Improvements in and relating to Refrigerating Machines.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Refrigerating Machines.
A communication from abroad by ALBERT TISDALE MARSHALL, of 157, Highland
Street, Brockton, in the County of Plymouth, State of Massachusetts, United
States of America, Engineer.
I, REGINALD WILLIAM JAMES, of the Firm of Fell and James, of 1, Queen
Victoria Street, London, E.C., Chartered Patent Agents, 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 that class of refrigerating machines, which ordinarily
employ anhydrous ammonia as a refrigerating medium, and the objects of this
invention are, first, to provide means for automatically regulating the admission
of the refrigerating medium to the expansion pipes or chambers; second, to
provide an improved form of hand shut-off valve for the ammonia pipes; third,
to provide an improved form of thermostatic regulator for controlling the motor
which drives the pump, so that the pump will be actuated to maintain a constant
temperature in the refrigerated space; and, fourth, to provide means for auto-
matically regulating the circulation of water employed for cooling the refrigerat-
ing medium.
To these ends this invention consists of the parts and combinations of parts, as
hereinafter described, and more particularly pointed out in the claims at the end
of this specification.
In the accompanying seven sheets of drawings,
Fig. 1 is a transverse, sectional view of a refrigerating apparatus constructed
according to this invention, the water circulating pipes being omitted,
Fig. 2 is a longitudinal sectional view of the same,
Fig. 3 is a diagramatic view illustrating the electrical connections preferably
employed for the combined thermostat and rheostat which controls the motor
which actuates the pump,
Fig. 4 is a perspective view of the combined theremostat and rheostat,
Fig. 5 is a diagramatic view thereof,
Figs. 6, 7, 8, and 9 are detail views thereof,
Fig. 10 is a detail sectional view illustrating one form of automatic valve which
may be employed for regulating the admission of the refrigerating medium to
the expansion pipes,
Fig. 11 is a detail sectional view illustrating a form of hand shut-off valve
which may be employed,
ג
Fig. 12 is a detail view of the construction employed for controlling the water
circulation,
Fig. 13 is a detail view of a safety cut-out for stopping the pump when the
supply of water is cut off,
Fig. 14 is a detail sectional view of a modified form of automatic valve for
regulating the admission of the refrigerating medium to the expansion.pipes,

page_text: Fig. 15 is a diagramatic view showing the connections between this form of
automatic valve and the other parts of a refrigerating apparatus, and
Figs. 16, 17, 18, 19 and 20 are detail views illustrating the construction of
said automatic valve.
A refrigerating apparatus constructed according to this invention comprises a
storage chamber for liquid anhydrous ammonia or other refrigerating medium,
the expansion pipes or coils in which the liquid ammonia is allowed to expand
into the form of a. gas, a pump for drawing the refrigerating medium from the
expansion pipes' and condensing it back to a liquid, and connections so that the
medium will be cooled preferably by means of a circulation of water.
The expansion pipes or coils are preferably immersed in a brine-tank, but, if
desired, the brine-tank may be omitted, and the expansion pipes or coils alone
may be located directly in the space to be refrigerated.
These parts may be of any of the ordinary or approved constructions, and,
while the accompanying drawings, illustrate this invention applied to a com-
paratively small cabinet refrigerator or chest, it is to be understood that this
invention is equally applicable to the larger forms of ice or refrigerating machines.
To control the admission of refrigerating medium to the expansion pipes, it
is preferred to employ a needle valve for throttling or regulating the flow of the
expansion medium, and to automatically operate said needle-valve by the com-
bined action of the pressure of the expansion medium on the suction side of the
pump, and by the pressure of a body of expansion medium confined in a closed
vessel.
The hand-actuated shut-off valves, which may be employed at various points
in the ammonia circulating pipes, are preferably provided with diaphragms
which may be screwed down into engagement with suitable valve-seats. In
practice it is preferred to drive the pump by means of an electric motor, and in
order to maintain a constant temperature in the refrigerated space, to control the
electric motor by means of a combined thermostat and rheostat.
To cool the condensed refrigerating medium, a circulation of water is preferably
employed, and the admission of water to the cooling chamber is preferably con-
trolled by means of a needle-valve, which is automatically actuated by a dia-
phragm controlled by the pressure of the refrigerating medium.
