Year: 1886

page_text: We, WILLIAM THOMAS SHAW, WILLIAM SYDENHAM and ARTHUR SYDENHAM all of
73A, Chiswell Street Finsbury Square London E.C. Engineers 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 :-
Our improvements in tricycles and other velocipedes consist of an improved method
of steering and driving whereby greatly increased advantages are secured both as
regards ease of propulsion and the safety and comfort of the rider. In the case of a
single tricycle or tandem for two riders we make use of an ordinary hay fork frame
carrying two equal wheels abreast in front and a central driving wheel behind. The
central part of the frame between the prongs of the fork is curved forwards so as to
admit of the back wheel being brought forward and well under the saddle of the front
rider whose weight is thus advantageously thrown upon the driving wheel. The
propelling force is applied to the latter by means of side levers connected at the one
end with the crank of the driving wheel supported intermediately by a link and
carrying a pedal at the opposite end. In order to avoid the inconvenience of a large
driving wheel which would necessarily stand out at a great distance behind the front
rider we use a wheel of small dimensions say from 38 in. to 42 in. in diameter and this
wheel is geared up and made to run as if of an increased diameter by means of an
internal gearing contained within the hub of the driving wheel as described hereafter.
The length of the lever and the position of its fulcrum support are so designed that
the pedal in procuring approximately one half revolution of the crank shall descend
through one half of an elliptical orbit of about 12 in. in length and 3 in. to 4 in. in
width disposed almost vertically as regards its longer diameter. The supporting link
of the lever is so placed that the forward movement of the driving wheel is procured
when the pedal is descending through the back half of the ellipse whilst the backward
movement of the driving wheel is effected when required by pressure of the pedal
down through the forward half of its orbit. The effect of this is that the line of
pressure of the foot is brought back almost vertically under the weight of the rider.
A saddle is mounted on a suitable support a few inches behind the vertex of the
driving wheel for the use of a second rider and a handle bar is placed conveniently
n front of him as on a bicycle. Curved arms attached to the crank ends of the side-
evers carry pedals conveniently placed so that the rider may pedal through an

page_text: elliptical orbit differing somewhat in shape from the orbit of the front pedals but
giving an advantageously vertical action. The steering is effected by means of the
two front wheels which are made to turn to the requisite extent with either or both
hands and with the degree of convergence required for any given curve.
This result
is effected in the following manner.
The spindles or axles of the two front wheels project outwards from vertical hollow
cones into which the ends of the fork arms of the frame which stand downwards enter.
Each cone has also an arm extending backwards from it which for convenience we
call the tiller. The tillers are made to simultaneously turn the cones when steering
but not to an equal extent-the tiller of the inside wheel being turned through a
greater angle than the tiller of the outside wheel. We effect this by giving motion to
each tiller arm by a slide mounted on it which is jointed to the arm of a bell crank
lever. The arms of the two bell cranks are inclined to the tillers when in their central
positions and both bell crank levers are made to turn simultaneously and through
equal arcs in the same direction but by reason of their being inclined to the tillers
the end of one passes through a greater distance away from the central position of the
one tiller than the other passes through and thereby the one tiller is turned to a greater
extent than the other.
The diagram A illustrates the way in which the position of the axis of the bell
crank relatively to the axis of the tiller is determined.
In this diagram a is the axis of the tiller- the axis of the bell crank-the line a. c.
the central position of the tiller-the line a d the position of the tiller of the outside
wheel when the machine is being turned in the smallest curve which the machine is
required to turn in say a curve of 7 feet radius as illustrated at Figure 2-and the
line a e the required corresponding position for the other tiller.
The point b. is so set that the lines be, bc, bd, which represent the three positions
of the bell crank arm are of equal length and so that at the same time the lines be, bd,
make equal angles with the line bc.
With the point in the position shown in the diagram the wheels could be set to
turn the machine in a smaller curve than one of 7 feet radius but practically it is not
necessary that it should be capable of turning in a smaller curve.
