Year: 1889

page_text: I, WILLIAM BLAKELY, of Dene House, Bournemouth, in the County of Hants,
Estate Agent, 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 :-
My Invention relates particularly to pitch chain driving gear especially suitable
for bicycles and tricycles but applicable also to all classes of machinery; and it has
for its object to combine great lightness with durability and freedom from liability of
breakage and to lessen vibration."
The Invention consists first of a pitch chain wheel formed of pairs of discs radially
corrugated and clamped together as hereinafter described so as to form a wheel having
a cupped periphery, and of a pitch chain formed with balls made in halves secured
together with the links between them and preferably of oval form adapted to engage
in said cupped periphery as hereafter described; secondly of a pitch chain wheel made
of a pair of dished dises clamped together face to face, the rims of which discs are
notched to form the sprockets, and thirdly of a band to be used either as a substitute
for the ordinary pitch chain or for driving purposes generally; also forms of wheel
particularly adapted to be used with this band.
Reference is to be had to the accompanying drawings forming part of this specifi-
cation wherein figure 1 is a face view of the wheel and pitch chain, the nearest disc
of the wheel being removed. Figure 2 is an edge view of the wheel separately, and
figure 3 shews a portion of the chain to be used with the wheel shewn in figures 1
and 2. Figures 4 and 5 shew face and edge views of a wheel in which the discs are
not corrugated, while figures ti and 7 shew the dished form. Figures 8, 9, and 10,
shew the band of the improved construction above referred to running on a wheel
adapted to same. Figures 11 and 12 shew this band applied to a wheel which has a
ronghened surface instead of sprockets which is admissible with a band of this con-
struction. Figures 13 and 14 shew a sprocket wheel of peculiar construction
hereinafter referred to.
The wheel shewn in figures 1 and 2 is constructed of two discs a a of thin sheet
1797

page_text: steel or other suitable metal stamped up with equidistant radial corrugations 6 and
clamped together or to opposite sides of an intervening disc c of lesser diameter so tha
the concavities of the corrugations of the two dises a are opposite each other and form
a series of cups around the rim of the wheel adapted, to receive the balls d of the
pitch chain. The discs a may have holes punched in them, for the sake of lightness,
and they are secured to the disc c which is of hard wood by rivets, screws, or other-
wise. Or the discs a may be rivetted directly together without the intervention of a
disc, provided that their marginal portions are sufficiently divergent to admit the flat
links of the pitch chain between them. The pitch chain is made of metal balls d
connected by intermediate flat links e pin-jointed to the balls d. as shewn.
In figures 4 and 5, the discs are flat and are also kept apart by an intermediate disc
or distance piece c and their rims. or edges are notched to form the sprockets. The
discs and distance pieces are rivetted or bolted together.
In figures 6 and 7, the dished discs a are bolted together face to face without any
intermediate disc and their rims or edges are notched to forni the sprockets for the
chain. These sprockets are preferably of a A form, so that the chain will readily
engage and disengage itself. With a wheel of this construction an ordinary pitch chain
would be employed. If desired, to prevent vibration, the hollow space between the
discs may be filled with wood or other material.
The band shewn in figures 8, 9, and.10, may be used for driving machinery generally.
It is composed of a flat strip of steel a covered on one or both sides with a layer or
layers of leather b or equivalent material of a width corresponding to the width of the
steel band. The leather layer or layers are rivetted cemented or otherwise secured to
the metal band, the surface or surfaces of which may be roughened to cause the leather
to adhere more firmly. If this band is to be used with a sprocket wheel, the edges of
both the steel band and the leather coverings are notched to engage the sprockets
which in this case may be pins c projecting from the periphery of the wheel d and
either fixed therein as shown or fitted loosely in sockets and provided with springs by
which they are protruded from the wheel. In the drawing the wheel is represented
as being made solid, but it is obvious that it may be built up as in figures 4 and 5. A
band of this character is lighter than the ordinary pitch chain and the fact that it has
a foundation of steel enables it to be used anywhere where great resistance to tensile
strains is required.
In figures 11 and 12 a similar band is used but instead of the sprockets I
roughen the surface of the periphery of the wheel either by inserting needle points
therein, as shewn, or otherwise, so as to provide a surface that will grip the leather
faced band and avoid slip. In this case, the band of course is not notched. The
wheel is cambered, as shown, to keep the band running "centrally. The wheel
shewn in figures 8, 9, and 10, may be roughened as in figures 11 and 12, the
roughening of the wheel tending to relieve the sprockets from undue strain.
In figures 13 and 14, the sprockets consist of gib-headed spring arms screwed
radially to the face of the wheel, their gib ends embracing the edge of the wheel
and standing up from the periphery and forming sprockets. Instead of spring arms,
however, the arms may be pivoted to the face of the wheel and provided with springs
which tend to press them inwards, but enable them to yield to any side strain.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, 1 declare that what 1
'claim is :-
1st. The herein described pitch-chain driving gear, consisting of chain wheels
constructed of pairs of discs of sheet steel or other suitable metal corrugated and
clamped together as described, in combination with a pitch chain having balls or
enlarged links adapted to engage in the cupped peripheries of the said chain wheels,
as described.
2nd. A sprocket wheel for pitch chain gear consisting of a pair of dished discs
secured together face to face and having their edges or rins, notched to form
sprockets, as specified.

page_text: 3rd. A sprocket wheel for pitch chain gear consisting of a pair of flat discs notched
to form sprockets and kept apart by a distance piece and the whole bolted or rivetted
together, as specified.
4th. A driving band for machinery, composed of a flat strip of spring steel or other
metal covered on one or both sides with a layer or layers of leather or equivalent
material the leather being secured to the metal strip by cementing or otherwise, as
specified.
5th. A sprocket wheel in which the sprockets consist of gib-headed spring arms
secured radially to the face of the wheel, as specified.