Improvements in Apparatus for Equalizing the Power Used where Uniform Revolution is to be Imparted to a Wheel or Axle, as for instance, in Driving Tricycles.
Year: 1888

page_text: Date of Application, 1st Nov., 1888
Complete Specification Left, 1st Aug., 1889-Accepted. 14th Sept., 1889
PROVISIONAL SPECIFICATION
Improvements in Apparatus for Equalizing the Power Used where
Uniform Revolution is to be Imparted to a Wheel or Axle, as for
instance, in Driving Tricycles.
I, FRÉDÉRIC MALFAIT, of Boulevard Henri IV. Paris, in the Republic of France,
Watchmaker, do hereby declare the nature of this invention to be as follows:-
This invention has for its object a novel arrangement of an elastric spring, by which
a part of the power used to set a crank in revolution is given out again when such
crank is passing its dead points so that a uniform speed and distribution of force is
obtained.
Supposing the invention to be applied to a tricycle, I prefer to use a single driving
wheel at the back, and two smaller wheels in front, running loose upon their axles,
the whole being connected by a frame carrying a saddle. The frame or backbone is
extended forward and curved down, its end carrying a crossbar upon which the front
ends of two pedal levers are pivotter. The other ends of these pedal levers drive the
principal wheel by means of a crank upon each side connected to the levers by
connecting rods, suitable foot plates of metal or india-rubber being fixed upon the
levers in a convenient position for the feet of the rider.
To the frame or backbone is firmly fixed, at the side of the driving wheel, one end
of an elastic steel spring, to the outer end of which is jointed a connecting rod the
other end of which fits upon the same crankpin as the principal connecting rod from
the pedal.
The spring is so placed that in its normal position it is parallel with the crank, but
is bent to its fullest extent a little before the latter has reached its dead points.
In the latter position the spring exercises its greatest force, and as soon as the dead
point is passed its elasticity aids the movement of the crank until it regains its normal
position, when the force upon the other crank upon the other side of the wheel is in a
position to act upon it and bend it, the force required to do so being again given out
by its elasticity to assist the last named crank past its dead point.
The usual effect of the spring depends upon its position, as its elasticity could not
be utilized if it operated directly vertically or horizontally, but only when adjusted in
the position described.
The two front wheols are carried in the ordinary way in forks turning in vertical
bearings and connected together by a rod, and they are both turned to the right or
left for steering by a steering bar and connecting rod in the usual way. The lower
ends of the forks, which carry the axles, are preferably curved somewhat backward.
By my invention, driving chains are avoided, and the rider exercises considerable
force from the length of the pedal levers, and the tricycle is very easy to work.
As there are practically no dead points for the cranks, a constant and uniform
force is obtained by the operation of the spring.
It is evident that the invention may be applied in all cases in which movoment
is communicated to a shaft by means of cranks and connecting rods.
Dated this 1st day of November 1888.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Equalizing the Power Used where
Uniform Revolution is to be Imparted to a Wheel or Axle, as for
instance, in Driving Tricycles.
I, FREDERIC MALFAIT, of Boulevard Henri IV. Paris, in the Republic of France,
Watchmaker, 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, and accompanying drawing, that is to say :-
This invention has for its principal object a novel arrangement of an elastic
spring, by which a part of the power used to set a crank in revolution is given
out again when such crank is passing its dead points so that a uniform speed and
distribution of force are obtained.
In the accompanying drawings the invention is shewn applied to a tricycle but
it is to be understood that it is applicable to all kinds of motors in which move-
ment is communicated to a driving wheel by means of connecting rods and cranks.
Figure 1 is an elevation of the tricycle and figure 2 a plan. A large driving
wheel is fixed upon its axle at the back of the machine and is connected to two
small front wheels a by a frame upon which is fitted the saddle k. The two
wheels a turn loose upon their axles. The frame has a curved prolongation at
the end of which is fixed a cross-bar m which serves as a pivot for the two pedal
levers e e.
These pedal levers drive the wheel g by means of connecting rods f' and
cranks q.
A piece of india rubber or of grooved metal n is fixed upon each of the pedal
levers to receive the feet of the rider.
Upon the frame is fixed a spring o which forms an essential part of the invention.
This spring o is jointed at its outer end to a second connecting rod p the other end of
which turns upon the same crank pin as the connecting rod f.
It is arranged in such a position that when at rest it is exactly parallel to the
crank and is bent by the crank as it passes from this position and begins to
unbend before the connecting rod of the pedal lever reaches its dead point, that is to
say it acts at the moment when a point c or x in the diameter of the wheel reaches
for instance the point or, the point being nearly an eighth of the circumference
of the wheel from the vertical diameter.
The action of the spring having assisted the crank over the dead point, when the
other point is reached it is again bent by the pressure upon the other podal which
it assists over the dead point in the same way.
The action of the spring o is absolutely dependant upon its adjustment in the proper
position. It would not answer the required object if it operated either vertically or
horizontally, but it is essential that it should be arranged in the precise position
described, and it then produces a perfect continuity of the force applied.
In the tricycle the two wheels à a turn round vertical pivots and are kept parallel
to each other by arms and a connecting rod so that both wheels can be turned
together by means of arms and a connecting rod c regulated by the steering handle d.
This method of turning and the arrangement of the forks t t in which the wheels a a
are carried and which are curved slightly back at their lower ends as shewn produce a
simultaneous movement of the two wheels and serve to reduce the liability to over-
turning which often happens from the action of centrifugal force in describing
curves too quickly.
The improved system: has many novel and important advantages. First, it does
away with endless chains or gear which are objectionable in the transmission of the
power on account of their friction and the resistance occasioned by dust and other
causes. Second, it enables great force to be exercised from the facility with which
the rider, owing to the length of the levers, can throw the whole weight of his body
alternately upon each pedal. Third, it facilitates the steering and on account of the
curving back of the forks which carry the steering wheels reduces the liability to fall

page_text: from the action of centrifugal force in describing curves too rapidly. Fourth, by
the method of application of the auxiliary spring it annihilates the dead points of
the cranks and causes the force applied to be practically constant. Fifth, it facili-
tates transport and storing, since by removing a single nuts one of the steering
wheels together with the arm can be removed, the width of the machine being
reduced by one half.
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
1. The method of obtaining a constant force by means of the connecting rod,
crank, and auxiliary spring, so that by a simple backward and forward movement
upon the crank from a given point, a constant force is obtained such as would be
produced by two backward and forward movements acting at about right angles to
each other, substantially as described and shewn.
2. The arrangement of two pedal levers acting by connecting rods and cranks,
acting upon a single back central driving wheel, substantially as described and
shown.
3. The application to a tricycle of the novel method of steering by means of two
wheels turning parallel to each other, substantially as described and shewn.
4. The arrangement of two steering wheels in forks curved back at their lower
ends so as to produce an excentric displacement which reduces the effect of centri-
fugal force in describing curves, substantially as described and shewn.
5. The arrangement by which the removal of a single nut enables the width of
the machine to be reduced by one half, substantially as and for the purpose
described.
Dated this 1st day of August 1889.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Patentee.