Improvements in Gear Cases for the Gearing Chains and Wheels of Bicycles and Tricycles.
Year: 1894

page_text: Date of Application, 12th Apr., 1894
Complete Specification Left, 14th Jan., 1895-Accepted, 23rd Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in Gear Cases for the Gearing Chains and Wheels of
Bicycles and Tricycles.
I HORACE WALTER DOVER, of 15 Beaconsfield Terrace, Northampton,
Engineer do hereby declare the nature of this invention to be as follows:-
.
1
My invention relates to improvements in gear cases for enclosing and excluding
dust from the gearing chains and wheels of bicycles and tricycles.
The invention relates particularly to the kind of gear case described in the
Specification of former Letters Patent granted to me dated the 4th day of
October 1892, No. 17,686; and it has for its object to enable the gear case to be
more readily adapted to fit the various patterns of machines made by different
makers, so that the gear case can be made of.a stock shape and fitted to any
machine by the purchaser.
.
;
One principal object of the present invention which relates particularly to gear
cases made of papier maché is to avoid cutting away any part of the main body of
the case itself, in order to enable it to make a dust-tight fit to the machine.frame,
the cutting of the case after.it has been enamelled having the defect of exposing the
cut edges of the papier maché to moisture which is readily absorbed and causes the
papier maché to split and blister.
Another object is to enable both the front and rear sides of the case to be made
flat and parallel, instead of the rear side being bulged as heretofore to enable it.
to enclose the forward end of the stay and the bottom bracket which forms the
bearing of the pedal shaft.
Another object is to enable the adjustment of the tension of the chain to be
effected without disturbing the fit of the case upon the rear end of the stay where
it comes through the front side of the case, whether the guide forks (in which the
hub spindle is adjustable for regulating the chain tension) be in line with the stav
or, as in many machines, inclined upwards or downwards at an angle thereto.
Other improvements have for their objects to improve the means of fitting the
case upon the pedal axle and hub so as to ensure a more easy adjustment and a
more dust-tight closure, to improve the fixing of the case to the internal supporting
bracket by which the case is attached to the frame so as to enable it to be more
easily applied, and to provide means whereby the abutting and overlapping edges
of the rear side of the case are held close and prevented from gaping:
'
I will first describe the improvements applied in connection with the pedal axle.
At the front or outer side, instead of the joint being made by a pair of metal
discs placed on the pedal axle (to do which involves dismounting the crank, arm)
said discs receiving between their edges the edges of semicircular openings cut in
the edges of the two parts of the case which, if cut after enamelling, as is often
necessarily the. case, exposes. raw edges to moisture, I cut the semicircular gaps
in the case before enamelling it and rivet or otherwise secure to the case
semi-discs of celluloid or thin metal, capable of being easily cut to fit. close around
the pedal axle, these semi-discs filling the gaps in the case for which they form a
sort of filling piece or bushing and overlapping or abutting edge to edge when the
case is fitted in position: These semi-discs would be corrugated circularly for
strength and elasticity, and to facilitate cutting the semicircular recesses in these
semi-discs to enable them to fit around the axle, the-semi-discs would be made and

page_text: sold complète, that is with no aperture at all so that the centres and concentric
semicircles of various diameters may be pressed or otherwise marked to guide the
fitter in cutting the apertures to suit the diameter of the axle. This is also a great
facility in ensuring axial alignment with the apertures made in the bushing or
filling piece at the opposite or rear side of the case which I will now describe.
This filling piece or bushing is also made of celluloid or thin metal capable of
being easily cut, the same being moulded or stamped of concavo-convex form, so as
to enable it to embrace the front end of the stay and the bottom bracket, whilst the
rear side of the case itself is flat. This bushing or filling piece is made preferably
in one piece and then sawn longitudinally into two halves which are respectively
rivetted or otherwise secured in recesses or apertures cut in the edges of the two
parts of the case to receive them, the said apertures being made before the case is
enamelled so that no cut edges will be exposed. The cut edges of the two parts of
the bushing or filling piece overlap when the case is applied to the machine and
they are made solid or without any recesses to fit around the axle, said recesses
being formed as before described for the front side of the case, by cutting out
semicircular portions for which purpose the centres and concentric semicircles of
various diameters are stamped or moulded in the filling or bushing pieces as guides
to the fitter in cutting said filling or bushing pieces to suit the diameter of the
bottom bracket and ensure axial alignment with the semi-disc bushings or filling
pieces at the front side of the case, as above described.
