Year: 1897

page_text: I, CHARLES ORTON HALL of Neave Building, Cincinnati, Ohio, U.S.A., President
of Manufacturing Company, 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 :-
In the accompanying drawing Fig. 1 is a side elevation of a sprocket wheel and
chain constructed in accordance with this invention; Fig. 2 a plan view of the chain;
Fig. 3 a longitudinal section of the same; Fig. 4 a side view of a portion of the
larger one of the sprocket wheels; and Fig. 5 details relating to the sprocket chain.
A, A¹ are sprocket wheels with teeth a projecting from their rims in the form of
segments, to provide curved bearing surfaces which may extend across the periphery
of the wheel as indicated in Fig. 4, or may project centrally therefrom as indicated in
Fig. 1 so as to give a peripheral margin on each side of the teeth upon which the
outer links of the chain may bear, and in practice the smaller sprocket wheel or pinion
will have peripheral margins while the larger or driving wheel A¹ will have a narrow
periphery with the teeth extending entirely across it.
Bare the central links of the chain, the end portions of which are curved, to
correspond with the segmental teeth on the wheels A, A¹ and the side edges of these
links are curved to correspond with the periphery of the wheels or that portion thereof
between the segmental teeth.
In constructing sprocket wheels for use with a chain, it is considered essential that
the links B should fit closely upon the periphery of the wheel and against the
segmental teeth thereof, and therefore the periphery of the larger sprocket wheel
should be made to correspond with the periphery of the smaller; in other words, the
periphery of the larger sprocket wheels between the segmental teeth, instead of being
a true circle, should correspond with the bearing surfaces b of the links B.
The links B are made of flat pieces, provided with apertures B' presenting V shaped
projections B2 the point in one recess projecting towards the point in the other recess
of the link. These links are connected to side links C by means of transverse pins C¹
having centrally enlarged portions c which are concave on one side and convex on the
other (Fig. 5), the ends of said enlarged portions presenting shoulders c¹ against
which the side links Û bear, the ends of the pins being upset upon said links after the
parts of the chain are placed together. It will be noted that the width of the central
portion c of the links C¹ correspond with the thickness of the central links B, also
that the pins are held in engagement with said links.
In a chain thus constructed there will be but little friction, as the direction of the
strain will bring the bearings upon the point or knife edges, so that a chain of this
character will run freely and require but a small amount of lubrication. In use the
side links of the chain do not come in contact with the periphery of the larger or
driving wheel A¹ but merely lie over the sides of the sprocket teeth, the central links
fitting between the sprocket teeth and impinging against the same. The curved
edges of the links C are shaped so that the edges which engage with the rim or

page_text: periphery of the smaller sprocket wheel, are of the same radius of curvature as the
marginal projecting rims of said wheel; also the edges of the central links have a
concave bearing surface of the same radius of curvature as the peripheries of the
sprocket wheels, and their end concave bearing surfaces the same radius of curvature
as the sprocket teeth. The chains and sprocket wheels of this invention run very
easily with but a small amount of wear upon the parts, and such wear instead of having
a deleterious effect upon the chains and wheels, improves them.
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. In combination, sprocket wheels of different diameters, the smaller having
curved sprockets and marginal projecting rims, the larger having sprockets and a
periphery which is made up of said sprockets and bearing surfaces or segments, the
curve of which has the same radius of curvature as the marginal rim of the smaller
wheel; together with a chain having central links with curved bearing surfaces which
are adapted to contact with the sprockets and faces of the sprocket wheels, and outer
links, the contacting edge of which has the same radius of curvature as the marginal
projecting rims of the smaller sprocket wheel, substantially as described and shewn.
2. A sprocket chain made up of a series of central links, having edges shaped to
present three concave bearing surfaces, the central bearing surface having the same
radius of curvature as the peripheries of the sprocket wheel, the end concave bearing
surfaces having the same radius of curvature as the sprockets and outer links, the
contacting edges of which are shaped to correspond with the periphery of the smaller
sprocket wheel, for the purpose specified, substantially as described and shewn.
3. In combination with the sprocket wheels having convex sprockets, a chain
having central links for engagement with said convex sprockets, the end portions of
the links where they engage with the sprockets being concave, and an intermediate
concave bearing edge, substantially as described and shewn.
4. A sprocket chain composed of a series of central links and side links connected
thereto, the central links having concave end bearing portions adapted to engage the
periphery of the sprocket teeth, snbstantially as described and shewn.
Deted this 17th day of May 1897.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C., Agent for the Applicant.