US3139501A - Control apparatus for ice making machines - Google Patents

Description

June 30, 1964 R. E. cooK CONTROL APPARATUS FOR ICE!v MAKING MACHINES Filed Jan. 22

INVENTOR. RUSSELL E. COOK ATTORNEY MHWMMHMHHWMHAVH@ United States Patent() CONTRGL APPARATUS FOR ICE MAKING MACHINES Russell E. Cook, Chicago, Ill., assignor to yRanco ilorporated, Columbus, Ohio, a corporation of Filed Jan. 22, 1962, Ser. No. 167,711

v 1 Claim. (Cl. 20h- 140) This invention relates to an improved control apparatus or system for regulatingthe operation of particulate ice making machines in accordance with the level of ice in a storage bin thereof.

It is aprincipal object of this invention to provide an improved control apparatus or system for controlling ice making machines of the above mentioned character in such a manner that the machines will be caused to operate only upon the removal of a substantial quantity of ice from the storage bin thereof, thereby Vavoiding frequent operations or short cycling of the machines upon the removal or melting of small quantities of the stored 1ce. Y

It is another object of this invention to provide an apparatus and system for controlling an icev making machine of the character mentioned comprising twotemperature sensing elements, one located at the minimum desired ice level and the other at the upper desired ice level and actuating a control device, such as an electric switch, to start operation of the machine when the ice level falls below the minimum desired level and to terminate operation of the machine only when the temperatures at both levels indicate the presence of ice. The installation of the sensing elements is relatively simple, and

the control system provides accurate and reliable operation at a minimum of cost.

In carrying out the invention the control apparatus comprises a switching means actuated by the coaction of two thermally responsive means each including a sensing element, one of which is located at a minimum desired ice level in the bin and the second located at the upper desired ice level, respectively, and which thermally responsive means are effective to actuate the switch to initiate operation of the machine when the temperature of the first sensing element increases to a degree appreciably above 32 F., and to terminate operation of the machine only when the temperatures of both sensing elements are reduced to approximately 32 F. By this arrangement, when the desired level of ice is in the bin the temperatures of both elements are held at about 32 F. by Contact or proximity to the ice and the machine is inoperative. As ice is removed from the bin and the element at the upper ice level is exposed, the temperature thereof will rise but, so long as the element at the lower level is covered by ice, its temperature is at approximately 32 F. and the machine remains idle. When ice has been removed below the lower level, the temperature of the sensing element at this level increases, thereby actuating the switching means to initiate an ice making cycle. As ice is fed to the bin the temperature of the element at the lower level decreases to about 32 F. but since the temperature of the upper element remains well above 32 F. until the level of the ice reaches this element, the ice manufacturing cycle is not terminated until the ice level in the bin is such as to reduce the temperature of the upper element to about 32 F.

@ther objects and advantages of the present invention will become apparent from the following detailed description of a preferred form thereof, the description being read in conjunction with the accompanying sheet of drawings forming a part of this specification and in which the single View is a schematic illustration of an ice making ICC In the drawing, there is shown an ice making machine 10 for manufacturing particulate ice, and comprising a chute 11 connected to an ice bin 12 in which the particulate ice 13 may be accumulated and stored for future use. Ice machine 10 may be of any type, m-any of which are well known in the art and which may be electrically controlled and, in this instance, is shown as comprising an electrically operated motor compressor unit 14 and a condenser 15 which are connected by suitable tubing to an evaporator housed within the machine 10 to form a conventional compressor-condenser-expander circuit.

When motor compressor unit 14 is energized, ice machine 10 manufactures ice in particulate form, discharging it through chute 11 and into bin 12. The operation of ice machineV 1i) is initiated and terminated in accordance with the quanitity of ice stored in bin 12 by a control apparatus generally indicated at 20, the construction and operation of which is described more fully hereinafter, and which serves to start operation of the ice machine 10 whenever the quantity of ice 13 in bin 12 falls below the level indicated in dot and dash lines at 21, and stops the operation of the ice machine whenever the ice accumulation rises above a second level indicated at 22 in dotted lines. The spread between the cutting-in level 21 and the cutting-out level 22 of the ice machine operation prevents short cycling thereof as a result of melting or removal of small quantities of ice from bin 12.

