Improvements in Mechanism for Converting Reciprocating into Rotary Motion in Velocipedes and other Machines.
Year: 1896

page_text: Date of Application, 15th Oct., 1896-Accepted, 12th Dec., 1896
COMPLETE SPECIFICATION.
Improvements in Mechanism for Converting Reciprocating into
Rotary Motion in Velocipedes and other Machines.
I, LUCIEN STEPHEN CRANDALL of the Village of Parish, County of Oswego, and
State of New York, United States America, Gentleman, 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 driving gear for velocipedes and similar
purposes, and has for its object to convert a reciprocating action of the crank
extremities into a rotary motion of the driving wheel of a velocipede or of the part to
which a rotary motion is required to be communicated in other applications of my
invention.
My invention is capable of general application but is more especially applicable for
useful results to bicycles and other velocipedes.
The object of my invention in its application to velocipedes is to allow of the motion
thereof without a necessary corresponding motion of the driving crank nor that of the
feet of the rider, so that upon a sufficient velocity having been attained or when it is
not desirable to further propel by pedalling, the pedal cranks may rest, and all action
on the part of the rider may be suspended until such time as it may be desirable to
further propel the machine.
The further object of my invention is to enable any length of stroke of the pedal
crank within certain extreme limits, so that when it is desired to propel the machine
slowly a shorter stroke only may be taken or one at shorter intervals than normally
necessary, so that the rider may regulate the speed of his machine with precision.
My invention has also for its object to vary the rate of speed of the machine with
the same stroke of the pedals, so that the driving effort may be adjusted to suit the
direction and degree of gradient.
The accompanying drawings illustrate my invention as applied for the purpose of
the propulsion of a safety bicycle:-
Figure 1 is a side elevation of a velocipede showing my invention applied.
Figure 2 is a sectional front elevation of the driving pedal crank lever, while
Figure 3 is a side elevation thereof, and
Figure 4 is a plan of the driving arm; and
Figure 5 is a section thereof.
Figure 6 is a modified arrangement of the driving arm.
Figure 7 is a sectional side elevation of the hub of the driving wheel, while
Figure 8 is a sectional elevation transversely thereto, and
Figure 9 is a side elevation corresponding to Figures 7 and 8.
In carrying my invention into effect when constructing a machine applied with
driving gear according to my invention I provide a fixed axle A in a bracket B
arranged at the junction of the lower extremities of the members of the frame, which
bracket in velocipedes of this type usually carries a rotating driving axle. I provide
upon each of the extremities of this fixed axle a pair of oppositely disposed ball races c
formed in the laterally inclined peripheries of oppositely disposed flanged discs C.
These flanged discs CC are placed in close proximity and fit upon the square sectioned
extremity of the pivotting axle A, a suitable distance ring D being interposed and the
discs maintained at the minimum distance apart to secure lateral rigidity.
The crank boss E is provided to work upon the balls C, two ball races being

page_text: provided so as to correspond with the opposing races formed in the flanged discs.
The crank F is provided integral with the boss E and it will be seen that the effort
communicated to the pedal will produce the rotation of the crank boss E upon the ball
bearings c, while the flanged discs C will be rigidly held.
An arm G is integrally provided upon the crank boss in a determined position which
is approximately at right angles to that of the crank F, and has secured to its
extremity by means of a nipple the end of a driving rope H or chain. The opposite
extremity of this rope or chain is disposed around a collar I free to independently
rotate in one direction and is secured after passing round such collar in the peripheral
bed provided thereon, in such a manner as indicated at J. The collar I is mounted
in ball bearings i which are formed respectively by races provided upon the inclined
lateral underfaces of the collar and upon the inclined lateral face of the hub K of the
driving wheel, and upon the inclined lateral face of a fixed flanged disc L secured
upon the extremity of the shaft. The carrying jaw M of the machine frame is
provided upon either side in proximity to the disc L and is pressed into contact
therewith by the nuts m.
The fixed flanged disc L encloses a spiral spring N the outer extremity of which is
suitably secured to the inwardly projecting face or flangej of the collar I, while its
inner extremity is suitably secured to the fixed axle O.
The inner circumference of the collar I is provided with series of recesses P of a
form shewn in Figure 7, in, each of which are provided rollers Q of a length
corresponding to that of the recess. The recesses P together with the periphery of
the projecting lateral flango k and the vertical flange j, form chambers in which the
rollers P are confined, and in which they are retained with their axes in alignment
with that of the fixed axle O.
It will be seen that on the rotation of the collar I in the direction indicated by the
arrows in Figure 7, that each roller upon the right side will drop into contact with
the inclined face of its recess and the periphery of the hub flange k, so that on the
further rotation of the collar sufficient pressure is effected against the periphery of
the flange k to cause it to be gripped by the roller even if only one roller be so
confined at one time, and a corresponding movement is thereby conveyed to the
hub K. Motion in the reverse direction to that indicated by the arrows would
naturally tend to place the rollers Q in the extremities p of the recesses P, so that
frictional contact of the inclined faces of the recesses and the periphery of the hub
flange through such rollers would not tend thereby to be produced and no motion
therefore would be conveyed.
It will be understood that I do not claim to be entitled broadly to the means of
communicating motion as represented in Figure 7 and explained in the paragraph
immediately preceding and I do not limit my invention to the use thereof as I may
employ such equivalent means as a pawl and ratchet by which a positive though no
less certain movement may be made in one direction while no reverse movement is
conveyed by the return stroke of the pawl or other operating part.
The action of driving mechanism is as follows:-On the depression of the pedal
crank F the driving arm G is carried forward to a corresponding extent and the rope
or chain H is pulled in a forward direction. The collar I is thereby also rotated in the
direction indicated by the arrows and the driving impulse is conveyed to the hub of
the driving wheel by frictional contact of the rollers Q with the hub flange k as before
described. The return movement of the pedal crank is effected by the spiral spring N
previously coiled by the rotation of the collar I to which its outer end is secured, and
the pedal is brought to its upper position and ready again to be depressed.
It will be seen that the pedal crank F can be depressed to any extent and at any
rate required, and that the driving effort may be applied independently of any
periodicity of the pedal or rate of motion of the machine: a positive driving effort
being conveyed at any rate, time or extent as may be required: and as a pedal
crank and corresponding driving collar are independently mounted upon either side
of the machine, the pedals may be operated simultaneously or alternately as
rèquired.

