1. Field of the Invention
This invention relates to insulated cabinet construction, and in particular to an insulated cabinet construction and method of assembly wherein a tubular member extends therethrough and includes means for preventing the escape of foamed-in-place insulation at an opening in one of the wall elements of the cabinet.
2. Description of the Background Art
In one conventional method of forming a refrigerator cabinet, a liner is spaced from a shell and foamed-in-place insulation is formed therebetween. To provide electrical power to electrical apparatus within the refrigeration cabinet, a wiring tunnel is extended through the cabinet. A problem arises in the provision of such through the cabinet structure in that the expanding foam insulation tends to escape through any opening in the shell or liner. To prevent such escape, foam stop means are provided for stopping the foaming action at the opening. The present invention is concerned with a wiring-tunnel arrangement having an improved foam stop means for effectively preventing the escape of foam material through wiring tunnel openings provided in the shell and liner of the cabinet assembly.
A number of different devices have been developed for passing wiring through panels and insulated wall members. Illustratively, in U.S. Pat. No. 3,424,857 of Hubert B. Miller et al, a wiring grommet is installed in a panel by means of a circular groove surrounding the outer periphery of the grommet. In the Miller et al grommet, an internal cylindrical groove is provided near the outer periphery of the grommet to permit controlled collapsing for facilitated insertion of the grommet in the circular panel hole.
Richard J. Carbary et al, in U.S. Pat. No. 3,440,308 shows a check valve structure arranged to permit the entrance of the foam injection conduit and which responds to the internal pressure caused by the foaming of the insulation to shut off the conduit entrance opening.
Roger M. Boor, in U.S. Pat. No. 3,619,482, shows a wiring tunnel having its opposite ends fastened to the liner and shell of the cabinet respectively. The wiring tunnel support has a protrusion extending through an opening in the liner. Another sheet metal wall is secured to an external flat surface on the protrusion so as to be spaced from the liner.
John J. Schaus shows, in U.S. Pat. No. 4,118,451, which patent is owned by the assignee hereof, a foam stop comprising a flexible sheet secured to one or the other of the liner or shell, permitting the foaming insulation to lift the projecting portion of the sheet so as to cause it to extend across an opening from the insulation space and thereby close that opening. A backup member is disposed across the opening to limit the outward deflection of the sheet by the foam.
In U.S. Pat. No. 4,165,105, Thomas M. Hahn shows a transition sleeve for a refrigerator cabinet. The sleeve is defined by a tubular body of relatively rigid material and includes radially extending integral flanges at each end for sealing engagement with the shell and liner of the cabinet. The sleeve is rotatable in one of the walls by means of integral locking tabs. Refrigerant tubing extends through the sleeve and is sealed thereto by gum or the like.
A sealing grommet for use in refrigerator cabinets is disclosed in U.S. Pat. No. 4,180,297 of Donald W. Abrams. The sealing grommet provides a seal for electrical wires and is defined by a cylindrical hollow body of rigid material having a core of soft material glued to the outer body. Each of the body and core is split longitudinally to receive the electrical wires. A second grommet engages the core so as to seal the core to the shell. An integral annular flange is provided with locking lugs to mount the body on the inner liner of the cabinet.
Another transition sleeve structure is illustrated in U.S. Pat. No. 4,186,945 of Thomas M. Hahn. The sleeve includes annular flanges which are flared outwardly to sealingly engage the shell and liner. The insulation foam is caused to act against the convex portion of the flange to enhance the sealing force.