US 3850005 A
An automatic ice cube making machine of the type having a plurality of open bottom cells fixed adjacent an evaporator with a moveable closure plate operated by a motor to move the plate from an ice forming cell-closure position to an ice discharge position. The improvement residing in the control circuitry utilizing two separate thermo static switches responsive to the evaporator temperature for moving the closure plate.
Claims available in
Description (OCR text may contain errors)
United States Paten Sayles ICE CUBE MAKING MACHINE 5] Nov. 26, 1974 3,277,661 10/1966 Dwyer ..62/348X Primary Examiner william E. Wayner Attorney, Agent, or FirmAmster and Rothstein [5 7] ABSTRACT An automatic ice cube making machine of the type having a plurality of open bottom cells fixed adjacent an evaporator with a moveable closure plate operated by a motor to move the plate from an ice forming cellclosure position to an ice discharge position. The improvement residing in the control circuitry utilizing two separate thermo static switches responsive to the evaporator temperature for moving the closure plate.
15 Claims, 7 Drawing Figures PATENH HUVZBIQM 185(LOU5 SHEET F Q INVENTOR. WILLIAM E SAYLES ATTORNEYS PATENTL 3,8501b0O5 saw an? INVENTOR. WILLIAM F. SAYLES ATTORNEYS NEIL, $21M 2 3 HM WEN 3 @F a ATTORNEYS ICE CUBE MAKING MACHINE This invention relates to refrigeration equipment and, more particularly, to improved apparatus for furnishing uniformly shaped ice cubes more rapidly and more efficiently than in the past.
In recent years, the demand for refrigeration equipment of all kinds has witnessed a dramatic surge upwards. Emphasis has often been placed on the application of such equipment to the requirements of the individual consumer. Thus, with respect to the preparation of ice cubes, the domestic needs of the consumer, as well as the more commercially oriented needs of industry, have been given attention by manufacturers and designers. It is, for example, well known that ice cube making equipment is required in varying degrees in home refrigerators. Moreover, many homes even have their own separate machines to provide for their greater individual needs. Then, too, commercial ice cube making equipment is available for very high demands such as in coin-operated public apparatus, restaurant equipment, etc.
While various types of equipment are currently available to fulfill most of these requirements, such as equipment has not proven altogether satisfactory. All too frequently, the ice cube making procedures are too time-consuming. Accordingly, where rapid turnover and high demand are required, present systems are often inadequate. Furthermore, currently available equipment often fails to produce uniform ice cubes as to clarity, the desired cubical shape, frozen consistency, etc. These failings are often based on the unavailability of adequate means to control the freezing and harvesting" cycles. Thus, the prior art often uses weight-responsive control equipment to detect the moment when, based on runoff from the ice cube freezing containers, harvesting should commence. Such equipment, which is generally spring-loaded, is not sufficiently sensitive to allow for the accurate termination of the freezing cycle and thus the commencement of the harvesting cycle.
And where the prior art has recognized that thermostatically controlled instrumentation would be desirable, such equipment has only been added in a passive manner in conjunction with the spring-loaded equipment previously adverted to. Thus, in one prior art arrangement, when the water rises to a predetermined level in the storage tank, the water level in a controlling pilot tank similarly rises. When the pilot tank level is high enough to trigger a weight-responsive control, a switch is activated which then cuts in a circuit controlled by a thermostat. However, the great advantages of thermostatic control are not realized in the prior art circuitry due to the internal dependence on weightresponsive and spring-loaded equipment. Due to factors such as humidity, temperature variations, etc., it has been found that such equipment is generally unde sirable in terms of controlling ice cube making machines.
Also contributing to the time-consuming nature of ice cube making according to the prior art is the failure to retain as much as possible of the water which is introduced into the system at any time. For example, several prior art machines include a drainage cycle which serves to completely dispose of stored water during each ice cube harvesting cycle. Accordingly, each subsequent charge" of water must be correspondingly greater to compensate for this cyclical water loss.
Moreover, while the prior art systems generally do .re-
tain and recirculate the water which is introduced into the ice cube making receptacles and does not initially freeze therein, these systems make no effort to retain the cleansing water which is passed over the freezing plate in such systems. Thus, following a harvesting cycle, the plate is cleaned of any ice which may remain thereon and the prior art then disposes of this excess water. It has been found that the retention of this water and its introduction into the recirculation system, thus allowing for its subsequent freezing inthe ice cube receptacles, significantly reduces the time required for the freezing cycle.
' It is therefore an object of this invention to furnish an improved ice cube making machine to obviate one or more of the aforesaid difficulties.
It is also an object of this invention to furnish equipment'for markedly reducing the time required for the freezing cycle in an ice cube making arrangement, thereby resulting in increased ice cube production.
It is also an object of this invention to operate an ice cube making machine in a more efficient manner, thus requiring significantly reduced quantities of water to produce the same numbers of ice cubes as machines have produced heretofore.
It is still another object of this invention to produce more satisfactory ice cubes in terms of their shape, size, weight, clarity, etc.
It is a further object of this invention to provide more efficient and accurate control arrangements to govern the cycles producing ice cubes of desired shapes.
ln one particular illustrative embodiment of the principles of this invention, an ice cube making machine is formed with a hinged storage tank assembly which is capable of dropping into a lower inclined position during the ice cube harvesting" cycle, and. under the influence of motorized control, is returned to a substantially horizontal position during the ice cube making cycle. Referring to these two cycles, the ice cube making cycle is initiated when the hinged tank assembly is returned to the horizontal position. At this time, a horizontal freezing plate forms the upper surface of the assembly and acts as a bottom closure for a grid of openbottom ice cube receptacles in a mounted evaporator and freezing assembly. Coolant coils are located conveniently above the ice cube making receptacles and when the ice cube making cycle has commenced, the coolant flows through the coils under the influence of a typical compressor unit.
