GB2281377A - A gas generator arrangement - Google Patents

A gas generator arrangement Download PDF

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Publication number
GB2281377A
GB2281377A GB9317853A GB9317853A GB2281377A GB 2281377 A GB2281377 A GB 2281377A GB 9317853 A GB9317853 A GB 9317853A GB 9317853 A GB9317853 A GB 9317853A GB 2281377 A GB2281377 A GB 2281377A
Authority
GB
United Kingdom
Prior art keywords
gas generator
tube
gas
diffusion
generator arrangement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9317853A
Other versions
GB2281377B (en
GB9317853D0 (en
Inventor
Dan Persson
Lars-Gunnar Skoette
Joakim Landen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Autoliv Development AB
Original Assignee
Autoliv Development AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Autoliv Development AB filed Critical Autoliv Development AB
Priority to GB9317853A priority Critical patent/GB2281377B/en
Publication of GB9317853D0 publication Critical patent/GB9317853D0/en
Publication of GB2281377A publication Critical patent/GB2281377A/en
Application granted granted Critical
Publication of GB2281377B publication Critical patent/GB2281377B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/264—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic
    • B60R21/2644—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/261—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow with means other than bag structure to diffuse or guide inflation fluid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/263—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using a variable source, e.g. plural stage or controlled output
    • B60R2021/2633—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using a variable source, e.g. plural stage or controlled output with a plurality of inflation levels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/264—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic
    • B60R21/2644—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder
    • B60R2021/2648—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder comprising a plurality of combustion chambers or sub-chambers

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Air Bags (AREA)

Abstract

A gas generator arrangement for inflating an air-bag comprises a diffusion tube (1) having diffusion apertures (2). Two gas generators (6, 7) are mounted on the outer periphery of the tube, with gas outlets in communication with the interior of the tube, by means of bolts (4) which extend diametrically across the tube and which are associated with a clamping plate (14). A guard (10) mounted on the gas generator housings may trap part of the air-bag against the exterior of the tube (1). <IMAGE>

