U.S. patent application number 12/177514 was filed with the patent office on 2010-01-28 for dock leveler insulation.
This patent application is currently assigned to DL Manufacturing. Invention is credited to David Martini, Donald L. Metz.
Application Number | 20100017976 12/177514 |
Document ID | / |
Family ID | 41567303 |
Filed Date | 2010-01-28 |
United States Patent
Application |
20100017976 |
Kind Code |
A1 |
Metz; Donald L. ; et
al. |
January 28, 2010 |
DOCK LEVELER INSULATION
Abstract
The bottom surface of a dock leveler is insulated by attaching
sheets of insulative material between adjacent support beams.
Attachment is by way of magnet attached to the bottom surface of
the deck to hold downwardly projecting spikes that penetrate the
insulative material, with a self locking washer then being placed
over the spike in order to secure the sheet of material in place.
Installation with variable widths between adjacent support beams is
facilitated by pre-perforating the sheets of insulative material
along longitudinal lines to thereby allow easy separation and width
adjustment to match the variable widths between the support
beams.
Inventors: |
Metz; Donald L.; (Kirkville,
NY) ; Martini; David; (Liverpool, NY) |
Correspondence
Address: |
MARJAMA MULDOON BLASIAK & SULLIVAN LLP
250 SOUTH CLINTON STREET, SUITE 300
SYRACUSE
NY
13202
US
|
Assignee: |
DL Manufacturing
North Syracuse
NY
|
Family ID: |
41567303 |
Appl. No.: |
12/177514 |
Filed: |
July 22, 2008 |
Current U.S.
Class: |
14/69.5 |
Current CPC
Class: |
B65G 69/287
20130101 |
Class at
Publication: |
14/69.5 |
International
Class: |
E01D 1/00 20060101
E01D001/00 |
Claims
1. A method of thermally insulating the deck of a dock leveler
having a plurality of transversely spaced support beams extending
longitudinally along its bottom surface, comprising the steps of:
providing a sheet of insulative material having a width that is
greater than the distance between adjacent support beams;
longitudinally perforating said sheets in discontinuous laterally
spaced lines; measuring the distance between adjacent support beams
and tearing off, along a line of perforations, a portion of said
sheet that is substantially equal in width to the distance between
adjacent support beams; and securing said portion to a bottom
surface of the deck between adjacent support beams.
2. A method as set forth in claim 1 wherein said securing step
includes the attachment of a plurality of magnets to the bottom
surface of said deck.
3. A method as set forth in claim 1 wherein said securing step
includes the step of piercing the sheet of insulative material with
a plurality of spikes that extend downwardly from the bottom
surface of the deck.
4. A method as set forth in claim 3 wherein said securing step
includes the step of installing a plate over the ends of each of
the spikes and the insulative sheet in order to secure the
insulative sheet in place.
5. A method as set forth in claim 1 and including a further step of
attaching a vinyl sheet to one side of said sheet of insulative
material.
6. A method as set forth in claim 5 wherein said vinyl sheet is
attached to said sheet of insulative material by way of a glue.
7. A method as set forth in claim 5 wherein said vinyl sheet is
attached to the side of said sheet of insulative material that is
away from the side which is adjacent to said plate.
8. A method as set forth in claim 5 and including the step of,
simultaneous with a step of tearing off a portion of said sheet,
cutting said vinyl sheet along a line of perforation.
9. An insulative cover for a bottom surface of a dock leveler
having a plurality of transversely spaced support beams extending
longitudinally along its bottom surface, comprising: a sheet of
insulative material placed between each pair of adjacent support
beams; a plurality of spikes attached to the bottom surface of said
deck, between adjacent support beams and extending downwardly to
penetrate said sheet of insulative material; and a fastener secured
over the ends of each of said spikes and the insulative material to
secure the sheet of insulative material in place.
10. A cover as set forth in claim 9 wherein said plurality of
spikes are secured to said bottom surface by way of magnets.
11. A cover as set forth in claim 9 wherein said fasteners comprise
perforated plates that are placed over said spikes to act as a self
locking washer.
12. A cover as set forth in claim 9 and including a vinyl sheet
that is attached to one side of said sheet of insulative
material.
13. A cover as set forth in claim 12 wherein said vinyl sheet is
attached to said sheet of insulative material by a glue.
14. A cover as set forth in claim 12 wherein said vinyl sheet is
attached to the side of said sheet of insulative material which is
opposite the side which is placed against the bottom surface of the
deck.
Description
TECHNICAL FIELD
[0001] This invention relates generally to dock levelers and, more
particularly, to a method and apparatus for insulating the bottom
surface thereof.
BACKGROUND OF THE INVENTION
[0002] Dock levelers are used to compensate for height differences
between a dock platform and the bed of a parked vehicle to permit
forklift trucks and personnel to readily move on and off the
vehicle during loading and unloading operations. A typical dock
leveler is mounted within a pit and has a deck pivotally connected
at its rear edge to a frame mounted within the pit for varying the
height of the dock leveler in order to compensate for the height
differences. An extension plate or lip is typically pivotally
connected to the front edge of the deck for spanning the distance
between the rear end of the vehicle bed and the outer front end of
the deck and permitting forklift trucks and personnel to safely
load and unload the truck without difficulty.
