US3866434A

US3866434A - Meniscus control insert for automatic ice maker water fill tube

Info

Publication number: US3866434A
Application number: US416189A
Authority: US
Inventors: Cecil C Pugh; Ronald L Ringer
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1973-11-15
Filing date: 1973-11-15
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18

Abstract

A water supply conduit extending through the insulation of a domestic refrigerator back wall with its outlet nozzle positioned above the freezing tray of an automatic ice maker. The conduit has inserted therein a molded plastic insert member forming a watertight seal with the inner surface of the conduit. The insert achieves meniscus control by means of a diverter cone circumscribed by a plurality of radial flow reduced orifices providing positive shut-off of the water remaining in the tube after completion of the ice tray fill cycle. The velocity of the water exiting the conduit outlet nozzle is reduced by baffle means to provide a defined stream of water for filling the tray.

Description

United States Patent Pugh et a1. 1 1 Feb. 18, 1975 [54] MENISCUS CONTROL INSERT FOR 3,775,994 12/1973 Linstromberg et a1. 62/340 UTO ICE MAKER WATER FILL 3,788,089 1/1974 Graves 62/340 TUBE Inventors: Cecil C. Pugh, Dayton; Ronald L.

Ringer, Xenia, both of Ohio General Motors Corporation, Detroit, Mich.

Filed: Nov. 15, 1973 Appl. No.: 416,189

Assignee:

References Cited UNITED STATES PATENTS 12/1947 Caesar 62/345 8/1957 Gaugler ct a1. 62/344 11/1961 Linstromberg et a1 62/340 8/1962 Archer 62/345 Primary Examiner-Kenneth W. Sprague Assistant E.raminerlames C. Yeung Attorney, Agent, or Firm-Edward P. Barthel [57} ABSTRACT A water supply conduit extending through the insulation of a domestic refrigerator back wall with its outlet nozzle positioned above the freezing tray of an automatic ice maker. The conduit has inserted therein a molded plastic insert member forming a watertight seal with the inner surface of the conduit. The insert achieves meniscus control by means of a diverter cone circumscribed by a plurality of radial flow reduced orifices providing positive shut-off of the water remaining in the tube after completion of the ice tray fill cycle. The velocity of the water exiting the conduit outlet nozzle is reduced by baffle means to provide a defined stream of water for filling the tray.

3 Claims, 5 Drawing Figures PATENTED FEBI 8 I975 MENISCUS CONTROL INSERT FOR AUTOMATIC ICE MAKER WATER FILL TUBE This invention relates to water conduit feed lines for automatic ice makers and more particularly to an insert for a water line fill tube for improved filling of the freezing tray of an automatic ice maker.

As discussed in co-pending U.S. Patent application Ser. No. 398,932 now U.S. Pat. No. 3,835,661, as signed to the same assignee as the instant application, the design of water fill tubes for use with automatic ice makers installed in household refrigerator cabinets ideally requires low water velocity to provide a controlled welLdefined stream of water exiting the nozzle in order to fill the freezing tray of an automatic ice maker. It has been determined that if the water fill tube is horizontally disposed within the top wall of the refrigerator freezer cabinet so as to be in heat conducting relation with the ambient exposed outer shell of the cabinet the problem of water freezing in the tube is obviated. However, under assembly line conditions it has proved difficult to maintain the horizontal condition of the tube leading to drainage problems within the water fill tube after each water fill cycle of the ice maker. Also upon the refrigerator cabinet being installed in a kitchen the fill tube will, in many cases, be oriented away from the horizontal at varying degrees depending upon the exactness of the leveling operation of the refrigerator cabinet. The result is the meniscus of the water charge within the water fill tube at shut-off will be located at various positions therein depending upon the degree of slope of the water line. Tests have shown that if the meniscus of the water charge is allowed to recede a substantial amount after the fill cycle the residual water in the tube will cause a slow drippage of water at the tube outlet within the freezer compartment, which drippage will build-up into an ice barrier such that the freezing of about ten drops of water will result in complet blockage of the tube exit.

