US981840A - Automatic controlling mechanism for refrigerating systems. - Google Patents

Description

E. CARPENTER & P. M. KIMBALL. AUTOMATIC CONTROLLING MECHANISM FOR REFRIGERATING SYSTEMS.

APPLICATION TIL ED MAR-.15. 1007.

2 SHEETSSHEET I Patented J an. 17, 1911.

wa- 1M0 me o I E. CARPENTER & F. M. KIMBALL. AUTOMATIC GONTROLLING MECHANISM FOR REFRIGERATING SYSTEMS.

APPLICATION FILED MAR. 15, 1907. 981 ,840. Patented Jan. 17,1911.

2 SHEETS-SHEET 2.

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, ZL W (9M 9 4. WI. JQQ/M UNITED STATES PATENT OFFICE.

EUGENE CARPENTER, NEWTON, AND FRED 'KIMBALL, OF SOMERVILLE, MASSA- CHUSETTS, ASSIGNORS TO THE AUTOMATIC REFBIGERATING COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

AUTOMATIC CONTROLLING MECHANISM FOR REFRIGERATING SYSTEMS.

T 0 all whom it may concern:

Be it known that we, EUGENE CARPENTER.

paratus involves a conduit for the rctrigerant, whose low pressure side is located in the space to be refrigerated, whether the same be a cold storage chamber for example, or the cooling tank of a brine circulating sys tem; a pump' for compressing and circulating the refrigerant in said conduit,'a motor (usually electric) t'or operating said pump, and 'a thermostat or other equivalent device in the refrigerating chamber or space to control the stopping and starting of the motor and therefore of the refrigerant circulating pump, in accordance with ten'iperature con dit-ions in said chamber or space. In such systems, situated as they are in a great variety of widely detached locations, the water supply depended upon for the condenser upon the high pressure side of the refrigerant circuit is not uniforn'ily reliable or constant, and should its flow be diminished or cut oil, or should for any reason a properly reduced temperature be unobtainable on the high pressure side of the retrige ant circuit, an abnormal pressure may develop in the latter, interrupting the proper normal operation oi the apparatus, or even resulting in the accumulation of dangerous pressure.

The object oi our invention is to prevent absolutely the operation of the pump, and to throw it out of operation it it is in opera- .tion, automatically, should abnormal presill sures develop the refrigerant circuit, or should the condenser water supply fall to an inmlequate amount. and our invention particularly ontemplates the coaction of ooth the rctri nt pressure and condenser fluid pressure ud any other fluid pressure whose abnormality might be prejudicial to the Specification of Letters Patent.

Application filed March 15, 1907.

f said switches b of circuit, and the pump absolutely pre- Patented Jan. 17, 1911. Serial No. 362,518. A

proper operation of the system) in controlling the motor-so that they have to be in substantially normal state inorder that the motor shall start or continue in operation and the development of abnormal pressure in either (or any) conduit will automatically stop the motor.

In the forms of our invention here illustrated and more particularly described, the driving power for the pump is supposed to be an electric motor, but the invention is not to be understood as so limited, for the controlling devices here shown are applicable to other forms of motive power, and the member controlled thereby and itself c0n-- trolling the motor, may be a switch as here shown, or the controlling lever or other device of a water, steam or gas motor.

In the accompanying drawing Figure l exhibits partly in diagram and partly in sectional elevation, so much of the apparatus only as is necessary to an understanding of our invention in a form employing two separate switches arranged in series in the motor circuit. Figs. 2 and 3 show respectively in side and plan views, a form of our invention wherein a plurality of controlling devices control one switch. The above figures show two forms of the invention, in which the circuit is closed manually and automatically controlled only as to the opening oi the circuit. Fig. at shows in diagram a further and preferred development of the system in which both the opening and the closing of the circuit are controlled by the fluid pressure devices.

Referring to Fig. 1; 1, 2, are members controlling the stopping and starting of the refrigerant circulating pump. As here shown, they are hand knife-blade switches pivoted at 3, as, either one alongside of the.

