GB2273960A

GB2273960A - Inflatable tube for sealing or actuating

Info

Publication number: GB2273960A
Application number: GB9400031A
Authority: GB
Inventors: Robert Jackson
Original assignee: TARGET ENGINEERING
Current assignee: TARGET ENGINEERING
Priority date: 1993-01-04
Filing date: 1994-01-04
Publication date: 1994-07-06
Also published as: GB9400031D0

Abstract

A device comprising a closed elongate flexible tube is constituted by two parallel sections, one of which is retained in a rigid channel member 6, and the other which can be inflated either to form a seal eg against a door D or to operate as an actuating device eg to lift a plate 46. Numerous applications are disclosed, eg moving the neck of a back to a heat sealing device, locating a bottle, forwarding a strip material, operating a hinge, moving a door seal, forming part of conveyor means, a shutter in a ventilation arrangement or a dam in waterworks. <IMAGE>

Description

AN INFLATABLE SEALER/ACTUATOR This invention relates to inflatable actuators and is particularly concerned with devices which are intended to seal or actuate mechanisms by inflating sealed tubular members.

British patents 646862, 1447628, 1450106, 1476496 and 2228058 disclose inflatable sealed tubular members which inflate to form a seal between two or more components.

US patents 3796010, 4322923, 4399317 and 4870783 disclose similar inflatable sealing arrangements.

Due to the construction of the devices listed above, the distance between the parts to be sealed against each other is severely limited, ie it is not possible to cause an effective seal between two members which are, in their unsealed condition, a considerable distance apart.

It is an object of this invention to provide an inflatable device which overcomes the shortcomings of the above known arrangements; and/or provide improvements generally.

A further need has been identified for a device based on a inflatable tube arrangement for sealing the gap between a door and its surround, whereby the sealing member may be moved away from the door during its inoperative mode in order to allow the door to open without contacting the sealing member during such movement.

With the on-going demands for air-conditioning in buses and railway coaches in hot climates, and for internal heating in cold climates, there arises a demand for efficient sealing of the doors of the vehicle.

It is a further object of this invention to provide a device for sealing of a vehicle which attempts to fulfil the above desiderata.

According to the present invention there is provided an inflatable sealing or actuating device as claimed in the accompanying claims.

In an embodiment of the invention there is provided a device for sealing or actuating members comprising a closed flexible tubular member, means for inflating the tubular member, one part of which is constrained within a first member and a second part of which is adapted to move with respect to the first part when the tubular member is inflated and which reverts to its original non-inflated condition when it is deflated.

Preferably the tubular member is so constructed that in the deflated condition the first part and the second part are substantially in parallelity one with the other.

In a further embodiment of the invention there is provided a device for sealing a gap between a door and its surround comprising a closed flexible tubular member, one part of which is constrained within a first member and a second part of which is adapted to move with respect to the first part when the tubular member is inflated and which reverts to its original non-inflated condition when it is deflated, and wherein the second part has attached thereto, or formed integrally therewith, a flexible elongate flap member adapted to sealingly engage the door when in its operative position, and to move out of the path taken by the opening door when it is in its inoperative position.

Preferably the second part of the closed tubular member has affixed thereto an elongate member provided with a channel into which a flexible elongate flap member may be removably secured.

According to the invention there is also provided a device for sealing a gap comprising an inflatable tubular member with an associated flap member, and a corresponding method.

The above and other features will be understood from the following description which is given by way of example only with reference to the accompanying drawings in which: Fig 1 is a perspective view of a sealing device according to the invention; Fig 2 is an enlarged view of part of the sealing device; Fig 3 is a section view of the device seen in Fig 1 but in its operative position; Figs 4 and 5 are section views of a device in inoperative and operative position respectively in use as a door seal; Fig 6 is a perspective view of the further use as a door seal; Fig 7 is a perspective view of a further embodiment; Fig 8 is a perspective view of a number of devices used as a ventilating or water flow control system; Fig 9 is a perspective view of a rectangular sealing device; Figs 10 to 19 are section views of further applications of the device.

Figs 20 to 23 are section views of the sealing device adapted for sealing the gap between a hingeable or slidable door and its surround.

As seen in Figs 1 to 3, a sealing device 1 according to the invention comprises a longitudinal strip 2 of profile section having a base portion 3, an upstanding rib 4 and an in-turned section 6 to form a casing 7. The strip is preferably extruded from metal or could be of a rigid plastics material.

A hollow sealing strip 8, extruded from a natural or synthetic rubber is illustrated clearly in Fig 2 and is formed with a lower portion 10 having horizontal walls 12, 14 and an upper portion 16 having horizontal walls 18, 20 forming a cavity 21 therebetween. The endmost portions 9 of the sealing strip are closed by welding or by vulcanizing to form a single closed tube. The lower portion is located within the casing 7 and a valve 22 passes through the lower wall 12 of the strip 8 and the base portion 3 of the casing.