[0003] The deck is adapted to pivot between downwardly inclined or
lowered positions, a horizontal or level position, and upwardly
inclined or raised positions relative to the dock platform. When
the dock leveler is not in use, the deck is substantially coplanar
with the adjacent, upper surface of the dock. To permit such
movement of the deck, a joint is typically formed along the
adjacent edges of the deck and loading dock surface. Dock levelers
typically have a portion of the pit and the associated portions of
the dock leveler which extend into the interior of the building.
Thus, even when the access door between the loading dock and the
building interior is closed, drafts may be created or conditioned
air may be lost through the joint unless some type of weather
sealing is utilized between the dock leveler and the wall surfaces
of the pit in which the leveler is mounted.
[0004] To help shield against weather while a vehicle is being
serviced at the dock, some type of seal is usually installed around
the perimeter of the doorway. Such seals are typically installed
along the upper and side edges of the doorway to help seal any air
gaps that may otherwise exist between the face of the building and
the rear of the vehicle. The dock leveler lip resting upon the rear
of the vehicle is often relied upon to seal most of the doorway's
lower edge.
[0005] The area or pit underneath a dock leveler's deck, however,
is usually exposed to outside air. This can create thermal problems
(i.e. wet decks, corrosion, heat loss, etc.), particularly when
there is a significant temperature differential between the indoor
and outdoor air. Warm outside air, for example, may condense
underneath a relatively cool deck of a dock leveler used in a cold
storage warehouse. The condensation can promote corrosion of
various parts of the dock leveler. Conversely, a heated building
during the winter may loose a significant amount of heat by thermal
conduction through the deck, as cold outside air cools the ramp
from underneath. Thus, regardless of whether the outside air is
colder or warmer than the inside air, it will generally be
beneficial to shield the underside of a dock leveler from outside
air.
[0006] One approach to this problem has been to provide a weather
shield or curtain over the front face of the pit to prevent the
flow of air between the pit cavity and the outside air. Examples of
various devices to solve the problem in this manner are shown in
U.S. Pat. Nos. 4,682,382; 6,502,268; 6,654,976; 7,146,673;
7,334,281. However, all of these approaches involve use of a
relatively complicated combination of moving parts that are subject
to wear and/or failure, and may be cause for shut down and/or
frequent replacement of components. More importantly, however, is
the recognition that, while such an approach reduces the heat
transfer by way of convection, it does little in the way of
reducing heat transfer by way of conduction and/or radiation. That
is, since the pit is a relatively large space (i.e. approximately
100 ft.sup.3), the use of such a curtain does not create an
effective so called "dead air space" which might otherwise provide
protection from heat transfer by way of radiation and conduction.
Therefore, even with such a curtain in place, the temperature in
the pit will be substantially the same as that of the ambient air,
and the temperature gradient between the air in the pit and the air
in the warehouse will result in a substantial transfer of heat
through the dock platform.
[0007] Another approach that has been taken to solve the problem is
that of insulating the underside of the dock platform by the
spraying of a coat of foam thereto. While such an approach is
effective and easy to implement at the time when the dock leveler
is manufactured in a plant, it is very difficult to implement by
retrofitting units that are already installed in the field. That
is, the application of a foam to the underside of an installed deck
would require a through cleaning of the deck underside in order to
remove the accumulated dirt and rust so that the foam would adhere
to the surface. Further, the accessible of the necessary equipment
for such application to the underside of the unit is severely
limited because of the small space of the pit.
DISCLOSURE OF THE INVENTION
[0008] In accordance with one aspect of the invention, a sheet of
insulative material is secured to the lower surface of the dock
leveler platform so as to thereby reduce the heat transfer through
the platform.
[0009] In accordance with another aspect of the invention, the
insulative material is applied to the bottom surface, by way of
sections whose width are selected to closely fit between adjacent
support beams, and to facilitate the proper width selection, the
insulative material is perforated in the longitudinal direction,
with the perforations being laterally spaced at close intervals, so
as to facilitate the easy tearing away of sections at proper
widths.
[0010] By yet another aspect of the invention, the perforated
material is attached to the lower deck surface by way of a
plurality of magnetic fasteners that are adhered to the lower
surface and hold a downwardly extending spike over which the
perforated material can be easily placed, with a self locking
washer then being installed on the extended end of the spike in
order to secure the material to the spike.
[0011] By yet another aspect of the invention, a thin sheet of
vinyl material is secured to one side of the insulative material so
as to hold the perforated sections together prior to and during the
installation process, and to act as a vapor barrier after the
insulative material has been installed in position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective bottom view of a dock leveler with
sheets of an insulative material attached thereto in accordance
with the present invention.
