Year: 1888

page_text: Date of Application, 9th Apr., 1888
Complete Specification Left, 9th Jan., 1889
Complete Specification Accepted, 23rd Feb., 1889
*300*7
We, ALEXANDER MAROKT of the firm of J. & E. Hall of 23 St. Swithins Lane
in the City of London Engineers and OLIVER JOCOLYNE ELLIS of 5 Mycence Road
Westcoomb Park, Blackheath in the County of Surrey Engineer do hereby declare the
nature of this Invention to be as follows:-
This Invention has for its principal object to provide means or appliances whereby
the compressed air of supply mains can be employed in the production of cold.
An apparatus constructed according to this Invention consists of an expansion
cylinder whose inlet pipe or passage is fitted to be attached to a branch from the com-
pressed air main the force exerted on the piston of the said expansion cylinder being
caused to do work by its piston rod being connected to a shaft or otherwise. The
inlet valve to the expansion cylinder may have a double edge for admitting the com-
pressed air and cutting it off preferably at both ends of the cylinder the said valve
being so made that the compressed air is admitted from both sides of the said double
edge the valve face of the chest having passages to correspond. This arrange-
ment gives twice the port area and twice the rapidity of cut off of a single edge
valve arranged in the usual way. The exhaust valve may consist of a double piston
valve one piston for each of the exhaust passages the said pistons working in corre-
sponding chambers with the exhaust outlet between. The pistons may be packed
by means of leather metal or other material which may be secured in place by a
gland or like arrangement. The exhaust chamber is preferably covered by one large
side cover which can be removed for readily clearing away ice or snow which may
form.
The work which it is necessary that the machine should do in order to enable Cold
to be produced may be the driving of machinery such as water pumps, dynamos or
air compressors. A small special cylinder may be arranged for this purpose or air or
other fluid may be compressed in the chambers in which the exhaust valves work the

page_text: compression being effected by the said valves. In order to govern the machine either
when it is doing useful outside work or when it is not doing useful work we may
provide on the shaft which the expansion cylinder piston drives wheels or pulleys one
of which may have the strap for useful work passed over it another having a friction
strap passed over it the said strap being tightened and loosened by a governor driven
by the apparatus so that when it is relieved of useful work the governor puts
on the brake to the requisite degree the governor being assisted if necessary by the
compressed air.
When a compression cylinder is used the valves thereof may each consist of an
annulus pressed upon the valve seat by a spring disc like a star or with notches cut
in its edge so that the projections between the notches act as blade springs for the
valves.

page_text: the Expansion or Compressed Air.
We, ALEXANDER MAROET Managing Director of J. & E. Hall Limited of 23 St.
Swithins Lane in the City of London Engineers and OLIVER JOCOLYNE ELLIS of 5
Mycenoo Road Westcoomb Park Blackheath in the County of Surrey, 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 has for its principal object to provide means or appliances whereby
the compressed air of supply mains can be employed in the production of cold.
An apparatus constructed according to this Invention consists of an expansion
cylinder to which the compressed air is led after preferably passing through a
dessicator or drying apparatus such as is described in the Specification of Letters Patent
No. 11241 dated 3rd September 1886 granted to Everard Hesketh. The air expands
against a piston the rod of which is connected to a shaft or to other working device
so that the air in expanding is caused to do work and consequently give up its
heat.
The expansion cylinder is provided with an inlet valve chest to which the compressed
air is led and which is fitted with an inlet valve having a double edge for admitting
and cutting off the supply of compressed air to the cylinder the said valve being so
made as to admit and cut off the air at both sides of the double edge the valve face
of the cylinder baving passages corresponding to the valve.
This arrangement gives twice the port area and twice the rapidity of cut off of a
single edge valve arranged in the usual way.
The cylinder is also provided with an exhaust valve chest tho exhaust valve
consisting of a double piston valve each piston of which acts in a cylinder forming
part of the exhaust passages at the ends of the cylinder and both discharging prefer-
ably into a common exhaust or cold air delivery chest between them from which the
cold air is led to the refrigerator chambers. This delivery chest is preferably fitted with
a door which can be removed for readily clearing away any ice or snow which may
form.
The work which it is necessary that the machine should do in order to enable cold
to be produced may be the driving of machinery such as water pumps or dynamos.
In such cases in order to keep constant the amount of work which the apparatus
must do in order to eliminate the heat from the air and therefore to discharge it at the
required temperature we may provide on the shaft which the expansion cylinder piston
drives wheels or pulleys one of which may have the strap for useful work passed over
it another having a friction strap passed over it the said strap being tightened and
loosened by a governor driven by the apparatus so that when it is in part or entirely
relieved of useful work the governor puts on the brake to the requisite degree to keep
the total amount of work constant the governor being assisted if necessary by the
compressed air. Any suitable form of brake may be used.

