US3016718A

US3016718A - Ice level sensor

Info

Publication number: US3016718A
Application number: US856518A
Authority: US
Inventors: Robert R Malone
Original assignee: Dole Valve Co
Current assignee: Dole Valve Co
Priority date: 1959-12-01
Filing date: 1959-12-01
Publication date: 1962-01-16
Anticipated expiration: 1979-01-16

Description

Jan. 16, 1962 Filed Dec. 1, 1959 R. R. MALONE ICE LEVELSENSOR 3 Sheets-Sheet 1 fDVEZ'L DP Rater-t R. Ma. (a7z&

Jan. 16, 1962 Filed Dec. 1. 1959 R. R. MALONE ICE LEVEL SENSOR 3 Sheets-Sheet 2 fnrenfar' R afieri' R Na lane Jan. 16, 1962 R. R. MALONE 3,016,718

ICE LEVEL SENSOR Filed Dec. 1, 1959 5 Sheets-$heet 3 I fnrenfar' [g] Raer'fi R Mal/071a WW W by Fffg 3,016,718 ICE LEVEL SENSQR Robert R. Malone, Des Plaines, lll., assignor to The Dole Valve Qompany, Morton Grove, ill, a corporation of Illinois Filed Dec. 1, 1959, Ser. No. 856,518 7 Claims. ((1 62-137) This invention relates to an ice making apparatus and more particularly relates to an ice making apparatus including an ice tray having ice molds formed along the pivotal axis thereof and facing outwardly therefrom and to a means for sensing the level of ice blocks within an ice block collection tray and to a means for controlling the operation of the apparatus as a function of that level.

More specifically this invention is directed to a so called two sided ice tray which is rocked from one extreme pivoted position to another during each freezing cycle and wherein the heat of water filling an upwardly facing bank of ice molds is effective to break the bond between ice blocks within a collection tray disposed beneath ice trays and have included both horizontally and vertically movable sensing elements which may be moved into abutment with the ice blocks within the collection tray. Such sensing elements are generally associated with switches, generally of a somewhat complex nature, which are effective to energize and deenergize some or all of the components of the ice making apparatus as a function of the degree of pivotal movement of the sensing element.

Many of these sensing elements have, however, not proved entirely satisfactory in sensing the level of ice blocks inasmuch as they become buried with the ice blocks during an ejection cycle so that their reciprocable pivotal movement is prevented.

To obviate the disadvantageous characteristics of prior types of ice level sensing mechanisms i have devised a mechanism which is operable to sense the level of ice blocks in a collection tray in which the possibility of having the sensing arm buried by cubes being ejected from the ice tray is nearly en irely eliminated.

The sensing means includes generally a level sensing which is pivotally movable through a vertical plane and which is disposed on one side of the longitudinal axis of the ice tray. Means are associated with the sensing element to raise and lower the element with respect to the collection tray and other means are operable to prevent lowering of the sensing element to the collection tray when the ice tray is pivoted to a position to permit ejection of ice blocks from the side thereof adjacent which sensing element is disposed.

A mechanical linkage interconnects the sensing element with the ice tray so that the sensin" arm is positively rockably moved upon pivotal movement of the ice tray.

in the illustrated embodiment of the invention a cam is mounted on the sensing element at the pivotal axis thereof which is operable to effect longitudinal movement of the operating member of an electrical switch assembly.

The switch assembly comprises generally a movable contact element and an associated thermally sensitive power element which, in turn, has a power member which is extensible therefrom upon predetermined ambient temperature conditions about the sensing element.

The sensing element has a resistor heater wound therearound so that upon energization of the heater, the power member will move extensibly from the element and contact the movable contact of the electrical switch to move Upon such movement of the movable contact, the motor Patented Jan. 16, E932 means for driving the pivotal ice tray and the tray filling means will be deenergized to prevent further operation of the ice making apparatus. Movement of the switch contact into and out of a closed circuit position is effected by means of a thermally sensitive power unit which is operable as a function of the rate of freezing of water within the ice tray.

A latch mechanism interconnects the operating member with the movable contact to prevent movement of the switch contact to closed circuit position whenever the level of ice blocks within the collection tray reaches a predetermined point and is so sensed by the sensing element.

