DE2917523C2 - Seat belt retractor - Google Patents

Description

characterized in that

h) the control disk (9a ^! is easily formed and a coaxial inertia ring (36, 50) is rotatably mounted on the control disk (9a),

i) the pawl (32) on the one hand on the control disc (9a) and on the other hand on the inertia ring (36, 50) about two axes (34 and 34) arranged at a distance from one another and parallel to the common axis of rotation of the control disc (9a) and inertia ring (36, 50) 52) is pivoted.

j) the pawl (32) is loaded into its rest position by a spring, which is arranged between the control disc (9a) and the inertia ring (36, 50) and the same in a rotational position associated with the rest position of the pawl (32) with respect to the control disc ( 9a) charged, and

k) the control disc (9a ^ and the locking disc ( 9b) mesh with one another by means of at least one axial pin (56) which is conical in order to support the pin (56) when the side teeth (11) of the locking disc (9b) and to completely relieve the associated toothing (21) fixed to the housing.

2. Device according to claim 1, characterized in that the pin connection (pin 56) is designed to be resilient in the circumferential direction and the fixed connection between the control disc (9a) and the locking disc (9b) is only provided for as long by associated stops (57, 58) remains in place until the locking disk (9b) engages in the associated toothing (21) fixed to the housing due to its axial displacement f> 5.

3. Apparatus according to claim 1 or 2 with

additional vehicle-sensitive belt strap blocking in the withdrawal direction, the control disc auhveist a circumferential toothing with which a locking member cooperates, which can be actuated by an inertia element responsive to certain vehicle accelerations, characterized in that the control disc (9a) is part of a pot-shaped cover (9a) in a manner known per se , 31) for the remaining teeth (11; 21; 30), the pawl (32) between the control disk (9a) and inertia ring (36,50), the inertia ring (36,50) and the locking disk (9b)

The invention relates to a device for rolling up the webbing of seat belts, especially for motor vehicles of the type specified in the preamble of claim 1.

Such devices with band-sensitive webbing blocking in the withdrawal direction are known (DE-OS 21 63 732). The locking disk and the control disk are each designed as an inertia disk and arranged on both sides of a support disk attached to one end of the winding shaft, on which the Control disk facing side the pawl is movably mounted, which with a radial Control cam cooperates on the control disc by a leg spring attached to the support disc is loaded into the rest position and with a protruding, resilient finger through a circumferential recess the support disk engages in a circumferential notch of the locking disk in a The control disk remains due to certain acceleration of the winding shaft in the webbing pull-off direction their inertial mass against the support disc back, so that the pawl through the control cam of the Control disk is moved from its rest position into engagement with the associated toothing fixed to the housing, by means of the resilient finger, the locking disk in a certain rotational position with respect to the To hold the housing, from which it is when the winding shaft continues to rotate in the webbing pull-off direction is axially displaced by the support disc to engage with its side teeth with the associated To come to the housing-fixed toothing, with a certain amount of play, which only with a slight last rotation of the winding shaft in the webbing pull-off direction with elastic deformation of the finger the pawl is overcome. An embodiment for vehicle-sensitive belt strap blocking can also be used be hit in the withdrawal direction by providing the control disc with circumferential teeth, with which a locking member cooperates, which of a certain accelerations of the provided with the device-vehicle responsive inertia element is operable.

A particular disadvantage is that the pawl is constantly loaded with each locking process and her resilient finger is bent, which is responsible for the reliable functioning of the known The device is essential because it represents the only connection between the control disk and locking disk. This stress is associated with an increased risk of breakage, especially when taken into account that the brittleness of the material of the pawl, usually a plastic, with falling

Temperatures increases In addition, in the formation of the known device for a vehicle-sensitive mode of operation, the pawl must also always be effective and stressed. The structure of the known device is also relatively complex because of the support disc relatively expansive in the axial direction and also of relatively high weight, in particular the massive support disc and the massive control disc also contribute. The one on the winding shaft The mounted locking disk is not guided in such a way that tilting can be ruled out with certainty.

