AU619811B2

AU619811B2 - An inflatable bag

Info

Publication number: AU619811B2
Application number: AU31342/89A
Authority: AU
Inventors: Mark Gregory Trowland
Original assignee: BLUEFLAG Pty Ltd
Current assignee: XPT Power Industries Pty Ltd
Priority date: 1983-07-20
Filing date: 1989-03-15
Publication date: 1992-02-06
Anticipated expiration: 2004-07-18
Also published as: AU579830B2; NZ204978A; AU3078184A; AU3134289A

Description

B

S619811 COMMONWEALTH OF AUSTRALIA The Patents Act 1952-1969 MRK-G-EGQR-Y-TR(3LRAND- Name of Applicant(s): Address of Applicant(s): 4.-2--Red-f-en-St-reet, BiurandaQ,- uee-ns-and---44-2-r- M LC O v v© AL|(t.OIK^&- e^V+ ac.1 !<-2^arj eqc K I Actual Inventor(s): Address for Service: MARK GREGORY TROWLAND G.R. CULLEN COMPANY, Patent Trade Mark Attorneys, Dalgety House, 79 Eagle Street, Brisbane, Qld. 4000, Australia.

4 1t COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: 11 "AN INFLATABLE BAG" The following statement is a full description of the invention including the best method of performing it known to me.

T,

THIS INVENTION relates to an inflatable bag for lifting loads and in particular to an inflatable bag having connecting means which facilitates connection of the bag to a load such as a vehicle deck. As used herein, the term "deck" includes any load-bearing surface such as a trailer deck or truck deck.

U.S. Patent No. 3,659,899 to Phillps et al describes an inflatable bag for tipping a dump box of a utility truck. The bag is a bellows type bag and is secured JA f to the base of the dump box about the whole periphery of the 00 *0 S0 °dump box. The inflation of the bag is controlled and o 0 stabilised by side and rear braces. The whole arrangement is 00 0 of complex construction and does not provide a simple connection of the bag to the dump box such as would 105 facilitate conversion of an existing vehicle into a dump vehicle.

00 0 0 U.S. Patent No. 3,015,470 to Patchen describes a construction jack employing an inflatable bag. The load 0. engaging surface of the jack is provided by a rigi.d end plate and the bag is secured to the periphery of th end plate using a clamping ring. The Patchen jack can be used to raise a horizontally positioned load in the vertical direction or in another embodiment the jack can be used to tilt a load. The jack is apt to fail at the clamping ring during inflation of the bag.

It is an object of the present invention to provide f an inflatable bag which alleviates at least to some degree the problems associated with the prior art.

In one aspect the invention resides in an inflatable bag for lifting a load on inflation of the bag, the bag having opposed load engaging surfaces adapted to travel apart on inflation of the bag, each load engaging surface having a strip of flexible material secured thereto each strip having a free end to enable the bag to be secured to a load transmitting end plate.

Preferably, each strip includes two free ends and each strip is secured to the bag at a location between the free ends.

I i t Advantageously, each strip of material is secured across a major 0 0 08 portion of the width of the respective load engaging surface of the bags.

Preferably all the free ends of the strips extend in I o substantially the same direction across the respective load S engaging surfaces of the bag. Advantageously, each strip is secured in part by a gusset of flexible material extending from o 0 the respective strip to the respective load engaging surface of the bag.

o o0 Preferably the respective free ends of a respective 00 0 0 strip overlap.

Preferably, said bag has a rigid load-transmitting end plate secured to each load engaging surface thereof.

Preferably also, said apparatus further comprises pressure-relief means for preventing excessive gas pressure

!R~

_V_

within said bag, said pressure-relief means being arranged to operate at a predetermined gas pressure less than the gas pressure required to burst the bag.

In another aspect the invention resides in an inflatable bag kit for use in the conversion of a vehicle into a dump vehicle, the kit including the inflatable bag and two rigid load transmitting end plates, the end plates including spaced holes or slots, the bag being securable adjacent a side of an end plate by passing the free end of the strip through the hole or slot and securing the strip to the other side of the end plate.

