CA1316767C - Event sequence indicator - Google Patents

Event sequence indicator

Info

Publication number
CA1316767C
CA1316767C CA000552745A CA552745A CA1316767C CA 1316767 C CA1316767 C CA 1316767C CA 000552745 A CA000552745 A CA 000552745A CA 552745 A CA552745 A CA 552745A CA 1316767 C CA1316767 C CA 1316767C
Authority
CA
Canada
Prior art keywords
primer
gas
vehicle
vessel
axis
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.)
Expired - Fee Related
Application number
CA000552745A
Other languages
French (fr)
Inventor
David S. Breed
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.)
Breed Automotive Technology Inc
Original Assignee
Breed Automotive Technology Inc
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 Breed Automotive Technology Inc filed Critical Breed Automotive Technology Inc
Application granted granted Critical
Publication of CA1316767C publication Critical patent/CA1316767C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G07CHECKING-DEVICES
    • G07CTIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C5/00Registering or indicating the working of vehicles
    • G07C5/08Registering or indicating performance data other than driving, working, idle, or waiting time, with or without registering driving, working, idle or waiting time
    • G07C5/0816Indicating performance data, e.g. occurrence of a malfunction
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60RVEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags

Landscapes

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

Abstract

ABSTRACT OF THE DISCLOSURE
A miniature device for indicating if an airbag inflator for a vehicle was set off in an accident. The device records the movement of a ball in an enclosed tube. The record is made when the tube is collapsed around the ball in response to pressure or heat from the activated primer.

Description

1 3 1 6 7 G ' FIELD OF TH~ I~VENTION

The invention relates to airbags for vehicles. More particularly it relates to devices which determine if the airbag was set off in an accident~

BRIEF D~SCRIPTION OF THE PRIOR ART

Airbags have proven effective in preventing drivers and passengers from being impaled on steering columns, smashed against dashboard and ejected through windshields during vehicular accidents. However in several cases of cars equipped with airbags where the airbags have been deployed, the driver of the vehicle has claimed that the airbag went off inadvertently and caused him to have the accident. There have been reports of inadvertent deployments of the airbags caused by radio interference.
Present airbag systems have no device for positively determining whether the airbag was set off by the sensor in response to an accident at the time the airbag was deployed or if it somehow went off by itself. This information is essential in determining the manufacturer's liability in the event the passenger asserts that an airbag caused the accident. The correct determination of liability is vital to the manufacturer's survival.

~k ,~

1 3 1 67 ', ~

Some airbag systems have a diagnostic system which indicates whether an electrical current was sent to the inflator after an accident was sensed, but this does not positively indicate that the gas generator was started after an accident occurred.
A device has been disclosed in Patent No. 3,915,474 by ~eld et al for solving this problem. This "recording mechanism for a safety device used in a motor vehicle" has not been adopted due primarily to its large size. A recording mechanism of this type to be usable must not contribute significantly to the size or weight of the airbag system. Any attempt to miniaturize this device, however, results in a problem that in some vigorous crashes the piston will rebound off the end of the cylinder and return to its initial position before the gases from the inflator have had time to arrest the motion of the sensing mass. Thus, in a miniaturized version, the device can give a false reading. The problem arises from the fact that it takes as much as 15 milliseconds from the time the sensor has indicated that the airbag should be deployed and the time that there is significant gas pressure in the inflator.
The present invention represents an improvement over the prior art described in Patent No. 3,915,474 in that it uses the primer or squib gas to stop the motion of the sensing mass or pistons. This gas pressure is available in 1 to 2 milliseconds after sensor firing.