other on the same base plate, or on separate base plates 5, 6, as here shown. They are so hung and weighted or spring actuated by leaf spring a as to be held normally away from their contacts, but may be shifted by hand to engage-a series of contacts 7, S, 9, l0, arranges in series in circuit 11, which mayiuclude i pump motor or the controlling circuit thereof. Should either of open, the motor cut out vented from operation. Only two switches are here shown, but it will be apparent, that phragm an additional one may be supplied for each part of the refrigerating system, an abnormal or changed condition in which may render necessary or desirable the stopping of the motor and the consequent stoppage 0 circulation of the refrigerant. One of. said switches may for example be controlled by the pressure in the condenser-water conduit, the other by the ressure in the high pressure side of the re rigerant conduit. A third might be controlled by the low pressure side of the latter. Various means may be adopted to this end, and those herein shown are intended to be illustrative merely, and may be modified to suit the requirements. As here shown, each switch arm 1, 2, is actuated by spring a, and has a shoulder 12, 13, engaged by the short arm or pawl 14, 15 of an angle lever pivoted to the base plate and connected at the end of its long arm 16, 17 to the pin 18,19 of the diaphragm or piston 20, 21 in a pressure chamber 22, 23. The angle levers-are so actuated by springs 14 or other equivalent means, as to prevent the short arms thereof engaging with the shoulders of the switch levers except at such times as the diaphragms are in position due to normal operation of the system. The pressure chambers may be in various forms, for example, a cylinder and piston, a Bourdon tube, or equivalent construction may be used; but as the simplest form, we have shown and prefer the inclosed ressure chamber here illustrated, with fiexi le diaphragm directly controlling the. pin18, 19.

The pressure chamber 22 is, on the side of the diaphragm opposite from the controlling pin 18, .connected, as by pipe 24, with the condenser water conduit,while the opposite side of the pressure chamber 23 is connected as by pipe 25 with the high pressure side of the refrigerant circulating conduit. Thus one of the diaphragms' is controlled {by'the pressure of the water supply to the condenser, and the other by the refrigerant circulation, both of which have to be in roper condition 111 order that the system s al operate. Referring for example to the switch 1 and its controlling ressure chamber, it will be seen that normally the pressure in pipe 24 will hold the diaphragm 20to the position shown in full lines holding the locking awl 14 in position to engage the shoulder 0)? switch arm 1, but

llf there is an inadequate pressure of water in the pipe 24, diapxhragm20 will be drawn in to the position s own in dotted lines, the its switch and if the latter is closed it cannot remain closed; also if, with the pump in operation, pressure develops in the pipe 24, the diamovin into the position shown in dotted lines, wil disen age the pawl 14 from the switch, and the e ectric circuit will be automatically opened Referring. to switch cuit.

low

2, it will be seen that if when said switch is manipulated to close it, the pressure in the pipe 25 is abnormally high, the diaphragm 21 will be in the position shown in dotted lines, and the switch cannot be held closed andthat the pump will not be started, and if with the pump in operation such abnormal pressure develops in the refri erant circuit, the switch will be automatical y unlatched and will open the motor circuit and stop the pump. A duplicate of switch 1 and its controlling mechanism may, as already stated, be arranged in series therewith, but connected to the low pressure side of the refrigerant conduit so that abnormal drop of pressure therein would also open the cir- The circuit would in that case be controlled by all threeswitches, all of the controlling pressures of which would have to be in normal condition in order that the motor mi ht be started and kept in operation.

ither switch 1, 2, may be controlled by several pressure chambers. For example we have illustrated in Fi s. 2 and 3 how switch 1 may be controlled by pressure in two or more pressure chambers in several fluid circulating conduits. \Vith this form of the mechanism switch 2, arranged in series with switch 1 may still be employed, and be controlled by other fiuid pressure devices or it may be omitted and the motor circuit be controlledby the single switch 1 controlled by all the fluid pressure circuits whose liability to abnormal conditions -might be prejudicial to the proper operation of the system. In Figs. 2, 3, a single controlling switch or lever 1 is employed having the pivoted locking pawl lever 14, 16 engaging the shoulder 12 thereof. The spring 26 holds and returns the pawl lever to engaging osition, so that in the normal operation 0 the apparatus, the pawl 14 will engage and lock the switch whenever it is closed. The long arm 16 of the'pawl lever enters a yoke 27 fixed to the base plate. Each diaphragm pin 28, 29 of the condenser water-pressure and refrigerant-pressure controlled chambers 22,23, is prolonged to enter said yoke from opposite sides in rear of the arm 16 and they have inclines or cam faces 30 at their adjacent ends engaging the rear edge of arm 16. Thus abnormal pressure in either chamber 22, 23, causing an outward movement of the corresponding pin 28, 29 will cause movement of lever 16, 14 suiticient to free the switch and; allow it to fall and open the circuit. It will be apparent that with this form also, both or all controlling pressure conditions must be normal to allow the switch to remain closed.

The pressure controlling devices above described may be made adjustable to suit the varyin conditions, and may be provided with signa ing apparatus to indicate return We have the apparatus shown in Fig. 3.

Suitable devices, as for example, springs of any desired form and adjustable if desired in either or both directions by adqusting screws as shown, may be employed to adi'ust the pressure required for releasing v or ho ding the switches.