The invention is based on the object of providing a device with band-sensitive webbing blocking To create withdrawal direction of the genus specified in the preamble of claim 1, at which the pawl is finally completely relieved in the case of blocking and a training with a such additional vehicle-sensitive mode of operation is possible in which this pawl is not effective is, but only the locking member which can be actuated by an inertial body responsive to certain vehicle accelerations and which is vehicle-sensitive in the vehicle initiated blocking case is also finally completely relieved.

This object is achieved by the features specified in the characterizing part of claim 1. Advantageous refinements of the device according to the invention are set out in the remaining claims marked.

In the device according to the invention, at a certain acceleration of the winding shaft in Webbing pull-off direction a relative rotation takes place between the light control disc and the inertia ring, so that the pawl engaging on the one hand on the control disk and on the other hand on the inertia ring from its rest position, in which it is moved by the spring acting between the control disk and the inertia ring is loaded, pivots in engagement with the associated toothing fixed to the housing, by means of the locking disk the or each conical axial pin in a certain rotational position with respect to the housing block, from which the locking disk is activated when the winding shaft continues to rotate in the webbing pull-off direction is axially displaced, which they with their side teeth in engagement with the associated housing fixed Interlocking comes. The pawl is only loaded during the said initial phase, since the subsequent axial displacement of the locking disk, the latter stops the conical axial pin or pins to be loaded before their side teeth on the associated toothing fixed to the housing to the plant comes to transmit the torque exerted on the winding shaft to the housing.

The device according to the invention can also be designed in a simple manner so that it In addition, a vehicle-sensitive belt strap blocking in the withdrawal direction causes, namely such a, at which is the pawl that is effective in the case of band-sensitive webbing blocking in the initial phase does not have to go into action, but only the locking member then still provided, which over it In addition, it is only burdened during the initial phase of every vehicle-sensitive blocking event and is then completely relieved, as described. It is opposite to the design according to the DIf-OS 21 63 732 insofar as the device is still more secure if the pawl fails works reliably via the locking member

Below is an embodiment of the device according to the invention with reference to the drawing for example described. It shows, in each case schematically

F i g. 1 shows the longitudinal section in the plane containing the axis of rotation of the winding shaft, in the upper different states are illustrated in the lower half;

FIG. 2 shows the partial side view in the direction of arrow V in FIG. 1, only part of the front control disk and the rear locking disk and the intermediate ring serving as an inertial body for moving the locking member on the control disk being shown; and

3 shows the side view according to FIG. 2, but according to slight rotation of the rear locking disk from the position according to FIG. 2 clockwise.

The device according to FIG. 1 has a housing 1 in which a winding shaft 2 is rotatably mounted and carries a webbing roll 3. The wound webbing 4 is fastened at one end to the winding shaft 2 and runs out of the housing 1 at the other end.

At one end of the winding shaft 2, namely the right end not shown in Fig. 1, engages Spiral spring with the flattest possible characteristic, which with the inner end on the winding shaft 2 with the outer end is attached to a cover which is connected to the housing 1. If the webbing 4 is off removed from the housing 1 when the seat belt is put on, the winding shaft 2 in the direction of the Arrow 7 (Fig. 2 and 3) rotates, then the spiral spring is tensioned, however, on the winding shaft 2 acting spring force increases only insignificantly due to the flat characteristic curve of the spiral spring. Will the Seat belt removed, then the webbing 4 is automatically drawn into the housing 1 and on the Winding shaft 2 rolled up, under the action of the winding shaft 2 against the arrow 7 driving Coil spring.

At the other end of the winding shaft 2, a ratchet wheel 9 with a circumferential toothing 10, a side toothing 11 and an internal thread 12 is provided. The ratchet wheel 9 is designed in two parts and consists of a round control disk 9a and a round locking disk 9b. The control disk 9a is provided with the circumferential toothing 10 and the locking disk 9b is provided with the side toothing 11 and the internal thread 12. Control disk 9a and locking disk 9b are mutually axially movable.