Description

DESCRIPTION OF INVENTION "INPROVENENTS IN OR RELATING TO A GAS GENERATOR ARRANGEMENT" THE PRESENT INVENTION relates to a gas generator arrangement and more particularly relates to a gas generator arrangement adapted to supply gas to inflate an air-bag provided in a motor vehicle.
It has been proposed to provide an air-bag in a motor vehicle adapted to be inflated in the event that an accident should occur, the inflated air-bag providing a cushion to protect the driver of the vehicle or a passenger in the vehicle.
An air-bag of this type must be inflated relatively rapidly once an accident is detected by an appropriate sensor. It has therefore been proposed to utilise one or more pyrotechnic charges to inflate an air-bag.
In particular, it has been proposed to provide a tubular diffuser, associated with the pyrotechnic charges, the diffuser being initially located in the folded or uninflated bag to direct gas from the pyrotechnic charges to the interior of the bag. A typical diffuser consists of a tubular element with a plurality of diffusion apertures provided in the wall of the tubular element, with two pyrotechnic charges, one being located at each end of the tubular element.
With an arrangement of this type, if one charge is activated before the other charge, it is possible that the gas generated by the first charge will create a shock wave within the diffuser tube, sufficiently large to physically dislodge the second charge from its mounting at the end of the tube. Also, it is conceivable that if two charges are located facing each other, the charges being located at opposed ends of a diffuser tube, the shock wave generated when one charge is activated could actually serve to extinguish combustion of the other charge.
The present invention seeks to provide an improved shock tube arrangement in which at least two charges are provided associated with one diffuser tube.
According to this invention there is provided a gas generator arrangement, the gas generator arrangement comprising a perforated diffusion tube and at least two generator elements, the gas generator elements being mounted on the outer periphery of the perforated diffusion tube on the same side of the axis of the tube, the gas generator elements having gas outlets in communication with the interior of the diffusion tube.
Preferably the gas generator elements are held in position by a clamping plate which engages the gas generator elements and clamps the gas generator elements against the peripheral exterior of the tube, the clamping plate being held in position by at least one bolt which extends through the clamping plate, and diametrically across the tubular element, the bolt engaging part of the tubular element which is diametrically opposed from the gas generators.
Conveniently there are two gas generators and three said bolts are provided.
A gas generator in accordance with the invention may form a gas generator for an air-bag, part of the airbag being secured to the diffuser element by being clamped against the exterior of the tubular element by a guard carried by the gas generator housings.
Preferably the diffusion tube does not have any diffusion apertures opposite the said gas outlets.
In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompany drawings in which FIGURE 1 is a perspective exploded view of the components of the gas generator arrangement in accordance with the invention, and FIGURE 2 is a side view illustrating the components of Figure 1 in the assembled condition.
Referring initially to Figure 1 of the drawings an elongate diffuser tube 1 is illustrated. The diffuser tube is provided with a plurality of diffusion holes 2 provided in the side wall of the tube.
In the centre of the tube the peripheral exterior of the tube is provided a rectangular cut-out 3 defining an inlet port to the tube. Three bolts 4 are provided having threaded shanks which extend upwardly through the cutout 3. The heads 5 of the bolts engage the under-side of the tube, and the threaded shanks of the bolts extend diametrically across the interior of the tube before passing upwardly through the rectangular cut-out 3.
Two gas generator housings 6,7 are provided, each containing an appropriate pyrotechnic charge. Each gas generator housing is of cylindrical form and is provided, at its upper end, with a recess 8,9 adapted to contain a triggering squib or the like. A gas outlet is provided at the lower end of each housing, and these outlets will be in communication with the interior of the tube when the housings have been mounted in position as will now be described. The housings 6,7 are inter-connected by a rectangular guard 10 which is arcuate in cross-section.
The radius of curvature of the guard is slightly more than the radius of the tube 1. The housing 6,7 are mounted on the longitudinal axis of the guard 10. The guard 10 is also provided with three apertures 11,12,13 dimensioned to receive the threaded shanks of the bolts 4. The apertures 11, 12 and 13 are provided at the axis of the guard 10, and are evenly spaced, the aperture 12 being located between the gas generator housings 6 and 7, and the apertures 11 and 13 being located towards the end of the guard 10.
A clamping plate 14 is provided of elongate oval configuration, the clamping plate defining axially located spaced apart apertures 15,16 which are dimensioned and positioned to be aligned with the recesses 8,9 in the housings 6,7 adapted to receive the squibs. The plate 14 further defines axially located small apertures 17,18,19 adapted to be co-aligned with the apertures 11, 12 and 13 and also being dimensioned to receive the threaded shanks of the bolts 4.
Three nuts 20,21,22 are provided adapted to cooperate with the shanks of the bolts 4.
Turning now to Figure 2 it can be seen that the guard 10, with the gas generator housings 6,7 is initially mounted in position over the shanks of the bolts and firmly abuts the exterior of the tube 1. If desired, an air-bag can be trapped between the cover 10 and the exterior of the diffuser tube 2, the air-bag being held in position by the guard 10.
The clamping plate 14 is then located in position, with the threaded shanks of the bolts for passing through the apertures 17,18,19. The clamping plate is then positioned with the apertures 15 and 16 aligned with the recesses 8 and 9 formed in the gas generator housings 6 and 7. Nuts 20,21,22 can the be mounted in position at the exposed ends of the threaded shanks of the bolts 4, thus tightening the clamping plate in position and firmly retaining the gas generators in position. The gas generators are thus mounted on the outer periphery of the diffusion tube, and are not mounted at the opposed ends of the diffusion tube.
It is to be noted that there are no diffusion apertures 2 formed in the region of the diffuser tube 1 directly opposite the lower ends of the gas generator housings 8 and 9. Thus, between the adjacent bolt heads 5 there are no diffusion apertures. This helps ensure that no gas from the gas generators directly leaves the diffusion tube 1, but all of the gas is diffused or has its direction of flow changed before leaving the diffuser tube 1.
The ends of the diffuser tube may be open or may be closed, or may be constricted having an opening in an end closure plate, the opening being of lesser diameter than the diameter of the interior of the diffuser tube 1.
In operation of the gas generator arrangement illustrated in Figures 1 and 2, the two gas generators 6 and 7 may be activated simultaneously or may be activated successively. Gas from the gas generators will flow through the inlet port constituted by the cut-out 3 into the interior of the tube. The gas flows along the tube, and diffused gas passes through the diffusion hole 2.
There is virtually no risk that the ignition of one gas generator will either cause the separation of the other gas generator from its intended position and also, since the gas generators are directed in the same direction and do not face each other, there is only a minimum risk that the ignition of one gas generator will actually extinguish the other gas generator.
The use of transverse bolts extending across the diffusion tube helps ensure that the gas generator housings are held very firmly in position relative to the diffuser tube.
The gas generators present in the gas generator housings 6 and 7 may be triggered by a squib located within the recess 8,9 provided for that purpose. The squib may be activated either by an electric signal, the squib then being an electrically ignited squib, or being ignited by a shock supplied to the squib by a shock tube.
It is to be appreciated that in the described embodiment of the invention the gas generators are mounted to engage the outer periphery of a tubular diffuser element, in contrast to engaging the ends of a tubular diffusion element. The gas generators are all located on the same side of the axis of the diffuser tube, and consequently do not interfere with each other.