If the supply of water should fail, or should be shut off, and the pump should
continue in action, a heavy pressure might be generated in the condensing coil.
and, in order to prevent this from happening, a safety cut-out device may be
used for stopping the motor when the water supply is shut off.
Referring to the first two sheets of drawings and in detail, A designates any of
the ordinary or approved forms of casing, which, as illustrated, is divided into
compartments B and C, the compartment C being the space which is to be
refrigerated, and the compartment B being arranged to contain the greater part
of the refrigerating apparatus.
Mounted in the rear part of the space C to be refrigerated is a flat, rectangular
brine-tank 10 containing the expansion pipes or coils 11.
The outlet pipe 12 from the expansion coils 11 is connected to a header 13.
A shut-off valve is arranged in the upper part of the header 13. and leading
from said header 13 is a pipe 14 connected to a pressure guage G, a pipe 15
which connects to one of the diaphragm chambers which control the expansion
valve regulating the admission of refrigerating medium to the expansion pipes 11.
and a pipe 16 which is connected to the suction side of a pump or condenser 17.
The pump 17 may be driven in any of the ordinary or preferred manners, and..
as illustrated, the same is preferably driven by a belt 18 from an electric motor 19
secured on top of the casing A,
The pressure side of the pump 17 is connected by a pipe 20 to a header 21:
Leading from the header 21 is a pipe 22 connected to a diaphragm chamber 23.
which contains the diaphragm for automatically controlling the circulation of
water in the cooling chamber, a pipe 24 which leads up to a second pressure

page_text: guage G, and a pipe 240, which leads down to a coil located in the cooling
chamber 25.
The header 21 may be provided at one end with an ammonia shut-off valve.
From the coil or worm in the cooling chamber 25, the condensed refrigerating
medium passes into a storage tank or chamber 26.
The tank 26 is provided at its end with a head 27, having an ammonia shut-off
valve.
Leading from the head 27 is a filling or blow-off pipe 28, which is closed at its
end by means of another one of the ammonia shut-off valves.
Also leading up from the head 27 is a pipe 29, which connects to the expansion
valve 30.
Leading from the expansion valve 30 is a pipe 31, which connects to the inlet
side of the expansion coil 11.
In the operation of a refrigerating apparatus, as thus constructed, the ammonia
or other refrigerating medium will be drawn by the pump 17 from the expansion
pipes 11 in the form of a gas, and will be condensed in the cooling chamber 25
to a liquid.
The circulation of water around the coil inside of the cooling tank 25 will be
automatically controlled, as hereinafter explained.
From the storage tank 26, the ammonia or other refrigerating medium will pass
in the form of a liquid to the expansion valve 30, said expansion valve 30 being,
as hereinafter explained, automatically controlled to regulate the admission of the
refrigerating medium to the expansion pipes 11 where the ammonia will expand
into the form of a gas, and cool the brine in the tank 10.
One construction which may be employed for automatically operating the
expansion valve 50 is most clearly illustrated in sheets 1, 2 and 5.
As shown on sheets 1 and 2, a shelf I is located near the upper part of the
compartment B.
Secured on the under side of the shelf I are the two diaphragm chambers 35
and 36.
The pipe 15, before referred to, is connected to the diaphragm chamber 35.
A small closed pipe or vessel H is located in the brine tank, and is provided
with a blow-off valve or header h by means of which liquid anhydrous ammonia
or other expansible medium can be introduced therein.
The pipe H connects to the diaphragm chamber 36. The construction of the
diaphragm chambers 35 and 36 and the connections for operating the valve 30
are most clearly illustrated on sheet 5.
"
As shown in Fig. 10, the diaphragm chamber 35 is formed by two castings 37
and 38.
Clamped in position between the castings 37 and 38 is a flexible rubber
diaphragm 39.
Below the flexible diaphragm 39, in position to be actuated thereby is a
follower 40, which is provided with a socket for receiving a stud 41, said stud 41
being pivotally connected at its lower end to a lever 42.
In order to form a tight joint between the pipe 15 and the casting 37, a
wrought-iron washer 43 is threaded on to the end of the pipe h, and a rubber
packing washer 44 is arranged between the wrought-iron washer 43 and a
bushing 45 threaded into the casting 37.