page_text: In order to effect a variation of the leverage of the bell crank lever that is
formed by the pedal crank F and driving arm G I provide in one application, a
jointed extremity G to the arm G which is provided with protruding circular
hinge extremity 9. This hinge extremity g is formed with three flat facets xxx
against which the flat spring R may rest and which ensure the arm being held in either
of the positions a b c indicated in Figure 4. By such means I am readily enabled
to change the leverage while the extremity of the arm may yet be positively held
in either of the positions in which it may be placed.
It will be seen therefore that my driving gear may be arranged for communicating
any desired degree of driving effort and that the necessary alteration may be
instantly effected by the rider even when on the machine. This facility of adjustment
is especially convenient to riders having one limb weaker than the other and is
generally convenient for adjusting the driving effort to the direction or degree
of gradient.
It is obvious that I may use other means of varying the leverage of the bell crank
lever F G, such for instance as that illustrated in Figure 6, in which an adjusting
sleeve g² is shown screwed upon the arm G and connecting the extremity G¹ which
carries the end of the driving rope or chain. The sleeve g³ it will be seen is capable
of effecting the elongation of the arm by rotation in one direction after the lock nuts
have been unscrewed and any degree of leverage may thereby be fixed within limits
allowed by the screwed end of the arm G and the extremity G¹.
Stops S are arranged upon the bracket B to limit the upward and downward
movement of the pedal crank.
In another constructional modification of gear adapted to a velocipede of different
type to that illustrated I provide the pedal crank levers integral or connected with
the partially rotating collar 1, and thereby dispense with the driving rope or chain,
the other essential details of design being the same. In such case I may introduce
gear wheels to increase the speed of rotation.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. In velocipedes, the provision of driving gear consisting of a vibrating pedal crank
lever, a driving collar or lever connected to the extremity of the arm of the pedal
crank lever by means of a driving rope or chain, such collar or lever being arranged
in close proximity and in operative connection with the hub of the driving wheel, so
that on the depression of the pedal crank lever the forward rotation thereby imparted
to the driving collar or lever may be communicated to the hub, a spring for effecting
the return of the pedal crank lever to its upper position and means for rendering the
backward motion of the driving collar or lever ineffective and independent of the
reverse forward rotation of the hub, substantially as described.
2. In velocipedes, the provision of driving gear consisting of a vibrating pedal crauk
lever, arranged upon the axle of the driving wheel in close proximity and in operative
connection with the hub of the driving wheel so that on the depression of the pedal
crank lever a forward rotation is communicated to the hub, a spring for effecting the
return of the pedal crank lever to its upper position, and means for rendering the
backward motion of the boss of the bell crank lever ineffective and independent of
the reverse forward rotation of the hub, substantially as and for the purpose
described.
3. In driving gear for velocipedes as defined in the preceding claims, the means for
producing an effective forward rotation of the driving wheel, and an ineffective
backward rotation of the part communicating motion substantially as described.
4. In driving gear for velocipedes, as defined in the preceding claims, the means
for producing an effective forward rotation of the driving wheel, and an ineffective
backward rotation of the part communicating motion substantially as described and
illustrated in Figures 7, 8 and 9 of the drawings.
5. In driving gear for velocipedes as defined in the first claim, means for varying

page_text: the leverage of the pedal crank lever consisting in the provision of an adjustable
driving arm substantially as herein before described.
6. In driving gear for velocipedes as defined in the first claim, means for varying
the leverage of the pedal crank lever.consisting in the provision of an hinge extremity
of the driving arm to which the driving rope or chain is secured such hinge being
provided with facets in determined positions against which press a catch or spring
for positively retaining the extremity of the arm in different positions capable of being
readily changed substantially as and for the purpose herein before described.
7. In driving gear for velocipedes as defined in the first claim, means for varying
the leverage of the pedal crank lever substantially as described and illustrated with
reference to Figures 3, 4, 5, and 6 of the drawings.
8. The provision of driving gear for velocipedes and other purposes substantially
as herein before described.
9. In velocipedes the provision of driving gear substantially as and for the purposes
hereinbefore described and illustrated.
Deted this 15th low of Ontahan jac
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.