US3717009A

US3717009A - Refrigeration evaporator assembly

Info

Publication number: US3717009A
Application number: US00137405A
Authority: US
Inventors: M Butts
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1971-04-26
Filing date: 1971-04-26
Publication date: 1973-02-20
Anticipated expiration: 1990-02-20
Also published as: IT952617B; NO131363B; FR2134475B1; DE2220522A1; FR2134475A1; BR7202126D0; AU4060872A; GB1327723A; NO131363C; AU462432B2; CA955413A

Abstract

This invention relates to integral sheet metal refrigerator evaporator assemblies of the roll-forged type in final form having one section extending in a complete rectangular loop enclosing the freezing compartment and a depending plate section located in the above-freezing compartment. As an intermediate product a pair of evaporator assemblies are formed of two superposed planar sheets forming a composite panel having two Lshaped patterns of stop-weld material interposed between the sheets arranged in invertedly nested fashion for subsequent lancing from the panel with a minimum of scrap material.

Description

111 3,717,009 1 Feb. 20, 1973 United States Patent Butts [54] REFRIGERATION EVAPORATOR Primary Examiner-Meyer Perlin ASSEMBLY Attorney-William S. Pettigrew, Frederick M. Ritchie and Edward P. Barthel [75] Inventor: Mervin R. Butts, West Milton, Ohio [73] Assignee: General Motors Corporation,

Detroit, Mich.

ABSTRACT This invention relates to integral sheet metal refrigerator evaporator assemblies of the roll-forged type in final form having one section extending in a complete rectangular loop enclosing the freezing compartment [22] Filed: April 26, 1971 and a depending plate section located in the abovefreezing compartment. As an intermediate product a pair of evaporator assemblies are formed of .two superposed planar sheets forrning a composite panel having two L-shaped patterns of stop-weld material interposed between the sheets arranged in invertedly nested fashion for subsequent lancing from the'panel with aminimum of scrap material.

i m WW0 N m n m M .m A uh P ""5 C S WW2 m E W r M 5 u 0 mm" m T 4 an" e S 7 n h D 3 a" 1 mmm R m mme 0 t N 1 m U w m P Sun A UIF 1]] .l 1 2100 6 2 555 5 [Ii 2,795,117 6/1957 Herndon 2,966,781 1/1961 Schacfcr.................................62/523 3 Claims, 10 Drawing Figures PAIENTEDF'EBZOIW 3.717; 009 siim 1 or 2 INVENTOR.

BY Mervin f3 buzts W/fiw ATTORNEY PATENTEDFEBZOIQB. 3.717.009

SHEET 20F 2 I'N VENTOR.

BY Merw'nffuzfs wad/M ATTORNEY REFRIGERATION EVAPORATOR ASSEMBLY This invention relates to refrigeration evaporators of the roll-forged type and more particularly to an intermediate composite panel product for manufacturing a pair of integral evaporator assemblies.

In the prior art it has been proposed to manufacture integral plate-type evaporators for two-compartment refrigerators having a freezing compartment for storing frozen foods and an above-freezing compartment for the storage of fresh food vertically spaced therefrom. The prior art is exemplified by U. S. Pat. No. 2,795,113 issued June ll, 1957 to C. H. Wirtz, and U. S. Pat. No. 2,986,901 issued June 6, l96l, to E. F. Hubacker. Such prior art evaporators propose a box-shaped section bent to form a plurality of sides defining a freezer compartment and a plate section depending from the first section for refrigerating the above-freezing food storage compartment of the refrigerator. These unitary plate-type evaporators are formed from two superposed plan'ar sheets having interconnected refrigerant flow passages formed therein by suitable patterns of stop-weld or weld preventing material and thus eliminate the need for a plurality of separate connecting tubes and their attendant expensive heliarc welded connections.

It is an object of this invention to provide for the economical manufacture of integral plate-type evaporators by fabricating two substantially identical planar blank evaporator assemblies in nested inverted fashion whereby the pair of evaporator assemblies may be lanced from a single rectangular roll-forged composite panel with a minimum of scrap material.

Another object of this invention is to provide an improved intermediate product for the manufacture of integral evaporator freezer and refrigerator plate-type heat exchanger assemblies formed from two superposed planar sheets having a pair of L-shaped patterns of weld-preventing or stop-weld material interposed between the sheets wherein the patterns are arranged in reverse conformity such that each assembly has two spaced evaporator sections joined together by an integrally formed neck portion whereby they may be lanced from a single rectangular roll-forged panel with a minimum of scrap material.

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

In the drawings:

FIG. 1 is a fragmentary perspective view largely schematic showing the invention applied to a modern refrigerator;

FIG. 2 is a plan view of a pair of evaporating assemblies shown in FIG. 1 in nested condition before the blanking and forming thereof;

FIG. 3 is a plan view of one of the single evaporating assemblies shown in FIG. 1 in the inflated and lanced condition with the expanded refrigerant passages indicated thereon but before the evaporator sections have been bent into final shape;

FIG. 4 is a development plan view of an evaporator assembly indicating the integral securing means and fold lines thereof before the evaporator sections have been bent into final shape;

FIG. 5 is a front elevational view showing the relationship of the evaporators after installation into the refrigerator;

FIG. 6 is a view taken on line 66 of FIG. 4;

FIG. 7 is a view taken on line 7-7 of FIG. 4;

FIG. 8 is a view taken on line 8-8 of FIG. 4;

FIG. 9 is a view taken on line 9-9 of FIG. 5 and;

FIG. 10 is a fragmentary sectional view taken substantially on line 10-10 of FIG. 3.

Referring now to FIG. 1 of the drawings, wherein a preferred embodiment of the invention has been shown, reference numeral 10 generally designates a portion of a conventional refrigerator cabinet having an insulated frozen food storage compartment 12 in the upper portion thereof, an insulated but relatively higher temperature fresh food storage compartment 14 in the mid portion, and an uninsulated machinery compartment (not shown), arranged in the lower portion. In order to simplify the disclosure no door has been shown whereas preferably two doors would be provided for closing the openings to the compartments in accordance with standard practice. An integral platetype evaporator assembly is shown in development form at 1 6 in FIG. 4 and includes blank section and plate section 22. A formed rectangular loop portion 18 provides a box-shaped evaporator freezer for refrigerating the frozen food storage compartment 12 and depending evaporator plate section 22 is provided for refrigerating the above freezing compartment 14 in which the unfrozen foods are adapted to be stored.

A refrigerant liquifying system comprising a motorcompressor unit 24 and a condenser 26, diagrammatically illustrated, are mounted in the machinery compartment and serve to supply liquid refrigerant through a restrictor or capillary tube 28 connected to the outlet of the condenser.

The capillary tube 28 extends within suction line 30 to a combined entrance and exit 52 (FIG. 3) of the rectangular loop evaporator freezer 18. The details of one such combined entrance and exit arrangement is shown in U.S. Pat. No. 2,979,922 the disclosure of which is incorporated by reference herein.

A thermostatically operated switch 32 which includes a bulb 34 arranged in contact with thelower edge of the evaporation section 22 is used for starting and stopping the motor compressor unit 24 in response to refrigeration requirements. The switch 32 is of the type which is adapted to close the circuit to the motor compressor unit when the temperature of the bulb is a few degrees above the melting temperature of the frost which may form on the evaporation section 22 during the On cycle and is adapted to open the circuit when the temperature of the bulb approaches 0 fahrenheit. The relative size of the evaporator sections and the arrangement of the passages therein are such as to provide for automatic defrosting of the evaporator section 18.

The pair of

identical evaporator assemblies

16 and 16 are fabricated from two superposed planar sheets forming a composite panel indicated at 35 in FIG. 2, having a pattern of weld preventing or stop weld material interposed between the sheets in a manner shown generally in the Wirtz U.S. Pat. No. 2,795,113.

As

assemblies

16 and 16 are identical only assembly 16 is shown complete in development in FIG. 4. The

blank section is bent in rounded curves to form the rectangular loop portion 18 by means of the transversely extending substantially parallel fold areas A, B, C, D to provide a first side panel 36, a top panel 37, a second side panel 38 and a bottom panel 39 serially arranged in the order named. The panels 36-39 are bent at right angles to each other to form freezer surfaces for the top and bottom and sides of the below-freezing compartment 12 while the depending section 22 extends into the above freezing compartment 14. The rectangular loop evaporator portion 18 is connected to the plate evaporator section 22 by an integral web or neck portion 42, containing refrigerant passages connecting with the plate section 22 and spaced parallel and adjacent the rear wall of the above-freezing compartment 14. The capillary tube 28, connected to the outlet of the condenser 26, extends within the suction line 30 to the combined entrance and exit 52 of the rectangular loop portion 18. This combined entrance and exit extends through a restricted passage 54 in the loop portion 18 while the suctionline 30 fits into and connects with a much larger passage 56 having a side entrance 58.

Referring now to FIG. 3 which shows a plan view of the lanced evaporator assembly 16 after the internal passages have been dilated, it will be seen that the restricted portion 54 connects directly with a passage 60 extending to an entrance 62 at the lower right-hand corner of the blank evaporator section 20. The blank section 20 is provided with the waffle pattern of refrigerant passages substantially throughout its entire area and has the entrance 62 on one side and connecting with passage 60 and exit 64 connecting with a passage 66 extending parallel to the longitudinal edge 67 of blank section 20 through the neck portion 42 to the plate evaporator section 22. The plate evaporator section 22 may be provided with a combination of a waffle-type of passage section 68 and a serpentine passage 69 as shown or exclusively with either type of passage as desired. The refrigerant flows from the passage 69 through the passage 70 in the neck portion 42 -to the passage72 extending through the blank section 20 which there connects the refrigerant passage 58 connecting with the side of the passage 56. and the suction line 30 for return to the motor compressor unit 24.

As seen in FIG. 2 a pair of complete evaporators are preferably made in flat form from a pair of rectangular ,with stop-weld material to provide a composite homogeneous member.

In the present invention two generally L-shaped patterns of stop-weld, similar to the pattern of FIG. 3, are

applied to the surface of one of the

sheets

76 or 78. An inflation pass in the form of a band or stripe of stopweld material is applied to one surface of one of the sheets in the marginal area between the assemblies l6, 16 of the composite panel 35 as indicated by thepass 82. The inflation pass 82 extends to the upper longitudinal edge 67' of composite panel 35 and this unwelded portion has a needle inserted and the unwelded stopweld pattern of both integral evaporator assemblies 16 and 16' are thereafter inflated by means of fluid pressure entering both the combined entrance and exits 52 and 52'.

Each

evaporator assembly

16, 16 is then lanced out I by trimming to remove the marginal areas such that each

assembly

16, 16 appears as shown in FIG. 4. Thus the composite rectangular panel 35 contains two interconnected whole patterns of separation material each arranged in an L-shape configuration. The L-shaped patterns are oriented in nested fashion such that the evaporator assemblies have their blank sections 20, 20' extending longitudinally in offset manner resulting in, for example, the plate section 22 of assembly 16 being positioned in substantially longitudinal alignment with blank 20 and adjacent to the first side panel 36' of assembly 20'. As each evaporator assembly is formed with its plate section 22 and its associated neck portion 42 having a combined transverse dimension slightly greater than the transverse dimension of its blank section 20 the assemblies interfit in reverse conformity enabling the assemblies to be lanced from the compositepanel 35 with a minimum of scrap material. As the amount of scrap material is a critical factor in equating the cost of an integral evaporator assembly with that of separately formed evaporators applicants achievement of minimizing the amount of waste panel material has resulted in a practical low cost integral evaporator assembly.

Further included in the L-shaped evaporator assemblies are a plurality of recesses 92 and openings 94 cut or stamped around the periphery thereof. Specifically,

recesses 92 and openings 94 are cut in the flanges 9698 located along the front edge of the evaporator blank 20. These recesses and slots may be formed by any suitable method as by a punch press operation and they provide means whereby thenew and improved evaporator assembly may be assembled into its complete rectangular loop 18 shown in FIG. 5 by bending along the transverse fold areas A, B, C and D. The flanges 96-99 are shown tumed-out as seen in FIG. 7 to provideouter flanges of the formed freezer evaporator loop 18 which may be used for affixing the evaporator directly to a refrigerator liner side wall (not shown) as by means of a plurality of rivets extending through the openings 94 on a liner front wall portion and the evaporator loop 18. The front flange .96-99 of the freezer evaporator 18 are preferably positioned rear? wardly from the front edge of the liner so that the evaporator plus the freezer metallic rear wall, shown at 100 in FIG. 9, cooperate to form the rear, top, bottom and'side walls of a freezer compartment 12 having an access opening at the front thereof closed by means of a door (not shown). a

As seen in FIG. 8 the side wall panel 36 includes a step-up to a laterally extending narrow flange section 101 that overlies the flange 102 of bottom panel 39 and is secured thereto by any suitable means, such as screws 103 (FIG. 1) extending through apertures 104. The connecting entrance passage 52 located in plate 105 connects with the capillary tube 28 located adjacent the upper right-hand corner of side panel 36.

The freezer evaporator rectangular loop 18 is connected to the refrigerator evaporator plate section 22 by integral neck portion 42 interconnecting these parts at the rear edge of the bottom panel 39 of the freezer evaporator 18 with refrigerant flow developed

passageways

65 and 70 to eliminate separate connecting tubes. This integral arrangement provides an evaporator assembly with greater structural strength and, at the same time, attains a more complete utilization of the roll-forged, lanced and folded technique. As seen in FIG. 4 the portion of free edge 67 of bottom panel 39 has an intermediate recessed edge portion defined by notches 106, 108 which are lanced out of bottom panel 39 on either side of neck portion 42 such that the neck portion 42 is substantially centered on the transverse centerline of the bottom panel. This allows the neck portion to be bent into a smooth reverse curve as seen in FIG. 9. Thus, the evaporator plate section 22 can be located inwardly from and parallel to the rear wall 100 of the freezer and spaced forwardly therefrom such that evaporator plate 22 is positioned adjacent the inner back wall of the refrigerator or above-freezing compartment 14 whereby kinking of the

passageways

65 and 70 is eliminated. It will be noted that while the refrigerant passageways are shown in FIG. as formed in both

sheets

76 and 78 it will be appreciated that the passageways could be formed primarily in only one sheet without departing from the scope of the present invention as shown in US. Pat. No. 2,773,300 issued Jan. 15, 1957 to J. S. Palmer. The Palmer patent also disclosed various means for securing the sheets such as a copper brazing process which could be substituted for applicants preferred roll-forged securing means.

In this regard the term inverted is used in the sense i that one evaporator assembly is positioned on the panel 35 as if it were rotated 180 to nest or interfit in reverse conformity with a second assembly. Thus, after the assemblies are lanced from the panel either assembly may be rotated or turned end-for-end within a common plane to provide two substantially identical evaporator assemblies.

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

What is claimed is:

1. In combination a composite roll-forged rectangular panel formed of two superposed planar sheets having a pattern of stop-weld material between the sheets to form a pair of substantially identical integral evaporator assemblies in planar development form such that each of said assemblies may be formed for ultimate use in cooling both a freezer compartment and an above-freezing compartment of a refrigerator, each said evaporator assembly having a generally L-shaped configuration defining a freezer compartment evaporator blank section and an above-freezing compartment refrigerator evaporator plate section joined together by an integrally formed neck portion, the pattern of stopweld material forming a refrigerant circuit in the sections of each said evaporator assembly and which are connected together by refrigerant passages in their associated neck portion, each said evaporator assembly having its freezer evaporator blank section extending longitudinally on said composite panel presenting a first side panel, a top panel, a second side panel and a bottom panel foldably connected by substantially parallel transversely extending fold areas and serially arranged in the order named, each said refrigerator evaporator plate section joined by its neck portion along one longitudinal side edge of its associated bottom panel,each said evaporator plate section and its associated neck portion having a combined transverse dimension substantially equal to the transverse dimension of the freezer compartment evaporator blank section, said evaporator assemblies oriented on said composite panel in offset inverted fashion such that the refrigerator freezer compartment evaporator plate section of each evaporator assembly is positioned in longitudinal alignment with and adjacent to the first side panel of the other evaporator assembly whereby said pair of evaporator assemblies interfit in reverse conformity enabling said assemblies to be lanced from said composite panel with a minimum of scrap material located intermediate the adjacent edges upon the lancing of said evaporator assemblies.

2. In combination a composite roll-forged rectangular panel formed of two superposed planar sheets having a pattern of stop-weld material between the sheets to form a pair of first and second substantially identical integral evaporator assemblies in planar development form for ultimate use in a refrigerator, each said evaporator assembly having a generally L-shaped configuration defining a freezer evaporator blank section and a refrigerator evaporator plate section joined together by an integrally formed neck portion, the pattern of stop-weld material forming a refrigerant circuit in the sections of each said evaporator assembly and which are connected together by refrigerant passages in their associated neck portion, each said evaporator assembly having its freezer evaporator blank section extending longitudinally on said composite panel representing a first side panel, a top panel, a second side panel and a bottom panel foldably connected by substantially parallel transversely extending fold areas and serially arranged in the order named, each said refrigerator evaporator plate section joined by its neck portion along one longitudinal side edge of its associated bottom panel, each said refrigerator evaporator plate section and its associated neck portion having a combined transverse dimension slightly larger than the transverse dimension of the freezer evaporator blank section whereby the coextensive opposed portions of the blank sections are separated by an intermediate marginal area, each said evaporator assembly having a combined inlet and outlet passage located at the transverse edge of each first side panel, said evaporator assemblies oriented on said composite panel in offset inverted fashion such that the refrigerator evaporator plate section of said first evaporator assembly is positioned in longitudinal alignment with and adjacent to the first side panel of said second evaporator assembly whereby said first and second evaporator assemblies interfit in reverse conformity enabling said assemblies to be lanced from said composite panel with a minimum of scrap material, a single inflated passageway provided by the stop-weld material extending in a transverse direction from one longitudinal edge of said composite panel and located between the first side panel of said second evaporator blank section and the evaporator plate section of said first evaporator assembly, said passageway having a tap connecting with the combined inlet and outlet of said second evaporator blank section, said single passageway thence having a 90 turn to extend longitudinally in said intermediate marginal area to a position beyond the first side panel of said first evaporator assembly, said passageway thence having a U-shaped turn connecting with the combined inlet and outlet of said first evaporator assembly whereby said first and second evaporator assembly refrigerant circuits are inflated by said single passageway.

3. In a household refrigerator having a freezer compartment and above freezing compartment, means for' the operation of said means for supplying liquid refrigerant to said sections, the improvement wherein said rectangular loop section is formed from a blank section presenting a first side panel, a top panel, a second side panel and a bottom panel serially arranged in the order named and foldably connected by fold areas forming three comer junctures of said rectangular loop, a vertical back wall closing the rear open end of said rectangular loop, said bottom panel having a rearwardly facing horizontal free edge, said free edge having an intermediate recessed edge portion centered on the transverse centerline of said bottom panel, a relatively narrow neck portion extending from said recessed edge integrally connecting said depending plate section with said bottom panel, inflated refrigerant passageways formed in said neck portion interconnecting said evaporator sections, said neck portion being bent into a smooth reverse curve such that said plate section is arranged in parallel with the rear wall of said freezing compartment and spaced forwardly therefrom for location in said above freezing compartment whereby kinking of said passageways in said neck portion is eliminated.

Claims

1. In combination a composite roll-forged rectangular panel formed of two superposed planar sheets having a pattern of stop-weld material between the sheets to form a pair of substantially identical integral evaporator assemblies in planar development form such that each of said assemblies may be formed for ultimate use in cooling both a freezer compartment and an above-freezing compartment of a refrigerator, each said evaporator assembly having a generally L-shaped configuration defining a freezer compartment evaporator blank section and an above-freezing compartment refrigerator evaporator plate section joined together by an integrally formed neck portion, the pattern of stop-weld material forming a refrigerant circuit in the sections of each said evaporator assembly and which are connected together by refrigerant passages in their associated neck portion, each said evaporator assembly having its freezer evaporator blank section extending longitudinally on said composite panel presenting a first side panel, a top panel, a second side panel and a bottom panel foldably connected by substantially parallel transversely extending fold areas and serially arranged in the order named, each said refrigerator evaporator plate section joined by its neck portion along one longitudinal side edge of its associated bottom panel, each said evaporator plate section and its associated neck portion having a combined transverse dimension substantially equal to the transverse dimension of the freezer compartment evaporator blank section, said evaporator assemblies oriented on said composite panel in offset inverted fashion such that the refrigerator freezer compartment evaporator plate section of each evaporator assembly is positioned in longitudinal alignment with and adjacent to the first side panel of the other evaporator assembly whereby said pair of evaporator assemblies interfit in reverse conformity enabling said assemblies to be lanced from said composite panel with a minimum of scrap material located intermediate the adjacent edges upon the lancing of said evaporator assemblies.

1. In combination a composite roll-forged rectangular panel formed of two superposed planar sheets having a pattern of stopweld material between the sheets to form a pair of substantially identical integral evaporator assemblies in planar development form such that each of said assemblies may be formed for ultimate use in cooling both a freezer compartment and an above-freezing compartment of a refrigerator, each said evaporator assembly having a generally L-shaped configuration defining a freezer compartment evaporator blank section and an above-freezing compartment refrigerator evaporator plate section joined together by an integrally formed neck portion, the pattern of stop-weld material forming a refrigerant circuit in the sections of each said evaporator assembly and which are connected together by refrigerant passages in their associated neck portion, each said evaporator assembly having its freezer evaporator blank section extending longitudinally on said composite panel presenting a first side panel, a top panel, a second side panel and a bottom panel foldably connected by substantially parallel transversely extending fold areas and serially arranged in the order named, each said refrigerator evaporator plate section joined by its neck portion along one longitudinal side edge of its associated bottom panel, each said evaporator plate section and its associated neck portion having a combined transverse dimension substantially equal to the transverse dimension of the freezer compartment evaporator blank section, said evaporator assemblies oriented on said composite panel in offset inverted fashion such that the refrigerator freezer compartment evaporator plate section of each evaporator assembly is positioned in longitudinal alignment with and adjacent to the first side panel of the other evaporator assembly whereby said pair of evaporator assemblies interfit in reverse conformity enabling said assemblies to be lanced from said composite panel with a minimum of scrap material located intermediate the adjacent edges upon the lancing of said evaporator assemblies.

2. In combination a composite roll-forged rectangular panel formed of two superposed planar sheets having a pattern of stop-weld material between the sheets to form a pair of first and second substantially identical integral evaporator assemblies in planar development form for ultimate use in a refrigerator, each said evaporator assembly having a generally L-shaped configuration defining a freezer evaporator blank section and a refrigerator evaporator plate section joined together by an integrally formed neck portion, the pattern of stop-weld material forming a refrigerant circuit in the sections of each said evaporator assembly and which are connected together by refrigerant passages in their associated neck portion, each said evaporator assembly having its freezer evaporator blank section extending longitudinally on said composite panel representing a first side panel, a top panel, a second side panel and a bottom panel foldably connected by substantially parallel transversely extending fold areas and serially arrangeD in the order named, each said refrigerator evaporator plate section joined by its neck portion along one longitudinal side edge of its associated bottom panel, each said refrigerator evaporator plate section and its associated neck portion having a combined transverse dimension slightly larger than the transverse dimension of the freezer evaporator blank section whereby the coextensive opposed portions of the blank sections are separated by an intermediate marginal area, each said evaporator assembly having a combined inlet and outlet passage located at the transverse edge of each first side panel, said evaporator assemblies oriented on said composite panel in offset inverted fashion such that the refrigerator evaporator plate section of said first evaporator assembly is positioned in longitudinal alignment with and adjacent to the first side panel of said second evaporator assembly whereby said first and second evaporator assemblies interfit in reverse conformity enabling said assemblies to be lanced from said composite panel with a minimum of scrap material, a single inflated passageway provided by the stop-weld material extending in a transverse direction from one longitudinal edge of said composite panel and located between the first side panel of said second evaporator blank section and the evaporator plate section of said first evaporator assembly, said passageway having a tap connecting with the combined inlet and outlet of said second evaporator blank section, said single passageway thence having a 90* turn to extend longitudinally in said intermediate marginal area to a position beyond the first side panel of said first evaporator assembly, said passageway thence having a U-shaped turn connecting with the combined inlet and outlet of said first evaporator assembly whereby said first and second evaporator assembly refrigerant circuits are inflated by said single passageway.