The valve is connected to a supply of pressurized air via a control valve (not shown).

The arrangement is such that when air under pressure is passed into the cavity 21, the upper portion 16 tends towards a vertical configuration with respect to the lower portion 10 as illustrated in Fig 3.

When the air pressure is exhausted through the valve 22, the sealing strip 8 reverts to its original inoperative position due to the "memory" within the material.

Exhaustion of the air within the cavity 21 may be due to the reversion of the strip 8 to its original position, or alternatively the air may be rapidly exhausted by connection to a vacuum source via a valve system.

Various applications of use of a sealing device according to the invention will now be described.

Figs 4 and 5 illustrate the use of such a seal to seal a gap below a door D. In that arrangement the profile strip 2A retains a sealing strip 8 within a casing 7 and the upper portion of the strip lies in its collapsed inoperative position whereby the door may pass over it to be opened.

The strip 8 is actuated by passing air under pressure into the cavity 21 via the valve 22 whereupon the upper portion is elevated into sealing relationship as seen clearly in Fig 5.

A somewhat similar arrangement is illustrated in Fig 6 where the sealing strip is effective on the top surface of the door D.

Fig 7 shows an arrangement for sealing the area surrounding an elevatable platform, eg in a public transport vehicle. The platform P is moved between a raised position as shown to a lowered position to allow more convenient alighting and embarking for passengers and the sealing device of the invention is actuated by pneumatically inflating the strip after the platform has been raised, this effectively prevents ingress of water and soil to the interior of the vehicle. Air is expelled from the cavity to allow the strip to assume its inoperative position before the platform is lowered.

Fig 8 shows an arrangement of pneumatic louvres where an array of profile strips 2B house a number of sealing strips 8. In their collapsed inoperative positions the louvres are open and in the inflated position shown, the louvres are closed to prevent passage of air or water therebetween. Such an arrangement is intended for use either in a ventilation system or a dam arrangement in a waterworks system; Fig 9 illustrates an arrangement for all-round sealing of a rectangular opening. The sealing strips and their housings are arranged in the form of a closed rectangular frame in order to seal a vertical or horizontal trap door.

Figure 10 shows an arrangement for use in a heat sealing mechanism for a plastics bag packaging device.

Filled plastics bags 26 are passed on a conveyor 28 past a heated element 30. At an appropriate time a seal strip 8 is inflated as already described to urge the neck of the bag against the heated element in order to close seal the bag.

In the arrangement seen in Figure 11 the sealing devices 1 are located on either side of the path of a bottle B as it passes in a step by step manner along a conveyor 32. In a similar arrangement, not shown, the bottle may be raised into position by an elevator and the sealing device 1 may be of annular form in order to grip and axially locate the bottle for filling, capping and/or labelling.

Figure 12 shows an arrangement for progressively feeding strip material S in a step by step motion. A roll of strip material is freely rotatable about its axis. A feed mechanism comprises a piston cylinder mechanism 34 whose piston rod 36 is connected to a support plate 38 on which is mounted a sealing device 1.

In operation the strip S overlies a platen 40 and the piston cylinder device is extended as illustrated, but with the sealing strip 8 deflated. The valve is next actuated to inflate the strip 8 so that its portion 16 engages the surface of the strip material S. Withdrawal of the piston rod 36 into its cylinder 34 pulls the strip along the platen by a predetermined amount after which the strip 8 is deflated in readiness for the forward, return stroke of the device.

Figures 13 and 14 illustrate the use of the device as a means for raising or lowering a support plate in a conveying arrangement. A sealing device 1 is mounted on a stationary base plate 42 housed within a rectangular hollow section beam 44 to which is secured a support plate 46. A spring 48 urges the beam 44 and support plate 46 in a downward direction and the sealing device 1 in its deflated, inoperative condition, is located between the base plate 42 and the inner top-side of the beam.

When it is required to elevate the beam and support plate, air under pressure is caused to enter the cavity 21 to inflate the strip 8. This unfolds the sealing strip 8 and as a result of the pressure on the underside of the top of the beam raises the beam and support plate against the action of the spring 48.

Opening of the valve 42 causes deflation of the strip 8 with consequent lowering of the beam and support plate.

In Figures 15 and 16 are illustrated the arrangement of the inflatable sealer strip when used to actuate a hinge mechanism.

The lower part of the hinge 50 illustrated includes the casing 7 and the movable part 52 of the hinge rests on or is secured to the upper part 16 of the sealing strip 8. As seen clearly in Figures 15 and 16, inflation of the strip 8 causes the hinge to pivot about its hinge 54. Deflation of the strip enables, or causes, the hinge to re-close In an alternative arrangement seen in Figures 1719, the devices according to the invention are utilized in a "walking beam" type of conveyor system.