The present invention has as an object the provision of an improved water fill tube in the wall of a domestic refrigerator for assisting in the rapid shut-off of water flowing to the freezer tray of an automatic ice maker by providing a molded insert member to be placed in a conventional fill tube having a plurality of restrictor orifices to control the positioning of the meniscus of the water charge after shut-off obviating the accumulation of ice forming water drops at the tube exit.

Another object of the present invention is to provide a meniscus control molded plastic insert for insertion in a domestic refrigerator automatic ice maker fill tube, the insert being placed within the generally horizontal portion of the fill tube adjacent the downwardly sloped exit spout thereof, and wherein the insert includes a first cylindrical portion provided with a plurality of axially spaced circumferential ribs and a central passage therethrough. A second integral downstream frustoconical spider ribbed portion encloses an upstream directed extruded nylon inner central diverter cone axially spaced from the downstream exit of central passage whereby the diverter cone diverts the exiting stream of water obliquely through a plurality of circumferentially disposed meniscus restrictor orifices defined by the converging spider ribs. A concentric baffle disk molded on the downstream end of the second frustoconical portion provides a velocity reducing zone where there is enough turbulence combined with the angular entry of the water streams to effectively mix the plurality of water streams to reduce their velocity as they leave the fill tube spout to a point sufficient to insure a defined single stream directed to the ice tray.

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 is clearly shown.

In the drawings:

FIG. 1 is an irregular sectional view of the refrigerator embodying the automatic ice maker illustrating one form of the invention;

FIG. 2 is an enlarged fragmentary side elevational view, partly in section, of the ice maker water fill tube;

FIG. 3 is an enlarged horizontal sectional view of the insert restrictor taken on line 3-3 of FIG. 2;

FIG. 4 is a front elevational view of the insert restrictor; and

FIG. 5 is a fragmentary sectional view taken on line 5-5 of FIG. 4.

Referring now to the drawings and more particularly to FIG. 1, there is shown a frost-free type household refrigerator 20 with an upper below freezing compartment 22 closed by insulated door 24 and a lower above freezing compartment 26 closed by lower insulated door, the top edge of which is shown at 28. These compartments are surrounded by insulated cabinet walls, only the top 29 and rear 30 walls of which are shown, and separated by horizontal insulation wall 32 containing an evaporator compartment 34 provided with a finned evaporator 36 having vertical fins extending from the front to the rear of the compartment 34.

The evaporator compartment is provided with an inlet 38 at the front communicating with the front of the below freezing compartment 22 and additional inlets (not shown) communicating with the top of the above freezing compartment 26. At the rear, the compartment 34 connects with a shroud 40 communicating with the entrance to a centrifugal fan 42 which is driven by electric motor 44 housed in the rear wall 30 of the cavity. The cooling arrangement for the compartment may be similar to that shown in U.S. Pat. Nos. 3,359,750 or 3,310,957 which may be referred to for further details of the construction of the refrigerator.

The fan 42 is provided with an upwardly extending discharge duct 46 having a distributor 48 in the top which distributes the discharge of air through the below freezing compartment 22. The evaporator 36 is maintained in a suitable below freezing temperature such as 5 to -l5F. to maintain the compartment 22 at the temperature of 0F. or below.

For providing special cooling for the automatic freezer, the distributor 48 is provided with a laterally extending discharge duct 50 extending along the intersection of the rear 30 and top 29 walls. Behind the automatic ice maker or liquid freezer 52 the lateral extending duct 50 is provided with wide discharge nozzle 54 which discharges the cold air directly onto the top of the liquid freezer 52 and particularly onto the top of the freezing tray or mold 56.

The mold 56 is provided with two rows of pockets 58 containing four compartments in each row. It is to be understood, however, that the particular configuration of the mold pockets is not important to the present in vention and any conventional mold configuration could be used in the automatic ice maker 52. The mold 56 is supplied with the water or any other liquid to be frozen from a pressure water system to a solenoid control valve 62 which controls the flow of water through a filler or water supply conduit or line 64 extending through the insulation of the top wall 29 to position a discharge nozzle or outlet 65 below the inner liner 67 of the below freezing compartment 22 above the front pockets 58 of the mold 56.

