Improvements in Means for Propelling Bicycles and Analogous Vehicles.
Year: 1897

page_text: Date of Application, 20th July, 1897-Accepted, 4th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in Means for Propelling Bicycles and Analogous
Vehicles.
We, FRANCIS WILLIAM MALLETT, of 970 Amsterdam Avenue, Engineer, and
WILLIAM AUGUSTUS HULBERT, of 125 East 57th Street, Manufacturer, both
residents of New York City, in the County and State of New York, United States
of America, do hereby declare the nature of our invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by.
the following statement:-
The best means for transmitting power from the crank-shaft to the rear or
driving wheel is perhaps the most important mechanical problem offered in bicycle
construction. While the sprocket-chain so generally employed has an advantage
in its simplicity and directness it is open to many objections; it is exposed to the
dust, often fine sharp sand, which mixing with the lubricant, produces an abrading
paste entering each of the many joints, rapidly cutting away the chain and
sprocket-wheels. Attempts have before been made to incase the chain, and also
to avoid its use by the substitution of beveled gearing and countershafts, also
incased, but in all the forms known to me the result is a cumbersome, unbalanced
and unsightly addition to the wheel.
The object of our invention is to provide means for transmitting the power
directly while avoiding the use of chains or gearing, and also to inclose the
mechanism almost entirely within the frame of the machine, thus effectually
excluding the dust and still retaining the appearance of lightness which is one of
the chief beauties of the bicycle.
The invention consists of thrust-rods inclosed within the tubular members
forming the lower rear fork, actuated longitudinally by spurs or projections on
driving wheels turning with the crank-shaft and giving corresponding successive
impulses to the rear wheel of the bicycle. The power is communicated to 'the
rear wheel by a clutch mechanism acting in the direction to drive the bicycle
forward, returning idly, and the spur-wheels are so set on the crank-shaft that
their teeth alternate, insuring that one thrust-rod and its connections is always
engaged and in position for effective work.
We supply means for preventing the spur-wheels turning in the wrong direction
and also a simple and efficient brake mechanism. All the working parts not lying
within the frame are inclosed in dust-proof casings.
The accompanying drawings form a part of this specification and represent what
we consider the best means of carrying out the invention.
Figure 1 is a side elevation on a small scale, showing a bicycle constructed in
accordance with our invention. The remaining figures are on a larger scale.
Figure 2 is a vertical section partly in elevation showing the main working parts.
Figure 3 is a corresponding horizontal section and plan view. Figure is on a
still larger scale; it corresponds to a portion of Figure 2 but shows the parts
more completely and also differently conditioned. Figure 5 is a horizontal section
through the upper member of the bicycle frame and a portion of the upper rear

page_text: fork. Figure 6 is a corresponding vertical section of a portion. Figure 7 is a
vertical section showing a detail on a much larger scale.
Similar letters of reference indicate the same parts in all the figures.
A is the bicycle frame, certain portions being designated when necessary by
supernumerals as A¹, A2. B and B refer respectively to the rear and front
wheels, B is the saddle, B³ the pedals and‍ 33* the handle-bars, all of any well
known or approved construction, except as hereinafter stated.
C is the crank-shaft turning in ball bearings as indicated at b. C, C¹ are
wheels or spider frames carrying spurs 2 on their peripheries having rounded
or semicircular ends matching closely to the correspondingly shaped interior of
the casing A¹; each spur-wheel C₁ is grooved on its periphery between the spurs
so that the faces of the latter show and fill true circles formed half by the casing A'
and half by the groove; the back face of each tooth curves downward on a concave
line to the periphery. The radial arms C³ are set at one side of the centre of the
wheel to provide space within the casing A¹ for an annular flange (fixed on the
arms about midway between the hub and periphery, its outer face is turned true
and against it lies a brake-shoe C connected by a loose link C to a fixed pin a
set in the casing; a¹ is a fixed stop projecting inward from the latter and a² is
a thrusting spring tending to force the shoe backward; so long as the spur-
wheel C turns in the direction indicated by the arrow to propel the bicycle.
forward the shoe is inoperative and rides idly on the flange C but iinmediately
resists any attempt to turn in the opposite direction by straightening the toggle
formed by the link and shoe and tightly holds the wheel against the reverse
motion.
