Harvesting apparatus for automatic ice maker

Abstract

An improved ice piece harvesting mechanism in which a flexible grid is rotated outwardly from a tray whereby a spring loaded toggle member thereon engages a plurality of stop flanges on a rapper arm for imparting successive impacting forces on the grid by means of the toggle member which engages the progressively canted stop flanges arranged in an arcuate path on the arm. The rapper arm is resiliently biased into contact with the grid allowing the twisting rotational force imparted to the grid to successively overcome the arm bias and impact in turn the upper edge of each of the stop flanges.

Description

This invention relates to an automatic ice maker and more particularly to an improved ice harvesting apparatus for a domestic refrigerator ice maker producing clear ice cubes.

The U.S. Pat. No. 3,775,992, issued Dec. 4, 1973 to J. A. Bright, and assigned to the assignee of the instant application, discloses a clear ice maker having a stationary open top tray containing a predetermined quantity of water. A grid having a plurality of open bottom, open top ice mold cavities is rotatably inserted in the tray such that it displaces substantially all the water into the cavities. The patented ice maker further includes means for heating the side and bottom walls of the tray to keep the water adjacent thereto from freezing while below freezing air is directed over the open top of the tray and grid to freeze water into clear ice cubes starting at the interface between the air and the water in the cavities and continuing downwardly toward the bottom wall of the tray. The present invention concerns an improved ice harvesting mechanism for use with the Bright automatic ice maker which discloses periodically rotating the grid, with its formed ice cubes therein, out of the tray. The mechanism releases the ice cubes into a subjacent storage bucket by means of a rapper arm structure having a plurality of stops arranged on an arcuate path operative for insuring the release of all the cubes from the grid.

Accordingly, it is an object of this invention to provide an improved ice cube release mechanism for use with an ice maker grid having a plurality of ice mold cavities including means for periodically pivoting the grid about one side edge thereof for engagement with spring biased rapper means having a plurality of stop members thereon positioned on an arcuate path for engagement with spring loaded means on one free corner of the grid whereby the stop members are successively engaged to momentarily halt the movement of the grid and then release the grid, causing the inverted grid to impact on the next succeeding stop member insuring the release of all the ice cubes from the grid cavities.

A still further object of the invention is to provide an improved harvesting apparatus for a clear ice maker in a freezer compartment of a domestic refrigerator comprising a tray containing a body of water wherein a plastic grid has a plurality of open bottom, open top ice mold cavities and flexible filler means between the cavities such that upon the grid being pivoted out of the tray and into an initial overcenter position it is engaged by a series of arcuately spaced stop flanges positioned at increasing angles with the horizontal. The flanges are arranged on a spring biased rapper arm while one free corner of the grid is provided with a spring loaded toggle member which successively engages the upper leading edge of each of the stop flanges such that the spring of the rapper arm spring bias is overcome to provide uniform twisting and successive impacts on the tray by the toggle striking each stop flange in turn, and on return rotation of the grid the toggle spring is readily overcome upon contact with the lower trailing edge of the stop flanges.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the Drawings

FIG. 1 is a front elevational view partly in section of the freezer compartment of a domestic refrigerator showing the automatic clear ice maker incorporating the ice release mechanism of the present invention;

FIG. 2 is an enlarged fragmentary elevational view of the ice harvesting release mechanism of FIG. 1, showing the clockwise rotational movement thereof;

FIG. 3 is a view similar to FIG. 2, showing the ice grid being pivoted in its counterclockwise direction for return to the ice maker tray;

FIG. 4 is a blank sectional view taken substantially on the line 4--4 of FIG. 2;

FIG. 5 is an enlarged view of the spring loaded toggle mechanism on the grid;

FIG. 6 is a view partly in section, taken substantially on the line 6--6 of FIG. 5.

Referring now to the drawings and more particularly to FIGS. 1 and 2, there is shown a refrigerator below-freezing compartment 26 located in a frost-free household refrigerator with the compartment 26 closed by an insulated door as shown in the above-mentioned U.S. Pat. No. 3,775,992 to Bright which states that the refrigerator may be of the side-by-side type wherein a right side portion encloses the refrigerated food compartment and a left side portion encloses a lower freezer portion for storing frozen foods and the upper freezer compartment 26 enclosing a clear ice maker shown generally at 28. Fan means blows air through a duct outlet 29 including louvers 30, distributing below-freezing air over the exposed top planar surface of the water in the ice maker.

In general the clear ice maker 28 includes a tray and heater assembly generally indicated at 34, an ice cube grid 36 and an ice storage bucket assembly 38, a weight sensing means 39 for bucket and ice, and an ice harvesting mechanism 40 and a water fill system which is shown in the mentioned Bright patent.

The tray and heater assembly 34 is supported by bracket means 46 from a side wall 48 of the freezer compartment 26. The assembly includes a drawn sheet metal housing 50 forming on one side thereof the water containing tray 52 having a side wall 54 and a bottom wall 56, and on the other side thereof the cavity filled with Freon-filled urethane foam insulation 58. Heater means (not shown) surround the tray 52 and are adapted for heating all four sides 54 of the tray and thereby normally exposes the bottom side of the tray (beneath the ice) to an above-freezing temperature. This retains the bottom portion of the water along the bottom side of the tray in liquid state.

The ice cube grid 36 has characteristics of poor heat conduction and good flexibility at low temperature with good ice release and return memory. As stated in the mentioned Bright patent, the grid preferably comprises a polypropylene housing 140 defining cavities 142 for a plurality of ice cubes with upstanding front and rear thickened end wall portions 141 encasing transverse metal stiffener bars or beams 143, the free ends of which are exposed for mounting the tray in a manner to be described. Each cavity 142 has an inverted truncated pyramidal shape. On the outside of the housing between the cavity forming portions thereof, a flexible filler 146 of RTV silicone rubber fills the space between the cube forming cavities on the outside of the grid 36. The filler material should have an anti-stick characteristic to aid in the release of the grid from the tray during ice harvesting. It should be sufficiently flexible to distribute forces throughout the grid when the grid is rapped for harvesting cubes, while providing increased weight to jar the cubes loose during the multiple rapping of the grid during the ice harvesting cycle. Aside from these characteristics, the filler 146 serves to force water in the tray upward into the cube forming cavities of the grid. Thus, with the grid in place in the tray (FIG. 1, solid line) water level A will become water level B. It should be noted that the water level A will be raised to the water level B when the grid is in the tray. The grid is constructed in a manner to displace substantially all water from the tray into the grid cavities for making clear ice.

As seen in FIG. 1, the ice storage bin assembly 38 includes an ice container 150 of high impact polystyrene which rests on a steel wire shelf 152. The shelf pivots about a support foot 154 on the bottom wall 156 of the freezer portion 26 and includes an upright bracket 158 at the rear thereof which hangs from the weight-sensing means 39 in a manner to keep the back of the shelf spaced from the freezer wall 49. The ice container or bin 150 is built up with a high wall 170 to catch the cubes falling from the grid 36 above. In general, the weight-sensing means 39 will in one mode reflect the presence of ice container 150 on shelf 152, and in another mode, the presence of a full load of ice cubes within the container 150.

The improved harvesting mechanism which is the subject matter of the present invention, will now be described in detail. As seen in FIGS. 1 and 2, the harvesting mechanism is composed of a box-like casing 210 defining a compartment for the grid pivoting and twisting gears which are shown and described in the Bright patent as cam and crank gear rotatably mounted in the casing and driven from the other side by a pair of worm gears which are in turn driven by a motor assembly.

As seen in FIGS. 1 and 2, the harvesting mechanism includes an ice tray impact or rapper arm generally indicated at 211 pivotably supported at its lowermost point from the gusset plate extension 212 of the front plate 50 by suitable means such as pivot pin 213 located adjacent the right-hand vertical edge 214 of the plate 50. It will be noted in FIG. 1 that the longitudinal axis of the pivot pin 213 shown in FIG. 4 as a threaded bolt secured by nut 215, is located in substantially the same horizontal plane as the pivotal axis of the grid 36. The plate 50 has an upstanding hinge ear 216 for receiving and journaling a stud 218 projecting through one end of the metallic grid bar 143. A corresponding coaxial stud at the opposite end of the grid (not shown) fits in suitable socket means of a grid drive gear shown in the above-mentioned Bright patent. The grid drive gear causes the grid 36 to be rotated on the axis of studs 218 from its installed horizontal upright position indicated by letter U, through a vertical position V to its successive ice harvesting positions W, X, Y and Z (FIG. 2) in which the grid will engage a plurality of arcuately spaced grid interrupting members in the form of arresting rectangular flanges located on the impact arm 211 which, in the disclosed form, are three in number indicated by the letters A, B and C operative to engage and momentarily halt the pivoting motion of the grid at its outer free end in a manner to be described.

