Year: 1887

page_text: A communication from FRANCIS ROURK, of 205, Wellington Street, London, in the
County of Middlesex, and Province of Ontario, Dominion of Canada, Physician.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
M.I.M.E., 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 improvements in cycles and velocipedes of all descriptions
the object being to prevent loss of power in the pedal passing a centre. It consists of
a method of effecting rotation by means of a spur wheel which engages with a pinion
centred on the axle of the traction wheel and transmitting motion thereto the spur
wheel being operated by a pawl or block attached to a bar which also carries the
pedal.
The accompanying side elevation of a bicycle with the attachment illustrates this
invention.
A is the front traction wheel of a bicycle. B the axle and C the fork. D is a
pinion centred on axle B which revolves with it. E is an arm or bracket extending
from the fork and strongly braced thereto. F is a spur wheel pivoted on this arm or
bracket E, the cogs or teeth on the outer rim of which engage with pinion D.
G is a bar or rod pivoted to arm E and carrying the pedal H. I is a pawl or block
attached to the bar G by a pin or bolt passing through both so as to leave the pawl
free to oscillate up and down in its centre. One end a of this pawl is weighted or
controlled by a spring so that when at rest the other end 6 will be thrown up. When
the pedal H is pressed down by the rider's foot the upper end of the bar G is also
depressed and the pawl I is carried down with it so that the end 6 is pressed tightly
against the rim of the spur wheel and causes the latter to partially revolve either by
the downward pressure of the end of the pawl or block against it or by the engagement
of the said pawl or block with the teeth on the inside of the rim of spur wheel, as
shown in drawing, or on the outside of said rim of spur wheel in which case the pawl
[ Price 6d 1

page_text: or block is sufficiently prolonged. This pressure is continued from about the point
marked c down to that marked d in the arc of dotted lines in drawing and thus all loss
of power in passing a centre is prevented, as the section of the spur wheel over which
the
pressure of the pawl or block is exerted covers only the core of the freest movement
of the spur wheel.
J is a spring one end of which is attached to the arm E and the other to the bar G
and as soon as the rider's foot is raised after completing the down stroke of the pedal
this spring brings the bar G back to its normal upright position and with it the
pedal and pawl thereto attached, the weighted end a of the pawl raising the other end b
and freeing it from contact with the spur wheel in this upward motion.
A pin stud or shoulder on bar G above the pawl prevents its end b from rising too
high and a similar contrivance beneath the pawl acts as a bearing to it in the down-
ward stroke and prevents it from dropping too low.
Having now particularly described and ascertained the nature of the said invention,
as communicated to me by my foreign correspondent, and in what manner the same
is to be performed, I declare that what I claim is :-
1. The above described method of transmitting motion to the axle of the wheel or
wheels of a cycle or velocipede the same consisting of a pinion centred on the said
axle and a spur wheel engaging therewith, the spur wheel being operated by the
pressure of a pawl or block attached to a bar which also carries the pedal and
participates in the up and down movement of the said pedal substantially as shown
and specified.
.
2. În a cycle or velocipede the above described combination of pinion D attached
to axle B and engaging with spur wheel F carried on arm E substantially as shown
and specified.
3. In a cycle or velocipede, the combination of bar G, pivoted to arm E, pedal H,
pawl I and spring J substantially as shown and specified.