It is therefore a principal object of the present invention to provide an improved mean for sensing the level of ice blocks within a collection tray of an ice making apparatus and to a means for controlling the operation of such an apparatus as a function of the level.

Another object of the invention resides in the provision of a novel means for preven ing malfunctioning of the ice sensing element due to burial of the element by ice blocks being ejected from the ice tray.

A still further object of the invention is directed to the provision of a simple and efficient means of controlling the operation of electrically energizable components as a function of the level of ice blocks Within an ice block collection tray as sensed by the ice level sensing element.

Yet another object of the invention is the provision of a simple mechanical linkage for raising and lowering an ice sensing element as a function of the pivoted position of a pivotal ice tray.

These and other objects of the invention will become apparent from time to time as the following specification proceeds and with reference to the accompanying drawings. wherein:

FIGURE 1 is a side elevational view of an ice making apparatus constructed in accordance with the principles of the present invention;

FIGURE 2 is a vertical sectional view taken along the lines TTll of FIGURE 1;

FIGURE 3 is a fragmental partial elevational and partial sectional view of the switch control means;

FIGURE 4 is a fragmental side elevational view which is similar in nature to FFGURE 3, but which shows the operating element of the switch in a latched position; and

FIGURE 5 is a diagrammatic view of the wiring circuit which might be employed to effect operation of the ice m king apparatus illustrated in FIGURES 1 through 4.

Referring initially to FIGURES l and 2 of the drawings. a pivotal ice tray 10 is mounted on a shaft 11 for corotatable movement therewith; which shaft is, in turn, journaled for pivotal movement in an insulated side wall 12 of a freezing compartment of a normal household refrigerator or the like. A motor 13 is diagrammatically illustrated as being connected to the input end of the shaft 11 and may be of any suitable type which can effect a preselected angular movement of the shaft 11 and tray 10 in each of two opposite rotational directions at preselected intervals of time.

The ice tray 10 comprises generally a confining wall 15 which has upwardly turned ends 16 formed integral therewith and opposite ends thereof. The confining wall 15 is bent along its longitudinal axis as at 18 to form two elongated opposite facing

legs

19 and 20..

A common wall 21 (so called because it is common to ice molds formed on opposite sides thereof, as will hereinafter be described) constitutes an obtuse bisectrix of the elongated legs 19 and 29 and extends fro-m the vertex 18 of those legs and is secured at its opposite ends to the upstanding end Walls 16.

A plurality of partitioning wall or fins 17 are equally spaced along the common wall 21 transversely thereto, and serve to divide the ice tray 10 into a plurality of separate ice molds.

Inasmuch as ejection of ice blocks from the ice tray is effected by means of heat transfer through the walls of the ice tray, the tray is constructed of a good heat conducting material and is so formed that a large percentage of the ice blocks frozen in individual molds in the ice tray lie on surfaces adjacent the common wall 21.

When the ice tray 10 is in the position illustrated in FIGURE 2, the upwardly facing bank of ice molds are filled with water from a time-fill valve 9 upon energization thereof. Upon freezing of the water in the upwardly facing bank of ice molds the tray is rotated approximately 140 until the bank of molds which were formly facing downwardly are disposed in a filling position. At such time, relatively warm water is directed to the upwardly facing molds and the heat of this water flowing into the upwardly facing molds melts the surface of the ice blocks within the downwardly facing molds so that they are permitted to drop from the ice tray 10. A collection tray 30 is disposed beneath the ice tray 10 which is adapted to collect and contain the ice blocks thus ejected from the ice tray 10.

As illustrated in FIGURE 5, the motor 12 and the timefill valve 9 are energized through a switch 40a. The switch 40a has a stationary contact 41 and a snap blade 42, which constitutes the movable contact of the switch and which has its opposite ends received within opposed seats 43 in the casing 40 of the switch 40a. The plunger 44 has a pair of

abutment members

45 and 46 connected thereto and extending transversely thereof which are spaced along the longitudinal axis thereof and which are adapted to engage the snap blade 42 to snap that blade between the full and broken line position illustrated in FIGURE 5.

