Improvements in Mechanisms for Converting To and Fro Motion into Continuous Rotary Motion.
Year: 1892

page_text: Date of Application, 12th Nov., 1892
Complete Specification Left, 12th Sept., 1893-Accepted, 28th Oct.,
1893
PROVISIONAL SPECIFICATION.
Improvements in Mechanisms for Converting To and Fro Motion into
Continuous Rotary Motion.
I ALEXANDRE, PHILIPPE DÉSIRÉ LEVAL, Accountant of 16 Rue sur l'Eau,
Verdun, Department of the Meuse, France do hereby declare the nature of this
invention to be as follows:-
The mechanism which I have devised for converting a to and fro vertical motion
into a continuous rotary motion is specially intended to be used in communicating
driving motion to bicycles and other like vehicles or for other analogous purposes.
The mechanism is composed, broadly speaking, of an articulated isoscele
triangle ABC Fig. 1, the apex B of which, constituting the point of application
of the vertical force, moves in a vertical line B H and the lower apexes A and C
of which move on a fixed horizontal line L T, the object being to convert the
vertical motion of B into a rotary motion.
In order to obtain the said conversion, the apexes A and C actuate two connect-
ing rods connected to the opposite arms of a crank, the axis of which is in an
extension of the horizontal line L T, a link C D lying alongside of L T carries
back at D the starting point of the connecting rod operated from the apex C, the
other connecting rod being connected at A. The starting point of both connecting
rods is thus at an equal distance from the axis of the crank to be driven. The
numerical value of the angle B is 45 degrees; the same increases practically to
about 140 degrees, at say B².
The progressive development of the angle B will determine at A and at C two
equal forces, the horizontal components of which (utilized in a bicycle for instance)
are in constant progression.
Fig. 2 illustrates a further diagramm. The one connecting rod, operated from
the apex C, will lie between the points D & P, and the other connecting rod,
operated from the apex A, will lie between the points A & R; the crank will be
formed of two arms Q P and Q R, the shaft being represented by Q. If a force
be applied at the point B, so as to lower the latter to say B', the apex C will have
moved the link CD to C' D¹ and at the same time the connecting rod into the posi-
tion D' P', whilst the apex A will have moved from A to A' and at the same time
the connecting rod into the position A' R', so that the crank pins will have moved
respectively from P to P¹ and from R to R. The extreme positions of the triangle
are at B' D C the same corresponding to the positions P and R of the crank pins.
One half revolution of the crank shaft Q will thus have been effected; the second
half is imparted by another similar mechanism placed alongside of the one herein-
before described.
The points A and C, Fig. 1, of the triangle are provided with rollers bearing on
rails. The point B is guided in suitable bearings. The triangles may also operate
in another position than the vertical one, and be actuated by any suitable force.
Dated this 12th day of November 1892.
A. I, D. LEVAL,
By L. W., per F. B.