' The arrangement is evide tly capable of ex- .tension, by simple addition of pressure chambers, &c., to the controlling of theswitch by any number of members. In this way, a pressure chamber controlled by the low side of the refrigerant circuit may be added. However many such controlling devices are used, all must indicate a normal condition in their several conduits before the motor can be started and any departure from normal con ditions, of a predetermined amount, in any conduit, will stop the motor The pins 28, 29 may be"made' with adjusting'means such as turnbuckles 33, placed on pins 28;, 29 so that their length mav be adj uste'd as required for different con itionsdifferent normal positions for example of the respective diaphra ms.

A signal circuit as or example the light circuit 34, may be so arranged as to give a signal when both or all of the controlling pressure conditions are normal. As here shown the signal-circuit has terminals 35, 36, engaged by contacts 011 pins 28, 29 when the diaphragms are in normal position, so completing the circuit through the engaging metal parts 27, 28, 29. I

In .Fig. 4 we have illustrated a further development of the system whereby two or more pressure controlled devices coact .in controlling both the starting and the'stopping of the motor, as for example by closing and opening of the motor circuit, and we show associated with the motor controlling circuit, signal circuits for giving warning of the operative or inoperative condition of the main circuits;-in both main and signal circuits, the contacts being so arranged that the abnormal condition of any controlling mechanism will stop the motor and give the appropriate signal, while the restoring of all controlling mechanisms to normal w1ll start the motor and give another and appropriate signal.

Two pressure controlled devices are shown by way of example at 22, 23', their diaphragm-operated pins 18, 19 hearing con tact or brldge pieces 37, under normal conditions of pressure in chambers 22, 23, bridging the space between brushes 38, 38 and 39, 39 respectively but adapted, by the development of abnormal conditions in one or both of the pressure chambers to be.

shifted-one or both--to bridge the space between the brushes 40, 40 or 41 41-01 both.

here shown applied to a system in which the motor circuit is opened and closed by-a sole noid arranged in acontrolling circuit. For simplicity of drawing, the rheostats of both the main and controlling switches are omitted. The main or motor circuit is shown at 42, the motor at 43, the controllingswitch thereof at 44 and its controllingsolenoid at 45 arranged in series with a resistance 46 in a branch circuit 47 from the motor the combined resistance of the solenoid and resistance coil-beingsuificient to prevent the raising of switch 44.

The contacts 40, 41, are in parallel in a circuit 48 around the solenoid, and in parallel .with them across 'the ci:rcuit 48 is a switch'50 which may be hand operated or thermostatically controlled-as by a thermostat placed in a refrigerating chamberand which when placed on contact 51 short-circuits solenoid 45 and opens or keeps open the motor circuit at 44. In the same manner, therlevelopment of abnormal iconditions in either pressure chamber 22, 23 shifting the corresponding bridge 37 between contacts 40 or 41, will short-circuit the solenoid and open or keep open the motor circuit; The other contact 52 of switch 50 is in a branch circuit 53 around resistance 46 in which the contacts 38, 39 are arranged in series. When the condition in both pressure chambers is normal, and the branch circuit 53 is therefore closed by bridge pieces 37 at both-38 and 39, and the switch 50 is brought, by hand, thermostatically or otherwise, upon contact 52, the, resistance 46 is short-cir- .cuited, the lifting power of solenoid 45 is augmented, the switch 44 closed and the motor 43 started. If now the circuit 53 be opened at any int, as by shifting of switch 50 away rom contact 52 or by the moving of a bridge-piece 37 from contact with brushes 38 or 39 under a change of pressure in either chamber, the motor circuit may still be maintained at 44 by even the slight current passing through both solenoid and resistance, but ifthe n the solenoid be short circuited bythe switch 50 being brought in contact with contact 51 or by either, bridge-piece 37 being brought in contactwith brushes 40 or 41, will be immediately opened at 44 and the motor stopped.

It will, be seen that by adopting a series arrangement for the contacts in branch cir' cuit 53 all of the controlling devices have to be in normal condition in order to en able the motor to be started and that by adopting a parallel arrangement for the contacts in branch circuit 48, the development of abnormal-or sufliciently abnormarl-condition in any controllingmechanism will ositively open the motor circuit and stop t e motor if it is'in operation, or will prevent its being started if 1t is not.

circuit' the motor circuit the other It is also apparent that the system could-be expanded to include any additional. number of controlling devices and that with the arrangement of circuits indicated, both resistance and solenoid cannot be cut out at once-one or the other is always in circuit and thus dead short circuits are prevented. As each member 37. returns to normal position it not only opens the contacts at 40, 41 thus opening the solenoid short circuits 48 and preventing the thermostatic or other switch 50 from short circuiting the solenoid, but it completes at 38, 39 the short circuit to contact 52 around resistance 46, so that when the last member 37 returns to normal, it is only necessary for switch 50 to move to contact 52 in order to short circuit resistance 46, energize solenoid 45 and start the motor and resume the work of refrigeration.

