The present multi-seal dock seal has a pair of side seal assemblies that form both a compression seal and a wipe seal with a trailer. The side seal assembly secure to the building wall along the door opening. A wipe seal pad is positioned in front of a compression pad by an extension pad. The flexible pads are formed of polyurethane foam wrapped with a PVC vinyl coated polyester cover. The wipe and extension pads are more rigid than the compression pads, and the compression and extension pads are joined together to further support the extension pad. The side seal assemblies provide sealing zones to accommodate a wide range of truck and trailer types. The multiple seals formed by the multi-seal dock seal ensure a good seal with the trailer when the trailer fully backs into the bay, and when an obstruction prevents it from fully backing into the bay.

TECHNICAL FIELD OF THE INVENTION

This invention relates to a dock seal for a loading dock that forms multiple weather seals along the side walls and around the roof of a trailer when the trailer is parked in the loading dock trailer bay.

BACKGROUND OF THE INVENTION

Dock seals form a weather seal between a trailer and a loading bay. Various types of dock seals have been developed and are know in the industry. Inflatable seals that engage the sides and top of a trailer are described in U.S. Pat. Nos. 3,714,745, 3,939,614 and 5,109,639 to O'Neal, Frommelt and Moore, respectively. A portable inflating seal that engages the rear end of a trailer is disclosed in U.S. Pat. No. 6,073,402 to Moody. An expanding seal engaging the sides and top of a trailer is disclosed in U.S. Pat. No. 4,020,607 to Bjervig. A compression seal that seal against the rear end of the trailer is disclosed in U.S. Pat. No. 6,170,205 to Styba. A compressible deflecting seal that engages the side and top of a trailer is disclosed in U.S. Pat. No. 4,679,364 to Fettig. A compressible L-shaped seal that engages the sides and top of a trailer is disclosed in U.S. Pat. No. 4,213,279 to Layne. Various problems exist with each of these dock seals. For example, conventional compression seals are impractical for large variations of trucks and trailers especially those with rear steps or tail gates. Conventional wiping seals and shelters do not provide as good of seal efficiency of a compression seal. A problem with conventional dock shelters is that they include rigid materials that are prone to damage by the trailers when backing into the loading bay. The present invention is intended to resolve these and other problems.

BRIEF DESCRIPTION OF THE INVENTION

The present invention pertains to a multi seal dock seal for a loading dock. The multi-seal dock seal has a pair of side seal assemblies that include a compression seal pad and a wipe seal pad. The side seal assemblies are secured along the sides of the door opening and extend at least the height of the opening. A wipe seal extension pad abuts the compression seal and positions the wipe seal from the front surface of the compression pad. The pads are formed of polyurethane foam wrapped with a PVC vinyl coated polyester cover. The foam forming the wipe seal and extension pads is more rigid than the foam forming the compression seal pads. The compression seal and extension pads are wrapped by a single vinyl cover to form a unitary structure and provide support to the extension pad. The side seal assemblies provide sealing zones along the sides of the trailer to accommodate a wide range of trailer widths, and to accommodate trailers that are not exactly centered with the dock door opening.

An advantage of the multi-seal dock seal is that it accommodates a full range of truck types. The multi-seal dock seal provides both a compression seal and a wipe seal to seal the truck or trailer and prevent rain, wind and humidity, as well as insects and debris from blowing into or otherwise entering the interior of the building when the loading bay door is open to load and unload goods from the trailer. These two seals provide the efficiency of a compression seal and the wiping action of a perimeter seal to cover the full range of truck types. The multiple seals formed by the multi-seal ensure a good seal between the trailer and the loading bay both when the trailer is able to fully back into the bay, and when the trailer has an obstruction such as a step platform that prevents it from fully backing into the bay. Even in this later situation, the multi-seal dock seal keeps the outside air, rain, humidity, dust and bugs from entering the loading bay to provide a safe and comfortable environment inside the loading dock building and avoid heating and cooling losses.

Another advantage of the multi-seal dock seal is that when desired, it is provided with a custom fit top seal assembly. The top seal assembly can include a canopy pad and curtain flap, as well as a top compression seal. The top and side seal assemblies join together to provide continuous seal around the top and sides of the trailer.

