GB1565973A - Safety belts - Google Patents

Description

(54) SAFETY BELTS (71) We, AUTOFLUG GMBH, a German Company of Industriestrasse 10, 2084, Rellingen 2, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a safety belt guide fixture particularly for motor vehicle safety belts which are fitted with an automatic reel device. Preferably, the invention is intended for use with three-point belts. In belts of of this kind, the belt runs from a lower fastening fixture on the outside of the seat, initially as a pelvic belt, to a detachable fastening fixture on the inside of the seat, for example on the transmission tunnel, and from there, as a chest belt, diagonally upwards to a guide fixture which is mounted more or less at the level of the head of the person wearing the belt, generally on the middle window pillar of the vehicle body and from there substantially perpendicularly downwards to a point near the fastening fixture mentioned first, where there is provided a belt store in which the belt ends.

The known belt stores are predominantly constructed as self-locking (automatic) reel devices. The blocking may be carried out either as a safety belt and/or vehiclesensitive system.

The invention is based on the following problem; if an accident occurs, the belt is conventionally blocked in or at the reel device, i.e. at a point which is relatively remote from that portion of the belt which is in contact with the body of the person. The consequence of this is that there is a relatively large length of belt between the blocking point and the belt extending over the body of the person, and the extension of this belt which occurs under the effect of the forces occurring in an accident, in addition to the slack which is formed when the belt is put on and the extension of the belt which takes place in the region of the body of the person causes the belt to be lengthened which may allow the body strapped in to move forwards dangerously. However, there is also another important cause of dangerous protractions of the belt, mainly the so called "film spool effect" in the reel device. This means that the belt which is wound in more or less tight coils by the winding spring onto the appropriate shaft could be rolled up substantially more tightly if corresponding forces are applied, so that, with normal winding, as a result of a sharp pull on the belt, a tightening of the coils must take place whilst simultaneously releasing a corresponding length of belt. The length of belt released can be about 10 centimetres, as has been found by experience. Together with the factors of the belt slack and extension already mentioned, in the case of an accident it is readily possible for belt to be extended by about 20 centimetres compared with the normal buckled state. As a result, the head and knees of the person can strike proximate parts of the vehicle.

Therefore, efforts should be made to block the safety belt as near as possible to that portion of the belt which comes into contact with the person's body, and indeed in a manner which does not allow the "film spool effect" to occur.

The recognition of the problem described and solutions for objects relating thereto are already part of the prior art. As can be seen from German Auslegeschrift 2401703 and German Offenlegungschrift 2360160 and 2456105, which describe the problem accurately, it has been recognised that the region of the upper guide fixture on the middle window pillar is regarded as a particularly suitable point for the independent blocking of the belt near the body of the person buckled in. The blocking device is mounted below the fixture, i.e. between the belt winder and the guide fixture.

The disadvantage of the extended length of belt which this involves is eliminated by proposals according to German Offenlegungschrift 2348654 and 2402106, according to which the guide fixture and blocking device are combined to form a single component, and indeed constructional measures are taken to release the blocking or clamping device by means of the effect of the force of the belt on the guide fixture (German Offenlengungschrift 2402106, figure 6).

The present invention starts from this type of a guide fixture on the middle window pillar with an integrated clamping device for safety belts. It is based on the problem of providing the simplest possible fixture of this kind, which can nevertheless exert a strong clamping force and indeed normally, i.e. when no accident has taken place, the smallest possible forces should act on the safety belt, in order to give the person the feeling of maximum freedom of movement and also, if possible, to avoid damage to the textile material as a result of stretching compression or shearing stress.

To solve this problem, the invention uses the per se known lever principle and thus uses a method of construction which has hitherto not yet been used as a middle window pillar guide fixture. U.S. Patent no.

2947353 discloses a construction of this kind, but in fact intended for a different purpose, namely a combined guiding and clamping device for safety belts, with a onearm lever, the free end of which guides the safety belt, whilst near the rotation axis of the lever is mounted the clamping point which can therefore withstand impact of great force. A pull on the belt automatically causes it to clamp, whilst the force of a helical tension spring holding the lever has to be overcome. This construction is indeed simple, but has the disadvantage that the belt pulling and clamping force act on the same lever arm and that this would make it difficult to find spring steel which enables the helical tension springs mentioned above, which are under comparatively very high stress, to be produced economically.