. D is one of a pair of transmitters or thrust-rods, one in each member A2 of the
nearly horizontal rear fork of the frame; the stiff central portion is smaller than
the interior of the member and is guided therein by the bushings a³ and the
.collar d, the ends D1, D2 are flexible, being formed of steel wire closely coiled in
a manner analogous to a helical spring but with each convolution in contact with
the next; this construction allows all the flexibility required with no compressi-
bility longitudinally, qualities of vital importance to the successful operation of our
invention. The end D' is guided in the smoothly curved extensions A³ of the
casing A¹ and also by a series of rollers a mounted on fixed studs supported in the
casing; at the extremity is a hardened steel button D3 having a hemispherical face
and a shank spirally grooved or screw threaded to match to the coils of the wire
and held therein against withdrawal by soldering or brazing, the function of the
button is to contact with the spurs C2 on the spur-wheel C¹ as they are successively
presented and transmit the power received to the thrust-rod of which it is a
part.
D is a spiral thrusting spring lying between the bushing a³ and collar d,
exerting its force to impel the rod. D toward the spur-wheel and force the button D³
into the path of the succeeding tooth or spur after each impulse, and D5 is a
similar but lighter spring interposed between the collar d and the bushing a to
cushion the rod on its release from a spur and prevent undue shock or noise.
The opposite end 12 of the rod is similarly formed and guided in the extension A³
of the casing A by the rollers a; the button 16 at this end is knuckled to a
pin F3 projecting from a block F2 forming part of the clutch mechanism inclosed
in the casing A¹.
The construction and arrangement of the lower rear fork is important, each
member A2 is smoothly finished on its interior and is joined to the extension A³
by a socket on the latter large enough to receive the exterior of the tube A² and
preserve a smooth unbroken joint on the interior so that the flexible portion I)¹
of the thrust-rod D. may reciprocate across the junction freely and with little
friction. The construction at the opposite end of the tube A³ is correspondingly
made to facilitate the transverse of the portion D2 of the rod, from the tube to the
interior of the extension A5.
E is the fixed rear axle of the bicycle, its central portion is cylindrical, the

page_text: ends Ebeing flattened to engage correspondingly shaped slots in the casing to
prevent rotation and held in place by the nuts on the screw-threaded exten-
sions E; the hub of the rear wheel B revolves on the cylindrical portion and
consists of a tubular portion E matching to the axle and two radial flanges E5 to
which are attached the wire spokes of the wheel in any ordinary or approved
manner; the outer face of each flange carries an annular flange E matching
closely to the inclosing casing A+ and forming an important part of the clutch
mechanism. E' are collars matching the axle and screwed into the outer faces of
the flanges E to form extensions of the tubular portion and each carries in an
enlargement E8 the anti-friction balls for the bearings. Fitted upon the neck
portions of each of the collars E7 and held therein by the enlargements E8 is a
loose ring F having a spring arm F¹ formed in one therewith or otherwise
secured thereto, extending radially and terminating in the head or block F2 before
mentioned, curved on the outer face to match to the inner face of the annular
flange E, lying closely thereto and knuckled as above described to the button Do
and moving with the rod D. A segmental clutch-block F5 is connected to the
ring F by a short angularly arranged toggle-link F adapted when straightened to
force. the clutch-block into strong frictional contact with the inner face of the
flange E
It lies with its rear face adjacent to but slightly separated from the front face
of the block F². A spring F interposed between the link F and a stop F8 fixed
on the casing-flange F7 forming part of the block F2, exerts a force tending to
push the clutch-block rearward or toward the block F
When the thrust is received from the rod D, D¹, D³ the first effect is to push the
block F2 forward and slightly deflect the arm F¹, the latter in yielding imparts
its motion to the ring F causing it to turn on the collar E' and straighten the
toggle-link F, this engages the clutch-block strongly with the flange E and
turns it and the rear wheel B. The space between the block F2 and the clutch-
block is so slight that the former will contact with the latter before the strain on
the spring arm F1 is sufficient to endanger it and all the parts of the clutch
mechanism are so nicely fitted to each other that the lost motion is reduced to a
minimum. The yielding of the spring-arm F¹ performs an important function in
the operation of the clutch by preventing the clutch-block F3 engaging the
flange E too strongly; if the arm were rigid the full force of the thrust received
from the rod D would be communicated to the toggle, and as the force varies with
the power exerted by the rider there would be liability of the toggle under great
pressure assuming a nearly straight position and refusing to again release. This
is avoided by the elasticity of the spring-arm by transferring to the toggle only
that amount of pressure necessary to effect the engagement of the clutch-block
with the flange and if there be any surplus, to then bend the arm until its block F2
advances to and against the adjacent face of the clutch-block, any further pressure
is then received directly upon the clutch-block in the direction to release. The
result, if the parts be properly proportioned, is to cause the toggle to straighten
to a certain angle and engage the flange E with proportional force regardless of
any excess of thrust, such excess instead of breaking or deranging the parts being
expended in slipping the block F5 on the flange.