By way of example only, a preferred embodiment of the present invention as applied to a tipping apparatus, in this case a trailer deck, is described in detail, with 1!3 reference to the accompanying drawings, in which: Figure 1 is a side view of a trailer incorporating a preferred bag according to the present invention; Figure 2 is a sectional side view of an assembled kit employing a preferred bag according to the invention; and Figure 3 is a side view of a tail pipe connector by which the bag can be inflated using a vehicle exhaust.

Referring to the drawings, a vehicle trailer 2 is J partly of conventional design, having a chassis 3 towbar 4, and pair of wheels 5 in known manner. However, the deck 6, instead of being rigidly secured to the chassis 3, is connected to the chassis only by hinges 7 adjacent the rear r i of the deck. The deck 6 may be flat or fitted with sides, in known manner.

Tipping apparatus 8 is secured between the chassis cross-member 9 and the underside of the deck 6, adjacent the front of the deck the end of the deck nearest of the towing vehicle).

The tipping apparatus 8 comprises a bag 10 made of tough, flexible, airtight material reinforced butyl rubber or vinyl) and provided with upper and lower end plates 0 ii I0:' 11, 12 made of a rigid material. The upper end plate 11 is S° secured to the underside of the deck, and the lower end plate 12 is secured to the cross member 9. Each load engaging o oo o surface or end of the bag 10 is secured to the corresponding end plate 11, 12 by a strip 13 of the same material as the bag 10. The strip 13 is secured across a major portion of the width, of the end of the bag, and is folded into a shape 0 o° of rectangular cross-section, with the ends 14 of the strip overlappad. The side 15 of each strip opposite said o overlapped ends 14 is welded to the adjacent end of the bag o. and bracing strips 16, 17, are welded at one end to the bag and at the other end to the side of the strip 13, at each oide of the bag. Each end plate 11, 12, is slotted, and the ends 14 of the strip 13 are passed one through each slot 18, 19, and then overlapped and secured to the end plate with a screw or rivet 20. When the bag 10 is inflated, it naturally attempts to assume a spherical shape, and if it is allowed to 6 do so, it will tear away from the end plates 11, 12. This tendency is overcome by the strips 13, 16, and 17 which are secured over a relatively large area of each end of the bag, and so hold the ends square when the bag is inflated, and distribute over said relatively large area the stress on the bag caused by restraining the bag when it is inflated.

At the lower end of the bag, a hose 25 extends through a hole in the end plate 12 and through the strip 13, a a 9and is sealed into the end of the bag.

1 9t Ot The hose 25 extends along the underside of the trailer towards the towing vehicle (not shown) and terminates d in a connector whereby the hose can be connected to the end S of a vehicle exhaust pipe. Said connector may be of any suitable type: e.g. a flexible pipe of slightly greater coco :diameter than the exhaust pipe, which is secured over the 0 00 exhaust pipe with a hose clip; or a cone of flexible material 0 which is push-fitted over the exhaust pipe, the smallest diameter of the cone being adjacent the hose; or a cone which a stepped or roughened exterior surface, the smallest ©o diameter of the cone being adjacent the exhaust pipe, and the 0 cone being push-fitted into the exhaust pipe.

A further possible design of connector is shown in Figure 3 a rigid connector pipe 26 of stepped external diameter is secured (removably or permanently) over or within the end of the exhaust pipe. The other end of the pipe 26 is fitted with a butterfly valve 27 which is rii

I,

U

r~t;P controlled by a remote control 28 to open or close said other end of the pipe. The end of the hose 25 is permanently or removably secured to a third pipe 29 connected to the connector pipe 26 upstream of the valve 27. With the butterfly valve 27 open, the vehicle exhaust is vented to atmosphere in the usual way; when the tipping apparatus is required, the butterfly valve is closed to direct the exhaust gases down the pipe 29.

