GB2218143A - Inflatable dock seals - Google Patents

Abstract

An inflatable dock seal provided around an access opening (14) in the wall of a building. comprising at least one inflatable element (20, 22, 23) which is secured to a supporting member (6). The inflatable element (20, 22, 23) has a sealing face which is displaceable, upon inflation of the inflatable element (20, 22, 23), away from the supporting member (6) for contact with a vehicle body to prevent, to a large extent, the flow of air between the interior of the building and the ambient surroundings. Retracting means are accommodated at least partially within the inflatable element for biassing the sealing face towards the supporting member (6) and comprises at least one elastic element or a system of pulleys and counterweights (46). A reversible pump may be provided to inflate and deflate the inflatable element (20, 22, 23). Excess air may be vented through leakage openings in the inflatable element (20, 22, 23). The reversible pump (24) may itself act as a retracting means. <IMAGE>

Description

INFLATABLE DOCK SEALS This invention relates to inflatable dock seals.

Such seals are provided around access openings in warehouses or other buildings, and are intended to be inflated for engagement with a truck or other transport vehicle backed up to the access opening for transfer of goods between the truck and the warehouse. The seals prevent, to a large extent, the flow of air between the interior of the warehouse and the ambient surroundings.

This reduces the energy requirements of the warehouse where, for example, its interior is maintained at a temperature significantly above or below that of the ambient surroundings. Inflatable dock seals are used, in particular, around access openings of refrigerated warehouses.

According to a first aspect of the present invention, there is provided an inflatable dock seal comprising an inflatable element which is secured to a supporting member, the inflatable element having a sealing face which is displaceable, upon inflation of the inflatable element, away from the supporting member for contact with a vehicle body, retracting means being accommodated at least partially within the inflatable element for biassing the sealing face towards the supporting member. Preferably, the retracting means comprises at least one elastic element which extends from a position adjacent the sealing face to a position adjacent the supporting member. The retracting means may, for example, comprise elastic cords.

The inflatable elements of inflatable dock seals commonly comprise elongate elements for engagement, respectively, with opposite sides of a vehicle and with the top of the vehicle. Preferably, at least one of these inflatable elements includes a rigid elongate member, extending lengthwise of the inflatable element, which is engaged by the retracting means, so that the inflatable element is retracted uniformly along-its length.

According to a second aspect of the present invention, there is provided an inflatable dock seal having an inflatable element provided with a sealing face for engagement with a vehicle, the sealing face being provided with a layer of wear-resistant reinforcing material.

The wear-resistent material may, for example, comprise an elastomeric material such as natural or synthetic rubber.

According to a third aspect of the present invention, there is provided an inflatable dock seal comprising at least one inflatable element which is inflatable by means of a pump, the pump being reversible in order to withdraw air from the inflatable element.

Preferably, the pump is provided with control circuitry which causes the pump to remain operative to supply air continuously to the inflatable element when the dock seal is in use. Excess air escapes through vents provided in the inflatable element. When the inflatable element is to be deflated, the pump is operated in reverse for a predetermined time, such as thirty seconds, to withdraw air from the inflatable element.

For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a perspective view of an inflatable dock seal; Figure 2 is a partially sectioned front view of the inflatable dock seal of Figure 1, with some parts omitted; Figure 3 is a diagrammatic sectional view of a top sealing element of the dock seal of Figure 1 ; - Figure 3A is a sectional view of a detail of the element of Figure 3 and Figure 4 is a diagrammatic sectional view of a side sealing element of the dock seal of Figure 1.

Figure 1 shows an inflatable dock seal structure 2 provided around an access opening 4 in the wall of a warehouse. The warehouse may, for example, be refrigerated for the storage of frozen goods. The structure 2 includes a canopy 6 which is secured to the wall of the refrigerated warehouse and is supported by support brackets 8 on a lower wall 10. The floor of the warehouse is at the level of the top of the wall 10, this level being comparable to that of the bed of a truck backed up to the access opening 4.

The canopy 6 is fabricated from side panels 12 and a top panel 14. The panels 12, 14 are made from a thermally insulating material. At the front edges of the side and top panels 12 and 14 respectively are provided curtains 16 and 18 of a flexible plastics material.

Side inflatable elements 20 and a top inflatable element 22 are secured to the canopy 6 behind the curtains 16, 18. Lower inflatable elements 23 are provided at the bottom ends of the side elements 20.

The lower inflatable elements 23 extend, when inflated, from the bottom of the side inflatable elemnets 20 to the lower wall 10. The inflatable elements 20, 22, 23 communicate with one another through appropriate openings (not shown), and the top inflatable element 22 is connected to an air pump 24.

A separate door (not shown) such as a roller shutter is provided for closing the access opening 4.

In use, a vehicle, such as a refrigerated articulated truck, is backed up to the access opening 4, the rear end of the trailer of the vehicle then extending into the canopy 6. The pump 24 is operated to inflate the inflatable elements 20, 22, 23 so that they extend inwardly of the access opening 4. The elements 20 and 22 engage the sides and top of the vehicle, while the elements 23 close the gap between the lower end of the side of the vehicle and the panel 12. This provides a substantially airtight seal between the interior of the warehouse and the vehicle, so that air cannot flow easily between the interior of the warehouse and the ambient surroundings. The door closing the opening 4 is opened to allow the transfer of goods between the truck (which may itself be refrigerated) and the warehouse.When the transfer is completed, the door at the access opening 4 is closed, the inflatable elements 20 and 22 are deflated and the vehicle is driven away.

