Latch plate and method for producing a latch plate

Abstract

A locking tongue for a seat belt has a deflecting portion for a webbing. The deflecting portion includes a webbing passage and a clamping element. The clamping element is displaceable between a home position in which the webbing is freely movable and a blocking position in which the clamping element is displaced against a wall of the webbing passage so that the webbing is clamped between the clamping element and the wall of the webbing passage. The clamping element includes a clamping surface which in the blocking position clamps the webbing against the wall of the webbing passage. The clamping element is guided along a curved guide path extending in an area of the blocking position substantially perpendicularly to the wall so that in the blocking position the clamping element is moved against the wall substantially perpendicularly with the clamping surface.

Claims

1. A locking tongue (10) for a seat belt comprising an inserting portion (12) adapted to be inserted into a belt buckle and a deflecting portion (14) for a webbing (16), wherein the deflecting portion (14) includes a webbing passage (20) through which the webbing (16) is guided and a clamping element (22) for the webbing (16), the clamping element (22) being displaceable between a home position in which the webbing (16) is freely movable and a blocking position in which the clamping element (22) is displaced against a wall (36) of the webbing passage (20) so that the webbing (16) is clamped between the clamping element (22) and the wall (36) of the webbing passage (20), the clamping element (22) including a clamping surface (24) which in the blocking position clamps the webbing (16) against the wall (36) of the webbing passage (20), wherein the clamping element (22) is guided along a curved guide path (40) extending in an area of the blocking position substantially perpendicularly to the wall (36) so that in the blocking position the clamping element (22) is moved against the wall (36) substantially perpendicularly with the clamping surface (24), wherein an effective height of the clamping surface (24), measured in a longitudinal direction of the webbing (16), is larger than a height of the guide path, and wherein the clamping surface (24) in the blocking position is arranged in parallel to the wall (36) and is in full-surface contact with the latter.

2. The locking tongue according to claim 1, wherein the clamping element (22) takes a circular arc shape, in cross-section, the clamping element (22) having a first end in which a deflecting surface (26) for the webbing (16) is provided and a second, opposite end in which the clamping surface (24) is provided.

3. A method of manufacturing a locking tongue (10) according to claim 1, comprising the following features of: providing the deflecting portion (14), positioning the clamping element (22) on the deflecting portion (4), and partly surrounding the deflecting portion (14) and the clamping element (22) by injection-molding so that the clamping element (22) is fixed to the deflecting portion (14).

4. The locking tongue according to claim 1, wherein at least one guideway (30) is provided along which the clamping element (22) is moved.

5. The locking tongue according to claim 4, wherein projections (28) guided in the guideway (30) are arranged on the clamping element (22).

6. The locking tongue according to claim 1, wherein a spring element (38) is provided for forcing the clamping element (22) into the home position.

7. The locking tongue according to claim 6, wherein the spring element (38) is a leaf spring.

8. The locking tongue according to claim 6, wherein the spring element (38) engages at least one opening (48) on the clamping element (22) to force the clamping element (22) into the home position.

9. The locking tongue according to claim 1, wherein the deflecting portion (14) includes an overmolding (18) which encloses the deflecting portion (14) at least in portions, and in that the clamping element (22) is molded into the overmolding (18) in the home position.

10. The locking tongue according to claim 1, wherein the guide path has a first end that faces toward and is parallel to the wall (36), a height of the first end, measured in the longitudinal direction of the webbing (16), being smaller than the effective height of the clamping surface (24), measured in the longitudinal direction of the webbing (16), a portion of the clamping element (22) being surrounded by the first end.

11. The locking tongue according to claim 1, wherein the deflecting portion (14) includes an overmolding (18) which encloses the deflecting portion (14) at least in portions, and the guide path has a first end that faces toward and is parallel to the wall (36), the first end extending in the longitudinal direction of the webbing (16) from a first side that is bounded by the overmolding (18) to a second side that faces oppositely to the first side, a portion of the clamping element (22) being positioned between the first and second sides of the first end, a height between the first and second sides of the first end, measured in the longitudinal direction of the webbing (16), being smaller than the effective height of the clamping surface (24), measured in the longitudinal direction of the webbing (16).

