WO2004013433A1

WO2004013433A1 - Seal for a loading dock bumper

Info

Publication number: WO2004013433A1
Application number: PCT/US2002/023723
Authority: WO
Inventors: Dave Hoffmann; Gary Borgerding
Original assignee: Rite-Hite Holding Corporation
Priority date: 2002-07-26
Filing date: 2002-07-26
Publication date: 2004-02-12
Also published as: US20050102929A1; CA2464411A1

Abstract

At a loading dock (10) for a truck (16), a compressible bumper seal (30) extends across the front face of a dock bumper (24) to seal an air gap between the bumper face and the rear of the truck (16).

Description

SEAL FOR A LOADING DOCK BUMPER

Background of the Invention

Field of the Invention

The subject invention generally pertains to loading docks, and more specifically to a device that helps seal an air gap that may exist between a rear surface of a vehicle and the front face of a bumper that is attached to the dock.

Description of Related Art

A typical loading dock of a building includes an exterior doorway with an elevated platform for loading and unloading vehicles, such as trucks and trailers. To compensate for height differences between the loading dock platform and an adjacent bed of a truck or trailer, many loading docks have a dock leveler. A typical dock leveler includes a deck, also known as a ramp or dockboard, which is pivotally hinged along its back edge to vary the height of its front edge. An extension plate, or lip, extends outward from the deck's front edge to span the gap between the rear of the truck bed and the front edge of the deck. The lip is usually moveable between a stored position to an extended, operative position. In the extended, operative position, the lip extends from the deck's front edge and rests upon the truck bed to form a bridge between the two. This allows personnel and material handling equipment to readily move on and off the vehicle during loading and unloading operations.

To protect the building and the dock leveler from direct vehicle impact, loading docks often include bumpers. Bumpers also help establish a predetermined minimum distance between the rear of the vehicle and the dock leveler, so the dock leveler can first raise and then lower its lip upon the rear of the vehicle. Bumpers are usually installed near the bottom of the doorway, adjacent either side of the dock leveler lip and protrude a few inches out from the face of the dock, where they can be abutted by the rear of the vehicle. To help block out rain, snow and outside air from entering the building through air gaps between the back of the vehicle and the exterior face of the building, usually either a dock seal or a dock shelter is installed around the perimeter of the doorway.

Dock shelters often have projecting members that protrude outwardly from the face of the building and run generally along the top and lateral sides of the doorway. From a protruding edge of the projecting members, a top extending member and two laterally extending members may extend inward and generally parallel to the building face to help seal against the truck's top and sides, respectively. The laterally extending members are often made of a fabric or flexible foam. Two inner bottom corners of the dock shelter at the lower back sides of the truck are often partially sealed by draft pads attached to the lower ends of the projecting members. The dock leveler lip resting upon the rear of the vehicle is often relied upon to seal most of the doorway's lower edge.

Typical dock seals comprise a resiliently compressible foam core protected by a fabric outer cover. They are usually mounted to the face of a building, along the top and both sides of the doorway. With dock seals, sealing is provided by backing the truck directly up against the seal. The seal then compressively conforms to the shape of the truck's rear edges. The foam core provides the necessary compliance and resilience to repeatedly conform to the shape of various trucks, while the outer cover protects the foam core from dirt, water and abrasion. As with dock shelters, dock seals also rely on the dock leveler lip to seal most of the doorway's lower edge.

With conventional dock seals and shelters, an air gap may still exist between the rear of the vehicle and the front face of the bumpers. This can occur when a vehicle backing into the dock "bounces off the bumpers or simply stops just short of reaching the bumpers. Such an air gap can be a few inches across and can allow a significant air draft into the building.

A gap can also exist between a bumper and the underside of a dock shelter or the underside of a dock seal. For dock seals, such a gap may be due horizontal or vertical displacement between the bumper and the portion of the dock seal that runs along the vertical edge of the doorway. For dock shelters, the gap can be due to horizontal or vertical displacement between the bumper and dock shelter' s draft pad.