page_text: The expansion cylinder may be caused to compress air in a compression cylinder
arranged above it, the piston of which is secured to a prolongation of the piston rod
of the expansion cylinder, and thus do the necessary amount of work to cool the air
in providing a portion of the compressed air required for its own supply, or for any
other purpose, which air, after passing through tubular coolers surrounded with cold
water as is usual in cold air machines, may be led into the compressed air
main, passed through the dessicator and thence to the inlet valve chest of the expansion
cylinder.
In order that an air expansion machine fitted with a compression cylinder as
hereinbefore described may be used for other external work the compression cylinder
may be fitted with a balanced valve connecting the two ends of the cylinder the
position of which is regulated by a governor driven from the crank shaft and in such
a manner that when the governor is down owing to the speed of the machine being
reduced by additional external work the valve opens communication from end to end
of the compression cylinder so that the air instead of being discharged into the coolers
or pressure main is delivered into the opposite or suction end of the cylinder. This
reduces the work done on the air in the compression cylinder, and external work may
be performed by the machine as a motor to such an extent as to compensate for this
reduction. When the external work is not required the speed of the machine
increases, the governor rises and closes the communicating valve, and the compression
cylinder delivers all its air into the coolers or pressure main.
When a compression cylinder is used to absorb the work the valves thereof may
each consist of a ring pressed upon the valve seat, having an annular opening, by a
spring disc like a star or with notches cut in its edge so that the projections between
the notches act as blade springs for the valves. This valve is applicable to compression
cylinders generally.
And in order that our said invention may be fully understood we shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexod slicets of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 of the accompanying drawing shows in vertical section an apparatus for
use in connection with compressed air supply mains according to this Invention. A is
an expansion cylinder the inlet valve chest B of which is supplied with compressed air
by a branch from the compressed air main. The piston C of the said cylinder has its
rod c connected to a crank shaft E which is caused (by a strap passed over a pulley
on the said shaft for instance) to do any required work such as driving machinery or
the like. The inlet valve F of the said cylinder has a double edge ff at each of its
ends by which, as will be readily seen by the drawing, the compressed air is admitted
from and cut off by both sides of the said double edges of the valve. The exhaust
valve consists of two pistons G G one for each of the exhaust ports from the cylinder
and each working in corresponding chambers into which the exhaust ports open the
exhaust outlet being between the two pistons. The exhaust chamber is covered by a
side cover H by removing which the exhaust passages can be readily cleaned from
snow or there may be opposite each exhaust passage from the cylinder a door as at h
which can be removed for the purpose of clearing away snow to facilitate which
clearing the said passages are preferably in a right line as shown. Figure 2 shows a
similar arrangement to that in Figure 1 but with the employment of a compression
cylinder as aforesaid.
I is the compression cylinder its piston J being connected to the piston C of the
expansion cylinder by the rod j. Kis the aforesaid valve controlled by the governor L
as hereinbefore described to discharge the air either into the coolers or mains or to
pass it from one end of the cylinder to the other according to the speed of the engine
and consequent position of the governor.
In Figure 1 the hereinbefore mentioned brake is shown at M as consisting of
what is known as a Weston's friction brake it acting in the manner usual with such
brakes. Figure 3 shows a brake consisting of a strap N passing over a pulley P on
the crank shaft and applied and taken off by the governor Q.

page_text: Figure 4 shows separately in vertical section and Figure 5 in plan the improved
valves for the compression cylinder each consisting of a ring valve k closing upon
a valve seat having an annular opening the valve being guided and pressed
down by the blade springs m which are conveniently formed by the arms or rays of
the star shaped or notched disc secured respectively above and below the valves.
Theso valves are shown in position on the compression cylinder I in Figure 2.
A dessicator such for instance as is described in the Specification of Letters Patent
granted to Everard Hesketh No. 11241 dated 3rd September 1886 may with
advantage be placed in the branch between the aforesaid apparatus and the com-
pressed air main. It will be understood that although we have specially named
compressed air from supply mains yet that the apparatus may be used in cases where
the compressed air is derived from other source.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. In combination with mains supplying compressed air a branch leading there-
from and an expansion cylinder to which the said branch delivers compressed air and
means to which the piston of the said expansion cylinder is connected so that the
expansion of air in the said cylinder is caused to do work substantially as herein-
before described.
2. In combination with mains supplying compressed air or other source of supply
of compressed air a branch leading therefrom and an expansion cylinder to which
the said branch delivers compressed air and means to which the piston of the said
expansion cylinder is connected so that the expansion of air in the said cylinder is
caused to do work and a brake under control of a governor driven by the apparatus
substantially as and for the purpose hereinbefore described.
3. In connection with mains or other source supplying compressed air a branch
leading to an expansion cylinder having a double edged inlet valve for the purpose
described and having its piston connected to means whereby the air expanding in
the cylinder is caused to do work substantially as herein before described.
4. The several arrangements and combinations of apparatus for use in connection
with mains or other sources supplying compressed air substantially as hereinbefore
described and severally illustrated in Figures 1 and 2 of the accompanying
drawings.
5. In apparatus for the production of cold by the expansion of compressed air, a
valve or valves for the compression cylinder the said valve or valves each consisting
of a ring pressed upon the valve seat (and controlling an annular opening) by a
series of blade springs or spring disc which is star shaped or has notches cut in its
edge substantially as hereinbefore described and illustrated in Figures 4 and 5 of the
accompanying drawings.