Also in response to the commencement of the .ice cube making cycle, water which has been stored in the reservoir at the lower portion of the tank storage assembly is introduced into a pump which is activated at this time. The pump forces this water into a recirculating chamber which communicates with a plurality of header tubes running the length of the freezing plate. The pump pressure isadjusted so that thewater which is introduced into these tubes below the freezing plate is forced upwardly from the header tubes through small orifices in the plate into respective ice cube freezing receptacles in the mounted evaporator assembly previously referred to. Due to the quite cold environment established by the coolant flowing through the freezing coils, most of the water thusly introduced into the ice cube freezing receptacles adheres to the top and sides thereof and forms the shell of an ice cube; gradually, as more water is so introduced, the entire ice cube takes shape in each of the receptacles. Any water which does not initially adhere to the top or side walls of the freezing receptacles is guided through appropriate additional recapturing orifices in the plate back to the reservoir in the storage tank. This allows the water in the reservoir to remain at a relatively cool temperature with relation to supply or main water which is generally used to charge the system (see below).
One advantageous aspect of the present ice cube making machine involves the use ofa thermostatic control to detect the precise moment when the ice cubes have properly formed in their various receptacles. Generally, as previously referred to, the prior art would measure (e.g., weigh) the quantity of runoff water from the various receptacles (i.e., water which had not initially frozen) to indicate when the freezing cycle should terminate. However, as noted above, this is a relatively insensitive measuring technique and is not nearly as desirable as the thermostatic control utilized herein. Accordingly, the thermostatic control is adjusted so that at the precise moment when the freezing environment is reduced to a temperature sufficiently low that substantially all the freezing receptacles have ice cubes frozen therein, the freezing cycle will be terminated, thus commencing the harvesting cycle.
In response to the activation ofthis thermostatic control, several devices are energized. initially, a circuit is closed for the activation of a reversible actuator motor which controls the positioning of the hinged storage tank and plate assembly. In this particular instance, the motor is activated so as to permit the assembly to assume its lower, inclined position. An appropriate selfoperated toggle switch is then activated to turn off the motor when the lower position is reached. An activating arm linked to the movement ofthe storage tank and plate assembly causes a "hot gas" solenoid in the path of the coolant to increase the cross-sectional area of the entry to the coolant coils, and the resultant unblocking causes the coolant" to act as a heating agent throughout the coils of the evaporator assembly. Accordingly, as soon as this solenoid is activated, the presence of the hot gas in the coils begins to dislodge (i.e., by slight melting) the ice cubes from their frozen positions within the ice cube receptacles. Since the plate has been lowered so that it no longer forms the bottom of the receptacles, the ice cubes can fall by gravity and slide along the inclined plate into an ice cube storage bin for collection.
The lowering of the hinged assembly also deactivates the water pump so that during the harvesting cycle, no water is introduced into the recirculating system. However, some main water must be introduced into the system in order to keep it functioning continuously. It is noted that by eliminating the wasteful drain cycles typical of the prior art, the machine of this invention operates with substantially less water per cycle. This water is generally introduced by means of a supply header which runs the width of the freezing plate and is disposed somewhat above it at the upper inclined portion thereof. A water solenoid is activated by the lowering of the hinged assembly and a predetermined charge of water is introduced through the solenoid and into the supply header, whereupon the wter is gradually and continuously deposited at the upper edge of the freezing plate. This water serves several functions. Initially, it serves to replenish the water in the reservoir of the storage tank. This is achieved by the water dipping through the recapturing orifices in the freezing plate. In addition, however, this water serves to remove any iced portions from the freezing plate to avoid plate freezeup. This cleaning effect has often been disregarded by prior art systems and the water used therefor discarded when the cleaning is completed. However, the present invention makes use of this cleaning water and retains it for use in the recirculation system. This is achieved in one illustrative embodiment of this invention by forming the reservoir of the storage tank assembly with a protruding lip or catch basin which retains this water as it flows off the plate (since the plate is in its inclined position). This water then mixes with the normally stored water in the reservoir and since it is much cooler than that introduced from the main supply, and also because no water is drained from the reservoir, significant increases in the speed of the freezing cycle are achieved. Accordingly, the time required for the freezing cycle is markedly reduced.
The thermostatic control of the freezing cycle previously referred to it also utilized to control the length of time of the harvesting cycle. For example, when the thermostatic control, having been previously appropriately adjusted, recognizes that a suitable high temperature has been reached, this is established as the completion point of the harvesting cycle. This adjustment is made so that all ice cubes will have previously been dislodged from their various receptacles and sufficient water has been added through the water solenoid to both cleanse the freezing plate and to replenish the reservoir supply. Thus, when the thermostatic control operates in response to this higher temperature, the reversible actuator motor is activated so as to return the storage and tank assembly to its substantially horizontal position, at which point the self-operated toggle switch is thrown to stabilize the assembly in this position. Once again, the horizontal freezing plate forms the bottom closure of the freezing grid receptacles. Simultaneously, the hot gas solenoid constricts the coolant passageway so that the flowing gas can assume its cooling function. In addition, the water solenoid is deactivated, thereby terminating the entry of main water into the reservoir, and the water pump is again activated to recommence recirculation. Water is once again introduced into the plurality of header tubes below the surface of the freezing plate, forced upward through the appropriate orifices into the freezing receptacles and the ice cube making or freezing cycle is again commenced.
It is therefore a feature of an embodiment of this invention that an ice cube making machine utilizes a reversible self-controlled actuator motor to position a storage tank assembly between an ice cube making position and an ice cube harvesting position.