As illustrated in FIGURES 4 and a thermally sensitive power unit 48 is mounted within the wall 12 of the freezing compartment and has a temperature sensitive portion 49 which is disposed within the freezing compartment, a guide portion 50, and a power member 51 which is guided for reciprocable movement within the guide portion 50 and which is extensible from the guide upon heating of" the temperature sensing portion 49 above a predetermined temperature. The outermost end of the power member 51 abuts a flange 53 of the plunger 44; which flange extends transversely of the longitudinal axis of the plunger 44. A resistor heater 55 is wound about the temperature sensitive portion of the power unit 48 and, like the motor 13, is energizable through the switch 40a. The thermally sensitive power unit 48 is of a type which is well known in the art and, accordingly, it will sufiice to state that spring means are disposed within the guide portion thereof which are effective to bias the power member 51 to retracted position with respect to the guide 50 "so that upon cooling of the sensing portion 49 thereof, the power member 51 will be retracted.

Accordingly, when the snap blade 42 is in the position illustrated in full lines in FIGURE 5 the motor 13, valve 9, and resister heater 55 will be energized. The timefill valve will not begin'to effect filling of the tray until the tray has completed or'nearly completed a pivotal cycle; a hystere-tic effect being incorporated therein. However, this valve, per se forms no part of the present invention and so is not hereafter more fully described. Energization of heater 55 will heat the sensing portion 49 to a critical temperature to effect extensible movement of the power member 51. Extensible movement of member 51 will act to depressionally move the plunger 44 within the casing 40, but movement of the snap blade will not be effected since the plunger 44 is slidably received thereby. However, when the member 45 moves into engagement with the snap blade 42, the blade will then be snapped from the full-line to the broken-line position illustrated in FIGURE 5. Such movement of the blade 42 will act to deenergize the motor 13, valve 9, and resistor heater 55. Upon deenergization of the heater 55, the thermal sensing portion 49 of power unit 48, which is disposed within the freezing compartment, will cool and the power member 51 will be retracted. A spring 58 is disposed within the casing 49 and urges the plunger 44 to move extensively from the casing, so that upon retraction of power member 51 the plunger 44 will be urged outwardly of the switch casing.

A limit switch is associated with the motor 13 in a well known manner, which has a function of shutting off the motor when the ice tray 10 has been rotated in either direction to the desired position.

With particular reference to FIGURES 3 and 4 of the drawings, a latch 60 is employed to control operation of the switch 40. The latch 60 comprises generally an upstanding leg 61 having a curled finger 62 in the outer end thereof. The leg 61 is preferably formed of metal or some other material having some resiliency so that movement of the leg 61 from the position illustrated in FIG- URE 3 to the position illustrated in FIGURE 4 can be effected. The curled finger 62 is so disposed relative to the flange 53 of the plunger 44, that when the leg 61 is in a normal unstressed position, as is shown in FIG- URE 4, the finger 62 is disposed in the path movement of the flange 53 when the plunger 44 is urged to move extensibly from the switch casing 40. As is more clearly illustrated in FIGURE 5, when the latch 60 is disposed in this position, the plunger 44 is prevented from moving extensibly from the casing 40 a suflicient degree to effect movement of the snap blade 42 from the brokenline to the full-line position so that energization of the several components of the ice making apparatus is prevented.

An arm 63 extends outwardly from and is formed integrally with the leg 61 and extends therefrom, at a point spaced from the point of connection of the leg 61 with the bracket 65 (upon which the switch casing 40 is mounted) so that when the outermost end of arm 63 is moved toward the right, as viewed in the drawings, the leg 61 will be moved to the position illustrated in FIG- URE 3 so that the curled finger 62 will not be disposed in the path of movement of the flange 53. The bracket 65 is, of course, connected to the wall 12.

An operating member or push rod 70 is slidably disposed within the insulated side wall 12 of the freezing compartment and has one end disposed in juxtaposition to the free end of the arm 63 so that movement thereof will effect operation of the latch 60 in the manner above described. Movement of the operating member 70 is effected as a function of the level of ice within the collection tray 30 in a manner which will hereinafter become apparent.

A bracket 71 is aifixed to the inner side of the freezing compartment and has a pair of spaced,

outturned legs

72 and 73 formed integrally therewith. A horizontally extending portion 74 of an ice sensing element 75 is journaled for pivotal movement within the

legs

72 and 73 and is formed integrally with an ice level sensing arm 76 which, in turn, terminates in a sphere 77.