This form of connection has been found in practice to afford a very simple and
inexpensive manner of connecting an ammonia pipe to a valve-casing or casting,
and similar connections are preferably employed wherever an ammonia pipe is to
be tapped into or connected with other fittings or castings.
The diaphragm casing 36 is formed by the castings 47 and 48, which are of
similar form to the castings 37 and 38, and enclose a flexible diaphragm 49, said
diaphragm 49 being arranged to act upon a follower 135, which contains a
stud 136 also pivotally connected to the lever 42..

page_text: The lever 42 is pivotally mounted upon a bolt or stud 137, which bolt 137 is
adjustably mounted in a slot in the bracket 138, and passes through the slot 139
in the lever 42.
By adjusting the bolt or stud 137 in its bracket 138, the leverage exerted by
the diaphragms 4 and 39 can be readily and quickly adjusted.
The lever 42 is provided at its end with a handle 140, as shown in Fig. 1.
The expansion valve 30 is provided with a valve-stem 330 having a needle or
shut-off section 34 for controlling or throttling the flow of the refrigerating
medium.
The valve-stem 330 extends up through a suitable stuffing-box 141, and is
pivotally connected at its upper end to the lever 42.
In the operation of this construction for automatically controlling the expansion
valve, as thus arranged, the anhydrous ammonia, or other expansive medium
contained in the closed pipe or chamber H will exert a pressure on the
diaphragm 49.
If the temperature of the brine in the brine-tank 10 rises, the pressure in the
closed pipe or chamber H will increase, and the action of the diaphragm 49 will
tend to open the expansion valve 30 more widely so as to admit an increased
supply of the refrigerating medium to the expansion pipes 11.
Instead of immersing the pipe or chamber H in the brine-tank, it is obvious
that the same may be simply located in the space to be refrigerated, but in all
cases the expansion coil 11 and the closed coil or chamber H should have their
external surfaces exposed to the same temperature.
The pressure in the expansion coil 11 is transmitted through the pipe 15 to
act on the flexible diaphragm 39, and when the said pressure becomes abnormally
heavy, it will tend to close the expansion valve 30.
By changing the position of the pivot of the lever 42, a given pressure in the
closed pipe or chamber H may be made to balance any desired pressure in the
expansion coil 11.
The pressure of the ammonia or other expanding agent in the expanding coil 11
and in the closed pipe or chamber H depend directly upon their temperatures, and
consequently any desired difference of temperature can be maintained between
the refrigerating medium in the expansion coils and the expansion medium in
the closed pipe or chamber H while the pump is working.
Whenever the pump stops, the pressure in the expansion coil 11 soon rises to
that maintained in the closed pipe or chamber H, and the pivot of the lever 42
is so adjusted that this rise in temperature, and consequent rise in pressure will
always be sufficient to close the expansion valve, and the expansion valve will
remain closed until the pump has been started and has run long enough to reduce
the pressure in the expansion coil to the difference for which it was set, and, as
the pump continues to run, the pressure in the expansion coil 11 gradually falls,
as the brine cools.
As thus arranged, the expansion valve will be automatically operated in pre-
cisely the same way that an expansion valve would be worked by hand to obtain
the best results, that is to say, the expansion valve is always closed when the
pressures in the two coils are alike, regardless of the temperature of the brine-
tank.
In order to prevent the valve-stem 330 of the expansion valve 30 from becoming
stuck in place, the expansion valve may be occasionally flushed out by operating
the handle 140.
In some cases instead of using two diaphragms for controlling the expansion
valve, a single diaphragm may be employed, and such a construction is illustrated
on sheet 7.
As shown on this sheet, the automatic regulator R comprises a casing, formed
by the castings 140 and 150, which are clamped together by bolts 170 so as to
secure a flexible diaphragm 160 in place between said castings.

page_text: On the under side of the diaphragm is a disk 180 having a threaded spindle
extending up through the diaphragm.
A nut or washer 190 is threaded on to the spindle of the disk 180, and also
threaded on to the spindle of the disk 180 so as to form a check-nut for the
collar 190 is a slotted tube 200.
Coiled around the slotted tube 200 is a spring 210 which is confined at its
upper end by a collar 220.
