Inflatable seal

An inflatable seal for use in an adjustable dockboard unit for sealing the unit against the flow of air therethrough into and/or out of the building in which the dockboard is being used.

BACKGROUND OF THE INVENTION 
This invention relates to seals, and, more particularly, to inflatable 
seals which are particularly well adapted for use with adjustable 
dockboards, and the like. 
A primary object of the present invention is to afford a novel seal. 
Another object of the present invention is to afford a novel inflatable 
seal for use with adjustable dockboards. 
Adjustable dockboards, for use in the floors of loading docks, and the 
like, are well known in the art, being shown, for example, in U.S. Pat. 
No. 2,924,336, issued to G. P. Kelley on Mar. 14, 1961; U.S. Pat. No. 
3,117,332, issued to G. P. Kelley et al. on Jan. 14, 1964; and U.S. Pat. 
No. 3,137,017, issued to R. H. Pflager et al. on June 16, 1964. As is well 
known to those skilled in the art, one troublesome and common problem in 
the use of dockboards of the aforementioned type has been the relatively 
free circulation of air therethrough, into and out of the buildings in 
which such dockboards have been used, thus creating a heating and/or 
cooling problem. Various manners of trying to overcome this problem have 
been heretofore tried, such as, for example, using a drop-curtain on the 
dockboard, or permanently closing in the front of the depression over 
which the dockboard is located. The previous attempts to solve the 
aforementioned problem have had several inherent disadvantages, such as, 
for example, not being practical and efficient in operation; being 
complicated in construction and operation; requiring undesired 
modifications; or being expensive to install, and the like. It is an 
important object of the present invention to overcome such disadvantages. 
Another object of the present invention is to afford a novel seal for use 
with adjustable dockboards, which seal is operable to afford effective 
protection against the flow of air therethrough into and/or out of a 
building with which the dockboard is being used. 
Another object of the present invention is to afford a novel seal of the 
aforementioned type which is inflatable. 
An object which is ancillary to the foregoing is to afford a novel 
inflatable seal, which is so constituted and arranged that inflation 
thereof is effective to enhance the sealing characteristics of the seal. 
A further object of the present invention is to afford a novel seal of the 
aforementioned type which may be quickly and easily installed in operative 
position in an adjustable dockboard unit. 
Another object of the present invention is to afford a novel seal of the 
aforementioned type which is practical and efficient in operation, and 
which may be readily and economically produced commercially. 
Other and further objects of the present invention will be apparent from 
the following description and claims and are illustrated in the 
accompanying drawings which, by way of illustration, show a preferred 
embodiment of the present invention and the principles thereof and what I 
now consider to be the best mode in which I have contemplated applying 
these principles. Other embodiments of the invention embodying the same or 
equivalent principles may be used and structural changes may be made as 
desired by those skilled in the art without departing from the present 
invention and the purview of the appended claims.

DESCRIPTION OF THE EMBODIMENT SHOWN HEREIN 
An inflatable seal 1 is shown in the drawings in operative position 
relative to an adjustable dockboard unit 2, which is mounted in a loading 
dock 3, to illustrate the presently preferred embodiment of the present 
invention. 
The dockboard unit 2 may be of any suitable type readily available on the 
market, the particular unit 2, shown in the drawings, being of the type 
shown in the aforementioned Pfleger et al. U.S. Pat. No. 3,137,017, and 
embodying an elongated ramp 4, having a front end portion 5 and a rear end 
portion 6, with the rear end portion 6 hingedly connected to a supporting 
frame 7 disposed in a shallow pit or depression 8 in the loading dock 3, 
FIG. 2. In operation, the ramp 4 is movable around its hinged connection 9 
with the supporting frame 7 between a normal, lowered, at-rest position, 
wherein it is disposed in uniplanar relation to the floor 10 of the 
loading dock 3, as shown in FIG. 2, and a raised position, wherein it 
projects upwardly from its hinged connection 9 with the supporting frame 7 
at a forwardly opening acute angle to the plane of the floor 10, as shown 
in FIG. 3. Such raising and lowering of the ramp 4 may be accomplished by 
any suitable mechanism 11, such as, for example, by raising and lowering 
mechanism of the type shown in the aforementioned Pfleger et al. U.S. Pat. 
