WO2003095932A1

WO2003095932A1 - Lightweight gas generator device

Info

Publication number: WO2003095932A1
Application number: PCT/ZA2003/000063
Authority: WO
Inventors: Jurie Wynand Van Dyk; Jacob Paul Roux Van Dyk; Johannes Theodorus Schonken; Johan Francois Lombard
Original assignee: Jurie Wynand Van Dyk; Jacob Paul Roux Van Dyk; Johannes Theodorus Schonken; Johan Francois Lombard
Priority date: 2002-05-13
Filing date: 2003-05-13
Publication date: 2003-11-20
Also published as: AU2003230425A1

Abstract

A gas generator device (10) comprises a cartridge (12) containing a pyrotechnic charge (14) and igniting means for remotely igniting the charge. The cartridge (12) is formed at opposite ends with combustion gas settling chambers (18). The chambers (18) are in gasflow communication with a combustion chamber (20) via gas outlet nozzles extending along ports (24). Escaping of gas generated by the combustion reaction for inflating inflatable equipment takes place via a plurality of discharge outlets in the form of passages (32) formed through end flanges (34) forming part of the casing (22) of the cartridge (10). The passages (32) are arranged in facing pairs facing one another alongside the side of the tube (16). This limits the generation of resultant thrust on the device (10) once in use. The igniting means includes two igniter switches (36) arranged to electrically ignite the charge (14).

Description

(1) TITLE OF THE INVENTION LIGHTWEIGHT GAS GENERATOR DEVICE

(2) BACKGROUND TO THE INVENTION

Situations are often encountered where the rapid inflation of inflatable equipment is required. This is often achieved by way of a combustion reaction involving the generation of gas. Where equipment requiring such inflation relates to non-motorised air travel activities it must necessarily be of lightweight construction and easily transportable. Where such inflation happens in the vicinity of humans the combusted product must also be non-toxic. As the rapid generation of gases thus released into equipment desired to be inflated can give rise to a reaction force that tends to undesirably displace equipment that is particularly sensitive thereto such as those relating to non-motorised air travel activity, it is of importance to ensure that the generation of inflating gases is done in a way that limits the creation of any resultant thrust.

(3) FIELD OF THE INVENTION

According to one aspect thereof the invention relates to a lightweight gas generator device utilisable for inflating inflatable equipment dealing with bodily safety amongst other applicable in situations where equipment weight is particularly relevant. According to another aspect the invention relates to safety enhancing gear dealing with bodily safety associated with bodily- suspended non-motorised aerial travel, as fitted with the gas generator device. Although not so limited the invention finds particular use for serving a safety enhancing function in the field parachuting and paragliding.

(4) PRIOR ART DESCRIPTION

The provision of compressed medium under circumstances where it enhances the safety factor in parachuting, paragliding or the like is presently achieved by way of compressed agent held in containers that is used for releasing gas into inflatable equipment associated with providing additional lift. A disadvantage of so containing such agent is found in the weight of such containers being counterproductive as weight is an important factor under the circumstances of parachuting and the like. Another way of providing a source that can be used to provide additional lift deals with the collection of air in a bag or the like on the movement of a parachute, paraglider or the like through air. The air so collected and held at the ready for distribution as lift enhancing means is, however, at a low pressure thus having a slow reaction time while also being unable to provide substantial additional lift. It is, amongst others an object of this invention to address these issues.

