Improvements in or relating to Cranks, Crank-axles and Chain-wheels for Cycles and similar Machines.
Year: 1899

page_text: Date of Application, 12th Sept., 1899
Complete Specification Left, 12th June, 1900-Accepted, 28th July, 1900
PROVIDIONAL DIEVITICATION.
Improvements in or relating to Cranks, Crank-axles and Chain-wheels
for Cycles and similar Machines.
I, THEODORE JAMES BIGGS, of Dungarvon Buildings, Frome, Somerset,
Engineer, do hereby declare the nature of this invention to be as follows:-
The first part of this invention relates to the cranks, crank-axles, and chain-
wheels or gear-wheels of cycles and similar machines, and refers more particu-
larly to improved methods of fixing the cranks and chain-wheels to the crank-
axle. The second part relates to cycle chain-wheels and improved methods by
which they are manufactured.
According to one method of constructing a crank and crank-axle according to
my invention, the boss of the crank is recessed on its inner side to allow the
crank-axle bearing to project into it, a wider crankaxle bearing being thereby
obtained. The end of the crank-axle is provided with an enlarged head or
flange which enters into the recess in the crank-boss, and the crank is secured
to the crank-axle flange by means of rivets. These rivets may be separate
members passing through holes drilled in the crank and the crank-axle flange;
or they may be made integral with the crank-axle flange and pass through holes
in the crank; or they may be made integral with the crank and pass through
holes in the crank-axle flange.
According to another method, by means of which the crank, chain-wheel and
crank-axle are secured together: the chain wheel is provided with an outwardly
projecting boss which enters the recess in the crank-boss. The inward side of
the chain-wheel boss is recessed to receive the crank-axle flange, and the three
parts, namely, crank, chain-wheel, and crank-axle, are secured together by
means of rivets as before described.
By another method of securing the crank to the crank-axle, the crank-axle
flange is provided with integral bosses which project into recesses formed in
the crank-boss recess, for the purpose of taking the driving strain, and screws
pass through the crank and into the said integral bosses for the purpose of
securing the crank to the crank-axle. The same method is also applicable
when the crank, chain-wheel, and crank-axle are to be connected together.
According to another method of securing the crank, chain-wheel and crank-
axle together, the crank-axle flange is provided with bosses or projections
which enter recesses formed in the crank-boss recess. The crank-boss recess
is provided with an internal screw thread which receives an external screw
thread provided on the chain-wheel boss. The chain-wheel_boss_is_screwed-
into-the-crank-boss recess and impinges against-the crank-axle flange in such a
manner as to draw the crank and crank-axle tightly together. The driving
strain acting upon the chain-wheel keeps the parts screwed up tightly together,
and any suitable means may be provided, for preventing a reversal of the driv-
ing strain from unscrewing the chain-wheel.
The same method is also applicable when the crank and crank-axle are to be

page_text: connected together without a chain-wheel. In this case a screwed ring is used
to act as a substitute for the chain-wheel.
The before mentioned projections on the crank-axle flange may be formed
integral therewith; or recesses may be formed in both the crank-boss recess
and the crank-axle flange, and suitably shaped pieces of metal inserted therein;
or any other suitable means may be provided for transmitting the driving
strain between the crank-axle and the crank.
the
In making a chain-wheel according to my invention, I form
arms or web of the wheel from circular metal plate which may be pierced,
pressed, or stamped to any desirable shape. In order to provide the wheel
with a rim which shall be of greater thickness than the web, I wrap a strip
of metal around the periphery of the web-plate, turn it down for a suitable
distance on either side, and secure it thereto by suitable means.
Preferably the thickening strip is made by forming by suitable stamping or
pressing operations from sheet metal a washer having an annular flange thrown
up around its outer edge. The web-plate is then inserted so as to lie within
the flange which is then folded down upon the web-plate by means of pressing,
inning, or other suitable operations.
By another method, the thickening strip is formed by rolling a strip of sheet
metal to the required section and wrapping it around the web-plate; or it may
be made in the form of an endless band and folded over the web-plate by press-
ing, spinning or other suitable operations.
The thickening strip may be secured to the web-plate by means of heavy pres-
sure applied in the spinning or pressing operations, or by rivetting, soldering,
brazing or other suitable means.
The thickening strip may be so shaped as to provide annular flanges upon
either side. of the wheel, for the purpose of strengthening the wheel laterally,
or for providing a seating for the side-plates of the chain.
The teeth of the wheel are cut in the rim in the ordinary manner.
Datad this 10th
C
1000
Improvements in or relating to Cranks, Crank-axles and Chain-wheels
for Cycles and similar Machines.
I, THEODORE JAMES BIGGS, of Dungarvon Buildings, Frome, Somerset,
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:--
The first part of this invention relates to the cranks, crank-axles and chain-
wheels or gear wheels of cycles and similar machines, and refers more particu-
larly to improved methods of fixing the cranks and chain-wheels to the crank-
axle. The second part relates to cycle chain-wheels and improved methods by
which they are manufactured.
According to one method of constructing a crank and crank-axle according to
my invention, the boss of the crank is recessed on its inner side to allow the
crank-axle bearing to project into it, a wider crankaxle bearing being thereby
obtained. The end of the crank-axle is provided with an enlarged head or
flange which enters into the recess in the crank boss, and the crank is secured
to the crank-axle flange by means of rivets. These rivets may be seperate
members passing through holes drilled in the crank and the crank-axle flange;