No. 3,137,017. 
Preferably, the dockboard unit 2 also embodies an extension lip 12 hingedly 
connected to the front end portion 5 of the ramp 4 for movement between a 
substantially vertically disposed, depending position, when the dockboard 
unit 2 is disposed in the aforementioned lowered position, as shown in 
FIG. 2, and a forwardly projecting raised position, as shown in FIG. 3, 
when the ramp 4 is disposed in raised position. Such raising and lowering 
of the extension lip 12 may be accomplished in any suitable manner, such 
as, for example, manually, or by mechanism of the type disclosed in the 
aforementioned Pfleger U.S. Pat. No. 3,137,017. 
In the preferred form of the invention shown in the drawings, the pit 8 is 
disposed in a concrete portion of the loading dock 3, and embodies an 
upright rear wall 13, with a flat, bottom wall 14 projecting horizontally 
forwardly from the bottom of the rear wall 13 to the open end 15 of the 
pit 8, and with two vertically upright sidewalls 16 and 17 projecting 
upwardly from opposite sides of the bottom wall 14 and extending forwardly 
from the rear wall 13 to the front end 15 of the pit 8, FIGS. 2 and 4. 
In the dockboard unit 2, shown in the drawings, the supporting frame 7 
includes two elongated reinforcing beams 18 and 19, FIG. 4, projecting 
from the rear portion of the pit 8 to the front portion thereof in 
substantially parallel relation to each other and terminating in 
rearwardly spaced relation to the front end 15 of the pit 8; and the ramp 
4 embodies a plurality of elongated reinforcing beams 20, disposed in 
spaced parallel relation to each other and projecting from the rear 
portion of the pit 8 to the front portion thereof in underlying, 
reinforcing relation to the deck 21 of the ramp 4, FIGS. 2 and 4. 
The inflatable seal 1 embodies a substantially rectangular-shaped, body 
portion in the form of an air bag 22, having a front wall 23, a rear wall 
24, two oppositely disposed sidewalls 25 and 26 extending between the 
front wall 23 and the rear wall 24, a top wall 27 closing the top thereof, 
and a bottom wall 28 closing the bottom thereof, FIGS. 3 and 4. A pair of 
spaced flaps 29 project outwardly from the top wall 27 and extend 
substantially the full length thereof in parallel relation to each other, 
and, similarly, a pair of spaced flaps 30 project outwardly from the 
bottom wall 28 and extend substantially the entire length thereof in 
parallel relation to each other, for a purpose which will be discussed in 
greater detail presently. 
An elongated, substantially straight beam 31, FIGS. 3 and 4, is mounted on 
the lower face of the beams 20 and secured thereto by suitable means, such 
as bolts, or the like, not shown, the beam 31 extending substantially the 
full width of the ramp 4. Similarly, an elongated, substantially straight 
beam 32 is mounted on the bottom wall 14 of the pit 8, forwardly of the 
supporting beams 18 and 19, FIGS. 3 and 4, and secured thereto by suitable 
means, such as bolts, or the like, not shown, the beam 32 extending 
substantially the full width of the pit 8. The beams 31 and 32 may be made 
of any suitable material, such as, for example, wood. 
In securing the inflatable seal 1 in operative position in the loading dock 
3, the flaps 29 may be disposed on opposite sides of the beam 31, FIG. 3, 
and secured thereto by any suitable means such as, for example, nails 33, 
FIG. 4; and the flaps 30 may be disposed on opposite sides of the beam 32, 
FIG. 3, and secured thereto by any suitable means such as nails 34, FIG. 
4. 
The body portion 22 of the inflatable seal 1, and the flaps 29 and 30 
preferably are made of a suitable, substantially air-impervious material, 
such as, for example, rubber impregnated nylon fabric, or the like. Also, 
preferably, a plurality of elongated, spaced, restraining members or 
straps 35 extend between, and are secured to the front wall 23 and the 
rear wall 24 of the body portion 2, in spaced relation to each other, FIG. 
