DE2358134A1 - SEAT BELT SYSTEM FOR TRANSPORTATION EQUIPMENT, IN PARTICULAR VEHICLES - Google Patents

Description

TAKATA KOJYO GO.LTD .., No. 28 Sakuragawa-'cho, Nishikubo Shiba, Minato- ^ ku, Tokyo _t Japan

Safety belt system for means of transport, in particular vehicles

The invention is concerned with locking devices on vehicle seat belt systems, in particular with a drum lockout coil control system associated with an inertia switch.

To avoid injuries to occupants on vehicle seats as possible To keep it small, the occupants are usually in restrained to the seat by a waist belt, by a shoulder belt, or by both, so that the occupant with a collision or sudden positive or negative acceleration of the vehicle out of the seat is not thrown out. Of course, under normal driving conditions it is highly desirable that the occupant retains full freedom of movement and that he is restrained in the seat only in emergencies, i.e. when abnormal driving conditions occur, i.e. especially when suddenly accelerating or suddenly decelerating of the vehicle. There have already been a great many

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Belt restraint systems proposed that use the seat belt Wind up spring-driven, which is normally freely removable, but then automatically locked against pulling out when sudden acceleration occurs. With such a system a drum is used which is blocked or released by activation controlled by an inertial switch or deactivation of an associated coil. An important disadvantage and a particular inadequacy this system is based on the type of inertia switch. Such switches are usually very bulky and unreliable and work very slowly and, moreover, are not adjustable; in addition, they are not very adaptable and also leave many wishes unfulfilled in other ways. A typical inertia switch works with a pendulum, whose function depends on the pendulum mass, the pendulum length and the deflection, with a smaller or more compact Structure of the switch no setting of the correct or optimal relationship between the parameters mentioned permitted. In contrast, the invention is based on the object of a control system which operates with inertial forces for the blocking reel of a seat belt winding drum to create that overcomes the disadvantages mentioned, also works very reliably, compact Has structure, has a high response speed and is robust, adjustable and extremely versatile is.

To this end, the invention proposes an inertia switch that is used for controlling a drum blocking coil Seat belt retraction reel is particularly suitable and has a bearing with a seat recess in which rests an inertia ball in a normal rest position and from it depending on a predetermined one Acceleration of the camp to an advanced position

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passes over and actuates an electric peeler * Advantageously, the inertia switch has a vertical, insulated housing on its bottom a metallic bearing element provided with the seat houses and a vertically adjustable top contact has, the recessed face on the metal ball resting in the seat. It turns out as expedient to make the ball so large that you Diameter is 20 mm *, where "the diameter of the circular seat about 10 mm and the resting gap between the ball and the upper contact piece between o, o7 and 1.3 mm, preferably about 1.0 mm, for these Dimensions, the value of the response acceleration results experimentally to about 0.5 g, and if that: vehicle one Suffering acceleration of 1,000g / s is the switch response speed 2-3 milliseconds, which is much less than the values you get at other inertia switches encountered, the response angle was about 30. -

The switch is used to power a coil, which in turn controls the blocking of a belt winding drum, and is advantageously connected to the input of a stabilized semiconductor amplifier, the output of which is connected to the blocking coil, the phase is selected so that it The blocking coil is activated or deactivated according to the actuation of the inertia switch, depending on whether the drum is blocked when the coil is activated or when the coil is deactivated. The amplifier ¹ further contains a delay network which can keep the coil in the blocking phase for a predetermined time interval following the release or opening of the inertia switch. The inertia switch and the amplifier are advantageously in a small package

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closed, which is fixed in the vehicle. and the overall resulting device is extremely compact, reliable, robust and easy to use Structure and easy to install and also shows an extremely short response time.