Mounted inside of the slotted tube 200 is a nut 240 having arms, which extend
threaded on to the spindle of the disk 180 so as to form a check-nut for the
lower end of the coiled spring 210.
As shown most clearly in Fig. 19, the nut 240 is slabbed or cut away on
diagonally opposite sides, so that it can be readily introduced into the tube 200
in position to have its arms extended through the slots thereof.
An adjusting screw 250 is threaded into the nut 240 and extends up through a
stuffing-box to the outside of the casing, the upper end of the bolt being squared
so that it can be readily turned or adjusted by a suitable handle or wrench, when
desired.
Adjustably threaded into the disk 180 on the under side of the diaphragm 160
is the expansion valve-stem 260.
The valve-stem 260 carries a valve 350 co-operating with a valve-seat 360.
At its lower end, below the valve, the stem 260 is squared or made polygonal,
and engages a corresponding socket in a locking-sleeve 280, said sleeve being
held from turning by means of a pin 290, and being supported in place by a
cap 340.
A thermostatic receptacle or pipe H is connected to the upper casting 140 of
the casing, and, as most clearly shown in Fig. 15, the thermostatic pipe is
preferably carried through the brine-tank or compartment being refrigerated by
the expansion coil 11 so as to be exposed to exactly the same temperature to
which the expansion coil is exposed.
A quantity of the anhydrous ammonia or other refrigerating medium can be
admitted to the upper part of the casing of the regulator and to the thermostatic
pipe H through a by-pass 310 controlled by a valve 320.
The by-pass 310 is located entirely within the castings forming the casing of
the regulator, and extends up through the diaphragm 160.
In order to prevent the by-pass 310 from being closed by the compression of
the diaphragm 160 when the clamping-holts 170 are tightened, a small bush-
ing 330 is preferably located in a socket in the casting 140, as shown in Fig. 14.
In adjusting and operating the regulator, as thus constructed, the adjusting
screw 250 may be turned so as to bring its nut 240 to the bottom of the slot in
the tube 200 to positively open the expansion valve, thus allowing an unrestricted
flow of the refrigerating medium through the circulating pipes 10 and 11.
The valve 320 may then be opened to admit a quantity of the expansion
medium to the upper part of the casing of the regulator and the thermostatic
pipe H.
The valve 320 is then closed, and, as the thermostatic pipe H is exposed to the
same temperature as the expansion coil 11, the pressure in the expansion coil will
exactly balance the thermostatic pressure.
The pump or compressor is then started, and the adjusting screw 250 is turned
to raise its nut 240, and place the coiled spring 210 under tension tending to
close the expansion valve.
By means of this construction, it will be seen that the action of the expansion
valve may be controlled in exactly the same manner as by the construction first
described.
The form of shut-off valve which may be employed at various points in the
ammonia circulating system is most clearly illustrated in Fig. 11.

page_text: As shown in this figure, the ammonia shut-off valve comprises a casing 50
having an inlet passage 51 leading to a valve-seat 52, and an outlet passage 520.
Threaded on to the casing 50 is a cover-plate 53, and secured in place by the
cover-plate 53 is a compound diaphragm comprising a flexible metallic dia-
phragm 54, and a rubber diaphragm 55.
Threaded into the cover-plate 53 is an operating screw 57, which engages a
washer 58 to hold the diaphragm firmly down into engagement with its valve-seat.
Fitting loosely inside of the operating screw 57 is a stem 5.10, which is provided
with a head or nut at its upper end, and a reduced section at its lower end, which
passes through the diaphragms, and is threaded into a nut 56 on the under side
thereof.
This form of ammonia shut-off valve provides a very simple and efficient con-
struction for shutting off the flow of ammonia at various points in its circulating
system, and while Fig. 11 illustrates simply that form of shut-off valve which is
employed for instance at the end of the blow-off or filling pipe 28, shown in
Figs. 1 and 2, it is to be understood that the other ammonia shut-off valves r,
illustrated at various points in the refrigerating apparatus, are of similar con-
struction, the shape of the valve-casing being simply modified to suit the different
locations in which said valves are employed.
The means which may be employed for automatically controlling the circula-
tion of water in the cooling tank 25 are most clearly illustrated in Fig. 12.
As shown in this figure, the diaphragm chamber 23 is formed by means of a
bracket or casting 96 having a cover-plate 97 bolted thereto.
