US3375678A

US3375678A - Hydraulic icemaker

Info

Publication number: US3375678A
Application number: US576907A
Authority: US
Inventors: Dwight W Jacobus; John E Sterling; Donald G Mcdowell
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1966-09-02
Filing date: 1966-09-02
Publication date: 1968-04-02
Anticipated expiration: 1985-04-02

Description

April 1968 D. w. JACOBUS ETAL 3,375,678

HYDRAULI C I CEMAKER Filed Sept. 2, 1966 INVENTORS DWIGHT W. J'ACOBUS JOHN E. STERL\NG BY DC NALD e. McDOWELL my M THEIR AT ORNEZY United States Patent 3,375,678 HYDRAULIC ICEMAKER Dwight W. Jacobus and John E. Sterling, Louisville, Ky., and Donald G. McDowell, New Albany, Iud., assignors to General Electric Company, a corporation of New York Filed Sept. 2, 1966, Ser. No. 576,907 4 Claims. (Cl. 62353) ABSTRACT OF THE DISCLOSURE The present invention relates to an automatic icemaker and is more particularly concerned with a hydraulic icemaker for operation in the freezer compartment of a household refrigerator.

Automatic icemakers for household refrigerators normally comprise means for sequentially and automatically filling one or more mold cavities with Water, freezing the water to form ice pieces and discharging the formed pieces into a suitable container. An icemaker of this type comprising a hydraulically operated piston for removing ice pieces from the mold and automatically supplying a new charge of water to the mold is described and claimed in copending patent application Ser. No. 512,723, filed Dec. 9, 1965 in the names of Dwight W. Jacobus and William C, Bodong and assigned to the same assignee as the present invention. It comprises a mold having at least one ice cavity and an ice ejecting means comprising a cylinder and piston assembly and an ejector arm positioned within the cavity and movable by the piston to a raised position to eject an ice piece from the cavity. The cylinder and piston are cooled to below freezing temperatures during formation of ice in the mold whereby during this freezing step, iceformed from residual water present in the cylinder freezes the piston in a lower or normal position against movement within the cylinder. After formation of ice in the mold cavity, the ice bond between the piston and cylinder walls is thawed by energization of suitable cylinder heating means and a volume of water introduced under pressure into the lower part of the cylinder moves the piston to an upper position in which ice is ejected from the top of the mold cavity. As the piston approaches its upper position, a pivoted sweep actuated by the hydraulically operated piston sweeps the ice from the ejector arm into a storage receptacle.

Under some operating conditions of the abovedescribed icemaker, it has been found that the hydraulic pressure for operating the piston and sweep was insufficient to break the ice bond between the ejector arm and ice piece with the result that the icemaker stalled or the ice pieces remained on the surface of the mold.

It is an object of the present invention to provide a hydraulic icemaker of the above-described type including improved means for positively'sweeping an ejected ice piece from the mold.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part-of this specification.

In accordance with the present invention, there is provided an improved hydraulic icemaker of the type described in the aforesaid Jacobus et al. patent application including means for separating an ejected ice piece from the mold structure comprising a pivoted impactor and energy storing means in the form of a spring biasing the impactor to a position overlying the top of the mold cavity and means operable by the piston during ejection movement thereof for moving the impactor to a position in which energy is stored in the spring and thereafter releasing that energy for contact of the impactor with the ice piece.

For a better understanding of the invention reference may be had to the accompanying drawing in which:

FIGURE 1 is an elevational view, partly in section, of the icemaker structure of the present invention;

FIGURE 2 is a vertical sectional view taken generally along line 22 of FIGURE 1 illustrating the positions of certain components of the icemaker prior to the hatvesting operation thereof; and

FIGURE 3 is a sectional view similar to FIGURE 2 illustrating the positions of the same elements in one stage of the harvesting operation.

Referring particularly to FIGURES 1 and 2 of the drawing, the automatic icemaker of the present invention includes a metal mold block I mounted on a frame 2 which in turn is adapted to be secured to the wall of a freezer compartment by means of brackets 4.

The mold block includes a plurality of ice cavities 7. These ice cavities 7 are shown as being arranged in groups of threes on opposite sides of a cylinder 8. The cavities 7 are separated from one another or from the upper portion of cylinder 8 by walls 11, Each of these walls includes a vertical passage 14 which provides means for the flow of water from the cylinder 8 into the various ice cavities 7.

The cylinder 8 and a piston 16 contained within the cylinder provides hydraulic power means for ejecting the ice pieces from the cavities 7. During formation of ice pieces in the mold cavities, the piston 16, as is shown in FIGURE 2 of the drawing, is in its normal position with the bottom end 18 thereof adjacent to but spaced from the bottom wall 19 of the cylinder. An extended or upper portion '20 of the piston is normally disposed in the upper portion of the cylinder 8. Secured thereto, or forming an integral part thereof, are ejecting pad structures 22. Each of these pad constructions 22 comprises a tapered vertical member 23 normally contained in the slots or passages 14 in the wall dividing the upper portion of the cylinder from the adjacent cavities 7 and a horizontal arm 24 extending through the cavities 7 or more specifically through the remaining passages 14 and having thereon pads 25 respectively positioned in the bottom of each of the cavities 7 during formation of the ice pieces.

The piston 16 is biased to its lower position within the cylinder 8 by means of a yoke 27 of inverted U-s'hape extending across the top surface of the upper portion 20 of the piston and biased downwardly by tension springs 28 connecting the yoke 27 t0 anchors 29 on a lower part of the icemaker frame 2.

The icemaker also includes a mold cavity heater 31 positioned adjacent the lower perimeters of the cavities 7 and a cylinder heater 32 in heating relationship with the lower portion of the cylinder 8.

As is more fully described in the aforementioned Jacobus et a1. application, a measured volume of water under pressure is employed for operating the piston 16 to eject ice pieces from the mold and this same volume of water is then transferred to the mold cavities. This water is supplied to the mold structure through supply line 33 connecting the bottom wall 19 of the cylinder 8 with a measuring vessel (not shown) positioned outside the freezer compartment in an above freezing ambient and connected to a high pressure water source such as va city water supply.

Means for conveying the measured volume of water from the cylinder 8 to the cavities 7 following an ejection cycle comprises a T-shaped passage 34 within the piston 16. This passage includes a vertical inlet portion 35 and a pair of outlets 36 in the vertical side walls of the piston 16.

In the automatic operation of the icemaker, when the temperature of the mold decreases to the point indicating that a charge of water previously supplied to the mold cavities 7 as well as water contained in the cylinder and the piston passage 34 has frozen, the cylinder is connected through line 33 to the source of high pressure water and

heaters

31 and 32 are energized.

The piston 16 does not move under this water pressure due to the fact that it is frozen to the inner surface of the cylinder 8 by a film of ice within the clearance space between the walls of the piston and the cylinder and water is prevented from flowing through passage 34 to the cavities 7 by this film of ice as well as a plug of ice formed within passage 34. After the

heaters

31 and 32 have warmed the walls of the cavities 7 and the cylinder 8 to release the ice pieces 38 contained within the cavities 7 and melt the ice bond between the piston and cylinder walls, the thawing of the ice bond between the piston and cylinder walls frees the piston so that the piston and the ejection structure 22 move upwardly to lift the ice pieces out of the cavities 7.

During this upward travel of the piston 16, water is prevented from flowing through the bypass passage 34 by the ice plug formed therein during the ice freezing cycle. Melting of this plug after the piston reaches the top of its stroke and is held there by pressure of the water introduced into the cylinder 8 permits the flow of water through the passage 34 thereby relieving the hydraulic pressure within the cylinder 8 so that the springs 28 return the piston to its lower position adjacent the bottom wall 19 of the cylinder. During this return movement of the piston, most of the remaining water from the measuring vessel flows through the bypass passage 34, upwardly through the clearance space between the piston and cylinder and through the passages 14 into the mold cavities.

As the ejection means 22 is moved to its upper position illustrated in FIGURE 3 of the drawing, the ice pieces 38 remain bonded or frozen to the pads 25 so that means must be provided for breaking this bond and sweeping the ice pieces clear of the mold for discharge into a suitable receptacle after the pads 25 reach their upper position. The means employed for this purpose in the aforementioned Jacobus et a1. application comprises a pivoted sweep arm adapted to be operated directly by the piston and hence by the pressure of the water introduced into the cylinder 8. Because the force available for breaking the bond between the ice pieces and the pads was limited to the available water pressure, under some operating conditions, the ice pieces were not separated from the pads with sufficient force to sweep them off the mold surface.

In accordance with the present invention, means are provided for storing the energy supplied by the hydraulic force during upward movement of the piston so that the stored energy can then be converted into a high inertia impact on the ice piece or pieces for breaking them free of the ejection pad and forcibly sweeping them from the mold. To this end, there is provided an inertial sweep or more specifically, in the illustrated embodiment of the invention, two separate inertial sweeps generally indicated by the numeral 40 on opposite sides of the cylinder 2. Each of these sweeps comprises a relatively heavy mass in the form of a body of metal 41 having secured to the opposite ends thereof the free ends of a pair of

arms

42 and 43 pivotally supported at their lower ends on a shaft 44. The shaft 44 in turn is mounted on the rear surface of the mold 1 as for example on the heat exchange fins 45 provided on the rear vertical surface of the mold 1. The metal mass 41 is biased to a normal position above the cavities 7 as shown in FIGURE 2 of the drawing by means of a helical torsion spring 47 having its coil portion supported on the shaft 44 and its

free ends

48 and 49 respectively engaging the rear side of the metal body 40 and the rear wall of the frame 2.

