Heat shielded dock pad

A compressible seal for a loading dock includes a pliable heat shield that helps protect the seal from concentrated heat generated by a truck's taillight being pressed against the seal. The seal includes a compressible foam core protected by a tough outer covering. The heat shield is preferably placed against the foam core, just underneath the cover. The shield reflects heat away from the foam and helps disperse the heat over a broader area to reduce the peak temperature of any hot spots.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention generally pertains to a loading dock and more specifically to a dock seal disposed around a doorway of the dock.

2. Description of Related Art

When an exterior doorway of a building is used as a loading dock for vehicles, especially trucks, the perimeter of the doorway typically includes a seal known as a dock pad. The dock pad seals off gaps that would otherwise exist between the exterior face of the building and the back end of the truck. This allows cargo from the rear of the truck to be loaded or unloaded while dockworkers and the cargo are protected from the weather. Usually a side dock pad runs vertically along each lateral edge of the doorway, and a top or head pad runs horizontally along the doorway's upper edge. A typical pad comprises a resiliently compressible foam core protected by a fabric outer covering. Sealing is often provided by backing the truck up against the pad, so that the pad compressively conforms to the shape of the rear of the truck.

When a truck backs into a loading dock, in many cases, taillights on the rear of the truck press against the dock pad. This often occurs with taillights that are located along the upper rear edge of the truck, whereby the lights push against the head pad that is mounted over the doorway. Normally, this does not create a problem. However, if the driver of the truck inadvertently leaves the lights on for an extended period (e.g., while the truck is being loaded or unloaded), the dock pad absorbs much of the heat generated by the taillights. The pad's core being made of foam, which is inherently a poor conductor of heat, tends to keep the heat concentrated to a relatively small area of the pad near the light. Thus, the temperature of that area can rise significantly. Excessively high temperatures can degrade the materials of the pad, or in some extreme cases, may even cause portions of the pad to burn or melt.

Perhaps one solution would be to make a dock pad of materials that could tolerate higher temperatures. However, such an approach would likely compromise other desirable qualities of the pad, such as abrasion resistance, puncture resistance, weather resistance, compressibility, resilience, lightweight, appearance, etc., as the materials currently being used are often chosen for the purpose of optimizing these qualities.

SUMMARY OF THE INVENTION

In order to provide a dock seal that can tolerate heat generated by a vehicle's taillight, a dock pad comprising a compressible foam core with a pliable outer cover includes a heat shield that helps protect the foam core and its outer cover from excessive heat.

In some embodiments, a heat shield is interposed between a dock pad's foam core and its cover to retain at least some of advantages of the cover.

In some embodiments, a dock pad is provided with a heat shield that has appreciable thermal conductivity to help disperse heat.

In some embodiments, a dock pad is provided with a heat shield that has appreciable reflectivity to reflect some heat away from a foam core of the dock pad.

In some embodiments, a dock pad is provided with a heat shield that can withstand a higher temperature than a foam core of the dock pad, whereby the heat shield helps protect the foam core from heat.

DESCRIPTION OF THE PREFERRED EMBODIMENT

To create a weather seal between the rear of a truck10(or some other vehicle) and the perimeter a loading dock doorway12, a dock pad14(or dock pad assembly) is installed, as shown inFIG. 1. In this example, dock pad14includes a side pad16mounted along each lateral edge of doorway12, and a top or head pad18installed along the doorway's upper edge. Pads16and18are resiliently compressible, so as truck10backs up against them, the pads compressively and sealingly conform to the contour of the truck's rear edges.

To provide dock pad14with durability and resilient compressibility, pad14includes a resiliently compressible foam core20covered by a tough outer cover22, as shown inFIG. 2. In this example, core20consists of a polyurethane or foamed polyester, such as, for example, an L24 open-cell polyurethane foam provided by Leggett & Platt of Carthage, Mo. It should be appreciated by those skilled in the art; however, that a wide variety of other synthetic or natural foams may also work well. In some embodiments, cover22is a 3022_MFRLPC_DC7 material provided by the Seaman Corporation of Wooster, Ohio. Other examples of cover materials would include, but are not limited to, HYPALON, canvas duck, rubber-impregnated fabric, and coated nylon fabric.

