Improvements in Triple Cylinder Engines.
Year: 1897

page_text: Date of Application, 2nd Oct., 1897-Accepted, 4th Dec., 1897.
CUMPLEIN DIECIFICATION.
Improvements in Triple Cylinder Engines.
I, PETER BROTHERHOOD, of Belvedere Road, Lambeth, in the County of London
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
ollowing statement :—
f My invention relates to engines worked by fluid under pressure acting in three
cylinders which radiate around a central crank shaft, the fluid acting on the pistons
only in the one direction forcing them successively towards the shaft, while their
return strokes are effected by the crank. My present improvements relate chiefly to
the construction and action of the connecting rods. in conjunction with recesses in
the cylinders for discharge of exhaust, and to the construction and actuation of the
piston valves for admitting the working fluid to the cylinders as I shall describe
referring to the accompanying drawings.
Figs. 1 and 2 are two central sections of an engine according to my present
invention, taken on planes at right angles to each other.
Fig. 3 is a sectional plan of one of the cylinders on the lines 3...3 of Fig. 1.
Fig. 4 is an elevation of the cam and rubber.
Each piston P has through it a slot p which, while the piston is making its back
stroke partly or wholly coincides with a slot c through the rounded outer end C of
the connecting rod, this slot being at such an angle that the slots coincide only while
the connecting rod is moving at an inclination to the right of its central position.
Each cylinder has four recesses R which extend some distance along the cylinder
from the central cavity A in which the crank B revolves. The crank shaft D is
tubular giving passage for exhaust. The crank pin E is also made tubular for the
sake of lightness, and to it is fixed a disc F made with a heavy part f to counter-
balance the crank pin which is also partly counterbalanced by a heavy part 6 of the
crank.
On the disc F is a cam G against which bear three guided rubbers N, one for each
valve stem 8 which butts against the rubber. The valve S is of piston form having a
hollow stem enclosing a spring which keeps the stems and rubber N pressed against
the cam G. The working fluid is admitted into, an annular passage which
communicates with the three valve chests K. Each connecting rod terminates at its
inner end M in a hollow fitting on the crank pin, and has on each side a projecting
lip engaged in annular grooves L formed on the faces of the crank B and the disc F
respectively. The engine operates in the following manner.
The piston valve S being in such a position as to uncover the port at the end of
the cylinder, fluid under pressure passes from the valve chest into the cylinder and
propels the piston towards the central shaft until the cam moves the valve S to the
position where it covers the port. As the piston approaches the end of its stroke it
uncovers the recesses R allowing a large portion of the fluid which has acted in the
cylinder to escape into the (central cavity and thence through the tubular shaft D;
soon after the connecting rod has passed its dead centre, the piston being about to
cover the recesses R, the slots p and c come into coincidence, so that when the
recesses R are quite closed against escape, the residuary fluid in the cylinder escapez

page_text: through these slots until the piston completes its stroke, whereupon the action is
repeated. As each piston in its turn propels the crank through part of a revolution
during its stroke in the one direction, and is moved back by the crank, continuous
revolution of the crank is effected, the connecting rods being always under stress in
only the one direction.
An engine in some respects similar to that which comprises my present
improvements was described in my previous Specification No. 3989 of 1887 I
therefore make no general claim to an engine of this kind but,
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 :-
1. The combination of the cylinder recesses and the slots through the piston and
the outer end of the connecting rod for allowing discharge of exhaust, substantially
as described.
2. The construction of the inner end of the connecting rod with rounded hollow to
fit the crank pin and lips at the sides engaged in annular grooves of the crank and
disc, substantially as described.
3. The combination of the valve operating cam, with the guided rubber and spring
valve stem for each cylinder substantially as described.
Dated this 2nd day of October 1807
ABEL & IMRAY,
Agents for the Applicant.