A further advantage of the multi-seal dock seal is its ability to hold up to wind loads. A mounting plate rigidly secures the integrated compression and wipe extension pad structure to the building wall. The compression seal abuts and supports the side of the wipe seal extension pad. These compression and wipe pads are glued together and wrapped together by a single vinyl cover. The wipe seal extension pads and wipe seal pads are formed of a more rigid polyurethane foam material to provide further support to the wipe seals. Securement strips are also located on the top and bottom ends of the side seal assemblies to provide additional support to the wipe seals. The wipe seals are free to flex inwardly to engage the sides of a trailer, but are supported by the rigid mounting plate, abutting engagement with the compression seals, the added rigidity of the extension pads and the securement strip to prevent the wind from blowing the wipe seals outwardly or dislodging them from the side seal assemblies.

A still further advantage of the multi-seal dock seal is that its wipe seal does not become pinched against the compression seal during use. The thickness of the compression seal, the outward length of the wipe seal extension and the inward length of the wipe seal are sized to prevent the wipe seal from engaging and being pinched against the front surface of the compression seal pad when a trailer pushes against and bends the wipe seal back. This non-binding structure prevents damage to the multi-seal. The wipe seal pad does not engage the compression seal when the multi-seal dock seal forms either a single wipe seal when the trailer is prevented from fully entering the dock bay, or a multi-seal when the trailer fully enters the dock bay.

A still further advantage of the multi-seal dock seal is that the length of the wipe seal pads and the width of the compression pads are adjustable. For example, the length of the wipe seal pad can be adjusted to extend into the door opening projection more than the compression seal pad extends into the opening projection. Thus, the side seal assemblies can adjust the width of the compression seal pads and length of the wipe seal pads to adjust the engagement areas or zones (CSA and WSA) to meet the needs of a particular loading dock facility or even a particular loading bay.

A still further advantage of the multi-seal dock seal is that it is constructed of flexible components. Other than their mounting plate secured flush against the building wall, each side seal assembly is constructed of flexible components or pads that extend or are positioned outwardly from the building. Similarly, the top seal assembly is constructed of flexible components, that extend or are positioned outwardly from the building. A truck or trailer that is not properly centered or aligned with the multi-seal dock seal sealing zones (CSA and WSA) when it backs into the loading bay will contact flexible structures to help avoid damage to the truck or trailer as well as the multi-seal dock seal structure itself.

A still further advantage of the multi-seal dock seal is that its side seal assemblies are compatible with a rigid header, canopy or head frame structure. The side seal assemblies easily fit under these structures. Their curtains overlap the side seal assemblies to provide continuous seal around the top and sides of the trailer.

Other aspects and advantages of the invention will become apparent upon making reference to the specification, claims and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While this invention is susceptible of embodiments in many different forms, the drawings show and the specification describes several embodiments of the invention. It should be understood that the drawings and specification are to be considered an exemplification of the principles of the invention. They are not intended to limit the broad aspects of the invention to the embodiments illustrated.

The present invention pertains to a multi-seal dock seal for a building3with a loading dock bay5. As shown inFIGS. 1A and 1B, the outer wall7of the building3forms the perimeter of a bay opening10. Bumpers8are typically located on the outside wall7. The door opening10has a perimeter11formed by its vertical side edges12, horizontal top edge13and the floor14of the building. The door opening perimeter11forms a door opening projection15that extends outwardly into the loading bay5as best shown inFIGS. 2B and 2C. The opening10includes a door16that is opened to load and unload goods, and closed to seal the interior of the building from the weather. The bumpers8are below the door opening10and floor14of the building3and above the ground or approach17leading into the loading bay5. A conventional trailer20backs into the loading bay5to load or unload goods. The trailer20has a floor21, opposed side walls22and a roof24that form an opening25at its rear end27. The rear end27of the trailer20has a tailgate or ICC bar28that engages the bumpers8when the trailer has fully entered the loading bay as shown inFIG. 3. The loading bay can include a conventional rigid header frame and curtain structure19as shown inFIG. 9.

The multi-seal seal dock seal is generally referred to by reference number30inFIGS. 1-8. The multi-seal30provides both a wipe seal100and a compression seal105with the truck or trailer20, and integrates these two distinctly different types of trailer seals100and105into one distinct integrated multi-seal design to provide both the wiping action of a perimeter wipe seal100and the efficiency of a compression seal105to cover the full range of truck types. The different and multiple seals110formed by the multi-seal dock seal30ensure a good seal between the trailer20and the loading bay5when the trailer20is able to fully back into the dock5as inFIGS. 3, 4A. Even when the trailer is unable to fully back into the dock, such as when a step platform29prevents the rear end of the trailer from engaging the loading dock bay bumpers8, the multi-seal dock seal30forms a continuous single seal or wipe seal100to ensure an adequate seal between the trailer20and the loading bay5as shown inFIGS. 4B and 5B. Even in this single-seal situation, the multi-seal dock seal30keeps the outside air, rain, humidity, dust and bugs from entering the loading bay to provide a safe and comfortable environment in the loading bay building3and avoid heating and cooling losses.

