improvements in velocipedes.
Year: 1891

page_text: Date of Application, 12th Jan., 1891-Accepted, 21st Feb., 1891
improvements in velocipedes.
A communication from CHARLES FREDERICK STOKES, of 247, Oakwood
Boulevard, Chicago, Illinois, United States of America.
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 :-
My invention relates to improvements in velocipedes generally, though certain
features thereof are especially designed for "safety" bicycles, my object being to
provide improved propelling mechanism, whereby when the velocipede is in motion,
and particularly in coasting, the pedals may be held against rotation to afford a
rest for the feet of the operator without obstructing the movement of the wheels,
and whereby the pedals may then be controlled by the rider to exert a braking
effect upon the driving wheel. My object is further, to provide a new and increasedly
effective disposition of spring-mechanism in a velocipede, for enhancing the comfort
of the rider.
In the drawing--
Figure 1 is a view in elevation of a safety bicycle provided with my improvement;
Figure 2, an enlarged broken section taken on line 2 of Figure 1, and viewed in
the direction of the arrows;
Figures 3 and 4 enlarged detail views of the propelling mechanism; and
Figure 5, a broken view showing a modified construction.
The framework of the bicycle illustrated comprises a front-fork, A, a frame in
the nature of a backbone, B, and a frame, C, integral with each other, constituting
together the seat-supporting frame, and a rear-fork or driving-wheel frame, D. The
seat supporting frame is provided on its rear side and near its lower extremity with
an off-set or shoulder, t, which is strengthened by a brace, t', extending upward to
the said frame, as shown. On the underside of the frame B, C, is an ear, s, to which
the rear-fork is pivotally secured at its forward end. Upon the rear-fork directly
under the shoulder t is a boss, r, from the centre of which rises a rod or bolt,
threaded along its upper portion which extends loosely through an opening in the
shoulder. About the bolt r¹ is a coiled spring, q, which bears at opposite ends,
respectively, against the boss and underside of the shoulder t; and on the upper
side of the shoulder the bolt is provided with a nut, q', which by bearing against
the upper side of the off-set holds the parts together against the resistance of the
spring, and which may be tightened or loosened to increase or diminish the tension
of the spring when desired. Owing to the nature of the construction the weight of
the rider is borne, mainly at least, by the spring q which affords a cushion to diminish
the jolting effect upon the rider in traversing rough roads. The spring q is of stiff
quality and its expansion and contraction is within such short limits that in its action
with the pedals in the position shown no such lengthening and shortening of the
distance between the saddle and pedals occurs as would prove objectionable to the
rider. However, such variations in distance between the seat and pedals could be
readily decreased or overcome by moving the bearing for the pedal shaft toward or
to the point of pivotal connection between the frames. Although the spring 9 acts
more especially to cushion the seat-supporting frame against the jolting of the rear-
wheel, which jolting, that wheel being most nearly under the rider, would, neces-
sarily, the more immediately affect him, inasmuch as the weight of the rider is
distributed over both wheels, the spring a will, obviously, also in a measure exert its
cushioning effect against jolting to which the forward wheel is subjected. To further

page_text: neutralize any jolting effect from the front wheel, however, I provide a front-fork of
the construction shown and to be described.
Pivotally supported upon the axle of the front wheel, at opposite sides of the
latter, are links p, to the free ends of which the ends of the fork A are pivotally
secured. Upon the forks and extending over the links near the latter are off-sets
or shoulders o. Rods or bolts n extend upward from the links above the axle,
and through openings in the shoulders o. About the bolts between the links and
shoulders are springs m, and the bolts are threaded along their upper portions to
receive nuts m which hold the parts in position and by means of which the tension
of the springs may be regulated, if desired. The front-fork and weight sustained
thereby exert their pressure upon the springs m, the links operating merely to afford
the necessary secure connection between the front-fork and axle.
If desired, the off-sets shown may be dispensed with and the shoulders afforded
by bends in the forks, in which case the upper portions of the forks would extend
in direct line with the rods n, and therefore in direct line with the expansion and
contraction of the springs m, as shown in Figure 5.
Upon the pedal shaft, E, near one end is an independently rotary wheel or disk l,
provided with a peripheral laterally extending rim, ', on its outer side and a hub, 12,
on its inner side, formed with a smooth annular bearing surface, l, around its periphery.
The hub abuts and rotates against the ball bearing, . The sprocket-wheel, F,
which drives the rear-wheel of the bicycle through the medium of the usual
link-belt, is also in the form of a disk with a central opening at which it fits and
rotates upon the bearing surface 13, and a peripheral laterally extending rim k,
which projects over the rim of the part l, and has its inner periphery formed with an
annular friction surface, k'. The sprocket wheel is held in place by a collar, i,
upon the hub.
On the face of the disk bounded by its rim are sliding
blocks, which may be in the form of plungers, working through openings in
the rim and held in place by lateral guides . The plungers are provided with
springs which bear against the rim and tend, normally, to force the plungers
inward toward the centre of rotation of the disk. The plungers are formed with
rounded inner ends, ³, as shown. Upon the shaft E and preferably integral there-
with is a cam disk, g, formed around its periphery with alternate round and hollow
surfaces, as shown. When the rounded ends of the plungers are in the hollows of
the cam disk, the outer ends of the plungers are out of frictional contact with the
surface, of the sprocket-wheel; turning of the pedal-shaft in either direction,
however, causes the plungers to be forced outward by the cam contrary the resistance
of their springs, against the surface of the sprocket-wheel, which they grip,
causing the latter to turn with the shaft. A circular plate, f, removably secured to
the shaft, fits loosely into the rim and operates as a housing or dust-guard for the
plungers and attendant parts.
The intermittent gripping mechanism described may be so adjusted as to grip
and release without apparent lost motion, and as the drive-wheel may be turned
to travel forward or backward, by the pedals, and as the velocipede may travel
without consequent rotation of the pedals, the grip being released when the
pedals are at rest, the rider may rest his feet upon the pedals while coasting.
He is thus able to maintain perfect control over the motion of the device, as in case
of too high speed or danger of accident, he may exert a desired degree of pressure
in the reverse direction against the pedals, which will cause the gripping mechanism
to operate as a supplemental brake.
Two plungers, h, I believe to be ample under all circumstances, to produce the
necessary gripping effect against the rim k, though more plungers could be readily
provided if desired. The periphery of the cam-disk g, shown, is provided with four
hollows alternating with the rounded portions, so that in case of wear upon the two
cam surfaces in use, the disk may be turned to present new hollows, and thus
prolong the usefulness of the cam.
The off-set t and its brace t', besides affording a bearing for the spring 9,
materially to the strength of the seat-supporting frame.
add