Summary of the Invention

In some embodiments, a relatively soft bumper seal overlays the front face of loading dock bumper. In some embodiments, the bumper seal includes a foam core that is softer or more compressible than the bumper.

In some embodiments, the foam core is at least partially covered by a pliable, weather resistant cover.

In some embodiments, the weather resistant cover is protected by a tough slipcover that can be replaced when necessary. h some embodiments, the slipcover is stiffer than the weather resistant cover.

In some embodiments, a structure of flexible sheets provides a collapsible bumper seal that overlays the front face of a loading dock bumper. hi some embodiments, the flexible sheets comprise a plurality of tubes.

In some embodiments, the bumper seal is mounted adjacent to the bumper.

In some embodiments, the bumper seal is attached to a vertical face of a loading dock. In some embodiments, the bumper seal is attached directly to the bumper.

In some embodiments, the bumper seal comprises a face-sealing member and a side-sealing member, wherein the face-sealing member seals a gap between the bumper and the rear of a vehicle, and the side-sealing member seals a gap between the bumper and a lower portion of a dock seal or a dock shelter's draft pad. h some embodiments of bumper seal that include a compressible or collapsible core with a weather resistant cover and a semi-rigid slipcover over that, a protective semi-rigid sheet of^* material is inserted between the slipcover and the core to help evenly distribute vehicle-imparted forces across the core.

Brief Description of the Drawings

Figure 1 is a perspective view of a loading dock that includes a bumper seal. Figure 2 is similar to Figure 1, but showing a truck having backed into the dock.

Figure 3 is similar to Figure 1, but showing a bumper seal being installed over the face of a bumper, wherein the seal's slipcover is partially pealed back to show a mounting bracket.

Figure 4 is a cross-sectional view taken along line 4-4 of Figure 1. Figure 5 is similar to Figure 4, but with the vehicle pressing hard against the bumper.

Figure 6 is similar to Figure 5, but with the vehicle having moved slightly away from the bumper.

Figure 7 is a perspective view of a bumper seal's core. Figure 8 is a perspective view of the core of Figure 7 covered by a weather resistant cover.

Figure 9 is a perspective view of the core and cover of Figure 8 with the covered core being further covered by a tough slipcover.

Figure 10 is a perspective view of an uncovered bumper seal whose core is collapsible.

Figure 11 is similar to Figure 10, but with the bumper seal protected by a slipcover.

Figure 12 is a perspective view of another bumper seal with a collapsible core. Figure 13 is a schematic top view of one embodiment of a bumper seal that includes a face-sealing member and a side-sealing member.

Figure 14 is similar to Figure 8, but of another embodiment.

Figure 15 is similar to Figure 9, but of another embodiment. Figures 16, 17 and 18 correspond respectively to Figures 4, 5 and 6 and illustrate another embodiment where a bumper seal attaches directly to a bumper.

Figure 19 is a front view of a bumper seal that includes a side-sealing member for sealing a vertical gap.

Figure 20 is a front view of the bumper seal of Figure 19, but showing the side-sealing member sealing a horizontal gap.

Figure 21 is a similar to Figure 19, but showing the bumper seal sealing a vertical gap between a bumper and a dock shelter.

Figure 22 is similar to Figure 20, but showing the bumper seal sealing a horizontal gap between a bumper and a dock shelter.

