CA1116149A - Re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices - Google Patents

Re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices

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Publication number
CA1116149A
CA1116149A CA286,923A CA286923A CA1116149A CA 1116149 A CA1116149 A CA 1116149A CA 286923 A CA286923 A CA 286923A CA 1116149 A CA1116149 A CA 1116149A
Authority
CA
Canada
Prior art keywords
retightening
liquid medium
safety device
safety
container
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
Application number
CA286,923A
Other languages
French (fr)
Inventor
Artur Fohl
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.)
TRW Repa Feinstanzwerk GmbH
Original Assignee
TRW Repa Feinstanzwerk GmbH
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 TRW Repa Feinstanzwerk GmbH filed Critical TRW Repa Feinstanzwerk GmbH
Priority to CA286,923A priority Critical patent/CA1116149A/en
Application granted granted Critical
Publication of CA1116149A publication Critical patent/CA1116149A/en
Expired legal-status Critical Current

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Abstract

Abstract of the Disclosure A retightener for safety-belt automatic wind-up devices having an energy converter having a charge, which when activated in the case of danger, the explosive pressure of the fired charge acts on a retightening element which tightens the safety-belt around the body of the motor vehicle passenger. The retightener of the invention has an intermediate liquid medium transmitting the explosive pressure of the charge arranged between the charge and the retightening element.

Description

~6149 Background of the Invention Field of the Invention The invention relates to a retightener with a pyrotechnical charge for safety-belt automatic wind-up devices having an energy converter, wherein the explosive pressure of the fired charge acts, in the case of danger, on a retightening element which tightens the safety belt around the body of the motor vehicle passenger to be protected.

Description of the Prior Art Retighteners of the type with a pyrotechnic propellant charge serve to eliminate belt looseness, in the case of danger, by pulling back the belt, so that the belt fits the body of the passenger to be protected as closely as possible and the free forward fall up to the point that the belt becomes effective is kept as small as possible.

In one known design of retlghtener, a pi5ton guided ln a tight cylinder wlth its piston rod engaging the safety belt with its free end, is displaced in the cylinder, in the case of danger, by the explosive pressure of a pyrotechnical charge, and the belt is thereby retightened. `~
~ .
Rotary tighteners which are combined with the automatic wind-up are also known. In such devices the explosive pressure of the pyrotechnic propellant charge drives a turbine wheel which is fastened on the shaft of an automatic wind-up.

The so-called linear tighteners, which work with a piston guided in a cylinder, have the disadvantage that they have only a relatively small retightening travel distance, compared to the relatively large volume they occupy. In order to be effective the linear tighteners must be tightly sealed and this requires a great deal of effort as well as adding materially to the cost.
The effect of the known rotary tighteners in practice was found insufficient to adequately retighten the belt because the pressure of the explosion can be transmitted to the turbine wheel only with low efficiency.
Summary of the Invention An object of the invention is to provide a retightener with pyrotechnic propellant for safety-belt automatic wind-up devices with substantially increased efficiency, particularly in the case of rotary retighteners, and with reduced cost of sealing.
With the foregoing and other objects in view, there is provided in accordance with the invention a safety device for a vehicle for restraining an occupant of a vehicle during a colli-sion, the safety device comprising a belt winding device including support means for attachment to a vehicle, the belt winding device including a rotatable member, a safety belt for restraining an occupant during a collision, the safety belt being attached to the rotatable member and wound thereon upon rotation of the rotatable member in one direction, means for tightening the safety belt around the occupant in response to a collision, the means comprising a retightening element connected with the rotatable member to rotate the rotatable member in the one direction upon movement of the retightening element in the one direction, a pyrotechnic propellant charge for generating an explosive pressure in response to a coilisicn, a liquid con-tainer for connection with the vehicle and disposed intermediate the retightening element and the pyrotechnic propellant charge, the container having a liquid medium disposed therein and an out-let disposed for directing the liquid medium from the container against the retightening element for driving the retightening element in the one direction~ and means for causing the explo-sive pressure to act on the liquid medium and to force the liquid medium to exit from the container through the outlet and act on the retightening element to drive the retightening ele-ment in said direction for tightening the safety belt around the occupant.
The retightening element may be a turbine wheel and the container may include at least one blast nozzle aligned in the driving direction of the turbine wheel in a region opposite the pyrotechnic charge.
The blast nozzle may be closed off by a rupture disc.
The container containing the intermediate liquid medium may have the shape of a cylinder, and a propulsion piston may be disposed between the pyrotechnic propellant charge and the inter-mediate liquid medium.

The rotatable member may be a shaft which is connected at one end to the turbine wheel and the cylinder containing the intermediate liquid medium may have its axis parallel to the shaft.
The propulsion piston may be secured in its rest position by a shearing element.
The propulsion piston may have a pressure equalization nozzle.
The container containing the intermediate liquid medium may have an opening closed off by the charge.
The container containing the intermediate liquid medium may have the form of a helical or spirally bent tube.

