Improvements in the Driving Mechanism of Bicycles, Tricycles, and other Velocipedes.
Year: 1895

page_text: Date of Application, 11th May, 1895
Complete Specification Left, 3rd Feb., 1896-Accepted, 14th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in the Driving Mechanism of Bicycles, Tricycles, and
other Velocipedes.
I FREDERICK JOHN OSMOND of Chanty Road, Moseley, in the County of
Worcester Mechanical Engineer do hereby declare the nature of this invention Lo
be as follows:-
My invention has reference to such driving mechanism for bicycles, tricycles and
other velocipedes as consists of an interchangeable driving chain ring secured to
the ends of radial carrying aims keyed on the crank shaft; and my said invention
consists of the improvements herein after described in connecting the said carrying
arms to the interchangeable driving chain ring.
By my invention a very efficient connection of the parts of this kind of diving
mechanism is obtained and the detachment of the said parts, when necessary, 18
readily effected. My invention also permits of the use of unhardcued inter-
changeable driving chain rings with hardened radial cairying arms.
According to my invention I make the diving chain ng of such a sectional
figure that one face of the said ring neni its inner edge 15 provided with a
projecting rib, equi-distant gaps or openings being left by the casting process
in the said rib for the outer ends of the radial connecting arms, on the crank axle,
to fit closely in. The ends of the gaps of cut away parts in the rib of the chain
ring, form shoulders or abutments for the edges of the radial aims, fitted in the
said gaps, to bear against. The bottoms of the gaps or cut away parts of the
chain ring rib are level with the lace of the said ing so that when the radial arms
are introduced into the said gaps, the parts of the arms extending beyond the said
gaps, bear against the flat face of the ung. The inner edge of the chain ring and
its rib may be made alightly comical and each of the radial arms has a shoulde
the outer face of which may also be slightly comical, which shoulder on the arm,
when the latter is passed into the gap in the b of the chain ring seats itselt
against the inner edge and rib of the cham ing. The conical seatings or abutting
parts of the shoulder and ing are ground so that a very accurate fitting of the
parts is secured.
After the radial connecting arms on the crank axle have been fitted in their
respective gaps in the chain ring, each of the said arms is held on bound in its
place by a screw pin passed, from the unribbed side of the chain ring, through a
large hole or clearance in the said mng and screwed into the extreme end of the
arm.
By thus connecting the indial arms on the crank axle to the driving chain ring,
the thrust of the said arms upon the said ng 18 borne only at the shoulders or
abutments formed by the ends of the gaps in the rib of the chain ing, there being
no strain upon the chain ring at the holding or binding screw pius at the extreme
enda of the arms in consequence of the holes or clearances in the said ring through
which the said solow pins pass.
DL: Til 1005
W. T. WHITEMAN,
Agent for the Applicant.

page_text: Improvements in the Driving Mechanism of Bicycles, Tricycles, and
other Velocipedes.
I FREDERICK JOHN OSMOND, of Chantry Road, Moseley, in the County of
Worcester, Mechanical Engineer, do hereby declare the nature of my 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 has reference to such driving mechanism for bicycles, tricycles and
other velocipedes as consists of an interchangeable driving chain ring secured to
the ends of radial carrying arms keyed on the crank shaft; and my said invention
consists of the improvements hereinafter described in connecting the said carrying
arms to the interchangeable driving chain 11ng.
By my invention a very efficient connection of the parts of this kind of driving
mechanism is obtained, and the detachment of the said parts, when necessary, is
readily effected. My invention also permits of the use of uubardoned inter-
changeable driving chain rings with hardened radial carrying arms.
According to my invention I make the diving chain ing of such a sectional
figure that one face of the said ring near its inner edge is provided with a
projecting rib, equi-distant gaps or openings being left in the said rib for the outer
ends of the radial connecting arms, ou the crank axle to fit closely in. The ends
of the gaps or cut away parts in the rih of the chain ring, form shoulders or
abutments for the edges of the radial arms, fitted in the said gaps, to bear against.
The bottoms of the gaps or cut away parts of the chain ring rib are level with
the face of the said ring so that when the radial arms are introduced into the said.
gaps the parts of the arms extending beyond the said gaps, bear against the flat
face of the ring. The inner edge of the chain ring and its rib may be made slightly
conical and each of the radial arms has a shoulder the outer face of which may
also be slightly conical, which shoulder on the arm when the latter is passed into
the gap in the rib of the chain ring seats itself against the inner edge and rib of
the chain ring. The conical seatings or abutting parts of the shoulder and ring
are ground so that a very accurate fitting of the parts is secured. After the
radial connecting arms on the crank axle have been fitted in their respective gaps
in the chain rings each of the said arms is held on bound in its place by a screw
pin passed from the unribbed side of the chain ring through a large hole or
clearance in the said ring and screwed into the extreme end of the arm.
By thus connecting the radial arms on the crank axle to the driving chain ring
the thrust of the said aims upon the said ring is borne only at the shoulders or
abutments formed by the ends of the gaps in the rib of the chain ring, there being
no strain upon the chain ring at the holding or binding sciew pins at the extreme
ends of the arms in consequence of the size of the holes or clearances in the said
ring through which the said screw pins pass.
Figure 1 of the accompanying drawings represents an elevation of the inner
side of a driving chain ring and combined crank and chain ring carrying arms
constructed and connected together according to my invention, Figure 2 represents
a vertical section of the same taken on the line a, x Figure 1; Figure 3 represents
an elevation of the outer side of a portion of the chain ring and one of the
carrying arms of the same and
Figure 4 is a section on the dotted line y, y Figure 3.
Figures 5, 6, 7 and 8 represent the chain ring and combined crank and radial
chain ring carrying arms detached.
The same letters of reference indicate the same parts in the several Figures of