On the side facing away from the side toothing 11 and the winding shaft 2, the locking disk 9b has a cover-like section 13 which merges into a central hollow pin 14. This extends into a recess 15 on the adjacent end face of the winding shaft 2 and is guided in a sliding manner on an axial extension 16 provided on the winding shaft 2. In the recess 15 a compression spring 17 is arranged which surrounds the hollow pin 14 and is supported on the one hand on the winding shaft 2 and on the other hand on the locking disk 9b , namely on the inside of the cover-like section 13. At the free end of the winding shaft 2, a section 16.7 is reduced Diameter of the forts / cs 16 provided with a head 18, which the control disk 9 <7 on the section 16 ;; stop. The compression spring 17 presses the control disk 9b and the control disk 9.7. which with

a hollow pin 14a is rotatably mounted on the section 16a.

The winding shaft 2 extends with a sleeve-shaped section 19 into the locking disk 96. An external thread 20 is provided on the section 19, which cooperates with the internal thread 12 of the locking disk 96. Opposite their side toothing 11, a corresponding toothing 21 fixed to the housing is provided. The two teeth 11 and 21 cooperate, as will be described, and are out of engagement when the locking disk 9b on the control disk 9 ;? is applied.

To block the end of the belt on the vehicle side 4 in the withdrawal direction is to be ensured according to FIG. 1 below the control disk 9a a pawl-like The locking member 22 is mounted on the housing 1 so as to be pivotable about a horizontal axis. The locking member 22 rests on an inertia element designed as a ball, which is in a pot attached to the housing 1 with is arranged conical bottom. The pot is formed on a housing-fixed component 27 made of plastic, just like the toothing 21 fixed to the housing. The locking member 22 acts with a tooth-shaped projection 28 with the circumferential teeth 10 of the control disk 9a together, as described, and rests with a conical recess on the inertia element. In Fig. 1, only the tooth-shaped projection 28 of the locking member 22 is indicated.

A further toothing 30 fixed to the housing is provided, which extends around the locking disk 96 extends and inside on a cylindrical side projection 31 of the housing-fixed component 27 made of plastic is trained. A pawl 32 cooperates with this in a manner that will still be explained.

The pawl 32 is arranged on the control disk 9a so that it can pivot about an axis 34. To move the pawl 32 from the rest position in engagement with the housing-fixed toothing 30 is an inertial body 36. which is formed as a ring 50, which arranged coaxially to the control disk 9a and rotatable on a sleeve-shaped axial extension 51 of the same is stored. A compression spring, not shown, is located between the control disk 9a and the ring 50 provided, which presses the ring 50 with respect to the control disk 9.7 in such a rotational position that the pawl 32 is pivoted into the rest position. The pawl 32 is parallel to the axis 34 about a Axis 52 is pivotably connected to ring 50.

The two axes 34 and 52 are arranged at a distance from one another in such a way that upon rotation the control disk 9a in the direction of arrow 7 with respect to the ring 50 against the action of the interposed Compression spring, the pawl 32 is pivoted from the rest to the engaged position, as shown in FIG. 2 and 3 demonstrate.

The side toothing 11 of the locking disk 9b is formed by block-like projections 53 evenly distributed in the circumferential direction and having an approximately rectangular cross-section according to FIGS. 2 and 3 . 2 and 3 also formed approximately rectangular cross-section

As shown in FIG. 2 and 3, spring arms 55 are formed on the control disk 9a, each of which engages at the free end with a pin 56 parallel to the winding shaft 2 in a corresponding bore in the locking disk 9b , as can be seen in the upper half of FIG . In this way, the control disk 9a and the locking disk 9b can be freely moved axially with respect to one another, but are connected to one another so as to be rotatable to a limited extent. The spring arms 55 allow only a slight mutual rotation in the circumferential direction.

Furthermore, the control disk 9a has peg-like projections 57 on the side adjacent to the locking disk 9b , which each interact with an edge 58 of an opening in the locking disk 96, as will be described below.

The device works as follows. In the case of vehicle-sensitive operation, the locking element is 22 and in the case of band-sensitive operation, the pawl 32 is effective to move the control disk 9a in a defined Drehsteüung with respect to the housing fixed To keep toothing 21. In the rest position, the inertia element takes to actuate the Locking member 22 the lowest position in the associated pot, in the conical recess of the locking member 22 lying. The locking member 22 is out of engagement with the control disk 9a. The same is true of the pawl 32 held on the control disk 9a in that position in which the pawl 32 is outside Engagement with the toothing 30 fixed to the housing is located. The locking disk 96 is located with the side teeth 11 out of engagement with the associated, fixed to the housing Toothing 21, pressed by the compression spring 17 against the control disk 9a. The winding shaft 2 is so in Housing 1 freely rotatable, together with control disk 9a, locking disk 96 and ring 50.