As seen in the drawings a number of devices 1 are located parallel to and between stationary beams 54 and, besides being inflatable as already described, are reciprocable longitudinally between the beams.

The devices 1 lie in the plane below the level of the stationary beams.

In operation articles A to be conveyed are placed on the conveying system as seen in Figure 17, and rest on the beams 54. The sealing strips 8 are then inflated to raise the articles off the beams 54 after which the devices 1 are moved in the direction of the arrows B in Figure 19 to propel the articles along the system. The strips 8 are then deflated to lower the articles on to the beams 54 once more and the devices 1 are returned to their initial position ready to repeat the cycle again.

In a still further alternative arrangement (not shown) a bank of devices 1 may themselves act as conveying means for lightweight and delicate articles.

An array of the devices forming the bank, have their sealer strips inflated in sequence to form a wave-like motion to convey the articles there-along normal to the longitudinal direction of the devices.

Referring now to Figures 20, 21 and 22 of the drawings there is provided a sealing mechanism 102 for sealing a gap G between the top of a door D and an upper part of a doorway. The mechanism comprises an extruded metal housing 104 having an upper horizontal wall 106, a downwardly depending wall 108 and two ribs 110 depending inwardly from the wall 108 and defining a horizontal channel 112. At the foremost end of the upper horizontal wall 106 is a downwardly depending lip 114.

A closed flexible tubular member 116 has one part 118 which is constrained within the channel 112, and a second part 119 which is adapted to move with respect to the first part when the tubular member is inflated.

As seen in Figures 20 and 21, attached to one face of the second part 119 of the tubular member is a metal strip 120 which is formed at one end as a channel section 122. A longitudinally extending sealing blade 124, having a curved aerofoil crosssection is retained at its thicker end within the channel 122. The metal strip 120 may be attached to the closed tubular member by adhesive or by vulcanisation. Similarly the blade 124 may be retained within the fork 122 by adhesive or vulcanization. Preferably a heat-activatable adhesive is used in order to facilitate ready removability and replacement of the blade if it becomes damaged or worn.

As seen clearly in Figure 20, when the device is in its in-operative, non-inflated position the door D may be opened without striking the sealer blade 124.

When the door is closed in order to seal the gap G the flexible closed tubular member is inflated by the ingress of compressed air which causes the second part 119 of the tubular member to move to the position seen clearly in Figure 21 wherein the metal strip 120 adopts an approximately vertical position and the sealing blade 124 contacts the upper margin of the door firmly but resiliently. The strip 120 abuts against the lip 114 and the resilience of the thinner edge margin of the blade 124 engages with any imperfections in alignment or flatness of the door.

Thus an effective seal is maintained when required, yet allowing opening and closing of the door without wearing the sealing mechanism due to its retracted position of Figure 20. The inside face of the lip 114 may be provided with a strip of resilient material, eg rubber, to reduce the sound as the metal strip 120 contacts the downwardly depending lip.

The mechanism is simple and has no mechanically moved parts requiring accommodation, maintenance and power drive, and since it is common practice to actuate coach door opening and closing mechanisms pneumatically, a supply of compressed air for inflating the tubular member is already available for use with the sealing mechanism.

In the mechanism illustrated in Figure 22 the blade 124 is either extruded in one with the tubular member 116 or may be extruded separately and vulcanized on to the member 116. Otherwise the mechanism works as already described with reference to Figures 20 and 21.

An alternative arrangement is illustrated in Figure 23 wherein the closed tubular member 116A comprises three sections. A first section 118A is retained within a channel section 112A formed in a longitudinal strip 113 secured to a portion of a coach body above its doorway. The second section 119A of the member 116A is turned through approximately 180o from the first section 118A. A third section 121A is turned through approximately 180" two the second section and lies approximately parallel to that in its in operative position.

When the closed tubular member is inflated the second part of the member adopts a position away from the first part and the third part is pressed into contact with the outer face of the door as in the configuration seen in chain lines in Figure 23.

Thus in all the embodiments seen in Figures 2023, an effective seal is provided in operation and the door is openable without contacting the sealing element when the seal is in its in-operative position.

Claims

CLAIMS :

1 An inflatable sealing or actuating device comprising a closed flexible tubular member, means for inflating the tubular member, one part of which is constrained within a first member and a second part of which is adapted to move with respect to the first part when the tubular member is inflated and which reverts to its original non-inflated condition when it is deflated.

2 A device according to claim 1 wherein the tubular member is so constructed that in the deflated condition the first part and the second part are substantially in parallelity one with the other.

3 A device according to claim 2 wherein the first part and the second part of the tubular member lie substantially orthogonally to each other in their inflated state.