The multi-seal dock seal30is formed by a pair of side seal assemblies40. The multi-seal dock seal30can include a cooperating custom fit top seal assembly80as shown inFIGS. 1A-B,3and5A-C, or the conventional rigid header frame and curtain19as shown inFIG. 9. Each side seal assembly or member40has top and bottom ends41and42, and extends vertically along the full height of the vertical side12of the dock door opening10. The conventional rigid header frame and curtain19or top seal assembly80has side ends81, and extends the full width of the horizontal top13of the opening10.

As shown inFIGS. 4A-Cand6, each side seal assembly40has a ridged backing plate45and three compression type foam pads50,60and70. The backing plate or member45is bolted or otherwise rigidly secured to the outer wall7of the building3as shown inFIGS. 1A-B. This plate45spans the height12of the loading bay opening10, and is about two inches thick and ten inches wide. The plate45is preferably made of wood, steal or rigid plastic, and is robustly designed to prevent warping, cracking or other deformation during use. Each backing plate45is installed with its inside edge offset a uniform distance of about two inches from the side edge12of the bay opening10.

The first flexible component or compression pad50spans the height12of the bay opening10, and is glued or otherwise firmly secured to the backing plate45along that entire distance. The pad50and has a non-compressed, trapezoidal, cross-sectional shape as best show inFIGS. 4B-Cand6. The front and rear surfaces51and52of the pad50define its non-compressed thickness of about ten inches extending away from the building wall7. The side surfaces53and54of the pad50define its width. The width along its rear or fixed base surface52is about three inches. This width increases to about nine inches along its compressible front or outer trailer engaging surface51. The front surface51of each trapezoidal shaped compression pad50extends into the bay opening about four inches. The pad50has an interior55that is formed by a compression type foam, and is preferably an open cell polyurethane foam with a density of about 1.2 pounds per cubic foot and an ILD of about 28-36 lbs/50 sq·in, a tensile strength of about 12 lbs/foot, a tear strength of about 1.2 lbs/in., and memory to resiliently return to its original shape when the trailer20pulls away and the foam is not compressed.

The second flexible component or forward extension pad60spans the height12of the bay opening10, and is also glued or otherwise firmly secured to the backing plate45along that distance. The pad60has a rectangular cross-sectional shape as best shown inFIGS. 4A-Cand6. The length of the extension pad60is defined by its front and rear surfaces61and62. The pad length extends a distance of about two feet from the building wall7. The side surfaces53and54define the width of the extension pad60. This uniform width is about seven inches. The extension pad60has an interior65that is formed by a compression type foam, and is preferably an open cell polyurethane foam with a density of about 2 lbs/cubic foot, an ILD of about 90-110 lbs/50 sq·in, a tensile strength of about 12 lbs/foot, a tear strength of about 1.2 lbs/in., and memory to resiliently return to its original shape when the trailer20pulls away and the foam is not compressed or flexed.

The extension pad60is positioned in abutting engagement with and radially outward from the compression seal50relative to the door opening10. The inner side63of the extension pad60is flushly engages the outside surface53of the compression pad60, and the pads50and60are glued together to provide additional lateral strength and stability to the extension pad60. The compression and extension pads50and60are also wrapped in a single durable vinyl covering67to form a single or integral structure68to further provide strength and stability to the extension pad60. The vinyl covering67is preferably a PVC vinyl coated polyester having a weight of about 22 to 50 ounces per square yard. The cover67has flap portion that extends to cover and hide the backing45when installed. A vent is located on the bottom of the wrapped compression seal50and extension pad60structure68as shown inFIG. 7.

The third flexible component or inward extending wiping pad70spans the height12of the dock opening10, and is secured to the outer end61of the extension pad60along that distance. The pad70has a length defined by its inner and outer ends71and72of about sixteen inches. The wipe seal pad70length extends inwardly into the bay opening projection15about the same amount as the compression seal pad50, or about four inches into the bay opening projection as shown inFIGS. 2B and 4C. The inner and outer surfaces73and74of the pad70define its thickness, which is about two inches. The flexible wipe pad70extends inwardly toward the door opening projection15and is in registered alignment with the compression pad50.