The top sealing element 22 is shown in more detail in Figures 2 and 3. It comprises three compartments 26, 28 and 30 which communicate with one another through openings (not shown) provided between them.

The compartment 26 nearest the panel 14 is provided with beaded strips 32 which engage aluminium channels 34 secured to the panel 14, as shown in Figure 3A. The lowermost compartment 30 is provided, on the surface facing inwardly of the access opening 4, with a wearresistant reinforcing material 36 such as, for example, rubber sheet similar to that used for the skirts of hovercraft.

A partition 38 extends across the inner compartment 30 and supports brackets 40 which carry a length of plastics pipe 42. The pipe 42 extends the full length of the inflatable element 22 and projects from its ends. The projecting ends of the pipe 42 are provided with cords 44 which run over pulleys 46 and are secured, at the ends opposite the pipe 42, to counterweights 46. Plastics tubes 47 are secured to the side panels 12 for receiving the counterweights 46.

The side inflatable elements 20 are shown in more detail in Figure 4. As with the top inflatable element 22, the side elements 20 are secured to the side panels 12 by beaded strips 32 which engage aluminium channels 34. Also, the side inflatable elements 20 comprise three compartments 48, 49 and 50. The compartment 48 adjacent the panel 12 is provided with a reinforcing strip 52 which extends the full length of the inflatable element 20. Brackets 54 are secured, within the compartment 48, to the strip 52. A plastics pipe 56 is secured within the compartment 50, and elastic elements 58 extend between the brackets 54 and the pipe 56. The elastic elements 58 are thus accommodated entirely within the inflatable element 20. They may, for example, be made from aircraft quality shock cord, which comprises rubber strands enclosed in a woven polypropylene casing.

The sealing face of the innermost compartment 50 is provided with a wear-resistant, reinforcing material 60, similar to the material 36 of the inflatable element 22.

The lower sealing element 23 on each side also comprises three compartments 62, 64, 66 connected respectively to the compartments 48, 49, 50 of the side sealing element 20.

The pump 24 is reversible and is controllable from a manually operable control panel (not shown), by means of operating circuitry. When the control panel is operated to inflate the inflatable elements 20, 22 and 23 against a vehicle, the pump 24 operates continuously, excess air being vented through leakage openings (not shown) in the elements 20, 22, 23. When the inflatable elements 20, 22, 23 are to be retracted, the control panel is operated to terminate operation of the pump 24, but this initially causes the pump 24 to operate in reverse, so positively withdrawing air from the inflatable elements 20, 22, 23. Furthermore, the side elements 20 are retracted away from the vehicle body by means of the elastic elements 58 (carrying with them the lower elements 23), and the top inflatable element 22 is retracted away from the vehicle body by the counterweights 46 acting through the cords 44 on the pipe 42. Because the elastic elements 58 and the cords 44 act on the inflatable elements 20 and 22 through the pipes 42 and 56, the sealing faces, constituted by the reinforcing material 36 and 60 are withdrawn uniformly from the vehicle body.

The wear resistant material 36 and 60 provides protection against damage to the sealing faces of the inflatable elements 20, 22, 23 for example by abrasion should the vehicle be driven away from the access opening 4 before the inflatable elements 20, 22, 23 have been retracted fully.

Claims (15)

1. An inflatable dock seal comprising at least one inflatable element which is secured to a supporting member, the inflatable element having a sealing face which is displaceable, upon inflation of the inflatable element, away from the supporting member for contact with a vehicle body, retracting means being accommodated at least partially within the inflatable element for biassing the sealing face towards the supporting member.

2. An inflatable dock seal as claimed in claim 1 in which the retracting means comprises at least one elastic element which extends from a position adjacent the sealing face to a position adjacent the supporting member.

3. An inflatable dock seal as claimed in any preceding claim in which the retracting means comprises elastic cords.

4. An inflatable dock seal as claimed in claim 1, in which the retracting means comprises elongate flexible elements which are attached to the inflatable element and are acted upon by weights to retract the inflatable element.

5. An inflatable dock seal as claimed in any preceding claim, in which the inflatable element comprises an elongate element for engagement with the side of a vehicle or with the top of the vehicle.

6. An inflatable dock seal as claimed in any preceding claim in which the inflatable element includes a rigid elongate member, extending lengthwise of the inflatable element, which is engaged by the retracting means, so that the inflatable element is retracted uniformly along its length.

7. An inflatable dock seal as claimed in any preceding claim, in which the sealing face is provided with a layer of wear-resistant reinforcing material.

8. An inflatable dock seal as claimed in claim 7, in which the layer of wear-resistant reinforcing material comprises an elastomeric material such as natural or synthetic rubber.

9. An inflatable dock seal as claimed in any preceding claim, in which a pump is provided for inflating the inflatable element.

10. An inflatable dock seal as claimed in claim 9, in which the pump is reversible in order to withdraw air from the inflatable element.

11. An inflatable dock seal as claimed in claim 9 or 10, in which the pump is provided with control circuitry which causes the pump to remain operative to supply air continuously to the inflatable element when the dock seal is in use.

12. An inflatable dock seal as claimed in claims 9 to 11, in which vents are provided to enable excess air to escape from the inflatable element.

13. An inflatable dock seal having an inflatable element provided with a sealing face for engagement with a vehicle, the sealing face being provided with a layer of wear-resistant reinforcing material.

14. An inflatable dock seal comprising at least one inflatable element which is inflatable by means of a pump, the pump being reversible in order to withdraw air from the inflatable element.

15. An inflatable dock seal substantially as described herein, with reference to, and as shown in the accompanying drawings.