In assembling pad14, cover22wraps at least partially around core20, and the two are attached to a relatively rigid backer24, such a formed steel channel or a wood board. Backer24, in this example, provides a mounting surface26that facilitates the installation of pad14. A conventional fastener or anchor can be used to attach backer24to a wall28of a loading dock30. In some embodiments, cover22attaches to the side edges of backer24by any one of a variety of fasteners including, but not limited to, screws, VEECRO, rivets, hooks, and adhesive. Core20can be frictionally held to cover22, or the two can be joined in a more positive manner. For example, cover22can be connected to core20with adhesive, straps, hooks, VELCRO, stitches, screws, etc.

To make pad14more resistant to heat, such as heat generated by a taillight32pressing against certain points34on a sealing surface36of pad14, a heat shield38is attached to pad14. In some embodiments, heat shield38is incorporated within a Commercial Material RTCM01, which consists of two flexible sheets or layers of perforated aluminum foil reinforced with a polyethylene scrim or fabric, as provided by Radiant Technology, of Dallas, Tex. The flexibility of shield38is preferably sufficient to allow dock pad14to compressively conform to the contour of the truck's rear edges and then decompress to the pad's original shape. Heat shield38can be attached to pad14using adhesive, friction, straps, stitches, and/or various other fasteners. Shield38can be attached to the exterior or interior of pad14, however; shield38is preferably installed between cover22and foam core20for structural, functional, and aesthetic reasons.

Placing shield38underneath cover22, helps keep cover22exposed to the outside, thus taking advantage of the cover's toughness, weather resistance and pliability. Moreover, shield38preferably has a higher reflectivity than core20and cover22. This can be beneficial in cases where the cover can withstand a higher temperature than the core, wherein “withstand a higher temperature” means a material can be raised to the higher temperature and then substantially recover its original properties after its temperature returns to normal. For example, if the foam of core20has an auto ignition point (i.e., temperature at which the material self-ignites without being triggered by a spark or a flame) of 700 degrees Fahrenheit and cover22has an auto ignition point of 900 degrees, then heat shield38with high reflectivity could reflect heat away from the foam and redirect it into cover22, which may be able to handle the heat better. In some embodiments, both cover22and core20have a lower auto ignition point than heat shield38(e.g., when shield38is one of the two layers of aluminum foil contained within Commercial Material RTCM01).

To reduce peak temperatures of core20and/or cover22when heated by taillight32, heat shield38is made of a material that has a higher thermal conductivity than core20and/or cover22. The maximum temperature at areas of concentrated heat, such as points34, is reduced by shield38being able to effectively disperse the heat over a broader area. The term, “thermal conductivity” refers to a material's ability to conduct heat of a given temperature gradient along a given length and through a given cross-sectional area of the material, thus thermal conductivity is a property of the material itself, and is generally independent of the material's shape. A typical unit of measure for thermal conductivity would be (Btu)/(hr)(ft)(° F.).

To provide even greater heat protection, another embodiment, similar to that ofFIG. 2, provides a dock pad14′ with two heat shields38′, as shown inFIG. 3. It is believed that additional heat protection is provided by the additional overall thickness of the two shields and perhaps partially provided by virtue of an additional slight air interface40that may exist between the two shields38′. Moreover, for a given total thickness, two individual shields instead of one relatively thick one is more flexible, just as a stack of individual cards is more flexible than a stack of cards whose faces are glued together.

A strap42inserted through a slit44in foam core20′ helps hold the two shields38′ in place. A loop46at each end of strap44engages holes48in shields38′; however, strap42could attach to shields38′ in a variety of other ways as well. Also, strap42could feed around the back of core20′ to eliminate the need for slit44; however, strap42extending through slit44helps keep strap42and shields38′ from shifting along the length of a pad.

Although the invention is described with reference to a preferred embodiment, it should be appreciated by those skilled in the art that various modifications are well within the scope of the invention. For example, although the illustrated dock pads have cross-sections that are generally rectangular, various other shapes are also well within the scope of the invention. Moreover, the shape of the head pad could be different than that of the two side pads. One or more heat shields can be applied to just the head pad, just the side pads, or applied to both the head and side pads. Therefore, the scope of the invention is to be determined by reference to the claims that follow.