A New or Improved Driving Mechanism and Variable Speed Gear for Velocipedes, also Adaptable for other purposes.
Year: 1894

page_text: The decision of the Comptroller-General, of the 2nd day of April 1895, allowed,
under Section 18 of the Patents, &c. Act, 1883, an Amendment of this
Specification.
COMPLETE SPECIFICATION (AMENDED).
A New or Improved Driving Mechanism and Variable Speed Gear
for Velocipedes, also Adaptable for other purposes.
I, GEORGE DENNANT of 43 Victoria Street, Dovercourt, in the County of
Essex, Mechanical Draughtsman, 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 a new or improved mechanism to be applied to, or
employed in the construction of, bicycles, tricycles and similar manumotive machines
for the purpose of imparting motion thereto either by the weight of the rider alone,
or the pressure of his feet or both and in combination with a simple and easy means of
adjustment, to vary the speed or power of the machine at the expense of each other,
and at the will of the rider, and my invention has further for its object to overcome
dead centres by utilizing only that portion of the throw of the pedal cranks from
which is obtained the greatest leverage and power.
In order that my invention and the manner of its operation may be fully and
clearly understood I have hereunto appended two sheets of drawings, in which
Figs. 1, and 3 Sheet 1 are side elevation, front elevation and plan respectively
of so much of my improved driving mechanism as is necessary to make my inven-
tion understood, when described as hereinafter set forth, and arranged as prefer
it should be when applied to safety bicycles and other rear driven machines.
Fig. 4 is an outer view of the right hand end of the wheel hub according to one
method of construction according to my invention, and from which the outer or
enclosing plate has been removed.
Fig. 5 is a section of Fig. 4 upon the line AB, as viewed from left to right.
Figs. 6 and 7 are views illustrating an alternative method of construction and
arrangement of the driving mechanism I may adopt, the former of which is a
section upon the line CD of the latter, and viewed from right to left, while the
latter is a section upon the line E F of the former and viewed from left to right.
Figs. 8, 9, 10, 11, 12 and 13 Sheet 2 are diagrammatic views illustrating alter-
native methods of arranging the driving pads and variable speed gear according to
my invention, and which will be hereinafter fully explained.
Similar letters of reference are used throughout the drawings when indicating
the same or like parts.
In so far as relates to safety bicycles and other rear driven machines, for the
purposes
of my
invention I prefer to arrange the frame of the machine that the
equivalent for the usual back fork, takes the form shewn in the plan view Fig. 3,
or substantially so, and starting from the seat of the seat bearing standard A. and
back bone B, the frame or back fork C extends horizontally from each side thereof
for a suitable distance and is then bent or curved at a a and continuing backwards

page_text: ultimately carries the spindle D of the rear or driven wheel E, and between a a
and D, this may be further bent or curved in any suitable manner to accommodate
the form of speed gearing that may be employed.
At a suitable distance backward from the seat of A, the frame C is constructed
to carry loosely a pair of spindles bb, the inner ends of which have fixed thereon
a pair of bevel or mitre wheels c c', both of which gear with a similar wheel d
mounted loosely upon a fixed spindle carried by the base of A.
The hub of the back or driven wheel E is constructed in two parts F and F'.
exactly alike internally and externally, saving that their general arrangements are
in reverse order to each other, that both may operate as hereinafter explained, for
imparting a forward thrust to the wheel E, and bearing this in mind, a description
of the right half Fwill suffice, which I construct as follows.
Referring to Figs. 4 and 5 I cast or otherwise produce from any suitable metal or
metal alloy a case or box F, one side of which is entire and formed with a boss e, bore.
or otherwise to fit loosely upon the spindle D, the opposite side of F being open,
and through this a wooden or other solid block or pulley H is placed, fitting loosely
upon D, the portion of which outside F, has formed upon its circumferential
surface a spiral groove f, capable of receiving a rope, cord or chain, the
inner portion of H, having formed upon its circumferential surface a swelling H',
in which is provided a recess H, suitably shaped to receive the rounded
end of a pivoted clutch piece J, capable of oscillating for a suitable or
given distance witbin H", the length of J being such that when forced by the
tension of a spring g, fixed upon H, in the direction of the arrow Fig. 4, the
V shaped outer end of J would bite against the inner surface of the ✓ shaped
outer periphery G' of the case F, so that when motion was given to the block or
pulley H in the a direction of opposite to the arrow in Fig. 4, the end of J would
bite against G with sufficient force to carry round the case in the same direction,
and as this carries one half the number of spokes E' of the wheel E, and the counter.
part of Fig. 5 the other half (as shewn by F and F in Figs. 2 and 3), it follows.
that the motion imparted to these cases FF, would impart motion to the wheel E.