It is a further feature of an embodiment of this invention that temperature-responsive means are utilized to control the respective durations of the ice cube making and harvesting cycles in an ice cube making machine.
Still another feature of an embodiment of this invention includes facilities for retaining water utilized as an ice-removing agent and subsequently introducing said water into a recirculating system during a freezing cycle.
The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment demonstrating objects and features of the invention, when taken in conjunction with the accompanying drawing, wherein:
FIG. 1 is an overall perspective view of an ice cube making machine in accordance with this invention, with the cover omitted to show a storage and tank assembly in an ice cube harvesting position;
FIG. 2 is an enlarged plan view of the freezing and evaporator assembly of an ice cube making machine, including the freezing coils, and portions of the water recirculating and pumping apparatus shown in phantom;
FIG. 3 is a fragmentary and enlarged front view of an ice cube making machine indicating the ice cube harvesting position;
FIG. 4 is a fragmentary and enlarged front view, partly broken away and partly in section, of the ice cube making machine in its ice cube making or freezing position;
FIG. 5 is a fragmentary sectional view of the relationship between the freezing coils, ice cube making receptacles, freezing plate and water entry header tubes in the ice cube making arrangement of the invention;
FIG. 6 is a fragmentary sectional view, taken along the lines 6-6 of FIG. 5 in the direction of the arrows; and
FIG. 7 is a schematic diagram of the wiring for the subject ice cube making machine.
A general perspective representation of the ice cube making machine of the present invention is given in FIG. I, where the cover has beem omitted in order to expose general portions of the inner mechanisms. For example, the overall machine 10 has an ice cube receiving bin 12 with several illustrative ice cubes 14 shown therein. The upper portion of the machine includes an evaporator and freezing assembly 16 having convoluted evaporator coils 18 above an upper surface 17 of a grid of ice cube freezing receptacles 19 (not shown in FIG. I, but see FIGS. 3-6). The tank means and closure plate are illustrated as the storage tank and plate assembly 20 which is shown in FIG. I in the socalled harvesting" position where ice cubes can drop from the evaporator assembly 16, onto the inclined surface of the plate 24 and thence into the ice cube bin 12. Reference to FIG. 3 will indicate the enlarged and more highly detailed version of the harvesting position. lncluded'in the rendering of FIG. 1 are a reservoir 22 at the lower portion of the assembly 20 and a catch basin or lip 26 protruding past the end of the plate 24 to catch water flowing along the upper surface of plate 24 after excess ice has been removed therefrom. With storage tank assembly 20 in its inclined position as shown in FIG. 1, linking arm 30 is also in a relatively lower position such that toggle switch 34 is switched to activate the hot gas solenoid 32 (see FIGS. 24) in a manner to be more fully described below. The assembly 20 is maintained in its lowered harvesting position by virtue of hinging at its upper end and by the connection including link 36 and spring 38 to mounting plate 40 at the other end.
The plan view of FIG. 2 shows the evaporator coils l8 asthey are disposed above the surface 17 of the evaporator assembly 16. In addition, aperture 17a are included in the upper surface 17 of the evaporator assembly in order to allow for the escape of air during the formation of ice cubes in receptacles 19 (see FIGS. 5 and 6), and to promote the ease of release of the ice cubes during the harvesting cycle. With reference to FIGS. 5 and 6, it is noted that during the freezing cycle, water is pumped into header tubes 52 and thence upwardly into the ice cube freezing receptacles 19 through header orifices 24a in the plate 24. Water then commences to adhere to the top and side walls of the receptacles 19. The water which does not so adhere drips down through recapturing orifices 24b in the plate 24 and is accumulated in the reservoir 22 in the storage and tank assembly 20. The relationship between orifices l7a, 24a and 24b can best be appreciated by reference to FIG. 2, by noting the broken away portion thereof indicating the orifices 24a and 24b.
Prior to a description of a typical operational cycle of the machine of the present invention, the functioning of various portions of the control and circulating apparatus, including the recirculation means will now be described with reference to FIGS. 2, 3 and 4. In this regard, the edge view of recirculation chamber 44 is shown in FIGS. 3 and 4, while its plan view is presented in FIG. 2. Typically, the water which is stored in reservoir 22 is circulated through conduit 46 to and under the influence of water pump 28, and out therefrom through pipe 48 to the recirculation chamber 44. During the ice cube freezing cycle (FIG. 4) the water is then forced from the recirculation chamber 44 through the plurality of oval-shaped header tubes 52 (see FIG. 6) and thence upward through inlet apertures 24a into the various freezing receptacles 19.
When the storage tank and plate'assembly 20 is in its inclined down" position shown in FIG. 3, it has been previously noted that the water solenoid 54 is activated; this serves to deliver a charge of supply water through connecting pipe 55 to a header 50. Water is then deposited from header tube 50 at the upper portion of plate 24, thereby flowing downwardly along the inclined plate and cleaning any freeze-up conditions thereon. Moreover, the water in reservoir 22 is replenished by the passage of such deposited water through the recapturing orifices 24b in the plate 24. In addition, it is noted that the position of catch basin 26 is such that any water reaching the edge of plate 24 will be recaptured within reservoir 22 by virtue of the provision of catch basin lip 26.
