US 3254505 A
Description (OCR text may contain errors)
June 7, 1966 c. E. DE TURK 3,254,505
FLEXIBLE TRAY ICE MAKER MECHANISM Filed Sept. 27, 1960 42 42 III INVENTOR. C/ILV/A/ 1.. Di 701W! x; OVWW United States Patent 3,254,505 FLEXIBLE TRAY ICE MAKER MECHANISM Calvin E. De Turk, Cranbury, N.J., assignor, by mesne assignments, to Philco Corporation, Philadelphia, Pa., a corporation of Delaware Filed Sept. 27, 1960, Ser. No. 58,769
1 1 Claim. (Cl. 62-353) This invention relates to an ice maker, particularly of the type which produces ice in a flexible tray, and has to do with drive means for moving tray structure to perform various charging, freezing, and discharging operations. A tray structure of the type contemplated herein is shown in the abandoned application of I. C. Courson, Serial No. 44,335, filed July 21, 1960, entitled Ice Maker and Method of Using and Controlling the Same, and the apparatus disclosed and claimed herein is shown in the copending disclosure of the present applicant Serial No. 30,536, filed May 20, 1960, and issued October 2, 1962, as Patent No. 3,056,271, entitled Ice Maker. Both of said copending disclosures are assigned to the assignee of this .invention.
It is an object of the invention to provide an ice maker, complete with drive, which is compact and small, this being important since the tray and drive unit is desirably installed in a domestic refrigerator and the space provided by and in such a refrigerator is valuable. It is also desired to construct the mechanism so that it can produce large quantities of ice, and it is further required that the device be able to operate with a minimum of service and repair, particularly when it is installed in a household appliance. Still further, the drive mechanism must op perate at subfreezing temperatures, without lubricants as used in conventional drives; the lubricant would-be likely at the required subfreezing temperatures to become viscous or solid.
Additional, important requirements have to do with certain successive movements of the tray. It is desired that the mechanism be able, in a first operating phase, to overturn a normally upwardly facing tray and-to cause loosening of the ice therein. During this phase it is necessary, for proper loosening of the ice, to apply a forcible flexing motion to the tray, which motion must occur between precise positions of the tray and must be relatively slow when the drive is small and compact as desired Subsequently, however, the drive mechanism should return the tray rapidly, and again with accuracy, to a position where refilling of the tray with water can be started. Speed is desired since on the one hand the refilling is an operation which again consumes a certain amount of time and since on the other hand the complete operating cycle should be as short as possible in order to'seoure maximum production of ice. In some instances it is also desired to provide a vibratory or jarring motion, at the point where the tray is returned to its normal position, it being possible by such motion to return the tray to its normal shape.
It is accordingly a specific object to provide for successive slow and rapid motions of the ice tray and of its compact, unlubricated driving system and to limit both motions exactly as to their points of start and finish. Another related object is to provide for controlled, successive slow motions and rapid vibratory motions of the tray.
I have found it possible to achieve these several objects with the aid of a system using a remarkably simple es-' capement. In a preferred form this escapement comprises a rotary driving element and a rotary driven element, one of said elements being rigidly secured to a motor shaft and the other, in slightly eccentric position, to the tray, and both being installed in the refrigerated atmosphere and adapted to operate substantially without libricating oil. The operation of the escapement unit canbriefly be characterized by saying that the driving element imparts a portion of one turn and up to a predetermined point of escapement of the driven element from the driving element, where a resilient element provides for rapid return of the tray to the normal or zero position, advantageously with vibration of the tray, while the slow motion of the driving element continues, effecting a refill control action and ultimately resetting the driving element at the zero point. These and related features will best be explained in the following description of an embodiment of the invention.
In the attached drawing FIGURE 1 is a perspective view of an ice maker incorporating the automatic drive and escapement mechanism of this invention. FIGURE 2 is a fragmentary, sectional view, taken generally along line 2-2 in FIGURE 1 and indicating different positions and motions of driving and driven elements of the escapement device. FIGURE 3 is a schematic representation of electrical circuits desirably used in the operation of' by well known refrigerating apparatus, not shown. Thereafter the tray, with the ice frozen therein 'and adhering to the walls of the tray, is overturned by means comprising output shaft 11 of motor M and escapement mechanism 12 driven by said shaft. This mechanism is provided in accordance with the invention in order to obtain a reversible two-speed rotation of the tray from the unidirectional single-speed rotation of the motor shaft.