The hose 25 includes a non-return valve 30 which prevents exhaust gases from flowing back from the bag to the exhaust pipe. Thus, when the bag is fully inflated, the 0:eo vehicle engine may be stopped without the bag collapsing.

*o 0

S

9 The hose 25 also is fitted with a T-connection 31, two limbs of which are each connected to the hose, and the third limb of which is sealed by a removable plug 32. The connection 00 o 31 is located downstream of the non-return valve 30, so that when the bag 10 is to be emptied, the plug 32 is removed, allowing the bag to empty rapidly.

To ensure that the bag 10 cannot accidentally be overinflated, a number of safety devices may be used, either alone or in combination. The first of these devices is the provision of a weak-walled section in the hose 25, so that this section will burst if the pressure in the hose becomes excessive. The second such device is a one-way valve (not shown) mounted in the top of the bag 10. This valve permits gas only to leave the bag, and is operated by a tie 36 u- secured between said valve and the lower end of the bag. The length of the tie 36 is such that when the bag 10 is nearly fully inflated, the tie becomes taut and pulls the valve open, to exhaust any further air entering the bag, and prevent the bag from being overinflated.

The third such device is a pressure-relief valve located in the hose 25. The valve 40 is a one-way valve spring-loaded so as to remain closed until a predetermined pressure is reached in the hose, and then open.

B: The front of the deck 6 is held down by hooks or clips (not shown) to prevent the deck bouncing when unloaded.

e*oo*Q The above described trailer is used as follows: the S trailer deck 6 is loaded in the usual way. To unload the trailer, the tailgate is removed or raised, the clips or hooks securing the front of the deck to the chassis are released, and the connector on the end of the hose 25 is connected to the vehicle exhaust pipe by any of the means described, above. The vehicle engine is left running, and the ft exhaust gases pass along the hose 25 into the bag 10 and O, inflate the bag. As the bag is inflated, it raises the front of the deck 6, thus tipping the deck. When the bag 10 is fully inflated the hose 25 is disconnected from the exhaust pipe, and the non-return valve 30 prevents air from escaping from the bag. To lower the deck again, the plug of the Tconnector 31 is removed so that air can leave the bag.

The bag 10 may be supported at its mid-point by a

I

9 hinged frame support 46 (see Figure The frame comprises two legs each hinged at one end to the chassis at or adjacent the hinges 7, the other end of each leg being secured to a hoop 46 around the mid-point of the bag. As the bag is inflated and rises, the legs pivot upwards, steadying the bag against sideways movement.

It is envisaged that the tipping apparatus of the present invention the bag 10 and hose 25 and fittings) may be built into a truck or trailer or may be sold id:" separately as a conversion kit for existing trucks or trailers.

0 o0 a a 0t

S

00 S f,

Claims

2. An inflatable bag as defined in claim 1 wherein each strip has two free ends, each said strip of material being Po secured across a major portion of the width of the respective load engaging surfaces of the bag. S3. An inflatable bag as defined in claim 2 wherein the free ends of the strips all extend in substantially the same direction across the respective load engaging surfaces of the bag.
9. 4. An inflatable bag as defined in any one of claims 2 or 3 wherein the free ends of a respective said strip overlap. 5. An inflatable bag as defined in any one of the preceding claims wherein each strip is secured in part by a gusset of flexible material extending from the respective strip to the respective load engaging surface of the bag. 6. An inflatable bag kit for use in the conversion of a vehicle into a dump vehicle, the kit including an inflatable bag according to any one of claims 1 to 5 and two rigid load transmitting end plates, the end plates including RA/ C. 1 T spaced holes or slots, the bag being securable adjacent a side of a said end plate by passing the free end or ends of a said strip through a said hole or slot and securing the strip to the other side of the end plate. 7. An inflatable bag substantially as described with reference to Figure 2 of the drawings. DATED this 15th day of March, 1989 -MARK--(^BGR--TRGW-LA-\&D- By their Patent Attorneys 1G.R. CULLEN CO. 0I t t t I