(5) BRIEF DESCRIPTION OF THE DRAWING

The invention is now described, by way of example, with reference to the accompanying drawings. In the drawings

Figure 1 shows a schematic perspective view of a gas generator device in accordance with a first aspect the invention, as fitted to safety enhancing gear, in accordance with a second aspect of the invention,

Figure 2 shows the gas generator device in schematic sectioned side elevation,

Figure 3 shows in schematic side view one embodiment the safety enhancing gear according to the second aspect of the invention, in the form of an airbag layout, in partially deployed state,

Figure 4 shows a schematic side view of the airbag layout as fully deployed,

Figure 5 shows a schematic frontal view of the airbag layout as deployed according to figure 3,

Figure 6 shows a schematic rear view of the deployed airbag layout,

Figure 7 shows in diagrammatic spread out plan view another embodiment of the safety enhancing gear in the form of a canopy deployment booster used for boosting the deployment or redeployment of the canopy of aerial travel equipment in the form of a parachute, _:

Figure 8 shows in diagrammatic side elevation the booster of figure 7 as operatively filled with combustion gas and fitted to a parachute as deployed during descent,

Figure 9 shows in detail the central part of the booster as carrying the gas generator,

Figure 10 shows in diagrammatic spread out plan view another embodiment of the canopy deployment booste used for boosting the deployment- or redeployment of the canopy of a paraglider, and

Figure 11 shows in diagrammatic side elevation the booster of figure 10 as operatively filled with combustion gas and fitted to a paraglider thus supplementing its lift during flight. (6) DETAILED DESCRIPTION OF THE DRAWINGS

With reference to Figures 1 and 2 of the drawings, a gas generator device in accordance with the first aspect of the invention is generally indicated by the reference numeral 10.

The gas generator device 10 comprises a cartridge generally indicated by reference numeral 12, containing a pyrotechnic charge 14 and igniting means for remotely igniting the pyrotechnic charge.

The cartridge 12 is in the form of a cylindrical metal tube 16 formed at opposite ends with combustion gas settling chambers 18. The chambers 18 are in gas flow communication with an axially formed combustion chamber 20 formed within the charge 14, as annularly lining the casing 22 of the tube 16, via gas outlet nozzles extending along ports 24 divergingly opening up in the chambers 18. The inner walls of the chambers 18 are formed by end plates 26 that naturally also close off the combustion chamber 20 and the charge 14 from the settling chambers 18 otherwise that via the nozzles 24, as thus formed through the plates 26. The outer walls of the chambers 18 are formed by bulkheads 28 sealably fitting onto the casing 22. The charge 14 is blanked off from the casing 22 via an annular protecting shell 30.

Escaping of gas generated by the combustion reaction for inflating inflatable equipment takes place via a plurality of discharge outlets in the form of circumferentially arranged passages 32 formed through end flanges 34 forming part of the casing 22. The flanges 34 are of adequate length in the axial direction of the device 10 to cause the passages 32 to extend capillary fashion. The passages 32 are suitably situated relative to one another to limit the possibility of the creation of any resultant thrust on the device 10 once in use by being arranged in pairs thus facing one another alongside the side of the tube 16.

The thrust generated by the discharge of combusted gas passing through the passages 32 thought the one end flange 34.1 is thus counteracted by the thrust, generated by the discharge from the opposite flange 34.2.

The pyrotechnic charge 14 is in the form of a nitrocellulose/nitroglycerine mixture or composite based pyrotechnic charge that is relatively non-toxic and cool burning and that produces gases consisting mainly of nitrogen and a mixture of carbon dioxide, carbon monoxide and water. The theoretical combustion temperature of the pyrotechnic charge is in the order of 1200K with a conventional burn time of between 1 and 3 seconds.

Although not so limited the igniting means is conveniently of an electrical type and includes two igniter switches 36 that are connected to an electrical power source such as a battery (not shown) and to the pyrotechnic charge 1 via electrical conductors 38. As a safety precaution both switches 36 must thus be activated simultaneously to ignite the pyrotechnic charge 14.

Once ignited the combustion gases are produced in the combustion chamber 20 and flow in opposite directions along the ports 24 into the settling chambers 18. The object of the diverging shape of the nozzles extending along the ports 24 is mainly to attain and maintain the correct combustion pressure in the combustion chamber 20. Control of this pressure controls the combustion rate of the pyrotechnic charge and ensures combustion stability.