4 A device according to claim 1 wherein the first member comprises a rigid elongate member having a channel section adapted to retain and constrain said one part of the closed flexible tubular member.

5 A device according to claim 4 wherein the rigid elongate member is formed of metal by an extrusion process.

6 A device according to claim 4 wherein the rigid elongate member is formed of a plastics material by an extrusion process.

7 A device according to claim 1 wherein the closed flexible tubular member is formed by extruding natural or synthetic rubber to form a cross-section having two parallel cavities and having a memory which induces it to revert automatically to its original form after any deformation has taken place.

8 A device according to claim 7 wherein the extruded tubular member is closed at its ends by welding or by vulcanizing to form a single closed tube.

9 A device according to claim 1 wherein the means for inflating or deflating the tubular member includes a first valve member fitted into the tubular member and connected to a source of compressed fluid.

10 A device according to claim, 9 wherein the fluid is air.

11 A device according to claim 9 wherein control means are provided to actuate a further valve member to allow air from its source to flow under pressure from the source to the first valve member.

12 A device according to claim 11 wherein the further valve member connects the first valve member to an exhaust system.

13 A device according to claim 11 wherein the further valve member connects the first valve member to an alternative vacuum source.

14 A device as claimed in any of the above claims wherein the first member is secured adjacent parts to be sealed such that the second part of the tubular member is out of contact with a part to be sealed when it is non-inflated and in close sealing contact therewith when it is inflated.

15 A device according to claim 14 wherein the parts to be sealed comprise a door and a door frame.

16 A device according to claim 14 wherein the parts to be sealed comprise a movable platform and its surround.

17 A device according to claim 14 wherein the parts to be sealed constitute louvres of a ventilating system.

18 A device according to claim 14 wherein the parts to be sealed constitute louvres of a dam arrangement in a waterworks system.

19 A device according to claim 14 wherein the first member and the flexible tubular member constitute a rectangle.

20 A device according to claim 1 wherein the second part is provided with an elongate extension adapted to close firmly in contact with a closed door when the second part is inflated and to move out of the path of the door when in its non-inflated condition.

21 A device according to claim 20 wherein the elongate extension is removably retained within a channel member attached to the second part.

22 A device according to claim 20 wherein the elongate extension is welded or vulcanized to the second part.

23 A device according to claims 1 or 2 wherein the second part is formed with a third part constituting a sealing member adapted to be inflated along with the second part and to sealingly engage a member to be sealed.

24 A device according to claim 23 wherein the first, second and third part are substantially in parallelity when in the deflated condition.

25 A device according to claim 1 wherein the device is an actuating member and the second part is inflated to urge a plastics package item against a heat sealing device.

26 A device according to claim 1 wherein the device is an actuating device arranged on either side of a conveyor system, and inflation of the second part acts to grip and locate an item on the conveyor system for further processing.

27 A device according to claim 26 wherein the item is a bottle and the further processing includes filling, capping, or labelling.

28 A device according to claim 1 wherein the device is an actuating device used for feeding strip material in a step-by-step manner by inflating the second part in order to grip the material during the feeding operation.

29 A device according to claim 1 wherein the device is an actuating device and where the device supports and actuates a supporting beam of a conveyor system by elevating the beam when the second part is inflated and lowering the beam when the second member is deflated.

30 A device according to claim 1 wherein the device is an actuating device and wherein the first member is formed with a hinged plate and the second part is adapted to rock the hinged plate about a hinge pin when the second part is inflated and to lower the hinged plate when it is deflated.

31 A device according to claim 1 wherein the device is an actuating device and wherein the second part is adapted to raise and lower items of a conveyor system by supporting the items directly on the second part when it is inflated and by lowering the items onto a stationary beam when deflated.

32 A sealing device substantially as hereinbefore described with reference to Figures 1 to 8.

33 A sealing device substantially as hereinbefore described with reference to Figure 9.

34 A sealing device substantially as hereinbefore described with reference to Figures 20 to 22.

35 A sealing device substantially as hereinbefore described with reference to Figure 23.

36 An actuating device substantially as hereinbefore described with reference to Figure 10.

37 An actuating device substantially as hereinbefore described with reference to Figure 11.

38 An actuating device substantially as hereinbefore described with reference to Figure 12.

39 An actuating device substantially as hereinbefore described with reference to Figures 13 and 14.

40 An actuating device substantially as hereinbefore described with reference to Figures 15 and 16.

41 An actuating device substantially as hereinbefore described with reference to Figures 17 and 18.

42 A method of actuating comprising providing a closed flexible tubular member and inflating said tubular member while one part thereof is constrained within a first member, and causing a second part thereof to effect an actuating movement when inflated, and subsequently to revert to its non-inflated condition.

43 A method of actuating substantially as described herein with reference to the accompanying drawings.