I may in some cases construct the periphery G' of the case F, of circular or
rectangular form in cross section, or with a V shaped groove in lieu of the V shaped
extension shown, in either of which cases the outer end of the clutch J would be
shaped to coincide therewith. The block or pulley H would be retained in position
within F by a closing plate h, screwed or otherwise fixed thereto, which would also
serve to keep out dust and dirt. The pivot pin i of the clutch piece J, would be
borne by the swelling H'.
As an alternative method I may arrange the driving mechanism in F. as shewn
in Figs. 6 and 7. In this device, I dispense with the swelling or extension H' and
recess H upon the inner end of the block, pulley or sheave H, and the clutch
piece J, and in lieu of these I screw or otherwise fix upon the inner end of Ha
ratchet wheel K, which may be of metal, or vulcanite fibre to deaden sound, and
engaging with K I provide three or more pawls K' also of metal or vulcanite fibre,
and pivotted upon pins K" borne by F and h, and the said pawls may be arranged
to engage with K by gravity or by the tension of suitable springs. The operation
of this device would be similar to that of Figs. 4 and 5, that is to say, if, by either
of the methods hereinafter explained, motion be imparted to the block or pulley H
and consequently the ratchet wheel K in the direction of the arrow Fig. 6, by
reason of this engaging with one or more of the pawls K' motion would be
imparted in the same direction to the case F' and the wheel E connected thereto.
Referring again to Figs. 1, 2 and 3. Upon the outer end of the mitre wheel
spindle 6 I mount a bell crank lever, which in this case consists of three
arms M, M and M" all radiating from a common centre M" keyed or otherwise
fixed upon the spindle b, and describing by their outer ends an equilateral triangle,
or approximately so, and upon the spindle b I mount in the same way an exactly
similar lever composed of arms N, N₁ and N" upon a common centre N. The
arms M and N constitute an equivalent for the usual pedal cranks, and the outer

page_text: ends of these are slotted for receiving and holding the bolts of the pedals M*
and N in the usual way. Suitable tie rods & connect the end of M with the ends
of M and M", and the end of N with the ends of N¹ and N", and if necessary
like rods may connect the ends of M¹ and M" and the ends of N' and N¹. The
outer ends of M¹ and M" also carry swivelled loops 7 and 1, and to 7 is connected
one end of a chain, cord, gut, wire or other rope or the like m, which passes
therefrom in a backward direction over, and twice or more around the spirally
grooved portion of the hub F', its opposite end being connected to the loop 1.
In like manner the arm N' carries a swivelled loop to which is connected one
end of a similar chain or the like m¹, which after passing in like manner around
the spiral groove f of F, is connected to a loop swivelled upon the end of the
arm N. Care must be exercised in fixing the said bell cranks upon their
respective spindles 661 that at the midway stroke of the cranks M and N the
pedals M and N' are level with each other, as at Fig. 2, and by reason of the two
cranks M and N being fixed upon the same spindles as are the mitre wheels c
nd c, and the latter both in gear with the mitre wheel d, it is obvious that as one
dal is depressed the other would be raised.
It will therefore be understood that if the rider when in his seat presses with
his feet or places his weight upon the right hand pedal M, this and the arm M
would be depressed thereby; and M' describing the same sector of a circle as M
would unwind a portion of the chain or the like m from ƒ of the pulley H of the
half hub F, and if this be constructed as at Figs. 4 and 5, the motion thus given
to H, would cause the clutch J to bite against the inner face of the periphery G¹
of F and force this round, and thus give motion to the wheel E, and the impulse
thereby given to the machine would cause E to continue to revolve for a short time
after the pedal M had reached its lowest position, when the stoppage of the
rotation of the pulley H would cause the clutch J to cease to bite against G¹, and
permit this to pass idly by during the return or upstroke of M. The sector of a
circle described by M¹ would also be made by the arm M", so that while the
former was unwinding one end of the chain or the like m from f, the opposite end
of same would be wound thereon by the movement of M" and vice versa when M
was again raised.
