Note: Descriptions are shown in the official language in which they were submitted.
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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.
to 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
2o . 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 proj ecting 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
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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
to 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
2o 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.
In 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.
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In 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.
io W 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
2o 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.
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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
l0 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
16.
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
3o 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 14 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
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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 adj acent the
rear lower
edge of vehicle 16. In 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.
to 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
15 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
20 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
25 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
3o 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.
35 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-
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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 4.3.
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' S2 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 susceptibleao 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,
3o 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 axe 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
PVC. The
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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
crushed 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
to 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.
Refernng 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 40 (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.
2o 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
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.
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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
1 o taller than pad 48. Also, pad 48 could have a section adj acent 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 corner
of dock
~~ 'shelter'~0': '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
2o 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 determined by reference to the claims, which follow.
We claim:
