GB1589059A - Buckle for safety belts and seat belts - Google Patents

Description

(54) BUCKLE FOR SAFETY BELTS AND SEAT BELTS (71) We, SECURON A.G., a Swiss Body Corporate, of Schanzenegg Strasse 1, CII 8002, Zurich, Switzerland, 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: - This invention relates to the buckles of safety belts and seat belts, especially those used in road vehicles and aircraft.

Such buckles generally include a spring latch which serves to hold a spigot or shank of a safety belt or seat belt in a releasable manner. Release of the spigot or shank from the buckle is normally effected by the wearer of the belt through the application of thumb or finger pressure to a springloaded button or lever which moves a latch member of the spring-latch out of its latching position against the action of the spring of a spring latch.

It is, however, generally known and accepted that the latch-member of the springlatch can also move out of its latching position under inertia forces applied to the buckle - for example, as a result of a sharp knock on the buckle. This is naturally undesirable, for the whole purpose of a safety or seat belt is to hold the wearer securely until such time as the spigot or shank of the safety belt is deliberately released.

The aim of the present invention is to prevent such an accidental and unwanted movement of the latch member, and with this in view the invention is directed to a buckle which includes a counter-balance weight so arranged that, if an inertia force acts on the spring-latch so as to tend to move a latch member thereof out of its latching position, the inertia force also causes the counter-balance weight to oppose the force acting on the latch member and to nullify its effect.

An example of a buckle in accordance with the invention is shown in the accompanying drawing, in which: Figure 1 is a vertical section through the buckle; and Figure 2 is a plan view of a counterbalance weight included in the buckle.

The buckle shown in Figure 1 comprises a hollow casing 10 made of metal or synthetic plastics material having an opening 12 at one end through which passes a stem 14, the far end of which (not shown) is adapted to be fastened to a rigid part of a road vehicle - for example, to the floor of the vehicle between the driver's seat and the front passenger seat.

The part of the stem 14 received by the casing 10 serves to support a socket member 16 adapted to receive a spigot or shank 18 attached to a safety belt or seat belt, the spigot or shank 18 (of which only a small portion is shown in Figure 1) being releasably insertable into the socket member 16 through a mouth 20 in the other end of the casing 10. In the particular construction shown in Figure 1, the stem 14 supports the socket member via a lug 22 attached to the stem and a pin or other such member 24 which extends through a root portion of the socket member 16 and through a hole in the lug 22.

In order that the spigot or shank 18 may be held releasably in the socket member 16, a latch member 26, being part of a spring-latch, is mounted for sliding movement transversely of the longitudinal direction of the socket member 16. Thus, as the spigot or shank 18 passes through the mouth 20 of the casing 10, its nose portion strikes an inclined surface 28 on the latch member and forces it downwards so that the nose portion of the spigot or shank can pass against withdrawal from the socket member by virtue of a shoulder 30 on the latch member 26 engaging a corresponding shoulder (not shown) on the spigot or shank 18.In its "latched" position, where the spigot or shank 18 is held against withdrawal from the socket member 16 by the latch member 26, the nose of the spigot or shank is in engagement with a sliding abutment 32 and compresses a helical spring 40 arranged to the rear of this abutment. This means that the spring 40 is compressed when the spigot or shank 18 is latched and therefore acts to urge the spigot or shank out of the socket member 16.

In order that the latch member 26 may hold the spigot or shank 18 securely in the latched position, a leaf spring 42 of the spring-latch is arranged to bear against an undersurface 44 of the latch member 26, a root portion 46 of the leaf spring 42 being rigidly held by the pin 24.

Release of the spigot or shank 18 from the socket member 16 is normally effected by sliding a spring-loaded button 48 to the right as shown by the arrow 50 so that a cam member 52 carried by the button 48 makes contact with a surface 54 on the latch member 26 and forces the latter downwardly against the action of the leaf spring 42. Downward movement of the latch member 26 in this way has the result of disengaging its shoulder 30 from the corresponding shoulder on the spigot or shank 18, with the result that the compressed helical spring 40 acts through the sliding abutment 38 to push the spigot or shank 18 out of the socket member 16. As will be seen, the spring which acts on the button 48 comprises a helical spring 56 surrounding an elongate pin 58, the front edge 60 of the cam member 52 being adapted to compress the spring 56 as the button 48 is moved to the right.It thus follows that the spring 56 will therefore push the button 48 back to its original position once the button is released.

The construction described above is designed to enable a wearer of a seat belt or safety belt to keep himself or herself secured by the belt until such time as he or she deliberately operates the button 48 by thumb or finger pressure to release the latch member 26. It has been found, however, that the latch member in conventional buckles can sometimes move out of its latching position under inertia forces applied to the buckle -- for example, as a result of a sharp knock on the buckle. This is clearly undesirable as release of the spring-latch in this way defeats the whole purpose for which the safety belt or seat belt is provided, namely, to hold the wearer securely until such time as the spring-latch is released deliberately.

In order to prevent such accidental and unwanted movement of the latch member 26 in the buckle shown in the accompanying drawing, the casing 10 contains a counter-balance weight 62 which lies immediately beneath the leaf spring 42 with an end portion lying below the latch member 26. In the particular buckle shown in the accompanying drawing, the counterbalance weight 62 takes the form of a metal strip bent to a shallow V form and having a narrower neck portion 64, as shown in Figure 2. It is however to be understood that the shape and form of the counterbalance weight can be widely varied according to the construction of the buckle.