The pad70has an interior75that is preferably made of the same type of open cell polyurethane foam as the extension pad60, and has a density of about 2 lbs/cubic foot, an ILD of about 90-110 lbs/50 sq·in, a tensile strength of about 12 lbs/foot, a tear strength of about 1.2 lbs/in., and memory to resiliently return to its original shape when the trailer pulls away and the foam is not compressed or flexed. The wipe pad70is wrapped in a durable vinyl covering77. This covering52has securement flaps78to firmly join the wipe seal pad70to the front or outer end61of extension pad60, such as via Velcro or other suitable form of securement. The bottom end42of each side seal assembly40has a flexible securement strip or sheet79. The sheet or stabilizing piece79allows the wipe seal pad70to bend inwardly when engaging the side22of a trailer20. The strip79prevents the wind from blowing the wipe pads70outwardly. The sheet79also closes off a gap between the pads50,60and70that would otherwise allow air to leak by the side seal assemblies40.

When the pads50,60and70are in their non-flexed and non-compressed conditions (FIG. 4C), the inner and outer surfaces73and74of the flexible pad70are in generally parallel registered alignment with the front surface51of the compression pad50. When the pads50,60and70are in this non-flexed and non-compressed condition, the surfaces51,63and73of pads define an open area or space between surfaces73and51that has a generally square shape. When engaging the sides22of a trailer20to form a wipe seal100(FIGS. 4A-B), the flexible pad70is bent rearwardly toward the building wall7with its inner end71coming close to but not touching the front surface51of the compression pad50.

The thickness of the compression pads50and the length of the extension and wipe seal pad60and70can be adjusted for various loading dock installations. For example, the length of the wipe seal pad70can be adjusted to extend into the door opening projection15more than the compression seal pad50extends into the opening projection as shown inFIG. 2C. Thus, the side seal assemblies40can adjust the width of the compression pads50and length of the extension and wipe pads60and70to adjust the engagement areas or zones (CSA and WSA) to meet the needs of a particular loading dock facility3or even a particular loading bay5.

As best shown inFIGS. 5A-Cand8, the top seal assembly80has a ridged backing plate82, compression type foam pads84and90, and a hanging flap or curtain98. The backing or mounting plate82is bolted or otherwise rigidly secured to the outer walls7of the building3. The mounting plate82is similar to plate45, and is about two inches thick, about twelve inches wide and spans the top width13of the loading bay opening10. The plate82is preferably wood, seal or rigid plastic that is robustly designed to prevent warping, cracking or other deformation during use. The plate82is installed with its lower edge offset a uniform distance of about one inch from the top edge13of the bay opening10.

The first flexible component or compression pad84spans the top width13of the bay opening10, and is glued or otherwise firmly secured to the backing plate82along that distance. The compression pad84has a generally square cross-sectional shape as show inFIGS. 5A-Cand8. The surfaces85-88of the pad84define its thickness and width of about eight inches. The pad84does not extend into the bay opening10. The compression seal pad84has an interior89that is preferably formed from an open cell polyurethane foam with a density of about 1.2 pounds per cubic foot and an ILD of about 28-36 lbs/50 sq·in, a tensile strength of about 12 lbs/foot, a tear strength of about 1.2 lbs/in., and memory to resiliently return to its original shape when the trailer20pulls away and the foam is not compressed. A vent is located on the underside88of the compression pad84.

The second flexible component or canopy pad90spans the width13of the door opening10, and is glued to the mounting plate82along that distance. The pad90is positioned radially outward or upward from the compression seal90relative to the door opening. The lower surface of the canopy pad90is in abutting engagement with the upper surface87of the top compression pad84, and the pads and are glued together to provide support for the canopy pad90. The canopy pad90has a substantially triangular cross-sectional as shown inFIGS. 5A-Cand8. The pad90has a width of about four inches at its base or rear end91, and a width of about one inch at its front or outer end92. The canopy pad90extends forward from the wall7a distance of about 2 feet. The pad90has an interior95that is formed from a compression type foam that is preferably an open cell polyurethane foam with a density of about 2 lbs/cubic foot, an ILD of about 90-110 lbs/50 sq, in, a tensile strength of about 12 lbs/foot, a tear strength of about 1.2 lbs/in., and memory to resiliently return to its original shape when the trailer pulls away and the foam is not compressed or flexed. The compression and canopy pads84and90are wrapped in a durable vinyl covering97to form an integral structure. The vinyl covering97is preferably a PVC vinyl coated polyester having a weight of about 22 to 50 ounces per square yard. The covering97has a flap that extends to hide the backing plate82when installed.