Experience has shown that this spring will gradually become fatigued, and as a result the number of blockages of the belt when the belt is pulled out in the usual way is increased and thus wear on the safety belt will lead to premature damage thereof.

Therefore, another object of the invention is to provide a construction with which the above mentioned spring difficulties can be overcome.

A one-armed lever for wedging a safety belt against a datum plane is also disclosed by U.S. Patent no. 2705529, wherein an electromagnet is provided to move the lever from its open position into its clamped position. This magnet reacts as a vehiclesensitive component, for example by means of a mercury switch, as also disclosed by German Offenlegungschrift 1430422 for similar purposes.

The lever principle for clamping a safety belt which runs off a reel is also disclosed in U.S. Patent no. 3692253. This specification discloses a belt reel device with an integrated clamping device comprising a lever substantially semi-circular in crosssection, which as a whole also serves to guide the belt. In this device, too, the clamping lever acts on the belt with a low damage normal force. Certainly, the disadvantage is that the safety belt itself is exposed to great wear stress, since it has to slide over the greater part of the surface of the lever, and it is particularly disadvantageous that the lever, in its unblocked state, pivots in a way which substantially enlarges the looping angle, thus causing deterioration in the practicability of withdrawal of the belt and hence reducing the freedom of the person.

U.S. Patent no. 3287062 also discloses the blocking of a safety belt by means of a lever action, but the lever is mounted at a distance from the belt reel under the seat.

This lever, which has the form of a noncylindrical roller, also serves at the same time to guide the belt, whilst again the fact that the looping angle is, by comparison, very large and thus the mobility of the belt is poor, must be regarded as a disadvantage.

A guide fixture with an integrated clamping device is also described in German Offenlegungschrift 1480245. Here, too, a lever is provided which has at its upper end a pivotally movable key projection which, when the bolt is pulled out quickly, penetrates between two rods through which the belt also runs, so that the projection clamps the belt in place relative to one of the rods. The lever has two arms, but the arm opposite the key projection serves only to receive a connecting rod which is intended to prevent the lever arm which ensures clamping of the belts from swinging back too far. This is prevented by the rod which then comes into contact with the belt.

The use of ball-controlled switches for the vehicle-sensitive release of blocking devices for safety belts is known form German Auslegeschrift 1430599, German Offenlegungschrift 2362845 and U.S. Patent 2206067 and 2740010. German Offenlegungschrift 1430422 which has already been mentioned discloses particularly numerous variations on releasing devices for electrical switches for blocking safety belts based on positive or negative acceleration forces.

According to the invention there is provided a safety belt guide fixture for a safety belt having an automatic reeling mechanism, comprising a housing adapted to be mounted to a structural part of a vehicle, a lever pivotably mounted in the housing, said lever including a cross member spaced from and substantially parallel to the pivot axis and defining therebetween an aperture through which the belt passes inuse being guided once around the cross member only, from where in the non-clamped position the belt passes without further change of direction to the reeling mechanism in one direction and to the body of an occupant in the other direction, the lever further including a clamping surface by which the belt runs in normal use, the arrangement being such that the lever causes the belt to be clamped between the clamping surface and an associated surface, biasing means being provided for resisting such pivoting of the ever,.

A fixture according to the invention has the advantage of being particularly simple and can also be made quite flat and of very robust construction, which enhances the practical arrangement and safety of functioning of the fixture.

Preferably the lever is in the form of a frame, said cross member forming one side of the frame, projecting shoulders being provided at each end of the cross member for guiding the belt thereover.

In a preferred embodiment the lever is formed as a two-armed lever, the clamping surface being formed on one arm, said biasing means comprising a resilient compression member disposed between the other arm and the housing. However, in an alternative preferred arrangement the lever comprises a single armed-lever extending through an aperture in the housing, the cross member lying outside the housing, the clamping surface being provided on the cross member and the associated surface comprising a lower wall of the aperture, a control shoe in operative association with said biasing means being guided for parallelwise movement within the housing and being pivotably connected to the lever.

In order that the invention may be readily understood certain preferred embodiments will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a view from behind of the passenger seat inside a motor vehicle equipped with a three-point safety belt having a guide fixture according to the invention.

Fig. 2 is a sectional view through a first embodiment of a guide fixture according to the invention, Fig. 3 is a sectional view through a second embodiment, and Fig. 4 is a view similar to Fig. 3 of the fixture in the clamping position.

