Improvements in Gear Cases for Cycles.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Gear Cases for Cycles.
I, ALEXANDER MELVILLE CLARK of the Firm of A. M. & Wm. Clark of 53,
Chancery Lane in the County of Middlesex, Fellow of the Chartered Institute of
Patent Agents, do hereby declare the nature of this Invention (a communication
to me by Peter Schlesinger of Offenbach-on-Main, Germany, Manufacturer;)
to be as follows:-
This Invention has for object to provide a lighter, cheaper, and more durable
form of cycle gear case, and it consists in the use of a peculiarly formed sheet
metal peripheral frame in combination with side plates of celluloid, sheet metal,
or the like. The improvement consists in the mode of connecting the edges of
the flat sides of the case with the peripheral frame; in the manner in which the
case is divided into two halves; and in the mode of attachment of the case.
The joint between the two halves of the case follows an approximately Z-shaped
line, being in the plane of the crank and driving wheel axles at the middle part
and then extending upwards from the driving wheel axle and downwards from the
crank axle. This form of gear case has the advantage of being easily fitted,
opened, and inspected.
The upper half is attached to the machine frame in any suitable manner, whilst
the lower half is attached to the upper half by means of a pair of slotted plates
and clamping screws so that the upper part having been fixed it is only necessary
to slide the lower part into position and to tighten up the screws.
Heretofore the gear case has been generally fixed to the stay which extends
transversely through the gear case, but in the present case the peripheral frame
of the case is attached to one of the back legs of the machine frame whereby a
lighter and more secure attachment is effected and the fitting and removal of the
case is facilitated. A simple means of attachment consists of a sheet metal angle
piece on the frame of the case and a clip embracing the back leg of the machine
frame, the two being connected by a screw and nuts, the angle piece being slotted
to permit of adjustment of the case.
The edges of the peripheral frame of the gear case are formed with grooved
flanges to receive the edges of the side plates and for this purpose the flanges
are bent up into the plane of the side plates, the bent-up flanges being formed
in a peculiar way, and the edges of the side plates being if desired formed to
correspond. The flanges of the frame are formed with a continuous or interrupted
groove in which the edges of the side plates are inserted and clipped, the grooved
flanges also serving to stiffen the frame of the gear case. They may be formed of
different shapes and in different ways by bending, or by punching or stamping, and
bending certain parts.
The sheet metal peripheral frame may either be flat or convexly curved in trans-
verse section at the middle part of its width to stiffen it, the inwardly bent
marginal portions being then bent outwards and inwards wise, to form U-shaped
grooves in which the edges of the side plates are received. Instead of the raw

page_text: or cut edge of the sheet metal strip of which the frame is formed being presented
at the outer wall of the groove each marginal portion of the metal may be doubled
or folded on itself so as to present the folded edge at the exterior, the U-grooved
portions being embraced by the intermediate or transverse portion.
According to another form the frame may be simply flanged and pieces partially
punched out at intervals to form inwardly bent clips or staples at a sufficient
distance within the flanges to admit of the edges of the side plates or tooth-like
projections thereon being inserted between the flanges and clips.
Dated this 5th day of October 1896.
A. M & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
I, ALEXANDER MELVILLE CLARK of the Firm of A. M. & Wm. Clark of 53,
Chancery Lane in the County of Middlesex, Fellow of the Chartered Institute of
Patent Agents, do hereby declare the nature of this Invention (a communication
to me by Peter Schlesinger of Offenbach-on-Main, Germany, Manufacturer ;)
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 for object to provide a lighter cheaper, and more durable form
of cycle gear case, and it comprises a peculiarly formed sheet metal rim or peri-
pheral frame in combination with side plates of celluloid, sheet metal, or the like,
the improvements pertaining to the manner in which the case is divided into
halves; to the mode of attachment of the case; and to the mode of connecting
the edges of the flat sides of the case with the peripheral rim. Reference is to be
had to the accompanying drawings forming part of this specification wherein :-
Figure 1 is a side view of the gear case complete Figure 2 shows on a larger
scale the clip and angle piece connecting the case to the back leg of the machine
frame; Figure 3 illustrates the division of the case; Figures 4 & 10 are cross
sections illustrating the construction of the frame of the gear case.