A flexible diaphragm 98 is mounted in the diaphragm chamber so as to be
actuated by the pressure from pipe 22.
Engaging the under side of the flexible diaphragm 98 is a plunger 99, engaging
one end of a lever 100, pivotally mounted in a bracket or support 101.
Near its opposite end, the lever 100 is connected to a valve-stem 105, which
extends down into a valve casing 102, and is provided at its lower end with a
needle section or valve for controlling the flow of water through a water inlet
pipe 103.
From the valve-casing 102, a pipe 104 leads to the cooling chamber 25.
Mounted on the outer end of the pivoted lever 100 is a rod 106, carrying a
coiled spring 107, which engages a threaded bushing 108, which bushing may be
secured in its adjusted position in a socket in the bracket 96 by means of a
check-nut 109.
In the normal operation of this construction, the tension of the spring 107 is
adjusted so that when the pressure in the worm or coil inside the cooling
chamber 25 rises above the desired point, the water-valve 102 will be opened, and
a supply of water will be admitted to the cooling chamber 25.
In certain cases, it might happen that the supply of water to the controlling
valve 102 might be shut off, or might, for some reason fail, and, if the pump 17
should be continued in operation, a dangerous pressure might perhaps be generated
in the coil inside of the cooling chamber 25.
In order to prevent an accident of this kind from happening, a safety cut-out
device for automatically stopping the electric motor 19 when the water supply
fails is provided.
As illustrated in Figs. 12 and 13, the rod 106 is provided at its lower end
with a spring 110, the pressure of which may be adjusted by means of washers 111
and a nut 112.
.
In the normal operation of this construction, the spring 110 will be raised into
engagement with a stop-piece 122, when the water valve 102 is opened.
Whenever an abnormally heavy pressure is generated in the pipe 22, the
pivoted lever 100 will be raised against the resistance of the spring 110.
A wire 113 is pivotally secured to the outer end of the lever 100, and extends
down through a pivoted yoke 114, and is provided with an abutment at its lower
end.

page_text: When the lever 100 is raised to an abnormally high position, the pivoted
yoke 114 will be operated to pull down upon an upwardly extending wire 115.
The wire 115 is connected at its upper end to operate an automatic cut-out,
the preferred form of which is most clearly illustrated in Fig. 13.
As shown in this figure, binding posts 117 are introduced into the circuit à of
the street, and are normally connected by a pivoted connecting-piece 118.
The connecting-piece 118 is normally held up by means of a bell-crank stop
lever 119.
The wire 115 is connected to the bell-crank lever 119 so that when said wire 115
is pulled down, the stop-lever 119 will be moved away from the contact-piece 118,
so that the electrical connections between the binding posts 117 will be broken,
and the current will be automatically cut off from the motor 19 which drives
the pump.
In a refrigerating plant which employs an electric motor for driving the pump,
it is extremely desirable to provide for automatically controlling the motor, so
that the pump will be run or worked to cause a circulation of the refrigerating
medium only at such times as is necessary, and will be automatically cut-out, or
its action stopped when the desired temperature has been reached in the space
being refrigerated.
.
To accomplish this purpose, a refrigerating apparatus constructed according to
this invention, may be provided with thermo-electric regulator illustrated in
sheets 3 and 4.
As illustrated in Figs. 4 to inclusive, the automatic regulator which is pre-
ferably employed comprises a casing 201 having binding posts 211 for the line-
wires, and three binding posts 221, the centre one of which is connected to a
thermostat 231, which thermostat 231 may consist of a bar of compound material
arranged in the ordinary manner.
The outside binding posts 221 are connected to adjustable contact-pieces, which
co-operate with the thermostatic bar 231, and also to the electrical connections
which control the contact-arm of the rheostat, as hereinafter explained.
A switch as S may be arranged on top of the casing 24, so as to pass a current
through the stopping or starting connections of the rheostat, when it is desired
to dispense, with an automatic control by the thermostatic bar 281.
The front of the casing 201 is closed by a plate of slate or similar material 241
carrying binding posts 251 and sector-shaped contact plates near the centre,
thereof, as hereinafter explained.