The details of the automatic ice maker 52 disclosed in the present invention are shown in US. Pat. No. 3,540,227 issued Nov. 27, 1970, to C. W. Eyman, Jr. et al. and assigned to the same assignee as the present invention and reference is made to that patent for more complete description of the ice maker and its mode of operation.

The water supply conduit or fill tube generally indicated at 64 is preferably formed from a suitable plastic material such as for example extruded nylon, will be described in detail. As best seen in FIG. 1, the inlet portion 66 of the tube is formed in a smooth curve and extends through an opening 70 in the outer metal shell 72 of the rear wall 30. The opening 70 comprises a resilient grommet 74 that is adapted to be fastened therein allowing the rearwardly projecting horizontal leg portion 76 to extend in a sealed manner through the grommet opening positioning the downwardly directed coupling spout 78 exteriorly of the cabinet. A suitable fitting on cold water supply pipe 80 is adapted to engage the coupling spout 78 in liquid-tight relationship. The smooth arcuate portion 66 of the conduit 64 blends into a generally horizontal central tube portion 81 which in the preferred form of the invention is shown nested in the channel portion 82 of the U-shaped insulation block member 83 formed from suitable material such as rigid polyurethane foam.

As seen in FIG. 1, the water supply conduit or fill tube 64 has its discharge nozzle 65 positioned above the tray 56 of the ice maker. The solenoid valve 62 in the water supply line 80 connects the conduit 64 to a suitable source of water, as for example, to the house water supply in such a manner that when the solenoid valve is energized to open the valve, water flows through the supply pipe 80 into the conduit 64 and discharges into the tray 56 via the nozzle 65. Automatic control of the water supply means is obtained by means of control valve circuitry essentially including a switch (not shown) adapted to complete a control circuit for the valve which opens the valve when the tray 56 is in its upright position after the completion of an ice harvest cycle. Details of one such control circuit are dis closed in the above-mentioned Eyman US. Pat. No. 3,540,227.

As best seen in FIG. 2, the water conduit central tube portion 81 leads into a smooth downwardly curved forward downstream portion 92 terminating in the outlet end or nozzle 65, received in angularly positioned bushing 94 of molded plastic insert 96, which insert is adapted to be located in an opening 98 in the inner liner 67 of the top wall 29. It will be noted that the molding insert 96 also includes an angled bushing 102 for receiving the inner end 103 of an electrical conduit 104, formed from a suitable plastic material, positioned substantially parallel with the water supply conduit 64 with its rearward end 106 extending through a second opening in the grommet 74. The electrical conduit 104 provides a passageway for electrical wiring 108 leading to the power and control terminals of the ice maker control panel 110.

Referring now to FIGS. 2-5, an insert restrictor generally indicated at which is the subject of the present application is illustrated. The insert 120 may be made of suitable resilient material such as for example, molded plastic ethylene vinyl acetate. As illustrated the insert 120 is divided into first and second cylindrical portions or

areas

122 and 124. The first area 122 is an elongate cylindrical stem having a series of ribs 126 extending circumferentially around the insert along the length of the stem 122. Each rib is provided with a downstream sloping face 130 and a perpendicular upstream facing face 132. The first sloping face 131 of the lead rib begins at the circumferential line 134 delineating the base of frusto-conical shaped nose member 136 of the insert second portion 124.

The nose member 136 slopes forwardly or downstream from line 134 and terminates with an integral circular disk 138 which extends radially outwardly perpendicular to the common central axis of the insert 120 to a diameter substantially equal'to the smallest diameter of the stem portion 122. The circumferential edge of the disk 138 is formed with a semi-circular radius in longitudinal section to allow the smooth flow of water therearound. The perpendicular face 132 which is perpendicular to the common central axis of the entire insert 120 extends outwardly from the surface of the first cylindrical body 122 until it intersects sloping face 130 to form a sharp rib 126. The adjacent rib then begins with another sloping face which intersects the smallest diameter of the previous perpendicular face at approximately the same diameter as the diameter of the stem. In the illustrated embodiment five ribs are shown in succession, each having the same outer diameter formed by the intersection of the perpendicular face 132 and the sloping face-130 and each having the sloping face 130 extending in the same direction outward and away from the elongate stem portion 122. After the last upstream rib 126 the insert has yet another rearwardly sloping face 142 which at its largest diameter intersects a reverse sloping face 144 to provide a last rib 146 with the face 144 sloping rearwardly to intersect the outer edge of a first central passage 148 ex tending axially through the stem portion 122 of the insert. The purpose of the end rib 146 is to provide a lead-in surface for the insert which allows for ready insertion through the nozzle end 65 of the fill tube.