By providing the counter-balance weight 62 in the buckle casing 10, any inertia force which acts on the latch member 26 in such a way as to tend to move it out of its latching position will also cause the counterbalance weight 62 to oppose the force acting on the latch member and to nullify its effect. To enable the counter-balance weight 62 to act in this way, it is permitted to "float" within the buckle casing 10 between an adjacent wall of the casing and the leaf spring 62.

WHAT WE CLAIM IS: - 1. A buckle for safety belts and seat belts, especially those used in road vehicles and aircraft, comprising a spring-latch which serves to hold a spigot or shank of a safety belt or seat belt in a releasable manner, and a counter-balance weight so arranged that, if an inertia force acts on a latch member of the spring-latch so as to tend to move it out of its latching position, the inertia force also causes the counterbalance weight to oppose the force acting on the latch member and to nullify its effect.

2. A buckle according to claim 1, in which a leaf spring of the spring-latch is arranged to bear against a surface of the latch member, the counter-balance weight being arranged for floating movement immediately beneath the leaf spring.

3. A buckle according to claim 1 or claim 2, in which the counter-balance weight takes the form of a metal strip.

4. A buckle according to claim 3, in which the metal strip forming the counterbalance weight has a shallow V-form and is provided with a narrower neck portion at that part adjacent the said latch member.

5. A buckle according to claim 2 or any claim appendant thereto, in which the counter-balance weight is permitted to float within a buckle casing between an adjacent wall of the casing and the said leaf spring.

6. A buckle for safety belts and seat belts substantially as described herein with reference to the accompanying drawings.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. therefore acts to urge the spigot or shank out of the socket member 16. In order that the latch member 26 may hold the spigot or shank 18 securely in the latched position, a leaf spring 42 of the spring-latch is arranged to bear against an undersurface 44 of the latch member 26, a root portion 46 of the leaf spring 42 being rigidly held by the pin 24. Release of the spigot or shank 18 from the socket member 16 is normally effected by sliding a spring-loaded button 48 to the right as shown by the arrow 50 so that a cam member 52 carried by the button 48 makes contact with a surface 54 on the latch member 26 and forces the latter downwardly against the action of the leaf spring 42. Downward movement of the latch member 26 in this way has the result of disengaging its shoulder 30 from the corresponding shoulder on the spigot or shank 18, with the result that the compressed helical spring 40 acts through the sliding abutment 38 to push the spigot or shank 18 out of the socket member 16. As will be seen, the spring which acts on the button 48 comprises a helical spring 56 surrounding an elongate pin 58, the front edge 60 of the cam member 52 being adapted to compress the spring 56 as the button 48 is moved to the right.It thus follows that the spring 56 will therefore push the button 48 back to its original position once the button is released. The construction described above is designed to enable a wearer of a seat belt or safety belt to keep himself or herself secured by the belt until such time as he or she deliberately operates the button 48 by thumb or finger pressure to release the latch member 26. It has been found, however, that the latch member in conventional buckles can sometimes move out of its latching position under inertia forces applied to the buckle -- for example, as a result of a sharp knock on the buckle. This is clearly undesirable as release of the spring-latch in this way defeats the whole purpose for which the safety belt or seat belt is provided, namely, to hold the wearer securely until such time as the spring-latch is released deliberately. In order to prevent such accidental and unwanted movement of the latch member 26 in the buckle shown in the accompanying drawing, the casing 10 contains a counter-balance weight 62 which lies immediately beneath the leaf spring 42 with an end portion lying below the latch member 26. In the particular buckle shown in the accompanying drawing, the counterbalance weight 62 takes the form of a metal strip bent to a shallow V form and having a narrower neck portion 64, as shown in Figure 2. It is however to be understood that the shape and form of the counterbalance weight can be widely varied according to the construction of the buckle. By providing the counter-balance weight 62 in the buckle casing 10, any inertia force which acts on the latch member 26 in such a way as to tend to move it out of its latching position will also cause the counterbalance weight 62 to oppose the force acting on the latch member and to nullify its effect. To enable the counter-balance weight 62 to act in this way, it is permitted to "float" within the buckle casing 10 between an adjacent wall of the casing and the leaf spring 62. WHAT WE CLAIM IS: -

1. A buckle for safety belts and seat belts, especially those used in road vehicles and aircraft, comprising a spring-latch which serves to hold a spigot or shank of a safety belt or seat belt in a releasable manner, and a counter-balance weight so arranged that, if an inertia force acts on a latch member of the spring-latch so as to tend to move it out of its latching position, the inertia force also causes the counterbalance weight to oppose the force acting on the latch member and to nullify its effect.

2. A buckle according to claim 1, in which a leaf spring of the spring-latch is arranged to bear against a surface of the latch member, the counter-balance weight being arranged for floating movement immediately beneath the leaf spring.

3. A buckle according to claim 1 or claim 2, in which the counter-balance weight takes the form of a metal strip.

4. A buckle according to claim 3, in which the metal strip forming the counterbalance weight has a shallow V-form and is provided with a narrower neck portion at that part adjacent the said latch member.

5. A buckle according to claim 2 or any claim appendant thereto, in which the counter-balance weight is permitted to float within a buckle casing between an adjacent wall of the casing and the said leaf spring.

6. A buckle for safety belts and seat belts substantially as described herein with reference to the accompanying drawings.