1 31 67'7 SUMMARY OF_T~E_INVENTI~N

The principal object of the present invention is to provide a miniature device which indicates that an automobile was in an accident at the time the airbag was deplo~ed.
Another object of the invention is to provide a miniature device which independent of the crash sensor indicates that an automobile was in an accident at the time the airbag was deployed. This will provide correct information in the event that the sensor itself was defective.
An additional object is to provide a means for positively ruling out the manufacturer's liability when an airhag is deployed during the course of an accident.
An additional object of this invention is to provide a method of determining whether a vehicle was in a crash when deployment of a safety device was initiated.
Yet another object of the present invention is to be designed as small, lightweight, and relatively inexpensive to manufacture and assemble.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However for a better understanding of the invention, its advantages, and objects attained by its use, reference should be had to the drawings which form a further part hereof, and to the accompanying descriptive matterr in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION O~ TH~ DRAWI~S

In the drawings, in which like reference numerals indicate corresponding parts throughout the several views:
FIGURE 1 is a view showing an airbag mounted on a vehicle steering wheel and in the dashboard;
FIGURE 2 is a cutaway of the airbag system with the gas generator broken away and removed;
FIGURE 3 is a cross-section view of an inflator with t.he event sequence indicator inside the sensor which is, in turn, inside the inflator;
FIGURE 4 is a view taken of the outside of a preferred embodiment of the event sequence indicator of the present invention;
FIGURE 5 is a view taken of a preferred embodiment of the present invention showing the rest condition; and FIGURE 6 is a view taken of a preferred embodiment of the present invention showing the invention after the inflator has been activated in response to an accident.
While the invention will be described in conjunction with an example embodiment, it will be understood that it is not intended to limit the invention to such embodiment. On the contrary, it is intended to cover all al'ernatives, 1 31 ~7'`7 modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

D~TAILED D~SCRIPTION OF TH~ P~EFERRED EMBODIME~T

In the drawings, an airbag safety restraint system 7 includes a gas generator 8 mounted interiorly inside the housing 9 for the folded airbag 12. Interior to the gas generator 8 is an event sequence indicator 10.
Reference is now made to FIGURE 4 which shows a cutaway view of the event sequence indicator 10 in the resting condition. The indicator is a tube 20 containing a ball 30 and a spring 40. The tube has a flange 50 to assist in positioning the tube inside the gas generator (inflator) of an airbag.
A preferred embodiment of the event sequence indicator consists of an aluminum tube 20 one inch long, approximately 1/8 inch internal diameter closed at both ends.
Inside the tube is 1/8 inch stainless steel ball 30 and a spring 40 which exterts a force on the ball greater than 1 G.
The clearance between the ball and the tube is at least .003 inches, so that the tube can be made by conventional manufacturing techniques. The tube is placed inside the inflator near to the primer or squib, which could be also inside the sensor if the sensor is in the inflator, at such a location that when the primer chamber becomes pressurized the 1 31 67~7 tube is subjected to the primer gas pressure. The tube is aligned in the inflator such that the axis of the tube lies substantially along the axis of the vehicle. If the inflator is in the steering column, for example, the axis of the tube would be parallel to the axis of the steering column.
During an accident, the car decelerates causing the ball to move forward in the tube compressing the spring. As long as the car is experiencing a deceleration in excess of the force exerted by the spring on the ball, the ball will move away from its original location. If the primer then is ignited, the gas pressure in the primer chamber will collapse the thin walled aluminum tube trapping the ball as shown in FIGURE 2. Thus, for example, if the primer went off inadvertently and there was no deceleration of the automobile, the ball would be trapped at its start position. If on the other hand, the car is decelerating above 3 G's and therefore definitely in an accident, the ball would be trapped away from its home position.
This device which would add only a few cents to the cost of the airbag system in a very simple manner solves a problem, which if done external to the inflator, requires a separate sensor and some complicated circuitry.
Naturally, many other systems could be designed using other spring mass systems such as band and roller devices, pendulums, etc. and other environments in the primer chamber could be used to trap the sensing mass, such as heat. If the 1 31 67/~7 mass were surrounded in plastic for example the heat of the primer could deform the plastic ko trap the sensing mass.
Also, a pressure sensor having an electrical output such as a Piezo electric device, or pressure switch, or a temperature sensor could be placed in the primer chamber and used in combination with an accelerometer to detect the simultaneous presence of gas pressure or temperature in the primer chamber and deceleration of the vehicle. An electronic circuit employing a fuse or other recording means, for example, would record if the vehicle is decelerating when pressure or temperature first appears in the primer chamber. Although more complicated then the preferred embodiment, it nevertheless still gives a more accurate indication of which event occurred first, deceleration of the vehicle or ignition of the primer.
Accidents were simulated using the NHTSA (National Highway Traffice Safety Administration) and the embodiment which is described. The clearance between the ball and tube for this device was .006 inches. The ball had the capability of travelling .625 inches before rebounding off the compressed spring. The spring gave an initial bias of 2.3 G's, which increased as the ball travelled down the tube to a maximum of 8 G's if the ball reached its maximum travel of .625 inches.
The simulations were run by first determining the time that a typical passenger compartment sensor would have fired on each of the crashes. Three milliseconds were added to this firing time to give the approximate time that pressure 1 ~1 67'7 would appear in the primer chamber. The simulation model was then run and the travel of the event sequence indicator ball was recorded at the times determined above. Table I shows the results of the 20 simulations. The first column gives the trial number; the second column gives the crash description;
the third column gives the distance travelled by mass at the time the pressure collapsed the tube, and the fourth column gives the results of simulations where 15 milliseconds were added to the firing time. This device would have given a false indication in cases 4, 7, 14, 15, and 16 if the inflation pressure was used instead of the primer pressure.

