Adjustment mechanism for an occupant support

A height adjustment device of a motor vehicle seat and a method for the production thereof includes a transverse pipe and a pair of links. The transverse pipe has two end-side bearing regions which merge in a central region having a larger diameter and each link rests on a bearing region of the transverse pipe.

PRIORITY CLAIM

This application claims priority to German Patent Application No. DE 10 2017 108 218.2, filed Apr. 18, 2017, which is expressly incorporated by reference herein.

BACKGROUND

The present disclosure relates to an occupant support, and particularly to a vehicle seat. More particularly, the present disclosure relates to a height adjustment device for a vehicle seat.

SUMMARY

According to the present disclosure, a height adjustment device of a motor vehicle seat and a method for the production thereof includes a transverse pipe and a pair of links. The transverse pipe has two end-side bearing regions which merge in a central region having a larger diameter. Each link rests on a bearing region of the transverse pipe via a bearing hole.

In illustrative embodiments, the transverse pipe has a first diameter over the entire length thereof. The two ends of the transverse pipe are reduced to a second diameter in order to provide the bearing regions. The central region of the transverse pipe located between the bearing regions maintains the first diameter. A diameter step is provided as a result of this forming between the central region and the bearing regions. The diameter step may be constructed in a conical manner, that is to say, for example, by means of a frustoconical transition.

In illustrated embodiments, the bearing regions receive the links via the bearing holes. The links are pushed onto the bearing regions until each link is in abutment against the diameter step with respect to the central region. Subsequently, an axial force is applied to the link and/or the transverse pipe in order to cold-form the transverse pipe in the region of the diameter step. The conical abutment shoulder of the bearing hole runs up against the diameter step with respect to the central region, and the diameter step is deformed into a conical abutment face which engages the abutment shoulder. At least a portion of the transverse pipe is received in the four axial grooves of the bearing hole.

DETAILED DESCRIPTION

A motor vehicle seat1as shown inFIG. 1includes a seat member2and a backrest3. The motor vehicle seat1is supported by means of upper rails4which are displaceably arranged in lower rails6which are secured to the vehicle floor5so as to be able to be longitudinally displaced on the vehicle floor. Furthermore, the motor vehicle seat1is provided with a height adjustment device. Two front links7and two rear links8belong to this height adjustment device. The front links7rest in a rotationally secure manner on a front transverse pipe (not shown) which is supported with the ends thereof rotatably in a seat member side frame (not shown). The rear links8rest in a rotationally secure manner on a rear transverse pipe9whose ends are constructed as bearing regions9.1. With these bearing regions9.1, the transverse pipe9is in each case rotatably supported in a hole of the seat member side frame. The lower ends of the front links7and the rear links8are rotatably connected to the upper rails4. To this end, they have at the lower ends thereof corresponding bearing openings10.

In order to adjust the height of the motor vehicle seat1, there is provided at a seat side a height adjustment pump which is not illustrated and which is actuated by means of an operating lever11. The height adjustment pump has a pinion which meshes with a tooth segment12of one of the rear links8. As a result of a corresponding pump movement with the operating lever11, the pinion of the adjustment pump acts on the tooth segment12of the link8so that it pivots in one or the other direction about the lower bearing location. This pivot movement is transmitted via the front transverse pipe and the rear transverse pipe8and via the seat member side frame to the other links7,8so that the motor vehicle seat1is on the whole adjusted upward or downward.

The securing of the links8to the rear transverse pipe9is explained below by way of example with reference to the link8having the tooth segment12. The securing of the other link8which is not directly driven is carried out in a similar manner.

In the starting state, the transverse pipe9has a diameter d1over the entire length thereof. In a first operating step, the two ends of the transverse pipe9are reduced to a diameter d2in order to provide the bearing regions9.1. The central region9.2of the transverse pipe9located between the bearing regions9.1maintains the diameter d1. A diameter step is provided as a result of this forming between the central region9.2and the bearing regions9.1. The diameter step may be constructed in a conical manner, that is to say, for example, by means of a frustoconical transition.

The link8is provided with a bearing hole13whose diameter is slightly greater than the diameter d2of the bearing regions9.1. The bearing hole13has a conical abutment shoulder14whose flanks define an opening angle of α=60° between them. Approximately at the center of the sheet thickness b of the link8, the abutment shoulder14merges into a cylindrical wall15of the bearing hole13. This construction can best be seen inFIG. 7.

In the bearing hole13, there are formed four axial grooves16which are each arranged so as to be distributed with a spacing of 90° around the periphery. This construction can best be seen inFIGS. 5 and 7.

In another operating step, the link8, is pushed by means of the bearing hole13thereof onto the bearing region9.1until it is in abutment against the diameter step with respect to the central region9.2. Subsequently, an axial force is applied to the link8and/or the transverse pipe9in order to cold-form the transverse pipe9in the region of the diameter step. During this operation, the conical abutment shoulder14of the bearing hole13runs up against the diameter step with respect to the central region9.2, whereby the diameter step is deformed into a conical abutment face17which is in abutment with the abutment shoulder14. In the deformation operation described, material of the transverse pipe19flows simultaneously into the four axial grooves16of the bearing hole13. The link is now axially secured on the transverse pipe9in a rotationally secure manner and in the direction toward the central region9.2.

The axial securing of the link8in the direction toward the central region9.2is carried out only at the diameter step, whereby the need for an otherwise conventional inner bead is eliminated. The starting length of the transverse pipe9can thereby be correspondingly shorter, whereby material is saved.

The opening angle of α=60° of the abutment shoulder14of the bearing hole13promotes the cold-forming operation. Since the abutment shoulder14and the support face17are in abutment with each other in an oblique plane, during use of the height adjustment device, a gentle force dissipation is produced which has a positive effect on the service-life of the connection between the link8and transverse pipe9.

In order to complete the connection between the link8and transverse pipe9, there is then formed in the bearing region9.1an outer bead18which is in abutment with the link8from the outer side. In this state, this link is axially secured in both directions to the transverse pipe9. In the bearing region9.1, another bead19is formed with spacing from the outer bead18. This bead acts as a stop on the seat member side frame.

Prior devices may include multiple beads or an inner bead and may be very material-intensive which has to be compensated for by the provision of a transverse pipe with a correspondingly longer starting length. Furthermore, the inner beads are subjected to significant loads which leads to a shortening of the service-life of the connection between the transverse pipe and the links. In illustrative embodiments, the present disclosure provides a height adjustment device with increased service-life, less material-intensive, and simpler to produce.

In illustrative embodiments, the transition from the central region to the bearing regions of the transverse pipe is carried out via a diameter step, whereby a bead is no longer required at this location. Material is thereby saved, that is to say, the starting length of the transverse pipe may be correspondingly shorter. This may save costs and weight.

Since in the contact region between the bearing regions and the central region conical faces are in abutment with each other, during use of the height adjustment device there is produced a protective discharge of forces between the link and transverse pipe, whereby the service-life of this connection is increased and substantially perpendicular faces are in abutment with each other. The conical abutment shoulder further has the advantage that it promotes the flow behavior of the material during cold-forming.