Year: 1896

page_text: Date of Application, 10th Oct., 1896
L
C
711
14007
25th Cont
1007
I, ARCHIBALD SHARP, Engineer, 13 Fairlawn Grove, Chiswick, in the County
of Middlesex, do hereby declare the nature of this invention to be as follows:-
In my invention the rim of the pulley is made from a straight plank or planks,
of wood planed approximately to the required section, then steamed and bent
into a ring of the required diameter. The ends of the wood rim abut against each
other and are fastened by screws to a cover-plate of metal or wood on the inner
surface of the rim.
Tangent-spokes of steel wire or rod may be used to connect the rim to the nave,
the ends of the spokes at the rim being secured by screwed nuts or nipples lying
in holes countersunk beneath the surface of the pulley; as in a tangent-spoke
bicycle wheel. I prefer to make the tangent-spokes in pairs from one length of
wire or rod, as described in Patent Specification No. 3617 of the year 1892. When
the pulley is built, the rim may be turned true in a lathe.
For pulleys that cannot conveniently be placed endways on the shaft, the nave
may be in halves, which are fastened together by bolts when placed in position on
the shaft; the ends of the rim are sprung apart sufficiently to pass over the shaft,
and are jointed by the aforesaid cover-plate; the spokes are then placed in position
and the nuts screwed up until the rim is concentric with the shaft.
A pulley, required to be split into halves without detaching the spokes from the
nave and rim, may be built with spokes capable of resisting thrust; such spokes
may be of wood or of metal tube. Or, the spokes may be of wire made in pairs;
each pair lying in a groove on the outer surface, or wrapped round a projection
from the face of, the nave.
tobon 1006
I, ARCHIBALD SHARP, Engineer, 13 Fairlawn Grove, Chiswick, in the County
of Middlesex, 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:-
T
invention the rim of flat halt nulloy is made from a straight planl
a

page_text: or planks, of wood planed approximately to the required section, then steamed
and bent to the required curvature. The ends of the wood rim abutting against
each other may be fastened by a suitable dovetail or other joint, or by a cover-
plate of metal or wood on the inner surface of the rim, to which the said abutting
ends may be secured by screws.
In a pulley for rope driving the rim may be made of two or more thicknesses
of planks steamed and bent as above described and then glued together. The
grooves for the ropes are turned in a lathe when the pulley is built.
The nave or hub may be of iron, of wood, of compressed paper or wood pulp, or
of any other suitable homogeneous material.
Tangent-spokes of wood, metal tube, or other material suitable for resisting a
compressive stress are used to connect the rim to the nave. The spokes are screwed
simultaneously to the rim and to the nave, the screw at the nave being of smaller
diameter than that at the rim, but both screws being of the same pitch. The
spokes are spread laterally at the nave or hub, as in a bicycle wheel.
A pulley required to be split into halves without detaching the spokes from the
rim and nave is made with the nave and rim each in halves fastened together by
bolts, and with the spokes of wood, or of metal tube.
When the pulley is built, the rim may be turned true in a lathe.
In order that my invention may be clearly understood I append drawings, in
which corresponding parts are similarly Tettered.
Figures 1 and 2 are views, partly in section, showing a split belt-pulley with
8 wooden spokes. The rim R may be of uniform thickness, or may be made
thicker in the middle where the spokes are screwed in its edges e, and outer
surface being turned true in a lathe after the pulley is built up. The inner
surfaces r, may also be turned true, before the cover-plates C are fixed. The cover-
plates C are screwed to the rim by the screws S with lock-nuts n; the inner central
ridge of the rim being removed for the cover-plate. The cover-plate may be per-
manently fastened to one portion of the rim. The halves of the nave N are
fastened together by the bolts and nuts B. The spokes or arms A. are placed so
that their centres all lie at the same distance from the centre line of the shaft,
their ends screwed into the nave are smaller than their ends screwed into the rim.
The mouth of the holes in the nave are made plain, to fit tightly the bodies of
the spokes.
To facilitate the building of the pulley, the angle between the spoke and the
rim both longitudinally and transversely, is preferably the same for all. There
will be four series of spokes at different distances from the face of the nave, as
shown diagramatically at A1, A2, A3, A' (Fig. 1). One half of the spokes A1, A3, A5,
go to one end of the nave, and the alternative spokes A3, A4, A6,
to the other end; the spokes are then grouped in sets of four in the front elevation
(Fig. 2). The plane of division of the rim and nave should pass between adjacent
sets; the number of spokes in a symmetrical split pulley should therefore be a
multiple of 8.
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 A pulley for belt or rope driving constructed with bent-wood rim, and
tangent spokes of wood or other suitable material capable of resisting compressive
stress substantially as herein described.
2. A split pulley for belt or rope driving, comprising a divided nave the parts
whereof are adapted to be detachably secured to each other and to a suitable shaft,
a rim made up of two or more pieces of bent-wood with the abutting ends adapted
to be detachably jointed together, and tangent-spokes of wood or other suitable
material capable of resisting compressive stress, the said tangent spokes being

page_text: screwed simultaneously to the nave and to the rim; substantially as herein
described and illustrated in the accompanying drawings.
Dated this 6th day of August 1897.
G. DOUGLAS LEECHMAN,
18 Hertford Street, Coventry, 75 Chancery Lane, London, W.C., and
49 Middle Abbey Street, Dublin, Patent Agent for the Applicant.