With respect to the supporting of storage tank and plate assembly 20, it is noted in FIGS. 3 and 4 that the entire assembly, including the water pump 28, is piv oted at pin 53 on the left-hand support or mounting plate 51; the overall'assembly 20 is rigidly affixed to pivoted bracket member 57, thereby allowing for relatively free movement of the assembly 20 under the sole control of reversible actuator motor 70. For example, referring to FIG. 3, when the assembly 20 is in its lower extended position corresponding to the harvesting cycle ofthe machine, spring 38 is extended between its link 36 and tie rod or pin 43 on the side plate of the assembly 20. The link 36, which is in turn pivoted at pin 41 on mounting plate 40, connects with arm 39 which serves to throw toggle switch 42 and thereby deactivate the actuator motor when the assembly 20 has been lowered to the position shown in FIG. 3. Similarly, when the actuator motor is energized so as to raise the assembly 20, the clockwise rotation of link 36 about pin 41 ultimately serves, upon lof such rotation, to again activate toggle switch 42 and thereby de-energize the actuator motor 70 when the assembly has been raised to its substantially horizontal position. The compressed position of link 36, spring 38 and arm 39 which then exists is shown partially in phantom in. FIG. 4.
CYCLICAL OPERATION FIGS. 3 AND 4 When the machine of the present invention is in the position indicated in FIG. 3, the ice cubes 14 shown falling off the plate 24 and towards the bin 12 has just been dislodged from their various ice cube making receptacles 19. This is the. harvesting position of the machine. While the ice cubes 14 are being so harvested, relatively hot gas is being passed through the evaporator coils 18 resulting in the dislodging of the ice cubes 14 from their receptacles 19. The passage of hot gas through the coils l8 continues until the previously adjusted thermostatic motor control 56 and cycle control 94 determine that the temperature in the vicinity of the paritions 19 is sufficiently high so that all of the ice cubes will have been harvested. Until that time arrives, a water charge is being introduced under the influence of water solenoid 54 and through pipe 55 to header 50, whereupon the water is discharged onto the plate 24 to provide for cleaning thereof and to replenish, through orifices 24b (FIG. 2), additional water to replenish that in storage reservoir 22. In accordance with the present invention, it is noted that any water which flows down the plate 24 and which does not pass to the reservoir portion 22 through the orifices 24b is nevertheless recaptured by the reservoir 22 by virtue of catch lip 26. The prior art machines generally disposed of this cleaning water, therey impairing their efficiency. As previously noted, at this time the water pump 28 is in its of condition, so that no water is being recirculated from reservoir 22 to recirculation chamber 44. Finally, actuator motor 70 has been deactivated by the action of rod 39 in switching toggle switch 42 after the assembly 20 was lowered to the position shown in FIG. 3.
1. Ice Cube Making Cycle The ice cube making cycle commences when the thermostatic feeler 58, which has been previously calibrated in conjunction with its motor control 56 (which may be any of several commercially available types such as Ranco lnc.s Type All), indicates that its high limit has been reached and that accordingly, all ice cubes which were previously frozen in receptacles 19 in the assembly 16 have been dislodged therefrom. This calibration can be made, for example, on the basis of several trial runs, whereby the temperature at which all the ice cubes are harvested is determined. Considering FIGS. 3 and 4 together with the electrical wiring diagram of FIG. 7, the higl1" activation of thermostatic control 56 closes a circuit between terminals 56a and 56c by virtue of arm 56. (Similar adjustment of thermostatic cycle control 94 causes arm 94 to contact free terminal 94b.) Arm 56 now completes a circuit for the raising of storage and plate assembly 20, that circuit being traceable from a source of positive potential, through closed closed switch 60, to terminal 64, along conductor 66, terminal 56a, arm 56, terminal 560, conductor 74, representative arm 42a of actuating toggle switch 42 (left position), terminal 72a, terminal 70a, a first winding of actuator motor 70 (not shown), common terminal 70b and over conductor 76 to a source of negative potential. In response to the activation of this winding of actuator motor 70, the storage and plate assembly 20 is gradually raised towards the position shown in FIG. 4, i.e., the ice cube making position. When the assembly 20 has been raised to a substantially horizontal position (FIG. 4), the link 36 deflects the toggle switch 42 and thereby deactivates the motor 70. With reference to the electrical diagram of FIG. 7, the arms 42a and 42b of toggle switch 42 are returned to their right positions. Since there is presently no complete circuit to the lowering" winding (not shown) of actuator motor between terminals 70b 700, the motor 70 remains off at this time, thereby stabilizing the assembly 20 in its horizontal position for the ice cube making cycle.
When the horizontal position of the assembly 20 shown in FIG. 4 has been reached, the water solenoid 54 is deactivated to terminate the introduction of supply water to the system, the pump 28 is turned on to transport water from reservoir 22 to recirculation chamber 44, and the hot gas solenoid 32 is deactivated so as to allow the refrigerant to perform the desired cooling function in the evaporator coils 18. These operations are achieved as follows: I-Iot gas solenoid 32 is deactivated in response to the upward movement of connecting arm 30 so that springloaded toggle switch 34 can return to its up position. Since the arm 30 is coupled to the assembly 20 by means of slotted member 31 (see FIGS. 1 and 3) and has collar 33 rigidly mounted on it, the arm moves upwardly when slotted member 31 contacts collar 33 as the assembly 20 is raised. The switch 34 returns to its up position, whereby the coolant has a narrower passageway (not shown) into the coolant coils 18, and accordingly performs its requisite cooling function. The electrical effect of this upward movement of arm 30 is indicated by virtue of toggle switch arm 34 moving from terminal 34b to terminal 34a in FIG. 7. This breaks the operating circuit for the activation of hot gas solenoid 32, said circuit having been traceable froma source of positive potential over closed switch 60, terminal 64, conductor 78, arm 34, terminal 34b, conductor 80, terminal 84, and solenoid 32 to a source of negative potential.
The water solenoid 54 is also deactivated at this time by the same upward movement of the arm 30 referred to immediately above. When the toggle switch 34 returns to its up" position, the arm 34 (FIG. 7) breaks the circuit previously traced out through hot gas solenoid 32; this same interruption serves also to deactivate water solenoid 54 which had been energized over the same circuit path up to terminal 34band thence through water solenoid 54 also to a negative potential source.