To cause both bell cranks to turn simultaneously we couple their shorter arms by
links with the opposite arms of a lever which turns on a fulcrum at its centre on the
central line of machine. The axis of each bell crank is carried upwards and at the
top has a steering handle upon it so that the steering may be effected by either one
or by both of the hands.
The principle of converging the two front steering wheels has been previously
applied to tricycles (see Bloods Patent 4250 of 1876) but by a method entirely
different from that which is explained above.
It is obvious that our improved steering apparatus although here described in
connection with a lever tricycle can also be used on tricycles of the same class driven
by rotary pedal crank, whether the power is conveyed to the driving wheel by pulleys
and chain by connecting rods, or by other similar means.
One of the steering handles is fitted with a lift up handle by means of which a
spoon brake can be instantly applied to the back wheel. From the construction of
the gearing within the hub which will be explained hereafter the back or driving
wheel can be driven either at a fixed ratio in relation to the pedal revolution, or at two
or more different speeds according as the gearing in action or running solid. A
speeding up gear or "Crypto" is used, and by a further improvement the gear, when
it is driving the wheel at the higher velocity, provides the rider with semi free pedals,
i.e. he can at any moment keep the pedals stationary without retarding the progress
of the machine. When the hub gearing is capable of being driven at more than one
speed in relation to the crank revolution, a change speed apparatus or striker is
required. This striker connected by rods and bell cranks with the hub gear is fixed
conveniently near the hand of the rider on the side opposite to that on which the grip
handle of the brake is fitted.
When it is desired to adapt this form of machine for use as a double tandem i.e.

page_text: for two three or four riders, we construct it as follows. The frame of the machine as
regards its front portion is T shaped, the front or steering wheel being placed at the
end of the stem. The other two opposite extremities of the T are merely used to
carry short arms serving to hold the purchase handles and are not made to carry as is
commonly the case the two driving wheels. The saddle pillars for the two front riders
are fixed on the frame centrally and equidistant on each side of the stem of the T.
The frame immediately beneath the front saddles is curved forwards so as to bring the
driving wheels forward and as much as possible under the saddles. On each side of
the saddle pillars two strong arms are carried back attached at their backward ends to
upright forks. Within these forks and arms are fixed the driving wheels arranged
exactly on the same principle as in the single tandem above described. Between the
two front riders and equidistant from the central stem, convenient purchase handles
are fitted, either of which can be connected at will with the steering head of the front
wheel by means of a short lever and connecting rod. Within these two handles aro
fixed pull up or grip handles which actuate spoon brakes, fitted so as to act respectively
on the two driving wheels. A few inches behind the vertex of each driving wheel is
fixed a saddle whilst the crank ends of the side levers each of them carry a curved
arm and pedals by means of which the hind riders assist in propelling the machine.
Various stays and struts are used so as to give rigidity to the whole machine. The
change speed apparatus connected with the hub gearing is attached to a small lever
fixed within easy reach of the two riders on the central stem of the machine, so that
by a single action either rider can instantaneously change the gearing of both wheels.
Figures 1 and 2 represent the single machine or tandem for two riders described
above. The form and construction of the machine will be readily understood from
the figures. On the plan of the machine Figure 2 dotted lines are drawn showing
the directions assumed by the axes of the respective steering wheels and the degree
of their convergence. When a machine is built to turn with a radius of about 7 feet
it will be noted that these axes make an angle of 11° and that the wheels themselves
converge to a similar extent.
Figure 1 also shows by dotted lines the orbits described by the pedals. Figures 3
and 34 show the actual construction of the steering apparatus with its bell cranks a,
connecting rods b and the bent lever c. pivoting at the centre and giving to the whole
of the parts the requisite combined movements.
The remaining parts are also clearly shown, viz. d the spindles of steering wheels,
and d¹ the vertical cones to which they are attached; e the tillers attached to d¹;
a¹ the sockets sliding on e and a the bell cranks fixed to the steering spindles f; b the
connecting rods coupling the bell cranks to the curved lever c.
