, is an end view of another modification.
Figure 9, is a similar view on a reduced scale of a large pulley with our invention
adapted thereto.
Figure 10, is an isometric perspective of one half of the rim of the pulley shown
in Figure 7.
Figure 11, is a side view of the bushing and shaft of pulley shown in Figures 7
and 10, the bushing being shown applied to the shaft and in vertical section lengthwise
of the latter.
Figure 12, is an end view of a very small wood pulley with iron bushing. In each
of the end views we have shown in dotted lines the thickness of bushing and rim at
the other end of the pulley, thus indicating the wedge or incline of the parts, and
Figure 13, is a similar view of one of our split pulleys in which the rim is made to
bind upon the shaft.
It will be seen that our pulley consists essentially of four parts, viz.: of two duplicate
portions constituting the hub or bushing, and of two duplicate portions constituting
the rim, and that the construction is such that when the bushing, as in Figure 11,
drawn end wise into the rim shown in Figure 10, the wedge form of the parts binds the
bushing tightly together or closes the two halves towards each other and upon the
shaft. At the same time the two halves of the rim are also drawn forcibly together
by the transverse dove-tail inclines of the bushing so that the parts are held together
and to the shaft with a force or friction grip exactly proportioned to the force used in
driving the parts together, all of which will now be specifically described.
A, A, in the drawings, are the two halves of the rim, and these, as before stated, are
exact duplicates of each other so that a description of one will suffice.
As shown in Figure 3, the rim is grooved or channelled out to any requisite length,
the vertical face of this groove, a, a, being parallel to the axis of shaft, C, and of equal
depth from end to end of the pulley; that is to say, of equal depth at all points from
the vertical central dividing plane of the pulley rim. The upper and lower portions of
this mortise or channel are, however, tapered from end to end, in two planes, as shown
in the dotted lines which indicate the dimensions of both mortise and bushing at the
other end of the pulley. The bushing, B, in Figure 4, shows in plan, the inclines, a¹, a',
which serve by their wedge form to draw the two halves of the pulley together, and in
elevation, the incline, b, or wedge, by means of which the rim forces or draws together
the two halves of the bushing.
This form would be inconvenient to manufacture, and is shown and described merely
because it illustrates better than any other form the double wedge action of the device.
The curved or hollowed incline shown in Figures 1, 2, 7, 10 and 11, and the dove-tail
incline shown in Figures 5, 6, 8 and 9, are exact equivalents in their mode of action.
The two parts of the bushing are either cut apart with a thick saw, after having been
bored out for the shaft as a whole, or are separated a short distance when being bored,
or when made separately as we design, the bore in each half is less than the half of a
circle so that when applied to a shaft the bushings cannot come in contact with each
other and the entire wedge action is sustained by the shaft. It will be seen that a
machine need only be designed to make half bushings and half rims. We prefer in
practice to construct small pulleys as shown in Figures 7, 10 and 11, and larger sizes,

page_text: or those above one foot in diameter somewhat as shown in Figure 9. By the first
named plan the rim is left of greater thickness at the points, a, a, Figures 5 and 7,.
and the bushings are more readily intorchangeable. The rim is built up solidly of
layers of wood glued and pressed together with the grain of alternate layers crossing
each other at a right angle and to a thickness to form the requisite width of face or
length of pulley; it is then cut or split into two equal halves or parts and dadoed out
for the bushing.
The latter is bored to the requisite size for the shaft and shaped exteriorly like the
mortise in the rim when the two parts are placed together. The fit between the sides
of the bushing and the sides, a, a, of the mortise in the rim is not so close as to bind.
with any force even when the parts are forcibly driven together, while the bushing is
upon its wedge surfaces slightly wider vertically than the mortise so that it cannot be
driven in flush with the end of the pulley. The grain of the wood in the bushing is trans-
verse to the shaft and at right angles with the division line or plane of the rim sections,
as shown by the lines in Figure 1. It will thus be seen that the tensile strength of
the wood in the bushing is available for holding the rim against centrifugal action and;
for rotating the shaft or pulley, as the case may be, that the tensile strength of half
the layers of the rim is exerted to pull the rim sections together, and that the tensile
strength of the remaining rin sections is exerted in drawing the bushings together
upon the shaft.
In practice we have found it best to place the bushings in position upon the shaft.
and to drive the rim sections upon them by striking the halves alternately with.a
mallet. There is no danger of splitting the rim and no difficulty in securing a grip
upon the shaft that is amply sufficient to perform any possible amount of work without
slipping. Instead of driving the parts together they may be drawn and secured by.
bolts and nuts passing from the thick end of the bushing on a line parallel at all points
to the axis of the shaft and engaging the opposite ends of the pulley rim, or by any.
other suitable means, but we have found this unnecessary in practice and so do not
illustrate or claim such means
な
It is designed to make the bushing externally of but two or three sizes for all small
pulleys, for instance, a standard size and taper for pulleys, 5, 6, 7 and 8, inches in
diameter, and another for pulleys 9, 10, 11 and 12 inches in diameter. For smaller
diameters special plans will be made. By this means the bushing will be inter- :
changeable and may be bored and kept in stock to fit various diameters of shafting.
When pulleys of great width of face are required, they may be made to taper from
each side to the center and the bushing of standard sizes driven from each end, two
sets of bushings being used for each rim in such case.
While we have described a wood pulley, we do not at all limit ourselves to the use
of this or any other material. For specially small pulleys where a comparatively large
bore is required, an iron bushing may be used, as shown in Figure 12.
Instead of making the mortises in the rim and the exterior of the bushings incline
or taper lengthwise of the pulley, these parts may merely be dovetailed and tightened
upon the shaft by means of dowel pins or wedges or bolts, as indicated at, K, of
Figure 12, but these methods would be inferior to the methods we have adopted for
practice and are entirely within the intent of our invention.
Many other modifications of form might be devised that would accomplish the same
results and be entirely within the spirit and scope of our invention, and we have not.
attempted to show, or even to devise them.
We also intend to make loose pulleys, as shown in Figure 12, and to do this by
lining, the bushing with Babbitt metal and using space blocks, b', 6', between the .
edges of the two parts of the bushing, so that the pressure derived from the wedge
action of the parts shall be borne by the bushings coming in contact with each other.
and not upon the shaft. These space blocks can then from time to time be reduced in
thickness and the bushings brought close together, thus compensating for wear.
In our pulley, as shown in Figure 13, instead of having the bushing alone engaging
the shaft, we draw the sides of the pulley rim against the shaft, so as to bind thereon..
This pulley we make with the shaft opening of a diameter from, a³, to, a³, less.