Description of the Preferred Embodiment

Referring to Figures 1 and 2, a loading dock 10 comprises an elevated doorway 12 of a building 14. A vehicle 16, such, a truck or trailer, can move in a rearward direction 18 into dock 10 to load or unload cargo through doorway 12. In this example, a conventional dock leveler 20 with an extendible lip 22 is used to bridge the gap between the lower edge of doorway 12 and a lower rear edge of vehicle 1 6. To protect building 14 and dock leveler 20 from direct vehicle impact, loading dock 10 is provided with one or more shock-absorbing bumpers 24 that protrude about four to six inches out from a face 26 of the dock. Bumpers 24 also help establish a predetermined minimum distance between the vehicle's back edge 28 and the front of dock leveler 20, so dock leveler 20 can first lift and then lower lip 22 upon the bed of vehicle 16. Bumpers 24 can be installed near the bottom of doorway 12, adjacent either side of dock leveler lip 22, where the bumpers can be abutted by the rear of vehicle 16. Alternatively, bumpers 24 can be attached or coupled to dock leveler 20 and in some cases may even be movable between retracted and operative positions. To help block out rain, snow and outside air from entering building 14 through air gaps between the exterior face of building 1 and the upper and two side edges along the rear of vehicle 16, a dock seal 30 may be installed along the perimeter of doorway 12. For example, dock seal 30 includes two vertical side pads 32 and a head pad 34, which compressively conform to the shape of a vehicle's rear edges as the vehicle backs up against pads 32 and 34. It should be appreciated, however, that the use of a dock shelter instead of a dock seal is also well within the scope of the invention. Regardless of whether a dock shelter or dock seal is used, lip 22 extending out over the bed of truck 16 can be used to help cover the gap adjacent the rear lower edge of vehicle 16. i cases where a loading dock does not have a dock leveler, a lower pad may be installed along the lower edge of the doorway to help seal gaps in that area. The subject invention does not have to be used in combination with a dock leveler. Sometimes, vehicle 16 may stop without its rear edge 28 tightly up against a front face 34 of the bumpers. For instance, vehicle 16 may "bounce off the bumpers before actually stopping. This can create an air gap between the vehicle's rear edge 28 and the front face of the bumpers.

To help seal such an air gap, a bumper seal 36 having a compressible or collapsible face-sealing member 38 can be installed in front of the bumpers, as shown in Figures 3 and 13. The actual method of mounting can vary, as face-sealing member 38 can be mounted directly to the bumper, or face-sealing member 38 may be associated with additional mounting structure. For example, face-sealing member 38 itself can comprise an entire bumper seal as depicted in Figures 16-18, or face sealing member 38 may be part of the bumper seal 36 that also includes a side-sealing member 51 (see Figure 13), wherein side-sealing member 51 helps in the mounting of face member 38, as depicted in Figures 7-9. A rear section 35 of seal 36 engages front face 34 of bumper 24, a front section 37 is adapted to be engaged by vehicle 16, and a central section 39 (which is more compressible than bumper 24) is between sections 35 and 37. Then, if vehicle 16 backs into dock 10 and bounces off bumpers 24, bumper seal 36 can respond in the sequence shown in Figures 4, 5 and 6. In Figure 4, the face-sealing member 38 of bumper seal 36 is in a normally expanded state as vehicle 16 backs toward bumper 24. In Figure 5, vehicle 16 tightly compresses face- sealing member 38 of seal 36 between the vehicle's rear edge 28 and the bumper's front face 34. The impact of vehicle 16 is transmitted to bumper 24, which may compress bumper 24 a certain amount as the bumper absorbs at least some of the impact. However, face-sealing member 38 is softer or more compressible than bumper 24, so seal 36 is compressed to a much greater extent as vehicle 16 tightly compresses seal 36 between the vehicle's rear edge 28 and the bumper's front face 34. If vehicle 16 bounces away from bumper 24, as shown in Figure 6, seal 36 may expand to fill the gap between bumper 24 and vehicle 16.

To mount face-sealing member 38, seal 36 can be constructed as shown in Figures 7, 8 and 9 to include a side-sealing member 51 that also mounts the face- sealing member adjacent bumper 24. Figure 7 shows bumper seal 36 having a compressible core 40 adjacent a mounting plate, such as a wood backer 43. Backer 43 provides structure that enables a bracket 42 (Figure 3) to attach seal 36 to the face of building 14 and to thus properly locate face-sealing member 38 over the front face of bumper 24. In some embodiments, core 40 comprises one or more compressible foam pads, such as pads 44, 46 and 48. Pad 44 helps seal between backer 43 and a bumper mounting bracket 50 (which connects bumper 24 to building 14, as shown in Figure 4), pad 48 helps seal between the bumper's front face 34 and the vehicle' s rear edge 28, and pad 46 helps ensure that the vehicle's impact is transmitted more to bumper 24 than to backer 43.

