Force transmission element for a device for belt tensioning and a device for belt tensioning with such a force transmission element

Abstract

A force transfer element for an apparatus for belt tightening is provided, wherein the force transfer element is a rod-shaped body that is essentially structured over its total length and/or is formed from at least a first and a second part.

Claims

1. A force transfer element for an apparatus for belt tightening, wherein the force transfer element: is a rod-shaped body formed from a plastic, which is structured over its total length, wherein the rod-shaped body includes axial ribs extending in an axial direction of the rod-shaped body and transverse ribs extending transversely to the axial direction and interconnecting the axial ribs; and is formed from at least a first part and a second part, wherein the first part and the second part each include a connecting surface that extends transversely to the axial direction or is inclined at a predetermined angle to the axial direction, and wherein the connecting surfaces of the first part and the second part have matingly engaged connecting portions, the connecting portions including at least one connecting element and at least one connecting recess in which the connecting element is engaged, wherein the connecting element and the connecting recess are configured such that undercuts of the connecting recess retain the connecting element in the connecting recess.

2. The force transfer element according to claim 1, wherein the axial ribs are arranged rotationally symmetrically and are formed in a casing wall of the rod-shaped body.

3. The force transfer element according to claim 1, wherein the first part is formed from a plastic that is different from a plastic from which the second part is formed.

4. The force transfer element according to claim 1, wherein the rod-shaped body is made from a plastic by an extrusion or injection molding process.

5. The force transfer element according to claim 1, wherein the rod-shaped body includes an end face that forms a force transfer surface and has a predetermined rigidity in the axial direction, or includes a casing wall and the casing wall has at least in one force transfer region a force transfer surface, which is elastically or plastically deformable and/or has corresponding actuating recesses, which extend approximately transversely to the axial direction of the rod-shaped body.

6. An apparatus for belt tightening with the force transfer element according to claim 1, comprising: a belt retractor, which is displaceable with an actuating element in a rotational movement such that a seatbelt is retracted or tightened, wherein the actuating element is actuatable by the force transfer element.

7. The apparatus according to claim 6, wherein that the force transfer element has a continuous end wall, which can be loaded by gas pressure and/or spring force, wherein a different end wall is structured or formed continuously.

8. The apparatus according to claim 6, wherein the actuating element of the belt retractor is part of a rotatably supported drive wheel or gear wheel coupled or coupleable to an axis of a belt retractor, and wherein the force transfer element contacts the actuating element in a force transfer region such that the belt retractor is displaceable in a rotational movement such that the seatbelt is retractable and tightenable.

9. A method of manufacturing a force transfer element according to claim 1, wherein the force transfer element is manufactured by a single-component or multi-component injection molding process or by means of an extrusion process.

10. A force transfer element for an apparatus for belt tightening, wherein the force transfer element is formed from at least a first part and a second part, wherein the first part and the second part each include a connecting surface that extends transversely to an axial direction of the force transfer element or is inclined at a predetermined angle to the axial direction, and wherein the connecting surfaces of the first part and the second part have matingly engaged connecting portions, the connecting portions including at least one connecting element projection and at least one connecting recess in which the connecting element projection is engaged, wherein the connecting element projection and the connecting recess are configured such that undercuts of the connecting recess retain the connecting element projection in the connecting recess.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described using exemplary embodiments shown in the figures. The figures show:

(2) FIGS. 1A to 1C, schematic illustrations of a belt tightener known from the prior art,

(3) FIGS. 2A and 2B, a further schematic illustration of a belt tightener known from the prior art,

(4) FIGS. 3A to 3C, a further schematic illustration of a belt tightener known from the prior art,

(5) FIG. 4, a perspective illustration of a further belt tightener known from the prior art,

(6) FIG. 5, a laterally sectioned illustration of a further belt tightener known from the prior art,

(7) FIG. 6, a perspective illustration of a first embodiment of a rod-shaped force transfer element for a belt tightener according to the invention,

(8) FIG. 7, a lateral view of the force transfer element from FIG. 6,

(9) FIG. 8, a front view of the rod-shaped force transfer element with two tool sliders shown schematically,

(10) FIG. 9, a schematic, laterally sectioned illustration of a further embodiment of the rod-shaped force transfer element, and

(11) FIG. 10, a further laterally sectioned illustration of an embodiment of the rod-shaped force transfer element.

