Improvements in Driving Chains and Chain Wheels.
Year: 1897

page_text: Improvements in Driving Chains and Chain Wheels.
I, HENRY MALCOLM BIGWOOD, of 131, Penn Road, Wolverhampton, in the
County of Stafford, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to driving chains and chain or sprocket wheels, and it
consists in fitting the rollers of the chain with ball bearings, and in fitting the
teeth of the chain wheel with rollers running on ball bearings, the object being
to reduce friction.
According to my invention I form on or fix to the inner faces of the ends of the
alternate links or of one end of the link in case the chain is made up of links of
like pattern, male cones adapted with female cones or cups in the rollers to form
races for balls or spheres. The transverse pins performing no other function than
holding the links together.
The chain wheel has a roller mounted on each tooth, such roller forming either
both faces of the tooth or the driving face only. The periphery of the wheel is
formed as a groove between which the roller or rollers forming the teeth are
mounted on transverse pins, the parts being suitably coned or otherwise shaped to
allow balls or spheres to be interposed. When the driving faces only of the teeth
are provided with rollers I prefer to make the opposite faces of the teeth solid
but this is not obligatory.
ted this 14th day of July 1897.
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer & Patent Agent,
70, Chancery Lane, London, W.C., Agent for the Applicant.
Improvements in Driving Chains and Chain Wheels.
I, HENRY MALCOLM BIGWOOD, of 131, Penn Road, Wolverhampton, in the
County of Stafford, Engineer, 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:
-
This invention relates to roller driving chains and chain or sprocket wheels,
and consists in an improved arrangement of ball bearing for the chain rollers,
an improved arrangement of ball bearing for the wheel rollers, and an improved
construction of sprocket tooth which exposes a rolling surface at the side which
comes in contact with the chain during forward running, and exposes a solid
or rigid surface to the chain when the speed is being checked, as in back pedalling,

page_text: the purpose of such construction of tooth being to reduce the friction to a minimum
in forward driving and to insure increased frictional contact between the tooth
and chain when the speed is being checked.
In order that the invention may be clearly understood, I will describe the same
with reference to the drawings herewith, which illustrate the invention as applied,
by way of example, to the driving chain and chain wheel of a cycle.
Figure 1 is a sectional plan, taken through the centre of a short length of the
chain. For clearness of illustration, the parts are shewn to an enlarged size.
Figure 2 is a side elevation,, partly in section, of a portion of the sprocket wheel
and chain, the parts being shewn to a smaller size than the parts shewn by
Figure 1. Figure 3 is a transverse section through the rim of the wheel, and
through one of the roller teeth thereof.
Referring first to Figure 1, a is a short pin which joins together two links b b
and c c, and A is the roller around such pin. Recesses or cups, having bearing
paths or inner cones e, are formed in the side faces of the roller, and cones f
surround the pin a. Anti-friction balls g.are placed within the recesses formed in
the side faces of the roller, and as the roller revolves the balls travel between the
bearing paths of the cones f and the bearing paths e of the roller. The cones f
are either formed solid with the inner faces of the two sides of the link bb, as
shewn, or are let somewhat into such inner faces, as in the case of the cones f¹
which are shewn at the joint nearest to the right-hand end of the view. When,
as is preferred, the cones of a bearing are formed solid with the sides of the link bb,
it will be found convenient to form such cones by pressing out metal from the
sides of the link. This method of forming the cones leaves recesses in the opposite
faces of the link sides, which are however of no detriment to the chain.
The ball bearing of a roller is, of course, adjusted by means of the pin a. This
pin may be formed with a conical head h, and be provided with a conical nut i,
to fit, respectively, within corresponding holes in the outer sides of the link c c.
In lieu, however, of a pin and nut, a rivet may be used, as the wear may be taken
up by riveting; but in such case one of the countersunk holes (when such occur)
in the sides of the link cc, is, preferably, filled by a conical washer against the
outer face of which the riveted head bears.
Referring now to Figures 2 and 3, each tooth is fitted with a roller k formed with
recesses in its sides to receive anti-friction balls 7, as in the case of the chain rollers.
The balls run around a cone m formed upon a pin n, and around a cone p which
surrounds such pin. The pin n passes through ears q q' which project from the
rim of the wheel. The hinder end of the pin n fits within the hole formed
through the ear q, and has a head n¹ which comes against the outer face of such
ear. The cone is formed with a portion which is screwed through the hole
which is formed through the ear q¹, and the hinder end of the cone p is formed
with a flange s by means of which it is screwed through the ear q¹. A nut t is
screwed upon the end of the pin n, and is, preferably, tightened into a conical
countersunk recess in the back of the cone p, to securely lock the cones.
adjustment of the ball bearing of the roller is effected by first slackening the nut t,
then screwing the cone through the ear q₁ as may be required, and then screwing
up again the nut t. To prevent the pin from turning while the nut is being
screwed thereon, it is preferred to form a flat at the underside of the head n', and
to form a ledge or lug u at the side of the rim r in position close under the flat of
the head.
The
The roller may present a bearing surface to the chain both forwards and back-
wards, if desired; but, in the arrangement illustrated by Figure 2, each tooth is
shewn with the ears 9 q' projecting backwards beyond the roller and joined across
at their hinder ends by a part w which presents to the chain a solid or rigid sur-
face of the required shape, in case of back-pedalling, or checking the speed.
Both the chain and wheel may be fitted with rollers, if desired, or either of them 5
only may be so fitted.
The formation of each tooth to present a rolling surface at one face, and a solid