To help protect core 40 from dirt and weather, or to help hold various parts of core 40 together, core 40 can be at least partially covered by a weather resistant cover 52, as shown in Figure 8. The term, "weather resistant" refers to any material that provides at least some shield against wind or rain. Cover 52 may consist of a pliable vinyl or some other type of fabric that is sufficiently pliable to allow core 40 to be compressed by vehicle 16. Cover 52 preferably includes some venting feature (e.g., a round hole at the bottom of bumper seal 36) that allows air to enter and escape from within cover 52 as core 40 is compressed or decompressed.

To help protect cover 52 from being cut, excessively worn or otherwise damaged by the impact of vehicle 16, a tough slipcover 54 extends over areas of cover 52 that are most susceptible to damage. Slipcover 54 can be made of PVC or a similar material that is tougher and less pliable than cover 52. In some embodiments, slipcover 54 is made of a polyethylene, cross-linked, closed-cell foam that is formed, compressed and heated to provide a desired density and rigidity. In some cases, the rigidity of slipcover 52 may vary, with certain areas of slipcover 52 being more rigid than others. For example, front section 37 may be more rigid than other areas to help evenly distribute the compressive forces that vehicle 16 may exert against core 40. Preferably, slipcover 54 is readily replaceable by wrapping the slipcover around core 40 and cover 52, as shown in Figure 9. A looped end 56 of slipcover 54 can be sewn, bonded, welded or otherwise connected to itself at a seam 58, and another end 60 of the slipcover can be stapled, screwed, hooked or otherwise attached to backer 43. End 60 can be clamped between bracket 42 and backer 43, or a part 62 of end 60 can overlay bracket 42 as shown in Figure 4. Slipcover 54 can be replaced (or switched from a righthand bumper seal to a lefthand bumper seal) by detaching end 60 from backer 43 and slipping looped end 56 off core 40.

Alternate, but similar, embodiments of a bumper seal are shown in Figures 10, 11 and 12. In Figures 10 and 11, a bumper seal 64 includes a collapsible core 66 having a collapsible structure made of a flexible sheet of material, such as PNC. The- actual structure can be of various shapes and configurations. For example, the flexible sheets of material can be in the form of tubes 68 that resiliently flatten out upon being cru-shed between bumper 24 and the vehicle's rear edge 28. Accordingly, the volume of core 66 that extends inward (to the left in the sense of Figure 10) from pads 44 and 46 forms a face-sealing member 38' according to this embodiment. In some cases, backer 43 and pads 44 and 46 can be protected by a cover 68 similar to cover 52, and slipcover 54 can help protect core 66.

Figure 12 shows a bumper seal 70 that includes a collapsible core 72 made of flexible sheets of material that form a series of foldable boxes. The boxes resiliently fold into a flattened shape upon vehicle 16 backing up against bumper 24. Seal 70 may be provided with cover 68 and/or slipcover 54.