Said unidirectional rotation is indicated by an arrow R which is directed counterclockwise as seen in FIGURE 2. This rotation of the motor shaft is initially applied by the escapement mechanism to one end'of the tray, whereby it overturns the tray, engages the opposite end of the tray with a stop device 13, FIGURE 1, and then causes the rotation of the driven end of the tray to continue,
' thereby flexing and twisting the tray and causing the ice to break loose and to slide out of the overturned and flexed tray.
When this has been done, the escapement mechanism disconnects the tray from the motor shaft, as will be described presently. At this point it is to be noted that a spring 14 then returns the disconnected tray to a stop device 15, advantageously in a rapid snap action or vibratory impact, thereby returning the tray to its normal filling and freezing position and to its normal unfiexed form and making it possible to begin proper refilling of the tray at once upon the harvesting of the ice. Meanwhile the motor shaft continues its unidirectional, relative slow rotation, incident to which it controls the required opening and closing of automatic fill valves for the ice tray and, as a final phase of each operating cycle, elfects resetting of the drive shaft in zero position, as will be described hereinafter.
The preferred form of the escapement, provided in accordance with the invention and best shown in FIGURES 2 and 4, includes a rigid finger 16 radially extending from motor shaft 11, with a rigid finger tip 17 constructed and arranged in form of a small plate member secured to the free end of the finger and lying in a plane radial of shaft 11. Similarly a finger tip 18 is provided on a finger 19,
the latter finger tip lying in a plane radial to a shaft 20 The so arranged finger tips 17, 18 can easily be adjusted so as to be in engagement one with the other over a predetermined, angular part of a complete rotation of the tray-supporting shaft 20, and only over such part (FIGURE 2). For this purpose the center of tray shaft 20 lies on a small circle C about the center of motor shaft 11, at a point more than 90 degrees from the normal or zero point of both fingers, to insure overturning of the tray. The center of shaft 20 also lies substantially less than 360 degrees from said point (always in the direction of motor rotation R), to provide for valve control action as will be described hereinafter.
Accordingly, when the directly driven end of the tray reaches a point 24 of said rotation R (FIGURE 1), such as to obtain the desired degree of flexing beyond stop 13, the relative positions of the two fingers, FIGURE 2, are such that the engagement of the two finger tips is lost, as is shown in this latter figure in full lines.
Thereupon the tray finger tip 18 is free to escape from its former engagement with the motor-driven finger tip 17, the tray finger 19 being urged to such escape by the spring force S supplied by spring 14. The spring-actuated finger 19 and the tray then return to their normal position by rapid, snap acting return rotation, thereby bringing one edge portion of the tray into contact with stop 15 (FIGURE 1) and thus causing vibration or jarring I of the tray, (FIGURE 2), as more fully described in said Courson application. Meanwhile the motor shaft 11 and motor finger 16 continue their relatively slow rotation R.
The complete operation of the new ice maker mechanism can now be described as follows:
Subfreezing temperatures are maintained around the ice maker but during the freezing of water in tray the temperature of the tray substantially remains at the freezing point of water. A similar temperature then exists in a bellows 25, FIGURE 3, which senses the temperature of the tray by a suitable contacting mechanism 26, FIGURE 1, more fully described in said Courson application. When the freezing of ice has been completed, the temperature falls to a lower level in the tray, and correspondingly in bellows 25, causing contraction of this bellows and closing of a switch 27, FIGURE 3. This now starts motor M, thereby slowly rotating the motor shaft 11 and motor finger 16. The slow, unidirectional rotation of this finger forcibly turns finger 19 and twists the ice-filled tray, causing the ice to break loose and slide out of the tray, as already described. This is followed by the escapement action which has also been mentioned.