DETAILED DESCRIPTION

(12) A force transfer element 1 according to the invention for an apparatus for belt tightening 2 is essentially cylindrical and extends in an axial direction 3.

(13) The force transfer element 1 comprises two end walls as well as a casing wall connecting the two end walls (FIGS. 6 to 10).

(14) One of the two end walls 4, 5 can be loaded by means of gas pressure and/or spring force of a belt tightener 2. This end wall 4 is preferably configured as a continuous, circular, disk-shaped surface, which does not have any recesses and forms a force loading wall.

(15) According to a first embodiment, the total casing wall 6 is enclosed in continuous axial ribs 7 (ridges) extending in the axial or longitudinal direction 3 of the rod-shaped force transfer element 1.

(16) The axial ribs 7 are preferably arranged at a 90° angle or perpendicular to one another.

(17) The longitudinally extending axial ribs 7 can also be discontinuous and thus have grooves (not shown).

(18) Transverse ribs 8 (ridges) extending transversely or orthogonally to the axial direction 3 are further provided, which connect the axial ribs 7 extending in the axial direction 3 to one another. The transverse ribs 8 are preferably arranged equidistant to one another in the longitudinal direction.

(19) According to this exemplary embodiment, four main axial ribs 9 are arranged cross-sectionally in a cross shape, wherein a respective secondary axial rib 9 is arranged at a right angle to each of the main axial ribs 9.

(20) The corresponding ribs 7, 8, 9, 10 (ridges) extending in the axial direction 3 and transverse to the axial direction 3 in a rod-shaped force transfer element 1 or body according to this exemplary embodiment are formed in an injection molding process by means of corresponding tool sliders (FIG. 8).

(21) The end wall 5, which cannot be loaded by means of gas pressure and/or spring force, can also have recesses 11 that are configured correspondingly to the axial ribs 7 due to the manufacturing process. The recesses 11 are also arranged at right angles to one another.

(22) The end wall 5 or the casing wall 6 form either a force transfer wall 11 [sic], depending on whether the force is transferred via the end wall 5 or the casing wall 6.

(23) Such a rod-shaped body transfers its translatory movement to a rotatably supported drive wheel of a belt retractor or an apparatus for belt retraction 2 or to a gearwheel of a belt retractor, so that these are displaced in a rotational movement.

(24) This can preferably be accomplished by elastic but also by plastic deformation of the force transfer wall 12, which is configured as the casing wall 6, of the rod-shaped body and the force transfer element 1, respectively.

(25) In addition and/or alternatively, corresponding recesses, in particular actuating recesses (not shown), extending in the radial direction and approximately corresponding to the respective teeth of the gear-like wheel can be provided. These actuating recesses are formed at least partially or completely radially circumferentially in the casing wall 6 and extend orthogonally to the axial direction 3 and are arranged equidistant to one another in order to actuate a corresponding gearwheel.

(26) According to an alternative embodiment, the rod-shaped body or force transfer element 1 is configured in two parts (FIGS. 9 and 10).

(27) Here, it can be provided that a first and a second part 13, 14 of the rod-shaped body 1 are made of one and the same or of two different plastics.

(28) The first and second parts 13, 14 each have a first and a second connecting surface 15, 16 in a front-facing section.

(29) According to an exemplary embodiment, the connecting surface 15 extends transversely or orthogonally to the axial direction 3 of the rod-shaped body 1 (FIG. 9). In the region of the connecting surface of the first rod-shaped body, an approximately mushroom-shaped connecting element 17 is integrally formed.

(30) The second part 14 of the rod-shaped body 1 has a connecting recess 18 formed correspondingly to the connecting element 17 of the first part 13 of the rod-shaped body 1.