As shown by figure 1, the three-point safety belt 10 for the passenger seat 11 of the motor vehicle consists of an external lower floor fitting 12, a pelvic belt part 13 proceeding therefrom, a belt fastener 14 with an anchoring cord 16 fastened on the transmission tunnel 15 of the vehicle, a chest belt part 17, an upper guide fixture 18 with an integrated clamping device, a perpendicular belt portion 19 and a belt reel 20. The belt 10 with its portions 13, 17 and 19 consists of a single integral piece which is continuously guided moveably through the fastener 14. The guide fixture 18 with the integrated clamping device is located more or less at the level of the head of a the person strapped in, on or in the middle window pillar 21 of the vehicle bodywork.

The belt portion 19 may also run on or in the pillar, emerging through an aperture provided therein, and, like the belt reel 20, may be mounted either in an exposed or covered position.

Fig. 2 shows in greater detail the guide fixture 18 of fig. 1. The fixture comprises a housing consisting of a sheet metal blank bent into the required shape with a rear wall 22, side walls 23 adjoining it in a U shape and a front wall 24 divided perpendicularly in the centre, which front wall 24 consists of continuations of the side walls 23 bent inwardly. The rear wall 22 is extended upwardly to an attachment 25 with an aperture 26 for a fastening bolt (not shown). In bearing eyelets in the side walls 23 is mounted a shaft 28 on which a twoarmed clamping lever 29 is pivotally mounted. Alternatively the shaft and clamping lever may be made from one piece, the shaft being pivotable. The clamping lever 29 is in the form of a frame and is made from metal as a cast or forged part. On both sides of the boss 30 thereof are mounted the two lever arms 31 and 32, the arm 31 being shorter than the arm 32 and extending downwardly, whilst the arm 32 is upwardly directed.

The longer arm 32 of the clamping lever 29 is provided with a bevel 37 on which is mounted a clamping jaw 33 which has an associated clamping jaw 34 mounted opposite on the front wall 24 of the housing, said clamping jaw 34 being mounted so as to be slightly pivotable about an axis extending at right angles to the direction of withdrawal of the belt, in order to be capable of being set exactly parallel to the jaw 33. It is also possible to fasten the clamping jaw 34 rigidly and the jaw 33 pivotably. The belt 17, 19 travels between the two jaws 33, 34 and from there upwards, where it is guided forwards over a transverse cross member 35 of the clamping lever 29 and diagonally downwards. The transverse member 35 has a correspondingly round smooth surface, over which the belt slides. The transverse member 35 can also be constructed as a roller. In order to prevent the belt from slipping off, lateral shoulders 36 adjoin the transverse member 35, the inner outline of which merges with a comparatively large radius (preferably five to ten times the thickness of belt 17) into the ridge line of the transverse member 35. In the centre of the clamping lever 29, the shorter arm 31 abuts a plastics gas spring cushion 38 which is fastened to the inside of the rear wall 22 of the housing by means of adhesive, for example.

The gas spring cushion 38 consists, in this embodiment, of a block of foam plastics with sealed cells (soft polyvinylchloride foam), the cells being filled with a gas, e.g.

nitrogen. This is a material as sold under the Registered Trade Mark "LYNIZELL" in contrast to foam plastic with open cells, i.e.

of a spongy nature, this material has specific spring properties which can be created as required during manufacture, and moreover this material is distinguished by its comparatively very long and, in particular, fatigue-free life.

The method of operation of the guide fixture with clamping device shown in figure 2 is as follows: If the chest part 17 of the three-point belt 10 is pulled out only with moderate force when put on or when the person buckled in leans forward, the clamping lever 29 according to figure 3 either does not pivot at all or pivots only very little in the anticlockwise direction about the shaft 28, so that the clamping jaws 33 and 34 do not come into contact with the belt portion 19.

At the same time, the gas spring cushion 38 opposes the withdrawal force with a corresponding pre-determined resistance.

When the pull on the belt stops, the clamping lever 29 returns to its initial position, i.e. the long lever arm 32 moves to the right, in figure 2, until the spring 38 is released to a preset spring force. If, on the other hand, the belt is withdrawn with greater force, particularly jerkily, the lever arm 32 pivots further to the left, in figure 2, and the lever arm 31 moves accordingly to the right, as a result of which the belt portion 19 is clamped between the clamping jaws 33 and 34 and is held fast. This happens very quickly so that the safety belt is blocked immediately. When the pull on the belt is released, the spring 38 presses the lever arm 32 back into its initial position, whereby the clamping jaws 33, 34 also release the belt 19. The belt is clamped immediately below the cross member 35, so that the least possible extension of the belt can occur.