Impact energy sufiicient to break the ice bond between the ice pieces 38 and the pads 25 is stored in the springs 47 during upward movement of the piston 16 by urging the metal body 40 to its cocked position shown inFIG- URE 3 of the drawing as the piston 16 travels upwardly. For this purpose, the inner arms :42, that is, the arms adjacent the cylinder 8 have secured thereto cams 51 each including an arcuate lower cam surface 52. A generally T-shaped pawl 53 secured to yoke 27 between the arms 42 includes a cross portion 54 the ends of which are adapted respectively to engage the cam surfaces 52 during upward movement of the piston and to cock the inertial sweep 40 to the positionshown in FIGURE 3.

Preferably the pawl 53 is made of polypropylene and includes a hinge portion 56 to permit the ends of the cross portion 54 of the pawl. to pivot about the hinge portion and ride over the sloping top surface 55 of the cam means 51 during downward movement of the yoke 27 following an ice harvesting cycle. A spring 56 overlying the hinge area biases the cross portion forwardly to a position in which the ends thereof would contact the cam surfaces 52 during upward movement of the yoke 27.

The cam member 51 is so constructed that as the piston approaches the top of its stroke where the ice pieces have been lifted out of the cavities 7, the impact means 40 has been cocked to the position shown in FIGURE 3 of the drawing. Then, as the cross portion 54 of the pawl passes over the forward edge of the cam member 51, the members 40 are releasedto impact the ice pieces 38 thereby breaking the ice bond and knocking the ice pieces from the top of the mold. As the sweeps are then in the position shown in FIGURE 2 of the drawing, during return movement of the pistonj the ends of the cross member 54 slide over the upper surfaces 55 of the cam means 51 and downwardly along the rear of the surfaces of the cam means and the cross member is returned to its normal position shown in FIGURE. 2 by spring 57.

By the above described construction, energy slowly provided by the hydraulic forces lifting the piston 16 is stored in the spring 47 and is then quickly released at the end of the piston stroke. Since the stored energy is many times that available directly from the hydraulic force,

freeing of the ice pieces from the pads is assured regardless of any variations in the hydraulic pressures within the cylinder 8.

While there has been shown and described a specific embodiment of the present invention it is to be understood that it is not limited thereto and is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the in vention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An automatic icemakercomprising: a freezer mold including a vertical cylinder and at least one cavity for the formation of an ice body therein, a piston in said cylinder movable between a lower position and an upper position in which the. top end of said piston projects above the top end of said cylinder, means for introducing water under pressure into said cylinder to raise said piston to said upper position, an ejecting pad in said cavity and means operatively connecting said pad to said piston for raising said pad and ejecting an ice body carried by and frozen to said pad from the upper end of said cavity upon movement of said piston to its upper portion, means for delivering an impactforce to said ice body to break the said body free from said pad comprising:

a lever means comprising an arm structure pivotably mounted at one end on said mold and having a mass at the free end thereof normally positioned above the upper end of said cavity,

spring means biasing said mass to said normal position,

and operating means operable during movement of said piston to said upper position for storing energy in said spring by moving said mass to a cocked position to one side of said cavity and thereafter releasing said mass for impact contaot with said ice body when said piston is in its upper position.

2. The icemaker of claim 1 in which said operating means comprises a cam surface on said arm structure and a hinged member movable by said piston to engage said cam surface during movement of said piston to its upper posit-ion and urge said means to said cocked position.

'3. The icem'aker of claim 2 in which said hinged member is composed of polypropylene.

4. An automatic icemaker comprising means for freeing an ice body from a mold cavity, hydraulic pressure operated lifting means for lifting said ice body out of said cavity and means for storing energy provided by said hydraulic pressure during lifting of said ice body and releasing the stored energy when said ice body is free from said cavity to impact said ice body and remove it from said lifting means,

said energy storing means comprising a mass pivotally mounted for movement from a normal position above said cavity to a position to one side of said cavity,

and means operable during lifting movement of said lifting means for moving said mass to one side of said cavity and thereafter releasing said mass for impact contact with said ice body when said ice body is free from said cavity.

References Cited UNITED STATES PATENTS 2,757,519 8/1956 Sampson 62353 X 2,969,651 1/1961 Bauerlein 62135 3,163,018 12/1964 Sh aw 62-353 X 3,287,927 11/1966 Jacobus 62-353 X ROBERT A. OLBARY, Primary Examiner. W. E. WAYNER, Assistant Examiner.