Expanded combustion gases thus pass to the settling chambers 18 via the ports 24. Thermodynamic expansion along the ports 24 results in a primary cooling of the combustion gases en route to the chambers 18. Further convection and conduction cooling of expanded gases takes place in the settling chambers 18 resulting in a substantially cooled product entering the discharge passages 32. A final cooling of combustion gases takes place along the passages 32 owing to their relative length that is supplemented by the secondary expansion of the gases on being discharged to the equipment desired to be inflated. Should gases entering the equipment intended for inflation still be too hot, an annular conventional heat sink such as in the form of sintered metal particles can be located in each of the settling chambers 18 over the divergent nozzles of the ports 24.

Referring to figures 1 and 3 to 6 and in another aspect of the invention safety enhancing gear comprises an inflatable arrangement in the form of an airbag layout generally indicated by reference numeral 40. The layout 40 comprises a plurality of airbag fitted with a gas generator device 10 (of which the exact position is not shown in these drawings) for enabling the rapid inflation of the airbags, that are secured to body suspending non-motorised aerial travel equipment such as a paraglider, via risers lines 41. The layout 40 incorporates a harness (not shown) by means of which it is attached to a user's body and for also tying it to the lines of the glider. The layout 40 incorporates semi-rigid rear protection means in the form of a semi rigid seat 42 on which the wearer is seatable and to which the harness is secured, a back and side protective airbag 44 that extends around the back and sides of a person wearing the airbag layout 40, a frontal trunk impact protection airbag 46 and head impact protecting airbag 48 as attached to the airbag 46. The impact protection airbag 46 is preferably independently inflatable of the back and side protective airbag 44. When inflated it is disposed in front of a wearer's trunk for protection against frontal impact. The airbag 48 protects the neck and head region of a wearer once deployed and is operable to deploy in response to partial depressing of the frontal trunk impact protection airbag 46. This happens when the airbag 48 is partially depressed as a result of an impact. The head impact protection airbag 48 is formed with an opening 50 to permit airflow over a wearer's face thus preventing suffocation once deployed. The back and side protective airbag 44 is secured to the wearer's body by means of the harness ( not shown). The riser lines 41 are also secured to the harness to tie the layout 40 to the paraglider.

The back and side protective airbag 44 and the frontal trunk impact protection airbag 46 comprise the main airbags while the head impact protection airbag 48 is inflated, in use, with combustion gases from the frontal trunk impact protection airbag 46 when the latter is depressed partially due to impact. A pressure-regulating device (not shown) is conveniently provided for regulating the flow of combustion gases from the frontal trunk impact protection airbag 46 to the head impact protection airbag 48.

The rate of inflation or deflation of the airbags of the layout 40 is conveniently controllable by means of valves (not shown). The separate airbags of the layout 40 are attached to each other in a way that resists separation of the airbags from one another upon impact, once in use.

The airbags of the airbag layout 40 are configured so that their deployment would automatically force the wearer of the layout 40 into an appropriate injury-restricting parachute landing fall (abbreviated as "PLF") position. The airbag layout 40 can be either manually or automatically activatable. In the latter case it is in response to a predetermined increased tension being applied to the bridles of the reserve parachute (which is a standard component of paragliders) when its deployment occurs.

The airbag layout 40 provides effective protection against impact injuries caused by bad landings in paragliding. It also provides a simple, aerodynamic, lightweight non-restrictive fully circumferential impact regulating arrangement, which allows the pilot of a paraglider to maintain maximum control while forcing such person into a PLF position immediately prior to impact.