page_text: In constructing interchangeable driving chain rings according to my invention
I form on the outer face of each of the said rings a projecting annular rib or
flange a provided at the parts where the chain ring carrying arms b, b, b are to be
connected to it with gaps or unflanged parts a³, a', a' in which gaps the ends of the
Baid radial chain ring carrying arms b, b, b accurately fit, the edges of the arms
when driving bearing against one or other of the shoulders or abutments aº, a³ at
either side of the gaps a².
The radial chain ring carrying arms b, b, b are provided with curved shoulders b
for taking a bearing against the inner side or edge of the driving chain ring (see
Figures 2, 3 and 4) and thereby obtaining perfect concentricity in the fixing of
the said ring to the radial arms. Where thought necessary or desirable the inner
edge of the chain ring may be made slightly conical the outer or bearing sides of
the curved shoulders & having a corresponding figure, the inner edge of the ring
and the bearing side of the shoulders 6 being ground so as to accurately fit one
another.
When the interchangeable driving chain ring is applied to the railial chain ring
carrying aims b, screw pins c, c, c are passed through holes a, a, a' in the face of
the wheel into screwed holes 63, 6, 6 in the ends of the radial chain ring carrying
aims b.
It will be seen by an examination of Figures 2 and 4 that the
holes a, a, a' in the chain ring are of a larger diameter than the stems of the
screw pins c, c, c so that on the driving of the chain ring no shearing strain is put
on the connecting screw pins c, c, c the pressure of the radial chain ring carrying
arms b being borne solely by the shoulders or abutinents aº, as of the rib or flange a
formed by the gaps a', a', a² in the said rib or flange a.
The bush of the combined crank and radial chain ring carrying arms is
connected to the crank axle in the ordinary way.
Although I have shown my invention in connection with a combined crank and
radial chain ring carrying arms yet I wish it to be understood that it is equally
applicable to radial chain ing carrying arms which are formed separate from the
crank and are keyed independently to the crank axle.
Having now particularly described and ascertained the nature of my inven
tion and in what manner the same is to be performed I declare that I claim
as my invention of "Improvements in the driving mechanism of bicycles, tricycles,
and other velocipedes " ;-
Pioviding interchangeable driving chain rings with a rib or flange on one side
the said rib or flange having gaps or spaces at the parts where the radial chain ring
carrying arms are to be connected to the said interchangeable driving chain rings
the holes in the said rings for the fastening screw pins to pass through being of
such a size that the said screw pins do not fit tightly therein, the edges of the
radial chain ring carrying arms bearing against the abutments or shoulders formed
by the gaps in the rib or flange of the chain ring the said radial chain ring
carrying arms being provided with shoulders for engaging under the inner side of
the chain ring substantially as and for the purpose herein before described and
represented in the accompanying drawings.
Dated the 27th day of January 1896.