Improvements in and connected with Slide Valves for Motive Power Engines.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Slide Valves for Motive Power
Engines.
I, HORST GÖHLER of Humboltstr. Freiberg i/Sachsen in the German Empire,
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:-
This invention relates to an expansion slide valve mechanism for motive power
engines driven by compressed air, gas, or steam which valve mechanism is located
in the working piston of the engine which it operates.
In the drawing
Figs. 1 and 2 shew a slide valve arrangement of this invention in longitudinal
section. Fig. 3 a cross section thereof. Fig. 4 is a side view. Figs. 5, 6, 7 refer
to details.
a is the cylinder, 6 the working piston formed with a recess c in which is arranged
a main slide d somewhat shorter than the length of recess c and the top surface of
which stands in, somewhat from the periphery of the piston so that between the
wall of the cylinder a and the main slide d there is a space e in which works an
expansion slide f suitable for the main slide and also corresponding to the bore of
the cylinder. The main slide d is provided at each end with a shoulder g, g², which
limit the travel of the expansion slide.
The distribution of the driving medium, steam for instance, takes place in the
following manner-Taking the piston to be in the end position of Fig. 1, steam is
admitted through pipe first displacing expansion slide from its position in Fig. 1
to the position of Fig. 2, that is, to strike against the shoulder and then after
accomplishing this displacing by means of the expansion slide the main slide from
the position of Fig. 1 to that of Fig. 2 so that at the front end of recess c there is
uncovered a port in the piston which port goes right through to the rear side
thereof to which the steam then passes and expanding, drives the piston to the
other end of the cylinder that is to say, from the position of Figs. 1 and 2 to that
of Fig. 4. In this position, the expansion slide f, in the same manner as before, is
first driven from the shoulder g to the shoulder g' of the main slide d whereupon
this latter is again carried along by means of the expansion slide so as thereby to
uncover a port in the piston which port (in a similar manner to port i) goes right
through to the front side of the piston to which the steam passes driving it from
the position of Fig. 4 back again into the position of Figs. 1 and 2 and so on.
exhaust steam or other driving medium passes, after the corresponding piston
stroke, through one of the passages i or each of which alternately places the
main slide d in communication with a radial passage j formed in the piston through
which the exhaust steam passes into and through a recess k and thence through an
orifice in the cylinder to the atmosphere. As the expansion slide f on the main
slide d shuts off the admission through orifice h of the driving medium previous to
the completion of each stroke of the piston, an expansion of the said medium can
consequently take place, such expansion commencing the sooner, the greater the
length of the expansion slide.
The
This slide valve mechanism has stood the test of trials exceedingly well,
8000 revolutions per minute having been obtained which number it is conjectured
may with a correspondingly increased pressure of the driving medium be increased
up to about 20.000.

page_text: 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 :-
An expansion slide valve mechanism for motive power engines, comprising a
main slide sliding in a recess in the working piston and alternately opening and
shutting off ports i, i, for the driving medium; and an expansion slide sliding
on the main slide and in its displacement thereon by the driving medium striking
or bearing alternately against a shoulder g or g¹ on the main slide so as to carry
the main slide with it thereby opening a passage for the driving medium to one or
the other side of the working piston, said expansion slide in the travel of the piston
shutting off the driving medium from the cylinder carlier or later according to the
length of the said expansion slide, substantially as described and shewn.
Dated this 18th day of February 1893.
THOMAS R. SHILLITO,
89, Chancery Lane, London, W.C., Agent for the Applicant.