Year: 1888

page_text: Date of Application, 26th Jan., 1888
Complete Specification Left, 26th Oct., 1888
Complete Specification Accepted, 30th Nov., 188
I, JULES MICHEL MARIE TRUFFAULT, of 23 Boulevard de Strasbourg, Paris,
France, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
In order that tricycles may readily run round curves it is necessary that the two
wheels whose axes are in line with each other should be capable of revolving at
different speeds, for which purpose they are generally mounted upon a divided axle
with a so called "differential coupling." Such couplings are however liable to
unequal wear whereby accidents are caused and they are also expensive to make.
According to my present invention I dispense with such differential couplings by
arranging the two wheels to work with friction upon a common undivided axle, which
is rotated by an endless pitch chain, and pitch wheels from a treadle shaft in the usual
manner. The friction of the wheels upon the axle is so regulated as to be sufficiently
great to enable the axle to transmit its rotary motion to the wheels without slipping
under ordinary circumstances, and yet to allow the one or other wheel to slip upon it
when in passing round curves such wheel has to revolve at a slower speed than the
other one.
For this purpose the ends of the axle are formed with a cylindrical part on which
fits the cylindrical hole of the nave of the wheel and at the inner end of such
cylindrical part is formed a shoulder or collar on the axle, with a coned surface while
the outer end of the cylindrical part has firstly a square or polygonal part and then a
threaded end for the reception of screw nuts.
The nave has at each end of its cylindrical part a cup shaped flange, to the rim of
which are fixed the wire spokes, and against the inner face of which is placed a disc
or washer by preference of leather, but which may also be of wood, caoutchouc or
other material capable of producing friction.
Against this washer is placed a second disc or washer of steel or other suitable
metal of which the one at the inner end of the nave has a coned hole fitting the
coned surface of the shoulder while the other one has a square or polygonal hone

page_text: fitting the square or polygonal part of the axle. The nave with the washers being
slid on the axle the metal washers are pressed tightly against the leather ones and
these against the inner faces of the flanges by means of the screw nuts on the outer
ends of the axle thus producing such an amount of friction between the washers and
the flanges of the nave, as to cause the wheels to be carried round by the axle, but to
allow the nave to slip on the axle when the rotation of the one wheel is retarded on
passing round curves.
acil 1
T
1000
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Tricycles.
I, JULES MICHEL MARIE TRUFFAULT, of 23, Boulevard de Strasbourg, Paris,
France, Manufacturer 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 :-
In order that tricycles may readily run round curves it is necessary that the two
wheels whose axes are in line with each other should be capable of revolving at
different speeds, for which purpose they are generally mounted upon a divided axle,
with a so called differential coupling. Such couplings are however liable to unequal
wear whereby accidents are caused and they are also expensive to make.
According to my present invention, I dispense with such differential couplings by
arranging the two wheels to work with friction upon a common undivided axle, which
is rotated by an endless pitch chain and pitch wheels from a treadle shaft in the usual
manner. The friction of the wheels upon the axle is so regulated as to be sufficiently
great to enable the axle to transmit its rotary motion to the wheels without slipping
under ordinary circumstances, and yes to allow the one or other wheel to slip upon it
when in passing round curves such wheel has to revolve at a slower speed than the
other one.
For this purpose 1 attach the wheels to the axle as I shall describe referring to the
accompanying drawings. Fig. 1 is a side view of one form of tricycle to which my
invention is applied and Fig. 2 is a longitudinal section of the nave of one of the
driving wheels shewing its fitting on the axle. gare the pedals driving the chain
wheel h which by a chain i works the chain pinion on the driving axle thereby
giving motion to the wheels in the usual way. Referring to Fig. 2, a a¹ are the

page_text: bosses of the nave A which receive the spokes b. The axle B has a coned neck e on
which is forced a metal washer d that fits in a recess of the boss a having under it a
washer e of leather, or it may be of wood caoutchouc or other suitable material
having considerable friction on metal. At the other end of the nave in a recess of
the boss a¹ there is a similar washer c¹ pressed on by a metal washer d¹ which fits on a
square or polygonal part of the axle and is pressed by a nut 7 secured by a lock
nut screwed on the threaded end m of the axle. By screwing up more or less the
nuts, the washers c c are more or less compressed, causing more or less friction on
the washers d d¹ and the faces of the nave recesses, and this friction may be adjusted
so that the axle B will drive the wheels equally or nearly so, but, in the turning of the
vehicle, will allow one of them to slip more or less.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
Fitting the driving axle of a tricycle to its two wheels with friction washers
adjustably pressed against faces of the naves, substantially as and for the purpose set
forth.