Water pump motor 28 had, up to this time, been deactivated, thus temporarily halting the water recirculation system. However, when the assembly 20 is returned to the horizontal position indicated in FIG. 4, the upward positioning of toggle switch 34, indicated in FIG. 7 by the contacting of terminal 34a by arm 34, recommences the water recirculation by virtue of activating water pump motor 28. The circuit for activating water pump motor 28 is traceable from the source of negative potential through the pump motor 28, and thence across conductor 82, terminal 34a, arm 34 in the up position, conductor 78, terminal 64, and through closed switch 60 to the source of positive potential. When the pump motor 28 is thusly reactivated, it begins to circulate water from reservoir 22 through conduit 46 and out from the pump 28 through pipe 48 into the recirculation chamber 44. Continuous pumping action during the ice cube making cycle drives the recirculated wter from the recirculing chamber 44 and into each of the plurality of oval shaped header tubes 52 (see FIGS. 2, and 6). Since the header tubes 52 are plugged at their right-hand ends (see plug element 53 in FIG. 5), the water is driven upward from the header tubes 52 and into the various ice cube freezing receptacles 19, as indicated by the arrows in the receptacles 19 in FIG. 4. As a result of such upward forcing of the recirculated water, freezing commences on the interior top and side walls of the receptacles 19. As pre- ,..viously mentioned, a great deal of this upwardly directed water spray begins to freeze immediately; however, the portion of water which does not so freeze at the outset is retained in the recirculation system by virtue of dropping through orifices 24b (FIGS. 2 and 6) and thence into the reservoir 22 of the assembly 20. Continued recirculation in this manner causes ice to gradually build up within each of the receptacles 19, thereby forming the desired ice cubes.
As the ice cubes are so formed, the temperature in the vicinity of the ice cube forming receptacles 19 is continuously reduced. For example, when the ice cube making cycle commences, atypical illustrative temperature in this vicinity is approximately 45 Fahrenheit (F.) However, as the ice cube making cycle nears its completion, with ice cubes almost fully formed in all of the receptacles 19, a typical illustrative temperature in the vicinity thereof is approximately 32 F. By appropriate adjustment of thermostatic controls 56 and 94, recognition of such temperature reduction by the thermostatic feeler 58 (and similar elements, not shown, for control 94) is arranged to trigger control 56. (While control 56 directly controls the positioning of storage assembly by controlling actuator motor 70, cycle control 94 is also thermostatically responsive to set the overall temperature limits on the ice cube making and harvesting cycles. Thus, control 94 can illustratively be set at temperatures between 0 F. and 55 F. to determine the cycle durations in conjunction with control 56.) This recognition in effect signals the end ofthe ice cube making cycle and the commencement ofthe harvesting" cycle.
2. Harvesting Cycle It will be recalled that once the predetermined low or relatively cold condition is recognized by a thermostatically controlled switch 56 and its associated feeler 58 and by second thermostatically controlled switch 94, harvesting of the ice cubes will commence by the lowering of storge tank and plate assembly 20, thereby removing plate 24 as the bottom closure of the ice cube receptacles l9 and permitting the ice cubes therein to fall by gravity once they are dislodged as described below.
This lowering of the assembly 20 occurs, with reference to FIG. 7, when representative switch arm 56 closes to the cold position represented by terminal 56b, and when thermostatic motor control arm 94 contacts its cold position terminal 94a. Since toggle switch 42, including arms 42a and 42b, is inits right position, a circuit is completed by the closure of arm 56 to terminal 56c and of arm 94 to terminal 940 to energize the lowering mechanism ofactuator motor 70. Specifically, this circuit is traceable from a positive potential source through closed switch 60, terminal 64, conductor 66,
terminal 56a, arm 56, terminal 56b, terminal 94a, arm 94, terminal 84, conductor 86, arm 42b, terminal 720, terminal 700, a lowering winding (not shown) of actuator motor 70, terminal b, and over conductor 76 to a source of negative potential. The assembly 20 is thus caused to lower, with bracket 57 pivoting around pin 53 on mounting plate 51 (FIGS. 3 and 4); the assembly 20 then drops from the horizontal position shown in FIG. 4 to the inclined position indicated in FIG. 3 under the control of motor 70. When this inclined position has been reached, it is noted that spring 38 is extended between pin 43 and connecting link 36. Arm 39, which is rigid with link 36, rotates about in a counterclockwise manner and deflects toggle switch 42 to deactivate the actuator motor 70 when the assembly 20 has reached the appropriate inclined position. Electrically, the toggle switch 42 and its associated arms 42a and 42b are thereupon switched to the left-hand positions, thereby de-energizing the lowering winding (between terminals 70b and 700) of actuator motor 70. Accordingly, the motor 70 is temporarily de-energized. The raising winding (between terminals 70a and 70c) is, however, not energized since there is no positive potential path connected to terminal 70a.