In another embodiment of the second aspect of the invention and referring to figures 7 to 11 the safety enhancing equipment is in the form of a canopy deployment booster generally indicated by reference numeral 60 for boosting the deployment or redeployment of the canopy of aerial travel equipment in the form of a parachute, paraglider or the like once used in conjunction therewith. The booster 60 incorporates a flexible non-porous gas distributor 62 that is in gas flow fashion connected to a flexible and inflatable gas tube layout 64 formed with a plurality of gas flow tubes 66 extending in gas flow fashion from the distributor 62. The distributor 62 of the booster 60 is fitted with a gas generator device 10 for inflation of the booster 60. The booster 60 can either be maintained in inflated form once inflated or can be permitted to slowly deflate. When permitted to deflate it can either be fitted with a manually controllable valve layout (not shown) or it can be allowed to automatically deflate at a rate slower that its charging rate via the device 10 by having the tubes 66 suitably perforated (not shown).

In referring to figures 7 to 9 the distributor 62, when the booster 60 is intended for use with a parachute 68, is centrally situated with the gas flow tubes 66 radiating therefrom. The layout 64 also incorporates a circumferentially extending gas tube 70 into which the tubes 66 open up. This arrangement promotes the attainment and maintenance of a uniform pressure throughout the booster 60 once the device 10 is activated. It also ensures that the booster 60 maintains a generally fixed configuration once inflated. The dimensions of the booster 60 are naturally selected to cause the gas tube 70 to lie along the brim of a parachute 68, as shown in figure 8, once the booster 60 is inflated.

Although not shown the booster 60 can incorporate two booster triggering pull cords of which the one is attached to the centre point of a canopy once the gear is fitted to a parachute and the other to the point at which such parachute is attached to a body being parachuted for activating the device 10.

In referring to figure 10 and 11 and when the booster 60 is intended for use with a paraglider 72 the gas tubes 66 of the layout 64 extend finger fashion relative to the distributor 62 while including upstream cross tubes 74 extending laterally from the distributor 62. When operatively fitted the tubes 74 extend along the leading edge of the paraglider 72 with the other gas tubes 66 extending rearward along the paraglider 72.

Claims

(7) CLAIMS

(1) A lightweight gas generator device (10) utilisable for inflating inflatable equipment dealing with bodily safety amongst other applicable in situations where equipment weight is particularly relevant comprising a pyrotechnic charge (14) that produces a gas when combusted, a cartridge (12) presenting a charge containing central chamber along which the charge (14) is fitted to cause the formation of a linearly extending combustion chamber (20) extending between opposite gas outlet nozzles (24) divergingly opening up into combusted gas settling chambers (18) situated at opposite ends of the combustion chamber (20) each in turn presenting at least one discharge outlet (32) via which gas generated by the combustion reaction, once the charge is ignited, becomes discharged to inflate equipment in conjunction with which the device (10) is used, once so involved, and igniting means (36) via which the charge is remotely ignitable, characterised in the discharge outlets (32) being suitably situated relative to one another to limit the possibility of the creation of any resultant thrust on the device that would otherwise have tended to urge it to move in a specific direction.

(2) A gas generator device as claimed in claim 1 in which the discharge outlets (32) of opposite settling chambers (18) are situated to direct combustion gases exiting there from towards one another.

(3) A gas generator device as claimed in claim 1 or claim 2 in which the cartridge (12) is formed with a number of pairs of axial ly-extending discharge outlets (32) extending in the form of discharge passages.

(4) A gas generator device as claimed in claim 3 in which the discharge passages (32) are in the form of long and narrow capillary tubes thus providing long narrow discharge passages that promote the cooling of combustion gases en route to equipment intended to be inflated by the device once in use, through conduction heat transfer with the walls of the cartridge.

(5) A gas generator device as claimed in any one of the preceding claims in which the charge (14) is fitted to the cartridge to cause it to annularly fit the combustion chamber (20) as thus extending about the central axis of the device.

(6) A gas generator device as claimed in claim 5 in which the cartridge (12) is formed with opposing end plates (24) at each end of the combustion chamber (20) each forming the inner wall of its settling chamber (18) through the centers of which the gas outlet nozzles (24) are provided.