12. The locking tongue according to claim 1, wherein the deflecting portion (14) includes an overmolding (18) which encloses the deflecting portion (14) at least in portions, the clamping element (22) has a first end in which a deflecting surface (26) for the webbing (16) is provided and a second, opposite end in which the clamping surface (24) is provided, the clamping element (22) having oppositely facing first and second surfaces that extend between the deflecting surface (26) and the clamping surface (24), and the first surface of the clamping element (22) directly contacts at least a portion of the overmolding (18) as the clamping element (22) is displaced between the home and blocking positions.

13. The locking tongue according to claim 1, wherein the clamping element (22) has the clamping surface (24) at a first end, a deflecting surface portion (26) at a second, opposite end, a body that extends between the clamping surface (24) and the deflecting surface portion (26), and oppositely facing first and second surfaces that extend from the clamping surface (24), over the body and to the deflecting surface portion (26), a distance between the first and second surfaces at the clamping surface (24) being larger than a distance between the first and second surfaces at the body and larger than a distance between the first and second surfaces at the deflecting surface portion (26).

14. The locking tongue according to claim 13, wherein the height of the guide path is larger than or equal to the distance between the first and second surfaces at the body and larger than or equal to the distance between the first and second surfaces at the deflecting surface portion (26), the height of the guide path being smaller than the distance between the first and second surfaces at the clamping surface (24).

15. The locking tongue according to claim 13, wherein at least one of the body and the deflecting surface portion (26) of the clamping element (22) are positioned within the guide path while the clamping surface (24) of the clamping element (22) protrudes from the guide path.

16. The locking tongue according to claim 1, wherein the deflecting portion (14) includes an overmolding (18) which encloses the deflecting portion (14) at least in portions, the guide path extends between a first surface of the overmolding (18) and a second surface of the overmolding (18), the second surface of the overmolding (18) facing toward the first surface of the overmolding (18), and a distance between the first and second surfaces of the overmolding (18) is smaller than the effective height of the clamping surface (24).

17. The locking tongue according to claim 1, wherein the deflecting portion (14) includes an overmolding (18) which encloses the deflecting portion (14) at least in portions, the guide path extends between a first surface of the overmolding (18) and a first surface of a retaining land (42) that fixes the clamping element (22) to the deflecting portion (14), the first surface of the retaining land (42) facing toward the first surface of the overmolding (18), and a distance between the first surface of the overmolding (18) and the first surface of the retaining land (42) is smaller than the effective height of the clamping surface (24).

18. The locking tongue according to claim 1, wherein the clamping element (22) has a first end in which a deflecting surface (26) for the webbing (16) is provided and a second, opposite end in which the clamping surface (24) is provided, and a portion of the clamping surface (24) that contacts the webbing (16) in the blocking position is larger than a portion of the deflecting surface (26) that contacts the webbing (16) in at least one of the blocking and home positions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and features will be resulting from the following description in conjunction with the enclosed drawings, in which:

(2) FIG. 1 shows a perspective view of a locking tongue according to the invention,

(3) FIG. 2 shows a sectional view across the locking tongue from FIG. 1,

(4) FIG. 3 shows a perspective partial sectional view across the locking tongue from FIG. 1,

(5) FIG. 4 shows the locking tongue from FIG. 2 with the clamping element being in a blocking position,

(6) FIGS. 5a to 5d show a sectional view of the locking tongue from FIG. 1 in the area of the clamping element during the displacing operation from the home position to the blocking position.

(7) FIGS. 6a to 6c show different method steps for manufacturing the locking tongue from FIGS. 1 to 4,

(8) FIG. 7 illustrates an exploded view of a second embodiment of a locking tongue according to the invention,

(9) FIG. 8 shows a sectional view of the locking tongue from FIG. 7 with the damping element being in the home position,

(10) FIG. 9 shows a partial sectional view of the locking tongue from FIG. 8,

(11) FIG. 10 shows a sectional view of the locking tongue from FIG. 8 with the clamping element being in the blocking position,

(12) FIGS. 11a to 11e illustrate different method steps for manufacturing the locking tongue from FIGS. 7 to 10,

(13) FIG. 12 illustrates a third embodiment of a locking tongue according to the invention,

(14) FIG. 13 illustrates a fourth embodiment of a locking tongue according to the invention,

(15) FIG. 14 shows a partial sectional view of the locking tongue from FIG. 13, and

(16) FIG. 15 shows another partial sectional view of the locking tongue from FIG. 13.