An arcuately shaped abutment member 79 is keyed to the level sensing element 75 at the horizontally extending portion 74 thereof and is cooperable with a cam 86 secured to the adjacent end of the ice tray 10 to effect raising and lowering of the ice sensing arm 76.

As best shown in FIGURES 1 and 2, the cam 80 is so shaped that when the ice tray 10 is rotated in a clockwise direction, as viewed in FIGURE 2, the abutment member 79 will ride along the cam surface and will itself rotate in a clockwise direction to move the sensing arm 76 from the full-line to the broken-line position illustrated in FIGURE 1. Upon return movement of the ice tray 10 the sensing arm 76 will drop to its initial position under its own weight. Pivotal movement of the sensing element 75 is thus effected.

A cam 82 is also keyed to the horizontally extending portion 74 of the ice level sensor 75' and this cam is adapted to elfect longitudinal-movement of the operating member '70. One end of the operating member 70 is rounded and is cooperable with the cam surface of the cam 82 and is maintained in engagement with that surface by means of a compression spring 83 which is seated at one end against the wall 12 and, at the opposite end thereof, against an annular shoulder 84 of the member 70. The cam 82 is so formed that whenever the sensing element 75 is disposed in angular segment A, as illustrated in FIGURE 1, the operating member 70 will be biased to the position illustrated in FIGURE 4 by the spring 33 to permit the leg 61 to move to the position also illustrated in FIGURE 4. In any other position of the sensing element 75 (that is when the sensing arm 76 is disposed in angular segments B and C as shown in FIGURE 1) the operating member 70 will be maintained in the position illustrated in FIGURE 3 so that the curled finger as of the latch 60 will not be disposed within the path of movement of the flange 53.

Assuming that the various parts of the apparatus are initially in the positions illustrated in full lines in FIG- URES 1, 2, 3 and 5, the operation of the device will be substantially as follows: with the snap blade 42 seated against the stationary contact 41 the motor 13, valve 9, and the heater 55 will be simultaneously energized. The motor will act to rotate the ice tray 10 in a clockwise direction as viewed in FIGURE 2 and it will be shut off when the ice tray has reached its proper extreme clockwise rotated position by opening of the limit switch associated therewith.

During the interval when the ice tray 10 is rotating to its extreme clockwise rotated position the sensing arm 76 will be raised to the broken-line position illustrated in FIGURE 1 by coaction of the abutment member 79 and the cam 8t into angular segment B.

Thus when ice blocks are ejected from the side of the tray adjacent the arm 76 burying of the arm is prevented since it is held in a raised position.

After the tray in has rotated to this extreme clockwise rotated position the time delay fill valve 9 will fill the upwardly facing bank of ice molds with water and heat or" water flowing into these molds will serve to efiect ejection of ice blocks from the downwardly facing molds. Shortly thereafter, the heat sensitive portion 49 of the power unit 48 will have been heated to a sufiicient degree to effect movement of the power member 51 to, in turn, move the plunger 44 inwardly against the opposing biasing force of spring 58 to snap the blade 42 to the broken-line position illustrated in FIGURE 5.

It will be understood that when ice blocks are being ejected from the ice tray on the side thereof adjacent the sensing arm 76, the arm 76 is maintained in its raised position. so as not to be buried by ice blocks falling from the ice tray to the collection tray 39.

The thermal sensitive power unit 48 may be suitably insulated exteiiorly of the heater 55 or have a suitable thermally expansible material disposed therein so that the thermally expansible material will contract upon cooling at approximately the same rate as the water within the ice tray freezes. The particular characteristics of such a power unit do not, however, form any part of the present invention and so are not described herein in detail.

Accordingly, upon freezing of the water within the upwardly facing bank of ice molds, the power member 51 will retract and the plunger 44 will be urged outwardly of the switch casing as by the spring 58. It will be noted that when the sensing arm 76 is maintained in the raised position, the operating member 7! is maintained in the position illustrated in FIGURE 3 so that the curled finger 62 of the latch on is not disposed in the path of return movement of the flange 53. As a result, the spring 58 will act to urge the plunger 44 toward the position illustrated in FIGURE to snap the blade 42 from the broken-line to the full-line position to again effect energization of the various components of the ice making apparatus. The cycle will then again be repeated and the reversible motor 13 will act to rotate the ice tray 10 back to the position illustrated in FIGURE 2.