Claims (7)

CLAIMS:
1. A gas generator arrangement, the gas generator arrangement comprising a perforated diffusion tube and at least two generator elements, the two gas generator elements being mounted on the outer periphery of the perforated diffusion tube, on the same side of the axis of the tube, the gas generator elements having gas outlets in communication with the interior of the diffusion tube.
2. A gas generator arrangement according to Claim 1 wherein the gas generator elements are held in position by a clamping plate which engages the gas generator elements and clamps the gas generator elements against the peripheral exterior of the tube, the clamping plate being held in position by at least one bolt which extends through the clamping plate, and diametrically across the tubular element, the bolt engaging part of the tubular element which is diametrically opposed from the gas generators.
3. A gas generator arrangement according to Claim 2 wherein there are two gas generators and three said bolts are provided.
4. A gas generator arrangement according to any one of the preceding Claims forming a gas generator for an airbag, part of the air-bag being secured to the diffuser element by being clamped against the exterior of the tubular element by a guard carried by the gas generator housings.
5. A gas generator arrangement according to any one of the preceding Claims wherein the diffusion tube does not have any diffusion apertures opposite the said gas outlets.
6. A gas generator arrangement substantially as herein described with reference to and as shown in the accompanying drawings.
7. Any novel feature or combination of features disclosed herein.
GB9317853A 1993-08-27 1993-08-27 Improvements in or relating to a gas generator arrangement Expired - Fee Related GB2281377B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9317853A GB2281377B (en) 1993-08-27 1993-08-27 Improvements in or relating to a gas generator arrangement

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9317853A GB2281377B (en) 1993-08-27 1993-08-27 Improvements in or relating to a gas generator arrangement

Publications (3)

Publication Number Publication Date
GB9317853D0 GB9317853D0 (en) 1993-10-13
GB2281377A true GB2281377A (en) 1995-03-01
GB2281377B GB2281377B (en) 1997-04-23

Family

ID=10741139

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9317853A Expired - Fee Related GB2281377B (en) 1993-08-27 1993-08-27 Improvements in or relating to a gas generator arrangement

Country Status (1)

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GB (1) GB2281377B (en)

Also Published As

Publication number Publication date
GB2281377B (en) 1997-04-23
GB9317853D0 (en) 1993-10-13

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20000827