TABL~ I

Distance 15 Crash Description(Inches)Milliseconds 1. 39.9 mph, VTB #10.262 0.154 Chevrolet Citation 1980 2. 29.9 mph, VTV #10.299 0.433 Chevrolet Impala 1978 3~ 30.1 mph, VTV #10.288 0.368 Chevrolet Impala 1978 4. 48.0 mph, VTB #10.256 0.000 Chevrolet Citation 1980 5. 35.0 mph, VTB #10.244 0.389 Chevrolet Citation 1980 6. 34.9 mph, ITV #10.262 0.446 Volkswagen Rabbit 1979 1 31 67~'`

T~BLF 1 Continued ...
7. 34.8 mph, VTB #1 0.268 0.044 Volkswagen Rabbit 1979 8. 59.1 mph, ITV #2 0.246 0.575 Ford Torino 1975 9. 62.3 mph, VTV #1 0.235 0.341 Dodge Sportsman Van 1979 10. 62.3 mph, VTV #2 0.273 0.199 Chevrolet Impala 1979 11. 40.7 mph, VTB #1 0.275 0.230 Plymouth Fury 1975 12. 25.2 mph, VTB #1 0.276 0.152 Dodge Sportsman Van 1979 13. 45.1 mph, VTB #1 0.262 0.228 Volvo 244 1975 14. 25.1 mph, VTB #1 0.254 0.055 Ford Van 1979 15. 62.2 mph, ITV #2 0.249 0.025 Honda Civic 1975 16. 63.6 mph, VTV #1 0.295 0.015 Ford Torino 1979 17. 63.3 mph, VTV #2 0.259 0.264 Chevrolet Impala 1979 18. 40.5 mph, VTB #1 0.257 Ford Torino 1975 19. 40.8 mph, VTB #1 0.215 Honda Civic 1975 20. 30.0 mph, VTB #1 0.261 Ford Van 1979 * VTB = Vehicle to Barrier ITV = Impactor to Vehicle VTV = Vehicle to Vehicle Only these cases where the airbag would have been deployed were 1 31 67~
considered.
From the results here, as well as 280 cases studied, we see in all cases this ball travels in excess of 0.15 inches at the time that it would be frozen by the collapsing tube and thus would have indicated a crash was in progress.
For purposes of this disclosurel the term primer has been used to include the primary inflator initiating pyrotechnic device. As such, it would include stab primers which are used in mechanically initiated inflators such as disclosed in Patent No. 4,580,810 issued to Breed and electric squibs used in electrically initiated airbag systems.
Thus, the aforenoted objects and advantages of the invention are most effectively obtained. Although, one somewhat preferred embodiment has heen disclosed and described herein, it should be understood that this invention is in no sense limited thereby, and its scope is to be determined by that of the appended claims.

