Improved Reversing Gear for Steam Engines.
Year: 1892

page_text: Date of Application, 3rd May, 1892-Accepted, 4th June, 1892
COMPLETE SPECIFICATION.
Improved Reversing Gear for Steam Engines.
I, ECKHARD DAMM, of Niedernstrasse 57, Hamburg in the Empire of Germany,
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 reversing gear for steam engines and is intended for
quickly and easily starting or stopping and reversing the direction of movement
of such engines and more especially of two-cylinder engines.
The invention consists in the combination of a rotary disk for regulating the
inlet of steam and direction of its flow, with a specially constructed slide valve or
slide valves for distributing the steam to the cylinder or cylinders.
The annexed drawing illustrates the invention as applied to a two-cylinder steam
engine, Fig. 1 being an elevation Fig. 2 a plan and Fig. 3 a part end elevation of
the engine with the slide boxes and valves in section. Figs. 4, 5, and 6 are detail
views.
A A are the two cylinders, B B¹ their respective slide boxes, and S S¹ the
slide valves therein. The slide boxes are in communication by pipes a a¹ and b
with the regulating device C which consists of the conical or flat plate D which
is revolvably journalled in contact with the surface E in which the aforesaid
pipes a a', bb connected in pairs have their orifices at I, II respectively and in
which the steam feed pipe and the exhaust pipe g also have their respective
orifices.
The plate D is provided with the grooves d and e and is pressed upon the
surface E by a spring w or in larger engines by any other suitable means so that
the plate D may be steam tight.
i, kare the inlet and outlet ports of the cylinders A A' each leading into
the respective valve box B B. Between these ports in each box is an annular
groove communicating with the pipe bor b' respectively. Each cylindrical slide
valve S S is provided with the lateral groove m and with the through passage n.
With the parts in the position shown in Figs. 1 to 3, the steam enters from
pipe passes through the recessed channel d in the plate D into the orifice I of
the pipes a a¹ and thus into the ends of the slide box B through the passage n into
the cylinder A through port i; the entrance into cylinder A¹ being for the moment
closed by the position of the slide S. The exhaust passes from the ports il and kl
into the grooves m of the slides S S¹ thence through grooves to the pipes 6 b¹
entering at II into the channel e in the plate D and thus into the exhaust pipe g.
Fig. 4 is a plan view of Figure 3. Figure 5 shows the parts reversed. The
plate D has been turned through a right angle and the steam now enters and
passes by channel e to orifice II of pipes bb', while the exhaust issues at I and
passes by channel d to the pipe g.
Figure 6 shows the intermediate position in which the inlet of steam at f is cut
off and at the same time each orifice I, II is simultaneously placed in communica-
tion with the exhaust g so that pressure is equalized in the cylinders of the engine.
The reversing is certain so that when the plate D is turned, into its reversing
position the engine cannot fail to operate in the opposite direction.
In applying the invention to a single cylinder engine it is necessary only to
dispense with one of the pairs of tubes a b or a¹ b¹ so that the orifices I and II lead
to pipes communicating only with one slide box as described.
The grooves and the passage n permit of having the slide valves S S¹ free
from unbalanced pressure.

page_text: Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
A reversing gear for steam engines consisting in the combination of a disk or
equivalent D having channels d and e and controlling the inlet and outlet to
orifices I and II respectively of pipes a a' b b', with one or more slide valves S S¹
with grooves m and passages n, and slide valve box or boxes B B' therefor with
portsikk, and grooves and connected to said pipes a ba¹ b' respectively as
described.
Dated this 2nd dox of Mov 1899
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.