In order to provide for an automatic action, the contact arm of the rheostat
is preferably turned or rotated by means of a train of clock-work, as shown most
clearly in Figs. 6 and 9.
As illustrated therein, this train of clock-work comprises an ordinary clock-
spring 301, which, through a gear and pinion, drives the main shaft 311.
A second shaft 321 is driven from the main shaft 311 by means of a gear and
pinion, and a third shaft carrying a regulating plate or fan 331 is driven by a
gear and pinion from the second shaft 321:
Loosely splined on to the outer end of the main shaft 11 is a block of insulat-
ing material as 341, which carries the spring contact arm 291, which contact
arm 291 is retained in place by the bridge-piece 75, and has terminals or end
pieces co-operating with the sector-shaped contact strips before referred to.
As illustrated most clearly in Fig. 5, the sector-shaped contact strips are
arranged in two concentric rows, the outer row comprising contact strips 451, 150.
461, 471, 470, 481 and 480. The inner row comprises contact strips 601, 611
and 631.
As shown diagramatically in Fig. 5, the contact strips 451 and 611 are insulated
or without electrical connection with the motor, so that, when the spring contact
arm 291 is in the position illustrated by dotted lines in this figure, the current
will be shut off both from the field and armature of the motor A.
When the spring contact arm 291 is turned to the right, it will be seen that
:

page_text: an electrical connection will be made with the line wire through the bridge
piece 75 and the spring-contact arm 291 so as to direct the armature current
through the resistance coils 491 and 501, while, at the same time, an electrical
connection will be made through the bridge piece 75, the spring contact arm 291
and contact strip 601 to close the circuit through the field magnets of the motor.
As the contact arm 291 continues to revolve, it will be brought successively into
engagement with the contact strips 281 and 471, thus first cutting out the resist-
ance coil 501, and the resistance coil 491, so that, when in engagement with the
contact strip 471, the full strength of the current will be directed through the
armature to drive the motor at full speed.
The contact arm of the rheostat will be maintained in this position as long as
it is desired to run the motor, and, when the motor is to be cut out, the contact
arm will be started up again to turn in the same direction.
The contact strips 461 and 470, and the contact strips 450 and 480 are connected
together so that the resistance coil 491 will be first introduced into the armature
circuit, then the armature circuit will be directed through both coils 491 and 501,
and the circuit through the armature of the motor will be broken when the con-
tact arm passes into engagement with the contact section 451.
The sector-shaped contact section (31 in the inner line of contact pieces is
arranged to introduce a resistance as 511 into the field circuit of the motor just
before the motor is shut off, as it has been found that by this arrangement all
sparking may be substantially prevented.
Any desired construction may be employed for stopping and starting the clock-
work so as to turn the spring contact arm 291, as, for example, the stopping and
starting pawls hereinafter described may be directly actuated by the expansive
force of a thermostat: but, in practice it is preferred to control the starting and
stopping pawls by suitable magnets.
As illustrated most clearly in Figs. 6 to 8, notch disks 351 and 361 are secured
on the main shaft of the clock work, and co-operating with the notched disk 351
is a stopping pawl 391 for normally stopping the clock-work to shut off the
current of the electric motor, and to maintain the parts of the rheostat in the
position illustrated in Fig. 5.
Co-operating with the notched disk 301 is a starting pawl 401 which when
brought into action, will allow the rheostat arm to turn until the full strength
of the current is turned on to the motor.
The stopping pawl 391 and starting pawl 401, as illustrated, are controlled by
pins 431 and 441 respectively on a pivoted armature lever 421.
The armature lever 421 is controlled by magnets as 101 and 111.
A shunt from the street current may be sent through the magnet 101 when
the circuit is closed by the thermostatic bar moving to the left, as shown in
Fig. 3. and, when this takes place, the pawl 401 will be lifted from its notched
disk 361, and the rheostat arm will be turned so that the parts will assume the
position illustrated in the drawings.
In practice, the clock-work itself is employed to form part of the circuit
through the magnet 101, the connections of the magnets 101 and 111 with the
clock-work being preferably made by insulated spring contact arms 381 and 591
(see Figure 7) which bear upon the notched disks 351 and 361, so that, when the
parts are in the normal position illustrated in the drawings, the shunt circuit
through the stopping magnet 101 will be broken, as illustrated in Fig. 7.
