Improvements in Inter-convertible Air-motors and Compressors.
Year: 1899

page_text: Date of Application, 3rd Oct., 1899-Accepted, 3rd Feb., 1900
COMPLETE SPECIFICATION.
Improvements in Inter-convertible Air-motors and Compressors.
We, BENJAMIN SMITH LAWSON, Asa Lanfear MeRRICK, EUGENE MONTGOMERY
MERRICK, and ANDREW J. DEMOTT, all of Syracuse, in the County of Onondaga.
and State of New York, United States of America, Gentlemen, 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 improvements in convertible air motors and com-
pressors, and the object is to provide a device of this character which may be used
as a motor, and as occasion requires, may be converted into a compressor, and
vice versa.
To this end the invention consists in the construction, combination and arrange-
ment of the several parts of the device as will be hereinafter more fully described
and particularly pointed out in the claims.
.
In the accompanying drawings the same reference characters indicate the same
parts of the invention.
Fig. 1 is a longitudinal section of an air cylinder and valve mechanism embody-
ing the invention.
Fig. 2 is a vertical transverse section on the broken line 2-2 of Fig. 1.
Fig. 3 is
similar view on the broken line 3-3 of Fig. 1.
I denotes the cylinder, 2 the piston and 3 the piston-rod; 4 denotes the valve
chest and 5 the slide valve which is a modified form of the ordinary D valve
and its inner face is formed with a socket G to receive the free end of a crank arm 7,
mounted on a packed rock-shaft 8 journaled in the cylinder wall, and the project-
ing end of said rock-shaft is connected in the usual manner to the link-motion"
operated by the eccentrics carried by the crank shaft. We do not deem it neces-
sary to show the crank shaft, the "link motion" reversing gear or the connection
between the piston rod and said crank shaft, as these parts are of the conventional
style and form no part of this invention.
9 denotes the inlet pipe connecting the chest 4 with the pressure storage tank
(not shown).
10 and 12 denote the cylinder inlet ports and 13 the exhaust port, extending
from the valve seat 14 part way around the cylinder and communicating with a
longitudinal jacket-port 15, which has an orifice 16 opening into the atmosphere.
The forward end of the longitudinal port. 15 communicates with a valve chamber
17, in which is mounted a spring-actuated valve 18, and the said chamber com-
municates with the front end of the cylinder by means of the short port 19.
The rear end of the longitudinal port 15 also communicates with a valve
chamber 20, in which is located a spring-actuated valve 21, and the said chamber
communicates with the rear end of the cylinder by means of the short port 22,
and both of these valves open inwardly with respect to the cylinder.
The forward inlet port 10, extends from the valve seat 14, to the forward end of
the cylinder and the rear inlet port 12 extends from said valve seat to the rear
end of the cylinder.
'
25 and 26 denote." one way" plug cocks, mounted in the walls of the inlet

page_text: ports 10 and 12 respectively, and their projecting stems are provided with the
crank arms 27-27 which in turn are connected by a rod 28, for operating said
plug cocks, so as to simultaneously open or close said ports for a purpose to be
presently explained.
29 and 30 denote short lateral ports connecting the main ports 10 and 12
respectively with the interior of the valve chest 4, and the upper ends of these
lateral ports are normally closed by the outwardly opening spring-actuated
valves 31 and 32.
This completes the description of the working parts and we will now proceed
to describe the operation.
23
The parts. being in the position shown in Figure 1 with the plug cocks "open
and the slide valve in position to take air to the forward end of the cylinder, the
inner face of the valve allows the air in the back of the cylinder to escape through
the port 12 into the exhaust port 13 and from thence through the orifice 16 into
the atmosphere. This arrangement constitutes the well known form of recipro-
cating slide valve engine.
When it is desired to convert the device into a compressor, it is only necessary
to shift the rod 28 to close both plug cocks 25 and 26, which of course closes the
port-passages 10 and 12, so that as the piston moves forward the air in the
cylinder ahead of the piston is forced through the outer end of the port 10 and
short port 29, lifting the valve 31 and passing into the valve chest 4 whence it is
stored into the tank through the inlet pipe 9.
In the meantime while the piston is moving forward as above described, the
air is entering the cylinder behind the piston through the valve 21, and when
said piston has arrived at the forward end of its stroke, and starts on its rearward
movement, the valves 31 and 21 close, the air ahead of the piston is forced
through the valve 32 into the tank, and air is taken into the cylinder behind
the piston through the inlet valve 18. Of course it will be understood that
when the cylinder is in use as an air compressor, the slide valve continues its
reciprocating movement as usual, but is functionless, due to the plug valves
obstructing the ports 10 and 12.
This device is principally intended as a street car motor, the car starting out
with an initial pressure in the storage tank, which being applied to the cylinder as
a motor (the piston rod being properly geared to the car axle) impels the car on
level grade and when it is desired to stop it, or when on down grades, the plug
cocks 25 and 26 are closed and the momentum of the car being transmitted to
the piston, converts the cylinder into an air compressor and thereby restores or
returns a portion of the spent air pressure to the tank, and while we have given
this illustration as one of the uses of such a device, it is evident that it is
susceptible of various other applications and in this connection it may be stated
that we do not desire to confine ourselves to the precise construction shown, as
various modifications, such as would fall within the scope of this invention, will
readily suggest themselves to those skilled in this art, without departing from
the spirit of the invention as hereinafter claimed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what
we claim is:-
1. A cylinder provided with main inlet and exhaust ports, and independent
valved inlet ports opening into the atmosphere, a valve chest and valved branch
ports connecting the cylinder ends of said main inlet ports with said chest and
means for simultaneously interrupting communication between the opposite ends
of each main inlet port, substantially as and for the purpose set forth.
2. A cylinder provided with the usual main inlet and exhaust ports and having
independent valved inlet ports communicating with said exhaust port, a valve chest
and independent valved branch ports connecting said chest and cylinder and
means for simultaneously cutting off communication between said branch ports

page_text: and the inlet ends of said main inlet ports, substantially as and for the purpose
set forth.
3. A cylinder provided with main inlet and exhaust ports, and auxiliary valved
inlet ports, a valve chest and a slide valve mounted therein, independent valved
branch-ports connecting said main inlet ports and chest, and the plug cocks
mounted in said main inlet ports, substantially as and for the purpose set forth.
4. The cylinder provided with the usual inlet ports 10 and 12, the usual exhaust
port 13 and the independent valved inlet ports 19-15 and 22-15 connecting the
opposite ends of said cylinder with the atmosphere, the valve chest 4, the valved
branch ports 29 and 30 and the intercepting plug cocks 25 and 26 located in
the main inlet ports 10 and 12 respectively, substantially as and for the purpose
set forth.
TY L
1
1
1000
BOULT, WADE & KILBURN,
Agents for the Applicants.