Front cover for transport refrigeration unit

A transport refrigeration unit has a front cover that includes a grille supported by and attached to a surround assembly by means of latch members.

FIELD OF THE INVENTION

The present invention relates generally to the art of transport refrigeration units and, more particularly, to a grille and surround assembly for the outer protective covers for such units.

A typical transport refrigeration unit of the type designed for mounting on the front face of a tractor trailer unit comprises a one piece, self-contained fully refrigerant charged, prewired, refrigerant/heating unit powered by a diesel engine. In such a design the evaporator section fits into a rectangular opening in the upper portion of the trailer front wall. When installed, the evaporator section is located inside the trailer; and the condensing section is outside and on the front of the trailer. The condensing section consists of an engine-compressor drive package, condenser fan, condenser coil, radiator coil, control panel, relay module, refrigerant controls, piping, wiring and associated components.

Structural frame members support all of the components and facilitate attaching of the unit to the trailer front face. Also supported by the structural framework is an outer cover which includes the necessary air inlet and outlet openings for air cooling of the condenser coil, and doors which may be opened to provide access to the interior of the unit for maintenance and service.

The air inlet for cooling of the condenser coil is provided by way of a grille located at the upper, front face of the cover. Typically, the grille is composed of a durable rigid plastic material, such as for example acrylonitrile butadiene styrene (ABS) material or polyethylene or polyolefin material, and is mounted to a surrounding support structure, commonly referred to as a surround assembly, that is mounted to the framework of the refrigeration unit. In conventional practice, the grille is mounted to the surround assembly by means of a plurality of threaded fasteners arranged in spaced relationship about the periphery of the grille.

SUMMARY OF THE INVENTION

It is an object of an aspect of the invention to provide an improved method for attaching a front grille to a supporting surround assembly.

It is an object of an aspect of the invention to provide a transport refrigeration unit having a front cover that includes a grille attached to a supporting surround assembly by compliant latch members.

In one aspect of the invention, a transport refrigeration unit of the type adapted to be mounted on the front wall of a trailer for conditioning the environment interior of the trailer has a front cover for enclosing the refrigeration unit, including a grille that is supported from a surrounding structure by compliant latching members. The support structure has a center opening defined by a plurality of peripheral sides and adapted to receive the grille. The grille has a plurality of latch members extending rearward from its periphery and the support structure has a plurality of openings in its peripheral sides about the center opening for receiving the latch members in latching relationship whereby the grille is supported by the support structure.

The latch members may be disposed at spaced intervals about the periphery of the grille and the plurality of openings in the peripheral sides of the support structure are commensurate in number to the plurality of the latch members and arranged in mating relationship to the plurality of latch members. In an embodiment, each of the latch members is a leg extending rearward from a proximal end integral with the grille to a distal end extending through a respective one of the plurality of openings in the peripheral sides of the support structure. Each leg has a foot at its distal end that extends outwardly therefrom so as to engage the support structure in latching relationship.

In an aspect of the invention, a method is provided for attaching the grille of the front cover of a transport refrigeration unit to a surrounding support structure with latch members. In an embodiment, the method includes the steps of providing a plurality of latch members extending rearward from a periphery of the grille, and providing a plurality of openings in the support structure about the periphery of a center opening in the support structure for receiving the latch members in latching relationship.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now toFIG. 1, a fragmentary front part of a large transport trailer10is shown with a transport refrigeration unit11mounted on the front wall of the trailer. For purposes of the present description the terms “roadside” and “curbside” will be used in describing various components of the refrigeration unit and its cover. As viewed inFIG. 1, the right hand side of the unit will be referred to as the roadside and the left hand side of the unit as the curbside of the unit.

With this reference, the transport refrigeration unit11as illustrated inFIG. 1has a cover assembly20having a lower cover assembly21and an upper cover assembly23. The lower cover assembly21includes a curbside front door14, a curbside outer door15, a roadside front door16, a roadside outer door17, all shown in their closed positions, side panels22and bottom panel26. The front doors14and16are vertically hinged at their respective outer edges so as to swing outwardly to open to provide a large access opening at the front of the unit, thereby providing access to the inner structural components of the unit as well as some of the components of the refrigeration system itself. The outer doors15and17are mounted within the respective side panels22and vertically hinged at their respective rear edges such that they pivot open from front to back to provide additional access openings to the interior of the refrigeration unit at the sides of the unit. Latches18and19are provided for latching and unlatching the front roadside door16and side roadside door17, respectively. The bottom panel26is attached to the lower cover assembly for purposes of closure and to improve the aesthetics of the unit.

