Improvements in the Frames and Driving Mechanism of Bicycles and the like.
Year: 1898

page_text: Date of Application, 5th Dec., 1898-Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
Improvements in the Frames and Driving Mechanism of Bicycles
and the like.
I, WILLIAM JAMES THOMPSON, of Warialda Street, West Kogarah, near Sydney,
in the Colony of New South Wales, Civil Engineer, do hereby declare the nature
of my invention and in what, manner the same is to be performed to be particu-
larly described and ascertained in and by the following statement:―
This invention relates to certain improvements in the frames and driving
mechanism of bicycles and the like whereby the hanger bracket and the inter-
mediate driving spindle are dispensed with there being substituted therefor
pedal levers (with approximately reciprocating motion) connected to cranks
revolving the axle of the driving wheel and having varying fulcra adjacent to
and relatively behind said axle from which axle multiplying gear imparts revolu
tion to said wheel.
But in order that this invention may be clearly understood reference will now
be made to the drawings herewith in which Figure 1 is a side elevation of a
bicycle akin to what is known as a safety bicycle constructed according to the
present improvements. Figures 2 and 3 are side elevation and plan partially in
section on a larger scale respectively of the driving mechanism of said bicycle.
Figure 4 is a similar view to Figure 3 of a modified construction of said driving
mechanism. Figure 5 is an elevation of toothed gear wheels and Figures 67
and 8 are plan and sections respectively of a pneumatic pedal.
The bicycle frame is preferably an adaptation of the diamond frame having
front fork a over the front wheel A, a backbone b, a diagonal or saddle pillar c,
two back forks d and e over the back wheel B, and a crosspiece or bearer f the
back end of which forms a bottom fork or brace f¹. With the exception of the
frame and the pedal-driving mechanism hereinafter particularly described all the
parts of the bicycle are of constructions well understood.
The axle B of the driving wheel B is carried in brackets or hangers C affixed
on bottom fork f' and the bearings it has therein are ball bearings Be the balls of
which may be adjusted or tightened in their race (or two half-cups) C by the
set-screws C in the bottom cover or half bracket C which is fastened by bolts C
to the fixed bracket C. C is an oil passage and Can oil pipe from the hub oil
The driving wheel B revolves on ball bearings 13 against fixed and movable
cones adjusted as well understood the gear side one being rendered dustproof
and oil-retaining by a guard or flange G³ on the clamp or nut L and the other one
by a cover L³.
саве.
The pedals I preferably of the kind hereinafter particularly described are on
levers D which have ball bearing joints 12 as shown to cranks B on ends of
axle B. Backwardly of this joint 12 each lever carries rollers or fulcra wheels E
and F on ball bearings D and D' respectively. Each fulcra wheel E is adapted
at certain parts of the stroke of the lever D to have bearing against guides or
grooves E affixed to the bottom fork fl the configuration of which guide or
groove is preferably as shown though it may be of other curved shape. Each

page_text: fulcra wheel F has bearing upwardly against straight guide or groove F1 under
the bottom fork f¹ though this guide may be of other form than straight. F¹ is a
guard for preventing the back end of lever D¹ from dropping. As the guides E
and Fact as the fulcra in different parts of the stroke of the lever D their
shapes or configurations are independent of one another though in practical work-
ing it is desirable that they be so constructed (say as illustrated in the drawing)
that the impact of the roller or wheels E and F on their respective guides will
take place smoothly and without shock. The rollers or wheels if necessary may
be covered with rubber or the like to destroy or diminish noise. In the drawing
the pedal lever D₁ nearest the observer is shown at its lowermost position while
the other lever is at the top of the stroke the position of the cranks B being
marked respectively as 1 and 3 on their circle of travel (dotted lines). As shown
the rollers and F on the nearer side are at points 1e and 1f respectively and
those on the other side at points 3e and 3 f. In dotted lines the positions of the
levers and rollers are indicated when the cranks B are at points 2 and 4 and 5
respectively the positions of the centres of rollers E and F being marked as 2 e 4 e
and 5e and 2f 4f and 5f respectively the full course of the centres of rollers or
wheels E and F being shown by dotted lines.
It will be seen from Figure 2 that the wheel or roller E leaves the guide E¹
when the pedal has passed through the greater part of the down stroke and again
engages with said guide E¹ at a very acute angle on the up or back stroke thereby
causing the impact to be unnoticeable and in a sufficient manner to just relieve
the wheel F from the guide F" until it is again about to leave the guide E¹ on
the down stroke of the pedal when wheel F again bears on guide F" thus giving
great power through the top part of the up stroke (for back pedalling) and the
greater part of the down stroke while roller F enables the foot to be carried back
through the remainder of the revolution and so on. If desired extending down-
wardly from the frame in front of the cranks B there may be guides for the
pedál levers to work in. The pedals D are attached to the levers D¹ by means of
clamp D and screw bolt and nut D₁ so that they may be set in any required
position along the levers. An additional or auxiliary pedal D may be attached-
to each lever so as to enable long or short leg strokes to be given if desired. The
pedals are hinged or jointed on pin 15 so as to have a slight oscillating motion
to adapt them to the position of the foot. The pedals are set on acute vibration
springs or as hereinafter described have pneumatic threads.
In the modification illustrated in Figure 4 there is but one back fork d and
the bottom fork f terminates just behind the brackets or hangers C (constructed
with ball bearings for the axle B as hereinbefore described). Instead of being
connected direct with the crank B the pedal lever D₁ carries on its ball bearing
joint D a bell crank D one end of which is connected to said crank B* while
the other carries on ball bearing D³ a roller or wheel E in guide E¹ while on
the roller bearing joint D' of said lever D is roller or wheel F in guide F¹. The
guides E and may be of any approved configuration having in view the easy
and smooth working of the levers D1 on varying fulcra and they are made in one
piece and clamped to the forks d and f¹. Similarly as hereinbefore described
each fulcra wheel or roller E as likewise its complement the fulcra wheel or
roller F is adapted at certain parts of its travel to have bearing against its guide
and at other parts to be relieved therefrom. In the drawings the cranks and
rollers and bell crank are shown in full lines as when at the top and bottom of
the stroke the crank B being in positions 1 and 3 on its circle of travel the
rollers E and F being correspondingly and respectively at le and 3e and
1f and 3f. Further positions as when the cranks are at points 2 and 4 are also
shown. The rollers E and F are correspondingly at points 2 e and 4 e and 2 f and 4 f
on their respective centre lines of travel. The corresponding positions of the
joint D are marked 1 d 2d 3d and 4 d respectively.
Whether the gear shown in Figure 2 or the mdification thereof shown in
Figure 4 be used it will be seen that a full stroke of the two levers D₁ (that is

