U.S. patent application number 09/780931 was filed with the patent office on 2002-08-15 for loading dock shelter with semi-rigid curtains.
Invention is credited to Borgerding, Gary, Miller, Jason D., Schmidt, Timothy J..
Application Number | 20020110423 09/780931 |
Document ID | / |
Family ID | 25121129 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020110423 |
Kind Code |
A1 |
Miller, Jason D. ; et
al. |
August 15, 2002 |
Loading dock shelter with semi-rigid curtains
Abstract
In order to provide a loading dock shelter with an effective
seal, the shelter is provided with a side curtain that is
semi-rigid. The relative stiffness of the curtain allows it to be
supported along a vertical edge, while a distal vertical edge of
the curtain can be cantilevered for sealing against the side of a
truck. The curtain has sufficient flexibility and resilience to at
least partially seal against the truck without having to rely on
compressible foam. In some cases, the semi-rigid curtain is
attached to a side frame by way of a sliding connection that allows
for differences in thermal expansion between the curtain and the
frame. A relatively pliable corner seal helps seal a gap between
the side curtain and an adjacent head curtain.
Inventors: |
Miller, Jason D.; (Sherrill,
IA) ; Borgerding, Gary; (Holy Cross, IA) ;
Schmidt, Timothy J.; (Dubuque, IA) |
Correspondence
Address: |
James A. Flight, Esq.
Marshall, O'Toole, Gerstein, Murray & Borun
233 South Wacker Drive
Chicago
IL
60606-6402
US
|
Family ID: |
25121129 |
Appl. No.: |
09/780931 |
Filed: |
February 9, 2001 |
Current U.S.
Class: |
405/110 |
Current CPC
Class: |
B65G 69/008
20130101 |
Class at
Publication: |
405/110 |
International
Class: |
E02B 007/14 |
Claims
I claim:
1. A dock shelter adapted to provide at least a partial seal
between a vehicle and a wall of a building, comprising: a side
frame mountable to the wall and being vertically elongated; a side
curtain having a proximal edge coupled to the side frame and a
distal edge adapted to engage the vehicle; and a sliding connection
that couples the proximal edge to the frame, wherein the sliding
connection allows vertical thermal expansion of the side curtain
relative to the side frame.
2. The dock shelter of claim 1 wherein the sliding connection
comprises at least one vertical slot in the side curtain and at
least one vertically fixed post fixed relative to the side frame
and received within the at least one slot.
3. The dock shelter of claim 2, further comprising a plurality of
metal stays attached to the side curtain to help bias the side
curtain to the standby position.
4. The dock shelter of claim 2, wherein the distal edge curves
about a second vertical axis.
5. The dock shelter of claim 1, wherein the proximal edge has a
plurality of vertically elongated slots that facilitate the sliding
connection.
6. The dock shelter of claim 5, further comprising a plurality of
fasteners extending through a plurality of bushings, which in turn
extend through the plurality of elongated slots, wherein the
plurality of bushings each have a length that helps prevent the
plurality of fasteners from being over tightened against the side
curtain.
7. The dock shelter of claim 1, further comprising: a head frame
mountable to the wall and being horizontally elongated; a head
curtain suspended from the head frame; and a corner curtain
bridging a gap between the head curtain and the side curtain.
8. The dock shelter of claim 7, wherein the corner curtain is more
flexible than the side curtain and the head curtain.
9. The dock shelter of claim 7, wherein the corner curtain includes
a first portion that overlaps the side curtain and a second portion
that overlaps the head curtain such that the side curtain is closer
to the wall than the first portion but the second portion is closer
to the wall than the head curtain.
10. A dock shelter adapted to provide at least a partial seal
between a vehicle and a wall of a building, comprising: a side
frame mountable to the wall and being vertically elongated; a side
curtain having a proximal edge coupled to the side frame and a
distal edge adapted to engage the vehicle; and a first sliding
connection that couples the proximal edge to the frame, wherein the
first sliding connection allows vertical thermal expansion of the
side curtain relative to the side frame; a head frame mountable to
the wall and being horizontally elongated; a head curtain suspended
from the head frame; and a second sliding connection that couples
the head curtain to the head frame, wherein the second sliding
connection allows horizontal thermal expansion of the head curtain
relative to the head frame.
11. The dock shelter of claim 10, wherein the distal edge curves
about a vertical axis.