As seen in FIGS. 1 and 2, the upstanding plate 212 has its upper edge 232 formed with a V notch portion including a downwardly and inwardly canted first edge 234 terminating in a radiused out portion 236 at the intersection with a second downwardly and inwardly canted lefthand portion of the V defined by a rearwardly projecting flange 238 which extends normal to the inner face of the upstanding gusset plate 212 to provide a limiting biasing flange for the counterclockwise pivotal movement of the arm 211 to an included angle of about 50.degree. with the horizontal.

To resiliently bias the impact rapper arm arresting flanges A, B and C in releasable contact with the grid, resilient biasing means are provided which, in the disclosed form, is an impact tension spring 240 comprising a helical closed coil portion 242 having its end coils formed integrally with elongated wire extensions 244 and 246 each of which extensions has a hooked end portion such that the one hooked end engages a hole in the hinge ear 220 while the extension hook 246 engages one of a plurality of adjustment holes 248 in the impact arm 211.

As viewed in FIGS. 5 and 6, the resiliently biased grid striker means is located on the free forward corner of the grid which in the disclosed embodiment is a spring loaded L-shaped toggle member 250 including a radial disposed toggle striker bar portion 252 with the toggle member pivoted on a pivot pin in the form of a threaded bolt 254 extending through a hole in the outer free end of the grid forward stiffener or structural beam 143. A helical coiled torsion spring 256 is telescoped over the bolt 254 and secured by nuts 258 such that one tangential extension 259 of the spring engages toggle foot 260 while the opposite tangential end 262 of the spring engages the upper edge of the grid end wall 141. The foot 260 of the toggle arm engages the edge 264 of beam 143 to prevent counterclockwise rotation of the toggle 150 from its radial biased position as viewed in FIG. 5 upon its engaging the top edges of arresting flanges A-C while allowing resilient clockwise pivotal movement of the toggle arm upon edge 265 of bar 252 contacting the bottom edges 266, 267 and 268 of the flanges A-C during the counterclockwise return movement of the grid as seen in FIG. 3 wherein the toggle arm 250 is shown being rotated past flange C is in contact with lower edge 266 of flange C.

Thus, as the grid 36 is rotated in a clockwise manner from its upright ice tray installed position U through its vertical position V through an angle of about 110.degree. to its first stop flange engaging position W where the toggle bar 252 contacts the upper edge 271 of first arresting flange A so as to momentarily interrupt the pivotal movement of the grid and impart an initial twisting force on the grid 36. Continued torque is applied to the grid by the drive motor means whereby the resilient bias on the rapper arm 211 exerted by tension spring 240 is overcome causing the toggle bar 252 to pivot the arm 211 in a clockwise direction to its dashed line position enabling the toggle bar 252 to snap past the leading edge 271 of flange A whereby the rapper arm will be returned to its solid line position engaging biasing flange 238. The grid is free to rotate about pivot stud 218 to position X in FIG. 2 at an angle of about 125.degree. where the toggle bar 252 will impact on the leading edge 272 of arresting flange B causing the loosened ice cubes to be jarred and released from the grid for free fall into the subjacent bin 38.

Continued torque applied by the drive motor will start a second stage harvest initially twisting the grid until the tension of spring 240 is overcome, allowing the toggle bar to snap past the leading edge 272 of arresting flange B whereby the rapper arm 211 is again returned to its biased stop position resulting in the grid toggle bar impacting on the top leading edge 273 of flange C for a third stage grid harvest at position Y at an angle of about 140.degree.. The process is repeated for a fourth stage harvest by impacting the grid toggle bar 252 on the upper face 274 of the final stop flange D, indicated in solid lines in FIG. 2, wherein the grid has been rotated through an angle of about 160.degree.. The stop flange D halts the pivoting motion of the grid at its outer toggle bar end while the harvesting mechanism disclosed in the mentioned Bright patent continues to drive the grid causing the end nearest the driving mechanism to continue rotation to warp the grid in a manner to insure the release of any remaining ice cubes from the grid. The released cubes fall into the ice container 38 therebelow.