(31) Preferably, the first and second parts 13, 14 are manufactured in a single injection molding process together with the connecting element 17 and the connecting recess 18.

(32) Both parts can be made of the same plastic. Alternatively, such a force transfer element can also be manufactured in a 2-component injection molding process from two different plastics.

(33) Alternatively, initially the first and subsequently the second part of the rod-shaped body 1 can also be manufactured by means of an extrusion process.

(34) A further embodiment of a rod-shaped body formed from a first and a second part is shown in FIG. 10.

(35) The connecting surfaces 15, 16 of the first and the second parts 13, 14 are inclined opposite to the axial and longitudinal direction 3 of the force transfer element 1 (rod-shaped body). Preferably, the first and second parts 13, 14 of the rod-shaped body 1 have a plurality of connecting elements 17 and a plurality of connecting recesses 18, which are formed corresponding to one another.

(36) The rod-shaped body 1 according to this embodiment can also be manufactured by means of an extrusion process or an injection molding process, wherein first or second part 13, 14 are initially formed and subsequently the second or first part, respectively.

(37) In addition, according to the invention, an apparatus for belt tightening 2 is provided, which comprises a force transfer element according to the invention. The force transfer element 1 is thus also suitable for apparatuses for belt tightening 2 that are known from the prior art and partially shown in FIGS. 1A to 3C.

(38) Known belt tighteners 2 typically have a force transfer element, for example, a plurality of balls arranged in a row, which are initially stored in a tube and subjected to high pressure upon activation of a gas generator (FIGS. 1A to 1C).

(39) In doing so, the balls are pushed forward out of the tube and drive a drive wheel, which is coupled to the belt reel.

(40) Further force transfer elements used in known belt tighteners are racks, tracks, moldings, or even the compressed gas itself, which is produced by a gas generator (Figures).

(41) Such force transfer elements can be replaced with a correspondingly configured force transfer element 1 according to the invention.

(42) The force transfer element 1 can be formed from an elastically or plastically deformable material, wherein the material is preferably elastically configured in order to conform to the course of a curved guide of an apparatus for belt tightening 2, and wherein the drive wheel penetrates the material of the force transfer element upon activation of the drive unit (FIGS. 4 and 5).

(43) A deformable material is to be understood to mean a material that macroscopically deforms upon contact with the drive wheel, for example. Examples of this are EPDM materials of various Shore hardness (70-95 Shore), rubber, natural rubber, or (soft) thermoplastics.

(44) Furthermore, according to the invention, a method is provided for manufacturing a force transfer element 1 as described above.

(45) Preferably, the force transfer element 1 is manufactured from a plastic material by means of an injection molding process.

(46) Alternatively, the force transfer element can also be manufactured from two or more different plastics by means of a 2-component or multi-component injection molding process.

(47) Here, a plastic is liquefied (plasticized) with an injection molding machine and injected under pressure into a mold, the injection molding tool. In the tool, the material returns to the solid state by cooling or by a cross-linking reaction and is removed as a finished part after opening the tool. The cavity of the tool determines the shape and surface structure of the finished part.

(48) Furthermore, sliding tools 19 are provided in order to form a corresponding structure or the ribs in the casing wall 6.

(49) In addition, it is also conceivable according to the invention to manufacture the force transfer element by means of an extrusion process.

(50) During the extrusion, a thick, curable plastic compound is continuously squeezed out of a shape-defining opening (also referred to as a nozzle, die, or mouthpiece) under pressure. A force transfer element is then created having a structure corresponding to the cross-section of the opening.

(51) Co-extrusion is also possible for manufacturing the force transfer element.

LIST OF REFERENCE NUMERALS

(52) 1 Force transfer element 2 Apparatus for belt tightening 3 Axial direction 4 End wall 5 End wall 6 Casing wall 7 Axial rib 8 Transverse rib 9 Main axial rib 10 Secondary axial rib 11 Recess 12 Force transfer wall 13 First part 14 Second part 15 Connecting surface 16 Connecting surface 17 Connecting element 18 Connecting recess 19 Sliding tool