DESCRIPTION

(17) In FIGS. 1 to 4 a locking tongue 10 for a seat belt in a vehicle is illustrated. The locking tongue 10 includes an inserting portion 12 adapted to be inserted into a belt buckle and to be locked there as well as a deflecting portion 14 adapted to be threaded onto webbing 16 and to deflect said webbing 16 (cf. FIGS. 5a to 5d). The deflecting portion 14 includes an overmolding 18 made of plastic which completely encloses the deflecting portion 14.

(18) As is especially evident from FIG. 2, a webbing passage 20 through which the webbing 16 is guided and a clamping element 22 whose function will be explained hereinafter are provided on the deflecting portion 14. The clamping element 22 takes a curved shape, in this embodiment a circular arc shape, in cross-section and includes a clamping surface 24 feeing the webbing passage 20 as well as a deflection surface 26 disposed at the opposite end. On the side of the clamping element 22 are arranged projections 28 by which the clamping element 22 is guided laterally in a guideway 30 provided at the deflecting portion 14. The guideway 30 may be formed by the overmolding 13 and/or by the deflecting portion 14.

(19) The basic functioning of the clamping element 22 will be illustrated hereinafter by way of the FIGS. 5a to 5d.

(20) In a home position shown in FIG. 5a the webbing 16 is guided through the webbing passage 20 and may be displaced in the longitudinal direction L through the webbing passage 20.

(21) Upon buckling the webbing 16 then extends in U-shape through the deflecting portion 14, with the webbing 16 being divided into a first portion 32 and a second portion 34 (FIG. 5b). The first portion 32 is guided around the pelvis area of a vehicle occupant, for example, and the second portion 34 extends starting from the locking tongue 10 around the upper body of the vehicle occupant,

(22) In the buckled state shown in FIG. 5b the webbing 16 may be moved freely through the deflecting portion 14 so that an adaptation in length of the two portions 32, 34 is possible in connection with a belt retractor. The webbing 16 thus may be adjusted so that both portions 32. 34 are in contact with the vehicle occupant. This prevents the vehicle occupant reliably from moving forward when the seat belt blocks.

(23) In a case of restraint the belt retractor is blocked. When the vehicle occupant then moves forward out of position, a tensile force Z acts on each of the two portions 32, 34 (cf. FIG. 5c). The webbing 16 is pulled close to the clamping element 22 by the tensile forces Z. Subsequently the clamping element 22 is displaced by the webbing 16 along the guideways 30 and is moved into the webbing passage 20.

(24) The clamping element 22 is inserted into the webbing passage 20 until it abuts against an opposite well 36 and the webbing is clamped between the wall 36 and the clamping surface 24 of the clamping element 22.

(25) In this blocking position of the clamping element 22 the webbing 16 is fixed to the locking tongue 10 (FIG. 5d). Shortening of the first portion 32 and consequently constricting the first portion 32 laid around the pelvis by a forward movement of the upper body and the resulting lengthening of the second portion 34 is thus reliably excluded.

(26) Since with an increasing tensile force Z acting on the webbing 16 also the force by which the clamping element 22 is pressed against the wall 36 increases, reliable fixation of the webbing 16 is ensured even with high tensile forces Z acting on the webbing 16.

(27) As is evident from the FIGS. 2 and 4, the clamping element 22 is movably guided on a curved guide path 40. The clamping surface 24 is arranged so that it is moved in the blocking position shown in FIG. 4 substantially perpendicularly against the wall 36 of the webbing passage 20 and in the blocking position is adjacent to the wall 36 substantially in parallel thereto.

(28) In this way the contact area between the webbing 16 and the clamping surface 24 is increased so that a higher retaining force can be provided for the webbing 16.

(29) The curved shape of the clamping element 22 causes the tensile force Z substantially acting in the direction of the webbing 16 to be deflected so that the clamping element is forced substantially perpendicularly against the wall 36.

(30) Since the clamping element 22 is guided substantially perpendicularly against the wall 36 by the clamping surface 24, the clamping element 22 is not pressed into the webbing passage 20. Moreover, the clamping element 22 cannot be drawn into the webbing passage 20 by the webbing 16, either. Hence the clamping element 22 cannot get jammed or wedged within the webbing passage 20.

(31) Upon completion of the case of restraint and weakening of the tensile force Z acting on the webbing 16 and the deflecting surface 26 of the clamping element 22, the clamping element 22 may be easily returned from the blocking position to the borne position. For this purpose, the webbing need not be moved in the webbing passage 20.