The downwardly extending flap or curtain98is secured to and hangs from the outer end92of the forward extending canopy pad84. The upper end of the flap98is preferably joined to the outer end92of the canopy pad90via Velcro or other suitable form of securement. The flap98is made of a durable vinyl. The flap98has a height of about twelve inches and a lower end98aand extends about four inches into the bay opening projection15. A stiffening sheet99is attached to the flap70to ensure a proper seal with the top of the trailer during use.

As state above, the side seal assemblies40of the multi-seal dock seal30are suited for use with a conventional rigid header frame19as shown inFIG. 9. In this embodiment, the top seal assembly80is replaced by a conventional header frame19with a downwardly hanging front curtain, such as a header with a wood framed construction.

When installed, the multi-seal dock seal30extends along the two vertical sides12of the bay opening10, and preferably around the sides12and horizontal top13of the opening10as shown inFIGS. 1A-B. During use, both a continuous wipe seal100and a continuous compression seal105are formed with the trailer20to produce a continuous multi-seal110along the sides22of the trailer, and preferably around the sides22and roof24of the trailer as shown inFIGS. 3, 4A-B and5A-B. When the trailer20partially backs into the dock as inFIGS. 4B and 5B, the single-seal or wipe seal100is formed by the flex pads70and flap98. The flex pads70flexingly engage and seal against the side walls22of the trailer, to form a continuous wipe seal100along the side walls of the trailer, and when used with the top wipe seal flap98, combine to flexingly engage and seal around the sides walls22and roof24of the trailer to form a continuous wipe seal100around the sides and roof of the trailer. The flex pads70and flap98bend rearwardly to wipe along the sides and top walls22and24of the trailer. The higher density foam of the flexible wipe seal pads70and their extension pads60provide sufficient rigidity during their wiping action to from a continuous wipe seal100along the side walls22of the trailer20, and when used in conjunction with a canopy curtain, around the sides and roof22and24of the truck or trailer.

When the trailer20backs further into the dock as inFIGS. 4A and 5A, the rear end27of the side walls22and roof24of the trailer compressibly engages and seals against pads50to form continuous compression seals105along the rear end27of the sides22of the trailer, and when used with top compression pad84combine to form a continuous compression seal around the rear end27of the sides and top22and24of the trailer. The formation of the continuous wipe and compression seals100and105produces a continuous multi-seal110along the trailer side walls22, and around the trailer side walls and roof. However, should the trailer20fail to back completely into the dock as inFIGS. 4B and 5Bso that the compression seal105is not fully engaged or formed, then the multi-seal30still provides a continuous wipe seal100around the perimeter of the trailer to seal the loading bay opening10from weather and the environment. Similarly, should the trailer20fail to completely engage the wipe seal pads70and flap98to form a continuous wipe seal100, then the multi-seal30can still provides a continuous compression seal105along the side walls22, and preferably around the rear end27of the trailer20to seal the bay opening10from weather and the environment.

As shown inFIGS. 5A-C, the side wipe seal pad70has an inwardly extending length that is sufficiently long to extend into the door opening10the same distance as the side compression pad50. (FIG. 5C). The lengths of the side wipe seal pad70and side extension pad60are sized so that the side wipe seal pad70does not contact the front surface51of the side compression seal pad50when it is pushed back by the trailer20. (FIGS. 5A-B). Each side wipe seal pad70is positioned forward from its respective compression pad50just far enough to prevent it from contacting the compression pad when in wiping engagement with the trailer20. This prevents the side wipe pad70from being pinched between the rear end27of the trailer20and its respective compression pad50. To avoid unnecessary wind and snow loads, the lengths of the extension pad60and canopy pad90are kept to a minimum to achieve desired wipe pad70and top flap98lengths.

While this invention is susceptible to embodiments in many different forms, the drawings show and the specification describes preferred embodiments of the invention. It should be understood that the drawings and specification are to be considered an exemplification of the principles of the invention. They are not intended to limit the broad aspects of the invention to the embodiments illustrated. Various changes may be made and equivalents may be substituted without departing from the broader aspects of the invention.