As before stated one of the clutches is always in engagement while the other is
returning idly and as the return movement is made in much less time than the
thrust, both clutches will be engaged at the same time during a portion of each
stroke or reciprocation of the rod. Each complete revolution of the crank-shaft C
produces seven impulses in the rod which are transmitted to the clutch mechanism
on each side and the ratio between the spur wheel and clutch as here shown will
produce a little over two turns of the rear wheel for each revolution of the
crank-shaft; this proportion may be varied to produce any required ratio.
A is a fixed stop secured to the casing A* and projecting into the path of the
clutch-block F5 a little in advance of its extreme throw, and G is a thin wedge

page_text: pivoted to one end of a bell-crank lever G¹ with liberty to swing through a small
arc; the other end of the bell-crank is knuckled to a rod G³. There are preferably
two sets of this mechanism, one for each clutch; each rod G2 is inclosed in a
member of the upper rear fork and extends upward therein. These members are
joined to each other by a semicircular curve partially encircling the seat post set
in the bracket A7 and both join the upper straight member A8 of the bicycle
frame. The upper ends of the rods G2 are flexible similar to the ends of the
rods D, and the flexible portions G³ join a single stiff straight rod G inclosed in
the member A8 and knuckled at the end to a lever G5 fulcrummed at g and working
fore and aft in a slot A, the latter is notched at each end as shown to retain the
lever at either end of its throw while allowing it to be readily released and moved
in the slot. This train of mechanism constitutes the brake; by turning the
lever Grearward each wedge G is projected outward into the space between the
front face of the clutch-block and the stop A6, preventing further travel
of the clutch-block and partially releasing its hold on the flange E6, thus
conditioned the force with which the clutch-block will engage the flange
depends upon the force transmitted through the thrust-rods and increases
with the pressure exerted by the feet on the pedals until the block F2 is forced
tightly against the rear face of the thrust-block, this is sufficient to quickly slow
down the bicycle but as the latter is going too fast the flange E6 is moving in the
same direction as the clutch-block ordinarily tries to send it, so the flange moves
past the block in opposition to the friction of the latter but in the direction to
diminish such friction by the tendency to increase or widen the angle of the toggle
and thus avoid instantaneous and dangerous stopping.
Each
pur
Con the
rearward and
The operation of the driving mechanism is as follows:-The pedals are placed
in position as desired by the rider and as they are not positively connected to the
rear wheel they remain in that position while the rider mounts and places his feet
upon them, he then revolves the pedal shaft as usual.
wheels C as it comes in contact with the button D3 forces the rod
through the clutch mechanism revolves the rear wheel, as soon as the spur passes
the button the rod returns and receives a fresh impulse from the next spur, as
before stated the spurs alternate on the wheels so that one thrust-rod is always
engaged and is exerting its force to drive the bicycle forward. In coasting, the
feet are not removed from the pedals and the thrust-rods remain stationary, the
bicycle travelling with no impediment other than the friction of the wheels on
the ball bearings. If the speed becomes too high the rider checks it by applying
the brake, the speed may then be regulated by pressure on the pedals in the
direction to drive the bicycle faster.
The working faces of the teeth C2 are curved as shown in Figure 2 to leave.
the buttons D with a wiping motion to avoid the danger of jamming the buttons
between the faces of the spurs and the rollers a, and the rear faces are concaved
to allow the immediate return of the rod 1 by the expansion of the spring D* after
the passage of a spur. Reverse motion of the spur-wheel would crush the flexible
end of the rod and is prevented by the shoe C³ and its connections.
Each impulse given by a tooth or spur C2 to the rod D is transmitted directly
to the rear wheel, the only loss of power being that due to the friction in turning
the slight curves.
All the parts are inclosed within the framing or in dust proof casings. The
weight of the driving mechanism is we believe less than that of the ordinary chain
and its connections. The driving action is positive and is exerted on both sides,
avoiding in great measure the torsional strains due to gearing on one side of the
bicycle. Another advantage lies in the fact that the rider cannot loose his pedals;
in coasting, his feet may remain idly upon them, or in case he removes his feet
the pedals do not partake of the rotation but stand ready to be again engaged.
Modifications may be made in the forms and proportions and in the details of
construction within wide limits.

page_text: Other forms of clutch mechanism may be substituted for that shown, and the
brake mechanism may be omitted or other known or approved form applied.
Although the invention has been described as applied to bicycles, it will be
understood that it may serve in any analogous vehicles.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what we
claim is:
-
1. In a bicycle, a spur driving wheel, a flexible thrust-rod adapted to follow
the curves in the inclosing frame-members and casings, held yieldingly with
one end in the path of the spurs and reciprocated by the passage of the latter, in
combination with said frame-members and casings and with a clutch engaging
the rear wheel of the bicycle and operated by the reciprocations of said rod, all
substantially as herein specified.