(32) In particular, it is also possible to return the clamping element 22 to the home position, when tensile force Z continues acting on the second portion 34, as the damping element 22 is not retained in the blocking position by the webbing 16. It is merely necessary that there is no force acting on the deflecting surface 26.

(33) It is thus possible to return the clamping element from the blocking position to the home position independently of the tensile force Z acting in the case of restraint in a simple manner and by the same force. In particular no jammed or wedged clamping element 22 has to be released.

(34) In the embodiment illustrated in FIGS. 1 to 4 the clamping element 22 is molded into the overmolding 18 of the deflecting portion 14 and in this way is retained in the home position. When a defined tensile force Z is exceeded, said fixation is released and the clamping element 22 may be displaced into the blocking position (FIG. 4).

(35) A method of manufacturing said locking tongue 10 is illustrated in FIGS. 6a to 6c. After providing the base body of the inserting portion 12 and the deflecting portion 14 (FIG. 6a), the clamping element 22 is positioned at the deflecting portion 14 in the home position (FIG. 6b). Subsequently the deflecting portion 14 is surrounded by injection-molding with the webbing passage 20 being kept free (FIG. 6c). In the home position the clamping surface 24 of the clamping element preferably is part of the webbing passage 20.

(36) A second embodiment of a locking tongue according to the invention is shown in FIGS. 7 to 10.

(37) The structure of said looking tongue 10 substantially corresponds to the locking tongue 10 illustrated in FIGS. 1 to 4. Other than in that embodiment, the clamping element 22 is freely movable in the guideway 30 and is not molded in the overmolding, however. In addition, a spring element 38 is provided which in this case is constituted by a leaf spring and Includes two resilient lands 39. Said spring element 38 is partly molded in the overmolding 18 and is supported by the deflecting portion 14. The spring element 38 engages in two openings 48 on the clamping element 22 and acts upon the latter in the home position (cf. FIGS. 8 and 9). Moreover, a retaining land 42 is arranged to fix the clamping element 22 to the deflecting portion 14.

(38) When tensile force Z acts on the webbing 16, the clamping element 22 is moved against the spring force of the spring element 38 into the blocking position. As soon as the tensile force Z acting on the webbing 16 weakens, the spring element 38 withdraws the clamping element 22 into the home position. Thus a reversible use of the looking tongue 10 is possible.

(39) A method of manufacturing said locking tongue 10 is illustrated in FIGS. 11a to 11e.

(40) After providing the base body (FIG. 11a) the spring element 38 is Inserted Into a seat 44 (FIG. 11b) and the deflecting portion is subsequently surrounded by injection-molding (FIG. 11c), with the webbing passage 20 and a guide passage 46 for the clamping element 22 being kept free. In addition, a passage for the retaining land 42 is kept free.

(41) Subsequently the clamping element 22 is inserted into the guide passage 46. The guide passage 46 is configured so that the clamping element 22 can also be inserted with a wide damping surface 24 and thus has play in the guide passage 46 in this condition. Said play is required for inserting the clamping element 22 past the spring element 38 into the guide passage 46. Finally the retaining land 42 is laterally inserted, thus causing the clamping element 22 to be pushed with the openings 48 onto the lands 39 of the spring element 38 and the guide passage 46 to be narrowed so that the clamping element 22 is guided free from play.

(42) The embodiment shown in FIG. 12 differs from the embodiment shown in FIGS. 7 to 10 merely by the spring element 38 being a torsion spring or a yoke spring, respectively.

(43) FIGS. 13 to 15 illustrate a third embodiment of a locking tongue 10 according to the invention. The latter substantially corresponds to the locking tongue 10 shown in FIGS. 1 to 4. The end of the clamping element 22 on the side of the clamping surface is hook-shaped in cross-section (cf. FIG. 13), however, so that a wider clamping surface 24 is formed.

(44) Irrespective of this embodiment, the clamping element 22 may also be fixed in the home position or forced into the home position, resp., in a different way. For example, it is possible to provide bolts or other elements having a predetermined breaking point. Instead of the spring elements 38, for example, also rubber elements or other resilient elements may be used which act on the clamping element 22 in the home position and, respectively, return the latter to the home position upon completion of the event of restraint.