page_text: •
COMPLETE SPECIFICATION.
Improvements in Mechanisms for Converting To and Fro Motion into
Continuous Rotary Motion.
I, ALEXANDRE PHILIPPE DÉSIRÉ LEVAL, Accountant, of 16 Rue sur l'Eau,
Verdun, Department of the Meuse, France, 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 :-
The mechanism I have devised for converting a to and fro vertical motion into a
continuous rotary motion is specially intended to be used in communicating driving
motion to velocipedes and like vehicles and for other analogous purposes, and con-
sists in an improved combination of links, rods, guides and cranks for effecting the
said conversion of motion.
On the sheet of drawings appended hereunto, Figs. 1 and 2, are diagrams of my
improved mechanism or motion;
Fig. 3 a side view of part of the mechanism as carried out;
Figs. 4 to 8, detail sketches of various parts of the same on a reduced scale;
Fig. 9, a side view of a tricycle with an outline of my improved mechanism
applied thereto.
The mechanism is composed, broadly speaking, of an articulated isosceles
triangle A B C, Fig. 1, the apex B of which constituting the point of application of the
vertical force, moves in a vertical line B H, and the lower apexes A and C of which
are disconnected and move on a fixed horizontal line L T. The apexes A and C are
connected by rods to opposite crank pins P R, Fig. 2, of a double throw crank, the
axis of which is in an extension of the line GT. The apex A is connected directly
by a connecting rod to the crank pin R, while the apex C has a link C D attached
to it moving likewise in or alongside the line L T, the end D of which is connected
by a rod to the crank P. The object of applying this link CD is to make the
connecting rods A R and D P, of equal length.
If a force be applied at the joint B so as to move it, say from B to B', Fig. 2, the
apex C will be pushed outwards to C¹, and the link CD will assume the
position C¹ D', and the connecting rod D P, the position D' P¹. At the same time
the apex A is pushed to A' and the connecting rod A R into the position A' R',
so that the crank pins will have moved respectively from R to R' and P to P¹. By
further depressing the apex B, the crank pin R will arrive at P, and P at R, when
further downward motion of the apex B is stopped and the crank shaft M has made
half a revolution. By arranging a second set of mechanism alongside of the one
described but with the apexes A and C connected to crank pins diametrically
opposite to pins R and P respectively, so that the apex B of this set is in its highest
position when the apex B of the first set is in its lowest one, and applying force to
the apex B of the second set while relieving that of the first set from pressure, a
further half revolution of the shaft M is obtained and the first set of mechanism
returned to its starting position.
By alternately applying pressure to one and the other set, a continuous rotation
of the shaft M is obtained.
The arrangement before described in principle may be carried out in practice
and applied for driving velocipedes somewhat in the following manner : For each
foot of the rider, I arrange a treadle P, Fig. 3, which is guided on each side by
a projection S on the turned down ends of the treadle, entering a slot or groove
in a bar or between two bars G G. These bars are rivetted vertically to a
horizontal rail R on each side of the treadle P. To the latter a pin or shaft A is
attached on which the links B and B' are hinged. These links may have forked
ends as shewn by Figs. 4 and 5, or may be formed of pairs of links, placed side by
side, or one pair between the other pair, and they have pins or shafts C C¹ passed
respectively through their lower ends upon which rollers L are mounted on each

page_text: Bide which roll on the rails R. The pin or shaft C has a connecting rod A¹
Fig. 6, attached to it, the other end of which actuates one of the crank pins of a
double throw crank. The shaft C₁ has a drag link D, Fig. 8 connected to it,.
the other end of which is likewise guided by rollers rolling on rails R and is
connected to a connecting rod B, which actuates the other crank pin of said double
The
throw crank, the two crank pins being diametrically opposite each other.
connecting rods are bent to pass over the shafts or pins C and C₁ respectively and
pass between the links B B' or at the side thereof. A rail R S Fig. 3 is arranged
above the rollers L to prevent their lifting during the return stroke.
As already stated, there are two treadles P and Pi Fig. 9, one for each foot of
the rider, with links connected to them as described, the connecting rods being
attached to a four-throw crank shaft M, having two pairs of diametrically opposite
cranks, all in the same plane, and the rods are so connected that one treadle is in
its highest position when the other is in its lowest position as shewn on Fig. 9.
The four connecting rods impart a rotary motion to the crank shaft M, which is
transmitted by chain gearing as indicated or by other suitable means to the driving
axle.
It is obvious that the details of the mechanism may be and will have to be varied
The
according to the kind of machine or purpose for which it is employed.
triangles may also operate in another position than the vertical one and be actuated
by any suitable force.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. The arrangement of mechanism for converting a vertical to and fro motion into
a continuous rotary motion composed of two sets of parts each set consisting of
two links joined together so as to form an articulate isosceles triangle; the joint
being guided in a vertical line and the other ends of the links in a horizontal line
and connected by connecting rods of equal length to diametrically opposite crank
pins, one directly and the other by means of a drag link, and said two sets of parts.
being arranged so as to act alternately, substantially as herein before described
and illustrated.
2. The arrangement and use of mechanism for imparting rotary motion to a shaft
by means of treadles operated alternately substantially as hereinbefore described
and illustrated by the drawings.
Dated this 11th dor of Santember 1893
R. J. URQUHART,
57, Barton Arcade, Manchester, and 5, Clayton Square, Liverpool,
Consulting Engineer and Patent Agent.