Improvements in Chain Gearing.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Chain Gearing.
I, THOMAS HEWETT, of 8, Ashbourne Grove, East Dulwich, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:
This invention has reference to improvements in chain gearing, whereby con-
siderable frictional contact of the working parts is avoided, thus enabling the
driving power to be applied to better advantage.
In carrying out my invention I provide the rim of the chain wheel, or wheels,
with rotatable discs, or rollers, suitably arranged so as to engage with corre-
sponding rotatable discs, or rollers, on the chain, thereby forming a rolling contact
between the wheel, or wheels, and the chain.
According to one form of my invention provide the rim of the chain wheel
with two sets of rollers, one set or series, being outside the other. In the outer
series of rollers each roller contacts with one roller on the chain, to transmit the
driving power. In the inner series two rollers on the wheel contact with each
roller on the chain, so as to form a rolling path or bed for the chain.
Or the inner series of rollers may have only one roller on the wheel to each
roller on the chain, and the outer series of rollers on the wheel may present
two rollers to each roller on the chain, one in front of and the other behind said
chain roller, the one roller on the wheel serving to transmit the driving power, the
other being an idle roller to take up any slackness in the chain.
Or both inner and outer series of rollers may be double, engaging with either
double or single rollers on the chain.
Suitable means for adjustment are provided so that slackness of the chain or
wear of the parts may be taken up by altering the positions of the rollers on the
wheel, as by the provision of extra holes or supports for their axes, or equivalent
means.
The rollers on the chain wheel may be carried by side flanges or by an annulus
carried by the wheel, the flanges serving to keep the chain in its place on the
wheel. Or in some cases I may dispense with the retaining flanges on the wheel,
and provide the chain with flanged rollers.
In a modified form of my invention I dispense with the inner set or series of
rollers on the chain wheel, the rim serving as a path or bed for the chain, said
rim being covered with leather or other suitable material to render the action
of the chain more or less noiseless.
In an improved form of chain, to be used with a chain wheel, having rollers in
place of spur teeth of the character already mentioned, and designed so that the
parts on the wheel shall engage with alternate sets of rollers on the chain the rolls
are in twin or double sets and in use only the rearward rolls operate to pull or
are operated to be pulled, by the rolls of the wheel the forward rolls serving as
idle rolls to prevent backlash and ease the engagement of the contacting parts
especially when such are being driven at a high rate of speed. In this chain

page_text: the pitch length of the chain is made up of a single and a double link. For
instance if the chain is of one inch pitch, it may be made up of single links inch
in length and double links inch in length, or single links of inch and double
links of inch in length may be used.
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Improvements in Chain Gearing.
I, THOMAS HEWETT, late of 8, Ashbourne Grove, East Dulwich, in the County 1
of Surrey, but now of 6, Jeffreys Square, in the City of London, 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 has reference to improvements in chain gearing, whereby con- 1
siderable frictional contact of the working parts is avoided, thus enabling the
driving power to be applied to better advantage.
In carrying out my invention I provide the rim of the chain wheel, or wheels,
with rotatable discs, or rollers, suitably arranged so as to engage with corre-
sponding rotatable discs, or rollers, on the chain, thereby forming a rolling 2
contact between the wheel, or wheels, and the chain.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a sectional side view of one half of a wheel, in accordance with one
form of this invention, with a piece of chain engaging therewith.
Fig. 2 is a sectional view of the same.
Fig. 3 is a similar view to Fig. 1 of a modification, and
Fig. 4 is a sectional plan view of the same.
Figs. 5 and 6 are sectional side views showing parts of wheels, with portions
of chains engaging therewith, according to alternative forms of this invention.
Fig. 7 shows a cross sectional view of a modified form of chain having flanged
rollers, with the rim of the wheel modified to suit.
Fig. S is a part side view of the same.
Fig. 9 is a cross sectional view of a further modification of the chain wheel
in which the inner set or series of rollers is dispensed with.
Fig. 10 is a plan view of a portion of chain.
Fig. 11 is a plan view of an improved form of chain in which the rolls are in
twin or double sets.
Fig. 12 is a side view showing the same chain engaging the rollers of a wheel.
Fig. 13 shows a modified form of the twin roller chain shown in Fig. 11.
According to one form of my present invention, shown by Figs. 1 and 2, I
provide the rim of the chain wheel with two sets of rollers, one set or series a
being outside the other set or series b. In the outer series of rollers a, each roller
contacts with one roller c on the chain to transmit the driving power. In the
inner series b two rollers on the wheel contact with each roller c on the chain, so
as to form a rolling path or bed for the chain.
Or, as shown in Figs. 3 and 4, the inner series of rollers 6 may have only one
roller on the wheel to each roller c on the chain, and the outer series of rollers a
on the wheel may present two rollers to each roller c on the chain, one in front