It will be noted that the faces of the arresting flanges A, B and C are each inclined at ever decreasing angles to the vertical. In the disclosed form the angular increments are about 10.degree. with the flange A positioned at about a 40.degree. angle to the vertical, flange B positioned at an angle of about 30.degree. and the flange C at an angle of about 20.degree. to the vertical. The effect of decreasing the flange angles is to maintain a substantially constant angle of incidence between the leading edge 276 of the toggle bar and the face angle of the flanges to insure that approximately the same amount of torque is applied to the grid at each arresting flange prior to the grid snapping past its top edge to impact on the next succeeding flange. Also, the stop flange D has its surface 274 positioned at an angle of about 160.degree. to conform with the final grid angle of about 160.degree..

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

Claims

I claim:

1. An automatic ice maker comprising a warpable grid in a tray adapted to contain water, refrigerating means for the freezing of ice in said grid, drive means for periodically pivoting the grid about one end corner thereof and the adjacent corner of said tray for removing the grid and ice cubes from said tray, a rapper assembly including rapper support means extending from said tray pivoted end, a rapper arm having one end pivotally supported on said rapper support means, resilient means biasing said rapper arm to a first position contacting stop means, said rapper arm having a plurality of longitudinally extending members thereon arranged along an arcuate path centered on said grid pivotal axis, a striker bar pivotally mounted on said grid extending radially outwardly from the free end of the grid front wall and resiliently biased for pivotal movement in one direction only, whereby upon said grid being rotated from a horizontal position in said tray to an overcenter position said bar engages the first one of the arm members momentarily halting the pivoting of said grid, said drive means continuing to power said grid imparting a warping force thereto prior to said bar overcoming said arm resilient biasing means pivoting said arm away from said stop means and permitting said bar to snap past the first arm member and impact on the next succeeding arm member to release ice cubes from said grid, and so forth insuring the release of all the ice cubes therefrom, said drive means being operative to cause reverse rotation of said harvested grid whereby said resiliently biased bar engages said arm members resulting in the bar pivoting in said one direction allowing said grid to be freely returned to said tray.

2. An automatic ice maker comprising a warpable grid in a tray adapted to contain water, refrigerating means for the freezing of ice in said grid, drive means for periodically pivoting the grid about one side thereof and the adjacent side of said tray for removing the grid and ice cubes from said tray, a rapper assembly including rapper support means extending from said tray pivoted end, said rapper assembly having a rapper arm with one end pivotally supported on said rapper support means for movement about an axis parallel to the pivotal axis of said grid, resilient means biasing said rapper arm to a first position contacting stop means, said rapper arm having a plurality of rearwardly extending flanges thereon with the leading edges thereof arranged along an arcuate path centered on said grid pivotal axis, the flanges being oriented with their faces inclined at progressively decreasing angles to the vertical as they approach the rapper pivotal axis, a resiliently biased striker bar pivotally mounted on said grid extending radially outwardly from the free end of the grid front wall for pivotal movement in one direction only, whereby upon said grid being pivoted from its horizontal position in said tray to an overcenter angled position said bar engages the leading edge of the first flange which momentarily halts the pivoting motion of said grid, said drive means continuing to power the grid imparting a warping force thereto prior to overcoming said rapper arm resilient means and thereby pivoting said rapper arm away from said stop means to permit said bar to snap past the first flange leading edge and contact the leading edge of the next succeeding flange to release ice cubes from said grid, and so forth whereby said grid striker bar engages each succeeding flange upper edge causing a plurality of impacts to said grid and thereby insuring the release of all the ice cubes therefrom, the progressively decreasing angles of the flanges being operative to maintain a substantially uniform angle of incidence between each flange leading edge and said striker bar whereby approximately the same amount of warp is applied to said grid as it contacts each successive flange, said drive means being operative to cause reverse rotation of said grid whereby said striker bar engages the lower edges of the flanges resulting in the resiliently biased bar pivoting in said one direction allowing said grid to be freely returned to its upright position in said tray for another ice cube making cycle of said ice maker.