As the assembly 20 drops to the position shown in FIG. 3, slotted member 31 no longer-urges collar 33 on arm 30 upwardly. Accordingly, spring-loaded toggle switch 34 is switched to its lower position. This switching of arm provides a locking operating path for the hot gas solenoid 32, which path is independent of the positions of thermostatic arms 56 and 94. As previously mentioned, this solenoid acts as a. valve and serves to widen the passageway (not shown) ofthe coolant to the coolant coils 18 ofthe evaporator assembly 16. As a result of such valve-type unblocking the coolant (e.g., Freon l2, Freon 22, or other suitable refrigerant) actually acts as a heating agent within the same coils 18. As this hot gas passes through the coils 18, a slight melting action takes place within each of the ice cube receptacles 19, thereby tending to dislodge the ice cubes previously formed therein during the ice cube making cycle. As shown in FIG. 3, the ice cubes then drop from the receptales 19 onto the inclined plate 24, and thence, as shown by the illustrative dropping ice cubes 14, into the bin 12 shown in fragmentary form in FIG. 3 (see FIG. 1). From an electrical standpoint, as indicated in FIG. 7, the depressing of spring-loaded toggle switch 34 drops arm 34 in FIG. 7 from terminal 34a to terminal 34b. This seves to provide a locking path to activate the hot gas solenoid 32 over the path from positive potential and across closed switch 60, terminal 64, conductor 78, arm 34, terminal 34b, conductor 80, terminal 84, and through hot gas solenoid 32to negative potential.
Although the machine of the present invention makes an extremely efficient use of water which does not initially freeze in the receptacles l9, and of water applied to the plate 24 for de-icing purposes, there is still a need to permit a given charge of supply water to periodically enter the system. This occurs also in response to the lowering of the assembly 20 and the accompanying deflection of toggle switch 34 by arm 30. Water solenoid 54 is thereby activating to allow the supply water to enter (supply not shown) into connecting pipe 55 and through header 50 to'deposit the water along the width of the upper surface of plate 24. This water serves a dual function in that it both cleans the plate 24 of any ice thereon, and is also retained by the system both through the recapturing orifices 24b (FIG. 6) and by catch basin 26. Thus, all of the water which is introduced into this system under the control of water solenoid 54 ultimately finds its way to reservoir 22- in the assembly 20. In addition, due to the efficient water-retaining techniques of the present invention, eliminating wasteful drainage, the solenoid 54 can be adjusted to permit a much smaller charge of water to be introduced into the system than in prior art machines. Illustratively, the water charge utilized by the machine of this invention is as low as one-half that required by the prior art.
The water solenoid 54 is activated over an electrical path practically identical to that which activated hot gas solenoid 32. Thus, the path includes positive poten-' tial, closed switch 60, terminal 64, conductor 78, arm 34, terminal 34b, and through the water solenoid 54 to negative potential. With the assembly 20 in its lower, inclined position, as shown in FIG. 3, the harvesting of the ice cubes 14 within the receptacles l9 continues with hot gas being forced into the coils 18 under the influence of hot gas solenoid 32, and a predetermined charge of water being supplied to the system under the control of water solenoid 54. The thermostatic controls 5.6 and 94 are adjusted so that when a predetermined relatively high temperature is reached in the vicinity of the evaporator assembly I6, all the ice cubes 14 will have been dislodged from their partitions l9 and harvested into the bin 12. This temperature can also be determined by a few practice or trail runs of the system, and is generally around 45 F. When the control 56, through its thermostatic feeler 58 (and corresponding equipment, not shown, for control 94), recognizes that this relatively higher temperature has been reached,
controls 56 and 94 switch positions (see FIG. 7) and thereby effectively terminate the harvesting cycle. Referring to FIG. 7, when thermostatic control 56 recognizes this end-of-harvesting condition, its arm 56 moves away from contact 56b and comes into contact with terminal 560; similarly, arm 94 breaks away from terminal 94a and contacts terminal 94b. Initially, this prevents the application of positive potential to solenoids 32 and 54, although there is still positive potential for these elements by virtue of the position of arm 34. Positive potential is applied to the raising winding of actuator motor 70 between terminals 70a and 70b over a path through closed switch 60, terminal 64, conductor 66, terminal 560, arm 56, terminal 56c, conductor 74, arm 42a, terminal 72a, terminal 70a, the raising winding of actuator motor 70, terminal 70b, and through conductor 76 to negative potential. The assembly 20 thus begins to raise from the position shown in FIG. 3 to that shown in FIG. 4. When the position shown in FIG. 4 has been reached, toggle switch 34 is switched back to its up position in contact with terminal 34a (FIG. 7), and self-controlled toggle switch 42 is switched to its right-hand position, the latter serving to remove positive potential from the raising winding of actuator motor 70. Moreover, since there is no positive potential at this time at terminal 720 (due to the up" positioning of arm 34 and the respective positions of controls 56 and 94), the actuator motor 70 remains de-energized.
In addition, the upward movement of arm 34 from terminal 34b to terminal 34a now serves to de-energize both hot gas solenoid 32 and water solenoid 54. This permits the refrigerant to perform its cooling function in the cooling coils l8 and terminates the introduction of the supply charge of water, respectively. Finally, the water pump motor 28 is reactivated so as to begin the flow of water from the relatively cool supply in reservoir 22 to recirculating chamber 44 and header tubes 52, thus recommencing the ice cube making cycle as previously described.
It is of course understood that additional instrumentation can be provided to furnish additional sophisti cated controls within the skill of the art. For example, switch 90, which can be representative of a solenoid or other similar switch arrangement, can provide suitable pressure or manual safety control for the compressor or condensing unit 88 connected in series therewith. Similarly, switch 60 which is normally closed during both cycles described above, can be connected by means of a feeler 62 (FIGS. 1, 3 and 4) disposed within bin 12 to prevent excess accumulation and freezing together of the dislodged and harvested ice cubes therein. It is apparent that if switch or solenoid 60 opens the circuit next to its associated positive potential source, neither of the cycles previously described could take place.
Additional instrumentation can include wash switch 92 which is normally closed, but which can be opened manually to deactivate compressor 88 to permit, for example, sevicing of the system. Manual control of supply water can be achieved by means of switch 96, which, when closed, permits supply water to enter the system by activating water solenoid 54 when switch 34 is in contact with terminal 34a. This is accomplished over a path from positive potential and closed switch 60 and including terminal 64, conductor 78, arm 34, terminal 34a, conductor 98, now closed switch 96,'terminal 84, conductor 80, and through water solenoid 54 to negative potential. Other suitable instrumentation will be apparent to those skilled in the art to achieve various functional controls.