(7) A gas generator device as claimed in any one of the preceding claims in which the charge (14) is in the form of a relatively non-toxic and cool burning substance that produces gases consisting mainly of nitrogen and a mixture of carbon dioxide and carbon monoxide and water.

(8) A gas generator device as claimed in claim 7 in which the charge (14) is in the form of a nitrocellulose/nitroglycerine mixture or composite based pyrotechnic charge.

(9) A gas generator device as claimed in any one of the preceding claims in which the cartridge (12) is of a material having an adequately high thermal conductivity to assist in the cooling of combustion gases generated during use of the device while flowing from the combustion chamber, through contact with the cartridge.

(10) Safety enhancing gear dealing with bodily safety associated with amongst others bodily- suspended non-motorised aerial travel comprising an inflatable arrangement (40, 60) that is fitted with a gas generator device (10) in a way that enables the rapid inflation of the arrangement once the device is triggered and which arrangement is securable, even if permanently, to appropriate body suspending non- motorised aerial travel equipment to cause it to perform a safety enhancing function once such equipment, as in use, requires such, the gas generator device (10) comprising a pyrotechnic charge that produces a gas when combusted, a cartridge presenting a charge containing central chamber along which the charge is fitted to cause the formation of a linearly extending combustion chamber extending between opposite gas outlet nozzles divergingly opening up into combusted gas settling chambers situated at opposite ends of the combustion chamber each in turn presenting at least one discharge outlet via which gas generated by the combustion reaction, once the charge is ignited, becomes discharged to inflate equipment in conjunction with which the device is used, once so involved, and igniting means via which the charge is remotely ignitable while its discharge outlets are suitably situated relative to one another to limit the possibility of the creation of any resultant thrust on the device that would otherwise have tended to urge it to move in a specific direction.

(11 ) Safety enhancing gear as claimed in claim 10 in which the discharge outlets of opposite settling chambers of the gas generator device are situated to direct combustion gases exiting there from towards one another.

(12) Safety enhancing gear as claimed in claim 10 or claim 11 in which the cartridge of the gas generator device is formed with a number of pairs of axially-extending discharge outlets extending in the form of discharge passages.

(13) Safety enhancing gear as claimed 12 in which the discharge passages of the gas generator device are in the form of long and narrow capillary tubes thus providing long narrow discharge passages that promote the cooling of combustion gases en route to equipment inflated by the device once in use through conduction heat transfer with the walls of the cartridge.

(14) Safety enhancing gear as claimed in any one of claims 10 to 13 in which the charge of the gas generator device is fitted to the cartridge to cause it to symmetrically surround the combustion chamber as thus extending about the central axis of the device.

(15) Safety enhancing gear as claimed in claim 14 in which the cartridge of the gas generator device is formed with opposing end plates at each end of the combustion chamber each forming the inner wall of its settling chamber though the centers of which the gas outlet nozzles are provided.

(16) Safety enhancing gear as claimed in any one of claims 10 to 15 in which the charge is in the form of a relatively non-toxic and cool burning substance that produces gases consisting mainly of nitrogen and a mixture of carbon dioxide and carbon monoxide and water.

(17) Safety enhancing gear as claimed in claim 16 in which the charge is in the form of a nitrocellulose/nitroglycerine mixture or composite based pyrotechnic charge.

(18) Safety enhancing gear as claimed in any one of claims 10 to 17 in which the cartridge is of a material having an adequately high thermal conductivity to assist in the cooling of combustion gases generated during use of the device while flowing from the combustion chamber, through contact with the cartridge.

(19) Safety enhancing gear as claimed in any one of claims 10 to 18 in which the inflatable arrangement is in the form of an airbag layout (40) incorporating at least one inflatable airbag that is formed to protect a person's body by extending to an adequate extent along the length of such body while suitably surrounding it from a position in the vicinity of its head to a position near its feet, once inflated, for limiting the possibility of impact injuries resulting on landing with aerial travel equipment in the form of a parachute, paraglider or the like as fitted with the gear.

