GB1583116A

GB1583116A - Locking device particularly for safety belts

Info

Publication number: GB1583116A
Application number: GB15357/78A
Authority: GB
Original assignee: BUIRETTE A
Current assignee: BUIRETTE A
Priority date: 1977-04-22
Filing date: 1978-04-19
Publication date: 1981-01-21
Also published as: JPS54323A; IT1094097B; IT7822486A0; FR2387663B3; DE2817266A1; FR2387663A1

Description

(54) A LOCKING DEVICE, PARTICULARLY FOR SAFETY BELTS (71) We, EUGENE, MATHIEU LAPORTE of 14 rue Victor Hugo, La Rochelle (Seine Maritime) France and ANNIE BUIRE?TE 49 rue de la Resistance Chaville (Hauts de Seine) France, both of French nationality, 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 present invention relates to a locking device, especially for safety belts, of the type comprising a piston sliding within a cylinder under the action of spring means, which piston controls the opening of two pivotally mounted jaws.

The object of the present invention is to apply the device of the invention to motor-car seat belts and to allow the user to be released automatically when he undergoes one or more successive jolts in the course of an accident.

A further object of the present invention is to provide a locking-device which is simple in its conception and is inexpensive to manufacture.

Finally, the present invention also provides a locking-device which the user does not require to manipulate in the case of a jolt since the device releases the seat beltautomatically after a certain time.

According to the present invention there is provided a locking device, especially for safety belts, comprising a delayed action automatic control including a piston slidable within a cylinder under the action of spring means and controlling the opening of two pivotally mounted jaws for holding an end member, and annular sealing means located in a lateral wall of a head of said piston so as to ensure a tight sliding contact between the piston head and the cylinder wall, transfer means being provided to permit the passage of fluid through the piston head towards a piston chamber dependent on the position of the piston; and resilient control means serving to control the opening of the jaws and release of said end member.

By means of such a locking device the belt may be released automatically without the intervention of the user on the occasion of a jolt caused by an accident.

According to a further characteristic of the invention, the transfer means for the passage of the fluid through the piston head is in the form of bores or ports arranged in the periphery of the piston head and interconnected by a circular groove, a radial flow channel being also provided which is located on the outer face of the piston head in contact with a sealing ring and is intended to calibrate the flow of the fluid.

A locking device thus constructed enables the seat-belt to be automatically released after a certain time which is governed by the dimensions of the radial flow channel.

According to a further characteristic of the invention the resilient means comprise a leaf-spring in two parts, one of which is integral with the jaws whilst the other is integral with the control plate controlling the opening of the jaws.

Finally, according to a further characteristic of the invention the part integral with the control plate is of U-profile, the limbs of said U each forming an acute angle and being in contact with the outwardly directed limbs of the part which is integral with the jaws, so that, when pressure is applied to the plate, the two parts slide one upon the other and cause the jaws to open. This device enables the safety belt to be released manually, for example after the user has completed his journey.

An embodiment of the present invention will now be described with reference to an embodiment of a locking device, especially for safety belts, which is given by way of example of a non-limitative character and is illustrated in the accompanying drawings in which: Fig. 1 is a sectional view in plan of a locking device according to the present invention.

Fig. 2 is a front elevation view of the device of Fig. 1 through the line A-A of Fig.

1; Fig. 3 is a sectional side elevation of the device through the line E-E, Fig. 1; Fig. 4 is a sectional side elevation through the device on the line B-B Fig. 1 Fig, 5 is a side elevation on the line C-C, Fig. 1; Fig. 6 is a side elevation on the line F-F, Fig. 1; Fig. 7 is a side elevation on the line D-D, Fig. 1; Referring now to Fig. 1, the device comprises a casing enclosing a cylinder 1 filled with a fluid such as a non-freezing liquid, in which the piston rod 2 moves, the piston 4 being compressed by a spring 3. The piston rod 2 comprises two articulated arms 6 held open by a coil spring 7 and terminating in an inclined ramp 8. The jaws 9 for engaging the belt are pivotally mounted at their centre upon an axis 10. The jaws 9 are firmly held by a coil spring 11.

The casing also contains an external control 12 to enable the jaws 9 to be opened, thus releasing the belt.

The jaws carry nipples 13 for the purpose of ensuring opening of the jaws after a jolt.

Thus after a jolt resulting from an accident, the belt exerts a tension and the locking portion 14 of the belt places the entire device under a pulling effect. The piston 4 then compresses the spring 3 and the liquid passes into the forward part of the cylinder.

The arms 6 of the piston rod 2 pass beneath the nipples 13 of the jaws and open again.

When the jolt ceases, the belt is relaxed and the device, now no longer under tension, allows the piston 4 to return slowly under the action of the spring 3, whereupon the fluid returns to the rear chamber of the cylinder compressing the sealing ring 5 on the piston head 4.

When the piston 4 reaches the end of its stroke, the cams 8 on the arms 6 of the rod 2 epgage with the nipples 13 of the jaw 9.

The jaws 9 pass over the ramp 8. The pivoting of the jaws 9 on their axis 10 tends to open the jaws. The extremity 14 of the belt is released and is ejected by the spring 16.

At the end of the stroke of the piston 4, the jaws 9 return, to their original position and, manual locking and release of the seat-belt are carried out normally. At the end of the cylinder a screw stop 21 is provided for topping the cylinder up with fluid, especially liquid.