From the foregoing, it will be appreciated that the present invention finds it application in an automatic ice cube making machine of the type having a freezing cycle and a harvesting cycle and including an evaporator and freezer assembly 16 providing a cube-freezing chamber having a plurality of open bottom individual cells 19 disposed in heat exchange relationship with the coils 18 on the upper surface or wall 17 of the assembly 16. The storage tank and plate assembly 20 including top plate 24 provide a closure which is movable into a cell-closing position in which the closure substantially closes the open bottom of the plurality of cells 19 of the freezing chamber during the freezing cycle (see FIG. 4) and into a cube-discharge position in which the closure opens the bottom of the plurality of cells during the operable in conjunction with a two-position switch,
vated drive 70 for moving the closure into the cellclosing position of FIG. 4 and a second energization circuit to move the closure into the cube-discharge position of FIG. 3. The temperature-responsive control for initiating and terminating the freezing and harvesting cycles includes a first thermostatically activated switch 56 which is responsvlee to the temperature of the evaporator and freezer assembly or unit 16 and is operable in a first switch positon bridging contacts 56a and 56c and at a predetermined temperature to complete the first energization circuit from the source over toggle switch contacts 420, 72a to the drive for moving the closure to the cell-closing position. The first thermostatically activated switch 56 is operable over contacts 56a, 56b to initiate the freezing cycle and is responsive to a drop in temperature of the evaporator unit 16 to condition the control for initiating the start of the harvesting cycle. The control further includes the second thermostatically activated switch 94 which likewise is responsive to the temperature of the evaporator nit 16 and is operable at a lower predetermined temperature for initiating the harvesting cycle. Specifically, the second thermostatically activated switch 94 is operable at the lower predetermined temperature to complete the second energization circuit from the source to the electrically activated drive 70 for moving the closure to the cube-discharge position. Finally, the first thermostatically activated switch 56 is responsive to a rise in temperature of the evaporator unit 16 to terminate the harvesting cycle and to initiate the start of another freezing cycle.
It is to be understood that the above-described arrangements are illustrative of the application of the principles of the invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.
What is claimed is:
l. A machine for making ice cubes and having an ice cube making and an ice cube harvesting cycle comprising a collection bin for receiving said ice cubes, a freezing chamber for containing said ice cubes during said ice cube making cycle, an evaporator assembly in heat exchanging relation with said freezing chamber, storage assembly means including a reservoir for circulated water furnished to said freezing chamber during said ice cube making cycle and for supply water furnished to said machine during said ice cube harvesting cycle including plate means for acting as a bottom closure for said freezing chamber during said ice cube making cycle, water transporting means for circulating water to said freezing chamber, temperature responsive control means comprising first and second thermostatically actuated switches responsive to thedetection of a first predetermined relatively lower temperature in said freezing chamber for terminating said ice cube making cycle and responsive to the detection of a second predetermined relatively higher temperature in said freezing chamber for terminating said ice cube harvesting cycle and driving means responsive to said control means detecting said first predetermined relatively lower temperature for positioning said storage assembly means whereby said plate means directs said ice cubes dislodged from said freezing chamber into said collection bin during said ice cube harvesting cycle and responsive to said control means detecting said second predetermined relatively higher temperature for positioning said storage assembly means whereby said plate means said bottom closure position relative to said freezing chamber during said ice: cube making cycle.
2. A machine in accordance with claim l wherein said evaporator assembly includes a coil network for carrying a heat exchanging substance and including in addition heat exchange supervisory means responsive to said control means detecting said second predetermined relatively higher temperature for directing said substance into said coil network as a coolant during said ice cube making cycle and responsive to said control means detecting said first predetermined relatively lower temperature for directing said substance into said coil network as a heating agent during said ice cube harvesting cycle. v
3. A machine in accordance with claim 1 wherein said freezing chamber includes a plurality of inverted receptacles and an upper surface for supporting said evaporator assembly, wherein said plate means includes a plurality of apertures grouped to correspond with each of said receptacles, and wherein said water transporting means includes a recirculation chamber, a plurality of header tubes communicating with said recirculating chamber and with said receptacles through a first group of said apertures during said ice cube making cycle, and a pump responsive to the commencement of said ice cube making cycle for delivering water from said reservoir to said receptaclesthrough said recirculation chamber and said header tubes, whereby said water is forced through said first group of apertures and substantial quantities ofsaid water adheres in freezing relation to the interior of said receptacles, the remainder of said forced water being recaptured by a second group of said apertures for return to said reservoir.
4. A machine in accordance with claim 1 wherein said plate means includes plural recapturing orifices therethrough, including in addition water supply control means for introducing a predetermined charge of supply water into said water transporting means during said ice cube harvesting cycle, including means for depositing said charge of supply water onto said plate means for de-icing said plate means, wherein said storage assembly means includes catch basin means projecting beyond the end of said plate means for directing said supply water to said reservoir, whereby a portion of said charge of supply water enters said reservoir through said recapturing orifices and the remainder of said charge of supply water enters said reservoir through said catch basin means.
5. A machine in accordance with claim 2 wherein said control means includes at least one thermostatic unit having a feeler element responsive to the heating action of said heat exchanging substance during said ice cube harvesting cycle for energizing said driving means to elevate said storage assembly means whereby said plate means is brought into a closure relation with said evaporator assembly to terminate the introduction of said heat exchanging substance as a coolant, and responsive to the cooling action of said heat exchanging substance during said ice cube making cycle for energizing said driving means to lower said storage assem bly means whereby said plate means is removed from said closure relation with said evaporator assembly to terminate the introduction of said heat exchanging substance as a heating agent.
