Year: 1886

page_text: I, ARTHUR BRAMHAM PERKINS of the Forge, Thornton Road, Bradford, in the
County of York, Ironmaster, do hereby declare the nature of the said invention,
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:―
My invention consists principally in an improved form and arrangement of, the
spokes or arms of that class of pulleys or drums in which the boss and the spokes
or arms are formed of cast iron, and the rim of wrought iron or steel.
The improvement in the form of the spokes or arms of pulleys or drums referred
consists in " splaying"
or turning aside each of the spokes or arms, alternately to
the right and to the left of the central plane of the pulley or drum whereby
greater lateral strength is acquired than when the spokes are in or parallel to the
central plane of the pulley or drum.
In order that my invention may be fully understood, I will proceed to describe
the same with reference to the accompanying diagrams, in which Figure 1
represents a sectional elevation of a pulley constructed according to my improve-
ments, with straight splayed arms, and Figure represents a pulley constructed
upon a similar principle but with curved splayed arms. Figure 3 represents a
sectional elevation of the end of a spoke with the foot thereon and a portion of
the rim with my improved method of securing the joint of the rim and Figure 4
represents one of the double or forked spokes which are placed at the joining of
split pulleys constructed on my improved principle. Similar letters refer to
similar parts in all the diagrams.
In constructing pulleys or drums according to this invention the framework
consisting of the boss A the spokes or arms B and the feet C are formed in one
casting (or in the case of split pulleys in two castings, afterwards bolted together
in the usual manner). The framework thus formed is bored truly and the outside
of the feet C, which form the outward circumference of the framework are "trued"
up in the ordinary manner, in order that they may, when fitted inside the rim,
cause such rims to be in all parts equidistant from the axis of the boss. The
feet C and the rim D after being drilled are rivetted together, and the rough parts
of the rivets on the outer side of the rim are dressed off level with the surface of
the rim by grinding or milling.
By alternately splaying the spokes of pulleys or drums to the right and to the
left in the manner described great rigidity and lateral strength are obtained, in
consequence of the relative position of the spokes to the weight or pressure applied.

page_text: In order to make a secure joint at the opening or division in the rim of a
pulley, I make use of a joint plate E which is rivetted at F to the rim D at each
side of the division in the rim and the rivets G pass through the rim D the joint
plate E and the foot C thereby at the same time securing the joint and fixing the
spoke to the rim. I make the spokes or arms which abut upon a joint in the rim
as much shorter than the other spokes or arms as will allow for the thickness of
the joint plate E.
In making split pulleys or drums with splayed arms the spokes or arms at the
division of the two halves are bolted together to unite the two halves, and are
forked as represented at H and J in Figure 4 and bolt holes are cast in these
forked arms to facilitate the bolting together of the two halves.
The addition of the joint-plate E, or of a forked arm upon one side of the pulley,
will cause the pulley to be heavier upon that side to which such joint-plate or
forked arm is added.
To compensate for and balance the weight of the joint-plate or forked arm,
I make one of the spokes or arms on that side of the pulley which is opposite to
such joint-plate or forked arm, thicker and heavier than the other spokes or arms,
the weight of such thickened spoke to be determined by the weight of the joint-
plate or forked arm it is required to balance.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In the construction of pulleys or drums, forming the spokes "splayed" or
turned aside at an angle or curve alternately to the right and to the left of the
central planes of such pullies or drums.
2. In belt pulleys or drums, uniting the divisions in the rim by means of joint
plates rivetted to each side of the division and also rivetting through the rim, joint
plate, and foot of the spokes or arms of the pulley.
3. In belt pulleys or drums wherein the division of the rim is joined by a joint
plate, as herein described, making the spoke shorter which abuts upon the joint
plate to allow for the thickness of such plate.
4. In belt pulleys formed as herein described, balancing the joint plate and
forked arm as described by means of a thicker spoke on the opposite side or by
means of a detached balance weight.