The invention is described below with reference to the accompanying figures. Show in detail:

1 is a perspective and, in some places, diagrammatic view of the having the features of the invention equipped drum locking system ;

Figure 2 is a cross-section along line 2-2 of Figure 1;

Fig. 3 one of the Fig. similar representation of a slightly modified inertia switching device;

FIG. 4 shows a representation of another, similar to FIG. 2 Embodiment of the inertia switch;

Figure 5 is a perspective view of the system, partially broken away, embodying the preferred features of the invention;

Figure 6 is a perspective view of a partially broken away inertial switch from the system of Figure 5;

Figure 7 is a cross-section along line 7-7 of Figure 6; Fig. 8 is a circuit diagram of the drum control circuit; and

FIG. 9 shows an illustration similar to FIG. 7 of a further one Embodiment of the invention.

Figures 1 and 2 show above all the basic embodiment of the invention, the inertia switch for determining a predetermined positive or negative acceleration of the vehicle or a predetermined one Vehicle inclination is used and has a cylindrical housing 1 made of insulating material with a bottom, which is at the top is closed by a lid or a cap 2.

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A cylindrical upper metal contact 3 with a horizontal one The bottom side is vertical through a connector 6 adjustable, which protrudes through the cap 2 and releasable by a locking nut at the set height is determinable. In the bottom of the housing 1, an annular bottom contact is embedded, which has a metal seat 4 has a circular central depression. A steel ball 5 of larger diameter than the recess in the "seat 4 rests normally in the seat 4 in the. Depression, so that as a result of a predetermined acceleration or tilt of the housing 1, the ball 5 due to its moment of inertia leaves its rest position in seat 4 and the upper contact piece 3 with the lower contact piece 4 short-circuits. The 'ball 5 and the contact pieces 3 and 4 are advantageous with a corrosion-resistant, electrically very good conductive material, coated or vapor-deposited, for example with gold chrome, copper or the like., With 3 and 4 leads extending from the contact pieces. ·

The contacts 3 ^ and 4 are with the input connections a circuit for controlling the power supply to the trip coil for the locking pawl or brake of a seat belt winding drum C of construction not of interest here, the drum under Spring loading winds the belt and prevents it from being pulled off The belt is blocked, depending on the activation or deactivation the spool so that the drum can be said to be released or locked. The control network comprises a semiconductor amplifier switch A and a delay circuit B, which are so related that when the inertia switch is closed, the control circuit is triggered so that it blocks the coil causes the drum and the drum a predetermined time interval after the opening of the inertia switch

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holds blocked, depending on the time constant of the delay network .

The dimensions and the interrelationships of the ball with the contact pieces 3 and 4 are given above. In operation, the housing 1 is fixed vertically in the vehicle so that as a result of a predetermined vehicle acceleration or tendency, the ball 5 causes the contact pieces 3 and 4 to short-circuit, whereupon immediately the drum C is blocked and the occupant is restrained on the seat, so that he is only slightly Injuries, if any, will be sustained.

The inertia switch shown in Fig. 3 acts in

essentially like the inertia switch according to FIG. 2 and differs from this only in that the The lower surface of the contact piece 3 is spherically hollowed out, concentric to that in the seat 4 in the rest position stationary ball 5.

The inertia switch shown in Fig. 4 differs from the inertia switches shown in FIGS. 2 and 3 in that the contact piece 3 by a Microswitch has been replaced. In detail is a Microswitch. 7 arranged in the upper part of the housing 1 and comprises a switching arm which is arranged very close to the ball 5 resting in the seat 4, so that the microswitch 7 is actuated by the ball 5 when leaving the seat 4 as a result of a predetermined acceleration or inclination. The connections of the microswitch 7 are connected to the input of the control circuit.

Reference is now made to Figs. 5-8, which illustrate in detail a preferred embodiment of the invention explained and in which the reference numeral 26 generally

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denotes a magnetically lockable drum of otherwise of no interest design, the spring-loaded drum from the side arms of a U-shape Migen fastening clamp is rotatably carried and wears toothed washers, in the spring-loaded pawls 32 for Locking of the drum against rotation in one direction can intervene ", which is the direction of withdrawal of the seat belt 30 on the drum. An armature moved by a coil 28 is connected to the pawls 3-2 and pulls the pawls back when current flows in the coil 28 and releases the drum for the withdrawal of the belt 30. Is used to control the flow of current through the coil 28 a control section 27 with a small housing 33, this to facilitate attachment in the vehicle is provided with flanges 34. An inertia switch 38 and a control circuit 35 sit on an insulating Chassis 37 and are enclosed in a suitable housing 33 made of polymeric resin, so that a results in a compact, robust unit.