Referring to Figures 14 and 15, to help evenly distribute the compressive forces that vehicle 16 may exert against core 40 (Figure 7), a protective insert 80 can be installed in front of a bumper seal's core. Figure 14 is the same as Figure 15, but with slipcover 54 removed. In this example, a bumper seal 36' includes insert 80 installed between slipcover 54 and core 4O (e.g., between slipcover 54 and cover 52). Insert 80 can be made of any semi-rigid sheet of material, such as HDPE (high density polyethylene). Insert 80 can be held in place by any suitable manner, such as by sewing, glueing, etc. Just as Figures 4, 5 and 6 illustrate in sequence the operation of bumper seal

36, respective Figures 16, 17 and 18 illustrate the structure and an operational sequence of a bumper seal 82. Bumper seal 82 comprises a face-sealing member 84 that includes a compressible or collapsible core 98 with a pliable cover 100. Face- sealing member 84 attaches directly to a bumper 86 without the use of side-sealing ^l member 51 as in the previous embodiments. It should be appreciated by those skilled in the art that the actual structure of bumper 86 and bumper seal 82 could vary widely without departing from the basic concept of mounting a face-sealing member directly to a bumper. Nonetheless, in this particular example, bumper 86 comprises a hard rubber compressible core 88 contained within a telescoping metal housing. The housing includes one piece 90 that can move relative to another piece 92, so the two pieces 90 and 92 can compress core 88 under an impact of vehicle 16. Bumper seal 82 can be attached to bumper 86 in any suitable manner to properly position face- sealing member 84 relative to the front face of bumper 86. For example, seal 82 may include straps or material 94 that can attach to bumper 86 in any one of various ways including, but not limited to, hooking onto bumper 86, wrapping around bumper 86, being fastened with screws, adhesive, etc. The various means of attachment are schematically represented by element 96. In another embodiment, shown in Figures 19 and 20, a bumper seal 102 comprises a side-sealing member 104 that mounts a face-sealing member 105 in proper position relative to bumper 24, and that also helps seal a gap between bumper 24 (shown in phantom behind seal 102) and vertical side pad 32 of dock seal 30, wherein side pad 32 is just one example of a side seal disposed along a lateral edge of a doorway. Side-sealing member 104 is shown sealing a vertical gap 106 in Figure 19 and shown sealing a horizontal gap 108 in Figure 20. To achieve this capability, side- sealing member 104 has a greater vertical extent than face-sealing member 102. For example, one could modify the embodiment of Figure 7 so that pads 44 and 46 were taller than pad 48. Also, pad 48 could have a section adjacent pad 46 of a greater height as well. One would preferably make backer 43 taller as well. This is depicted schematically in Figures 19 and 21.

Figures 21 and 22 are similar to Figures 19 and 20 respectively. However, instead of dock seal 30, the embodiment of Figures 21 and 22 have a dock shelter 30' that includes a draft pad 110. Draft pad 110 helps seal a lower inner comer of dock shelter 30'. Further details of sample dock shelters and draft pads are disclosed in U. S. Patents 6,014,844; 4,885,881; and 3,792,559, which are specifically incorporated by reference herein. For dock shelter 30', bumper seal 102 includes a face-sealing member 105 for sealing the front face of the bumper and a side-sealing member 104 for mounting member 105 and that helps seal a gap between bumper 24 and draft pad 110 of vertical side seal 32', wherein vertical side seal 32' is just one example of a side seal disposed along a lateral edge of a doorway. Side-sealing member 104 is shown sealing a vertical gap 106' in Figure 21 and shown sealing a horizontal gap 108' in Figure 22. Although the invention is described with respect to a preferred embodiment, modifications thereto will be apparent to those skilled in the art. Therefore, the scope of the invention is to be detennined by reference to the claims, which follow. We claim:

Claims

1. A bumper assembly for use at a loading dock for receiving an impact from a vehicle moving in a rearward direction, comprising: a bumper installed at the loading dock and including a front face that faces away from the rearward direction, wherein the bumper is compressible to at least partially absorb the impact; and a bumper seal extending across the front face of the bumper and being adapted to be engaged by the vehicle, wherein the bumper seal is more compressible than the bumper.

2. The bumper assembly of claim 1 , wherein the bumper seal includes a foam core.

3. The bumper assembly of claim 2, further comprising a weather resistant cover overlaying the foam core.

4. The bumper assembly of claim 3 , further comprising a slipcover overlaying the weather resistant cover.

5. The bumper assembly of claim 4, further comprising a protective insert disposed between the slipcover and the foam core.