The fitting of the case to the driving wheel hub and the rear end of the stay, so
as to provide for tensional adjustment of the chain, is effected as follows:-At the
front of the case, where the stay comes through it, the edges of the two parts of
the case are cut away to form an aperture more than large enough for the passage
of the stay (this being done before the case is enamelled) and over the front part of
this aperture is placed a covering plate of metal secured to the case by a screw-bolt,
and by sliding clip fastenings hereafter referred to, said covering plate being
Jongitudinally bulged outwards so as to permit the stay to project beyond the
enter face of the casing, said bulged portion at its rear end forming one half the
socket of a sort of ball and socket joint, the other half of the socket being formed
of an oppositely or inwardly bulged plate hereafter referred to. The ball portion of
the joint is a sort of split collar made preferably of celluloid so as to be capable
of being sprung upon the stay of the frame the collar being of coned form, its
smaller end fitting close around the stay and its larger end being more or less
rounded or approximately spherical so as to fit in the socket above referred to and
maintain a dust-tight joint whilst being free to swivel in order to accommodate
itself to the relative positions of the case and stay which may vary in adjusting the
chain tension. The inwardly bulged plate which forms the other half of the
socket fills the remainder of the oblong aperture in the front or outer side of
the case, and the said plate is fitted to slide in the longitudinal direction of the case,
for the purpose of accommodating itself to the adjustment of the chain tension. In
an aperture in this plate is fixed a collar which is clamped between nuts screwing
on a threaded boss fixed on the hub spindle between the cone bearing of the
driving wheel and the back fork, for the purpose of adjusting the gear case laterally
so as to bring the chain and wheels central within it. This plate being thus fixed
to the driving wheel hub spindle requires to be detachably connected with the case
in order that the latter may be easily mounted on, or dismounted from, the machine
and this easy detachability, the longitudinal sliding adjustment of the plate, and a
<lust tight closure, are provided for by connecting the longitudinal edges of the said
plate to the case by means of sliding clips forming also joint covering strips, such
as are described in my former Patent. Each of said strips has its edges inwardly
recurved towards one another and said inwardly recurved edges fit over and
interlock with outwardly and oppositely recurved flanges formed the one on the
plate and the other rivetted along the edge of the aperture in the case.
There are
two of these joint covering clips in which as guides the plate may slide for purposes
of adjustment, whilst by withdrawing the clips the plate may be wholly detached

page_text: from the case. These clips also engage with similar flanges in continuation of
those above referred to whereby the overlapping portions of the two plates forming
the inner and outer halves of the socket of the ball and socket joint are firmly
connected to each other and to the case whilst permitting the sliding adjustment of
the one plate, as above mentioned.
At the rear side of the case the joint is made between the case and the hub of
the wheel by two plates fitting closely around the hub, as in my former Patent,
but these plates are free to slide only in the longitudinal direction of the case and
not also towards or away from one another, as in the former case. The plates slide
between the face of the case and cover plates rivetted thereto and they are
prevented from receding from one another by guide flanges formed on their edges
abutting against the edges of the cover plates. These adjustable plates are made
of very thin metal or celluloid, so that semicircular recesses may be easily cut in
them to fit the hub, and to enable these to be truly cut to the proper size and in
proper position at the time of fitting to the machine, a centre mark and concentric
semicircles of various diameters are stamped or moulded in the portion to be ent
away, to guide the fitter in cutting them to suit the diameter of the wheel hub.
The preferred way to make these plates is to stamp or mould the two plates in one,
so as to cup them, and also form a longitudinal crease or corrugation near each end
along the line of division, and then to cut them in two so that the guide flanges
above mentioned are formed by the sides of the creases or corrugations, the middle
portion of the plate not being apertured but left solid and marked as above
mentioned, to guide the fitter in cutting to fit the hub.
The screw-stud which as before mentioned secures the outer half of the socket
of the hall and socket joint detachably in position on the case, traverses the case
from side to side and is provided with a fixed shoulder which abuts against the
inside of the opposite wall of the case, the threaded end of the screw traversing an
eyeletted hole therein and screwing into a hole tapped in an arm at the outside of
the case this arm being rivetted to the opposite half of the case to that through which
the screw passes and lying across the joint between the two halves, so that by
means of this same screw the overlapping edges of the two parts of the case are
pressed into close contact and bulging or gaping of the joint prevented. This
joint, which is at the rear side of the case, is made, as in my former Patent, by a
metal lip rivetted to the one-half of the case overlapping the edge of the other half
of the case, whilst the joint at the front or outer side of the case is also made, as in
my former Patent, by a longitudinally sliding joint covering clip having inwardly
recurved flanges which interlock with outwardly and oppositely recurved flanges
rivetted along the edges to be connected, whilst similar joint covering clips of
U-form are slid on and embrace the ends of the case.