Attachment of the refrigeration unit11to the trailer10is carried out by connection of an outer peripheral planar structural steel framework designated generally by reference numeral25. It should be appreciated that this framework is not normally visible when the unit is properly installed on a trailer unit, however for purposes of illustration, at least a portion of the structural framework is illustrated inFIG. 1. All of the component assemblies which define the outer cover of the refrigeration unit11are mounted to the various structural members of the framework25.

The upper cover assembly23comprises a relatively rigid front grille member40and a relatively flexible support structure42, also referred to herein as the surround assembly, disposed in surrounding relationship therewith. The grille member40is positioned in overlying relationship with a center opening67in the surround assembly42and the condenser heat exchanger therebehind (not shown). The grille is provided with a large number of openings41therethrough to facilitate air flow for efficient heat transfer to cool the condenser coil of the refrigeration unit. A top panel27may be attached to the upper cover assembly of the unit for purposes of closure and to improve the aesthetics of the unit. It will be appreciated that the door, panel, surround assembly and grille components described above are designed to cooperate to fully enclose the refrigeration unit11to provide protection from the environment and road hazards and to aerodynamically and aesthetically enhance the unit.

Referring now toFIGS. 2-3, the front grille member40is shown as generally rectangular in shape having sides51,52,53and54. It is slightly curved from front to back so as to wrap around the front face as shown. It has a plurality of horizontally disposed, and vertically spaced, louver members56, in combination with vertically disposed spacer members57therebetween, to define in combination the plurality of openings41for the flow of air for cooling the condenser coil (not shown). Surrounding the grille member40is the surround assembly42which has a side61bordering the grille side51, a side62bordering grille side52, a side63bordering the grille side53, and a side64bordering grille side54. The sides61,62,63and64cooperatively form a periphery about and define the rectangular shaped, center opening67in the surround assembly42for accommodating the attachment of the grill member40and the flow of air therethrough. In an embodiment, the sides61,62,63and64are all integrally formed in a single piece. Both the top62and the bottom64have rounded edges and extend rearwardly. The sides63and66also have rounded front edges and extend rearwardly in a curved manner, but also have rearwardly extending wing structures68and69, respectively.

The surround assembly42is secured to the structural framework25, typically by bolts or other threaded fasteners. In the exemplary embodiment depicted, the wing structures68and69of the surround assembly42have respective indentions71with surfaces74for the receiving of threaded fasteners (not shown) therethrough for the purpose of securing the wing structures68and69to the appropriate structural members of the framework25. In the side61of the surround assembly42a plurality of holes78are formed near the rear edge thereof for securing the side61to the structural framework25. Similarly, attached to and extending rearwardly from the bottom63of the surround assembly42is a flange having holes (not shown) formed therein for receiving fasteners for attaching the flange with a cooperating structural member of the framework25.

Referring now toFIGS. 2-5, the front grille member40is attached to the surround assembly42by a plurality of latch members45received in respective mating openings of a corresponding plurality of openings65in the surround assembly42. The latch members45are disposed at spaced intervals about the periphery of the grille40and extend rearward from the sides51,52,53and54of the grille40. The corresponding plurality of openings65are disposed at spaced intervals about the periphery of the center opening67in the surround assembly42and are arranged in the sides61,62,63and64of the surround assembly42such that each opening65is positioned to receive a corresponding latch member45when the front grille member40overlays the center opening67in the surround assembly42.

Each of the latch members has a leg47extending rearward from the periphery of the grille40. Each leg has a proximal end integral with the grille40and a distal end having a foot49extending laterally therefrom. When the front grille member40is assembled to the surround assembly42, the distal end of the leg47of each latch member45extends through its corresponding opening65such that the foot49overlaps the rearward surface69of the surround assembly42, thereby securing the latch members45within the openings65in latching relationship with the surround assembly and holding the grille40in position in overlaying relationship with the center opening67of the surround assembly42.

In the embodiment of the transport refrigeration unit of the invention depicted in the drawing, the grille40is attached to the surround assembly42of the cover by means of latch members45, the legs47of which may be simply inserted into the corresponding openings65in the periphery of the support assembly42until the foot49of each latch member45snaps into latching relationship with the surround assembly42. The plurality of latch members disposed at spaced intervals encompassing the entire periphery of the grille enhances the structural rigidity of the upper cover assembly formed of the grille40and the surround assembly42to which it is attached and provides for more uniform distribution of vibration-induced stresses across multiple compliant attachment points. Additionally, no tools are required to assemble the grille40to the surround assembly42. However, it is to be understood that, if desired, additional mechanical fasteners, for example threaded fasteners, can be installed after the grille40has been snapped in place to the surround assembly42to further secure the grille40to the surround assembly42.