Improvements in or relating to Gear Cases for Cycles, and the like.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Gear Cases for Cycles, and the like.
I, ARTHUR WILLIAM WALL, of 3, Merrow Road, Guildford, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as follows; -
This invention relates to improved gear cases for cycles and the like.
A gear-case constructed according to this invention is formed in preferably three
parts, consisting of two discs, which conveniently are partially flanged and a main
body portion, and is preferably made of metal either stamped or cast.
One of the discs, to receive the driving sprocket wheel, is formed with or rigidly
attached to the driving bracket and has a slot or groove formed in any convenient
position on its flange, preferably running obliquely from the outer edge of the
Hange towards the disc body.
The body of the case, which forms one of the chain stays, consists of a box of
convenient shape to contain the driving-gear. At the end of one of the side walls
an opening is left, surrounded partly or entirely by a flange, which may form the
end wall of the case and be adapted to fit on to the flanged disc already described
This flange is furnished with a projection or is otherwise adapted to engage in the
slot or groove or other part of the bracket disc.
The slot and engaging projection or device must be so placed that when fully
engaged the gear case is in the position requisite for it to act as a chain stay. The
opposite end of the other side wall of the case is similarly cut away and this open-
ing is closed by the second disc previously mentioned.
Suitable holes are provided in the discs and the body of the cases for their
respective wheel-spindles. To attach the case, the hind wheel of the bicycle is first
connected to the case, the chain and sprocket wheel being placed in position and
the case opening closed by its disc, the whole being secured by the nut of the wheel
spindle. The opening at the other end of the case is then placed against the fixed
bracket disc, so that the projection is in position to engage with the oblique slot.
The disc and case are then pressed together, and at the same time the case is
partially rotated on the disc until the projection. has completely entered the slot,
or the case and disc have otherwise become completely engaged. This brings the
spindle of the back wheel into proper position with regard to the second chain stay
to which it is then attached in the usual manner.
It is evident that the relative positions of the slot and projection may be reversed:
the projection being placed on the disc and the slot on the case.
The gear case may be made with or without outside bearings. If desired soft
metal or other linings or washers may be employed where the discs engage the
body of the case so as to ensure a close joint.
Such a gear-case as is hereinbefore described possesses the following advan-
tages;
-
It is attached to the frame by a mechanical device which cannot get out of order
or work loose; it is readily attached and detached, absolutely noiseless, light,
strong, and rigid and permits broad ball races to be employed with a comparatively

page_text: narrow tread. The case can be made oil-tight and is particularly well adapted to
contain mechanism for tightening the chain.
Dated this 23rd day of November 1897
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Gear Cases for Cycles, and the like.
'
I, ARTHUR WILLIAM WALL, of 3, Merrow Road, Guildford, in the County of
Surrey, 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 gear cases for cycles and the like, and has for its principal
object to allow of the removal from the machine, of the rear wheel tyre or airtube
without having either to remove the wheel from the machine or to interfere with
the gear case or the driving gear. Other objects and advantages are also attained
by my invention which will be best understood upon reference to the accompany-
ing drawings, wherein,
Figure I is an elevation of the body of the gear case.
Figure II is a plan of part of a rear driving safety bicycle and a sectional plan
of the said case.
Figure III is a side elevation of a safety bicycle showing the position of the
parts when the case is about to be attached to the frame.
Figure IV is a similar view from the other side when the parts are attached.
Figure V is a section showing a modification in which the bottom bracket has
outside bearings.
Like numerals refer to like parts throughout the drawings.
The case is preferably made of metal either sheet or cast; it consists of three
separable parts; the body 2 and the two flanged discs 3 and 4.
The disc 3 may be large enough to receive the driving sprocket wheel 5 when it
is formed with or rigidly attached to the bottom bracket 6, but if other means are
provided for introducing the wheel 5 into the case, as through a slide, the diameter
of the disc 3 may be reduced to little if any more than that of the bracket 6. One
or more oblique grooves 7 are formed in the flange 8 of the disc 3 or its equivalent,
running from the outer edge of the flange towards the body of the disc.
The body 2 which forms one of the chain stays, consists of a box of convenient
shape to contain the driving gear.
At the front end of the inner side wall 9 an
opening 10 is left, surrounded by a flange 10" which may also form the end wall
of the case and is adapted to fit on to the flange 8 of the disc 3. The flange 10
is furnished with one or more internal projections 11 or is otherwise adapted to
engage in the grooves 7 of the disc 3, so that by placing the flange 10" against
the flange 8 with the projections 11 entering the grooves 7, and by then rotating
the case through about a quarter of a circle, with the crank axle as centre, the
flange 10 engages with the flange 8-by a kind of screwing motion and the body 2
of the case becomes firmly attached to the disc 3 or its equivalent and to the
frame of the machine.
The engaging device is so arranged that, when fully engaged, the gear case is
in a position requisite for it to act as a chain stay. At the opposite end the body
of the case is similarly cut away and this opening (12) is preferably provided with
a flange 12, and is closed by the disc 4 previously mentioned. Suitable holes 13,
14 and 15 are provided for the crank spindle 16 to pass freely through the body 2,