6. The bumper assembly of claim 5, wherein the protective insert is sandwiched between the slipcover and the weather resistant cover.

7. The bumper assembly of claim 5, wherein the protective insert is a sheet of material that less pliable than the weather resistant cover.

8. The bumper assembly of claim 4, wherein the weather resistant cover is more pliable than the slipcover.

9. The bumper assembly of claim 1, wherein the bumper seal comprises a collapsible core that includes a flexible sheet of material.

10. The bumper assembly of claim 9, wherein the flexible sheet of material is in the shape of a tube.

11. The bumper assembly of claim 9, further comprising a slipcover overlaying the collapsible core.

12. The bumper assembly of claim 1, wherein the bumper seal includes point of attachment for attaching the bumper seal at the loading dock, wherein the point of attachment is at a position that is further rearward than the front face of the bumper.

13. The bumper assembly of claim 1 , wherein the bumper seal is attached to the bumper.

14. A bumper seal for sealing a gap between a front face of a bumper and a rear surface of a vehicle, wherein the bumper is installed at a loading dock and the front face is adapted to receive an impact created by the vehicle, the bumper seal comprising: a rear section extending across the front face of the bumper and being adapted to engage the front face of the bumper; a front section connected to the rear section and adapted to be engaged by the rear surface of the vehicle; and a central section interposed between the front section and the rear section, wherein the central section is more compressible than the bumper.

15. The bumper seal of claim 14, wherein the central section includes a foam core.

16. The bumper seal of claim 14, further comprising a weather resistant cover overlaying at least one of the rear section, the front section, and the central section.

17. The bumper seal of claim 16, further comprising a slipcover overlaying the weather resistant cover.

18. The bumper assembly of claim 17, further comprising a protective insert disposed between the slipcover and the foam core.

19. The bumper assembly of claim 18, wherein the protective insert is sandwiched between the slipcover and the weather resistant cover.

20. The bumper assembly of claim 18, wherein the protective insert is a sheet of material that less pliable than the weather resistant cover.

21. The bumper seal of claim 17, wherein the weather resistant cover is more pliable than the slipcover.

22. The bumper seal of claim 14, wherein the bumper seal comprises a collapsible core that includes a flexible sheet of material.

23. The bumper seal of claim 22, wherein the flexible sheet of material is in the shape of a tube.

24. The bumper seal of claim 22, further comprising a slipcover overlaying the collapsible core.

25. The bumper seal of claim 14, wherein the bumper seal includes point of attachment for attaching the bumper seal at the loading dock, wherein the loading dock has a dock face that is closer to the point of attachment than the front face of the bumper.

26. A method of at least partially sealing a gap between a front face of a compressible bumper and a rear surface of a vehicle, comprising: installing a bumper seal so that the bumper seal overlays the front face of the compressible bumper; and compressing the bumper seal between the front face of the compressible bumper and the rear surface of the vehicle.

27. The method of claim 26, compressing the bumper, but to a lesser extent than that which the bumper seal is compressed.

28. The method of claim 26, further comprising attaching the bumper seal to the compressible bumper.

29. A sealing assembly for use at a doorway of a loading dock for a vehicle, the sealing assembly comprising: a side seal disposed along a lateral edge of the doorway; a bumper having a front face for receiving an impact of the vehicle, wherein the bumper is spaced apart from the side seal to define a gap therebetween; and a side-sealing member bridging the gap by engaging the bumper and the side seal.

30. The sealing assembly of claim 29, wherein the gap is a vertical gap.

31. The sealing assembly of claim 29, wherein the gap is a horizontal gap.

32. The sealing assembly of claim 29, further comprising a face-sealing member extending from the side-sealing member and overlaying the front face of the bumper, wherein the face-sealing member is more compressible than the bumper.

33. The sealing assembly of claim 29, wherein the side seal includes a draft pad near the bottom of the side seal.