3, in position to periodically restrain the walls 23 and 24 from 
excessively bulging outwardly away from each other when the inflatable 
seal 1 is inflated. 
For inflating and deflating the inflatable seal 1, a suitable electrically 
operated motor-blower unit 36, preferably is mounted in the lower portion 
of the pit 8 in closely adjacent relation to the inflatable seal 1, the 
motor-blower unit 36 being operatively connected to the lower end portion 
of the body portion 22 of the inflatable seal 1 by a suitable coupling, 
such as a flexible hose 37, FIGS. 3 and 4. Suitable controls, not shown, 
for the motor-blower unit 36 may be disposed at any suitable, readily 
available location, such as, for example, at the front of the loading dock 
3. The motor-blower unit 36 may be of any suitable type readily available 
on the market, which is effective, when in operation, to force air into 
the seal 1, and, when not in operation, to exhaust air from the seal 1 by 
permitting the air to escape through the motor-blower unit 36. 
In the preferred form of the invention shown in the drawings, the spaces 
between the top of the beam 31 and the bottom of the deck 21 of the ramp 
4, not filled by the beams 20, are filled with a suitable, substantially 
air impervious sealing or insulating material 38, FIG. 4, such as a foamed 
polyether or polyester. Preferably, the material 38 is adhesively secured 
to the lower face of the deck 21 of the ramp 4. 
The body portion 22 of the inflatable seal 1 is of such width, between the 
sidewalls 25 and 26 thereof, that, when the seal 1 is in inflated 
condition, the sidewalls 25 and 26 are yieldingly, pneumatically held in 
sealing engagement with the sidewalls 16 and 17 of the pit 8, as shown in 
FIG. 4. It will be remembered that the beam 31 is secured to the lower 
faces of the beams 20 of the ramp 4, in immediately underlying relation to 
the insulating material 38, and that the beam 32 is disposed on the bottom 
14 of the pit 8. With this construction, and with the flaps 29 and 30 of 
the inflatable seal 1 secured to the beams 31 and 32, respectively, the 
flow of air between the top of the body portion 22 and the ramp 4, and 
between the bottom of the body portion 22 and the bottom 14 of the pit 8 
is effectively restrained. If desired, the top wall 27 and the bottom wall 
28 of the body portion 22 may embody sufficient material that, when the 
seal 1 is in inflated condition, they are bulged outwardly into engagement 
with the lower faces of the beams 20 and insulating material 38 and the 
upper face of the bottom wall 14 of the pit 8, respectively, as shown in 
broken lines in FIG. 3. 
In the operation of the inflatable seal 1, when the motor-blower unit 36 is 
turned off, the body portion 22 is vented to atmosphere and, therefore, is 
in deflated condition. Normally, the inflatable seal 1 is in such 
condition when the dockboard unit 2 is in lowered position, as shown in 
FIG. 2. Even in this condition, it affords an effective seal for 
restraining the flow of air into or out of the pit 8 through the open 
front end thereof. 
When the dockboard unit 2 is moved into raised position, as shown in FIG. 
3, the inflatable seal 1 is pulled upwardly thereby into extended 
position. Even in collapsed condition, the inflatable seal 1 affords an 
effective retarding barrier to the flow of air into or out of the pit 8 
through the front end portion thereof. However, normally, when the 
dockboard unit 2 is disposed in raised position, or during the raising 
thereof, the motor-blower unit 36 is energized to thereby feed air into 
the body portion 22 of the inflatable seal 1 and thus dispose it in 
expanded condition, as shown in FIGS. 3 and 4. Under such conditions, the 
inflatable seal 1 affords a substantially impervious seal against the 
passage of air into or out of the pit 8 through the front end portion 
thereof, the sidewalls 25 and 26 of the seal 1 being yieldingly pressed 
against the sidewalls 16 and 17 of the pit 8, the bottom of the body 
portion 22 being effectively sealed to the bottom wall 14 of the pit 8, 
and the top of the body portion 22 being effectively sealed to the bottom 
surface of the ramp 4 of the dockboard unit 2. When it is desired to again 
lower the dockboard unit 2, the motor-blower unit 36 may be turned off to 
vent the inflatable seal 1 to atmosphere and thereby permit collapse of 
the same, and the dockboard unit 2 may be lowered into normal, at-rest 
position, as shown in FIG. 2. 