The internal bracket by which the case is supported is secured, as before, by a
strap and nuts to the rear leg or stay of the frame, but the case instead of being
connected to it by a nib projecting between the abutting edges of the two parts of
the case is connected by a screw bolt passing completely across the case from side
to side, said bolt abutting against the outer or front face of the case and screwing
into a threaded socket rivetted to the rear face of the case, the shank of the bolt
lying in a groove in the internal bracket, the bolt when tightened up clamping the
two sides of the case firmly against the opposite sides of the bracket.
The bracket is grooved at both sides so that the screw bolt may pass it on either
side the position of the bracket depending on the diameter of the chain wheel and
the shape of the stay whilst the position of the screw is determined by the hole and
nut to receive it.
Lastly to prevent the chain rattling against the case I provide instead of the
spring pad described in my former Patent a pad formed of a leather tube held in
position in the case by a flat spring which as well as the tubular pad within which
it is placed is bent to a U shape to conform to the case and is held in place therein
by a screw and nut, the pad by reason of its tubular form acting as a soft cushion
for the chain passing between the pad at the opposite sides of the case.

page_text: All the above described improvements are also equally applicable to a gear
case made of sheet metal which is itself difficult to cut to fit the various patterns
of machines.
Dated this 10th day of A 1001
H. W. DOVER,
By A. M. & Wm. Clark,
53, Chaucery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Gear Cases for the Gearing Chains and Wheels of
Bicycles and Tricycles.
I, HORACE WALTER DOVER, of 15, Beaconsfield Terrace, Northampton,
Engineer, do hereby declare the nature of this invention, and in what manner
the saine is to be performed, to be particularly described and ascertained in and
by the following statement :-
My invention relates to improvements in gear cases for bicycles and tricycles.
The invention relates particularly to the kind of gear case described in the
Specification of former Letters Patent granted to me dated the 4th day of October
1892, No. 17,686; and it has for its object to enable the gear case to be more
readily adapted to fit machines of various patterns.
One principal object of the present invention, which relates particularly to gear
cases made of papier-maché, is to avoid cutting away any part of the main body of
the case itself, in order to make a dust-tight fit to the machine frame, the cutting
of the case after it has been enamelled having the defect of exposing the papier-
maché which by absorbing moisture becomes split and blistered.
Another object is to enable both the front and rear sides of the case to be made
flat and parallel, instead of the rear side being bulged as heretofore, to enable it to
enclose the forward end of the stay and the bottom bracket which forms the
bearing of the crank shaft.
Another object is to avoid disturbing the fit of the case (upon the rear end of
the stay where it comes through the front side of the case) when the tension of the
chain adjusted, whether the guide forks (in which the hub spindle is adjustable
for regulating the chain tension) be in line with the stay or inclined upwards or
downwards at an angle thereto.
Other improvements have for their objects to improve the means of fitting the
case upon the crank shaft and hub so as to ensure a more easy adjustment and a
more dust-tight closure, to improve the fixing of the case to the internal supporting
bracket by which the case is attached to the frame so as to enable it to be more
easily applied, and to provide means of preventing gaping of the abutting and
overlapping edges of the rear side of the case.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein
Figure is an outside face elevation, partly in section, Figure 2 is a cross section
of same, at the fixing bracket.
Figure 3 is a horizontal section, at the joint between the two parts of the case
and shewing the case applied to the machine.
Figure 4 is an inside face elevation of the case inverted and partly in section to
shew mcdifications of the leather pad.
The same letters of reference denote like parts in all the figures.
A is the top half and B the bottom half of the gear case. Cis the crank shaft,
D the driving wheel hub, and E the stay of the frame.
I will first describe the improvements applied in connection with the crank
shaft C.