Figure 4 shows a side view and Figure 5 a plan of the double tandem for two three
or four persons as described above, from which its construction will be readily under-
stood. Figure 6 represents the speeding up gear which we make use of when it is
desired to have only a single and invariable speed on the driving wheel. It has the
same construction as that which is used in the Crypto Dynamic Gear fully described
in Patents Nos. 2174* in the year 1882, 3230 in the year 1882 and 4803 in the
year 1882. In the particular combination here given the epicyclic train is made up
of the following components. Central pinion 24 teeth, planet wheels 12 teeth,
internal wheel 48 teeth. The stud disc carrying the planet wheels is keyed firmly to
the spindle whilst the central pinion is locked to the frame of the machine. The
internally toothed wheel is constructed as one piece with the hub of the driving wheel,
and the latter is thus driven round 1 revolutions for each single revolution of the spindle
Figure 7 represents a variation of the preceding construction. In this arrangement
the epicyclic train is made up of the following components. Central wheel 16 teeth,
planet wheels, three pairs each containing 12 teeth, internal wheel 48 teeth. Each
pair of planet wheels engages one pinion with the internal wheel, the other with the
central pinion. In this case the internal wheel is the driver and is keyed to the spindle
whilst the stud disc carrying the planet wheels is made to run as one piece with the
hub of the driving wheel, the central pinion being as in the preceding construction
fixed to the frame of the machine. It is obvious that this arrangement of epicyclic

page_text: gearing can also be used in conjunction with the clutch shown on Figure 8 also with
the various clutches described in the above cited Patents, so as to give two speeds.
Figure 8 shows the construction of the hub driving wheel when it is desired to have
two speeds, one the same as the actual diameter of the wheel, the other speeded up to
any desired degree. As regards the epicyclic train it is similar in design to the gears
described in the Patents already cited, but as regards the clutch the improvements
described below are introduced. c is the internal wheel which is constructed in one
piece with the hub c¹. b represents the planet wheels, the stud disc of which b' is in one
piece with the crank spindle i of the driving wheel. a is the central pinion with sleeve
moving freely round the spindle and the boss of the fixed back 9, the latter being
firmly fixed to the frame of the machine. The external circumference of the sleeve a
is square in section so as to carry round with it the clutch disc d. This disc carries
on its outer periphery the same number of teeth as the internal wheel with which the
diagram shows it engaged i. e. the central pinion a is thus locked to the internal
wheel c and the whole of the epicyclic train is then caused to revolve as one piece with
the hub. The disc e. revolves freely on d and is constructed with a circular recess
with peripheral tapered grooves e¹ facing the space e². The disc e is grooved for the
reception of the fork h, by means of which the clutch is slided backwards and
forwards as hereafter described. The cavity e² between d¹ and e¹ is used to receive as
many small rollers or balls as there are tapered grooves in the disc e, making the
construction known as the Bourdin clutch see Patent 2232 in the year 1874. The
outer periphery of the disc e is armed with internal teeth e³ which when e and d. are
slided along sleeve a are caused to engage with the ring of internal teeth g¹ formed in
the fixed back g. The purpose of this will presently be seen; for supposed and e
which are held together laterally by the ring f to be drawn over by the fork h so that
the teeth es of the disc e are engaged with the ring of teeth g' in the fixed back, then
the disc e will hold stationary the clutch disc d, and by consequence the central
pinion a so long as e and d are held fast together by the Bourdin clutch interposed
between them as already described. The direction in which the recesses are tapered
insures that this shall happen when the machine is being driven forward through the
crank spindle. If however the pedals and crank spindle are held stationary the hub
with internal wheel continues to rotate without being retarded, seeing that the rollers
of the Bourdin clutch then fall into the larger ends of the tapered recesses and the
disc d, is consequently free from engagement with e, and is carried round by the square
sleeve of the central pinion a.
By this improved construction the rider enjoys the advantage of being able at will
to hold his feet and the pedals at rest when running down hill or should he require
to use back pressure on the pedals he can at once do so by throwing the clutch over
into the opposite position. This is effected by moving a small lever placed close to
the hand, and joined up by a connecting rod with the fork h.
It will be obvious that the gears above described are also applicable to ordinary
bicycles and tricycles. Figure 9 represents a gear which we have specially designed
for use on tricycles and by means of which three different speeds may be obtained.