The insert central water inlet passage 148 extends forwardly to a point substantially in the plane of the perpendicular face 132 of the initial downstream rib 150. The central passage in the preferred form has a diameter of about 0.242 inches while the fill tube has an inner diameter of about 0.410 inches. The central passage 148 leads into a reduced axial bore 152, having a diameter of about 0.171 inches in the disclosed form.

The converging second nose portion of the insert is spider-like in vertical section having four forwardly tapered ribs 162 in a cross or X-shaped grid pattern. The ribs 162 converge in integral fashion at their downstream end with a central cylindrical core member 166 having its upstream end in the shape of an axially disposed diverter cone 168 converging toward and spaced from the exit of bore 152. The bore 152 thus communicates with a plurality of circumferentially spaced restricted orifices which in the disclosed form are four longitudinally extending slot-like orifices 170 equally spaced at 90 angles.

The diverter cone is forwardly or axially spaced from the restrictor bore 152 such that water exiting bore 152 strikes the conical diverter surface at an oblique angle to radially direct the water through the orifices 170. The water flow is thus divided into four jets or streams which are directed in outwardly diverging radial paths from the orifices 170 at an increased velocity from that ofthe stream emerging from the restrictor bore 152. To prevent the jets from producing an undefined turbulent stream exiting the spout 65 because of the increased velocity imparted to the four jets, the baffle disk 138 is employed to intercept portions of the four jets and create sufficient turbulence, combined with the angular reflection of the four jet streams after impinging on the inner surface 172 of the fill tube to effectively mix the four streams of water and reduce their velocity to provide a single defined stream leaving the exit spout 65 and provide a controlled water fill of the tray.

By virtue of providing the plurality of restrictive angular exit openings 170 tests have shown that upon the water tube supplying a predetermined charge of water to the tray, which in the disclosed form requires about 12 seconds, the flow of water through the tube is stopped by activating the solenoid valve 62 and the receding water in the tube forms a reduced meniscus at each of the restrictive angular orifices 170. The result is that the remaining water is held or retained by the plurality of menisci at the insert first portion 124 to obviate water drops exiting the tube exit spout 65 thus preventing the freezing of the drops and eventual blockage of the fill tube.

It will be noted that the water charge retained in the central tube portion 81 is prevented from freezing by virtue of being in good thermal conduction with the outer shell portion 90 of the cabinet by means of an intermediate layer 113 of elastic compound in the same manner as the fill tube disclosed in copending US Ea: tent application Ser. No. 398,932, filed Sept. 20, 1973, now US. Patent 3,835,661.

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

We claim:

1. A supply conduit extending through a wall of a refrigerator cabinet for supplying liquid to a freezing mold of an automatic ice maker, said conduit including an intermediate linear cylindrical portion formed with an inlet end and a downwardly curved outlet end; said conduit intermediate portion having an insert positioned therein to receive all the liquid from said inlet end, said insert comprising an elongate cylindrical stem portion on its upstream end having a central longitudinal axis and an integral frusto-conical shaped nose portion on its downstream end with the nose portion large base coincident with the downstream end of said stem portion, rib means on the outer surface of said stem portion for sealingly engaging the inner surface of said linear portion, said nose portion having an obstruction disk integrally formed on its downstream small base end concentric with said stem portion, said insert stem portion having a central water inlet passage extending therethrough to a point adjacent the downstream end of said stem portion, said central passage connecting with a reduced axial bore extending a predetermined distance into said nose portion, a diverter cone at the downstream end of said bore with its nose pointed in an upstream direction such that said cone is aligned on said central longitudinal axis, said frusto-conical nose portion having a plurality of elongated restricted exit orifices circumferentially spaced therearound defining a plurality of radial ribs therebetween, whereby liquid entering said axial bore is radially diverted by said diverter cone through said restricted exit orifices, the exiting liquid upon contacting said obstruction disk creating a turbulent reduced velocity flow of the liquid prior to exiting from said conduit outlet portion, and whereby upon said conduit supplying a predetermined charge of liquid to the mold the flow of liquid in said conduit is stopped and the meniscus of the liquid remaining in said conduit is retained at said insert restricted exit orifices obviating blockage of said supply conduit by preventing water drops from exiting and freezing at said conduit outlet portion.