~6~A9 Although the invention is illustrated and described herein as embodied in a re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices, it is never-theless not intended to be limited to the details shown, since various modifications may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The invention, howeverl together with additional objects and advantages thereof will be best understood from the following description when read in connection with the accompanying draw-ings, in which:
PIG. 1 shows a side view of an automatic wind-up device with a built-on liquid container and a turbine wheel; and FIG. 2 is a top view of the automatic wind-up device of FIG. 1 with the liquid container shown in cross section; and FIG. 3 is an automatic wind-up device according to FIG. 1 with a helical tube as the liquid container; and FIG. 4 is an automatic wind-up device according to FIG. 1 with a tube spirally wound around the turbine wheel as the liquid container.
Detailed Description of the Invention Examples of rotary retighteners in accordance with the invention are shown in the drawings.
In an automatic wind-up device of conventional design shown in FIGS. 1 to 4, a turbine wheel 5 is firmly mounted on a free end 2 of the shaft 4 on which the safety belt 3 is wound and unwound.
In FIGS. 1 and 2, a container 7 which contains an intermediate liquid medium and has the form of a hollow cylinder~
is combined with the automatic wind-up device 1 in a structural ~, ~ lLl&~L4~gt unit. A pyrotechnic propellant charge 8 is arrarlged at one end of the cylinder. Between the charge 8 and the intermediate liquid medium 6 a propulsion cylinder 9 is secured in its rest position by a shearing element 10 which will yield on activation of the charge. The end opposite the charge is designed as a blast nozzle 11, which is closed off by a rupture disk 12 and is aligned in the driving direction of the turbine wheel.
When the charge 8 is ignited via the ignition cable 13, the shearing element 10 is destroyed and the propulsion piston 9 is pushed against -the intermediate liqu:id meclium 6. This pressure destroys the rupture cdisk 12 and the intermediate liquid medium 6 is ejected as a directed jet under high pressure in the drive direction against the turbine wheel 5, which is thereby set in 11161'19 rotation, rewinding the belt 3 on the shaft 4J taking up the slack of the belt.

This arrangement is particularly advantageous i~ the automatic wind-up device comprises an energy converter, as in that case, the desired energy conversion for relieving the load on the protected person takes place immediately.

In the example according to FIG. 3, the liquid container i5 designed in the form of a helical tube ]4, the physical arrange-ment of which is similar to that of the container 7 in FIG. 2.
The charge 8 with the ignit~on cable 13 is arranged at one end 15 of the tube 14, while the other tube end 16 is desi~ned as a blast nozzle with a rupture disk 12. The propulsion piston is unnecessary in this embodiment.

.,,............................................................... 1-In the embodiment according to FIG. 4, a tube containing the intermediate liquld medium is bent into a spiral 17, which surrounds the turbine wheel 5 concentrically. The charge 8 with the ignitlon cable 13 is again arranged, similarly to the embodiment according.to FIG. 3, at one end o~ the tube and the other end 18 i~ designed as a blast nozzle~

The operation of the embodlments shown in FIGS 3 and 4 is `
the same as the operation of the embodiment example according ,:
to FIGS. 1 and 2.

i

Claims (9)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A safety device for a vehicle for restraining an occupant of a vehicle during a collision, said safety device comprising a belt winding device including support means for attachment to a vehicle, said belt winding device including a rotatable member, a safety belt for restraining an occupant during a collision, said safety belt being attached to said rotatable member and wound thereon upon rotation of said ro-tatable member in one direction means for tightening said safety belt around the occupant in response to a collision, said means comprising a retightening element connected with said rotatable member to rotate said rotatable member in said one direction upon movement of said retightening element in said one direction, a pyrotechnic propellant charge for generating an explosive pres-sure in response to a collision, a liquid container for connection with the vehicle and disposed intermediate said retightening ele-ment and said pyrotechnic propellant charge, said container having a liquid medium disposed therein and an outlet disposed for directing the liquid medium from the container against the retightening element for driving said retightening element in said one direction, and means for causing said explosive pressure to act on said liquid medium and to force said liquid medium to exit from said container through said outlet and act on said retightening element to drive said retightening element in said direction for tightening the safety belt around the occupant.
2. Safety device for a vehicle according to claim 1, wherein the retightening element is a turbine wheel and the container includes at least one blast nozzle aligned in the driving direction of the turbine wheel in a region opposite the pyrotechnic charge.
3. Safety device for a vehicle according to claim 2, wherein the blast nozzle is closed off by a rupture disc.
4. Safety device for a vehicle according to claim 2, wherein the container containing the intermediate liquid medium has the shape of a cylinder and wherein a propulsion piston is disposed between the pyrotechnic propellant charge and the intermediate liquid medium.
5. Safety device for a vehicle according to claim 4, wherein said rotatable member is a shaft which is connected at one end to the turbine wheel and the cylinder containing the intermediate liquid medium has its axis parallel to said shaft.
6. Safety device for a vehicle according to claim 4, wherein the propulsion piston is secured in its rest position by a shearing element.
7. Safety device for a vehicle according to claim 4, wherein the propulsion piston has a pressure equalization nozzle.
8. Safety device for a vehicle according to claim 2, wherein the container containing the intermediate liquid medium has an open-ing closed off by the charge.
9. Safety device for a vehicle according to claim 2, wherein the container containing the intermediate liquid medium has the form of a helical or spirally bent tube.
CA286,923A 1977-09-16 1977-09-16 Re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices Expired CA1116149A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA286,923A CA1116149A (en) 1977-09-16 1977-09-16 Re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA286,923A CA1116149A (en) 1977-09-16 1977-09-16 Re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices

Publications (1)

Publication Number Publication Date
CA1116149A true CA1116149A (en) 1982-01-12

Family

ID=4109560

Family Applications (1)

Application Number Title Priority Date Filing Date
CA286,923A Expired CA1116149A (en) 1977-09-16 1977-09-16 Re-tightener with pyrotechnic propellant charge for safety-belt automatic wind-up devices

Country Status (1)

Country Link
CA (1) CA1116149A (en)

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