12. The dock shelter of claim 10, further comprising a corner
curtain bridging a gap between the head curtain and the side
curtain.
13. The dock shelter of claim 12, wherein the corner curtain is
more flexible than the head curtain and the side curtain.
14. The dock shelter of claim 10, wherein the first sliding
connection comprises at least one vertical slot in the side curtain
and at least one vertically fixed post fixed relative to the side
frame and received within the at least one slot.
15. A dock shelter adapted to provide at least a partial seal
between a vehicle and a wall of a building, comprising: a side
frame mountable to the wall and being vertically elongated; a side
curtain having a proximal edge coupled to the side frame and a
distal edge adapted to engage the vehicle; a head frame mountable
to the wall and being horizontally elongated; a head curtain
suspended from the head frame; and a corner curtain bridging a gap
between the head curtain and the side curtain, wherein the corner
curtain is more pliable than the side curtain.
16. The dock shelter of claim 15, wherein the corner curtain is
more pliable than the head curtain.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject invention generally pertains to loading dock
shelters and more specifically to an enhanced sealing member for
such a shelter.
[0003] 2. Description of Related Art
[0004] Trucks and other vehicles typically back up against a
loading dock or doorway of a building to facilitate loading and
unloading of the vehicle's cargo. Often a dock shelter is installed
around the doorway to help shelter the area between the perimeter
of the doorway and the rear of the vehicle. If left unsheltered,
air gaps between the outer wall of the building and the back of the
vehicle might allow the outside weather to increase the building's
heating or cooling load, allow rain and snow to enter the interior
of the building, or simply subject the inside dock workers to an
uncomfortable draft while they service the vehicle.
[0005] Dock shelters usually include a framework that extends one
to three feet outward from the face of the building wall. In some
cases, pliable curtains hang from the framework and are situated to
drape over the top and either side of a vehicle parked under the
shelter. Such curtains are generally not self-supporting and tend
to be rather limp, which can create a poor appearance. Lateral
reinforcement of such curtains may be provided by including stays
or other stiffeners. While this may improve appearance and/or
sealing characteristics, it also requires additional components and
labor to assemble. Further, while shelters may be adequate in
milder climates, additional or alternate sealing may be required
where weather conditions are more severe.
[0006] Thus, some loading docks are provided with dock seals made
of a resiliently compressible foam pad. As a truck backs into the
dock and against the seal, the foam pad compresses to conform to
the contour of the rear edges of the truck. Although effective,
such seals can be expensive, as they comprise an assembly of
components. The foam pad usually needs a tough outer cover to
protect the pad from wear and to prevent the pad from absorbing
water and dirt. A cover should be tough to resist wear, yet pliable
to allow the foam pad to compress. Unfortunately, some of the
toughest materials are not very pliable, and vise versa. So, a
compromise is often needed in selecting a cover with an optimum
combination of toughness and pliability.
[0007] Consequently, a need exists for a dock shelter that provides
a more positive seal than current shelters, yet is more economical
than conventional dock seals.
SUMMARY OF THE INVENTION
[0008] In order to provide a dock shelter with a more effective
seal, a dock shelter is provided with a side curtain that is
semi-rigid. The relative stiffness of the curtain allows it to be
supported along a vertical edge, while a distal vertical edge of
the curtain can be cantilevered for sealing against the side of a
truck. The curtain has sufficient flexibility and resilience to at
least partially seal against the side of a truck without having to
rely on compressible foam. In some cases, the semi-rigid curtain is
attached to a side frame by way of a sliding connection that allows
for differences in thermal expansion between the curtain and the
frame.
[0009] In some embodiments, a dock shelter is provided with a head
curtain attached to a head frame by way of a sliding connection
that allows for differences in thermal expansion between the head
frame and the head curtain.
[0010] In some embodiments, a corner curtain covers the gap between
a side curtain and a head curtain with the corner curtain being
more pliable than the side curtain or the head curtain.
[0011] In some embodiments, a sliding connection between a side
curtain and a side frame is created by providing the curtain with
vertical slots used for anchoring the curtain to the frame.
[0012] In some embodiments, the dock shelter includes a vertically
elongated side curtain of sufficient rigidity to be cantilevered
from an anchored vertical edge out to a distal vertical edge.
[0013] In some embodiments, the distal vertical edge of a side
curtain is curved about a vertical axis to help prevent the edge
from catching on a vehicle as the vehicle leaves the dock
shelter.