The same motion would be imparted to E by the depression of M' if the hub be
constructed as at Figs. 6 and 7, (these being shewn arranged for F¹) by reason of
the ratchet wheel K fixed upon H engaging with one or more of the pawls K',
pivotted at K" upon the case F, and plate h.
When the pedal M was fully depressed the pedal N* would be in its highest
position, and the rider would then transfer his weight or pressure from the former
to the latter, and by depressing this give further motion to the wheel E by
reason of the arm N' unwinding m³ from f of the half hub F', which as before
explained would raise the pedal M by the operation of the gear e c² and d.
may, if desirable, dispense with the spiral groove f on the pulleys or sheaves H,
and in lieu thereof fix upon each of said pulleys a sprocket wheel, and employ,
chains m and m' capable of engaging therewith.
The foregoing description and the drawings on Sheet 1 serve to make clear that
part of my invention which relates to the propulsion of the machine, and it will be
casily understood by any person skilled in the manufacture of velocipedes, that a
very slight modification of the foregoing will adapt the mechanism to the propulsion
of tricycles, tandem bicycles, and other like machines, and that the same principle
may be employed in giving motion to many forms of other machinery, in which the
vertical motion of a lever, such as M, may impart a rotary motion to a shaft such
as D, and a fly wheel such as E.
The diagrams in Sheet 2 (excepting Fig. 11) serve to illustrate the principle of
that part of my invention which relates to variable speed and power.
Referring to Fig. 8 Sheet. 2. According to this arrangement, the arms M', M
and N' Nu are curved to coincide with the radius of the wheel E, and upon these
are placed sliding collars n n', which receive the ends of the chains or the like m
:

page_text: and m¹ and upon the pedal arms M and N I provide similar sliding collars "
.connected by rods o and o¹ to the collars n n². By moving the collars n" nearer to
the pedals the collars n n' would be brought nearer to the axis of the pedal
cranks, thus increasing power at the expense of the speed of the machine, the
reverse movement of a n¹ and n" having a directly opposite effect. The collars n
may be arranged to be operated by the feet of the rider. This arrangement of the
sliding collars may also be employed when the arms M' M" N' and N are straight
as at Fig. 1.
In the arrangement shewn by Fig. 9 the arms M' and N¹ and the cranks M
and N only, are employed, the arms M" and N₁ being omitted, and in lieu of these
an elastic substance or spiral springs P is employed, the tensions of which operate
to effect the return motion of the pulleys H on F and F. The arms M' and N¹
in this device are curved in the opposite direction to those in Fig. 8, and sliding
collars n and n may be also employed in this arrangement for the same purpose.
In Fig. 10 I illustrate a similar arrangement, saving that in this case the arms M'
and N are straight and telescopic, the lengthening or shortening of which in
conjunction, may be, with a collar n" regulate the power or speed of the machine.
Fig. 12 shows an arrangement similar in effect to that of Fig. 8, saving that, in
this case, the arms M1 and M1 are in one piece, as also are N¹ and N", and are
placed at a different angle relatively to M and N, and arranged to slide within the
centre pieces M and N and be fixed in any position therein by a fly nut bolt or
its equivalent R, speed or power being obtained by shortening or lengthening M¹
and N¹.
In Fig. 13 I illustrate an arrangement in which the arms M¹ M" and N₁ N",
and the sliding collars n and n¹ thereon are identical with Fig. 8, the collar n" being
absent, and in effect, I provide its equivalent by forming slots S in the arms M
and N arranged to slide upon the centre pieces M and N, and be fixed thereon
at any portion of the length of S by a fly nut or its equivalent R. Therefore, when
power is required n and n' would be brought nearer together, and the cranks M
and N be lengthened, and the reverse of this when speed was wanted.