Claims (15)

1. A device for indicating if an airbag inflator for a vehicle was set off in an accident which comprises:
(a) a vessel enclosed at both ends which inserts into an airbag inflator housing, said vessel has an axis which is substantially aligned with the axis of said vehicle;
(b) an object capable of moving along said axis of said vessel in response to a deceleration of said vehicle as it decelerates in excess of a predetermined level;
(c) a means for exerting a force on said object to prevent it from moving along said axis unless said vehicle decelerates in excess of a predetermined level; and (d) a means for entrapping said object during its movement along said axis of said vessel, said means prevents said object from further movement once a primer within said inflator is activated.
2. The device of claim 1 in which said means for exerting a force is a spring.
3. The device of claim 1 in which said predetermined level is 2.3 G's.
4. The device of claim 1 in which said means for entrapping said object is the collapsing of said vessel in response to the gas pressure generated by said primer inside said inflator housing prior to inflation of said airbag.
5. The device of claim 4 in which said vessel is a thin gauge metal.
6. The device of claim 5 in which said metal is aluminum.
7. The device of claim 5 in which said vessel is plastic.
8. The device of claim 1 in which said means for entrapping said object is the collapsing of said vessel in response to the heat generated inside the inflator during inflation of said airbag.
9. The device of claim 1 in which said vessel is a tube and said object is a ball.
10. The device of claim 9 in which said ball is stainless steel.
11. The device of claims 1, 4 or 8 in which said object is a pendulum.
12. The device of claims 1, 4 or 8 in which said object is a band and a roller device.
13. A diagnostic device for use in conjunction with a gas generator comprising:
means for sensing pressure caused by a primer gas;
means for sensing deceleration; and recording means to record that deceleration was occurring when pressure caused by actuation of the primer gas appeared, said primer gas being physically separate from said gas generator's interior both before and after activation of the primer gas.
14. An indicator for determining that a vehicle was crashing when deployment of a safety device was initiated comprising:
means for sensing that a vehicle is in a crash;
means for sensing initiation of a primer gas used to initiate said safety device; and means for recording that the crash provided the primer gas initiator, said primer gas being physically separate from said safety devices interior both before and after initiation of the primer gas.
15. A method for determining that a vehicle was crashing when deployment of an airbag inflator was initiated comprising:
providing an object capable of moving along an axis which is substantially aligned with the axis of said vehicle in response to deceleration of said vehicle in excess of a predetermined level; and recording the position of said object when gas pressure is generated by initiation of a primer gas, said primer gas being physically separate from said safety devices interior airbag inflator's interior both before and after initiation and the primer gas.
CA000552745A 1986-11-26 1987-11-25 Event sequence indicator Expired - Fee Related CA1316767C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US93539486A 1986-11-26 1986-11-26
US935,394 1986-11-26

Publications (1)

Publication Number Publication Date
CA1316767C true CA1316767C (en) 1993-04-27

Family

ID=25467042

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000552745A Expired - Fee Related CA1316767C (en) 1986-11-26 1987-11-25 Event sequence indicator

Country Status (7)

Country Link
JP (1) JPH0649437B2 (en)
CA (1) CA1316767C (en)
DE (1) DE3739440C2 (en)
FR (1) FR2607084B1 (en)
GB (1) GB2198571B (en)
IT (1) IT1211536B (en)
SE (1) SE469330B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2307970B (en) * 1995-12-08 1998-03-18 Toyota Motor Co Ltd Method for identifying an unactuated state/actuated state of the inflator
DE29812627U1 (en) 1998-07-08 1999-01-07 TRW Airbag Systems GmbH & Co. KG, 84544 Aschau Gas generator

