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1. * GB780192 (A)
Description: GB780192 (A) ? 1957-07-31
Improvements in or relating to inside-steam piston-type engine slide valves
Description of GB780192 (A)
PATENT SPECIFICATION
7S 0,192 4' Date of Application and filing Complete Specification:
March 30, 1954.
No. 92561J54.
Complete Specification Published: July 31, 1957.
Index at acceptance:-Class 122(2), BI6D1B.
International Ctassification:-FOlf.
COMPLETE SPECIFICATION
Improvements in or relating to Inside-Steam Piston-Type Engine Slide
Valves I, CURT GARuE, Sen., a German National, of 44,
Fanningerstrasse, Berlin-Lichtenberg, Germany, do hereby declare the
invention, for which 1 pray that a patent may be granted to me, and
the method by which it is to be performed, to be particularly
described in and by the following statement:-
The two end spaces of the engine cylinders of locomotives having
piston type slide valves, particularly superheated steam locomotives,
when running idle, are pressure equalised by coasting devices mostly
working with compressed air. In other constructions a free equalizing
communication is established directly through the flue across the
outlet ports. This is detrimental owing to the fluegases being
absorbed, the gases, pressed through the cylinders, with their
abrasive contaminants causing an excessive cylinderwear.
The object of the invention is to effect the pressure equilibrium
within the slide valve itself. The communication between the spaces in
front of and behind the working piston thus is not made through the
outlet ports and over the flue but directly across the steam chamber
of the slide valve itself which ensures a longer life of the sliding
parts and freedom of the respective component parts from abrasive
smoke-deposits.

2. According to the present invention there is provided an inside-steam
piston-type engine slide valve comprising at least two groups of
piston rings on either head thereof arranged near the steam
controlling edges wherein each head carrying the piston rings consists
of two separate components which are normally tightly held together
under the pressure of the incoming steam, but which, on idling of the
engine, are separated by a spring located between these two components
so that the ports of both cylinder end spaces are then put into
communication with the slide valve steam chamber by apertures
extending through each of the inner of said components.
The drawing shows the invention by way [Price 3s. 6d.] of example,
namely in longitudinal section through an inside-steam piston-type
slide valve, the upper half showing the valve parts in position when
steam pressure is present 50 and the lower half showing the parts when
relieved of steam pressure.
The piston valve rod carries two sets of valve components. As these
sets are of the same design, one set only will be described. 55 The
annular valve parts or heads consist of the separate components E and
F, each carrying groups of piston rings A and B near the steam
controlling edges C and D which are provided on either side of the
slide valve. 60 When the steam enters the steam chamber the two
components are tightly 'pressed together, as indicated in the upper
portion of the drawing. The pressure of the steam acts on the annular
area provided between the 65 periphery of the inner piston-valve
component F and the sealing surface between the piston-valve
components. With the steam shut-off, i.e. when running idle, the two
component parts E and F, by means of the interlocated spring G, are
moved apart and the valve becomes as indicated in the lower portion of
the drawing. The pressure equilibrium is now established across ports
H and J for each end of the cylinder and across the 75 apertures K of
the inner component F with the slide-valve steam chamber.
The device has been designed with a view to securing a full pressure
for holding the two component parts of the valve together even 80 with
a high rate of cut-off, by dimensioning the above-mentioned annular
area sufficiently large. The spring G is strong enough to hold the
body of the valve in neutral position when idling to avoid any
knocking even at high 85 speeds and in spite of forces exerted by the
reciprocating masses.
Lubrication can be effected in a known manner as with slide valves and
by means of the ordinary lubricating holes. 90 In the embodiment
illustrated in the drawing the component parts E have annular
seal780,192 ing surfaces projecting inwardly from their inner surfaces
with which co-operate annular sealing surfaces projecting outwardly
from the outer surfaces of the component parts F, these co-operating

3. sealing surfaces being shown in engagement in the upper part of the
drawing and out of engagement in the lower part of the drawing.
The cylinder having a port H or J at each end thereof may be a
cylinder of a locomotive and have arranged therein a piston each side
of which is connected to a respective port H or J so that the
piston-type slide valve controls the reciprocatory motion of the
piston in the cylinder. The piston may be sealed against the
locomotive cylinder wall in any customary manner, for example by means
of a labyrinth packing.
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* 5.8.23.4; 93p