US3599442A

US3599442A - Unitary fan evaporator assembly

Info

Publication number: US3599442A
Application number: US859779A
Authority: US
Inventors: Robert S Hanson
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1969-09-22
Filing date: 1969-09-22
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17

Abstract

In the preferred form, a refrigerator cabinet is provided with a sheet metal outer shell and a plastic inner liner with polyurethane foam insulation in between. The interior of the inner liner is divided into an upper freezing compartment and a lower above freezing compartment by a sheet metal wall having a lower portion in the rear and a higher portion in the front. Above this lower portion there is provided cast foam insulation beneath an evaporator compartment having inlets extending to it from the front of the upper freezing compartment and from the lower compartment through the portion of the sheet metal wall between the lower and higher portions. Resting upon the cast foam insulation is a large drain pan which extends beneath and supports a tubular horizontally extending evaporator having upright fins extending from the front to the rear. The drain pan also has brackets and a vibration-absorbing mounting for supporting the fan motor at the rear of the evaporator having a drive shaft extending rearwardly through the rear wall of the inner liner where it is provided with a side inlet centrifugal fan which draws the air through the inlets and the evaporator and discharges it into an upwardly extending duct extending to the upper compartment and a downwardly extending duct extending to the lower compartment, both of which are housed in the plastic foam insulation between the rear walls of the inner liner and outer shell.

Description

United States Patent Primary ExaminerWilliam J. Wye Att0rneys-William S. Pettigrew, Frederick M. Ritchie and Edward P. Barthel ABSTRACT: In the preferred form, a. refrigerator cabinet is provided with a sheet metal outer shell and a plastic inner liner with polyurethane foam insulation in between. The interior of the inner liner is divided into anupper freezing compartment and a lower above freezing compartment by a sheet metal wall having a lower portion in the rear and a higher portion in the front. Above this lower portion there is provided cast foam insulation beneath an evaporator compartment having inlets extending to it from the front of the upper freezing compartment and from the lower compartment through the portion of the sheet metal wall between the lower and higher portions. Resting upon the cast foam insulation is a large drain pan which extends beneath and supports a tubular horizontally extending evaporator having upright fins extending from the front to the rear. The drain pan also has brackets and a vibration-absorb ing mounting for supporting the fan motor at the rear of the evaporator having a drive shaft extending rearwardly through the rear wall of the inner liner where it is provided with a side inlet centrifugal fan which draws the air through the inlets and the evaporator and discharges it into an upwardly extending duct extending to the upper compartment and a downwardly extending duct extending to the lower compartment, both of which are housed in the plastic foam insulation between the rear walls of the inner liner and outer shell.

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ATTORNEY UNITARY FAN EVAPORATOR ASSEMBLY This invention relates to multiple-compartment frost-free.

refrigerators.

Frost-free refrigerators with effective foam insulation are very desirable. However, the sales of such refrigerators have been restricted by higher costs.

It is an object of this invention to provide a unitary refrigerating assembly for frost-free refrigeration which can be economically mounted within the inner liner and which can be economically manufactured and tested as a separate unit.

It is also another object of the invention to provide a refrigerating unit within the inner liner which will be compact which will make use of the least desirable space within the refrigerator.

It is another object of this invention to provide a refrigerator with upper and lower compartments and a unitary refrigerating unit and fan in a dividing wall between the compartments which cooperate with distributing ducts in the rear wall of the cabinet.

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

In the drawings:

FIG. 1 is a front view partly in section of a frost-free refrigerator embodying one form of my invention;

FIG. 2 is a fragmentary horizontal sectional view taken through the dividing wall along the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary vertical sectional view including the dividing wall taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a top view of the assembled cast insulation pieces partially shown in FIG. 3; and

FIG. 5 is an exploded perspective view of the cast insulation pieces and the refrigerating unit shown in FIGS. 2 to 4.

Referring now to the drawings and more particularly to FIGS. 1 and 2, there is illustrated a refrigerator cabinet including an outer sheet metal shell 120 having inturned front flanges 122 extending around the front opening of the shell. Within the outer shell 120 is a one-piece plastic inner liner 124 having a bottom wall provided with a front lower section 126 and a rear higher section 128 over the motor compressor 130 and the condenser 132. The inner liner and outer shell include spaced

rear walls

134 and 136. Plastic foam insulation 138 containing an insulating gas is provided between the inner liner 124 and the outer shell 120 which reinforces both the inner liner and outer shell and increases the rigidity of the structure so that separately the inner liner and outer shell need not be rigid.

According to my invention, within the inner liner 124 I provide an improved form of horizontally extending dividing means 140 forming an upper subcompartment 142 to be maintained at below freezing temperatures between about 0 and F. and a lower above freezing compartment 144 to be maintained at above freezing temperatures of about 36 F. This lower compartment 144 may be provided with two or more horizontal shelves 145.

The top wall of the lower subcompartment 144 is provided by a sheet metal wall 146 forming the bottom of the dividing means 140. The wall 146 includes a higher portion 148 at the front and a lower portion 450 at the rear with a slanted connecting section 152 in between the front and rear portions provided with air inlets 151 to the evaporator compartment 153 above. This wall 146 preferably is supported at the rear by plastic supports (not shown) composed of glass fibers and high temperature thermoset plastics such as polyester or phenolformaldehyde resin. The wall is supported at the front by a transverse metal crossmember 156 extending between the inturned flanges 122 ofthe outer shell 120.

Resting upon the lower portion 450 is a cast foam insulation piece 158 supporting a unitary removable cooling assembly 451 in which the drain pan 12 serves as a supporting frame and extends beneath substantially the entire unit. It is curved upwardly at the edges and at the sides and at the rear it is provided with upwardly extending side and rear walls 160,162. Within the rear comers are L-shaped supporting brackets 164 and at the center rear there is provided a pair of Z-shaped supporting brackets 166 to which is connected a U-shaped fan motor bracket 167 and a transverse end motor bracket 179 extending across the open portion of the U-shape.

Connected to the L-shpaed brackets 164 by threaded fasteners are the end plates 33 of a refrigerant evaporator 24 having horizontal pieces of tubing extending in serpentine fashion through the cross fins 32 extending from front to rear. This refrigerant evaporator 24 is generally rectangular on all sides with the end portion being generally nearly squareshaped. As shown, the fins 32 are arranged in a front and a rear section with a cut out extending up from the bottom in between the two sections for receiving a transversely extending radiant heat type of defroster heater 506. The ends of this radiant heat defroster heater are supported by spring brackets 37 riveted to and protruding outwardly from the end plates 33. This central location for the radiant heater assures sufficient downwardly directed radiant heat to melt any ice in the drain pan 12 beneath and assures substantially direct radiant emission to all parts of the evaporator within a relatively close range. To prevent the defrost water from dripping onto the radiant heater 506 the tops of the openings in the fins are provided with narrow annular oppositely extending flanges 38 which form sort of a cover over the radiant heater.

The outlet of the evaporator 24 is connected to a receiver 27 extending diagonally upwardly in front of the evaporator above the front of the drain pan 12. The upper end of this receiver 27 is connected by the Lshaped tubing 28 to the stem of a T connection 6. The left half of the straight through portion of the T connection 6 connects to the inlet 23 of the evaporator 24 beneath the receiver 27. A capillary liquid supply tube 19 has its discharge end extending through the straight through portion of the T connection and the necked in portion of the inlet tube 23 for discharging liquid refrigerant thereto. This capillary tube 19 extends through the straight portion of the T connection 6 and through the coiled portion 22 of the suction line 20 to the machinery compartment below. The capillary tube 19 emerges from the suction line 20 in the machinery compartment 168 beneath the cabinet. The suction line 20 is provided with a T connection connecting with the inlet tube 170 of the sealed motor compressor unit 130. This provides a simple single entry arrangement in which the concentric capillary supply tube 19' and the suction conduit 20 can be readily passed through a double grommet 172 located in the rear wall for connection with the condensing system beneath the cabinet.

The sealed motor compressor unit 1311 draws refrigerant from the inlet tube 170 and discharges the compressed refrigerant into a condenser 132 from which liquid refrigerant flows through a loop of tubing 174 provided inside the inturned flanges 122 around the door opening of the cabinet. The outlet end of this loop connects with a filter drier 176 connecting to the capillary supply tube 19. This loop of tubing 174 further disipates to the outer shell some of the heat of the liquid leaving the condenser 132 to provide additional cooling of the warm liquid. It also contacts brackets supporting the crossmember 156 and serves the purpose of preventing sweating or moisture condensation on the cabinet shell adjacent the door openings.

The upper and

lower subcompartments

142 and 144 are closed by an upper door 178 and a lower door 180. The cooling assembly is made separate from the motor compressor condenser assembly and these are separately inserted into the cabinet with the combined suction conduit 21) and capillary tube 19 being passed through the grommet 172 and their ends connected to the inlet tube 170 and filter drier 176. The cooling assembly 451 also includes a fan motor 13 having concentric hubs at the ends of its axis which are held within vibration absorbing rubber rings 14 which are mounted in apertures in the fan motor supporting members 167 and 179. The fan motor has its drive shaft extending rearwardly and provided with a side inlet type centrifugal-type fan 91. The rear walls 162 are provided with a fan housing orifice 90 extending around the side opening of the fan in the vicinity of the peripheral blades of the fan 91. The fan 91 projects through an opening 182 in the plastic liner 124.

Located in the insulation of the rear wall is a plastic duct 74 including a central scroll section surrounding the fan 91 and a wide upwardly extending duct portion 184 extending up to an upper outlet 186 in the rear wall 134 of the plastic liner 124 through which the air from the fan is discharged into the upper subcompartment 142. The downwardly extending duct portion 188 extends to a smaller outlet 190 for the discharge of air into the lower compartment 144. These ducts and outlets are so proportioned to the size and heat leaks of the upper and

lower subcompartments

142 and 144 so that the upper subcompartment is maintained at the desired temperatures of between and F. and the lower subcompartment 144 is maintained at a temperature of about 36 F. The fan 91 draws air from the upper subcompartment 142 through the inlets 191 at the front of the plastic bottom wall 193 of the compartment 142 into the evaporator compartment 153. The evaporator 24 is insulated from the compartment 142 by a slab 195 of insulation located between the wall 193 and the evaporator- 24. Air is. also drawn from the lower subcompartment 144 vthrough the openings 151 into the evaporator compartment 153 from which the combined air is drawn through the evaporator 24 and discharged by the fan 91 through the scroll section of the duct 74 and the duct 188 and outlet 190 to the lower subcompartment 144. The cooling assembly also includes wiring 117 including a pair of

conductors

61 and 64 connecting with the fan motor 13 and

conductors

192 and 194 connecting with the

terminals

196 and 198 upon the ends of the radiant defrost heater tube 506. The conductor 194 connects to a defrost limiter thermostat 115 mounted in a bracket 116 on the right rear wall portion 162. The defrost limiter switch 115 connects to the conductor 221. All this wiring ex tends from the fooling assembly through the double grommet 172 in the rear wall to the remainder of the system in the machine compartment 168 below.

With this arrangement the entire unit supported by the drain pan 12 can be built and assembled and wired as a separate unit and then tested prior to its assembly into the cabinet. This makes the cabinet assembly much more convenient and less expensive and makes it possible to correct any defects and improper assembly before its assembly into the cabinet. This reduces delays in the cabinet assembly line due to rejections of parts in the refrigerating system and makes for a much more economical manufacture with improved qualities of workmanship.

The cast foam insulation piece 158 includes a supporting ledge 223 extending around a central aperture 225 beneath the drain pan 12. Extending above the ledge 223 is a front wall 227 containing three notches 229 forming air passages which are aligned with the three openings 151 in the sheet metal bottom wall 146. Also above the ledge 223 are the integral sidewalls 231 which insulate the walls 160 and the integral rear walls 233 which insulate the walls 162 and which are divided to provide an opening for the fan 91. The ledge also includes a notch 235 for the drain trough 237 (FIG. 3) which extends from the outlet in the bottom of the drain pan 12 rearwardly to the rear wall 134. A plastic bag 239 of polyethylene or other suitable plastic containing mineral wool or glass fibers is located in the large rectangular opening 225 beneath the drain pan 12 and the trough 237 to provide a form of insulation which will substantially obstruct transmission of moisture vapor to the bottom of the drain pan 12. The insulation piece 158 is also provided with a groove 241 for the refrigerant conduit and with groove 243 for the electrical conductors 117 extending through the corner ofthe right rear wall 233.

A second cast insulation piece 245 is provided between the front portion of the bottom member 193 of the below freezing compartment 142 and the uppermost portion 148 of the sheet metal wall 146. The rear portion overlaps the front wall 227 of the piece 158 to extend over the passages 229 therein. This front piece contains wide passages 247 between the supports 249 which conduct the air from the entrance 191 in the wall 193 to the evaporator chamber 153. The piece 245 keeps the air from the

compartments

142 and 144 separated until they reach the evaporator compartment 153. The

insulation pieces

158 and 245 may be cast of polystyrene beads or of polyurethane foam or any other suitable form of plastic foam insulation. These insulation pieces are light and easily handled and effectively guide the flow of air between the compartments 141 and 142 and the fan 91 so that restrictions to flow are minimized and the flow is substantially evenly distributed over the evaporator 451. The split rear walls 233 are wedge-shaped and thinner at the center so that they diverge away from the rear of the evaporator 24 as they approach the fan 91 to provide a flat triangular plenum chamber for the uniform drawing of the air from the rear face of the evaporator 24 by the fan 91.

While the embodiments of the invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

1 claim:

1. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a dividing means within said inner liner dividing said compartment into subcompartments wherein the improvement comprises a sheet member upon the bottom of said dividing means having a high portion and a low portion and an offset between said high and low portions, said dividing means having an insulated compartment above said low portion, a subassembly located in said insulated compartment in said dividing means above said low portion, said subassembly comprising a drain pan located in the lower portion of said insulated compartment and an evaporator supported on said drain pan adjacent said offset and a fan and fan motor supported on said drain pan on the opposite side of said evaporator from said offset, said dividing means having suction passage means extending from the subcompartment beneath said high portion through said offset to said insulated compartment and suction passage means extending from the subcompartment above said dividing means to said insulated compartment, and discharge passage means extending from said fan to said subcompartments.

2. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a laterally extending dividing means within said inner liner dividing said compartment into upper and lower subcompartments wherein the improvement comprises, a sheet member upon the bottom of said dividing means having a high portion adjacent the front of said cabinet and a low portion adjacent the rear of said cabinet and an offset between said high and low portions, said dividing means having an insulated compartment at the rear of said offset above said low portion, a subassembly located in said insulated compartment in said dividing means above said low portion comprising a drain pan located in the lower portion of said insulated compartment and an evaporator supported on said drain pan and a fan and fan motor supported on said drain pan on the opposite side of said evaporator from said offset, said dividing means having suction passage means extending from the upper and lower subcompartments to said insulated compartment between said offset and said evaporator, and discharge passage means extending from said fan to said upper and lower subcompartments.

3. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a sheet member within said inner liner separating the lower portion of said compartment from the space above, said sheet member having a high portion and a low portion and an offset between said high and low portions, an insulation piece supported upon said low portion ofsaid sheet member and having an interior cavity providing an insulated evaporator compartment above said low portion, a refrigerant evaporator located in said insulated evaporator compartment and supported upon said insulation piece, said evaporator being provided with an inlet side adjacent said offset and an outlet side on the opposite side of said offset, said insulation piece being provided with insulating walls upon the sides of said evaporator and being provided with inlet passage means between said offset and said inlet side of said evaporator and being provided with an outlet passage means in the wall on the outlet side of said evaporator, fan means located adjacent said outlet passage means for drawing air through said inlet passage means and said evaporator and said outlet passage means, and discharge passage means extending from said fan means to the lower portion of said compartment and to the space above.

4. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a sheet member within said inner liner separating the lower portion of said compartment from the space above, said sheet member having a high portion and a low portion and an offset between said high and low portions, a first insulation piece supported upon said low portion of said sheet member and having an interior cavity providing an insulated evaporator compartment above said low portion, a refrigerant evaporator located in said evaporator compartment and supported upon said insulation piece, said evaporator being provided with an inlet side adjacent said offset and an outlet side on the opposite side of said offset, said insulation piece being provided with insulating walls upon the sides of said evaporator and being provided with air inlet notches in said wall between said offset and said inlet side of said evaporator and being provided with air outlet passage means in the wall on the outlet side of said evaporator, a second insulation piece mounted on the high portion of said sheet member and extending over the wall of said first men tioned insulation piece between said offset and the inlet side of said evaporator and extending above said air inlet notches, said second insulation piece being provided with air passage means extending from the space above to said insulated evaporator compartment, said sheet member having air openings communicating with said notches in said first-mentioned insulation piece, fan means located adjacent said outlet passage means for drawing air through said air openings in said sheet member and said air inlet notches in said wall and said air passage means in said second insulation piece and said evaporator and said outlet passage means, and discharge passage means extending from said fan means to the lower portion of said compartment and to the space above.

5. A refrigerator including a cabinet having an outer shell and an inner linear enclosing a compartment, a sheet member within said inner liner separating the lower portion of said compartment from the space above, an insulation piece in the general shape of a rectangle with a central opening extending through its bottom and a supporting ledge extending alongside said opening, a drain pan in said opening supported upon said ledge, an evaporator in said opening supported upon said drain pan, said insulation piece having air inlet passage means on one side of said evaporator and air outlet passage means on the opposite side of said evaporator, air entrance means extending from said compartment to said air inlet passage means and discharge air passage means extending from said air outlet passage means to said compartment, fan means for circulating air through said air entrance means and said air inlet passage means and said insulation piece and said evaporator and said air outlet passage means, and a plastic bag containing a fibrous insulation material located within the opening in said insulation piece beneath said drain pan.

6. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a dividing means within said inner liner dividing said compartment into sub compartments wherein the improvement comprises a preas sembled refrigeration and defrost subassembly capable of being electrically tested prior to its assembly into the cabinet for location in said dividing means, said subassembly comprising a sheet metal drain pan having upwardly extending sidewalls and rear walls, a refrigerant evaporator extending over a major fportion of the drain pan and supported by the dram pan, a an motor and shaft supported upon said drain pan between said evaporator and said inner liner, said fan motor supported within the confines of said drain pan by means of a fan motor bracket secured to said rear walls, said inner liner being provided with an aperture located in substantial coaxial relation with said fan motor and shaft, said shaft extending through said aperture and being provided with a fan located at least partially between the inner liner and outer shell, duct means between said inner liner and outer shell extending from said fan to said subcompartments, said dividing means having passages extending from said subcompartments to the side of the evaporator opposite said fan motor, a defrost heater supported by said evaporator for removing frost from said evaporator, a defrost limiter switch mounted upon said drain pan, and wiring supported by said drain pan connecting to said fan motor and connecting said defrost heater and said limiter switch in series circuit.

Claims

3. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a sheet member within said inner liner separating the lower portion of said compartment from the space above, said sheet member having a high portion and a low portion and an offset between said high and low portions, an insulation piece supported upon said low portion of said sheet member and having an interior cavity providing an insulated evaporator compartment above said low portion, a refrigerant evaporator located in said insulated evaporator compartment and supported upon said insulation piece, said evaporator being provided with an inlet side adjacent said offset and an outlet side on the opposite side of said offset, said insulation piece being provided with insulating walls upon the sides of said evaporator and being provided with inlet passage means between said offset and said inlet side of said evaporator and being provided with an outlet passage means in the wall on the outlet side of said evaporator, fan means located adjacent said outlet passage means for drawing air through said inlet passage means and said evaporator and said outlet passage means, and discharge passage means extending from said fan means to the lower portion of said compartment and to the space above.

4. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a sheet member within said inner liner separating the lower portion of said compartment from the space above, said sheet member having a high portion and a low portion and an offset between said high and low portions, a first insulation piece supported upon said low portion of said sheet member and having an interior cavity providing an insulated evaporator compartment above said low portion, a refrigerant evaporator locatEd in said evaporator compartment and supported upon said insulation piece, said evaporator being provided with an inlet side adjacent said offset and an outlet side on the opposite side of said offset, said insulation piece being provided with insulating walls upon the sides of said evaporator and being provided with air inlet notches in said wall between said offset and said inlet side of said evaporator and being provided with air outlet passage means in the wall on the outlet side of said evaporator, a second insulation piece mounted on the high portion of said sheet member and extending over the wall of said first mentioned insulation piece between said offset and the inlet side of said evaporator and extending above said air inlet notches, said second insulation piece being provided with air passage means extending from the space above to said insulated evaporator compartment, said sheet member having air openings communicating with said notches in said first-mentioned insulation piece, fan means located adjacent said outlet passage means for drawing air through said air openings in said sheet member and said air inlet notches in said wall and said air passage means in said second insulation piece and said evaporator and said outlet passage means, and discharge passage means extending from said fan means to the lower portion of said compartment and to the space above.

6. A refrigerator including a cabinet having an outer shell and an inner liner enclosing a compartment, a dividing means within said inner liner dividing said compartment into subcompartments wherein the improvement comprises a preassembled refrigeration and defrost subassembly capable of being electrically tested prior to its assembly into the cabinet for location in said dividing means, said subassembly comprising a sheet metal drain pan having upwardly extending sidewalls and rear walls, a refrigerant evaporator extending over a major portion of the drain pan and supported by the drain pan, a fan motor and shaft supported upon said drain pan between said evaporator and said inner liner, said fan motor supported within the confines of said drain pan by means of a fan motor bracket secured to said rear walls, said inner liner being provided with an aperture located in substantial coaxial relation with said fan motor and shaft, said shaft extending through said aperture and being provided with a fan located at least partially between the inner liner and outer shell, duct means between said inner liner and outer shell extending from said fan to said subcompartments, said dividing means having passages extending from said subcompartments to the side of the evaporator opposite said fan motor, a defrost heater supported by said evaporator for removing frost from said evaporator, a defrost limiter switch mounted upon said drain pan, and wiring supported by said drain pan connecting to said fan motor and connecting said defrost heater and said limiter switch in series circuit.