In this escapement action spring 14, FIGURE 1, effects rapid, clockwise return rotation and unflexing of the now empty tray. For this purpose the spring, which desirably surrounds tray shaft 20, has one end 28 secured to a stationary bracket 29 on support structure 23, while having its other end 30 engaging a bracket 31 secured to one end of the tray. (It may be noted that a generally similar bracket 32 is provided adjacent the stationary end 28 of the spring; this other bracket is loose on tray shaft 20 and serves only as a guiding element.) The springengaged bracket 31 is fast not only on the tray but also on said shaft and thereby rigid with tray finger 19, the fastening of the tray shaft to this spring-engaged bracket being effected by a pin 33. The tray is secured to the two brackets by fasteners 34. By means of these simple arrangements it is possible for the unidirectionally rotating motor finger to turn a first or power end of the tray, including bracket 31, to gradually and forcibly flex the tray counterclockwise (R), and wind up the spring (see part F of arrow R in FIGURE 2, which suggests the gradual increase ofthe spring force) until the predetermined position 24 is reached, Whereafter the spring can move the tray and tray finger rapidly and clockwise (S).
During and after the split second return motion of the tray the relatively slower unidirectional rotation R of 4: motor shaft 11 is continued by motor M and it will now be noted that said shaft operates control means, shown in FIGURE 3 as a pair of earns 35, 36. At any suitable point 42" of rotation R of the motor shaft (FIGURE 2), corresponding to some suitable time after the start of such rotation, the first cam 35 by means of follower 37 (FIG- URE 3) closes a switch 38 which from then on keeps motor M energized regardless of the position of thermostatic switch 27. (This latter switch then opens, as the aforementioned follower 37 closes a further switch 39 energizing a small heater 40 which returns thermostat bellows 25 to the normal expanded position thereof.)
In due course thereafter, the continuing unidirectional rotation of motor shaft 11, at point 42" (FIGURE 2), establishes a position wherein the second cam 36 (FIG- URE 3) closes a switch 41, opening a valve V in a tray refilling system 42. The valve opening operation 42' (FIGURE 2) is now caused by this latter timing cam to take place, during a portion of the motor cycle in which the escapement of finger 19 from finger 16 has taken place, so that the tray by then has safely returned to its normal position for filling.
Water now enters one of the series of tray compartments 51 to 57 (FIGURE 1), overflowing by way of suitable notches 58 in the partitions 59 dividing these compartments. Ultimately (FIGURE 3) the motor shaft 11 turns cam 36 to a position wherein filling switch 41 opens and fill valve V closes, and shortly thereafter the other cam 35 by follower 37 reopens switches 38, 39, thereby replacing the control structure in its original position so long as thermostatic switch 27 remains open.
It will now be appreciated that the new drive and escapement, characterized by the two simple fingers 16, 19, causes the tray to be moved slowly and forcefully in counterclockwise direction R, F for overturning, twisting, and harvesting, whereafter it causes the tray rapidly-resiliently to return to its normal position while one of the fingers continues to complete a slow rotation for purposes of fill-valve control and resetting. It will also be seen that the start and end points of these slow and fast motions can readily be controlled in a precise way, that nevertheless no complex, lubricated device is required, and that the mechanism can readily operate at a subfreezing temperature.
While only one embodiment of the invention has been described, it should be understood that the details thereof are not to be construed as limitative of the invention, except insofar as is consistent with the scope of the following claim.
Escapement apparatus for controlling an ice maker of the type wherein a flexible ice tray is subjected to consecutive filling, overturning, flexing, unfiexing, and returning operations, comprising:
an approximately horizontal tray shaft for the support of said tray, subject to pivoting motions throughout said operations;
a motor shaft having an end portion opposite an end portion of said tray shaft and generally aligned therewith but slightly eccentric thereof;
a pair of finger means, one secured to each of said end portions, said finger means extending approximately radially of said respective shafts, one generally opposite the other, and being capable of engagement one with the other throughout a major portion of said operations and, by means including the eccentricity of the shafts, capable of escapement from one another during the remaining portion of said operations; and
means for driving said motor shaft uni-directionally through a single rotation for thereby initially providing said engagement between said finger means to overturn the ice tray and then to flex it, and for then providing said escapement to allow the returning operation of th ice tray while also allowing continuation and ultimate completion of said single rotation of the motor shaft.
References Cited by the Examiner UNITED STATES PATENTS 8/1956 Sampson 62267 Galin 623'70 Schweller Q. 62369 Galin 62370 Nelson 62370 ROBERT A. OLEARY, Primary Examiner.
EDWARD J. MICHAEL, Examiner.
G. A. EPPNER, Assistant Examiner;