page_text: or rigid surface at the other, may be adopted whether the roller is fitted with a
ball bearing of any description or not; and the solid or rigid face may, if pre-
ferred, be formed simply of the edges of the lugs or projections between which
the roller is carried.
"
The invention is, of course, applicable, as will be obvious, to chains and sprocket
wheels, used for various purposes besides those used for cycles.
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 a roller driving chain, the combination of a joint pin passing transversely
through adjacent links, a roller surrounding such pin, recesses in the side faces
of such roller, cones surrounding the axis of the pin, and balls placed within such
recesses and surrounding the cones, substantially as described.
2. In a roller driving chain, the combination of a joint pin passing transversely
through adjacent links, a roller surrounding such pin, recesses in the side faces
of the roller, cones projecting from the inner side faces of the sides of the link
which is the nearer to the roller and formed solid therewith, and balls placed
within such recesses and surrounding the cones, substantially as described.
3. In a chain or sprocket wheel, a tooth formed with ears or projections from the
rim of the wheel, a roller between such ears, recesses in the side faces of the roller,
cones carried by the ears or projections, and balls placed within the recesses and
surrounding the cones, substantially as described.
4. In a chain or sprocket wheel, a tooth formed with ears or projections from the
rim of the wheel, a pin passing through such ears, a roller between such ears and
around the pin, recesses in the side faces of the roller, cones around the axis of
the pin, and balls placed within the recesses and surrounding the cones, substan-
tially as described.
5. In a chain or sprocket wheel, a tooth formed with ears or projections from the
rim of the wheel, a pin passing through such ears, a roller between such ears and
around the pin, recesses in the side faces of the roller, cones around the axis of
the pin one of which has a portion which is screwed through one of the ears or
projections, and balls placed within the recesses and surrounding the cones, sub-
stantially as described.
6. In a chain or sprocket wheel, a tooth formed with ears or projections from the
rim of the wheel, a pin passing through such ears, a roller between such ears and
around the pin, recesses in the side faces of the roller, a cone formed around the
pin and a cone having a portion which is screwed through one of the ears or pro-
jections, balls placed within the recesses and surrounding the cones, and means
by which the cones may be locked when adjusted, substantially as described.
7. In a chain or sprocket wheel, a tooth formed with ears or projections from the
rim of the wheel, a pin passing through such cars, a roller between such ears
and around the pin, recesses in the side faces of the roller, a cone formed around
the pin, a cone having a portion which is screwed through one of the ears or pro-
jections, balls placed within the recesses and surrounding the cones, the said pin
being formed with a portion which passes through the cone which is screwed
through one of the ears or projections and having a nut screwed on the outer end
thereof by means of which the cones may be locked when adjusted, substantially
as described.
8. In a chain or sprocket wheel, teeth provided each with a roller to present
rolling surface to the chain at one face of the tooth, and formed at the opposite
face to present a rigid or solid surface to the chain, substantially as described.
..
1000
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.