Finds a relative acceleration between the inertia element for actuating the locking member 22 and the associated pot instead, caused by a corresponding acceleration of the device provided vehicle, then the inertia element moves out of the lowest position in the pot. This has the consequence that the locking member 22 with the tooth-shaped projection 28 in engagement with the Circumferential toothing 10 of the control disk 9a is pivoted, so that a rotation of the control disk 9a is blocked in the direction of arrow 7. The tension exerted on the belt strap 4 causes the winding shaft 2 however, rotated in the direction of arrow 7, so that the locking disk 96 on the winding shaft 2 against the Action of the compression spring 17 unscrews until the side toothing 11 with the toothing fixed to the housing 21 comes into engagement. The belt withdrawal from the housing 1 is then blocked.

In addition to this vehicle-sensitive mode of operation The pawl 32 becomes effective if a band-sensitive mode of operation is possible. If the ratchet wheel 9 accelerated in the circumferential direction in such a way that the acceleration exceeds a certain limit value of for example exceeds 1 g, then this has the consequence, that the pawl 32 is pivoted in order to engage in the associated toothing 30 fixed to the housing. As a result, the control disk 9a (as in the case of a vehicle-sensitive mode of operation by the locking member 22) in a specific rotational position with respect to the housing 1 or the toothing 21 fixed to the housing blocked With this band-sensitive mode of operation, that rotary position of the ratchet wheel 9 is also with respect to the housing 1 and thus the toothing 21 fixed to the housing precisely defined in which the Locking disk 96 is axially displaced. The side teeth 11 of the locking disk 96 and the associated, Toothings 21 fixed to the housing are arranged in this way.

that in the said axial movement of the locking disk 9b a perfect mutual engagement is guaranteed. The two toothings 11 and 21 cannot come to stand tooth on tooth even if the device functions in a band-sensitive manner.

The pawl 32 therefore swivels into engagement with the associated toothing 30 fixed to the housing, because the ring 50, due to its inertial mass, remains behind the control disk 9a when, when the belt strap 4 is jerked off the winding shaft 2, it jerks in the direction of arrow 7 (Fig .2 and 3) moves. If the winding shaft 2 is then rotated further in the direction of arrow 7, it is screwed into the locking disk 9b held by the control disk 9a, so that the latter moves axially away from the control disk 9a against the action of the compression spring! the openings 54 to run as shown in FIG. 2 shows.

As soon as the locking disk 9b with the opening edges 58 acting as stops has run away from the projections 57, which also act as stops, the locking disk 9b can continue to rotate in the direction of the arrow 7, due to the resilient connection with the control disk 9a by the spring arms 55, to with the Projections 53 each rest on the corresponding side edge of the associated opening 54, as shown in FIG. 3 can be seen, so that any further rotation of the winding shaft 2 in the direction of arrow 7 is blocked, wherein the torque exerted on the winding shaft 2 via the eingreifen- in the openings 54 Jo the projections 53 of the lock plate 9b of the housing 1 and the thus connected component 27 is transferred. The pawl 32 is relieved of this force transmission except for the small force of the spring arms 55. J5

In the upper half of FIG. 1 shows the device in the state with the locking pawl 32 in the rest position and the locking disk 9b not actuated, in the lower half in the state with the locking pawl 32 and axially displaced locking disk 9b in the engaged position, the locking pawl 32 being shown in both cases, although actually only one pawl 32 is provided. Also in FIG. 2 and 3, the resilient reciprocal movement of locking disk 9b and control disk 9a in the circumferential direction are exaggerated for better understanding.

In particular, F i g. 1 shows that the two-part design of the ratchet wheel 9 makes it possible to arrange the locking member 22 inclined relative to the plane of the control disc 9a without impairing the reliable, vehicle-sensitive mode of operation, since in the event of a blockage the control disc 9a does not move axially, but only the locking disc 9b shifts in the axial direction. This means that the device does not necessarily have to be installed with an approximately horizontal winding shaft 2, as shown, but can also be installed with an inclined winding shaft 2.

