Improvements in or relating to Chain Driving Gear.
Year: 1897

page_text: Date of Application, 11th Mar., 1897-Accepted, 15th May, 1897
COMPLETE SPECIFICATION.
Improvements in or relating to Chain Driving Gear.
I, WILLIAM GEORGE BIRKINSHAW, of Old Croft House, Quarndon, near
Derby, in the County of Derby, Merchant. do hereby declare the nature of
this invention aud 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 chain driving mechanism suitable for cycles, and for
other purposes, and will be best understood by reference to the accompanying
drawings, in which
Figure 1 is a side view showing a pulley and chain constructed according to the
invention.
Figure 2 is a face view of that side of the chain which hears upou the
wheel.
Figure 3 is a side view of part of a wheel and chain of somewhat modified
construction.
Figures 4 and 5, represent in plan and side elevation respectively, a chain upon
the pneumatic principle.
Like letters indicate like parts throughout the drawings.
A is the chain wheel not of ordinary construction but having its periphery
formed in a series of flats A' of such a length that the point A' at the intersection
of each two flats would correspond with the position which in an ordinary chain
wheel would be occupied by a tooth so that the pitch of the points A³ would
correspond with the pitch of the chain. Upon the outside of the wheel is placed a
holding surface A' of suitable material, conveniently rubber which may be
vulcanized solutioned, rivetted or otherwise secured to the wheel A. This holding
surface is the one upon which the chain operates and it may be roughened or varied
in form to accommodate the shape of the chain links. In the present example it
is provided with a series of shallow hollows A' of shape and size approximately
corresponding with the links of the chain presently to be described. The chain is
formed of a series of hollow links B which may be made in any suitable manner,
conveniently by stamping or pressing them out of thin metal or by casting them.
Each link B has hollow cylindrical ends B¹ through which pins C¹ pass for the
purpose of connecting the links B with the pairs of intermediate side plates C.
C is a space between the side plates C, which when the teeth to be presently
described, are employed, may receive thein. These teeth are intended to serve
merely as a device for preventing any considerable slip of the chain; if desired
they may be dispensed with for it is not intended that the chain should normally
act on them.
Each hollow link B has a filling or bearing surface B³ of rubber or other
suitable material which may be secured in the link in any desired munner.
For
instance the side walls of the link may be pressed inwardly towards each other
and the rubber sprung in or the back of the plate may be removed or partly
removed and the block may be provided with a flange at the back so as to hold it
in position. Or again the block may be rivetted as shown at B3 Figure 2, or it
may be solutioned or vulcanised. As shown in Figure 1 the link blocks B' are
of approximately similar shape to the hollows A upon the periphery of the wheel
and these being good holding surfaces the wheel and chain can be worked without
the usual teeth; it being intended that the blocks should each make contact in the
hollows A along a line parallel with the axis of rotation of the wheel; when so
desired the teeth D, Figure 1 may be used, being either formned solid with the
wheel, or they may be provided with shanks D' passing through the wheel rim
Pyt

page_text: and may then serve the additional purpose of securing the holding face A' to the
wheel. Generally speaking, the teeth D are not required, as a sufficient hɔll i‹
secured with the arrangement previously described.
Although I prefer to cover the periphery of the wheel with the holding
surface A³, I wish it to be understood that I may dispense with that holding surface
making the periphery of the wheel itself correspond with the holling faces of the
chain.
In Figure 3 is shown a modification in which the rounded face B' of the chain
and hollow face A' of the wheel are reversed, the link being hollowel and the
wheel raised. The chain in this case is shown with the side plates C dividel
and jointed at C³, the pitch of the chain being thus increased.
When it is desired that the pads B of the chain should be inflate this may be
accomplished by employing the tube E running beside or through the liuks aul
having connecting branches E' one to each pal B³. An inflating valve Eª mɩy be
carried by one of the links or it may be connected to the tube E so that one
inflation may serve for the whole of the pads. The tubing may be rubber protected
by silk covered wire or flexible metallic tubing or other suitable tubing. The
wheel may be similarly arranged so that the whole or a portion of the holling
surfares A may be inflated or only the wheel or the chain may be inflated.
Various modifications may be made in the details of this apparatus without
departure from the invention; for instance the in liarubber on the links may
extend right round them being sprung into or moulded into place; the link and
the rubber being preferably so formed as to mutually engage each other, or they
may be other ise secured together.
Some or all of the links may consist of short links or sections et frin a
flattened or other tube and so forined that tae links of the chain may be fray to
adjust themselves otherwise to a slight extent relatively to each other during
working; the pins or rivets by which the several links of the chain are eng ɩge i
may be provided with rollers, and pins or rivets carrying rollers may be interposed
between the side bars of certain of the links, so as to be presentel towards the
teeth when the chain is at work.
The contact surfaces of the chain and chain wheel can be of various forms suited
to mutually engage and may consist or be faced with for instance papier mache
or wood.
Wood links may be employed in the chain.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is ;-
1. A chain wheel for chain driving gear constructed and operating substantially
as described and illustrated in the accompanying drawings.
2. A driving chain constructed and operating substantially as described and
illustrated in the accompanying drawings.
3. The combination of a driving chain and wheel substantially as described and
illustrated in the accompanying drawings.
4. In a driving chain the employment of holding blocks or pads such as B
substantially as and for the purpose described or illustrated in the accompanying
drawings.
5. A driving chain having inflated holding blocks or pads substantially as
described.
6. The chain wheel having an inflated driving surface substantially as described.
1009
BOULT & WADE,
Agents for the Applicant.