The control apparatus 20 comprises a suitable housing or frame 25 in which is mounted a snap acting switch mechanism 26 for controlling energization of motor cornpressor unit 14, which is connected between power lines L1 and L2 through switch 26 so as to be energized by suitable current, such as 110 v. A.C.,`upon closing of the contacts of the switch. Many forms of suitable switching mechanisms are available commercially and the details of switch 26 are therefore not shown. Switch 26 hasv an actuating member 27 which moves inwardly and outwardly of the switch mechanism housing to cause closing and opening, respectively, of the contacts thereof. As' is usual in snap switch mechanisms there is an appreciable difference in the positions of actuator 27 at which the contacts thereof are opened and closed. In other words, the actuator 27 is movable inwardly from a `switch open ing position, through intermediate positions in which the switch remains open, to a switch closing position. Thereafter, the actuator 27 is movable outwardly from the switch closing position, through the same intermediate positions in which the switch was open but now remains closed, to the switch opening position. Thus, when the actuator 27 is in the intermediate positions, the switch may be in either open or closed condition depending upon which of the actuating positions it last occupied. Also temperatures of two thermally responsive power means,

ent invention.

described more fully hereinafter; one of which is connected with the arm 30 through a lever 33, having arms 33a and 3311, and which is pivoted at the end of arm 33a to pivot pin 31. Lever 33 has a knife edge 33C in engagement with a post 35a of an expansible diaphragm or bellows 35 of one thermally responsive power means, which bellows is mounted to an end wall 25a of frame 25. Lever 33 is urged in a counterclockwise direction against bellows post 35a by a tension load spring 37 connected between the end of lever arm 33b and an adjustc A ing screw 3S extending through frame wall 25d and engaged in a nut 39 secured in the end convolutions of spring 37.' n

Bellows 5 5 communicates through a capillary tube 40 with the interior of a temperature sensing element in the form of a bulb 41 conveniently mounted within bin 12 on a suitable bracket, not shown, so asto be contacted by ice when the ice is above thelevel 21. This element can be positioned in the bin so as not to be disturbed by the removal of ice from the bin. Bellows 35, capillary 40 and bulb 41 which comprise athermally responsive power means, contain a suitable vapor, the pressure of whichincreases and decreases with lncreasesV and decreases in temperature so as to effect correspondingexpansion and contraction of bellows 35. `The'iluid content is so chosen that when bulb `41 experiences a temperature'increase to a predetermined temperature, for example 35 F. bellows 35 will expand and rotatevrlever 33 sufliciently Vto cause arm 33h to move arm 3i) and actuator 27 tol close switch 26 and initiate operation of the ice making machine 10. The bulb is subjected to lower temperatures than the bellows or tube so that the be rotated in a counterclockwise direction by the diaphragm or bellows 44 which is secured to the frame end -wall 25C and hasa bellows post 44a engaging a projection 45C on lever arm 45a. Bellows 44 communicatesv through a capillary tube 51 with the interior of a temtion thereof rises to the upper level indicated by dotted line 22. Bellows 44, capillary 51 and bulb 52 contain a suitable fluid the pressure of which changes uponV increases and decreases in temperature, and which duid is so chosen that at temperatures above 32 F., and within the range of temperatures normally prevailing above the ice level in the bin, such as 35 F. for example, bellows 44 holds arm 45 to an adjustable stop screw 54 supported on frame 25 and engaging the end of arm' 25a. When in this position, a projection 56 on the end of arm 4511 isk engageable by arm Stlto hold switch actuator 27 in a' position intermediate the switch operating positions of the actuator.

Assuming binv 12 to be empty, and upon the machine being initially connected to a source of power, bulb 41 n vwill be above 35 F. and the iuid pressure therein will have caused bellows 35 to move switch actuator 27 inwardly to close switch 26 through levers 33 and 30, as shown. The ice machine will then operate to manuv j. actuator 27 to a position which is short of thatjrequired Y n Aperature sensing element or bulb 52 disposed in bin 12 and adapted `to be contacted by ice when the accumulafacture and discharge ice into the bin. As the ice ac- A cumulating in bin 12'rises above level 21 and cools bulb 41 to about 32 F., bellows 35 will contract and allow lever 33 to be rotated in a counterclockwise direction under the inuence of spring 37, permitting switch actuator 27 to move outwardly until arintlengages projection 56 of lever 45 which is held-in its illustrated position because the` temperature at bulb 52 remains above about 32 F. so long as the upper ice level is below line 22.