The band-sensitive webbing blocking in the pull-off direction takes place, for example, when the vehicle-sensitive belt strap is not blocked in the withdrawal direction is possible, for example because the locking member 22 is broken or some other component required for this has failed The sensitivity of the device with band-sensitive webbing blocking in the pulling direction for reasons of comfort when putting on the seat belt is preferably about 1.2 to 1.5 g.

In the illustrated apparatus, the same with the pawl 32 of the control plate 9a cooperating housing-fixed spline 30 tooth pitch on how the other fixed to the housing teeth 21. This corresponds to the side teeth 11. The tooth pitch of the peripheral teeth 10 of the control disk 9; i, with which the blocking member 22 interacts with a vehicle-sensitive mode of operation, likewise corresponds to that of the toothing 21 fixed to the housing.

The circumferential toothing 10 can also be provided on the outside of a cup-shaped cover which is attached to the control disk 9a is attached or formed and with its cylindrical side wall the cylindrical Side projection 31 of the housing-fixed component 27 encloses so that all components for blocking the Winding shaft 2 are encapsulated, apart from the circumferential toothing 10 of the control disk 9a, the cooperating locking member 22, the inertia element for actuating the same and the pot to accommodate the inertia element.

From the described mode of operation it follows that the inertial mass of the ratchet wheel 9 is not essential. The ratchet wheel 9 can therefore be of light construction. These Design as a component with the lowest possible inertial mass is preferred, in particular for the control disk 9a.

It is not absolutely necessary to provide an internal thread 12 or an external thread 20 for axial displacement of the locking disk 90 on the axial extension 16 of the winding shaft 2 when the locking disk 9b and winding shaft 2 are mutually rotated. It is only essential that between locking disk 9b and winding shaft 2 there are inclined control surfaces in such a way that the aforementioned axial movement of locking disk 95 occurs.

However, instead of the connection between the control disk 9a and locking disk 9b, which is to a certain extent resilient in the circumferential direction, a type of screw connection is provided in that the axial pins 56 are rigidly arranged on the control disk 9a and are conical, converging away from the control disk 9a, each with an opening edge to cooperate on the locking disk 9b , similar to the projections 57, which cooperate with the opening edges 58 in order to prevent the slight rotation of the locking disk 9b for the mutual abutment of the block-like projections 53 and the openings 54 according to FIG. 3 to come about towards the end of the axial movement of the locking disk 9b away from the control disk 9a. Instead of providing the projections 57, however, it is also possible, for this purpose, to configure the pins 56 conically only at the end section remote from the control disk 9a.

In principle, only one pin 56 is required, just as only one pin-like projection 57 needs to be provided, if at all. However, several such organs are advantageously provided, distributed in the circumferential direction. It is also possible to reverse the arrangement of the rigid, conical pin (s) 56, i.e. to rigidly arrange the pin (s) 56 on the locking disk 9b and allow it to interact with a control edge of the control disk 9a, as does the pin-like protrusion (s) 57 the locking disk 9b and the opening edge or opening edges 58 can be provided on the control disk 9a.

For this purpose 2 sheets of drawings

Claims (1)

Patent claims: 1. Device for rolling up the webbing of seat belts, especially for motor vehicles, with band-sensitive webbing blocking in the withdrawal direction, in which a) a housing with two teeth, b) a winding shaft rotatably mounted in the housing, c) with a spring-loaded locking disk which can be screwed with respect to the winding shaft and is spring-loaded in the rest position a side toothing, d) a movably mounted, spring-loaded pawl in the rest position and e) a control disk rotatable with respect to the winding shaft, but axially fixed, is provided are which f) the pawl at a certain acceleration of the winding shaft in the webbing pull-off direction moved from its rest position into engagement with a toothing fixed to the housing to to block the locking disk in a certain rotational position with respect to the housing, so that g) the winding shaft disengages the locking disk with further rotation in the webbing pull-off direction their rest position moves axially and with their side teeth in engagement with the brings another toothing fixed to the housing,