[0014] In some embodiments, metal stays provide a plastic side
curtain with greater rigidity and resilience.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a front view of one embodiment of a dock shelter
with a semi-rigid side curtain.
[0016] FIG. 2 is a side view of the dock shelter of FIG. 1 showing
a vehicle backing into the shelter.
[0017] FIG. 3 is the same as FIG. 2, but showing the vehicle having
already backed into the shelter.
[0018] FIG. 4 is a cross-sectional view taken along line 4-4 of
FIG. 3.
[0019] FIG. 5 is a cross-sectional view taken along line 5-5 of
FIG. 3.
[0020] FIG. 6 is a cross-sectional view taken along line 6-6 of
FIG. 1.
[0021] FIG. 7 is a cross-sectional view taken along line 7-7 of
FIG. 6.
[0022] FIG. 8 is a cross-sectional view similar to FIG. 6, but of
another embodiment.
[0023] FIG. 9 is a cross-sectional view similar to FIG. 6, but of
another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Referring to FIGS. 1-3, a dock shelter 10 installed around a
doorway 12 of a loading dock 14 includes semi-rigid side curtains
16 and 18 that help provide a weather seal between the rear sides
of a vehicle 20 and a wall 22 of a building. To help seal along a
rear upper surface of vehicle 20, a head curtain 24 (similar to
side curtains 16 and 18 or of another design) can be installed
along an upper portion of dock shelter 10.
[0025] To support the curtains, shelter 10 includes a frame 26
comprising a head frame 28, a right side frame 30 and a left side
frame 32 that respectively support curtains 16, 18 and 24. Frame 26
attaches to wall 22 and supports the curtains in an offset
relationship to the face of wall 22. The offset relationship allows
vehicle 20 to back into shelter 10 and underneath head frame 28. As
vehicle 20 backs into shelter 10 and against bumpers 30 (i.e.,
moves from the position of FIGS. 2 and 4 to that of FIGS. 3 and 5),
the sides and top of vehicle 20, being larger than the inner
dimensions of shelter 10, deflect the inner edges of curtains 16,
18 and 24 backward and inward. The inner edges of the curtains thus
provide a sliding seal against the rear sides and roof of vehicle
20.
[0026] To create the sliding seal, curtains 16, 18 and 24 can be
moved from their standby positions of FIGS. 1, 2 and 4 to their
operative sealing positions of FIGS. 3 and 5, as vehicle 20 backs
into shelter 10. Although such curtain movement can be provided by
using hinges to attach the curtains to frame 26, a preferred
approach is to make curtains 16, 18 and 24 of a material having
sufficient flexibility to resiliently bend without the use of
hinges. However, the curtain material preferably still has
sufficient rigidity to allow left side curtain 16 to be
cantilevered from a proximal edge 36 (attached to side frame 32) to
a distal edge 38 (adapted to slidingly engage vehicle 20). The same
applies to right side curtain 18. Head curtain 24, as mentioned
earlier, can be of a similar construction or of another design
entirely. For the sake of simplicity, dock shelter 10 will be
described primarily with reference to left side curtain 16, with
right side curtain 18 and head curtain 24 having similar
features.
[0027] In some embodiments, side curtain 16 is made of 1/8-inch
thick high molecular weight polyethylene. Although other materials
and thickness can be used, this material in particular provides
several benefits. The relatively high density and other properties
of high molecular weight polyethylene makes it more resistant to
water, dirt and abrasion than many foam materials, and thus the
material does not require a protective cover. The rigidity of
polyethylene not only provides a neat, sag-free appearance, but
also allows side curtain 16 to be cantilevered from proximal edge
36, rather than being suspended from its top edge. Supporting
curtain 16 from the side allows distal edge 38 more freedom of
movement, especially near the top of curtain 16, thus distal edge
38 can effectively seal against vehicle 20 over a broader range of
curtain deflection.
[0028] A curtain made of polyethylene alone may have sufficient
resilience to return from its operative position to its standby
position, especially if gravity urges the curtain to its standby
position, as is the case with head curtain 24. Nonetheless, side
curtain 16 may include several spring-steel stays 40 that improve
the curtain's overall resilience. Stays 40 can be attached to side
curtain 16 by any one of a variety of fasteners 42 including, but
not limited to, screws or rivets. Fasteners 42 are preferably
attached at opposite ends of each stay 40 to allow a central
portion of stay 40 to bend away from the plastic portion of curtain
16 as curtain 16 deflects about a vertical axis 44 (FIG. 5).