page_text: or they may be made integral with the crank-axle flange and pass through holes
in the crank; or they may be made integral with the crank and pass through
holes in the crank-axle flange.
According to another method, by means of which the crank, chain-wheel and
crank-axle are secured together; the chain-wheel is provided with an outwardly
projecting boss which enters the recess in the crank boss. The inward side of
the chain-wheel boss is recessed to receive the crank axle flange, and the three
parts, namely, crank, chain-wheel, and crank-axle, are secured together by
means of rivets as before described.
By another method of securing the crank to the crank-axle, the crank-axle
flange is provided with integral bosses which project into recesses formed in
the crank boss recess, for the purpose of taking the driving strain, and screws
pass through the crank and into the said integral bosses for the purpose of
securing the crank to the crank-axle. The same method is also applicable
when the crank, chain-wheel, and crank-axle are to be connected together.
According to another method of securing the crank, chain-wheel and crank-
axle together, the crank-axle flange is provided with bosses or projections
which enter recesses formed in the crank boss recess. The crank boss recess
is provided with an internal screw thread which receives an external screw
thread provided on the chain-wheel boss. The chain-wheel boss is screwed
into the crank boss recess and impinges against the crank axle flange in such a
manner as to draw the crank and crank axle tightly together. The driving
strain acting upon the chain wheel keeps the parts screwed up tightly together
and any suitable means may be provided for preventing a reversal of the driv-
ing strain from unscrewing the chain wheel.
The same method is also applicable when the crank and crank-axle are to be
connected together without a chain-wheel. In this case a screwed ring is used
to act as a substitute for the chain-wheel.
The before mentioned projections on the crank-axle flange may be formed
integral therewith; or recesses may be formed in both the crank boss recess
and the crank-axle flange, and suitably shaped pieces of metal inserted therein;
or any other suitable means may be provided for transmitting the driving
strain between the crank-axle and the crank.
In making a chain-wheel or gear-wheel according to my invention, I form the
arms or web of the wheel from a circular metal plate which may be pierced,
pressed, or stamped to any desirable shape. In order to provide the wheel
with a rim which shall be of greater thickness than the web, I wrap a strip
of metal around the periphery of the web-plate, turn it down for a suitable
distance on either side, and secure it thereto by suitable means.
Preferably the thickening strip made by forming by suitable stamping or
pressing operations from sheet metal a washer having an annular flange thrown
up around its outer edge. The web-plate is then inserted so as to lie within
the flange which is then folded down upon the web plate by means of pressing,
spinning, or other suitable operations.
By another method, the thickening strip is formed by rolling a strip of sheet
metal to the required section and wrapping it around the web-plate or it may
be made in the form of an endless band and folded over the web-plate by press-
ing, spinning or other suitable operations.
The thickening strip may be secured to the web-plate by means of heavy pres-
sure applied in the spinning or pressing operations or by rivetting, soldering,
brazing or other suitable-means.
The thickening strip may be so shaped as to provide annular flanges upon
either side of the wheel for the purpose of strengthening the wheel laterally,
or for providing a seating for the side-plates of the chain.
The teeth of the wheel are cut in the rim in the ordinary manner.
With reference to the accompanying drawings-In Figs. 1 to 8 inclusive A.
denotes the crank-axle,.