In Fig. 11 I show another arrangement. In this device the cranks M and N
would be pivotted upon lugs depending from the axle of E or the frame of the
machine and upon the half hub F one end of the chain or the like m, would be
fixed by any suitable means to the pulley H, from which it would be led under
and over a loose pulley or grooved wheel I mounted upon the frame of the machine,
and its opposite end be connected to the pedal end of M. Upon the opposite side
of the machine, one end of the chain or the like m¹ would be in like manner
connected to the pulley H of the half hub F, from which it would be led over the
same pulley or grooved wheel T upon the frame of the machine, its opposite end
being connected to the pedal end of N. It will therefore be seen that the
depression of the crank M would revolve the pulley T in the direction of the
arrow, which would raise the crank N, and that the depression of N would
revolve T in the opposite direction and raise the crank M and so on ad lib. To
effect the return motion of the pulleys H I connect to each lug r an arm t, to the
ends of which are connected one end of elastic or spring governed cords w which
pass therefrom and are wound once or more around the pulleys H, and these cords
becoming elongated during the depression of their respective cranks M and N,
their tension would effect the return motion of the pulleys H when the pedals were
raised. This arrangement does not apply for any variation of speed or power, but
is an alternative method of propelling the machine.
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.
1st. In the manufacture of bicycles, tricycles and similar manumotive machines,
the construction and use of any and all of the mechanical devices herein described,
or any desired combination thereof and the application of same for the propulsion

page_text: of such vehicles, operated by the weight of or pressure from the rider or riders
only, or and for varying the speed and power of same, connected together and
operating substantially as herein described and shewn by the accompanying
drawings.
Or the
2nd. In the manufacture of bicycles, tricycles and similar machines, the
construction use and application of the herein described mechanism for propelling
the same by the weight of or pressure from the rider or riders ealy, consisting of
a fork C. connected to or forming part of the frame of the machine, and carrying
the spindle D of the rear or driven wheel E, the hub of which is in two parts
and constructed as at Figs. 4 and 5 or substantially so, consisting of outer
cases F F together carrying the spokes E' of the wheel E, and each containing,
in reverse order to each other, a block or pulley H retained therein by a plate /
having upon their exposed circumferential surfaces spiral grooves f, or carrying
sprocket wheels in lieu thereof, and at their inner ends provided with a swelling H
in which is formed an aperture H" for receiving and holding a clutch piece or
clutch pieces J pivotted at i, the free ends of which engage with the inner
surface of the periphery G₁ of F and F', by the tension of a spring o
hubs or half bubs F F' may be constructed as at Figs. 6 and 7, in which the inner
end of H carries a ratchet wheel K, engaging with pawls K', pivotted upon
pins K borne by F or F¹ and h. The mitre wheel borne by the fork or
frame C, and gearing with mitre wheels c and c¹, carried upon the inner ends of
spindles 66, the outer end of the latter of which carries a bell crank consisting of
arms M' and M", and pedal crank M, connected at the free ends by stay rods k,
the said arms carrying the ends of chains, cords, ropes or the like m, wound upon
the spiral groove f of H in F, or engaging with a sprocket wheel thereon, the
outer end of the spindle 6 carrying a like bell crank consisting of arms N¹ and Nu
and pedal crank N, connected by tie rods k, and carrying in like manner a chain
or the like m¹ engaging in the same way with H of F, the whole connected,
combined and operating substantially as and for the purposes herein described and
shewn by the several views upon Sheet 1 of the accompanying drawings.
b
3rd. In combination with the principle portion of the mechanism set forth in the
preceding claim, and as an alternative method of and means for operating the same,
the construction and use of pedal cranks M and N, pivotted upon lugs r borne by
the axle D or the frame of the machine, to the pedal end of the former of which is
connected one end of a chain, cord or the like m, which is led therefrom under and
over a pulley or wheel T, and connected to H of F, the pedal N carrying in like
manner a chain or the like m¹ passing over T and connected to H of F, the return
motion of the blocks H being effected by cords w and arms t substantially as
herein described and shewn by the accompanying drawings, especially by that of
Fig. 11.
4th. In combination with the principle portion of the mechanism set forth in the
two preceding claims, and operating therewith for effecting the alternate use of
variable speed and power, the construction and use of any and all of the several
methods and means for effecting this, or any desired combination thereof,
substantially as herein described and shewn by Figs. 8, 9, 10, 12 and 13 of the
accompanying drawings.
Dhokh dan of Armand 1801