At the front or outer side of the gear case, instead of the joint being made by a

page_text: pair of complete discs of metal fitting on the crank shaft and receiving between
them the edges of semi-circular gaps in the two parts A, B, of the case (the cutting
of which, after enamelling, would expose raw edges to moisture) semi-circular
gaps ff, are formed before the case is enamelled and these gaps are filled by semi-
discs F, F, of celluloid rivetted to the two parts A, B, of the case and either
abutting edge to edge or overlapping. These semi-discs F, F, would be corrugated
circularly for strength and elasticity, and they may be easily cut out to fit the
crank shaft, to facilitate which operation they would be made blank (that is
without any recess at all) and have centre marks and concentric semicircles f*
of various diameters pressed or otherwise marked in them as guides in cutting
them, to fit the shaft, these guide marks also facilitating axial alignment of the
apertures at the two sides of the case.
The filling piece or bushing at the rear side of the case is also made of celluloid
moulded of concavo-convex form so as to enable it to embrace the front end of the
stay E and the bottom bracket G whilst the rear side of the case A, B, itself is flat.
This filling piece is moulded in one piece and then sawn longitudinally into
halves H, H, which are respectively rivetted or otherwise secured to the two
parts A, B, so as to close the recesses h made therein before the case is enamelled.
The two parts H, H, of the filling piece overlap when the case is applied to the
machine and they are made blank (ie. without recesses) and have centre marks h¹
and concentric semicircles of various diameters formed in them as guides to the
fitter in cutting them to fit the bottom bracket and ensure axial alignment of the
apertures at the two sides of the case, as above described.
-
The fitting of the case to the driving wheel hub D and the rear end of the stay E
so as to provide for tensional adjustment of the chain, is effected as follows:-
At the front side of the case, where the stay comes through it, the two parts of the
case are cut away more than enough for the stay and over the forward part of the
oblong aperture thus formed is placed a covering plate I of metal secured to
the case by a screw bolt R and by sliding clip fastenings J, J, hereafter referred
to, said covering plate. I being longitudinally bulged outwards, as shewn, so as to
permit the stay E to project beyond the outer face of the casing. The said bulged
portion forms at its rear end 1 one half of the socket of a sort of ball and socket
joint, the other half of the socket being formed of an oppositely or inwardly bulged
plate K which covers the remainder of the oblong aperture in the front side of the
casing, the adjacent ends of the two plates I, K, overlapping to form the socket."
The ball portion L of the joint is a sort of longitudinally-split collar made of
celluloid capable of being sprung upon the stay E, the collar being of coned form,
its smaller end fitting close around the stay E and its larger end being more or
less rounded or approximately spherical so as to fit in the socket formed by the
oppositely bulged plates I, K. This ball and socket enables a dust-tight joint to
be maintained whilst the ball portion is free to swivel in order to accommodate itself
to the relative positions of the case and stay which may vary in adjusting the chain
tension. In an aperture in the plate K is fixed a collar M which is clamped
between nuts m, m³, screwing on a threaded boss m² fixed on the hub spindle D
between the cone bearing of the driving wheel and the back fork N for the purpose
of adjusting the gear case laterally so as to bring the chain O and chain wheel P
central within it. This plate K being thus fixed to the driving wheel hub spindle
requires to be detachably connected with the gear case and it also requires to be
adjustable in the longitudinal direction of the case in order to accommodate itself
to the adjustment of the chain tension. These requirements are provided for by
connecting the longitudinal edges of the plate K to the case by means of sliding
clips J, J, which also form joint covering strips, such as are described in my former
Patent. Each of said clips has its edges inwardly recurved towards one another
and said inwardly recurved edges fit over and interlock with outwardly and
oppositely recurved flanges formed the one on the plate K and the other rivetted
along the edge of the part A or B of the case. In these two joint covering-clips as
guides the plate K may slide for purposes of adjustment whilst by withdrawing the

page_text: clips the plate is wholly detached from the case. These clips also engage with
similar Hanges in continuation of those fixed to the case and formed on the
plate I, whereby the overlapping portions of the two plates I, K, are firmly
connected to each other and to the case.
At the rear side of the case the joint is made between the case and the hub by
two plates Q, Q, fitting closely around the hub. These plates Q are not movable
towards or away from one another, as in my former Patent, but are free to slide
only in the longitudinal direction of the case. They slide between the case and
cover plates Q, Q, rivetted thereto and their abutting edges are held close
together by guide flanges engaging against the edges of the cover plates Q
These adjustable plates are made of very thin metal or celluloid and are made
blank, or without recesses, a centre mark and concentric semicircles of various
diameters being stamped or moulded in them as guides in cutting them to fit the
hub. The preferred way to make these plates is to stamp or mould the two plates
in one so as to cup them as required, and also form a longitudinal crease or corra-
gation near each end along the intended line of division, and then to cut them
longitudinally in halves so that the guide flanges y will be formed by the sides of
the crease or corrugation.