The device is housed in a casing comprising two shells 18, 19 clamped together by screws 20. The tightness of the piston within the cylinder is ensured by an annular packing 15.

positioned in the outer wall of the piston head 4.

Thus, when a jplt occurs, the tension.

imparted to the belt causes the spring 3 to be compressed. The fluid passes to the forward part of the cylinder 1 by way of the ports provided in the head of the piston 4. The fluid rasies the sealing ring 5 which slides a short distance on its retaining screw.

When the jolt ceases, the spring 3 is relaxed and pushes the head of the piston 4. The compressed oil in the forward part of the cylinder 1 applies pressure on the sealing ring 5 which is ground to fit the head of the piston 4. The bores located on the piston head 4 communicate with each other by way of a circular groove which is concentric with the piston 4 and is perpendicular to the bores in the piston head.

A fine-bore duct 22 is also provided which is at a right angle to the piston. The calibration of the duct 22 determines the delaytime which is approximately 10 seconds, but can be increased by a few seconds by restricting the size of the duct. The duct 22 thus provides the organ for transfer of the fluid towards the rear part of the cylinder when the device is no longer under tension resulting from the jolt.

Referring to Fig. 2, the device 1 contains an aperture through which the part 14 of the seat-belt is inserted for locking. The locking device is enclosed in a casing comprising two shells 18, 19.

A small control plate mounted on an axis 12 is provided on the plane face of the shell 19, whereby the part 14 of the seat-belt is disengaged by opening of the jaws 9.

Referring to Fig. 3, the control plate is connected to the jaws 9 by a leaf-spring comprising two parts. One part is integral with the control plate and is of U-profile, each of the limbs thereof forming an acute angle. The limbs of the first part are in contact with the limbs of the second part which are integral with the jaws 9 and are directed outwards. Thus, when pressure is applied.

to the control plate, the two parts slide one against the other and force the jaws 9. apart.

In the case of Fig. 4 the two shells 18, 19.

are clamped together by screws 20, thus form ing a casing for the device.

As can be seen in Fig. 5, the jaws 9 are mounted on the cylinder 1 so that they are.

pivotable about an axis 10.

Fig. 6 shows the piston head 4 with ports disposed parallel to the piston rod 2, said ports being interconnected by a circular groove. The ports are grouped around the, periphery of the piston head 4. A calibrated flow channel or duct 22 is also provided.

which is disposed radially but at right angles to the ports and is concentric with the piston 4.

Referring to Fig. 7 the piston rod 2 is secured to a flexible anchor piece on the vehicle floor. This figure also shows the jaws.

9 pivotally mounted, on the cylinder 1 and the arms 6 of the piston rod 2 which pass beneath the nipples 13.

It will be clear that. the invention is not limited. to the embodiment hereinbefore described and illustrated but that, from consideration of this embodiment, it is possible to envisage alternative forms and methods of execution without thereby de parting from the scope of the invention as defined in the appended claims.

WHAT WE CLAIM IS: 1. A locking device, especially for safety belts, comprising a delayed-action automatic control including a piston slidable within a cylinder under the action of spring means and controlling the opening of two pivotally mounted jaws for holding an end member, and annular sealing means located in a lateral wall of a head of said piston so as to ensure a tight sliding contact between the piston head and the cylinder wall, transfer means being provided to permit the passage of fluid through the piston head towards a piston chamber dependent on the position of the piston; and resilient control means serving to control the opening of the jaws and release of said end member.

2. A locking device according to claim 1, wherein the transfer means for the passage of the fluid through the piston head is in the form of bores arranged in the periphery of the piston head and interconnected by a circular groove, a radial duct also being provided which is located on the outer face of the piston head in contact with a sealing ring and serves to calibrate the flow of the fluid.

3. A locking device according to claim 2 wherein the circular groove is concentric with the piston and is transverse to the bores located in the piston head.

4. A locking device according to claim 2 wherein the radial duct for the fluid is disposed transversely to the axis of the piston.

5. A locking device according to any one of the preceding claims, wherein the resilient means is in the form of a leaf-spring comprising two parts, one of which parts is integral with the jaws whilst the other part is integral with a control plate for opening the jaws.

6. A locking device according to claim 5, wherein the part of the leaf spring which is integral with the control plate is of Uprofile the limbs of said U each forming an acute angle and being in contact with the outwardly directed limbs of the part of the leaf spring which is integral with the jaws, so that, when the pressure is applied to the plate, the two parts slide one upon the other and cause the jaws to open.

7. A locking device according to any one of preceding claims wherein the control plate is pivotally mounted on an axis integral with the casing of the device.

8. A locking device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. parting from the scope of the invention as defined in the appended claims. WHAT WE CLAIM IS:

1. A locking device, especially for safety belts, comprising a delayed-action automatic control including a piston slidable within a cylinder under the action of spring means and controlling the opening of two pivotally mounted jaws for holding an end member, and annular sealing means located in a lateral wall of a head of said piston so as to ensure a tight sliding contact between the piston head and the cylinder wall, transfer means being provided to permit the passage of fluid through the piston head towards a piston chamber dependent on the position of the piston; and resilient control means serving to control the opening of the jaws and release of said end member.