page_text: A, the crank,
B, the recessed boss of the crank,
C, the web or arms of the chain-wheel,
W, the boss of the chain-wheel.
In Figs. 1 & 2 the crank-axle A is shown with a flange F, which
is provided with the projections R, formed integral therewith and
passing through holes in the crank boss B. The projections R are rivetted
or otherwise secured in the holes in the crank boss and the crank-axle and
crank are thereby secured together.
Instead of making the projections R integral with the crank-axle flange F
I sometimes drill holes through both the flange F and the crank-boss B and
pass rivets through both and thus secure the parts together.
Figs. 3 & 4 show a method of securing. a crank-axle, chain-wheel and crank
together. The recessed chain-wheel boss W is inserted between the crank-axle
Hange F and the recessed crank boss B, and the three parts are secured together
by rivetting the integral projections R as before described, or by rivets H,
also as before described.
Figs. 5 & 6 show another method of securing a crank, chain-wheel and crank-
axle together. The projections R on the crank-axle flange F pass through the
chain-wheel boss W and enter holes in the crank boss B and thereby transmit
all driving strain between the parts concerned. Screws N are inserted into
the projections R in such a manner that their heads impinge against the outer side
of the crank boss B and thus hold the crank boss, chain-wheel boss and crank-axle
flange together.
Figs. 7 & 8 show another method of securing a crank-axle, chain-wheel and
crank together. Holes or recesses are formed in the crank-boss B of suitable
shape to receive the projections R on the crank axle flange F. The crank boss B
is provided with an internal screw-thread to receive the chain-wheel boss W
which is screw-threaded externally and impinges against the crank-axle flange F
and thereby secures the crank, crank-axle at a pace par
screw threads are of such a hand that the driving strain transmitted to the
chain-wheel tends to screw the chain-wheel boss into the crank boss and thus
keep all parts concerned firmly in position. In such cases as make it necessary
to provide for both forward and backward driving strains, I screw the chain-
wheel boss tightly into the crank boss and against the crank-axle flange and
insert a pin or screw S through both the chain-whteel boss
and crank boss. Instead of making the projections R integral with
the crank-axle flange, I may form holes or recesses in both the crank-axle
flange and the crank boss B and insert pieces of metal E to transmit the driv-
ing strain between the crank and axle.
In each case where the chain-wheel boss is herein mentioned, it may be an
integral part of the chain-wheel, or it may be an integral part of the arms to
which the chain-wheel is sometimes affixed by screws.
Figs. 9 to 14 inclusive show chain-wheels or gear-wheels made according to
my invention. In each fig. T denotes the plate forming the web or arms of the
wheel, and the thickening strip which increases the thickness of the wheel
around its periphery so as to form a rim in which teeth may be cut.
Fig. 9 shows a section of a finished wheel with a U shaped thickening strip O
wrapped around the periphery of the web-plate T.
Fig. 10 shows a wheel made in a similar manner but with the thickening
strip of such a shape as to provide annular flanges X which may be used to
form seatings for the side-plates of the chain or for other purposes.
Fig. 11 shows a method which I sometimes employ for forming the thickening
strip on the wheel. The thickening strip O is first made in the form of a washer

page_text: as shown, the web-plate T is then placed in the position shown and the portion 0¹
of the thickening strip extending beyond the web-plate is folded back over the
web-plate by suitable pressing or spinning operations until it takes the form
shown in Figs. 1 or 2, as may be desired.
Figs. 12 & 13 show the method which I preferably employ for forming the
thickening strip on the wheel. I first form from sheet metal a shallow circular
dish and pierce out a portion of its bottom so as to leave the thickening strip
U in the form of a flanged washer of the sectional shape shown in Fig. 12. I
then insert the web-plate so as to lie within the said flange and by suitable
pressing or spinning operations I then fold the thickening strip over as shown
in Fig. 13 and finally close it down upon the web-plate T as shown in Fig. 9,
or by a slight variation in the tools used I may finally leave the thickening strip
of the sectional shape shown in Fig. 10.
Fig. 14 shows another method which I sometimes employ. I wrap a band O
around the periphery of the web-plate T and then by suitable pressing or
spinning operations I fold it down on either side of the web plate until it
assumes either the sectional shape shown in Fig. 9 or that shown in Fig. 10.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. The method of securing a crank to a crank-axle by means of rivetting the
recessed crank boss to a flange provided on the crank-axle, substantially as
herein described and shown with reference to Figs. 1 & 2 of the accompanying
drawings.
2. The method of securing a crank, chain-wheel and crank-axle together by
rivetting the crank boss, chain-wheel boss and crank-axle flange together sub-
stantially as herein described and shown in Figs. 3 & 4 of the accompanying
drawings.
3. The method of securing a crank, chain wheel and crank-axle together by
means of projections on the crank-axle flange, and screws, substantially as herein
described and shown in Figs. 5 & 6 of the accompanying drawings.
4. The method of securing a crank, chain-wheel and crank-axle together by
means of an externally screw-threaded chain-wheel boss screwing into an inter-
nally screw-threaded recessed crank boss and impinging against a flange pro-
vided on the crank-axle for the purpose, substantially as herein described and
shown in Figs. 7 & 8 of the accompanying drawings.
5. The method of making a chain-wheel or gear wheel by thickening the sides
of a metal plate near its outer edge, with a separate piece of metal wrapped around
the outer edge of the said metal plate and folded down upon the sides thereof so
as to form a thickened rim in which the teeth may be cut, substantially as herein
described and shown in Figs. 9 to 14 inclusive of the accompanying drawings.
Dated the 11th day of June 1900