Instead of the gas spring cushion 38, a steel compression or tension spring may also be used, and in this case it is particularly advantageous to use a pre-shaped leaf spring which loses its stability of shape when a pre-determined force is reached and therefore suddenly falls off sharply in its spring power. Leaf springs of this kind are also known as click springs in simple toys for children. An important factor is that the spring characteristics should be capable of being set exactly.

Whereas, in the embodiments by way of example in figure 2, the blocking is effected directly by the pulling of the belt 10 over the cross member 35, whilst the spring force determines the response threshold belt tension, a vehicle-sensitive blocking can also be carried out by means of corresponding controlling the belt reel 20 (figure 1), for example by means of a ball or pendulum sensor which is known as such, which means that there is no need to explain it here.

On the other hand, an embodiment (not illustrated) is possible wherein the clamping device is controlled, in vehicle-sensitive manner, directly at the clamping lever. This has the advantage that the belt reel may be constructed for example, as a mere spool with a return spring, i.e. in the simplest of constructions, since there is no need for blocking to take place on or in the reel. The reel does not need to absorb any particular forces and can therefore be constructed from lightweight materials, e.g. plastics.

Such apparatus corresponds largely to the embodiment of figure 2, with regard to its housing and its clamping lever with the clamping jaws but in this case the control is effected by means of a member in which a permanent magnet is combined with an electromagnet. The permanent magnet, the holding force of which is matched to the desired response sensitivity of the clamping device, holds the clamping lever in place in its non-blocking position. If a predetermined belt force is exceeded when the belt is withdrawn, the torque of the twoarmed lever overcomes the holding force of the permanent magnet and the belt is clamped between the clamping jaws and blocked. If the pull on the belt is released the clamping lever urged by the reel spring in the belt reel pivots back in the anticlockwise direction, and the permanent magnet again holds the short lever arm firmly.

Control which is sensitive to acceleration of the vehicle is effected by means of a sensor which may be constructed in known manner. If a pre-determined acceleration value is exceeded, positively or negatively, the sensor closes an electrical switch so that the electromagnet is activated, the holding force of the permanent magnet is overcome and the clamping lever is repelled. There may be connected in parallel with the sensor a switch which is closed by actuating the vehicle brakes and causes the same effect.

The clamping lever 29 according to figure 2 may also be controlled in ways other than those using the magnets shown here, for example by means of a known inertia mass which responds to accelerations of the vehicle.

In the sensor the deflection of a pendulum, ball or the like, dependent on acceleration, closes a circuit resulting in a brief impulse. This impulse is converted by an electronic control in the sensor into a surge of current lasting a few seconds (at least 30 milliseconds) which cuts out automatically. This measure is of essential importance for the action of the magnetic control of the clamping device.

As a rule, the sensor which is sensitive to vehicle acceleration in fact responds substantially earlier than the person who is strapped in, to a retarding of the vehicle, so that the belt is stressed later than when the electromagnet is actuated. If the electromagnet did not maintain the blocking for a certain period, the blocking would occur only as a result of the tension of the belt, thus losing valuable time and enabling a substantial length of safety belt to pass through the fixture.

In a further embodiment similar to that described above the permanent magnet can be replaced by a helical tension spring.

Figures 3 and 4 show an embodiment by way of example with a one-armed clamping lever 50, which is mounted so as to be pivotally movable in a substantially Ushaped housing with a fixing means 25, 26, front wall 51 and side walls 52. The front wall 51 has a window 53 for the passage of the clamping lever 50, and the lower edge of the window 53 is constructed as a projecting beading 49 against which the cross member 35 of the lever 50 can lodge, when moved clockwise, with the safety belt 17, 19 positioned therebetween. Here, too, the cross member 35 has lateral projections 36 with the above mentioned comparatively large radius.

The clamping lever 50 is connected hingedly to a control shoe 54 which is Ushaped in cross-section, and which is guided for parallel movement by hinged arms 55.

On the inside of the front wall 51 of the housing are mounted combined permanent magnet and electromagnetl56 and 57 which, in connection with a plate 58 of a suitable material act in the same way as the relevant parts in the second embodiment described above.