of the frame is composed of a peripheral rim or frame a and side cheeks and as
shown in Figure 3 the joint between the upper and lower halves of the case follows
an approximately Z-shaped line, the joint extending from the crank axle to the
driving wheel axle and being continued upwards from the driving wheel axle and
downwards from the crank axle, thus dividing the gear case into an upper part b
in one with the front rounded end portion and a lower part c in one with the rear
rounded end portion. This form of gear case has the advantage of being easily
fitted, opened, and inspected.
The joints between the upper and lower parts of the gear case are closed by means
of narrow covering strips fastened thereto and which also serve to impart
additional stability.
The upper half b is attached to the machine frame in any suitable manner,
whilst the lower half c is attached to the upper half by means of a pair of slotted
plates and clamping screws so that the upper part having been fixed it is only
necessary to slide the lower part into position and to tighten up the screws. One
of these plates is shown at z Fig. 1 as fixed to the upper half, the screw y being
fixed to the lower half and passed up through the hole in the plate z and secured
by nuta, a similar fastening being provided at the other end of the joint.
Heretofore the gear case has been generally fixed to the stay which extends
transversely through the gear case, but in the present case the peripheral frame a

page_text: of the case is attached to the back leg g of the machine frame whereby a lighter
and more secure attachment is effected and the fitting and removal of the case is
facilitated. A simple means of attachment consists of a sheet metal angle
piece d, k of which the part kis rivetted or screwed to the rim a of the case and
a clip embracing the back leg of the machine frame and connected to the
upstanding slotted part of the angle piece by a screw f and pairs of nuts f¹ f³,
the slot e in the angle piece permitting of necessary adjustment to suit the frame.
The edges of the rim a of the gear case are formed with grooved flanges of
which various forms are shown in Figures 4, 5, 6 to receive the edges of the side
cheeks, the grooved flanges being bent up into the plane of the side plates and
formed with a continuous or interrupted groove in which the edges of the side
plates are inserted and clipped. The grooved flanges which also serve to stiffen
the rim of the gear case may be formed of different shapes and in different ways
by bending, or by punching or stamping, and bending certain parts.
For instance the sheet metal rim a may either be convexly curved in trans-
verse section at the middle part of its width as in Figure 4 or Hat as in Figure 5,
the inwardly bent marginal portions being bent outwards and inwards to form
grooves of U section in which the edges of the side plates are received. Instead
of the raw or cut edge of the sheet metal strip a being presented at the outside of
the case each marginal portion of the metal may be doubled or folded on itself so
as to present the fold at the exterior and the cut edge of the metal at the interior
of the case, the intermediate or transverse portion extending completely across as
shown.
According to another form the rim a may have single flanges as shown in
Figures 9 & 10 in which pieces m are partially punched out at intervals and bent
inwards so as to form clips at a sufficient distance within the flanges to admit of
the edges of the side plates being inserted between the flanges and clips. Or as
shown in Figures 7 & 8 inwardly projecting staple like portions » may be punched
in the flanges to receive tooth like projections on the edges of the side plates.
Having now particularly described and ascertained the nature of the said In-
vention and in what manner the same is to be performed I hereby declare that
what I claim is:-
1. A gear case divided into two parts by a joint extending from crank to driving
wheel axle and thence respectively upwards and downwards, substantially as and
for the purpose specified.
2. A gear case divided into two parts as described and provided with the herein
described means of connecting the two parts as specified.
3. The herein described means of adjustably attaching the gear case to the back
leg of the frame comprising a slotted angle plate attached to the rim of the case,
a screw and a clip embracing the back leg and secured by nuts as specified.
4. The construction of the rim of the gear case of sheet metal with grooved
flanges of U shaped section adapted to receive within the said grooves the edges
of the side cheeks substantially as specified.
5. The construction of the rim of the gear case with single flanges having
clips or staples partially punched out therefrom to retain the edges of the side
cheeks substantially as described.
TI 100%
A. M & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.