When the arm 30 engages projection 56, actuator 27 is held in an intermediate position even though lever 33 continues to move in a counter-clockwise direction, and because the last occupied actuating position of actuator 27 effected closing of the switch contacts, the switch will remain closed as the ice level rises above bulb 41 toward bulb 52. The production of ice therefore continues until lever 30 to permit actuator 27l to move outwardly to the switch Contact opening position whereupon the production of ice by the machine is terminated.

Thereafter upon the removal or. melting of ice in bin n 12 so as to bring the level thereof below line 22 but aboveV line 21, bulb 52 being out of contact with ice will be warmed above 32 F. and bellows 44will expand and move lever 45 to stop screw 54 and depress arm 30 and to close switch .26 and initiate the production of ice. The melting or removal of additional ice from bin 12, suflicient to reduce the level thereof below level 21, will again cause bulb 41 to be warmed above 32 F. and eX- pand bellows 35 which, through levers 33 andr3tl, further depresses actuator 27 to its switch closing position to reestablish ice production by machine 10.

Y The tension of spring 37 may be varied by means of screw 38 to adjust the load on bellows 35 and hence the temperature at bulb 4t) which will effect cuttingV in of the ice making apparatus, screwk38 thereby providing a control of the sensitivity of thermal sensing bulb 41 to .the presence of ice at'level 21. Similarly yscrew 48 may be adjusted to vary the load on bellows 44 and hence determine the sensitivity of sensing bulbv 52 to the presence of ice at level 22.

male'ng machines which is responsive to the reduction of j the quantity of ice in a storage bin to a first or lower level to initiate the production of ice, and which is re-v sponsive to the accumulation of ice to a second or higher predetermined level in the bin to terminate the production of ice. It will also be recognized that the control apparatus of this invention serves to prevent short cyclingv and inefficient operation of ice making machines incorporating the control, and that the level sensing elements having no moving parts, are readily installed atthe most convenient positions in the bin, and will give long troublefree operation. l y

Although the present invention has been described in considerable detail and with specic reference to a preferred apparatus embodying the invention, it is under` stood that Vthe invention is ynot limited thereto, but rather the invention includes all those modifications, adaptations, and uses as are reasonably embraced by the scope of the claim hereof. Y Having thus described my invention, I claim: `V

Control apparatus for an electrically operated ice making machine having a bin for receiving and storing par,

ticulate ice, said control (a) a frame,

(b) switch means mounted on said frame and having actuator means movable through an intermediate apparatus comprising:

position between switch opening and switch closing positions, said actuator means being biased toward sald switch opening position, l

(c) r'st and second thermally responsive expansibleV power means each having a part movable between two positions 1n response to presence and absence of lce, said first power means beingV responsive to temperature changes corresponding to presence and v absence of ice at a lower level, said second power means being responsive to temperature changes corresponding to presence and absence of Vice at anY said rst lever means to a position for permitting said actuator means to move to said switch opening position,

(e) a second lever means pivoted on said frame and' biased by second spring means `into following engagement with said movable part of said second power means, said second power means being op-v presence of ice at an upper level to allow said second spring means to move said second lever to a` position permitting said actuator means to return to said switch opening position, and

(g) stop means on said frame engageable by said secondlever in said blocking position to prevent said second lever from moving said actuator means to said switch closing position in response to absence of ice at an upper level.

References Cited in the ile of this patent UNITED STATES PATENTS erative in response to absence of ice at an upper sos Raney f Sept 31940 level to move said second lever means to a blocking 15 ZZgggg rooms Doct'z position for, preventing movement of said actuator 2866322 Maley Dec' 30" 1958 means from said intermediate position to said switch u y ec opening position, 2,891,385 Nelson June 23, 1959 Swart June 20, 1961 (f) said second power means being responsive tothe 2988896

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