The inertia switch 38 is located in a cylindrical Housing made of electrically insulating material, for example in the form of synthetic, organic polymer resin, the fastening ears protruding outwards at the bottom 10 has an upright positioning of the Allow housing bottom. A lower contact piece 11 in the form of a circular metal seat is attached to the housing bottom inside the housing 9, wherein on the contact piece on its upper side a coaxial, cylindrical recess is formed, which has an upper peripheral circular seat edge 21. A metallic one Coupling pin 12 extends through the housing wall into seat contact 11 and leads to an outer one Line 13. A steel ball 20, 'which is preferably made with a very good electrically conductive metal, such as chrome or gold

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is coated, sits on the recess, usually only on the edge 21, as the ball

20 has a larger diameter than the diameter of the edge 21, as already mentioned above.

A metal bushing 15 is pushed into the upper part of the housing 9 and fastened there and has between their End an integrally formed transverse wall having an axially extending cut bore 16 owns. A metal pin 19 extends through the housing wall into the socket 15 and leads on its outer End to a line 23. An upper circular metallic contact piece 17 is displaceable on the lower part of the socket 15 and has an axially upwardly extending screw pin 18, which in the bore 16 engages and exposed at its upper End has a slotted head for a screwdriver. A circular coaxial recess is on the bottom of the contact piece 17 and shows a circular lower contact edge 22, which is the seat edge

21 corresponds. A cylindrical locking nut 14 rests in the upper part of the socket 15 and engages the screw, pin 18. The gap between the on the seat edge 21 resting ball 20 and the contact edge 22 can be adjusted so that the desired switch sensitivity and the above-mentioned operating parameters can be achieved, which can be achieved by loosening the nut. 14, setting the Pin 18 and then tightening the lock nut 14 can be done.

According to FIG. 8, the control _{circuit has six transistors T to T fi} , the transistors T. and T ″ being interconnected in a Darlington circuit and their output connected to a four-stage amplifier comprising the transistors T to T g in the usual way is.

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The operation of the amplifier with the transistors T to T _fi does not require any further explanation. The voltage input for the amplifier is stabilized by a parallel connection of a reverse-polarized diode B T- and a capacitor C1 and the amplifier output is stabilized by connecting the collector of the output _transistor T fi to the high-voltage line via a varistor V and to ground is connected via a parallel circuit of a reverse polarity diode D2 and a capacitor C2.

The base of the input transistor T. is connected to ground via a series circuit of a current-limiting resistor Rl and the inertia switch 38 using the switch feeds 13 or 23 and is connected to the live, high-level line via an RC circuit, which consists of a parallel circuit Resistor R2 and a capacitor R3 consists. The collector of the transistor T ₁ is connected to ground via a resistor R3 and its emitter is connected to the high line via a resistor and capacitor, which are connected in parallel. The collector of the output transistor T 1 is connected via the coil 28, which is shunted by the varistor V, to the terminal of the battery which is not connected to ground.

Under normal operating conditions of the system described so far, the inertia switch 38 is open and keeps the transistor T _r highly conductive through the transi-

disturb T ^ to T ₅ , so that the coil 28 is fully activated, ie remains energized, whereby the pawls 32 are withdrawn and the drum 26 is released so that the belt 30 can move freely. However, in an abnormal operating condition, such as that usually associated with a collision, which manifests itself as an abrupt change in driving