Upon rotation of the ice tray Id back to the position illustrated in FIGURE 2, the sensing arm 76 will be permitted to drop toward the collection tray iii) to sense the level of ice blocks therein. If the arm "id drops all the way to the position illustrated in full-lines in FIGURE 1 the cycle of operation of the device will simply be continued. If, however, the level of ice blocks within the collection tray 30 is sufiiciently high to limit downward movement of the sensing arm 76 so that it is prevented from moving into angular segment C the operating member 70 will be disposed on the low surface of the cam 82 so that the leg 61 of the latch 69 will, under its own resiliency, be positioned with its curled finger 62 in the path of return movement of the flange 53. in such a case, the cycle of operation of the ice making apparatus will be terminated. That is, heating of the heater 55 and rotation of the tray 10 through energization of the motor 13 will be prevented since upon cooling of the element 4% and consequent retraction of the power member 51 the plunger 44 will be prevented from returning to an extended position with respect to the switch casing 40 as a result of the abutment of the flange 53 with the finger 62.

Further operation of the ice making apparatus will thus be prevented until such time when the ice block level within the tray 3'3 is lowered to permit the sensing arm '76 to drop to the position illustrated in full-lines in FIGURE 1. Such movement of the sensing arm 7 6 will act through the cam 82 to move the operating member 7% toward the right, as viewed in FIGURE 3, to unlatch the curled finger 62 from the flange 53.

It will further be understood that during the interval when the tray 16 is in a position to permit ejection of ice blocks from the side of the tray adjacent the arm '76 and the arm 76 is maintained in a raised position in angular segment B, the finger 62 will be maintained in an unlatch position relative to the flange 53.

I have thus provided a simple mechanical linkage for controlling the operation of an ice making apparatus as a function of the level of ice blocks Within a collection tray in which malfunction of the ice block level sensor is nearly entirely eliminated inasmuch as the sensing arm is prevented from being buried.

It will be understood that this embodiment of the inven" tion has been used for illustrative purposes only and that various modifications and variations of the present invention may be effected without departing from the spirit and scope of the novel concepts thereof.

I claim as my invention:

1. An ice making apparatus comprising: a support disposed within a freezing compartment; an ice tray pivotally mounted within said support having outwardly facing ice molds formed along the pivotal axis thereof; a collection tray; means for filling upwardly facing ice molds with water and ejecting ice blocks from downwardly facing molds into said collection tray; motor means for pivoting said ice tray to selectively dispose each of said molds in filling and ejecting positions; level sensing means having a member pivotally mounted on said support and movable into engagement with the ice blocks within said collection tray, operable to control operation of said motor means as a function of the ice block level sensed by said member; said member being mounted for pivotal movement only on one side of the pivotal axis of said ice tray; means for moving said member into and out of level sensing position; and means preventing movement of said member to sensing position when said tray is in a position to perm-it ejection of ice blocks from said one side of the pivotal axis thereof.

2. An ice making apparatus as recited in claim 1 wherein said member is mounted for pivotal movement about a horizontal axis and is raised and lowered into and out of ice block level sensing position as a function of the relative pivoted position of said ice tray.

3. An ice making apparatus comprising: a support disposed within a freezing comparnr at; an ice tray pivotally mounted within said support having outwardly facing ice iolds formed along the pivotal axis thereof; a collection tray; means for filling upwardly facing ice molds with Water and ejecting ice blocks from downwardly facing molds into said collection tray; motor means for pivoting said ice tray to selectively dispose each of said molds in filling and ejecting positions; level sensing means having a member pivotally mounted on said support about a substantially horizontal axis and movable into engagement with the ice blocks within said collection tray, operable to control operation of said motor means as a function of the ice block level sensed by said member; said member being mounted for pivotal movement only on one side of the pivotal axis of said ice tray; means for moving said member into and out of level sensing position; an abutment element forming an extension from said member; and a cam connected to said ice tray and cooporable with said element to prevent movement of said member into engagement with the ice blocks within said collection tray when said ice tray is in a position to permit ejection of ice blocks from said one side of the pivotal axis thereof.

