Year: 1887

page_text: I JEAN BONICARD of Bienjac (Gironde) in the Republic of France, Engineer 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 object of my invention is to provide means for increasing the work of steam
engines and other motors and the invention consists essentially of an arrangement of
levers interposed between the motor and the driving shaft to which power is to be
transmitted.
This lever mechanism can be of a length five or six times greater than that of
the stroke of the piston without however requiring more space than is necessary
for an ordinary engine.
Further the application of this lever mechanism allows of driving away with the
valve excentrics and of employing in place thereof a crank keyed on the oscillating
shaft of the lever mechanisin.
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing in which figures 1 and 2 shew
respectively an elevation and a plan (partly in section) of a two cylinder steam engine
with my lever mechanism applied thereto. The steam which escapes from the cylinder
a, is employed to produce motive power in the larger cylinder b. To the rod a', of
each of the pistons is jointed a connecting rod c, connected to another rod d, to which
are jointed a lever e, oscillating on a shaft f, and a rod g, working a crank of the
driving shaft h, and connected to the lever e, by a short rod i.
e.
The piston rod of each cylinder is provided with a similar arrangement of lever
mechanism for increasing the power.
The valve motion mechanism of the small cylinder a, is arranged to allow of
variable expansion in this cylinder; but it is obvious that the expansion can be fixed
as is the case in the arrangeinent shewn in figure 3.
The slide valves m, n, are operated by rods o, p, and a crank », keyed on the shaft f,
at an angle of ninety degrees with the lever e; this arrangement allows of increasing
the travel of the slide valves and consequently of varying the admission and the

page_text: escape of steam into and from the cylinders by changing the position of the joints of
the rods o, p, on the crank r.
Figure 4 shews the four principal positions taken by my improved lever mechanism
during a complete stroke of the piston.
I will now describe the method of executing the proportional diagram of my
improved lever mechanism for increasing power which has just been described.
A horizontal line A, B, of indefinite length is drawn which is supposed to pass
through the centre of the cylinder (figure 5) and at two points of this line are
described two unequal circles the distance between the centres of which is from five
to six times the length of the stroke of the piston; two vertical lines C, D, and E, F,
are then drawn passing through the centres of the circles. From the four points
where these vertical lines cut the circles two diagonals D, E, and C, F, are drawn
cutting each other at G, on the horizontal line A, B. This point of intersection
becomes the centre of oscillation of the mechanism.
From the point C, an oblique line H, C, is drawn which makes an angle of from
twenty five degrees to thirty degrees with the vertical line C, D, and from the
point F, is drawn a perpendicular E, I. From the point G, is drawn a line G, K,
parallel to C, H. The line F, K, is bisected and from the centre J, is produced the
line J, L, parallel to C, H, which completes the diagram of my improved mechanism.
In the diagram the construction of which has just been described the inequality of
the circumferences, the distance from their centre and the angle formed by the first
lever with the vertical are not arbitrary and can be increased or diminished but the
invention is based on the principles that the power of the mechanism is in direct ratio
to the difference in size of the two circumferences and that upon the amplitude of
the angle and the distance of the centres of circumference depends the distance apart
of the twin levers whence results very little obliquity in the action and consequently
more effective working.
My improved mechanism for increasing power is applicable to all other motors,
hydraulic wheels and turbines, hydraulic motors with pistons, air engines, electric
motors &c.
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,
The improved apparatus for increasing the power of steam engines and motors of
all kinds such apparatus consisting essentially of an arrangement of connecting rods
and lever interposed between the piston rod of the motor and the driving shaft of the
engine, the apparatus further allowing of governing the slide valves by means of
connecting rods and cranks substantially as hereinbefore described and illustrated in
the accompanying drawing.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicant.