IE73660B1

IE73660B1 - A method for manufacturing a refrigerator cabinet

Info

Publication number: IE73660B1
Application number: IE930124A
Authority: IE
Inventors: Paul S Power
Original assignee: Orrell Ltd
Priority date: 1993-02-22
Filing date: 1993-02-22
Publication date: 1997-06-18
Also published as: IE930124A1; GB9304101D0; GB2275327B; BE1005495A6; GB2275327A

Abstract

A refrigerator cabinet is manufactured by first forming panels into a desired shape for an inner liner. The liner is assembled to form a chest frame and a heat exchanger coil is wound around the frame. An outer cabinet body is formed around the chest frame and the cabinet thus formed is turned so that the open side of the cabinet is lowermost in a mould (27, 28). The cavity between the frame and outer cabinet is then filled with insulating foam via an inlet opening (29).

Description

“A method for manufacturing a refrigerator cabinets The invention relates to refrigerator cabinets and in particular to a method for manufacturing a refrigerated cabinet.

There are many known methods for manufacturing 5 refrigerator cabinets. A larger number of steps, however, are involved in the manufacturing process and for optimum manufacturing efficiency with lowest manufacturing costs, it is essential that the various manufacturing operations are optimised.

This invention is directed towards providing an improved method for manufacturing refrigerator cabinets in a cost efficient manner.

According to the invention there is provided a method for manufacturing a refrigerator cabinet comprising the steps of:forming panels into elements of an inner liner; .forming panels into elements of an outer cabinet body; some of the elements being flanged elements and some of the elements being flangeless elements; at least some of the flanged elements being formed by forming side edges on some of the panels, cutting away portion of the side flanges at a desired bending location, and bending the flanged panel about a bending formation to form a flanged element which is bent intermediate the ends thereof; at least some of the flangeless elements being formed by bending a flat panel at two spaced-apart locations -2siroultaneousiy to form an element of generally channel shape; assembling the inner liner; applying a coil around the outside of the liner to form a chest frame; applying an insulating and retaining tape over the coil; assembling outer cabinet body elements to the chest frame; turning the cabinet thus formed so that an open side of the cabinet is lowermost; lowering the open side of the cabinet onto an inner mould part; closing an outer mould part around the cabinet; injecting liquid plastic foam reactants into the cavity defined between the chest frame and the outer cabinet body; curing the foam so that the insulating foam fills the cavity between and bonds to the chest frame and outer cabinet; opening the mould; t removing the refrigerator cabinet from the mould; fitting a compressor, motor, evaporator and associated parts to the cabinet; testing the electrical circuitry; charging the refrigerant system with refrigerant; leak testing the refrigerant circuit; running the refrigerator cabinet for a prolonged period to ensure that a desired refrigeration temperature is achieved and maintained; and packing the refrigerator cabinet in preparation for dispatch.

In a particularly preferred embodiment of the invention the liquid foam reactants are injected into the cavity between the chest frame and outer cabinet body at the side of the cabinet opposite to the open side.

In one embodiment of the invention the method includes the step of applying a lid to the cabinet after filling of the cavity with insulating foam. The lid may, for example, comprise a single curved pane of transparent material and a frame surrounding the pane, and hinge means being provided between the lid and the cabinet to control movement of the lid between open and closed positions.

Preferably, the flanged panel is bent by leading the side flanges through transverse slots in a bed until a leading edge of the flanged panel activates a switch means and applying a bending force at the bending location in response to activation of the switch means. In a particularly preferred embodiment of the invention the bed is a split bed, one part of the bed being fixed and another movable part being pivotally mounted for movement between a rest position in line with the fixed bed to a bending position in which the movable part bends the flanged panel against a fixed bending element.

Preferably the flangeless element is formed by inserting a flat panel between two pairs of forming tools, one pair at each bending location, and the method includes the step of moving the panel and one of each of the pair of forming tools relative to the other of each pair of forming tools to bend the panel into a desired channel shape. Most preferably the forming tools comprise roller bars between which the panel is led for bending. In a particularly preferred arrangement the panel and one of each pair of formers is drawn downwardly, the panel bending against the other of the former tools as it is moved downwardly.

In a preferred embodiment of the invention, the panel is moved downwardly by a ram means. In this case preferably the ram means is operated in response to activation of a switch means on insertion of a panel for bending.

Ideally, the formers are adjustable to accommodate panels of different dimension and different desired bending locations.

The invention also provided refrigerator cabinets whenever manufactured by the method of the invention.

The invention will be more clearly understood from the following description thereof, given by way of example only with reference to the accompanying drawings, in which:Fig. 1 is a block diagram of a method for manufacturing refrigerator cabinets according to the invention, Fig. 2 is a perspective view of part of a moulding step in the method of the invention, Fig. 3 is a perspective view of another part of the moulding step, Fig. 3A is a cross-sectional view of part of a refrigerator cabinet after filling with insulation, Fig. 5 is a perspective view of a flanged panel used in the method of the invention, Fig. 4 is a perspective view of a machine used in bending the flanged panel of Fig. 5, Figs. 6 and 7 are cross-sectional views of the machine of Fig. 4 in operation, Fig. 8 is a perspective view of a flanged panel bent using the method illustrated in Figs. 5 and 6, Fig. 10 is a perspective view of a flat panel used in the method of the invention, Fig. 9 is a perspective view of a machine used for bending the flat panel of Fig. 10, Fig. 11 is a cross-sectional view illustrating the operation of the machine of Fig. 9, and Fig. 12 is a perspective view of the panel of Fig. 10 bent into a desired configuration using the machine of Figs. 9 and 11.

Referring to the drawings and initially to Fig. 1 thereof, in the method for manufacturing a refrigerator cabinet according to the invention, panels are first formed in step 1 into desired shape and configuration for forming a liner. In step 2 the liner is assembled to form a chest frame. In step 3 a heat exchanger coil is wound around the chest frame and an insulating and retaining tape is applied over the coil in step 4. In step 5, elements of an outer cabinet body are formed into a desired shape which are then assembled in step 6 around the chest frame. In step 7, the cabinet thus formed is turned so that an open side of the cabinet is lowermost and the cabinet is then lowered onto an inner mould part. An outer mould part is then closed around the cabinet and liquid plastic foam reactants, such as polyurethane foam reactants, are injected into the cavity defined between the chest frame and the outer cabinet body. The foam is cured so that the insulating foam fills the cavity between and bonds to the chest frame and outer cabinet. The mould is then opened and the refrigerator cabinet is removed from the mould. In step 8, a compressor, motor, evaporator and associated parts, are fitted to the cabinet. In step 9, the refrigerator system is charged with refrigerant. The refrigerator cabinet is then passed through a number of checks in step 10, testing the electrical circuity and leak testing the refrigerant circuit. In step 11, the cabinet is run for a prolonged period to ensure that a desired refrigeration temperature is achieved and maintained. The cabinet is then packaged in step 12 and lead to a conveyor turning table 13 for dispatch.

In more detail and referring particularly to Figs 2, 3 and 3A, a refrigerator cabinet which is diagrammatical ly illustrated in Fig. 3A, comprises an outer cabinet body 20 and an inner chest frame 21 which are spaced-apart to define a cavity 22 therebetween. The cabinet includes an open side 25. A mould which is used to fill the cavity 22 with liquid foam reactants is illustrated In Figs. 2 and 3 and comprises an inner mould part 27 and a number of hinged outer mould parts 28. The open side 25 of the refrigerator cabinet is lowered over the inner mould part and the outer mould parts 28 are then closed around the • cabinet and locked using the locking clasps, as illustrated. A top outer mould element includes a liquid foam reactant inlet opening 29 which, when closed, is aligned with an inlet opening 30 in the refrigerator cabinet. When the mould is closed, an operator injects liquid foam reactants into the cavity 22 by inserting a nozzle of an injector head 31 through the openings 29 and 30. Liquid plastic polyurethane foam reactants flow into the cavity 22 under pressure and the mould is cured allowing the liquid foam reactants to expand and rise to fill the cavity 22 and bond to the chest frame 21 and outer panels 20 of the refrigerator cabinet.

Referring now to Figs. 4 to 8, there is illustrated another step in the method of the invention which involves bending a liner panel 40 having side flanges 41 and a single end flange 42 into a desired L-shape, as illustrated in Fig. 8. The flanges 41 and 42 are first formed by using conventional bending techniques. Part of the flanges 41 are then cut away at 43 in a V-notch which defines a bending axis 44 extending across the panel 40. The machine used in the bending method is illustrated in Figs. -4, 6 and 7 and comprises a machine bed 50 having a first fixed part 51 and a second movable part 52 which is pivotally mounted to the fixed part 51 about a pivot axis 53 for movement between a flat panel receiving configuration, illustrated in Figs. 4 and 6, to a bending configuration illustrated in Fig. 7 for bending the panel 40 against a former 54. The movable part 52 of the bed is moved by a motor 56 which is operated in response to activation of a pair of switches 57 which are activated on insertion of a panel 40 as will be particularly apparent from Figs. 6 and 7.