4. An ice making apparatus comprising a support; an ice tray mounted on said support within a freezing cornpartment; a collection tray; control means for filling said ice tray with water and for ejecting frozen ice blocks therefrom into said collection tray; a sensing element pivotally mounted on said support about a horizontal axis having an arm extending outwardly therefrom; means for lowering said arm from a raised position into engagement with the ice blocks within said collection tray; the level of ice blocks being determinative of the degree to which said arm pivots from its raised to its lowered position; a cam connected to said element on the pivotal axis thereof; switch means controlling energization of said control means having a movable operating element, said operating element being movable to open and close the circuit of said switch means; means for effecting movement of said operating element as a function of the rate of freezing of water within said freezing compartment; an operating member mounted on said support and engaging said cam, said operating members relative position being determined by the pivoted position of said sensing element; and latch means engageable with said operating element and movable by said operating member for preventing circuit closing movement of said operating element as a function of the relative position of said operating member.

5. An ice making apparatus comprising a support; an ice tray disposed within a freezing compartment pivotally mounted on said support having outwardly facing ice molds formed along the pivotal axis thereof; a collection tray; control means for filling upwardly facing ice molds with water and ejecting ice blocks from downwardly facing molds into said collection tray; motor means for pivoting said tray to selectively dispose each of said molds in filling and ejecting positions; a sensing element pivotally mounted on said support about a horizontal axis having an arm extending outwardly therefrom; means for lowering said arm from a raised position into engagement with the ice blocks within said collection tray, the level of ice blocks being determinative of the degree to which said arm pivots from its raised to its lowered position; a cam connected to said element at the pivotal axis thereof; switch means controlling energization of said control means having a movable operating element which is positionable to open and close an energizing circuit through said switch means; means for effecting movement of said operating element as a function of the rate of freezing water Within said freezing compartment; an operating member mounted on said support and engaging said cam, said operating members relative position being determined as a function of the pivoted position of said first mentioned element; and latch means engageable with said operating element and movable by said operating member for preventing circuit closing movement of said operating element as a function of the relative position of said operating member.

6. An ice making apparatus comprising: a support disposed within a freezing compartment; an ice tray pivotally mounted within said support; a plurality of ice molds formed along first and second sides of the pivotal axis of said ice tray; drive means for pivoting said ice tray between first and second positions, said ice molds on said first side of said ice tray being adapted to face downwardly and eject ice when said tray has been pivoted to said first position and said ice molds formed on said second side of said ice tray being adapted to face downwardly and eject ice when said ice tray has been pivoted to said second position, means for filling said ice molds on said first side of said ice tray with water when said ice tray is in said second position and for filling said ice molds on said second side of said ice tray when said ice tray is in said first position; a collection tray disposed beneath said ice tray for collecting ice ejected from said ice molds; means for sensing the level of ice in said collection tray, said level sensing means being operative only when ice is being ejected from said ice molds on said first side of said ice tray, said level sensing means being displaced away from the ice which is ejected from the molds on said first side of said ice tray.

7. An ice making apparatus comprising: a support disposed within a freezing compartment; an ice tray pivotally mounted within said support; a plurality of ice molds formed along first and second sides of the pivotal axis of said ice tray; drive means for pivoting said ice tray between first and second positions, said ice molds on said first side of said ice tray being adapted to face downwardly and eject ice when said tray has been pivoted to said first position and said ice molds formed on said second side of said ice tray being adapted to face downwardly and eject ice when said ice tray has been pivoted to said second position, means for filling said ice molds on said first side of said ice tray with water when said ice tray is in said second position and for filling said ice molds on said second side of said'ice tray when said ice tray is in said first position; a collection tray disposed beneath said ice tray for collecting ice ejected from said ice molds; means for sensing the level of ice in said collection tray, said level sensing means being operative only when ice is being ejected from said ice molds on said first side of said ice tray, said level sensing means being displaced away from the ice which is ejected from the molds on said first side of said ice tray, said level sensing means being operable to control energization of said drive means as a function of the ice level within said collection tray.

Heath Jan. 22, 1957 Reddi Aug. 23, 1960