page_text: and for the hub end 17 to project freely through the disc 4, and for the rear road
wheel spindle 18 to pass through the body 2, respectively. The flanges of the
openings and discs are provided with apertures 33 to allow of the passage of the
chain.
The disc 4 is passed on to the hub end 17 behind the driven sprocket wheel 19,
which may then be secured in position. To attach the case, the hub end 17 is passed
into the rear end of the body 2, so that the end of the spindle 18 projects through
the hole 15 and the disc 4 is pressed into the flanged opening 12. The case is
fixed to the spindle 18 by a nut (not shown) lying between the outside of the case
and the inside of the end 30 of the stay 29 hereinafter referred to, or by other suit-
able means.
The chain is joined up and inserted in the case, before the said case
is attached. To engage the chain with the wheel 19, the case may be laid on its
side with the wall 9 uppermost and with the chain arranged in a wide curve around
the rear end of the case, so that after the wheel 19 is in position in the case the
chain may be brought into engagement therewith. Or a loop of the chain may be
drawn out through the opening 12 by the side of the back end of the case and
arranged in position on the wheel 19 just before the said wheel is introduced into
the case, the loop of the chain of course going back into the case therewith. The
driving sprocket wheel 5 is next placed in the front end of the case and the chain
engaged therewith. The frame of the bicycle is now raised to about the position
shown in Fig. III and the sprocket wheel 5 threaded on to the end of the crank
spindle 16, so that the gear stands at about 90° to the stay 24. This brings the
flange 10 against the fixed bracket disc 3, so that the projections 11 on the said
flange 10 are in position to engage with the oblique grooves 7. The disc 3 and
case 2 are then pressed together and at the same time the case is partially rotated
on the disc 3 by letting the frame down to its normal position (Fig. IV) when the
projections 11 will have completely entered the grooves 7 and the case has assumed
its permanent position on the bottom bracket 6. The sprocket wheel 5 and
crank 26 are now secured to the spindle 16, preferably by the one cotter 27. The
operation of securing the case to the bottom bracket brings the back wheel
spindle 18 into proper position with regard to the second chain stay 24 and the
saddle stays 28, 29. The stay 24 may be provided with a spring hinged lower
jaw 25 which may be turned down into the position shown in Fig. III to allow the
spindle 18 to take its proper position in the fork-end, when the jaw 25 is sprung
back into line with the stay 24 and the spindle attached to the fork-end in the
usual manner; or an equivalent device may be employed. The saddle stay 29
may be slotted out at the lower end 30 to allow it to take its proper position on the
other end of the spindle 18 outside the case, without springing. The whole is then
secured by screwing the outside nut 20 home on the spindle 18. As the part of
the case around the hole 15 is subjected to a severe strain when the machine is
propelled, I prefer, when the said body is constructed of light material such as
stamped sheet steel, to support it locally by a plate such as 22; and under similar
circumstances the body may be strengthened lengthwise by a tube such as 23 run-
ning from the plate 22 to the opening 10. The plate 22 and tube 23 may be
secured to the body 2 by rivetting, soldering or other suitable means. To further
support the case and hold the parts firmly in position a screw bolt 31 may be passed
through the body 2 of the case and through the front end of the tube 23 into the
bridge piece 32 of the frame.
In order to remove the tyre or airtube from the rear wheel the nuts 20 of the
wheel spindle 18 are loosened, the cotter 27 and the bolt 31 (if any) removed, and
the frame raised from the wheel spindle 16 enough to allow the tyre to be passed
out under the fork end 25. If access to the bottom bracket be desired it is only
necessary to raise the frame to the position shown in Fig. III when the case will
automatically disengage from the frame, remaining attached to the rear wheel
only.
In applying my invention to tandems where both chains are covered. The rear
case and wheel, has a rotary movement as in Fig. III. To do this the flange of

page_text: the disc 3 may be formed on the outer wall of the forward gear case concentric
with the rear crank spindle, to which the disc of the rear case is fitted, by the rotary
movement.
It is evident that the relative positions of the slots and projections may be
reversed; the projections being placed on the disc 3 and the slots on the case.
The gear case may be made with the usual form of bearings as shown in Fig. II
or with outside bearings as shown in Fig. V, when the whole of the front part of
the case is made specially rigid. The two discs when engaged forming an extended
bottom bracket the sprocket wheel 5 being between the bearings. If desired,
soft metal or other linings or washers may be employed where the discs engage the
body of the case so as to ensure a close joint. To allow for the adjustment of the
chain by moving the wheel spindle 18, the hole 15 may take the form of a slot, and
the disc 4 may be made up of two concentric rings provided with a flange or screw
which may either push or screw into each other, opposite rotation of which will
provide the desired longitudinal movement of the hole 14.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I would have it understood
that I am aware that it has already been proposed to secure a gear case to a cycle
by springing or pushing the front end on to a disc secured to the bottom bracket
and I am also aware that it has already been proposed to utilise the body of a gear
case as one of the chain stays of the cycle, and I therefore do not broadly claim
either of these constructions as my invention, but I declare that what I do claim
is:-
1. A gear case for cycles and the like constructed to allow the removal from the
machine of the rear wheel tyre or air-tube, without having either to remove the
wheel from the machine or to interfere with the gear case or driving gear.
2. A gear case for cycles adapted to be secured to or detached from the bottom
bracket by a partial rotary movement relatively thereto.
3. A gear case for cycles or the like, consisting of a body having two openings
and of two discs, one of the said discs being secured to or forming part of the bottom
bracket and having one or more oblique grooves adapted to receive a corresponding
projection or projections in a flange surrounding the corresponding opening in
the body of the case; the other disc being adapted to close the other opening in
the body of the case, all combined, arranged and adapted to operate substantially
as and for the purpose set forth.
4. The combination in a cycle or the like of a gear case such as referred to in the
preceding claims with the arrangement of outside bearings substantially as herein
described with reference to Fig. V of the accompanying drawings.
Dated this 90ml 1
1000
στων κουν
G. DOUGLAS LEECHMAN,
18, Hertford Street, Coventry, 75, Chancery Lane, London, W.C., and
9, Exchange Chambers, New Street, Birmingham,
Patent Agent for the Applicant.