2. In a bicycle, a spur driving wheel, a thrust-rod reciprocated by the passage
of the spurs and having an inflexible middle portion and flexible ends adapted
to follow the curves in the inclosing frame-members and casings, in combination
with the latter and with guide rollers arranged at such curves on the opposite
side of the rod to prevent buckling of said ends, and a clutch engaging the rear
wheel of the bicycle and operated to drive the latter by the reciprocations of said
rod, all arranged to serve substantially as herein specified.
3. In a bicycle, the thrust-rods D, D1, D2 inclosed within the members of the
lower rear fork, the bushings a³ and a³ therein, the collars d on said rods, the
springs D and cushion springs D5 arranged between said collars and bushings,
the spur driving wheel C₁ for reciprocating said rods, and the clutch mechanism
engaging the rear wheel of the bicycle, all combined and arranged to serve
substantially as herein specified.
4. In a bicycle, the thrust-rods having flexible middle portions D and flexible
ends D1, D2 inclosed within the lower rear fork members, the bushings a³ therein
and collars d on the rods, the wheels C and spurs C2 thereon, the springs D
forcing one end of each rod into the path of the spurs, clutch mechanisms engaging
the rear wheel of the bicycle, and the flanges C on said spur-wheels and the
brake-shoes C, fixed stops a¹ and springs a² for engaging said flanges to prevent
reversing the direction of motion of the spur-wheels, all combined and arranged
to serve substantially as herein specified.
5. The clutch described consisting of a loose ring encircling the shaft on which
the rear wheel turns, a spring-arm extending radially from the ring, a clutch-block,
a link connecting the latter to the ring to form a toggle, and an annular flange on
said rear wheel engaged by said clutch-block when the toggle straightens by
pressure applied to said spring arm, all combined and arranged to serve substantially
as herein specified.
6. In a bicycle, the loose ring F encircling the shaft on which the rear wheel
turns, a spring-arm F1, F2 extending radially therefrom, and connections to the
reciprocating thrust-rod D, D1, D2, the clutch-block F5, the link F connecting
the latter to the ring to form a toggle, an annular flange E on said rear wheel fric-
tionally engaged by said clutch-block when the toggle straightens, the casing-
flange F7 and the spring Fe interposed between the latter and the clutch-block, all
combined and arranged to serve substantially as herein specified.
7. In a bicycle, the loose ring F encircling the shaft on which the rear wheel
turns, a spring-arm F1, F2 extending radially therefrom and connected to the
reciprocating thrust-rod D, D' D2, the clutch-block F³, the link F connecting
the latter to the ring to form a toggle, an annular flange E6 on the said rear.
wheel engaged frictionally by said clutch-block when the toggle straightens, in
combination with each other and a stop fixed to the casing in advance of the
throw of the clutch-block, a lever and a wedge thereon adapted to be thrust
between said stop and clutch-block, and means for operating the lever, all arranged
to serve substantially as and for the purposes herein specified.

page_text: 23612
"
8. In a bicycle, the loose ring F encircling the shaft on which the rear wheel
turns, a spring-arm F1, F2 extending radially therefrom and connected to the
reciprocating thrust-rod D, D1, D2, the clutch-block-F5, the link F connecting
the latter to the ring to form a toggle, an annular flange E6 on the said rear
wheel engaged frictionally by said clutch-block when the toggle straightens, the
stop A fixed on the casing in advance of the throw of the clutch-block, the
bell-crank lever G₁ and wedge G thereon, the rod G2 inclosed within a member
of the upper rear fork, the rod G inclosed within the upper member of the frame,
the flexible portion G³ joining the said rods, and the operating lever G5 pivoted
in said upper member, all combined and arranged to serve substantially as herein
specified.
9. In a bicycle, the driving spur-wheels and flexible reciprocating thrust-rods,
clutches operated by the latter and engaging the rear wheel of the bicycle, in
combination with the casings A¹ and A4 inclosing said spur-wheels and clutches,
and the tubular lower fork members A2 inclosing and guiding said rods, all sub-
stantially as herein specified..
10. In a bicycle, the driving spur-wheels, the flexible reciprocating thrust-rods,
and clutches operated by the latter and engaging the rear wheel of the bicycle,
in combination with the casings A¹ and A inclosing and guiding said rods, the
upper rear fork members and upper tube A8, and the brake operating rods inclosed
and guided therein, all arranged to serve substantially as and for the purposes
herein specified.
Data: 101 1
TI
1007
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62 Saint Vincent Street, Glasgow, Agents for the Applicants.