Referring now to Figs. 9 to 12, apparatus used in the method of the invention for forming a flat panel 60 into a channel shaped liner panel 61, as illustrated in Fig. 12, for use as one of the inner chest frame panels is illustrated. The panel 60 is bent simultaneously at two spaced-apart locations by inserting the panel between two pairs of forming tools, one pair at each bending location. Each pair of forming tools comprises a fixed forming roller 65 and a movable forming roller 66, the roller 66 being fixed to a headpiece 67 attached to a ram, only portion 68 of which is illustrated. The ram 68 pulls the headpiece 67 and hence the roller former elements 66 and panel 60 downwardly against the former roller 65 to bend the panel into the channel shape 61 illustrated. The panel is pulled down as far as a base stop 69. It will be noted that the former rollers 65 are biassed inwardly to vary the forming pressure as the panel is drawn downwardly for optimum bending. Adjustable switches 70 are provided for sensing the presence of a panel 60 to be bent and for operating the ram 68.

The location of the former roller 66 may be varied as required to accommodate panels of different dimensions and varying bending locations.

The invention provides a method of forming a refrigerator cabinet in a highly cost efficient manner. The insertion of the liquid foam reactant in the manner described gives optimum curing time, total filling of the insulating cavity and good bonding adhesion between the chest frame and outer panels. The panel bending methods described are highly efficient in producing panels on demand to the manufacturing process line.

The method may be applied to manufacturing refrigerator cabinets of any desired type. The refrigerator cabinet may be provided with a lid comprising a single curved pane of transparent material and a frame surrounding the pane, the frame being hinged to control the movement of the lid between the open and closed positions.

Claims

1. A method for manufacturing a refrigerator cabinet comprising the steps of:forming panels into elements of an liner; forming panels into elements of an outer cabinet body; some of the elements being flanged elements and some of the elements being flangeless elements; at least some of the flanged elements being formed by forming side edges on some of the panels, cutting away portion of the side flanges at a desired bending location, and bending the flanged panel about a bending formation to form a flanged element which is bent intermediate the ends thereof; at least some of the flangeless elements being formed by bending a flat panel at two spacedapart locations simultaneously to form an element of generally channel shape; assembling the liner; applying a coil around the outside of the liner to form a chest frame; applying an insulating and retaining tape over the coil; assembling outer cabinet body elements to the chest frame; turning the cabinet thus formed so that an open side of the cabinet is lowermost; lowering the open side of the cabinet onto an inner mould part; 5 closing an outer mould part around the cabinet; injecting liquid plastic foam reactants into the cavity defined between the chest frame and the outer cabinet body; curing the foam so that the insulating foam 10 fills the cavity between and bonds to the chest frame and outer cabinet; opening the mould; removing the refrigerator cabinet from the mould; 15 fitting a compressor, motor, evaporator and associated parts to the cabinet; testing the electrical circuitry; charging the refrigerant system with refrigerant; 20 leak testing the refrigerant circuit; running the refrigerator cabinet for a prolonged period to ensure that a desired refrigeration temperature is achieved and maintained; and packing the refrigerator cabinet in preparation for dispatch. *

2. A method as claimed in claim 1 wherein the liquid foam reactants are injected into the cavity between » the chest frame and outer cabinet body at the side of the cabinet opposite to the open side.

3. A method as claimed in claim 1 or 2 wherein the method includes the step of applying a lid to the cabinet after filling of the cavity with insulating foam.

4. A method as claimed in claim 3 wherein the lid comprises a single curved pane of transparent material and a frame surrounding the pane, and hinge means being provided between the lid and the cabinet to control movement of the lid between open and closed positions.

5. A method as claimed in any of claims 1 to 4 wherein a flanged element is bent by leading the side flanges through transverse slots in a bed until a leading edge of the flanged element activates a switch means and applying a bending force at the bending location in response to activation of the switch means.

6. A method as claimed in claim 5 wherein the bed is a split bed, one part of the bed being fixed and another movable part being pivotally mounted for movement between a rest position in line with the fixed bed to a bending position in which the movable part bends the flanged element against a fixed bending element.

7. A method as claimed in any of claims 1 to 6 wherein the flangeless element is formed by inserting a flat panel between two pairs of forming tools, one pair at each bending location, and the method includes the step of moving the panel and one of each Of the pair of forming tools relative to the other of each pair of forming tools to bend the panel into a desired channel shape.

8. A method as claimed in claim 7 wherein the forming tools comprise roller bars between which the panel is led for bending.

9. A method as claimed in claim 7 or 8 wherein the panel and one of each pair of formers is drawn downwardly, the panel bending against the other of the former tools as it is moved downwardly.

10. A method as claimed in claim 9 wherein the panel is moved downwardly by a ram means.

11. A method as claimed in claim 10 wherein the ram means is operated in response to activation of a switch means on insertion of a panel for bending.

12. A method as claimed in any of claims 7 to 11, wherein the formers are adjustable to accommodate panels of different dimension and different desired bending locations .

13. A method for manufacturing a refrigerator cabinet substantially as hereinbefore described with reference to the accompanying drawings.

14. Refrigerator cabinets whenever manufactured by the method as claimed in any preceding claim.