Figure 9 represents the gear as prepared for use on central geared tricycles, a and a¹
represent the main axle separated into two portions and socketted as shown. The half
axle a, has keyed to it the internal wheel n." The other half axle a¹ has keyed to it
the central pinion m. These two wheels with their intermediate pinions form the
balance gear. The pinions run on studs carried by the stud disc d. but the details are
not given as they are fully described in Patent No. 2061-1884-for combined crypto
and balance gear. The stud disc d also carries the studs of the planet wheels or
pinions c, which are of two diameters. 6 is an internally toothed wheel in one piece
with the chain pulley b'. Side by side are two central pinions e and f completing the
epicyclic train as described in the Patents first above cited. The stud disc d has a
long sleeve which turns freely on the main axle a¹. The central pinion also has a
long sleeve revolving on the sleeve of d and is continued upwards by a disc fl
terminating at f2 in a peripheral ring of teeth. The central pinion e also has a long
sleeve free to revolve on fand continued upwards by a disc e¹ and terminating in a

page_text: broad ring of peripheral teeth e², k is the fixed back of the crypto firmly fixed to the
frame of the machine so that it cannot rotate. On its interior surface it is armed with
a broad ring of teeth which teeth are the same in number as those of the rings
previously referred to. i is the clutch by means of which the central pinions can be
locked to the fixed back or to the chain pulley as may be required. This clutch i
carries two rings of teeth, the inside row to engage with the teeth e², the outer row i²,
to engage with k¹ or ', when slided backwards and forwards by means of the grooved
ring and the fork 1, g is a disc fixed to b and with its peripheral edge shaped into
seven or more tapered grooves. h is a disc revolving freely on the sleeve of b. It
has a deep recess on the side towards g forming cavities or interspaces bounding the
tapered grooves and in which rollers or balls are placed thus forming a Bourdin
clutch. The smaller ends of the tapered grooves point in the opposite direction to
that in which the pulley b', has to move when it is driving the machine forwards.
The disc h carries at its outward edge a ring of face teeth 1 pointing towards the
teeth 22. When the clutch i, is pushed along up to hits two rows of teeth ¹ and
engage the former with the latter with ¹, thus the central wheel e, and the disc h
are locked together. h in its turn being locked to the chain pulley by means of the
Bourdin clutch, it follows that when bis driven with the clutch teeth in this position
the whole rotates as one solid piece. If however the pedals and consequently the
chain pulley are held stationary whilst the machine is running forwards, the stud disc d
is free to run round, because in that case the rollers of the Bourdin clutch roll to the
larger ends of the tapered recesses and being then free to move the central wheel
is also free as it can now carry h around with it. When however the clutch i is
drawn in the contrary direction so as to lock together e² and k¹ or fand k¹ then the
Bourdin clutch ceases to be operative, the locking disc h being then entirely
disconnected.
e,
It will be seen that from this construction the rider enjoys the advantage of free
pedals at the highest speed, whilst should he require to back pedal he has merely to
draw the clutch into such a position as to engage either of the two central wheels
with the fixed back k. The bell crank by which the clutch is actuated, is controlled
by a small connecting rod attached to a small quadrant piece or other convenient form
of striker near the hand of the rider, who is by this means enabled to change the
speed with perfect facility.
If however it should be preferred to have the means of back propelling at
the highest speed as well as at the other two speeds it is only necessary to omit the
grooved disc g with the rollers and to make the disc h in one piece with the chain
pulley.
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. The single tricycle substantially as described with reference to Figures 1 and 2.
2. The tandem tricycle substantially as described with reference to Figures 1 and 2.
3. The tricycle for two three or four riders substantially as described with
reference to Figures 4 and 5.
4. The steering gear substantially as described with reference to Figures 3 and 3*.
5. The driving gear substantially as described with reference to Figure 6.
6. The driving gear substantially as described with reference to Figure 7.
7. The two speed gear substantially as described with reference to Figure 8.
8. The three speed gear substantially as described with reference to Figure 9.