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3572141A (en) * 1967-11-15 1971-03-23 Atomic Energy Commission Roller-band devices
US3714627A (en) * 1971-10-20 1973-01-30 Gen Motors Corp Vehicle inflatable cushion actuation and monitoring circuit
JPS5147213B2 (en) * 1972-02-09 1976-12-14
JPS5212456B2 (en) * 1972-02-09 1977-04-07
JPS5147214B2 (en) * 1972-02-09 1976-12-14
GB1454289A (en) * 1972-12-23 1976-11-03 Messerschmitt Boelkow Blohm Tell-tale device for use with safety apparatus protecting vehicle occupants in a collision
JPS5636093B2 (en) * 1973-03-16 1981-08-21
JPS5413986B2 (en) * 1973-06-05 1979-06-04
JPS5195331A (en) * 1975-02-17 1976-08-20
DE2513023A1 (en) * 1975-03-25 1976-10-07 Daimler Benz Ag SENSOR RELEASED BY DELAY FORCE
US4167276A (en) * 1976-12-17 1979-09-11 Allied Chemical Corporation Self-contained air bag system
JPS5811338B2 (en) * 1978-08-10 1983-03-02 本田技研工業株式会社 air bag device
US4470302A (en) * 1982-06-21 1984-09-11 Carte Norman E Indicating shipping accelerometer
US4580810A (en) * 1984-02-15 1986-04-08 Breed Corporation Air bag system
US4561675A (en) * 1984-04-02 1985-12-31 Morton Thiokol, Inc. Auto ignition device

Also Published As

Publication number Publication date
IT1211536B (en) 1989-11-03
JPH0649437B2 (en) 1994-06-29
JPS63227442A (en) 1988-09-21
GB2198571A (en) 1988-06-15
GB2198571B (en) 1991-01-09
SE8704661D0 (en) 1987-11-25
DE3739440C2 (en) 1998-10-22
SE8704661L (en) 1988-05-27
IT8767984A0 (en) 1987-11-17
SE469330B (en) 1993-06-21
GB8727487D0 (en) 1987-12-23
FR2607084B1 (en) 1996-05-03
FR2607084A1 (en) 1988-05-27
DE3739440A1 (en) 1988-07-21

Similar Documents

Publication Publication Date Title
US4573706A (en) Passenger compartment sensor requiring substantial velocity change
US6334639B1 (en) Bumper equipped with shock-absorbing means
CA1238065A (en) Non crush zone-all mechanical damped sensor
US4167276A (en) Self-contained air bag system
US4166641A (en) Inflator for safety air bag in an automotive vehicle
US5033569A (en) Airbag crash protection
US5054810A (en) Vehicle with a safety system
JP2549878B2 (en) Collision sensor device
US4706990A (en) Mechanical impact sensor for automotive crash bag systems
CA1316767C (en) Event sequence indicator
EP0733513A1 (en) A vehicle impact sensor arrangement for detecting a side impact
US4848792A (en) Event sequence indicator
CA1238066A (en) Passenger compartment sensor with low bias
US4715617A (en) Passenger compartment sensor with low bias
JPH0834312A (en) On-vehicle air bag system
US6015162A (en) Restraint system for passengers in vehicles
WO1992019476A1 (en) A vehicle impact sensor arrangement
CN219214789U (en) Automobile seat system and vehicle
US5454590A (en) Vehicle impact sensor arrangement
KR0151670B1 (en) Clash detective sensor of vehicle airbag
EP1203702B1 (en) Safety system with a plurality of expandable and releasable protective elements
GB2290058A (en) Stick-on airbag actuated by bodily impact or by proximity sensor
JPH08268208A (en) Batch loading type air bag module for side-face collision, mounting method to said car,generating method of said gas, supply of said power and diagnostic method thereof
Nwagboso Development of Toyota airbag sensor and system
Martin et al. Preliminary vehicle tests-inflatable occupant restraint systems

Legal Events

Date Code Title Description
MKLA Lapsed