6. An automatic ice cube making machine of the type including a freezing chamber having a plurality of open bottom individual cells in heat exchange relation with a refrigerant evaporator; a closure plate movable be tween a cell-closing position whereby the closure plate substantially closes the open bottom of said plurality of cells during the freezing cycle of the evaporator and an ice cube discharge position whereby the closure plate opens the bottom of the plurality of cells during the harvest cycle of the machine; motor means for moving said closure plate between cell-closure position and ice cube discharge position; tank means for holding a volume of water substantially equal to the volume of water required for producing the ice cubes, supply means for controlling the supply of water to said tank; recirculation means for recirculating the water in said tank through the plurality of cells during said freezing cycle; a source of potential; and control means responsive to a predetermined temperature in said freezing chamber for terminating the freezing cycle of said evaporator and connecting said source of potential across said motor means to energize said motor means to move said closure plate to said ice cube discharge position,
wherein said control means'includes a first thermostatically actuated switch connected to said source of potential and a second thermostatically controlled switch serially connected between said first thermostatically controlled switch and said motor means, whereby said first thermostatically controlled switch connects said source of potential across said second thermostatically controlled switch when the temperature in said freezing chamber reaches a first temperature above said predetermined temperature, and said second thermostatically controlled switch connects said source of potential across said motor means when the temperature in said freezing chamber reaches said predetermined temperature.
7. In an automatic ice cube making machine of the type having a freezing cycle and harvesting cycle and including an evaporator unit, a cube-freezing chamber having a plurality of open'bottom individual cells disposed in heat exchange relation with said evaportor unit, a closure movable into a cell-closing position in which said closure substantially closes the open bottom ofsaid plurality of cells of said freezing chamber during said freezing cycle and into a cube-discharge position in which said closure opens the bottom of the plurality of cells during said harvest in cycle and an electrically activated drive for moving said closure between said cell-closing and cube-discharge positions, the improvement comprising a temperature-responsive control for initiating and terminating said freezing and harvesting cycles comprising a source of potential, a first thermostatically activated switch responsive to the temperature of said evaporator unit and operable in a first switch position to connect said drive to said source for moving said closure to said cell-closing position to start said freezing cycle, said first thermostatically activated switch being responsive to a drop in temperature of said evaporator unit and operable in a second switch position to condition said control for the initiation of the start of said harvesting cycle and a second thermostatically activated switch responsive to the temperature of said evaporator unit and operable to initiate said harvesting cycle, said first thermostatically activated switch being responsive to a rise in temperature of said evaporator unit to initiate the start of the next freezing cycle.
8. In an automatic ice cube making machine according to claim 7, a water supply, means for circulating water from said supply over said closure and means operable in response to movement of said closure into and out of said cell-closing position for controlling the circulation of water from said supply to said closure.
9. In an automatic ice cube making machine according to claim 8, said controlling means being arranged to interrupt the supply of water to said freezer chamber when said closure is in said cell-closing position.
10. In an automatic ice cube making machine according to claim 7, a hot gas supply and means operable under control of said second thermostatically activated switch for controlling the flow of hot gas from said hot gas supply into heat exchange relation to freezing chamber.
11. In an automatic ice cube making machine according to claim 10, said controlling means being arranged to initiate flow of hot gas into heat exchange to said freezing chamber under control of said second thermostatically activated switch and when said closure is in said cube-discharge position.
12. In an automatic ice cube making machine of the type having a freezing cycle and a harvesting cycle, an evaporator unit, a cube-freezing chamber having a plurality of open bottom individual cells disposed in heat exchange relation with said evaporator unit, a closure movable into a cell-closing position in which said closure substantially closes the open bottom of said plurality of cells of said freezing chamber during said freezing cycle and into a cube-discharge position in which said closure opens the bottom of the plurality of cells during said harvest cycle, a source of potential, an electrically activated drive for moving said closure between said cell-closing and cube-discharge position, a twoposition switch actuated in response to movement of said closure between said cell-closing and cubedischarge positions for establishing a first energization circuit between said source and said drive to move said closure into said cell-closing position and a second energization circuit from said source to said drive to move said closure into said cube-dischargbe position and a temperature-responsive control for initiating and terminating said freezing and harvesting cycles including a first thermostatically activated switch responsive to the temperature of said evaporator unit and operable in a first switch position and at a predetermined temperature to complete said first energization circuit from said source to said drive for moving said closure to said cell-closing position, said first thermostatically activated switch being operable to initiate said freezing cycle and being responsive to a drop in temperature of said evaporator unit and operable in a second switch position to condition said temperature-responsive control for the initiation ofthe start of said harvesting cycle and a second thermostatically activated switch responsive to the temperature of said evaporator unit and operable at a lower predetermined temperature for initiating said harvesting cycle, said second thermostatically activated switch being operable at said lower predetermined temperature to complete said second energization circuit from said source to said drive for moving said closure to said cube-discharge position, said first thermostatically activated switch being responsive to a rise in the temperature of said evaporator unit to terminate said harvesting cycle and to initiate the start of another freezing cycle.
13. In an automatic ice cube making machine according to claim 12, a water supply, means for depositing water from said supply onto said closure and means operable in respnose to movement of said closure into said cube-discharge position for initiating the supply of to terminate the supply of water onto said closure.
15. In an automatic ice cube making machine according to claim 12, a hot gas supply and means operable under control of said second thermostatically activated switch for initiating the flow of hot gas from said hot gas supply into heat exchange relation to freezing chamber at the start of said harvesting cycle.
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