[0029] To smoothed the movement of side curtain 16 as a departing
vehicle allows curtain 16 to return to its standby position, distal
edge 38 is curved about a vertical axis 46, as shown in FIG. 4.
With distal edge 38 being curved rather than sharp and straight,
distal edge 38 is less likely to catch on the side of vehicle 20 as
vehicle 20 moves out from within dock shelter 10.
[0030] In some cases, side frame 32 and side curtain 16 have
different coefficients of thermal expansion. For instance, curtain
16 being made of polyethylene has a greater coefficient of thermal
expansion than a side frame being made of wood. To accommodate this
difference, a sliding connection 48 can be used to attach side
curtain 16 to side frame 32, as shown in FIGS. 1, 6 and 7. For
example, sliding connection 48 can be provided by screws 50
protruding through elongated slots 52 in curtain 16 and screwing
into side frame 32. The shank of screws 50 form vertically fixed
posts which extend into the elongated slots 52. One will appreciate
that other vertically fixed posts could achieve the same
function--such as posts formed in the side frame or otherwise
affixed thereto. In the case of screws 50, they serve the
additional advantageous function of limiting movement of the
curtain away from the wall due to the presence of the screw heads.
A stand-off bushing 54 can be added to help prevent the head of
screw 50 from being over tightened against curtain 16. If bushing
54 is used, the shank of screw 50 fits through bushing 54, and the
bushing is a part of the vertically fixed post as a sliding fit is
provided between an outer diameter of bushing 54 and the width of
slot 52. For the illustrated dock shelter, side curtain 16 includes
one point of attachment 56 that is relatively fixed, rather than
being a sliding connection. The fixed point ensures that any
expansion of side curtain 16 will be from that point. In other
words, with point 56 being near the top of side curtain 16, the
bottom of curtain 16 will move more than the top, as curtain 16
expands and contracts vertically. Alternatively, the curtain
adjacent point 56 could have a slot as well, but having a smaller
vertical extent than the other slots and positioned such that the
screw or vertically fixed post would normally be disposed at the
top of that slot.
[0031] FIG. 8 illustrates another example of a sliding connection
48'. Here, a sliding fit exists between slot 52 and screw 50;
however, an angle member 58 attached to a side frame 32' prevents
the head of screw 50 from being tightened against curtain 16. Thus,
bushing 54 can be eliminated.
[0032] In another example of a sliding connection 48", shown in
FIG. 9, a side curtain 16' includes a ridge 60 running along a
proximal edge 36' of curtain 16'. An angle member 62 with an added
lip 64 then captures ridge 60 to limit the curtain's sideways
movement (i.e., perpendicular to the length of proximal edge 36').
Thus, ridge 60 and angle member 62 inhibit curtain 16 from
completely separating from a side frame 32" and member 62. However,
angle member 62 provides ridge 60 with enough clearance to allow
some sliding movement between curtain 16' and frame 32" for thermal
expansion in a direction parallel to ridge 60. Ridge 60 can be an
integral extension of curtain 16' or can be an added piece attached
using an adhesive or a mechanical fastener. A mechanical stop, such
as a fastener or some other obstruction, may be added to limit how
far ridge 60 can slide within angle member 62.
[0033] To help cover a gap 64 between side curtain 16 and head
curtain 24, a corner curtain 66 can be installed at each upper
corner of dock shelter 10. Comer curtain 66 can be especially
useful, as gap 64 increases in size as the other curtains deflect
from their standby positions to their operative positions. As gap
64 widens, its shape changes significantly with its defining edges
being distorted three-dimensionally. To maintain gap 64 covered
under such distortion, corner seal 66 overlaps both head curtain 24
and side curtain 16. Also, corner curtain 66 is preferably more
pliable than curtains 16 and 24 to effectively conform to the
changing shape of gap 64. In some embodiments, corner curtain 66 is
a relatively lightweight vinyl attached to frame 26, such that
corner curtain 66 is in front of side curtain 16 and behind head
curtain 24, or conversely, in front of head curtain 24 and behind
side curtain 16.
[0034] Although the invention is described with reference to a
presently preferred embodiment, it should be appreciated by those
skilled in the art that various modifications are well within the
scope of the invention. Therefore, the scope of the invention is to
be determined by reference to the claims that follow.
* * * * *