2. A supply conduit extending through a wall of a refrigerator cabinet for supplying water to a freezing mold of an automatic ice maker, said conduit including an intermediate linear cylindrical portion formed with an inlet portion and a downwardly curved outlet portion respectively, at each end thereof; said conduit intermediate portion having a plastic insert positioned therein adjacent said downwardly curved outlet portion to receive all the water from said inlet portion, said insert comprising an elongate cylindrical stem portion on its upstream end having a central longitudinal axis and an integral frusto-conical shaped nose portion on its downstream end with the nose portion large base coincident with the downstream end of said stem portion, said stern having a series of ribs extending circumferentially therearound for sealingly engaging the inner surface of said linear portion, said nose portion having an obstruction disk formed on its downstream small base end concentric with said stem portion and having a diameter approximately equal to the diameter of said stem portion, said insert stem having a central water inlet passage extending therethrough to a point adjacent the downstream end of said stem portion, said central passage connecting with a reduced axial bore extending about midway into said nose portion, a diverter cone at the downstream end in said bore with its nose pointed in an upstream direction such that said cone is aligned on said central longitudinal axis, said nose portion having a plurality of elongated restricted exit orifices circumferentially spaced therearound forming a plurality of radial ribs therebetween, whereby water entering said axial bore is radially diverted by said diverter cone through said restricted exit orifices, the exiting water upon contacting said obstruction disk creating a turbulent reduced velocity flow of the water prior to exiting from said conduit downwardly curved outlet portion, and whereby upon said conduit supplying a predetermined charge of water to the mold the flow of water to said conduit is stopped and the meniscus of the water remaining in said conduit is retained at said insert restricted exit orifices obviating blockage of said supply conduit by preventing water drops from exiting and freezing atsatd sens i t qtlstr rtiss-n c 3. A water supply plastic conduit positioned between the inner liner and the outer shell of a refrigerator cabinet insulated top wall for supplying water to a freezing tray of an automatic ice maker, said conduit including an intermediate linear cylindrical portion formed downwardly extending curved inlet and outlet portions respectively, at each end thereof; said linear portion positioned adjacent the refrigerator top wall outer shell so as to receive room heat by conduction and thereby prevent freezing of water therein, said conduit intermediate portion having a plastic insert positioned therein adjacent said downwardly curved outlet portion to receive all the water from said inlet portion, said insert comprising an elongate cylindrical stem portion on its upstream end having a central longitudinal axis and an integral frusto-conical shaped nose portion on its downstream end with the nose portion large base coincident with the downstream end of said stern portion, said stem having a series of ribs extending circumferentially therearound for sealingly engaging the inner surface of said linear portion, said ribs having a sloping face and a perpendicular face, said sloping face extending radially outwardly and away from said nose portion, said perpendicular face extending radially outward perpendicular to the axis of said stem portion and intersecting said sloping face to define a circular edge, said nose portion having an obstruction disk formed on its downstream small base end concentric with said stem portion and having a diameter approximately equal to the diameter of said stem portion, said insert stem hav' ing a central water inlet passage extending therethrough to a point adjacent the downstream end of said stem portion, said central passage connecting with a reduced axial bore extending about midway into said nose portion, a diverter cone at the downstream end in said bore with its nose pointed in an upstream direction such that said cone is aligned on said central longitudinal axis, said nose portion having four elongated restricted exit orifices circumferentially spaced therearound forming four radial ribs therebetween, whereby water entering said axial bore is radially diverted by said diverter cone through said restricted exit orifices, the exiting water upon contacting said obstruction disk creating a turbulent reduced velocity flow of the water prior to exiting from said conduit downwardly curved outlet portion, and whereby upon said conduit supplying a predetermined charge of water to the tray the flow of water to said conduit is stopped and the meniscus of the water remaining in said conduit is retained at said insert four restricted exit orifices obviating blockage of said supply conduit by preventing water drops from exiting and freezing at said conduit outlet