page_text: than the diameter of the shaft by the thickness of the said cut by which the pulley
is split.
The bushings, B, B, which draw the pulley halves together, are to be shaped
substantially like those shown and described hereinbefore, but are narrower so as to
engage with their inner sides only small portions at the periphery of the shaft.
Space is thus left for the inner sides of the two pulley halves to engage and bind
upon the shaft.
In full lines in Figure 13, the sides of the narrow bushings, B, B, are shown as
substantially parallel with each other. If desired, we contemplate, however, making
then, as shown in dotted lines in said Figure, with their sides, as seen in end view
sloping from their outer portion away from each other.
Our invention can, obviously, be applied to the fastening of wooden or metallic
rim upon a pulley or wheel as well as to the placing of a pulley on a shaft.
In such case the rim, being in two halves and provided with any one of the
described forms of bushing ways or grooves, is fastened or bound upon the exterior
of the pulley or wheel by bushings corresponding in shape with the ways in the rim.
Our split pulley is also capable of use as a shaft coupler. As indicated in dotted
lines in Figure 6, it can be so placed as to bind at the same time upon the contiguous
ends of two shafts in line with each other.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is―
1st. In a split pulley, the two part rim and two part bushing provided with inter-
locking ribs and grooves adapted to draw and lock the half rims together as they
are forced endwise upon the bushing, substantially as and for the purposes
specified.
2nd. A split or separable pulley consisting of two duplicate portious constituting
the hub or bushing and having inclined or wedge surfaces, whereby it is made self"
fastening, and tightening by the act of forcing the parts together, as set forth.
.
3rd. A split or separable pulley having interior doubly inclined mortises and a
separable bushing having exterior doubly inclined surfaces and bored to fit over or
upon a shaft, as set forth.
4th. In a split or separable pulley, the two part rim and the wooden bushing adapted
to hold the rim parts together having the grain of its wood at right angles to the shaft
opening in the bushing, and to the plane of division of the rim into its two parts,
substantially as and for the purpose shown.
5th. In a split or separable pulley, the two part bushing with each part having a
doubly inclined wedge shape, being tapered uniformly from end to end, and having
on its inner side a longitudinal groove to partially enclose a shaft, and on the outer
side being grooved, dove-tailed or channelled longitudinally, in combination with the
two half rims having their inner sides shaped to fit the bushing so that as the rim and
bushing are moved longitudinally with reference to each other, the parts of the rim
will be drawn together and the parts of the bushing will be forced towards each other,
substantially as and for the purpose specified.
6th. In a two part split pulley, the two parts of the rim each having a dove-
tailed or equivalent undercut mortise, in combination with a two part split bushing
shaped exteriorly to tit said mortise, substantially as set forth and described.
7th. In a two part split pulley having a dove-tailed or equivalent undercut wedge
shaped mortise in each part, a two part split bushing shaped exteriorly to fit said
mortise and bored to fit over or upon a shaft, the construction being such that when
the bushing or other parts of the pulley are being put together, the bushing draws
and holds the two parts of the rim forcibly together, and the rim draws and holds
the two parts of the bushing firmly upon the shaft, as shown and described.
8th. In a split or separable pulley in combination with the two halves of the pulley
rim formed of layers of wood glued and pressed together, the grain of the alternate
layers crossing each other and having undercut wedge shaped mortises in each half,

page_text: a separable bushing formed of wood and having the longitudinal fibres or grain
crossing the bore at a right angle thereto, whereby the tensile strength of the wood
of the bushing is available for drawing the two parts of the rim together or towards
each other and the tensile strength of a part of the wood composing the rim is
available for drawing the two parts of the bushing towards each other, as shown
and described.
9th. A split or separable pulley made in two equal or like halves united and held
together solely by a split or separable bushing, substantially as described.
10th. A split or separable bushing made in two equal and like halves, in combination
with a rim also made in two equal and like halves, the bushing forming the sole con-
nection between the two halves of the rim, and the rim forming the sole connection
between the two parts of the bushing, as set forth.
11th. In a split pulley in combination with the tapering bushing divided longi-
tudinally into two parts, each part provided on its outer side with a longitudinal
groove or channel diminishing in width towards the smaller end of the bushing, the
pulley rim divided into two parts on a longitudinal plane at right angles to the plane
of division of the bushing, each part rim being provided on its inner side with ribs to
engage the opposite sides of the grooves in the outer sides of the bushing, substantially
as and for the purpose described.
Dated this 16th day of April 1889.
JAMES MADISON POLLARD.
PHILIP GRAY RUSSELL.
HENRY ORTH.
By Jensen & Son,
77, Chancery Lane, London, W.C.,
Patent Agents.