page_text: one movement up and one movement down of each lever) will turn the axle B¹
in its bearings a complete revolution and continuous strokes will cause it to
revolve evenly at a comparatively good speed. But to increase the "gear" of the
bicycle the revolution of the axle B is multiplied while it is being imparted to
the driving wheel B and this is effected by tooth or chain or other convenient
gearing contained in a casing G attached by clips G¹ to the frame of the bicycle.
In this casing is a pin H with double cones H¹ forming ball bearings H for the
hub or boss of a double gear wheel or a double chain wheel. This pin H is held
on the sides of the casing G having slots or openings to allow it to be moved
either towards or from the axle B and hub B* for adjustment by means of sliding
pieces H³ on bolt H having nuts H³.
The larger driver wheel J has epicycloidal teeth and it is rivetted or bolted or
screwed to flange B5 on the axle B. This wheel drives the pin wheel K' rivetted
screwed or bolted to the boss or revolving piece K on ball bearings H2 on the
pin H. The toothed wheel K2 is also fixed to said boss K and it engages with a
driven wheel L' secured to the hub B by a left hand screwed circular clamp or
nut L and formed of rollers L between side pieces or cheeks L² or centre piece L³.
The wheel K is equal and similar to wheel L¹ also the wheels J and K2 are equal
and similar having the depressions or seating of the teeth cut deeper than the
radius of the roller teeth below the pitch circle and narrower than the diameter
of the rollers towards the bottom or base of the teeth to provide for adjustment
(consequent upon wear) which is achieved by bringing the wheels K' and K² with
the pin H closer to the axle B by means of the adjusting screws H. Through
this gearing the motion of the cranks B and axle B¹ is communicated to the
driving wheel B of the machine by the wheels J and K¹ through the wheels K³
and L but accelerated in the proportion to the diameters of wheels J and K² over
the wheels K' and L¹.
Instead the toothed wheels and pin wheels as described chain gearing might
be used in which case the double coned pin H would be the same but for the
wheels J and L and K and K sprocket wheels would be substituted short chains
passing around each driver and driven and adapted to be adjusted by screws H*
while the whole might or might not be enclosed in the dust proof casing G or may
be attached by clips inside or outside of the bicyclo frame.
The pneumatic pedal D consists of a tread M honey-combed or roughened on
its ends with side guards M¹ on top of a leather or rubber box or outer casing N.
This outer casing № containing an inner rubber tube O sits on a bottom plate P
with end flanges P₁ taking upwardly to the guards M¹ from which pins M² pro-
trude through slots P2. It will be seen that when the inner tube O is filled with
air under pressure (through ordinary ingress valve N¹) that the tread M will be
supported by such air pressure and thus the foot be pneumatically supported and
defended from jars or shocks.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
First Improvements in the frames and driving mechanism of bicycles and
the like consisting essentially of the combination of a crank on the axle of the
driving wheel of pedal levers connected to said cranks and having varying fulcra
adjacent to and relatively behind said axle substantially as and for the purposes
herein described.
Second A bicycle or the like having a frame and improved driving mechanism
substantially as herein described and explained and as illustrated in Figures 12
and 3 of the drawings.
Third A bicycle or the like having a frame and improved driving mechanism
substantially as herein described and explained and as illustrated in Figure 4 of
the drawings.
Fourth In a bicycle and the like having a frame and improved driving

page_text: mechanism as set forth the combination with reciprocating pedal levers of pneu-
matic treads combined and arranged substantially as herein described and
explained and as illustrated in Figures 67 and 8 of the drawings.
Dated this Twenty-seventh day of October, One thousand eight hundred
and ninety-eight.
WILLIAM JAMES THOMPSON.