The thermostatic rod 231 is located in or directly adjacent to the space being
refrigerated, and, when the temperature rises from the desired limit, the ther-
mostatic rod will complete a shunt circuit through the magnet 111, so that the
pivoted armature or lever 421 will be shifted from the position shown in the
drawings, the stopping pawl 391 will be thrown out by the pin 431, and the
starting pawl 401 will be released to engage the notch in the stopping disk, thus
lowering the tail-piece of the stopping pawl into the path of the plate or fan 331,
when the rheostat arm has been turned by the clock-work to direct the current

page_text: through the motor, while, at the same time, the circuit through the spring contact-
arm 591 and notched disk 361 will be broken.
The starting and stopping pawls 391 and 401 are preferably provided with
foot-pieces for engaging the fan or plate 331 in this manner, although, if pre-
ferred, the notches in the disk may, if desired, be made of such a shape as to act
as ratchet teeth to control the clock-work.
By employing a spring rheostat arm 291, which is confined in place beneath
the bridge piece 75, it will be noted that the rheostat arm will exert a spring
pressure both on its contact sections or feet and on the bridge-piece, and, by
means of this construction, nearly perfect electrical connections will be made
between the bridge-piece 75 and rheostat arm 291, and between the rheostat
arm 291 and the sector-shaped contact pieces which co-operate therewith.
If the street or line current should be cut off or interrupted for any reason
while the motor is running, and then be turned on again suddenly, the armature
of the motor would be liable to burn out or to be injured, and a further object of
this invention is to provide a stationary cut-out device, which will automatically
shift the rheostat to a stopping position whenever the current is broken.
As illustrated, a third notched disk 371 is secured on the main shaft 311, and,
co-operating with the notched disk 371 is a supplemental pawl 411.
The supplemental pawl 411 is arranged to engage an arm or pin projecting
from the starting pawl 401.
The supplemental pawl 411 is normally held up out of the way by a magnet 121,
which is included in the circuit from the street wires, so that, as long as the
current is turned on, and the motor is being driven, the supplemental pawl will
not interfere with the action of the stopping and starting pawls.
When, however, the street current is shut off, the magnet 121 will no longer
be energized, and the supplemental pawl 411 will be allowed to drop, and will
engage the pin or projection carried by the starting pawl 401, so that the starting
pawl 401 will be lifted, and the clock-work released to turn the rheostat arm
into stopping position.
The operation of the various devices employed in an automatic refrigerating
system, constructed according to this invention, have been so fully explained in
describing the specific construction thereof, that it is not thought necessary to
describe the operation of the entire system as a whole.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The system of automatic refrigeration, substantially as herein described,
and illustrated in the accompanying drawings.
2. The combination with the expansion valve of an automatic refrigerating
system, and means for actuating the same, comprising a lever having an adjustable
fulcrum, and two diaphragms controlling the lever, one diaphragm being acted
upon by the pressure of a confined body of expansible medium, and the other
diaphragm being acted upon by the pressure of the refrigerating medium,
substantially as described.
3. The automatic valve illustrated on the seventh sheets of drawings, which is
arranged to be controlled by a diaphragm acted upon on one side by the pressure
of a body of confined expansible medium, and on the other side by the pressure
of the refrigerating medium, substantially as described.
4. An automatic refrigerating apparatus comprising a circulating system for
the refrigerating medium, a pump, an electric motor therefor, and a combined
theremostat and rheostat for controlling the motor to maintain a substantially
constant temperature in the space being refrigerated, substantially as described.
5. The combined thermostat and rheostat for controlling the motor of a
refrigerating apparatus, comprising a rotary contact-arm, clock-work for turning

page_text: said contact-arm in one direction, pawls for stopping the clock-work in different
relative positions, and a thermostat connected to control said pawls, substantially
as described.
6. An ammonia shut-off valve for use in refrigerating apparatus substantially
as shown in Fig. 11.
7. Means for automatically controlling the supply of water employed in cooling
the refrigerating medium while the same is being condensed to a liquid, sub-
stantially as described.
8. The connections for automatically stopping the pump of a refrigerating
apparatus when an excessive pressure is generated thereby, substantially as
described.
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1
1
J
1000
FELL & JAMES,
Agents for the Applicant.