Claims

2. A supply conduit extending through a wall of a refrigerator cabinet for supplying water to a freezing mold of an automatic ice maker, said conduit including an intermediate linear cylindrical portion formed with an inlet portion and a downwardly curveD outlet portion respectively, at each end thereof; said conduit intermediate portion having a plastic insert positioned therein adjacent said downwardly curved outlet portion to receive all the water from said inlet portion, said insert comprising an elongate cylindrical stem portion on its upstream end having a central longitudinal axis and an integral frusto-conical shaped nose portion on its downstream end with the nose portion large base coincident with the downstream end of said stem portion, said stem having a series of ribs extending circumferentially therearound for sealingly engaging the inner surface of said linear portion, said nose portion having an obstruction disk formed on its downstream small base end concentric with said stem portion and having a diameter approximately equal to the diameter of said stem portion, said insert stem having a central water inlet passage extending therethrough to a point adjacent the downstream end of said stem portion, said central passage connecting with a reduced axial bore extending about midway into said nose portion, a diverter cone at the downstream end in said bore with its nose pointed in an upstream direction such that said cone is aligned on said central longitudinal axis, said nose portion having a plurality of elongated restricted exit orifices circumferentially spaced therearound forming a plurality of radial ribs therebetween, whereby water entering said axial bore is radially diverted by said diverter cone through said restricted exit orifices, the exiting water upon contacting said obstruction disk creating a turbulent reduced velocity flow of the water prior to exiting from said conduit downwardly curved outlet portion, and whereby upon said conduit supplying a predetermined charge of water to the mold the flow of water to said conduit is stopped and the meniscus of the water remaining in said conduit is retained at said insert restricted exit orifices obviating blockage of said supply conduit by preventing water drops from exiting and freezing at said conduit outlet portion.

3. A water supply plastic conduit positioned between the inner liner and the outer shell of a refrigerator cabinet insulated top wall for supplying water to a freezing tray of an automatic ice maker, said conduit including an intermediate linear cylindrical portion formed downwardly extending curved inlet and outlet portions respectively, at each end thereof; said linear portion positioned adjacent the refrigerator top wall outer shell so as to receive room heat by conduction and thereby prevent freezing of water therein, said conduit intermediate portion having a plastic insert positioned therein adjacent said downwardly curved outlet portion to receive all the water from said inlet portion, said insert comprising an elongate cylindrical stem portion on its upstream end having a central longitudinal axis and an integral frusto-conical shaped nose portion on its downstream end with the nose portion large base coincident with the downstream end of said stem portion, said stem having a series of ribs extending circumferentially therearound for sealingly engaging the inner surface of said linear portion, said ribs having a sloping face and a perpendicular face, said sloping face extending radially outwardly and away from said nose portion, said perpendicular face extending radially outward perpendicular to the axis of said stem portion and intersecting said sloping face to define a circular edge, said nose portion having an obstruction disk formed on its downstream small base end concentric with said stem portion and having a diameter approximately equal to the diameter of said stem portion, said insert stem having a central water inlet passage extending therethrough to a point adjacent the downstream end of said stem portion, said central passage connecting with a reduced axial bore extending about midway into said nose portion, a diverter cone at the downstream end in said bore with its nose pointed in an upstream direction such that said cone is aligned on said central longitudinal axis, said nose portion having four elongated restricted exit orifices circumferentially spaced therearound forming four radial ribs therebetween, whereby water entering said axial bore is radially diverted by said diverter cone through said restricted exit orifices, the exiting water upon contacting said obstruction disk creating a turbulent reduced velocity flow of the water prior to exiting from said conduit downwardly curved outlet portion, and whereby upon said conduit supplying a predetermined charge of water to the tray the flow of water to said conduit is stopped and the meniscus of the water remaining in said conduit is retained at said insert four restricted exit orifices obviating blockage of said supply conduit by preventing water drops from exiting and freezing at said conduit outlet portion.