In the release position of the belt according to figure 3, the clamping lever 50 projects with the cross member 35 forwards out of the window 53 so that the portion 19 of the belt can run straight downwards to the belt store (not shown) and the belt is guided only once to the chest belt portion 17. The permanent magnet 56 holds the control shoe 54 firmly in position so that the clamping lever 50 remains in its upper position. If there is a tension force on the belt portion 17 which exceeds the holding force of the permanent magnet 56, the plate 58 becomes detached from the magnet 56, the control shoe 54 pivots back and the clamping lever 50 and hinged arms 55 pivot downwardly. This is done jerkily until the cross member 35, clamping the belt, reaches the lower edge 49 of the window 53, as shown in figure 4. Instead of this safety beltsensitive control, there may also be a vehicle-sensitive control, by replacing the permanent magnet electromagnet combination with a single electromagnet actuated by a sensor, which electromagnet holds the clamping lever 50 in the upper dead centre position until the sensor responds.

WHAT WE CLAIM IS: 1. A safety belt guide fixture for a safety belt having an automatic reeling mechanism, comprising a housing adapted to be mounted to a structural part of a vehicle, a lever pivotably mounted in the housing, said lever including a cross member spaced from and substantially parallel to the pivot axis and defining therebetween an aperture through which the belt passes in use being guided once around the cross member only, from where in the non-clamped position the belt passes without further change of direction to the reeling mechanism in one direction and to the body of an occupant in the other direction, the lever further including a clamping surface by which the belt runs in normal use, the arrangement being such that pivoting of the lever causes the belt to be clamped between the clamping surface and an associated surface, biasing means being provided for resisting such pivoting of the lever.

2. A fixture according to claim I in which the lever is in the form of a frame, said cross member forming one side of the frame, projecting shoulders being provided at each end of the cross member for guiding the belt thereover.

3. A fixture according to claim 2 in which the shoulders extend directly from the surface of the cross member over which the belt runs merging therein to with a considerable radius relative to the belt thickness.

4. A fixture according to claim 3 in which said radius is between five and ten times the thickness of the belt.

5. A fixing according to any of the preceding claims in which the lever is formed as a two-armed lever, the clamping surface being formed on one arm, said biasing means comprising a resilient compression member disclosed between the other arm and the housing.

6. A fixture according to claim 5 in which

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (18)

**WARNING** start of CLMS field may overlap end of DESC **. which responds to accelerations of the vehicle. In the sensor the deflection of a pendulum, ball or the like, dependent on acceleration, closes a circuit resulting in a brief impulse. This impulse is converted by an electronic control in the sensor into a surge of current lasting a few seconds (at least 30 milliseconds) which cuts out automatically. This measure is of essential importance for the action of the magnetic control of the clamping device. As a rule, the sensor which is sensitive to vehicle acceleration in fact responds substantially earlier than the person who is strapped in, to a retarding of the vehicle, so that the belt is stressed later than when the electromagnet is actuated. If the electromagnet did not maintain the blocking for a certain period, the blocking would occur only as a result of the tension of the belt, thus losing valuable time and enabling a substantial length of safety belt to pass through the fixture. In a further embodiment similar to that described above the permanent magnet can be replaced by a helical tension spring. Figures 3 and 4 show an embodiment by way of example with a one-armed clamping lever 50, which is mounted so as to be pivotally movable in a substantially Ushaped housing with a fixing means 25, 26, front wall 51 and side walls 52. The front wall 51 has a window 53 for the passage of the clamping lever 50, and the lower edge of the window 53 is constructed as a projecting beading 49 against which the cross member 35 of the lever 50 can lodge, when moved clockwise, with the safety belt 17, 19 positioned therebetween. Here, too, the cross member 35 has lateral projections 36 with the above mentioned comparatively large radius. The clamping lever 50 is connected hingedly to a control shoe 54 which is Ushaped in cross-section, and which is guided for parallel movement by hinged arms 55. On the inside of the front wall 51 of the housing are mounted combined permanent magnet and electromagnetl56 and 57 which, in connection with a plate 58 of a suitable material act in the same way as the relevant parts in the second embodiment described above. In the release position of the belt according to figure 3, the clamping lever 50 projects with the cross member 35 forwards out of the window 53 so that the portion 19 of the belt can run straight downwards to the belt store (not shown) and the belt is guided only once to the chest belt portion 17. The permanent magnet 56 holds the control shoe 54 firmly in position so that the clamping lever 50 remains in its upper position. If there is a tension force on the belt portion 17 which exceeds the holding force of the permanent magnet 56, the plate 58 becomes detached from the magnet 56, the control shoe 54 pivots back and the clamping lever 50 and hinged arms 55 pivot downwardly. This is done jerkily until the cross member 35, clamping the belt, reaches the lower edge 49 of the window 53, as shown in figure 4. Instead of this safety beltsensitive control, there may also be a vehicle-sensitive control, by replacing the permanent magnet electromagnet combination with a single electromagnet actuated by a sensor, which electromagnet holds the clamping lever 50 in the upper dead centre position until the sensor responds. WHAT WE CLAIM IS:

1. A safety belt guide fixture for a safety belt having an automatic reeling mechanism, comprising a housing adapted to be mounted to a structural part of a vehicle, a lever pivotably mounted in the housing, said lever including a cross member spaced from and substantially parallel to the pivot axis and defining therebetween an aperture through which the belt passes in use being guided once around the cross member only, from where in the non-clamped position the belt passes without further change of direction to the reeling mechanism in one direction and to the body of an occupant in the other direction, the lever further including a clamping surface by which the belt runs in normal use, the arrangement being such that pivoting of the lever causes the belt to be clamped between the clamping surface and an associated surface, biasing means being provided for resisting such pivoting of the lever.

2. A fixture according to claim I in which the lever is in the form of a frame, said cross member forming one side of the frame, projecting shoulders being provided at each end of the cross member for guiding the belt thereover.

3. A fixture according to claim 2 in which the shoulders extend directly from the surface of the cross member over which the belt runs merging therein to with a considerable radius relative to the belt thickness.

4. A fixture according to claim 3 in which said radius is between five and ten times the thickness of the belt.

5. A fixing according to any of the preceding claims in which the lever is formed as a two-armed lever, the clamping surface being formed on one arm, said biasing means comprising a resilient compression member disclosed between the other arm and the housing.

6. A fixture according to claim 5 in which

said compression member comprises a gas spring cushion.

7. A fixture according to claim 6 in which said cushion comprises a block of foam plastics made up of gas-filled cells.

8. A fixture according to any of claims 1 to 4 in which said biasing means comprises a preformed leaf spring which loses its dimensional stability upon reaching a predetermined stress and whose elastic resistance suddenly falls off sharply.

9. A fixture according to any of the preceding claims in which the lever has a bent lever arm carrying the cross member and the clamping surface is disposed between the bend and pivotal axis.

10. A fixture according to claim 9 in which said associated surface is dispoed on the front wall of the housing and the biasing means is disposed between another arm of the lever and a rear wall of the housing.

11. A fixture according to any of claims 1 to 4 and 9 or 10 where dependent on I to 4, in which the biasing means comprises a permanent magnet whose holding power corresponds to the maximum permissible belt tension for there to be no clamping.

12. A fixture according to claim 11 in which the permanent magnet is operatively associated with an electromagnet forming part of an electrical circuit including a vehicle acceleration sensing device.

13. A fixture according to any of claims 1 to 4 and 9 or 10 where dependent on 1 to 4 in which the biasing means comprises a tension spring whose holding power corresponds to the maximum permissible belt tension for there to be no clamping said spring being operatively associated with an electromagnet forming past of an electrical circuit including a vehicle acceleration sensing device.

14. A fixture according to claim 12 or 13 in which the vehicle acceleration sensing device is by means of an electrical control device adapted to generate a current surge of limited duration for said electromagnet upon a predetermined vehicle acceleration, an automatic cut-out being provided for terminating said current.

15. A fixture according to claim 14 in which the current duration is set to be at least 30 milliseconds.

16. A fixture according to any of claims 1 to 4 or 8 to 13 where dependent on 1 to 4 in which the lever comprises a single armedlever extending through an aperture in the housing, the cross member lying outside the housing, the clamping surface being provided on the cross member and the associated surface comprising a lower wall of the aperture, a control shoe in operative association with said biasing means being guided for parallelwise movement within the housing and being pivotably connected to the lever.

17. A fixture according to any of the preceding claims so dimensioned as to fit within the middle window pillar of a vehicle.

18. A safety belt guide fixture substantially as hereinbefore described with reference to the accompanying drawings.