A modified form of the present invention is illustrated in FIGS. 5-8, 
inclusive, of the drawings. This modified form of the present invention 
embodies the same general principles as the preferred form illustrated in 
FIGS. 1-4, inclusive, and parts which are the same as parts shown in FIGS. 
1-4 are indicated by the same reference numerals, and parts which are 
similar but which have been substituted for parts shown in FIGS. 1-4 are 
indicated by the same reference numerals with the suffix "a" added. 
The inflatable seal 1a, shown in FIGS. 5-8, is the same in construction as 
the inflatable seal 1, shown in FIGS. 1-4, except that the elongated, 
restraining members or straps 35a extend upwardly, at a rearwardly opening 
acute angle to the horizontal, from the front wall 23 to the rear wall 24 
of the inflatable seal 1a; and two pairs of other elongated, restraining 
members or straps 39 and 40 are secured to, and extend between the front 
wall 23 and the rear wall 24 of the inflatable seal 1a, on opposite 
horizontal sides of the two outermost straps 35a disposed in the vertical 
mid-portion of the inflatable seal 1a, FIGS. 5 and 7. Like the restraining 
members 35a, the restraining members 39 and 40 are secured to the front 
wall 23 and the rear wall 24 by suitable means, such as, for example, 
stitching, and project upwardly from the front wall 23 to the rear wall 24 
at the same acute angle to the horizontal, as the restraining members 35a. 
Also, the restraining members 39 and 40 project outwardly, at a rearwardly 
opening acute angle, from the restraining members 35a, with respect to 
which they are adjacently disposed. 
The acute angle at which the restraining members 35a, 39 and 40 are 
disposed to the horizontal may be any suitable angle, but, preferably, is 
not substantially less than 15 degrees and not substantially more than 25 
degrees, and, preferably, is in the nature of 20 degrees. Also, the angle 
at which the members 39 and 40 project outwardly from the respective 
adjacent members 35a may be any suitable angle, but, preferably, is not 
substantially less than 20 degrees and not substantially more than 40 
degrees, and, preferably, is in the nature of 30 degrees. Thus, in the 
preferred form of the inflatable seal 1a, if the straps 35a are 7 inches 
in length, the straps 39 and 40 may be in the nature of 13 inches in 
length, and the rear end portions of the straps 35a, 39 and 40 may be 
disposed two and one-half inches above the front end portion thereof. 
With this construction, when the dock leveler, such as the dock leveler 2, 
in which the inflatable seal 1a is disposed, is moved from the raised 
position shown in FIG. 3 to the lowered position shown in FIG. 2, with the 
seal 1a in inflatable condition, the latter is caused to collapse 
downwardly and rearwardly from the position shown in FIG. 5 to the 
position shown in FIG. 6, the straps 35a, 39 and 40 applying internal 
tension on the walls 23 and 24 effective to cause such collapsing movement 
of the inflatable seal 1a. This, it will be seen, is effective to insure 
that the seal 1a does not bulge outwardly or forwardly from the dock 
leveler 2 under such conditions. 
Of course, the inflatable seal 1a may be in deflated condition during 
raising and lowering of the dock leveler 2, in which it is mounted, and, 
under those circumstances, it will extend or collapse substantially 
vertically in the same manner as heretofore described with respect to the 
inflatable seal 1, shown in FIGS. 1-4. 
From the foregoing it will be seen that the present invention affords a 
novel inflatable seal. 
In addition, it will be seen that the present invention affords a novel, 
effective seal for use with adjustable dockboard units. 
Also, it will be seen that the present invention affords a novel seal of 
the aforementioned type which is practical and efficient in operation, and 
which may be readily and economically produced commercially. 
Thus, while I have illustrated and described the preferred embodiment of my 
invention, it is to be understood that this is capable of variation and 
modification, and I therefore, do not wish to be limited to the precise 
details set forth, but desire to avail myself of such changes and 
alterations as fall within the purview of the following claims.