Improvements in Valve Gear for Multiple Cylinder Engines.
Year: 1888

page_text: Date of Application, 5th Oct., 1888
Specification Accepted, 9th Nov., 1888
[Communicated from abroad by FRIEDRICH CARI. GLASER, of 80, Linden Strasse,
Berlin, in the German Empire, Engineer and Patent Agent.]
Improvements in Valve Gear for Multiple Cylinder Engines.
I, OLIVER IMBAY, of No. 28 Southampton Buildings, Chancery Lane, in the County
of Middlesex, Fellow of the Institute of Patent Agents, 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 herein described valve arrangement for three cylinder engines or for multiple
cylinder engines, has for its object to effect the supply and discharge of the steam or
other working fluid by means of double piston valves which are quite free from
pressure and are worked from a single enclosed eccentric.
This arrangement avoids the disadvantages attending the various arrangements of
valve gear hitherto adopted, as for instance when oscillating slide valves or cocks are
employed subject to rapid to and fro movements which cause wear, looseness and
leakage, as well as irregularity in the distribution of the working fluid. Again, in
engines having piston slides worked by separate eccentric segments a certain amount
of pressure is required to act on the differential piston valves and this involves con-
siderable wear of the eccentric and of the segments which slide on it under such
pressure.
These arrangements also involve special construction of the ends of the eccentric
rods to act as exhaust valves.
A special advantage of the improved valve gear lies in the perfect relief of the
valves from pressure in any direction, and in the circular fitting by which one sided
or inexact working of the parts is entirely avoided. Moreover, in the improved con-
struction, the exhaust is regulated by means of an auxiliary slide worked from the same
eccentric rod as the main slide, instead of employing, as in engines hitherto known,
some special valve, cock, or other arrangement for the purpose.
Independently of the novel valve gear, there is provided according to this invention
for rapidly moving engines, a separate exhaust by a special passage through each

page_text: piston, which is thus made to operate as an exhaust valve, opening at the end of the
expansion period of the stroke.
The accompanying drawings shew part of a three cylinder engine arranged
according to this invention, Figs. 1 and 2 representing partial sections on planes
at right angles to each other through the axes of the slide valves.
a is the eccentric sheave fixed on the crank shaft, and surrounded by the three
separate rings bc and d, the ring 6 occupies the whole breadth of the sheave, and the
rings c and d fit on 6 on each side of the three eccentric rods b₁ c¹ d₁ which
project from b.
At the side of each cylinder is fitted the outer piston slide 6 having within it the
auxiliary slide 3 both worked from the eccentric rod b¹, the outer b' directly and the
inner by a rod" from a bracket projecting at the side of the rod b'. In like
manner the slide valves of the other cylinders are worked respectively from the
rods e¹ d¹.
The working fluid is supplied by the pipe e to the annular space surrounding the
smaller part of the slide. The exhaust passes through the ports g, and the tubular
interior of the auxiliary slide 63. In the working piston B are formed two opposite
passages k, which during most of the stroke of the piston remain closed but, towards
the end of the stroke, open to the central cavity of the engine, so that by these, as
well as by the slide valve, there is free passage for exhaust.
During the return stroke of the piston the passages k are again closed.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In three cylinder or multiple cylinder engines the use of a single eccentric with
an undivided ring having rods projecting from it for working the slide valves.
2. The use for each cylinder of a piston slide valve not subject to pressure, with
an internal auxiliary slide, both worked from one and the same eccentric rod.
3. The arrangement in each working piston of exhaust passages which are auto-
matically opened towards the end of the working stroke by the movement of the piston
itself thus dispensing with separate exhaust valves.
Dated this 5th day of October 1888.
ABEL & IMRAY,
Agents for the Applicant.