[0013] FIG. 1A is a fragmentary view of a portion thereof.
[0014] FIG. 2 is a side sectional view thereof.
[0015] FIG. 3 is a perspective view of the insulative material
thereof.
[0016] FIGS. 4A-4C are perspective views of the fastening apparatus
portion thereof.
[0017] FIG. 5 is a sectional view thereof as seen along lines 5-5
of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The invention is shown generally at 10 in FIG. 1 as applied
to a dock leveler 11. An extension plate or lip 18 is attached to
the front end 13 so as to be horizontally extendible to bridge the
gap between a truck and the dock leveler 11.
[0019] When not in use, the dock leveler is stored in a small place
referred to a pit 19 as shown in FIG. 2. A horizontally disposed
support frame 21 is disposed in the lower portion of the pit 19 and
is connected to the dock leveler 11 by way of a hydraulic cylinder
22 having pivot pins 23 and 24 at its ends. A pump (not shown) is
operably connected to the hydraulic cylinder 22 so as to
selectively cause it to move between the withdrawn position as
shown in FIG. 2 when the dock leveler is stowed, to the extended
position as shown in FIG. 1 wherein the dock leveler is raised to
an operable position.
[0020] Attached to the bottom surface 26 by way of welding or the
like, are a plurality of support beams 27 that extend
longitudinally along the length of the deck 12 with adjacent beams
being transversely spaced a distance D, a distance which will vary
substantially between various types and sizes of dock levelers and
may even vary within an individual dock leveler. For that reason,
the idea of installing, on a retrofit basis, insulation between
adjacent support beams is complicated, particularly when
considering the very little space that is available for an
installer within the pit 19.
[0021] Referring now to FIG. 3, there is shown a sheet 28 of
insulative material such as a closed cell foam. Such material is
commercially available from various sources. The sheet 28 includes
a plurality of lines 29 of discontinuous perforations 31 extending
longitudinally as shown in FIG. 3. That is, the perforations 31 are
cut entirely through the thickness of the sheet 28, with sections
32 therebetween not being perforated. This allows for an easy
tearing away of portions of the sheet 28 to selectively vary the
width of the resulting portion such that it fits tightly between
adjacent support beams 27.
[0022] In order to prevent the accidental tearing away, and to
present a stiffness for handling the sheets prior to and during the
installation process, a clear vinyl sheet 33 is applied to one side
34 of the sheet 28 as shown in FIG. 3. The vinyl sheet 33 may be
applied by way of a simple glue or the like. Such a sheet also
provide a vapor barrier on one side of the sheet 28 when in its
installed position.
[0023] Having selected the proper width and reduced the width of
the sheet 28 to the distance D between adjacent support beams 27,
the sheet 28 must be installed in place on the bottom surface 26 of
the deck 12. This is accomplished by way of the attachment
mechanisms 36 as shown in FIGS. 4A-4C. Included is a magnet 37
having an opening 38 therein to receive a spike therethrough after
which a self locking washer 41 is placed over the spike 39 as shown
in FIGS. 4A and 4B.
[0024] The magnet 37 may be of any suitable type, size and shape.
Such magnets are commercially available from several sources. The
self locking washer 41 should be formed of a robust material such
as galvanized steel and should be of a size which will securely
hold the sheet 28 in place without tearing through the material.
The perforated central portion 42 is formed in the manner of a self
locking washer which allows an easy insertion of the spike in one
direction but does not allow an easy removal thereof in the other
direction.
[0025] Considering now the steps of installing the sheet 28 in
position between adjacent support beams 27, the spike 39 is first
installed in the opening 38 of the magnet 37, and a plurality of
these assemblies are put in place between the adjacent support
beams 27, with the magnet 37 being magnetically attached to the
bottom surface 26 of the planar deck 12 as shown in FIG. 5.
Although they are shown in longitudinal alignment in FIG. 1, these
combinations can be randomly placed between adjacent support beams
27 so long as their longitudinal and/or lateral spacing is not too
great as to allow sagging of the sheets 28. After the magnets 37
and spikes 39 have been placed in position, the sheet 28, which has
been previously reduced to the desired width, is then placed in
position between the adjacent support beams 27 with the spikes
being allowed to penetrate through the sheet as shown in FIG. 5. A
self locking washer 41 is then placed in position over each of the
spikes 39 to complete the assembly process.
[0026] It should be recognized that the order as discussed
hereinabove can also be varied if desired. For example, it may be
desirable to first attach the spike 39 and magnet 37 combinations
in their installed positions with the spike 39 penetrating the
sheet, and then place the combination in place between adjacent
support beams 37. The self locking washer 41 can be installed
either before or after placing the sheet in position between
support beams 27.
[0027] While the present invention has been particularly shown and
described with reference to the preferred mode as illustrated in
the drawing, it will be understood by one skilled in the art that
various changes in detail may be effected therein without departing
from the spirit and scope of the invention as defined by the
claims.
* * * * *