Non-heated ice harvesting

Abstract

An ice-forming stack for an ice-making system, comprising: an ice-making portion (112) comprising an evaporator (116) having a forward face (114); an elastomeric pad (120) disposed over the forward face; a thin planar sheet (130) disposed over a forward surface of the elastomeric pad; and a polymeric film (140) disposed over a forward surface of the sheet, wherein a forward surface of the polymeric film defines an ice-forming surface (144) for forming an ice block thereon, wherein the ice-forming surface comprises one or more openings (143) configured to release pressurized fluid between the ice-forming surface and the ice block formed thereon.

Description

NON-HEATED ICE HARVESTINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Application Ser. No. 63 / 467,702, filed May 19, 2023, entitled “NON-HEATED ICE HARVESTING,” the contents of which are hereby incorporated herein in their entirety by reference.FIELD OF THE INVENTION

[0002] The invention relates to the field of ice-making machines and, more particularly, but not exclusively, to dry harvesting ice-making machines.BACKGROUND

[0003] Automatic ice cube machines are operated, among other places, in industrial ice-making facilities, to supply ice to restaurants, bars, hotels, event venues, supermarket chains, and the like. These machines typically form ice cubes by freezing a flowing stream of water on a chilled evaporator plate.

[0004] It is often desirable to produce ice cubes which bear a graphic design, an image, a logo, a writing, or another visible pattern. Such designs may be created by freezing the ice over an evaporator plate comprising a raised or recessed design, which is transferred to the surface of the ice during the forming process.

[0005] After one or more ice blocks has been formed to a desired thickness, an ice harvesting process takes place, wherein the evaporator is heated to melt a layer of ice in direct contact with the evaporator surface. This causes the release of the bond between the ice one or more blocks and the evaporator, and allow the one or more ice blocks to be harvested.

[0006] Heating of the evaporator is typically accomplished using a defrost cycle, whereby hot fluid is circulated to heat the evaporator. Because the ice will not release and drop off until all of its surface in contact with the evaporator surface has melted, a considerable amount of heat must be applied to the evaporator tubes. A considerable amount of the ice will typically melt away in the time required for the complete release of the formed ice. In the case of ice imprinted with a design, this process can thussignificantly degrade or even completely remove the imprinted surface which is in direct contact with the evaporator.

[0007] Moreover, during the harvesting, a considerable amount of electrical energy is consumed in melting ice previously made. Thus, the typical defrost cycle adversely affects the capacity and energy efficiency of the ice machine, by requiring the machine to perform defrost cycles in which ice production is halted, by melting and potentially deforming the produced ice, and by requiring additional energy to perform the defrost process.

[0008] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the figures.SUMMARY

[0009] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope.

[0010] There is provided, in an embodiment, an ice-forming stack for an ice-making system, comprising: an ice-making portion comprising an evaporator having a forward face; an elastomeric pad disposed over the forward face; a thin planar sheet disposed over a forward surface of the elastomeric pad; and a polymeric film disposed over a forward surface of the sheet, wherein a forward surface of the polymeric film defines an ice-forming surface for forming an ice block thereon, wherein the ice-forming surface comprises one or more openings configured to release pressurized fluid between the ice-forming surface and the ice block formed thereon.

[0011] In some embodiments, the pressurized fluid applies a compressive force which causes a plurality of regions of the ice-forming surface and the sheet to deflect in a rearward direction against the elastomeric pad, thereby breaking a bond and separating between the ice-forming surface and the ice block formed thereon.

[0012] In some embodiments, the sheet comprises one or more slots spaced apart about a surface thereof, wherein each of the slots defines a thin elongated cut in thesurface of the sheet, wherein the slots are configured to facilitate the deflection of the sheet and the ice-forming surface.

[0013] In some embodiments, the elastomeric pad is configured to locally resiliently reduce in thickness in response to the deflection in the region by the ice-forming surface and the sheet.

[0014] In some embodiments, the forward face of the evaporator comprises one or more channels, each defining a groove having a rectangular, semicircular, or V-shaped ross-sectional shape, wherein the reduction in thickness comprises at least partially a displacement of portions of the elastomeric pad into the channels.

[0015] In some embodiments, the elastomeric pad is formed of a thermally- conductive material having thermal conductivity in the range of 15-50 W / m-k, a thickness of between 0.5-3 mm, and a hardness of between 10-50 on the Shore E- hardness scale.

[0016] In some embodiments, the elastomeric pad is configured to removably adhere to the forward face using a thermal compound.

[0017] In some embodiments, the sheet comprises a flexible planar stainless steel sheet having a substantially uniform thickness of between 20-60 pm, and a smooth, polished, or mirror finish over the forward surface thereof.

[0018] In some embodiments, the sheet is configured to removably adhere to the forward surface of the elastomeric pad using a thermal compound.

[0019] In some embodiments, the polymeric film is made of a food- safe material, has a thickness of between 10-60 pm, and a hardness of between 10-40 on the Shore A- hardness scale.

[0020] In some embodiments, the polymeric film is configured to removably selfadhere to the forward surface of the sheet.

[0021] In some embodiments, the forward surface of the polymeric film comprises one or more relief regions adapted to impress or emboss a design onto the ice block formed thereon, wherein each of the one or more relief regions comprises a set of projections extending from the forward surface.

[0022] In some embodiments, the ice-making system further comprises: (i) a control unit; (ii) a refrigeration unit configured to chill the ice-making portion; (iii) a fluidcompressor configured to supply the pressurized fluid; and (iv) a water pumping unit configured to circulate water over the ice-forming surface, thereby forming the ice block thereon.

[0023] In some embodiments, the ice-making system further comprises an iceharvesting stack, comprising: (i) a frame disposed such that a perimeter rearward face thereof is in opposed facing relation with the ice-forming surface, wherein the frame is movable axially in the forward and rearward directions relative to the ice-forming surface; and (ii) an inflatable peripheral seal disposed between the rearward face of the frame and the ice-forming surface, wherein, when at a rearward position thereof, the frame, the inflatable peripheral seal and the ice-forming surface create a mold for forming the ice block therein.

[0024] In some embodiments, at an ice harvesting stage which harvests the ice block formed within the mold, a specified force which tends to drive the frame in the forward direction is applied at a predetermined sequence of locations on a perimeter of the frame, to break a bond between the ice block and the ice-forming surface.

[0025] In some embodiments, the axial movement of the frame is controlled by a combination of (i) independently operating one or more actuators attached to respective locations around a perimeter of the frame, and (ii) inflating and deflating the inflatable peripheral seal.

[0026] In some embodiments, the specified force is applied by (i) inflating the inflatable peripheral seal to a predetermined internal pressure, and (ii) selectively operating the one or more actuators, according to the predetermined sequence of locations.

[0027] There is also provided, in an embodiment, an ice-forming method comprising: providing an ice-forming stack, comprising an ice-making portion comprising an evaporator having a forward face, an elastomeric pad disposed over the forward face, a thin planar sheet disposed over a forward surface of the elastomeric pad, and a polymeric film disposed over a forward surface of the sheet, wherein a forward surface of the polymeric film defines an ice-forming surface for forming an ice block thereon, wherein the ice-forming surface comprises one or more openings configured to release pressurized fluid between the ice-forming surface and the ice block formed thereon; chilling the ice-making portion, which causes the ice-froing surface to chill; circulatingwater over the ice-forming surface, thereby forming the ice block thereon; and releasing the pressurized fluid between the ice-forming surface and the ice block formed thereon.

[0028] In some embodiments, the releasing of the pressurized fluid applies a compressive force which causes a plurality of regions of the ice-forming surface and the sheet to deflect in a rearward direction against the elastomeric pad, thereby breaking a bond and separating between the ice-forming surface and the ice block formed thereon.

[0029] In some embodiments, the sheet comprises one or more slots spaced apart about a surface thereof, wherein each of the slots defines a thin elongated cut in the surface of the sheet, wherein the slots are configured to facilitate the deflection of the sheet and the ice-forming surface.

[0030] In some embodiments, the elastomeric pad is configured to locally resiliently reduce in thickness, in response to the deflection in the region by the ice-forming surface and the sheet.

[0031] In some embodiments, the forward face of the evaporator comprises one or more channels, each defining a groove having a rectangular, semicircular, or V-shaped ross-sectional shape, wherein the reduction in thickness comprises at least partially a displacement of portions of the elastomeric pad into the channels.

[0032] In some embodiments, the elastomeric pad is formed of a thermally- conductive material having thermal conductivity in the range of 15-50 W / m-k, a thickness of between 0.5-3 mm, and a hardness of between 10-50 on the Shore E- hardness scale.

[0033] In some embodiments, the elastomeric pad is configured to removably adhere to the forward face using a thermal compound.

[0034] In some embodiments, the sheet comprises a flexible planar stainless steel sheet having a substantially uniform thickness of between 20-60 pm, and a smooth, polished, or mirror finish over a forward face thereof.

[0035] In some embodiments, the sheet is configured to removably adhere to the forward surface of the elastomeric pad using a thermal compound.

[0036] In some embodiments, the polymeric film is made of a food-safe material, has a thickness of between 10-60 pm, and a hardness of between 10-40 on the Shore A- hardness scale.

[0037] In some embodiments, the polymeric film is configured to removably selfadhere to the forward surface of the sheet.