page_text: The intermittent-grip mechanism, described, and the cushioning springs, are all
subject to slight variations, in the matter of details of construction, which would
not change the functions of those parts or depart from the spirit of my invention as
set forth in the claims.
Having now particularly described & ascertained the nature of the said inven-
tion, 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-In a velocipede, the combination with the seat-supporting frame of a rear-
wheel frame pivotally connected with the seat supporting frame, and a spring
interposed between the said frames adjacent to their pivotal connection, sub-
stantially as and for the purpose set forth.
2-In a velocipede, the combination with a vertically extending seat-supporting
frame, of a rear-wheel frame pivotally connected at its forward end with the lower
end of the seat supporting frame, and extending at an angle therefrom, and a spring
confined in the angle between the two said frames near their pivotal connection,
substantially as and for the purpose set forth.
3-In a velocipede, the combination with a vertically extending seat-supporting
frame, of a rear-wheel frame pivotally connected at its forward end with the seat
supporting frame, and extending at an angle therefrom, a spring confined in the
said angle adjacent to the said pivotal connection and bearing at opposite ends
against the said frames respectively, and stop mechanism, as the bolt g and its nut q',
for limiting the distance of separation of the said frames, substantially as and for
the purpose set forth.
4 In a velocipede, the combination with a vertically disposed seat-supporting
frame, of a rear-wheel frame pivotally connected at its forward end with the lower
end of the seat-supporting frame and extending at an angle therefrom, a shoulder, t,
upon the seat-supporting frame, a brace, 1, extending upward from the said
shoulder to the said frame, a spring confined in the angle between the two frames
and bearing at opposite ends, respectively, against the shoulder t and rear-wheel
frame, and a rod, r', upon the rear-wheel frame extending through an opening in
the said shoulder and limiting the distance of separation of the two frames, sub-
stantially as and for the purpose set forth.
5-In a velocipede, the combination with the seat-supporting frame, of a front-
fork, A, links p pivoted at one end upon the front-wheel shaft and extending at an
angle to the front fork to which they are pivotally connected at their opposite ends,
shoulders upon the front-fork near the links, and springs confined between the said
shoulders and links, substantially as and for the purpose set forth.
6 In a velocipede, the combination with the seat-supporting frame, of a front-
fork, A, links, p, pivoted at one end upon the front-wheel shaft and extending at an
angle to the front-fork to which they are pivotally connected at their opposite ends,
shoulders upon the front-fork above the links, springs confined between the said
shoulders and links, and rods provided with suitable stops and extending between
the links and shoulders and operating to limit the extent of rise of the shoulders
from the front-wheel shaft, substantially as and for the purpose set forth.
7-In a velocipede, the combination with the pedal-shaft, and drive-wheel,
loosely mounted thereon, of intermittent-grip driving-mechanism between the said
shaft and drive-wheel, operating to release the drive-wheel from the shaft when the
pedals are at rest, and to grip the said wheel by working the pedals in either
direction, substantially as described.
8 In a velocipede, the combination with the pedal-shaft, of an independently
revoluble drive-wheel thereon having a laterally extending rim provided with an
annular inner surface, k¹, a cam rigid upon the shaft bounded by the surface k' and
formed with one or more hollows in its face having sloping sides, and one or more
loose grippers interposed between the cam and surface k in the said hollows, and
normally out of frictional contact with the said surface, and forced into frictional

page_text: contact therewith by movement of the cam in either direction of working the
pedals, substantially as described.
9-In a velocipede, the combination with the pedal-shaft, of an independently
revoluble drive-wheel thereon having a laterally extending rim provided with an
annular inner surface k¹, a cam rigid upon the shaft bounded by the surface k¹ and
formed with one or more hollows in its face having sloping sides, a wheel, 7, loose
upon the shaft and interposed between the cam and drive-wheel, and one or more
spring actuated sliding blocks / supported in guides upon the wheel between the
cam and surface k¹, and maintained by their springs normally in the hollows of the
cam face, out of frictional contact with the surface ³, and forced against
the resistance of their springs into frictional contact with the said surface by
movement of the cam in either direction of working the pedals, substantially as
described.
Dated this 12th dox of January 1800
W. P. THOMPSON & BOULT,
Agents for the Applicant.