The arrangement of circuits adapted for the motor controlling circuit-motor-ciremt opening devices in parallel and motor-circuit closing devices in series-is followed also in the signaling circuits which Wlll now be described. The circuit 54 of local battery 5'5 is controlled by a switch 56, closed automatically when the motor circuit 15 opened, as for example, bythmshiftrng of switch 50 to point 51. Two branch circuits 57, 58 from the battery include two signaling devices 59, 60preferably dissimilar .111 character, to render their signals readily distinguishable audibly or visually or both. In branch circuit 57, contacts 61, 62, (corresponding in number to the number of devices controlled by abnormal the system), are arranged in parallel and arranged to be closed automatically when any of such devices, moved by the occurring of such abnormal conditions, opens the motor cont-rolling circuit. To this end the pressure controlled pins 18, 19, may have non-conducting lugs or heads 63, adapted, in abnormal position of their controlling members, to close the corresponding contacts 61 or 62, and thus give Warning by the signal 59 ofthe abnormal condition. In branch circuit 58, contacts 64, are arranged in series and adapted to be closed by the lugs or heads 63 when the latter are in normal positionthus indicating by signal 60 whether all of 'the controlling devices which indicate abnormal conditions-are at normal. The signal 60 may appropriately be a lam and the signal 59 a bell. If the circuit 54 closed at 56 when the motor is stopped by any means, as for example directly by the opening of the motor switch 44, or, as shown, bythe sw tch 50 being brought against contact 51 the alarm signal circuit 57 canbe completed by closing either of the contacts 61- or 62 while the signal device 60 will be actuated only by the closing of both contacts 64, 65. Thus when abnormal conditions occur and the conditions in motor circuit is open, closing contact 56, the same abnormal conditions which have stopped the motor will close contact 61 or 62 allowing the local battery current to pass through alarm signal 59. The alarm will continue to be operated until all abnormal conditions have passed and the parts 18, 19, 63 have returned to their normal position,

allowing contacts 61 or 62'to be broken.

When all the conditions have returned to normal, provided the motor has not been started, so that contact 56 is still closed, the signal circuit will be completed through 64 and 65 and the operating of signal 60- which may as stated he a light-will indicate that conditions are pro er for the motor to be again started. The clbsing of the mo tor starting switch breaks the contact 56 making both si al circuits incomplete and both alarms an visual signalinopera'tive.

It is obvious that our system as herein described is capable of considerable variation within, the scope of the following claims. For example the motor 43 is not necessarily an electric motor. It may be an engine of any desired kind. Theswitch 44 may represent the controlling lever of asteam or hydrocarbon en ine or the switch of the sparkmg circuit 0 the latter.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is: a

1. In apparatus of the character described, the combination of a motor, a plurality of devices independently responsive to normal and abnormal conditions in the parts of the system, a motor controlling circuit having means in series controlled to close it to control the starting of the motor, by normal conditions in the several parts of the system and a motor controlling circuit having means in parallel to close it to stop the motor by abnormal conditions in any part of the system.

2. In apparatus of the character described, the combination of a motor, a starting circuit therefor, a stoppin circuit therefor, contacts ,arranged 'n series-in the starting circuit, contacts arranged in parallel in the stopping circuit, and means controlled by independent mechanisms responsive to conditions of different par-ts of the system, to close all the contacts in the startin circuit when all the conditions are norma and to closeone'of the contacts in the stopping circuit when the condition in any part of the system is abnormal. i

, 3. In apparatus of the character described the combination of means for stopping and starting a motor, a lurality of pressure controlled controlling evices for. said stopping and starting means, a signal, and means for operating said signal by the conjoint action 0 said controlling devices."

4. In apparatus of the character described,-

the combination of a plurality of devices actuated by changing conditions in different parts of the system, a signal circuit having a )lurality of contacts in series each controlled y one of said devices and a signal circuit having a plurality of contacts in parallel each controlled by one of said devices. 5. In apparatus of the character described,

I plurality of contacts in series each controlled y one of said devices, a signal circuit having a plurality of contacts in parallel each controlled by one of said devices and a motor 5 controlling switch controlling also both of said signal circuits.

EUGENE CARPENTER. FRED M. KIMBALL.v

the combination of a plurality of devices Witnesses: actuated by changing conditions indifferent E. J. MGDUFFEE, parts of the system, a signal circuit having a, i L. E. SMITH.

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