page_text: and the other behind said chain roller, the one roller on the wheel serving to
transmit the driving power, the other being an idle roller to take up any slack-
ness in the chain.
Or both inner and outer series of rollers may be double, as shown in
Figs. 5 and 6, engaging with either double rollers, (see Fig. 5) or single rollers
(see Fig. 6) on the chain.
Suitable means for adjustment are provided, so that slackness of the chain, or
wear of the parts, may be taken up by altering the positions of the rollers on the
wheel, as by the provision of extra holes e¹, Fig. 3, or supports for their axes.
One of the rolls b is omitted from Fig. 3 the better to admit of the extra hole being
seen.
The rollers on the chain wheel may be carried by side flanges, d, d, or by an
annulus carried by the wheel, the flanges serving to keep the chain in its place
on the wheel, as described and shown in the specification of Letters Patent granted
to me, numbered 11882 and dated 1st June 1896.
Or, in some cases, I may dispense with the retaining flanges on the wheel,
c¹ are the
and provide the chain with flanged rollers as shown in Figs. 7 and 8.
flanges of the chain rollers c, said flanges serving to keep the chain in place on
the rim f of the wheel.
In a modified form of my invention I dispense with the inner set or series of
rollers on the chain wheel, the rim f, see Fig. 9, serving as a path or bed for the
chain, said rim being covered in some cases but not always with leather, green
or raw hide or other suitable material g to render the action of the chain more
or less noiseless.
In Fig. 10 is shown a plan view of a portion of chain, for use with chain wheels
described herein, and substantially as described and shown in the specification
of Letters Patent granted to me No. 15731 dated 16th July A.D. 1896. c are the
rollers, the connecting links, and the pins or rivets. As shown at A I some-
times form the washers c countersunk on their outer faces to receive the rivetted
outer ends of the pins c.
In an improved form of chain, to be used with a chain wheel, having rollers
in place of spur teeth of the character already mentioned, and designed so that
the parts on the wheel shall engage with alternate sets of rollers on the chain,
the rolls c are in twin or double sets, as shown in Figs. 5, 11 and 12, and in use
only the rearward rolls operate to pull, or are operated to be pulled by, the rolls
of the wheel, the forward rolls serving as idle rolls to prevent back lash and ease
the engagement of the contacting parts, especially when such are being driven
at a high rate of speed. In this chain the pitch length of the chain is made up
of a single and a double link. For instance, if the chain is of one inch pitch, it
may be made up of single links inch in length and double links inch in
length, or single links of inch and double links of 3 inch in length may be used.
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 chain gearing the use of a chain having discs, or rollers, thereon adapted
to form the rolling contact surfaces to engage and drive, or be driven by, other
rotatable discs or rollers, mounted on the rims of the wheel in place of teeth, whilst
other rollers arranged in a circle of lesser diameter serve as a bed on which the
discs, or rollers, of the chain may rest with minimised friction, all substantially
as and for the purpose set forth and shown by the drawings.
2. In a chain gearing wheel the use of rims having mounted on their inner
faces rollers, in series, adapted to act as teeth to engage parts of a chain, in
combination with other rollers in series in a circle of smaller diameter than the
circle of roller teeth, so as to form a bed, or support, on which the parts of the
chain may rest, all substantially as and for the purpose set forth.

page_text: 3. The construction and use of a chain with rolls arranged as shown, in twin,
or double, sets so that only the rearward roll of each pair, at each side of a link,
operates to pull, or is operated to be pulled by, the cooperating rolls of a wheel,
the corresponding forward roll of each pair serving as an idle roll to prevent back
lash and obtain ease in working, substantially as described and shown by the
drawings with reference to Figures 5, 11, 12 and 13.
4. The several arrangements or combinations of parts of chains and chain
wheels as shewn and described with reference to Figures 1, 2, 3, 4, 5, 6, 7, 8,
12 and 13.
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5. The construction of chain wheel of the kind shown, but without the inner
circle of rollers, or roller bed and in place thereof using the periphery of the
wheel between the flanges as the bed, either covered with leather, or equivaleat
sound absorbing material, or bare, as set forth with reference to Figure 9 of
the 'drawings:
Dated the 16th day of December 1897.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.