(20) Safety enhancing gear as claimed in 19 in which the airbag layout includes semi-rigid rear protection means (42).

(21) Safety enhancing gear as claimed in 20 in which the airbag layout (40) includes a back and side protective airbag (44) which, when inflated, extends around the back and sides of a person wearing the airbag layout (40).

(22) Safety enhancing gear as claimed in claim 21 in which the airbag layout includes a frontal trunk impact protection airbag (46) that is independently inflatable of the back and side protective airbag (42) and which, when inflated, is disposed in front of a wearer's trunk thereby to protect the front of the wearer's body below the head and neck, from frontal impact.

(23) Safety enhancing gear as claimed in claim 22 in which the airbag layout includes a head impact protection airbag (48) which, when deployed, protects the neck and head region of a wearer.

(24) Safety enhancing gear as claimed in 23 in which the head impact protection airbag (48) is operable to deploy in response to the frontal trunk impact protection airbag (44) being partially depressed as a result of an impact.

(25) Safety enhancing gear as claimed in any one of claims 10 to 18 that is in the form of a canopy deployment booster (60) for boosting the deployment or redeployment of the canopy of aerial travel equipment in the form of a parachute, paraglider or the like once used in conjunction therewith, which booster incorporates a flexible non-porous gas distributor (62) that is gas transfer fashion connected to a flexible and inflatable gas tube layout (64) incorporating at least one but depending on the equipment in conjunction with which the booster is intended to be used, a number of flexible and inflatable gas tubes (66, 70) arranged to cause the gas tube layout to take on the shape of a canopy in conjunction with which the booster (60) is intended to be used, the gas generating device (10) being suitably held relative to the distributor (62) to result in gas released by the combustion reaction once the device is triggered to be released within the distributor (62) and from there to flow into the gas tube.

(26) Safety enhancing gear as claimed in 25 in which the gas tube layout (64) is formed to release gas received from the distributor (62), once the booster is used, at a pre-determined rate of flow that is adequately slower that the flow rate of gas from the distributor to enable the booster to effectively perform its boosting function.

(27) Safety enhancing gear as claimed in claim 26 in which the gas tube layout (64) is formed to release gas received from the distributor by being appropriately porous.

(28) Safety enhancing gear as claimed in claim 26 in which the gas tube layout (64) is formed to release gas received from the distributor by way of strategically placed outlets.

(29) Safety enhancing gear as claimed in any one of claims 25 to 28 in which the distributor (62) is centrally situated with respect to the gas tube layout (64) thus being employable to be used for boosting the canopy of a parachute with the canopy deployment booster being securable on either side of such parachute.

(30) Safety enhancing gear as claimed in claim 29 that is fitted with two booster triggering pull cords of which the one is attached to the centre point of a canopy once the gear is fitted to a parachute and the other to the point at which such parachute is attached to a body being parachuted.

(31) Safety enhancing gear as claimed in claim 30 or claim 31 in which the gas tube layout (64) incorporates circumferentially (70) and radially (66) extending gas tubes of which the latter are gas flow fashion connected at their ends remote from the distributor (62) to the circumferentially extending tube (70) with the layout being arranged to cause the circumferential tube to be situated on the brim of the canopy of a parachute once the gear is operatively fitted, the layout (64) thus promoting the attainment of a uniform pressure once the gear is operatively used thereby assisting in the proper deployment of the parachute.

(32) Safety enhancing gear as claimed in any one of claims 25 to 28 in which the gas tube layout (64) is formed with gas tubes (66) that extend generally finger fashion relative to the distributor (62) to the effect of extending transverse along the leading edge of a paraglider from the distributor, as thus centrally situated, and rearward from the transverse extending tubes (74) to an adequate extent along the body of such paraglider, once the gear secured thereto, to enable the performance of an effective safety enhancing function.