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represents the speed of the vehicle or in the form of a sudden inclination of the vehicle, the inertia of the ball 20 drives it into the position 20 '(FIG. 7), in which it contacts the edges 21 and 22 and electrically connects them, so that the inertia switch 38 at least momentarily closed is. Closing the switch 38 immediately charges the capacitor C3 and sends a signal to the transistor T ', the base of which switches off the transistor T due to the transistor stages connected in between. The blocked transistor T _fi causes a deactivation (current flow interruption) for the coil 28, so that the pawls 32 come into resilient engagement with the drum toothed disks and block the drum so that the belt cannot be pulled off. When the switch 38 is opened, the amplifier _{will leave the output transistor T fi} blocked and the drum 26 blocked due to the charge on the capacitor C3, which maintains the amplifier input signal at a sufficient level to block the transistor T. When the capacitor C3 is sufficiently discharged after a predetermined time interval, which depends in detail on the RC time constant of the resistor R2 in connection with the capacitor C3, the input signal for the transistor T ^ is no longer large enough to block the transistor T _fi hold so that

er very quickly returns to its conductive state and allows current to flow through the coil 28, whereby the Drum 26 and thus the belt 30. are released.

Note that the drum lock-up response time of the described system is about 15 to 18 milliseconds, calculated from the moment of the collision, which is only half as long as the time that is determined in other systems. It should be further noted that the bearing of the ball is only at the seat

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Edge 21 is extremely beneficial because it is too a much faster response, greater reliability and a more compact design, with the upper contact edge further enhances these advantages and by the way the use of the inertia switch too then enabled when it is rotated 180 °.

The drum 26 is of the type that it is activated by activation the spool 28 is blocked against pulling off the belt, although the system described last is also blocked an amplifier can be operated by omitting the transistor T. containing stage and by Connect the collector of transistor ^ T- '^ directly to the base of transistor T "is modified. In all other respects, the systems are similar to one another.

Figure 9 shows a modified embodiment of the inertia switch which can be used to advantage in place of the inertia switch illustrated in Figures 5-8 is; distinguishes this new embodiment, differs from the previous inertia switch in that the underside of the upper adjustable contact piece . is trained differently. .

In particular, the modified inertia switch 50 has an upper contact piece 51 corresponding to the contact piece 17, which has a downwardly extending conical bottom surface 52 with a lowermost tip 53 which is .koaxial to the ball 20 on the seat. The contact piece 51 has a coaxial screw pin 18 as in the last embodiment, which advantageously allows an adjustment of the contact piece 51 up to "a gap of about 0.1 mm between the upper contact tip 53 and the ball 20, the above dimensions and parameters are similar to those of the above-described embodiment ^: "'--- -.

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In all other features, the two embodiments are similar, so that the same reference numerals are the same Designate parts.

Overall, an inertia switch for controlling the locking of a safety belt winding drum has been described, which has a seat with a circular recess in which a steel ball rests; a switch trigger arm or a contact piece is suspended above the ball and can move vertically so, be set so that a sudden acceleration of the switch establishes an electrical connection between the Seat and the upper contact piece caused, due to the inertial movement of the ball or the triggering of the switching arm by the ball. The switch is via a semiconductor amplifier with the locking coil connected to the belt drum so that the release of the inertia switch locks the drum in place; The amplifier contains an RC delay circuit which locks the drum over a predetermined Time interval after the release by the inertia switch lets persist.

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Claims (5)

A η s p r ü c h e Qsafety belt system m with an inertia switch One of the preceding claims, characterized by a seat belt take-up Trcimmel; by a blocking device for the drum, which is movable between a blocking position and a release position is; by a coil (28) which the blocking device (32) in the blocking position and in the Can pivot release position depending on the current flow through the coil; as well as by a control device that responds to the position of the ball in the switch, which controls the current flow through the coil '. 2. System according to claim 1, characterized in that the control device comprises a semiconductor _{amplifier (T, .... T fi} ), the output of which is connected to the coil and the input of which is connected to the inertia switch, with the amplifier, the coil, when the inertia switch is closed controls in such a way that the blocking device is brought into the blocking position. 3. System according to claim 2, characterized in that the semiconductor amplifier is an RC delay circuit having the amplifier after releasing the inertia switch a predetermined time interval in a Holds state in which the blocking device in the Blocked position is. 4Q9817 / Ö923 4. System according to claim 3, characterized in that the switch and the control circuit are housed in a common housing. 5. System according to one of the preceding claims,
characterized in that the underside of the contact piece has a conical configuration with the tip (53) of the cone pointing downwards. 409817/0923 4Γ . L e r s e i t e