[0038] In some embodiments, the forward surface of the polymeric film comprises one or more relief regions adapted to impress or emboss a design onto the ice block formed thereon, wherein each of the one or more relief regions comprises a set of projections extending from the forward surface of the film.

[0039] In some embodiments, the ice-forming stack is incorporated into an icemaking system which further comprises: (i) a control unit; (ii) a refrigeration unit configured to perform the chilling of the ice-making portion; (iii) a fluid compressor configured to supply the pressurized fluid; and (iv) a water pumping unit configured to perform the circulating.

[0040] In some embodiments, the ice-making system further comprises an iceharvesting stack, comprising: (i) a frame disposed such that a perimeter rearward face thereof is in opposed facing relation with the ice-forming surface, wherein the frame is movable axially in the forward and rearward directions relative to the ice-forming surface; and (ii) an inflatable peripheral seal disposed between the rearward face of the frame and the ice-forming surface, wherein, when at a rearward position thereof, the frame, the inflatable peripheral seal and the ice-forming surface create a mold for forming the ice block therein.

[0041] In some embodiments, the method further comprises applying a specified force which tends to drive the frame in the forward direction, wherein the force is applied at a predetermined sequence of locations on a perimeter of the frame, to break a bond between the ice block and the ice-forming surface.

[0042] In some embodiments, the axial movement of the frame is controlled by a combination of (i) independently operating one or more actuators attached to respective locations around a perimeter of the frame, and (ii) inflating and deflating the inflatable peripheral seal.

[0043] In some embodiments, the specified force is applied by (i) inflating the inflatable peripheral seal to a predetermined internal pressure, and (ii) selectivelyoperating the one or more actuators, according to the predetermined sequence of locations.

[0044] There is further provided, in an embodiment, an ice-harvesting stack for an ice-making system, comprising: a frame disposed such that a perimeter rearward face thereof is in opposed facing relation with the ice-forming surface, wherein the frame is movable axially in the forward and rearward directions relative to the ice-forming surface; and an inflatable peripheral seal disposed between the rearward face of the frame and the ice-forming surface, wherein, when at a rearward position thereof, the frame, the inflatable peripheral seal and the ice-forming surface create a mold for forming of an ice block therein.

[0045] In some embodiments, the ice-forming surface defines a forward surface of an ice-making portion which comprises: (i) an evaporator having a forward face; (ii) an elastomeric pad disposed over the forward face; (iii) a thin planar sheet disposed over a forward surface of the elastomeric pad; and (iv) a polymeric film disposed over a forward surface of the sheet, wherein a forward surface of the polymeric film defines an ice-forming surface for forming an ice block thereon.

[0046] In some embodiments, the ice-forming surface comprises one or more openings configured to release pressurized fluid between the ice-forming surface and the ice block formed thereon.

[0047] In some embodiments, the pressurized fluid applies a compressive force which causes a plurality of regions of the ice-forming surface and the sheet to deflect in a rearward direction against the elastomeric pad, thereby breaking a bond and separating between the ice-forming surface and the ice block formed thereon.

[0048] In some embodiments, the ice-harvesting stack is configured to apply a specified force which tends to drive the frame in a forward direction relative to the iceforming surface, wherein the force is applied at a predetermined sequence of locations on a perimeter of the frame, to break a bond between the ice block and the ice-forming surface.

[0049] In some embodiments, the axial movement of the frame is controlled by a combination of (i) independently operating one or more actuators attached to respective locations around a perimeter of the frame, and (ii) inflating and deflating the inflatable peripheral seal.

[0050] In some embodiments, the specified force is applied by (i) inflating the inflatable peripheral seal to a predetermined internal pressure, and (ii) selectively operating the one or more actuators, according to the predetermined sequence of locations.

[0051] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed description.BRIEF DESCRIPTION OF THE FIGURES

[0052] Exemplary embodiments are illustrated in referenced figures. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.

[0053] FIG. 1A depicts schematically an ice-making system incorporating an icemaking stack of the present disclosure, configured for making and non-heated harvesting of ice blocks.

[0054] FIGS. 1B-1C depict schematically the various components of an ice-making stack of the present invention.

[0055] FIG. ID depicts schematically the various components of an ice harvesting stack of the present invention.

[0056] FIGS. 2A-2C schematically depict an ice-making stack and an ice harvesting stack of the present invention in side-view.

[0057] FIGS. 3A-3D depict an exemplary ice-forming portion of the present disclosure, in front, perspective, back, and side views, respectively.

[0058] FIGS. 4A-4B depict an exemplary pad of the present disclosure, in front and side views, respectively.

[0059] FIGS 5A-5B depict an exemplary sheet of the present disclosure, in front and side views, respectively.

[0060] FIGS. 6A-6B, depict an exemplary film of the present disclosure, in front and side views, respectively.

[0061] FIGS. 6C-6E schematically depict the process of dispensing pressurized fluid during an ice harvesting stage of the present disclosure.

[0062] FIGS. 7A-7B depict a peripheral seal of the present disclosure.

[0063] FIGS. 7C-7D are cross-sectional views of a peripheral seal of the present disclosure.

[0064] FIGS. 8A-8C depict an ice-forming frame of the present disclosure, in front, side cross-section, and back views, respectively.

[0065] FIG. 9 is a flowchart of the functional steps in a method for operating an icemaking stack of the present disclosure, as may be incorporated into an ice-making system.

[0066] FIGS. 10A-10E depict an ice-making stage using an ice-making system incorporating an ice-making stack and an ice harvesting stack of the present invention of the present disclosure.

[0067] FIG. 11 is a flowchart of the functional steps in a method for operating an icemaking stack and an ice harvesting stack of the present disclosure, as may be incorporated into an ice-making system, in an ice harvesting stage.

[0068] FIGS. 12A-12C and 13A-13B depict an ice harvesting stage using an icemaking system incorporating an ice-making stack and an ice harvesting stack of the present disclosure.

[0069] FIGS. 14A-14B depict the process of dividing a formed ice block into a plurality of ice cubes.DETAILED DESCRIPTION

[0070] Disclosed herein are a system and method for non-heated extraction or harvesting of ice blocks formed over a chilled evaporator of an ice machine, in a way which preserves the integrity of the formed ice block, without melting or degrading any surface of the formed ice block.

[0071] In some embodiments, the present system is particularly useful in the context of ice blocks which are formed using a special mold or imprint template which renders a motif or relief onto the surface of the ice during the ice-forming process, such as a graphic, an image, a logo, a writing, or another visible pattern. The imprinting is createdby freezing the ice over a vertical evaporator surface, which may be covered by an imprinting film. The imprinting film comprises reliefs of a desired image or design, of which a negative impression is transferred to the surface of the ice as it is being formed. Non-heated, minimal-forced or non-forced extraction or harvesting of the formed ice ensures the preservation of the integrity of the imprinted relief, without melting or otherwise degrading the imprinted surface of the formed ice blocks

[0072] In some embodiments, the present system may be incorporated within an automated ice machine comprising a vertical evaporator panel. In some embodiments, an imprinting film may be attached to a forward face of a vertical chilled evaporator surface (however, one or more additional layers may be disposed between the evaporator and the imprinting film).

[0073] During the ice-making operation, water cascades continuously over the vertical chilled evaporator surface (which may be covered by the imprinting film), which causes chilling and freezing of the water. In each pass, a portion of the flowing water freezes, while excess water quantity runs off and is collected into a sump. The water collected in the sump is then recirculated over the chilled imprinting film by a suitable pump. This operation continues to create ice buildup over the vertical chilled evaporator surface, until the formed ice block has achieved a desired thickness. The resulting ice block is thus formed layer by layer from clear ice, because the constant washing with excess water avoids impurities (such as dissolved air and minerals) which affect the appearance of the. However, the ice block forms a strong bond with the evaporator surface / imprinting film surface, which must be broken for the ice block to be harvested. Typically, the formed ice block is harvested using some combination of heating the evaporator and mechanical means.

[0074] However, in the case of an ice block imprinted with a design, care must be taken to preserve the integrity of the imprinted surface, which is formed from thin raised or recessed lines of ice, and can therefore be easily damaged. For example, extraction of the ice block via heating of the evaporator surface will result in melting a layer of formed ice which in direct contact with the evaporator / imprinting film surface, which will inevitably damage the surface of the ice block and any imprinting thereon. Similarly, extraction of the ice block by separating it from the evaporator surface using mechanical force risks damaging the surface of the ice block in direct contact with the evaporator.

[0075] Reference is made to FIG. 1A which depicts an ice-making system 100, incorporating an ice-making stack 110 and an ice harvesting stack 150, according to the present disclosure, configured, respectively, for making and for non-heated harvesting of ice blocks. FIGS. 1B-1C depict schematically the various components of ice-making stack 110 of the present invention. FIG. ID depicts schematically the various components of ice harvesting stack 150 of the present invention. FIGS. 2A-2C schematically depict ice-making stack 110 in side-view. In FIG. 2A, ice-making stack 110 and ice harvesting stack 150 are shown in a compacted view, wherein the various elements of ice-making stack 110 and ice harvesting stack 150 are stacked in close proximity, similarly to the way they are stacked in use. In FIG. 2B, ice-making stack 110 and ice harvesting stack 150 are shown in spaced-apart view, wherein the various components of ice-making stack 110 and ice harvesting stack 150 are spread out in relation to one another, to afford a better view of these components. During operation, the various components of ice-making stack 110 and ice harvesting stack 150 are generally in contact engagement with one another at least part of the time, as will be further detailed below.

[0076] Reference is made back to FIG. 1A, which schematically depicts ice-making system 100, incorporating ice-making stack 110 and ice harvesting stack 150 of the present disclosure. Ice machine 100 may comprise a control unit 102, configured to control and operate the various components of ice machine 100. Control unit 102 operates:A refrigeration unit 104, configured to chill an ice-forming portion 112 of icemaking stack 110.A fluid compressor 106, configured to pressurize fluids, such as gasses.A pumping unit 108, configured to pump and recirculate water for ice-making. Pumping unit 108 pumps and circulates water from a water source of ice machine 100. The excess water is collected and recirculated over ice-forming portion 112 continuously during the ice-forming stge.

[0077] As used throughout this description, the terms ‘axial’ and ‘axially’ are used to denote a direction parallel to an axis X-X, shown for example in FIGS. 2A-2B. The terms ‘lateral’ or ‘laterally’ are used to denote a direction which is on a plane that is perpendicular to axis X-X, as defined for example by a forward surface 114 (shown,best in FIG. IB) of ice-forming portion 112. The term ‘forward’ is used to denote a direction extending perpendicularly and away from forward surface 114 along axis X- X, while ‘rearward’ is used to denote the opposite direction, towards the back of iceforming portion 112.

[0078] With reference to FIG. IB, by way of overview, in some embodiments, icemaking stack 110 comprises:An ice-forming portion 112, formed from a material having high thermal conductivity, such as copper, aluminum, bronze, and the like. Ice-forming portion 112 has a substantially vertical and generally rectangular forward-facing surface 114. Forward surface 114 is in heat-exchange communication with an evaporator 116 (best shown in FIG. 3C). In some embodiments, evaporator 116 may comprise refrigerant channels formed in a serpentine or similar shape, in thermal contact with forward surface 114 of the ice-forming portion 112. Evaporator 116 is connected to refrigeration unit 104 (shown in FIG. 1 A), which may comprise a compressor configured to compress a refrigerant and deliver it to a condenser. The condenser condenses the refrigerant into a liquid, which is conducted to the evaporator, where it vaporizes and chills evaporator 116, which in turn chills forward surface 114 of the ice-forming portion 112.In some embodiments, forward surface 114 of ice-forming portion 112 comprises a series of vertical, horizontal, diagonal, circular, spiral, and / or serpentine channels 118, each defining a rectangular, semicircular, V-shaped, or similar groove or series of grooves formed in forward surface 114 of iceforming portion 112.A pad 120, dimensioned and configured to removably adhere to, and cover at least a portion of, forward surface 114. Pad 120 comprises a relatively thin and flat layer of an elastomeric material having high thermal conductivity, that is at least locally resiliently-deformable or resiliently-compressible, such that it reduces in thickness in response to a compressive load. As used herein, the terms “resiliently-deformable” or “resiliently-compressible” refer to a mechanical property of pad 120 which allows one or more regions of pad 120 to be reduced in thickness by the application of a compressive force, and to resiliently return to their original thickness upon cessation of the load. In some embodiments, thelocal reduction in thickness is enabled by deformation and / or displacement of the pad material, for example, by extrusion into one or more channels 118 in forward surface 114, as shall be further detailed below.A sheet 130, dimensioned and configured to attach to and substantially cover the area of pad 120. Sheet 130 comprises a thin, flexible and resilient planar sheet, which may be formed of any suitable sheet material, such as sheet stainless steel, steel, phosphor bronze, copper, nickel silver, brass, beryllium copper, and / or another material with similar properties.In a first variation of ice-making stack 110, as shown in FIGS. IB and 2B, sheet 130 is covered by an optional film 140 which forms an ice-forming surface 144, on which an ice block is formed. In such cases, the ice block is created over film 140. In other cases, as shown in FIGS. 1C and 2C, sheet 130 forms ice-forming surface 144, on which an ice block is formed.In cases in which sheet 130 is covered by film 140 (FIGS. IB and 2B), the one or more openings 132 communicate the pressurized fluid through sheet 130 to corresponding holes 143 in film 140, so as to inject the pressurized fluid between film 140, which forms ice-forming surface 144, and the formed ice block, as shall be further detailed hereinbelow.In a second variation of ice-making stack 110, sheet 130 forms ice-forming surface 144 (FIGS. 1C and 2C) sheet 130 comprises one or more openings 132 for injecting pressurized fluid between ice-forming surface 144 and the formed ice block, as shall be further detailed below. Openings 132 are sealed to prevent back leakage of the pressurized fluid through openings 132.In some embodiments sheet 130 is configured to depress or deflect in the rearward direction is response to a biasing force, such as may be applied by compressed fluid, in an axis perpendicular to its plane, to facilitate separation of ice-forming surface 144 from an ice block formed thereon, as shall be further detailed hereinbelow. In some embodiments, sheet 130 is configured to deflect or depress between 20-60 microns in the rearward direction. In some embodiments, sheet 130 is configured to provide for progressive, substantially even deflection about its plane in response to local biasing forces, as shall be further detailed below.In some embodiments, sheet 130 comprises a series of cut-through notches or slots 134, spaced apart about the surface of sheet 130. In some embodiments, slots 134 define vertical, horizontal, circular, spiral, and / or serpentine thin elongated cuts in the surface of sheet 130. In some embodiments, slots 134 are configured to facilitate the rearward deflection of depression of sheet 130.Optionally, a film 140 (shown in FIG. IB) dimensioned and configured to removably adhere to, and substantially cover the area of, sheet 130. In some embodiments, film 140 is a food-safe thin polymeric sheet made of one or more of the following polymeric materials: silicone, polyurethane, polyethylene, polypropylene, polyvinylchloride (PVC), and / or another similar polymer.Film 140 comprises one or more holes 143 corresponding to the one of more openings 132 in sheet 130. Holes 143 are configured to inject the pressurized fluid between film 140, which forms ice-forming surface 144, and the formed ice block, as shall be further detailed hereinbelow.In some embodiments, film 140 is a fluid-tight film configured to prevent fluids (including water used for ice-making and / or pressurized gas used to facilitate ice extraction) from leaking or diffusing through ice-forming surface 144.Optionally, a forward surface of film 140 (which defines ice-forming surface 144) is affected by one or more relief regions adapted to impress or emboss any desired pattern or figure on the forming ice bloc, such as a logo, a writing, an image, and the like.

[0079] With reference to FIG. ID, by way of overview, in some embodiments, ice harvesting stack 150 comprises:Peripheral seal 152 formed between a perimeter of ice-forming surface 144 and frame 160. Peripheral seal 152 is configured to be inflated and deflated substantially in a direction that is perpendicular to ice-forming surface 144, to provide a perimeter seal between ice-forming surface 144 and frame 160, as shall be further detailed below.Frame 160, configured to be moved substantially axially in the forward or rearward directions along axis X-X, using one or more actuators. When perimeter frame 160 is at its most rearward position, perimeter frame 160, ice-forming surface 144, and peripheral seal 152, create a mold for forming an ice block therein.

[0080] Refrigeration unit 104 (shown in FIG. 1A) is thermally connected to evaporator 116. Refrigeration unit 104 may comprise a compressor configured to compress a refrigerant and deliver it to a condenser. The condenser condenses the refrigerant into a liquid, which is conducted to evaporator 116, where it vaporizes and chills evaporator 116.

[0081] Fluid compressor 106 (shown in FIG. 1A) provides pressurized fluid as needed during the ice harvesting stage, e.g., via conduits 136, to be dispensed through openings 132, or to inflate / deflate peripheral seal 152. Control unit 102 (shown in FIG. 1A) may control the operation of the ice machine and of ice-forming stack 110.

[0082] Reference is now made to FIGS. 3A-3D, which depict an exemplary iceforming portion 112 in front, perspective, back, and side views, respectively.

[0083] Ice-forming portion 112 may be formed from a material having high thermal conductivity, such as copper, aluminum, bronze, and the like. In some embodiments, ice-forming portion 112 may be cast or otherwise formed as a one-piece panel. In some embodiments, ice-forming portion 112 has a thermal conductivity in the range of SOO- SOO W / m - k.

[0084] In some embodiments, ice-forming portion 112 defines a generally rectangular and substantially vertical forward surface 114. In some embodiments, forward surface 114 has a height of approximately 400 mm, and a width of approximately 500. In some embodiments, forward surface 114 has a smooth, polished, or mirror finish, to facilitate adhesion of pad 120 thereto, as shall be further detailed below.

[0085] In some embodiments, forward surface 114 comprises a series of spaced-apart channels 118, each defining a groove having a rectangular, semicircular, V-shaped, or similar cross-sectional shape. Channels 118 are best shown in FIG. 3B. In some embodiments, channels 118 form a grid of horizontal and vertical lines, as shown. However, channels 118 may define vertical, horizontal, diagonal, circular, spiral, serpentine or similar grooves, and / or any combination thereof.

[0086] In some embodiments, each channel 118 has a width of between 0.5-3 mm, e.g., 1.5 mm, and a depth of between 0.5-3 mm, e.g., 1.5 mm. In some embodiments, the channels 118 are spaced apart laterally from one another between 20- 80mm.

[0087] In some embodiments, channels 118 provide space for accommodating displaced or deformed portions of pad 120, which may partially extrude into channels 118 when pad 120 is under compressive load during an ice harvesting operation of the present disclosure, as shall be further detailed below.

[0088] In some embodiments, forward surface 114 is in heat-exchange communication with an evaporator 116. In some embodiments, evaporator 116 may comprise refrigerant channels formed in a serpentine or similar shape, as best shown in FIG. 3C. Evaporator 116 is connected to refrigeration unit 1A (shown in FIG. 1A), which may comprise a compressor configured to compress a refrigerant and deliver it to a condenser. The condenser condenses the refrigerant into a liquid, which is conducted to the evaporator, where it vaporizes and chills evaporator 116. Evaporator 116, in turn, chills forward surface 114. As shall be further explained below, the surface temperature of chilled forward surface 114 is thermally conducted through pad 120, sheet 130, and / or film 140, which are all in contact and / or thermal engagement with one another and with forward surface 114, causing ice-forming surface 144 to chill, such that ice can be formed thereon.

[0089] In some embodiments, during an ice-making stage of the present disclosure, water cascades continuously over the substantially vertical ice-forming surface 144 (defined by forward surface 114 layered over with pad 120, sheet 130, and / or film 140), which causes some of the water to chill and freeze to form a layer of ice, while the excess quantity runs off and is collected into a sump (not shown). The water collected in the sump is then pumped and recirculated over ice-forming surface 144, whereby a next layer of ice is formed. This operation continues until the formed ice block has achieved a desired thickness. As noted above, the resulting ice block is formed layer by layer from clear ice, because the constant washing with excess water avoids impurities (such as dissolved air and / or minerals), which affect the appearance of the ice. Once formed, the ice block forms a strong bond with ice-forming surface 144, which must be broken for the ice block to be harvested.

[0090] Reference is now made to FIGS. 4A-4B, which depict an exemplary pad 120 in front and side views, respectively.

[0091] In some embodiments, pad 120 is configured to removably adhere to and cover at least a portion of forward surface 114. In some embodiments, pad 120 has a height of approximately 300 mm, and a width of approximately 420 mm.

[0092] In some embodiments, pad 120 may be removably adhered to forward surface 114 using a thermal compound having thermal conductivity on the range of 7-20 VF / m ■ k, to facilitate thermal conduction from forward surface 114 to pad 120.

[0093] Pad 120 comprises a relatively thin and flat sheet of an elastomeric material having high thermal conductivity. In some embodiments, pad 120 comprises a thermally-conductive sheet having a thickness of between 0.5-3 mm, thermal conductivity in the range of 15-50 W / m ■ k, and a hardness of between 10-50 on the Shore E-hardness scale.

[0094] In some embodiments, pad 120 is capable of being at least locally resiliently- deformed or resiliently-compressed, such that it reduces in thickness in response to a local load. In some embodiments, the local reduction in thickness is enabled by deformation and / or displacement of the pad material, for example, by extrusion into one or more channels 118 in forward surface 114.

[0095] Reference is made to FIGS 5A-5B which depict an exemplary sheet 130 in front and side views, respectively.

[0096] In some embodiments, sheet 130 is dimensioned and configured to attach to and substantially cover the area of pad 120. In some embodiments, sheet 130 may be removably adhered to a forward face of pad 120 using, e.g., a thermal compound having thermal conductivity on the range of 10-20 W / m ■ k, to facilitate thermal conduction from pad 120 to sheet 130.

[0097] In some embodiments, sheet 130 comprises a thin, flexible and resilient planar sheet, which may be formed of any suitable sheet material, such as sheet stainless steel, steel, phosphor bronze, copper, nickel silver, brass, beryllium copper, and / or another material with similar properties or another material with similar properties. In some embodiments, sheet 130 is a flexible sheet configured to deflect in response to a biasing force in an axis perpendicular to its plane, wherein the deflection is even about its plane.In some embodiments, sheet 130 is configured to deflect or depress between 20-60 microns in the rearward direction.

[0098] In some embodiments, sheet 130 has a substantially uniform thickness of between 10-60 pm (microns). In some embodiments, the forward and / or the rearward surfaces of sheet 130 have a smooth, polished, or mirror finish, to facilitate adhesion of sheet 130 to pad 120, as well as of film 140 to sheet 130, as shall be further detailed below.

[0099] In a first variation of ice-making stack 110, film 140 may be positioned to substantially cover a forward surface of sheet 130, such that film 140 forms ice-forming surface 144 on which an ice block is formed. In a second variation of ice-making stack 110, sheet 130 forms ice-forming surface 144 on which an ice block is formed.

[0100] In the first variation of ice-making stack 110 (shown for example in FIGS.IB, 2B, and 6A-6B), sheet 130 is covered by film 140, which in turn forms ice-forming surface 144. In this variation, openings 132 in sheet 130 are configured to communicate the pressurized fluid through sheet 130 to corresponding holes 143 in film 140. Film 140 is configured such that the pressurized fluid is delivered through conduits 136 and dispensed through holes 143, so as to propagate between film 140 and a block of ice formed directly thereon. In this variation, sheet 130 comprises one or more openings 132, and film 140 comprises one or more corresponding holes 143, arranged about respective forward faces thereof, e.g., in regular spaced-apart corresponding configurations. In some embodiments, sheet 130 may comprise between 1-12 openings, and film 140 comprises 1-12 corresponding holes 143, arranged in corresponding regular spaced-apart configurations about respective forward faces of sheet 130 and film 140. The pressurized fluid can be provided at a predetermined pressure by fluid compressor 106 (shown in FIG. 1A) as needed during the ice harvesting stage, e.g., via conduits 136 (as shown in FIG 6B). Holes 143 are sealed to prevent back leakage of the pressurized fluid through film 140.

[0101] In the second variation of ice-making stack 110 (shown for example in FIGS.IC, 2C, and 5A-5B), sheet 130 comprises one or more openings 132 arranged about a forward face of sheet 130, e.g., in a regular spaced-apart configuration. In some embodiments, sheet 130 may comprise between 1-12 openings, arranged in a regular spaced-apart configuration about its face. In some embodiments, openings 132 providefor dispensing a pressurized fluid (e.g., a gas) at a predetermined pressure therethrough, during an ice harvesting stage of the present disclosure. The pressurized fluid to openings 132 can be provided by fluid compressor 106 (shown in FIG. 1A) as needed during the ice harvesting stage, e.g., via conduits 136 (as shown in FIGS. 5A-5B). In this variation, sheet 130 forms ice-forming surface 144 on which an ice block is formed directly. Thus, openings 132 are configured such that the pressurized fluid is delivered through conduits 136 and dispensed through openings 132, so as to expand between ice-forming surface 144 (comprising forward face of sheet 130) and a block of ice formed directly thereon. Openings 132 are sealed against the holes in sheet 130, to prevent back leakage of pressurized fluid through openings 132.

[0102] In either one of the first and second variations, the pressurized fluid dispensed between ice-forming surface 144 (in the first variation of ice-making stack 110, comprising a forward face of sheet 130, or in the first variation of ice-making stack 110, comprising sheet 130 covered by film 140) and a block of ice formed thereon, causes ice-forming surface 144 to deflect in the rearward direction and separate from the ice block formed thereon locally, in the area adjacent openings 132. Thus, the separation of the formed block of ice from ice-forming surface 144 is facilitated.

[0103] As used herein, the terms ‘fluid,’ ‘gas,’ and / or ‘air’ may mean any fluid suitable and / or capable of being pressurized and flow in between ice-forming surface 144 (comprising a forward face of sheet 130, or sheet 130 covered by film 140, depending on the variation) and the block of ice formed thereon.

[0104] In some embodiments, a thickness and / or other mechanical properties of sheet 130 are selected such that the pressurized fluid propagates laterally around each valve or fluid opening or outlets 132, so as to cause progressive deflection of ice-forming surface 144 (comprising a forward face of sheet 130, or sheet 130 covered by film 140, depending on the variation) about much of its plane, rather than a local depression or indentation around each valve or openings 132.

[0105] In some embodiments, sheet 130 comprises a series of cut-through notches or slots 134, spaced apart about the surface of sheet 130. In some embodiments, slots 134 define vertical, horizontal, circular, spiral, and / or serpentine thin elongated cuts in the surface of sheet 130. In some embodiments, each slot 134 has a length of between 20-130 mm. In some embodiments, slots 134 are spaced apart laterally at about 25-80 mm from one another.

[0106] In some embodiments, slots 134 are configured to reduce the amount of force required to cause deflection of sheet 130, and to facilitate progressive, substantially even deflection of sheet 130 about its plane in response to local biasing forces. Accordingly, when openings 132 dispense pressurized fluid during an ice harvesting stage of the present disclosure, the pressurized fluid propagates between ice-forming surface 144 (comprising a forward face of sheet 130, or sheet 130 covered by film 140, depending on the variation) and the ice block, and causes deflection of sheet 130 in the rearward direction, against resiliently-deformable pad 120.

[0107] Reference is made to FIGS. 6A-6D, which depict an exemplary film 140 in front and side views, respectively.

[0108] Film 140 is dimensioned and configured to removably adhere to, and substantially cover, at least the area of sheet 130. In some embodiments, film 140 forms an ice-engaging forward surface of ice-making stack 110, and is thus made of a foodsafe material. In some embodiments, film 140 comprises a thin polymeric sheet having a thickness of between 10-60 pm, a hardness of between 10-40 on the Shore A-hardness scale, and a shrinkage factor of no more than 0.01 mm / mm.

[0109] In some embodiments, film 140 may be configured to removably adhere to surfaces, such as to sheet 130. In some cases, film 140 may be configured to removably self-adhere to surfaces, such as to sheet 130, by means of an inherent tackiness of the material from which it is formed, by means of a Van der Waals force, and / or by means of a suitable bonding agent, such as a pressure-sensitive adhesive. In other cases, film 140 may be configured to removably adhere to surfaces, such as to sheet 130, by treating or coating a rearward face of film 140 with a suitable compound or treatment.

[0110] In some embodiments, film 140 is a fluid-tight film configured to prevent fluids (including water used for ice-making and / or pressurized gas used to facilitate ice extraction) from leaking or diffusing through film 140.

[0111] Reference is made to FIGS. 6A-6B, which show film 140 configured as part of the first variation of ice-making stack 110 detailed hereinabove, wherein film 140 forms ice-forming surface 144. In this variation, conduits 136 are configured to deliver the pressurized fluid through openings 132 in sheet 130, to corresponding holes 143 infilm 140. Film 140 is configured such that the pressurized fluid is delivered through conduits 136 and dispensed through holes 143, and expands between film 140 and a block of ice formed directly thereon. In this variation, sheet 130 comprises one or more openings 132, and film 140 comprises one or more corresponding holes 143, arranged about respective forward faces thereof, e.g., in regular spaced-apart corresponding configurations. In some embodiments, sheet 130 may comprise between 1-12 openings, and film 140 comprises 1-12 corresponding holes 143, arranged in corresponding regular spaced-apart configurations about respective forward faces of sheet 130 and film 140. The pressurized fluid can be provided at a predetermined pressure by fluid compressor 106 (shown in FIG. 1A) as needed during the ice harvesting stage, e.g., via conduits 136 (as shown in FIG 6B). Holes 143 are sealed to prevent back leakage of the pressurized fluid through film 140.

[0112] In some embodiments, film 140 is a food- safe thin sheet made of one or more of the following materials: silicone rubber, polyurethane rubber, polyethylene, polypropylene, polyvinylchloride (PVC), polyethylene terephthalate (PET), nylon (PA), cellophane, polycarbonate (PC), EPDM rubber, latex rubber, butyl rubber, nitrile rubber, aluminum film, stainless steel film, copper film. In some embodiments, film 140 is a food- safe thin sheet which comprises a laminate of two or more layers of polymeric materials and / or metals films. In one example, film 120 may be made of a silicone rubber which may be based on a one -part or two-part polymer, and may be cured using any suitable curing system, such as a platinum-catalyzed cure system; a tin- catalyzed cure system; a condensation cure system using any suitable cross-linker, such as alkoxy, acetoxy, ester, enoxy, oxime, and the like; UV -based curing; heat-based curing; moisture-based curing; oxygen-based curing; pressure -based curing; and any combination thereof.

[0113] In some embodiments, a forward surface of film 140 (which defines iceforming surface 144) comprises one or a series of relief regions 142 adapted to impart any desired graphic design, image, logo, writing, emblem, and the like to a block of ice being formed on ice-forming surface 144.

[0114] In some embodiments, a forward surface of film 140 (i.e., ice-forming surface 144), comprises a series of relief regions 142. For example, film 140 may comprise a series of relief regions 142 (such as between 2-200 relief regions 142), arranged in anydesired arrangement, such as a row-and-column configuration over the ice-forming surface 144 of film 140 .

[0115] As noted above, film 140 may be used to impart imprinting to an ice bloc during the ice formation process. The desired arrangement of relief regions 142 over film 140 is thus transferred to the formed ice block, which now bears a negative facsimile of this arrangement.

[0116] In some embodiments, when a plurality of relief regions 142 (e.g., between 2- 200 relief regions 142) are disposed in any desired arrangement, such as a row-and- column configuration, this arrangement may define a virtual grid for later subdividing the formed ice block into uniform ice cubes, wherein each relief region 142 renders an imprinting at a desired location over the face of the individual ice cube, such as at substantially the center of the ice cube.

[0117] In such implementations, this virtual grid defined by the configuration of relief regions 142 corresponds to a cutting grid used by ice-making system 100 for subdividing the formed block of ice into ice cubes. For example, ice-making system 100 may use a grid-like arrangement of electrically heated wires or any other similar method to cut the formed ice block into uniform cubes, wherein the grid-like arrangement of electrically heated wires aligns with and corresponds to the configuration of relief regions 142.

[0118] FIGS. 6C-6E schematically depict the process of dispensing pressurized fluid during an ice harvesting stage of the present disclosure, such that the pressurized fluid propagates between ice-forming surface 144 (comprising a forward face of sheet 130 covered by film 140) and an ice block 210 formed thereon. The propagating fluid causes deflection of ice-forming surface 144 in the rearward direction, against resiliently- deformable pad 120. As can be seen in FIG. 6C, during an ice harvesting stage of the present disclosure, pressurized fluid is delivered through conduits 136, and dispensed through openings 132 and corresponding holes 143 in film 140. The pressurized fluid expands and propagates between ice-forming surface 144 and ice block 210.

[0119] In FIG. 6D, the propagating pressurized fluid separates ice-forming surface 144 (comprising a forward face of sheet 130 covered by film 140) from ice block 210, by causing sheet 130 as covered by film 140 to deflect in the rearward direction, against resiliently-deformable pad 120. The rearward deflection of sheet 130 and film 140causes local reduction in thickness of pad 120, which is enabled by deformation and / or displacement of the pad material, for example, by extrusion into one or more channels 118 in forward surface 114, as shall be further detailed below.

[0120] As can be seen, the mechanical properties of sheet 130 facilitate progressive deflection of sheet 130 about its plane, beginning in the locality of valves 132 / holes143 where the pressurized fluid dispenses, and progressing laterally therefrom. In addition, slots 134 work to reduce the amount of force required to cause a desired deflection of sheet 130.

[0121] FIG. 6E shows the opposite case, where the properties and configuration of sheet 130 are not configured to facilitate progressive separation of ice-forming surface144 from ice block 210. As can be seen, in such case, the pressurized fluid simply causes local depressions or indentation in sheet 130, which would not facilitate uniform separation between the majority of the plane of ice-forming surface 144 and ice block 210.

[0122] Reference is made to FIGS. 7A-7D and 8A-8C, which depict various components of ice harvesting stack 150.

[0123] FIGS. 7A-7B depict a peripheral seal 152, which is positioned generally in contact engagement with a rearward-facing perimeter portion of frame 160 (as best shown in FIG. 8C). FIGS. 7C-7D are cross-sectional views of peripheral seal 152.

[0124] Peripheral seal 152 is dimensioned to extend around a perimeter of frame 160. Peripheral seal 152 comprises an inflatable annular chamber 154 which may extend along the length or along portions of the length of peripheral seal 152. Inflatable annular chamber 154 is configured to be alternately inflated (as shown in FIG. 7C) to one or more predetermined internal pressures, and deflated (as shown in FIG. 7D). The inflating and deflating of peripheral seal 152 is controlled by control unit 102 (shown in FIG. 1A), in accordance with a predetermined program, during the ice-making and ice harvesting stages of the present disclosure. In some embodiments, peripheral seal 152 is coupled to a pressurized fluid source, such as fluid compressor 106 shown in FIG. 1A, which may be controlled by control unit 102, to inflate and deflate peripheral seal 152 as may be required during the ice-forming and ice harvesting stages of the present disclosure.

[0125] In some embodiments, during an ice-making stage of the present disclosure, peripheral seal 152 may be inflated to a first predetermined internal pressure, to provide continuous or intermittent perimeter seal between ice-forming surface 144 and a rearward perimeter face of frame 160. Thus, perimeter frame 160, ice-forming surface 144, and inflated peripheral seal 152, create a liquid- or fluid-tight mold for forming an ice block therein.

[0126] In some embodiments, during an ice harvesting stage of the present disclosure, peripheral seal 152 may be inflated to a second predetermined internal pressure, to provide a continuous or intermittent force which tends to drive frame 160 axially in the forward direction, to facilitate extraction of harvesting of a formed ice block.

[0127] Reference is made to FIGS. 8A-8C, which depict an ice-forming frame 160 in front, side cross-section, and back views, respectively.

[0128] In some embodiments, frame 160 is movable generally axially in the forward or rearward directions along axis X-X. In some embodiments, frame 160 is movable axially using one or more actuators 180 (schematically shown in FIG. 8B). Actuators 180 may be hydraulic, pneumatic, or electro-mechanical actuators, or may comprise a rack-and-pinion system or any similar drive mechanism. In some embodiments, frame 160 is selectively movable axially by inflating and deflating peripheral annular chamber 154 of seal 152 and / or by operating actuators 180.

[0129] In some embodiments, ice harvesting stack 150 comprises a single actuator configured to drive frame 160 axially in the forward or rearward directions along axis X-X. In some embodiments, ice harvesting stack 150 comprises between 2-8 actuators, disposed about a perimeter of frame 160, wherein each of actuators 180 may be operated selectively and individually. For example, ice harvesting stack 150 may comprise 2 actuators, each located at respective midpoints of opposing sides of frame 160. In another example, ice harvesting stack 150 may comprise 4 actuators, located respectively at midpoints of the sides of frame 160. In yet another example, ice harvesting stack 150 may comprise 4 actuators, located respectively at corners (vertex) of frame 160. In yet another example, ice harvesting stack 150 may comprise 8 actuators, located respectively at midpoints of the sides and at comers of frame 160.

[0130] When frame 160 is at the rearward-most position of its axial travel range, peripheral seal 152, which is attached to a rearward-facing perimeter portion of frame160, is in contact engagement, or at least in close proximity to, a perimeter of iceforming surface 144. Thus, when frame 160 is in the rearward-most position of its axial travel range, ice-forming surface 144, frame 160, and peripheral seal 152, create a liquid- or fluid-tight mold in which an ice block may be formed.

[0131] Reference is made to FIG. 9, which is a flowchart of the functional steps in a method 900 for operating ice-making stack 110 and ice harvesting stack 150 of the present disclosure, as may be incorporated into an ice-making system, such as icemaking system 100 shown in FIG. 1A, during an ice-making stage. The steps of method 900 will be discussed with continued reference to FIGS. 10A-10E, which depict an icemaking stage using an ice-making system such as shown in FIG. 1A, incorporating an ice-making stack 110 and ice harvesting stack 150 of the present disclosure.

[0132] Steps of method 900 may either be performed in the order they are presented or in a different order (or even in parallel), as long as the order allows for a necessary input to a certain step to be obtained from an output of an earlier step. In addition, the steps of method 200 are performed automatically (e.g., as controlled by control unit 102 of FIG. 1A), unless specifically stated otherwise.

[0133] For clarity purposes, ice-making stack 110 is shown in FIGS. 10A-10E as a single element, without showing its individual components — ice-forming portion 112, pad 120, sheet 130, and / or film 140 — separately. However, it is understood that in use, ice-making stack 110 includes ice-forming portion 112, pad 120, sheet 130, and film 140, layered in this order and in contact engagement with one another. Accordingly, the following discussion will refer generally to “ice-forming surface 144,” as defined and disclosed hereinabove, which is defined by pad 120, sheet 130, and film 140 layered over forward surface 114 of ice-forming portion 112. Similarly, the respective roles of ice-forming portion 110, pad 120, sheet 130, and film 140 will be detailed in the description of the various steps of method 900.

[0134] Method 900 begins in step 902, wherein an ice-making system, such as shown in FIG. 1A, comprising ice-making stack 110 and ice harvesting stack 150, may be provided, as shown in FIG. 10A.

[0135] Ice-making stack 110 comprises an ice-forming portion 112 having an iceforming surface 144 (comprising, as explained above, forward surface 114 with pad120, sheet 130, and film 140 layered thereon). Ice harvesting stack 150 comprises frame 160 having peripheral seal 152 attached to a rearward-facing perimeter surface thereof.

[0136] In step 904, as shown in FIG. 10B, actuators 180 may be configured to move frame 160 to its rearward-most positions, wherein peripheral seal abuts ice-forming surface 144. In this position, perimeter frame 160, ice-forming surface 144, and peripheral seal 152 create a mold for forming an ice block therein.

[0137] In some embodiments, actuators 180 may be operated to lock frame 160 in its rearward most position. In some embodiments, actuators 180 may be operated to lock frame 160 in its rearward most position by applying a first predetermined amount of rearward-acting force which tends to drive frame 160 in the rearward direction. In some embodiments, the first predetermined force may be equal to between 10-30 kgf.

[0138] At or about the same time, control unit 102 may operate fluid compressor 106 of FIG. 1A to provide pressurize fluid to inflatable annular chamber 154 of peripheral seal 152, such that it is inflated to a first internal pressure, which may be between 20- 60 kPa. Thus, peripheral seal 152 provides a liquid- or fluid-tight seal between iceforming surface 144 and the rearward facing perimeter surface of frame 105, to create an ice-making mold.

[0139] In step 906, as still shown in FIG. 10B, control unit 102 of FIG. 1A may begin an ice-making stage, by operating refrigeration unit 104 to chill ice-forming portion 112 of ice-making stack 110, e.g., by flowing a compressed refrigerant through evaporator 116, which in turn chills forward surface 114 of ice-forming portion 112. Control unit may also operate pumping unit 108 to flow water 200 continuously over ice-forming surface 144, which causes chilling and freezing of the water. As noted above, in this process, only part of the flowing water freezes, wherein the excess quantity runs off and is collected into a sump. The water collected in the sump is then recirculated over the evaporator panel by pumping unit 108.

[0140] As shown in FIG. 10C, an ice block 210 begins to form within the mold created by ice-forming surface 144 and frame 160, as sealed by peripheral seal 152 inflated to the first internal pressure.

[0141] In step 908, as shown in FIG. 10D, the ice-making operation continues until the formed ice block 210 has achieved a desired thickness. The formed ice block is bonded (i) at a rearward face thereof to ice-forming surface 144, and (ii) peripherally,at side faces thereof, to an internal perimeter surface of frame 160 (shown in FIGS. 10A-10D is cross-section).

[0142] As noted above, the resulting ice block 210 is formed layer by layer from clear ice, because the constant washing with excess water avoids impurities which affect the appearance of the ice.

[0143] In step 910, as can be seen in FIG. 10E, at the conclusion of the ice-making stage, control unit 102 may initiate a wind-down stage, in which the chilling of iceforming portion 112 by refrigeration unit 106 is stopped, but the circulating of water 200 may continue for a specified period of time, e.g., between 30-240 seconds. During the wind-down stage, the temperature of ice block 210 begins to increase under the effect of the ambient temperature, and ice block 210 expands slightly. Accordingly, control unit 102 may operate actuators 180 to release frame 160 from its locked position achieved in step 904, and release all or most of the internal pressure in inflatable annular chamber 154 of seal 152, to allow relatively free axial movement of frame 160 along axis X-X, as ice block 210 expands or otherwise moves. In some embodiments, control unit 102 may operate actuators 180 to release frame 160 from its locked position achieved in step 904 in a gradual manner, e.g., by reducing the amount of the first rearward-acting specified force applied by actuators 180, during all or part of the winddown period. In some embodiments, control unit 102 may operate actuators 180 to continue to apply the first rearward- acting specified force which is equal to between 10-30 kgf, during all or at least part of the wind-down period.

[0144] Reference is made to FIG. 11, which is a flowchart of the functional steps in a method 920 for operating an ice-making stack 110 of the present disclosure, as may be incorporated into an ice-making system, such as ice-making system 100 shown in FIG. 1 A, during an ice harvesting stage. The steps of method 920 will be discussed with continued reference to FIGS. 12A-12C and 13A-13B, which depict an ice harvesting stage using an ice-making system such as shown in FIG. 1A, incorporating an icemaking stack 110 of the present disclosure.

[0145] Steps of method 920 may either be performed in the order they are presented or in a different order (or even in parallel), as long as the order allows for a necessary input to a certain step to be obtained from an output of an earlier step. In addition, thesteps of method 200 are performed automatically (e.g., as controlled by control unit 102 of FIG. 1A), unless specifically stated otherwise.

[0146] As in FIGS. 10A-10E, for clarity purposes, ice-making stack 110 is shown in FIGS. 10A-10E as a single element, without showing its individual components — iceforming portion 112, pad 120, sheet 130, and / or film 140 — separately. However, it is understood that in use, ice-making stack 110 includes ice-forming portion 112, pad 120, sheet 130, and film 140, layered in this order and in contact engagement with one another. Accordingly, the following discussion will refer generally to “ice-forming surface 144,” as defined and disclosed hereinabove, which is defined by pad 120, sheet 130, and film 140 layered over forward surface 114 of ice-forming portion 112. Similarly, the respective roles of ice-forming portion 110, pad 120, sheet 130, and film 140 will be detailed in the description of the various steps of method 900.

[0147] Method 920 begins in step 922, wherein an ice block 210 of a desired thickness has formed in accordance with the steps of method 900, within a mold created by ice-making stack 110 of the present disclosure, comprising ice-forming surface 144 and the rearward facing perimeter surface of frame 105, as sealed by peripheral seal 152. In some embodiments, ice-making stack 110 may be incorporated into an icemaking system, such as shown in FIG. 1A.

[0148] In step 924, as can be seen in FIGS. 12A-12B, control unit 102 may operate fluid compressor 106 to provide pressurized fluid to inflatable annular chamber 154 of peripheral seal 152, such that it is inflated to a second internal pressure, which may be approximately 40-90 kPa. This causes peripheral seal 152 to (i) provide an air-tight seal around a perimeter of frame 160, and (ii) apply a specified amount of uniform force around a perimeter of frame 160, which tends to drive frame 160 as a whole in the forward direction, wherein ice block 210 is bonded at side faces thereof peripherally to an internal perimeter surface of frame 160. Concurrently, control unit 102 may operate actuators 180 to apply a second specified counteracting force which tends to drive frame 160 in the rearward direction, equal to approximately 60-120 kgf.

[0149] In step 926, as depicted by FIGS. 12A-12B, control unit 102 may begin to execute one or more release cycles, configured to release ice block 210 from its bond to ice-forming surface 144.

[0150] In some embodiments, the release cycles of step 926 are effected via a combination of (i) selectively independently operating one or more of actuators 180, to apply forward-acting release force in the forward direction, locally at respective locations around a perimeter of frame 160, concurrently with (ii) inflating and deflating the peripheral seal 152, to apply a specified amount of uniform force around the perimeter of frame 160, which tends to drive frame 160 as a whole in the forward direction. Accordingly, in some embodiments, the release cycles of step 926 comprise applying a specified release force in the forward direction, wherein the force is applied locally at a predetermined sequence of locations on the perimeter of frame 160, concurrently with inflating peripheral seal 152 to a second predetermined internal pressure, to provide a continuous or intermittent force which tends to drive frame 160 as a whole. The operating of each actuator 180 may continue for a specified periods of time, e.g., between 0.5-2 seconds, upon which the actuator is operated again to re-apply a rearward-acting force at the respective location, and a next one or more of actuators 180 is operated to apply a forward-acting force. For example, as can be seen schematically in FIG. 12A, actuator 180a is operated to apply a release force in the forward direction, while actuator 180b continues to apply a force in the rearward direction. In FIG. 12B, actuator 180b is now operated to apply a release force in the forward direction, while actuator 180a applies a force in the rearward direction. The predetermined sequence of locations at which a specified release force in the forward direction is applied by actuators 180 may comprise any suitable or desirable sequence of operating actuators 180 selectively, e.g., by sequentially operating actuators 180 around the perimeter of frame 160 in a round-robin fashion, by alternately operating actuators 180 located on opposing sides or comers of frame 160, etc.

[0151] In some variations, the release cycles of step 926 comprise (i) inflating and deflating the peripheral seal 152, to apply a specified amount of a continuous or intermittent uniform force around the perimeter of frame 160, which tends to drive frame 160 as a whole in the forward direction, concurrently with (ii) selectively independently operating one or more of actuators 180 by releasing a rearward-acting force applied by each one of the actuators 180, locally at a predetermined sequence of locations on the perimeter of frame 160. Accordingly, each release cycle comprises releasing the rearward-acting force applied by one or more actuators 180 according to a predetermined sequence, such that no rearward-acting force is applied locally at thelocation of the released actuator 180. This is done while peripheral seal 152 is inflated to the second predetermined internal pressure, to provide a continuous or intermittent force which tends to drive frame 160 as a whole in the forward direction. The release of each actuator 180 may continue for a specified periods of time, e.g., between 0.5-2 seconds, upon which the released actuator is operated again to re-apply a rearwardacting force at the respective location, and a next one or more of actuators 180 are released. In some embodiments, each release cycle may comprise serially releasing and re-applying the countering tension force applied by each of actuators 180 between 1-6 times. For example, as can be seen schematically in FIG. 12A, actuator 180a is released such that it doesn't apply a force in the rearward direction, while actuator 180b continues to apply a force in the rearward direction. In FIG. 12B, actuator 180a is now release such that it does not apply a force in the rearward direction, while actuator 180a applies a force in the rearward direction. The predetermined sequence of locations at which the specified rearward-acting force applied by each the actuators 180 is released may comprise any suitable or desirable sequence of operating actuators 180 selectively, e.g., by sequentially operating actuators 180 around the perimeter of frame 160 in a round-robin fashion, by alternately operating actuators 180 located on opposing sides or comers of frame 160, etc.

[0152] Reference is now made to FIGS. 13A-13B, which schematically depict the process of dispensing pressurized fluid through openings 132 and holes 143 during an ice harvesting stage of the present disclosure, such that the pressurized fluid propagates between ice-forming surface 144 (comprising a forward face of sheet 130 covered by film 140) and ice block 210 formed thereon, and causes deflection of sheet 130 in the rearward direction, against resiliently-deformable pad 120.

[0153] As can be seen in FIGS. 13A-13B, in some embodiments, prior to, or at least partially concurrently with, operating the release cycles described immediately above with reference to step 926 of method 920, control unit 102 may operate fluid compressor 106 to deliver pressurized fluid via conduits 136, to be dispensed through valves or opening 132 in sheet 130 and corresponding holes 143 in film 140. Film 140 is configured such that the pressurized fluid is dispensed through holes 143, and expands between film 140 and ice block 210 formed directly thereon.

[0154] As can be seen in FIG. 13B, the propagating pressurized fluid tends to separate ice-forming surface 144 (comprising a forward face of sheet 130 covered by film 140)from ice block 210, by causing sheet 130 (as covered by film 140) to depress or deflect in the rearward direction, against pad 120. In some embodiments, channels 118 disposed about forward surface 114 of ice-forming portion 112 (shown schematically in FIGS. 13A-13B) provide space for accommodating deformed or displaced portions of pad 120, which may partially extrude into channels 118, when pad 120 is under compressive load during an ice harvesting operation of the present disclosure.

[0155] At the conclusion of step 926, ice block 210 is released from its bond at a rearward face thereof to ice-forming surface 144 (comprising a forward face of sheet 130, or sheet 130 covered by film 140, depending on the variation).

[0156] In step 928, as can be seen in FIG. 12C, control unit 102 may operate actuators 180 to drive frame 160 in the forward direction, to harvest ice block 210. In some embodiments, ice block 210 may then be released from its peripheral bond to the internal perimeter surface of frame 160.

[0157] In some embodiments, a forward surface of film 140 (i.e., ice-forming surface 144), comprises a series of relief regions 142. For example, film 140 may comprise a series of relief regions 142 (such as between 2-200 relief regions 142), arranged in any desired arrangement, such as a row-and-column configuration over the ice-forming surface 144 of film 140 .

[0158] As noted above, film 140 may be used to impart imprinting to ice bloc 210 during the ice formation process described with reference to method 900. The desired arrangement of relief regions 142 over film 140 is thus transferred to the formed ice block, which now bears a negative facsimile of this arrangement.

[0159] As shown in FIG. 14 A, in some embodiments, when a plurality of relief regions 142 (e.g., between 2-200 relief regions 142) are disposed in any desired arrangement over film 140, such as a row-and-column configuration, this arrangement may define a virtual grid for later subdividing the formed ice block 210 into uniform ice cubes, wherein each relief region 142 renders an imprinting 214 at a desired location over the face ice block 210.

[0160] As shown in FIG. 14B, this virtual grid defined by the configuration of relief regions 142 corresponds to a cutting grid used by ice-making system 100 for subdividing the formed ice block 210 into a plurality of ice cubes 212. For example, ice-making system 100 may use a grid-like arrangement of electrically heated wires orany other similar method to cut the formed ice block 210 into uniform cubes 212, each bearing an imprint 214 which corresponds to a respective relief region 142 on film 140.

[0161] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0162] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging / ranges between” a first indicate number and a second indicate number and “ranging / ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0163] In the description and claims of the application, each of the words “comprise” “include” and “have”, and forms thereof, are not necessarily limited to members in a list with which the words may be associated. In addition, where there are inconsistencies between this application and any document incorporated by reference, it is hereby intended that the present application controls.

[0164] The flowchart and block diagrams in the FIGures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustration, and combinations of blocks in the block diagrams and / or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

[0165] The descriptions of the various embodiments of the present invention have been presented for purposes of illustration but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

CLAIMS1. An ice-forming stack for an ice-making system, comprising: an ice-making portion comprising an evaporator having a forward face; an elastomeric pad disposed over said forward face; a thin planar sheet disposed over a forward surface of said elastomeric pad; and a polymeric film disposed over a forward surface of said sheet, wherein a forward surface of said polymeric film defines an ice-forming surface for forming an ice block thereon, wherein said ice-forming surface comprises one or more openings configured to release pressurized fluid between said ice-forming surface and said ice block formed thereon.

2. The ice-forming stack of claim 1, wherein said pressurized fluid applies a compressive force which causes a plurality of regions of said ice-forming surface and said sheet to deflect in a rearward direction against said elastomeric pad, thereby breaking a bond and separating between said ice-forming surface and said ice block formed thereon.

3. The ice-forming stack of claim 2, wherein said sheet comprises one or more slots spaced apart about a surface thereof, wherein each of said slots defines a thin elongated cut in said surface of said sheet, and wherein said slots are configured to facilitate said deflection of said sheet and said ice-forming surface.

4. The ice-forming stack of any one of claims 1-3, wherein said elastomeric pad is configured to locally resiliently reduce in thickness in response to said deflection in said region by said ice-forming surface and said sheet.

5. The ice-forming stack of claim 4, wherein said forward face of said evaporator comprises one or more channels, each defining a groove having a rectangular, semicircular, or V-shaped ross-sectional shape, and wherein said reduction in thickness comprises at least partially a displacement of portions of said elastomeric pad into said channels.

6. The ice-forming stack of any one of claims 1-5, wherein said elastomeric pad is formed of a thermally-conductive material having thermal conductivity in the rangeof 15-50 W / m ■ k, a thickness of between 0.5-3 mm, and a hardness of between 10-50 on the Shore E-hardness scale.

7. The ice-forming stack of any one of claims 1-6, wherein said elastomeric pad is configured to removably adhere to said forward face using a thermal compound.

8. The ice-forming stack of any one of claims 1-7, wherein said sheet comprises a flexible planar stainless steel sheet having a substantially uniform thickness of between 20-60 pm, and a smooth, polished, or mirror finish over said forward surface thereof.

9. The ice-forming stack of any one of claims 1-8, wherein said sheet is configured to removably adhere to said forward surface of said elastomeric pad using a thermal compound.

10. The ice-forming stack of any one of claims 1-9, wherein said polymeric film is made of a food-safe material, has a thickness of between 10-60 pm, and a hardness of between 10-40 on the Shore A-hardness scale.

11. The ice-forming stack of any one of claims 1-10, wherein said polymeric film is configured to removably self-adhere to said forward surface of said sheet.

12. The ice-forming stack of any one of claims 1-11, wherein said forward surface of said polymeric film comprises one or more relief regions adapted to impress or emboss a design onto said ice block formed thereon, and wherein each of said one or more relief regions comprises a set of projections extending from said forward surface.

13. The ice-forming stack of any one of claims 1-12, wherein said ice-making system further comprises:(i) a control unit;(ii) a refrigeration unit configured to chill said ice-making portion;(iii) a fluid compressor configured to supply said pressurized fluid; and(iv) a water pumping unit configured to circulate water over said ice-forming surface, thereby forming said ice block thereon.

14. The ice-forming stack of claim 13, wherein said ice-making system further comprises an ice-harvesting stack, comprising:(i) a frame disposed such that a perimeter rearward face thereof is in opposed facing relation with said ice-forming surface, wherein said frame is movable axially in the forward and rearward directions relative to said ice-forming surface; and(ii) an inflatable peripheral seal disposed between said rearward face of said frame and said ice-forming surface, wherein, when at a rearward position thereof, said frame, said inflatable peripheral seal and said ice-forming surface create a mold for forming said ice block therein.

15. The ice-forming stack of claim 14, wherein, at an ice harvesting stage which harvests said ice block formed within said mold, a specified force which tends to drive said frame in said forward direction is applied at a predetermined sequence of locations on a perimeter of said frame, to break a bond between said ice block and said iceforming surface.

16. The ice-forming stack of any one of claims 14 or 15, wherein said axial movement of said frame is controlled by a combination of (i) independently operating one or more actuators attached to respective locations around a perimeter of said frame, and (ii) inflating and deflating said inflatable peripheral seal.

17. The ice-forming stack of any one of claims 14-16, wherein said specified force is applied by (i) inflating said inflatable peripheral seal to a predetermined internal pressure, and (ii) selectively operating said one or more actuators, according to said predetermined sequence of locations.

18. An ice-forming method comprising: providing an ice-forming stack, comprising: an ice-making portion comprising an evaporator having a forward face, an elastomeric pad disposed over said forward face, a thin planar sheet disposed over a forward surface of said elastomeric pad, and a polymeric film disposed over a forward surface of said sheet, wherein a forward surface of said polymeric film defines an ice-forming surface for forming an ice block thereon,wherein said ice-forming surface comprises one or more openings configured to release pressurized fluid between said ice-forming surface and said ice block formed thereon; chilling said ice-making portion, which causes said ice-froing surface to chill; circulating water over said ice-forming surface, thereby forming said ice block thereon; and releasing said pressurized fluid between said ice-forming surface and said ice block formed thereon.

19. The ice-forming method of claim 18, wherein said releasing of said pressurized fluid applies a compressive force which causes a plurality of regions of said ice-forming surface and said sheet to deflect in a rearward direction against said elastomeric pad, thereby breaking a bond and separating between said ice-forming surface and said ice block formed thereon.

20. The ice-forming method of claim 19, wherein said sheet comprises one or more slots spaced apart about a surface thereof, wherein each of said slots defines a thin elongated cut in said surface of said sheet, and wherein said slots are configured to facilitate said deflection of said sheet and said ice-forming surface.

21. The ice-forming method of any one of claims 18-20, wherein said elastomeric pad is configured to locally resiliently reduce in thickness, in response to said deflection in said region by said ice-forming surface and said sheet.

22. The ice-forming method of claim 21, wherein said forward face of said evaporator comprises one or more channels, each defining a groove having a rectangular, semicircular, or V-shaped ross-sectional shape, and wherein said reduction in thickness comprises at least partially a displacement of portions of said elastomeric pad into said channels.

23. The ice-forming method of any one of claims 18-22, wherein said elastomeric pad is formed of a thermally-conductive material having thermal conductivity in the range of 15-50 W / m • k, a thickness of between 0.5-3 mm, and a hardness of between 10-50 on the Shore E-hardness scale.

24. The ice-forming method of any one of claims 18-23, wherein said elastomeric pad is configured to removably adhere to said forward face using a thermal compound.

25. The ice-forming method of any one of claims 18-24, wherein said sheet comprises a flexible planar stainless steel sheet having a substantially uniform thickness of between 20-60 pm, and a smooth, polished, or mirror finish over a forward face thereof.

26. The ice-forming method of any one of claims 18-25, wherein said sheet is configured to removably adhere to said forward surface of said elastomeric pad using a thermal compound.

27. The ice-forming method of any one of claims 18-26, wherein said polymeric film is made of a food-safe material, has a thickness of between 10-60 pm, and a hardness of between 10-40 on the Shore A-hardness scale.

28. The ice-forming method of any one of claims 18-27, wherein said polymeric film is configured to removably self-adhere to said forward surface of said sheet.

29. The ice-forming method of any one of claims 18-28, wherein said forward surface of said polymeric film comprises one or more relief regions adapted to impress or emboss a design onto said ice block formed thereon, wherein each of said one or more relief regions comprises a set of projections extending from said forward surface of said film.

30. The ice-forming method of any one of claims 18-29, wherein said ice-forming stack is incorporated into an ice-making system which further comprises:(i) a control unit;(ii) a refrigeration unit configured to perform said chilling of said icemaking portion;(iii) a fluid compressor configured to supply said pressurized fluid; and(iv) a water pumping unit configured to perform said circulating.

31. The ice-forming method of claim 30, wherein said ice-making system further comprises an ice-harvesting stack, comprising:(i) a frame disposed such that a perimeter rearward face thereof is in opposed facing relation with said ice-forming surface, wherein said frame is movable axially in the forward and rearward directions relative to said ice-forming surface; and(ii) an inflatable peripheral seal disposed between said rearward face of said frame and said ice-forming surface, wherein, when at a rearward position thereof, said frame, said inflatable peripheral seal and said ice-forming surface create a mold for forming said ice block therein.

32. The ice-forming method of claim 31, further comprising applying a specified force which tends to drive said frame in said forward direction, wherein said force is applied at a predetermined sequence of locations on a perimeter of said frame, to break a bond between said ice block and said ice-forming surface.

33. The ice-forming method of any one of claims 31 or 32, wherein said axial movement of said frame is controlled by a combination of (i) independently operating one or more actuators attached to respective locations around a perimeter of said frame, and (ii) inflating and deflating said inflatable peripheral seal.

34. The ice-forming method of any one of claims 31-33, wherein said specified force is applied by (i) inflating said inflatable peripheral seal to a predetermined internal pressure, and (ii) selectively operating said one or more actuators, according to said predetermined sequence of locations.

35. An ice-harvesting stack for an ice-making system, comprising: a frame disposed such that a perimeter rearward face thereof is in opposed facing relation with said ice-forming surface, wherein said frame is movable axially in the forward and rearward directions relative to said ice-forming surface; and an inflatable peripheral seal disposed between said rearward face of said frame and said ice-forming surface, wherein, when at a rearward position thereof, said frame, said inflatable peripheral seal and said ice-forming surface create a mold for forming of an ice block therein.

36. The ice-harvesting stack of claim 35, wherein said ice-forming surface defines a forward surface of an ice-making portion which comprises: an evaporator having a forward face; an elastomeric pad disposed over said forward face; a thin planar sheet disposed over a forward surface of said elastomeric pad; and a polymeric film disposed over a forward surface of said sheet, wherein a forward surface of said polymeric film defines an ice-forming surface for forming an ice block thereon.

37. The ice-harvesting stack of claim 36, wherein said ice-forming surface comprises one or more openings configured to release pressurized fluid between said ice-forming surface and said ice block formed thereon.

38. The ice-harvesting stack of claim 37, wherein said pressurized fluid applies a compressive force which causes a plurality of regions of said ice-forming surface and said sheet to deflect in a rearward direction against said elastomeric pad, thereby breaking a bond and separating between said ice-forming surface and said ice block formed thereon.

39. The ice-harvesting stack of any one of claims 35-38, wherein said iceharvesting stack is configured to apply a specified force which tends to drive said frame in a forward direction relative to said ice-forming surface, wherein said force is applied at a predetermined sequence of locations on a perimeter of said frame, to break a bond between said ice block and said ice-forming surface.

40. The ice-harvesting stack of any one of claims 35-39, wherein said axial movement of said frame is controlled by a combination of (i) independently operating one or more actuators attached to respective locations around a perimeter of said frame, and (ii) inflating and deflating said inflatable peripheral seal.

41. The ice-harvesting stack of any one of claims 35-40, wherein said specified force is applied by (i) inflating said inflatable peripheral seal to a predetermined internal pressure, and (ii) selectively operating said one or more actuators, according to said predetermined sequence of locations.

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