Improvements in Variable Expansion Valve Gear for Steam Engines.
Year: 1890

page_text: Date of Application, 24th July, 1890
Complete Specification Left, 24th Apr., 1891--Accepted, 6th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in Variable Expansion Valve Gear for Steam Engines.
I, ALFRED GUHRAUER of Budapest in the Empire of Austria Hungary,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to steam distributing-regulators and has for its purpose
to render the action of the regulator independent of the slide pressure, so as to
allow of a regulation of greatest precision.
"
The inlet ports of the distributing slide branch off upwardly into three, or
another number of, canals terminating on the back of the slide in a cavity or bed
for a "Corliss
slide which is provided with a corresponding number of canals
and forms, with its shaft lodged in the sides of the distributing slide, part of the
latter and consequently follows the movements of the same. The extremities of
said shaft carry secured thereto, peculiarly shaped two-armed levers. On the sides
of the distributing slide lie plates provided on both sides with steel teeth. When
the distributing slide moves, said plates being supposed to be stationary, an edge
or projection of each of said levers abuts against the respective stationary tooth
whereby the shaft and "Corliss" slide are turned, and the canals of the distributing
slide are closed. By said movement the other arm of the lever has been turned so
far down as to occupy a horizontal position and be consequently enabled to move
on underneath the tooth without altering its relative position. On the return
movement of the distributing slide, the re-opening of the canals takes place in an
analogous manner.
The transmission of movement may be effected in any suitable manner but
preferably by means of two right- and left-worms secured on the revolving shaft
and gearing into screw threads provided on the plates referred to, whereby these
plates are shifted apart by the revolution of the shaft and consequently the
initiatory period of action of the teeth, and thereby the filling, is altered. The
plates may also, instead of being stationary, be actuated by separate excentric
movement.
Also the "Corliss" slide may be replaced by horizontal broken-through plates,
conic or flat circular slides with radial apertures or by any expansion slides of
suitable shape having a canal or canals.
Dated this 24th of July 1890.
HUELSER & Co.,
Attorneys.
COMPLETE SPECIFICATION.
Improvements in Variable Expansion Valve Gear for Steam Engines.
I, ALFRED GUHRAUER, of Budapest in the Empire of Austria-Hungary,
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 :-
In double slide valve gear for steam engines, the variations of the supply take place
by altering the relative positions of the expansion slide plates. The endeavours
to carry out these variations automatically by means of the regulator fail from the
circumstance that the friction of the valves, which has to be overcome by the
regulator, is so great that the regulator cannot overcome the same with sufficient
precision, and, consequently, the variation of the number of revolutions becomes
too great.

page_text: :
This invention relates to variable expansion valve gear, and has for its purpose
to render the action of the regulator in such gear independent of the slide
pressure so as to allow of the parts being regulated with the greatest precision.
Reference being had to the accompanying sheet of drawings, and to the figures
and letters of reference marked thereon,
Figure 1 is a longitudinal elevation, half in section, of a valve with the improved
variable expansion gear applied thereto.
Figure 2 is a section on the line xx of Figure 1.
Figure 3 is a plan view of the distributing slide plate g hereinafter referred to.
Figures 4" to 4" are views showing the different positions of the levers ff¹ herein-
after referred to.
Figures 5, 6 and 7 are slight variations, hereinafter referred to, of the invention.
In Figures 1 and 2 on the annexed drawing :-
A, is the distributing slide valve. Each of the inlet ports b of the same branch
off upwardly into three or another number of ports c c c, the upper parts of which
form a cavity or bed for a "Corliss "slide d, which is provided with a corresponding
number of ports c¹ c¹ c', and forms, with its shaft e lodged in the sides of the
distributing slide valve, port of the latter, and, consequently, follows the movements
of the same.
The extremities of said shaft e carry secured thereto peculiarly
shaped levers ff. On the sides 11 of the distributing slide valve lie plates 9 9,
provided on both sides with steel teeth h, Figure 3.
Referring to Figure 4* :-
"
When the distributing slide valve moves, said plates 9 g being supposed to be
stationary, an edge or projection u of each of said levers fabuts against the
respective stationary tooth i, Figure 4b, whereby the shaft and "Corliss slide
,attached thereon are turned and thus the ports ccc of the distributing slide valve
are closed. By said movement, the other arm of the lever has been turned so
far down as to occupy a horizontal position, Figure 4°, and be consequently enabled
to move on underneath the tooth i without altering its relative position. Its
position is thereby fixed. On the return movement of the distributing slide valve,
Figure 4d, the lever f¹ is turned upwards, and the ports c c c are re-opened.
The transmission of the movement of the regulator may be effected in any
suitable manner, but preferably by means of two right and left hand worms
secured on the revolving shaft o and gearing into screw threads r, provided on the
plates 99 referred to, whereby these plates g g are shifted apart by the revolution
of the shaft o, and, consequently, the initiatory period of action of the teeth h and
thereby the supply is altered. A. small amount of power suffices for revolving
the shaft o and the separation of the plates g g as the plates are encompassed on
all sides with steam, and thus have only slight friction. The separation of the
plates 9 9 can take place in any other suitable manner. The plates 9 g may also,
instead of being stationary, be actuated by separate eccentric movement without
altering anything in the essence of the invention. The above described principle
allows of numerous variations.
Also the "Corliss" slide may be replaced by horizontal perforated plates,
Figure 5, t ; conical, Figure 6, t' t'; or flat circular slides, Figure 7, t t, with
radial apertures or by any expansion slides of suitable shape having a canal or
canals.
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 :-
1. The improvements in variable expansion valve gear for steam engines
consisting in the application, to the back of the valve, of a fixed shaft e having
levers in combination with a plate 9 having teeth i (such plate being capable
of adjustment), said parts being arranged and working together substantially as and
for the purposes hereinbefore described and shown.
2. In variable expansion valve gear of the kind set forth in Claim 1, the means

page_text: for controlling the movement of the regulator plate, consisting of a revolving
shaft o having worms, and the screw-threads r on the back of the regulator plate
into which the worms engage, arranged and working substantially as hereinbefore
described and shown.
3. The general arrangement and construction of the variable expansion valve
gear in its entirety substantially as hereinbefore described and shown.
Dated this 23rd day of April 1891.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.