P
The screw stud R traverses the lower part of the case from side to side and has
a fixed shoulder which abuts against the inside of the case, the threaded end of
the screw traversing an eyeletted hole in the case and screwing into a hole tapped
in an arm rivetted to the outside of the upper half of the case, so that by means
of this same screw the overlapping edges of the two parts A, B, of the case are
pressed into close contact and gaping of the joint at the rear side of the case
prevented. This joint is made, as in my former Patent, by a metal lips rivetted
to the upper half A. overlapping the edge of the lower half B of the case.
joint at the front side of the case is made, also as in my former Patent, by a longi-
tudinally sliding joint covering clip T having inwardly recurved flanges which
interlock with outwardly and oppositely recurved flanges t, rivetted along the
edges of the parts A, B, whilst similar joint covering clips U, U, of U-form
embrace the ends of the case and engage flanges thereon.
The
The internal bracket V by which the case is supported, is secured as before by a
strap and nuts o' to the rear leg or stay E of the frame, but the case is connected
to it by a screw bolt W passing completely across the case from side to side, said
bolt abutting against the outer or front face of the case and screwing into a
threaded socket w rivetted to the rear face of the case, the bolt passing through an
-oblong hole in the bracket and when tightened up clamping the two sides of the
case firmly against the opposite sides of the bracket V.
Lastly, to prevent the chain rattling against the case, I provide pads each
formed of a flattened tube X of leather bent to a U shape and held in position in
the gear case (which is moulded with a recess to receive it) by a U-shaped spring c
within it secured to the case by a screw and nut, the pad by reason of its yielding
-character and tubular form acting as a soft cushion for the chain passing between
the two limbs of the U-shaped pad.
Instead of the pad X being formed by a complete tube of leather, as above
mentioned, it may be formed by a strip of leather bent to a half-tubular form as in
Figure 4, its edges being fixed in the flanged edges of a U-shaped strip of sheet
metal.
All the above described improvements are also equally applicable to a gear case
made of sheet metal which is itself difficult to cut to fit the various patterns of
machines.
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. The herein described improvements severally and in combination, substantially
-as specified.

page_text: 2. Forming the outer face of the case at the front end with an aperture larger
than required for the crank axle closed by semi-discs of celluloid rivetted to the
two parts of the case, as specified.
3. Providing at the inner face of the case at the front end au aperture larger
than required to give room for the stay and bottom bracket, and closing the same
by filling pieces of celluloid rivetted to the two parts of the case and of bulged
form as described, so as to embrace within them the stay and bottom bracket whilst
allowing the case itself to be made flat, as described.
4. Providing the case with a ball and socket joint constructed and applied as
described to connect the case to the stay passing through the outer face of the case
and permit of variation of the position of the case relatively to the stay consequent
on adjustment of the chain tension, as described.
5. Constructing the ball and socket, the former of a split collar of celluloid
shaped as described and the latter of oppositely bulged metal plates connected to
the case by sliding clips embracing flanges on the plates and case and permitting
the necessary adjustment and easy removal of the plates, as specified.
6. Providing at the inner face of the case at the rear end, an aperture larger
than required for the passage of the hub and closing the same by filling pieces of
celluloid adapted to slide longitudinally within cover plates rivetted to the outside
of the case, as described.
7. Securing the case to the internal supporting bracket mounted on the stay by
a through bolt traversing the one half of the case from side to side, passing through
the bracket, and screwing into a nut fixed to the rear side of the case substantially
as specified.
8. Preventing gaping of joint at rear side of case by a shouldered bolt bearing
against inside of one half of case and screwing into an arm fixed to the other half
of the case and lying across the joint between the two halves, substantially as
specified.
9. Forming the celluloid semi-discs or filling pieces for the various apertures in
the case, with centre marks and concentric semicircles of various diameters, as
guides in cutting to fit the machine, as specified.
10. As an improvement in gear cases, generally, the herein described tubular or
semi-tubular U-shaped leather pads for preventing rattling of the chain, as
described.
Dated this 14th day of January 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.