GB2207346A

GB2207346A - Height adjustable head rest

Info

Publication number: GB2207346A
Application number: GB08816087A
Authority: GB
Inventors: Klaus Dieter Bertram; Bernd Kluting
Original assignee: Keiper Recaro GmbH and Co
Current assignee: Keiper Recaro GmbH and Co
Priority date: 1987-07-10
Filing date: 1988-07-06
Publication date: 1989-02-01
Anticipated expiration: 2008-07-06
Also published as: GB2207346B; JPS6422208A; DE3722856A1; GB8816087D0

Description

v G i HEADREST INSIGHT ADJUSTER

The invention relates to head rests in vehicles and having Claim 1.

2207346 a device for adjusting the height o-.,':

the features.in the preamble to In the c'ase of vehicle seats equipped with prior art height adjusting devices of this type, the seat user in many cases neelects to ensure correct height adjustment of the head r.estraint or head rest, because the process-of adjusting the head rest is quite inconvenient for the user. Every adjusting operation makes it necessary to lift the ratchet elements of the ratchet means out of the notches in the head rest support bars, which can be performed only by the exertion of a not inconsiderable force by the user. Therefore, since in many instances the head rest is not correctly adjusted in height, the user is unfavourably exposed to serious disadvantages with regard to safety.

The invention is based on the problem of'providing a remedy by providing a height adjustment device in which acturate ad ust 0 j ment of the height of the head rest can be carried out in a par ticularly simple and convenient manner.

According to the invention, this problem is resolved by a height adjusting device having the features according to Claim 1.

According to the invention, by virtue of the fact that at the support rod guide not only these are mounted for displacement in the longitudinal direction of the guide but the ratchet means are also mounted for longitudinal adjustment on the guide, it is possible for the support rods to be adjusted in their guide bv a corresponding displacement movement of the ratchet means, brought about by a positioning device. This infinite adjustment of the height of the head rest occurs without slackening the ratchet means and by a corresponding actuation of the positionin. device. Thus it is possible very easily to achieve a fine 0 1 G.

1 1 i and infinite adjustment of the head rest to a desired hei-,llt,.SO avoidin- the danoer of the seat user resortina to the convenience. of neglecting to adjust the hea rest correctly according to his requirements.

Actuation of the positioning device for adjusting the ratchet means along the guide provides for an infinite fine adjustment of-the head rest within a specific range of adjustment determine d by the length of the displacement pathon the guide. For adjusting measures which go beyond this range, as with conventional height adjusting devices, the ratchet means must be released and -a coarse adjustment carried out in the usual way by renewed engagement into another desired ratchet notch on the support bars. After the coarse adjustment has been made, then, the seat.user, once he has assumed his seated position, can carry out the fine adjustment by actuating-the positioning device, preferably while seated.

By reason of the fact that the support bars are not formlockingly connected to the guide or to the locking device provided-for adjusting the ratchet means, but are'connected via the ratchet means on the support bars, any high loadings which affect the head rest need not be accommodated by the height adjustment device because only the reaction forces of the ratchet meads are introduced into the height adjustment device, and these disengage in the event of any forces engaging the head 0 0 0 rest which exceed the locking effect of the ratchet means.

In the case of an advantageous example of embodiment according 0

Claims

to Claii.R 2, it is envisaged that the guide have a fra,-,ie adapted

0 to be fixed on the back rest, so that the height adjusting a 0 device-can be very easily fixed on the padding carrier of the back rest as a component unit.

According to Claim 3, it is 'possible to have the carrier constructed in the form of a bridge extending at a right-angle to the longitudinal direction of the guide, from support rod to 0 0 1 1 1 1 1 1 priced construction.

support rod. This provides for a low weight and The fra-e servino as a cuide for the two support bars of the head rest and the bridge carrying the ratchet means can advan- 0 tageously be composed of two synthet.ic plastics half shells, 0 - which are of identical construction and which can be fixed to each other by interengaging snap-action' connecters, which is 0 likewise weight and cost saving.

In the case of a further advantaceous example of embodiment, mounted on the frame in such a way as to be rotatable and axially non-displaceable there is extendin6 in the longitudinal direction of- the guide a threaded spindle which is part of the positioning device which is in screwthreaded engagement with a threaded bush seated in the central portion of the bridge mounted for displacement on the frame and supporting the ratchet means'. In consequence, a particularly simple drive is obtained.

ating device connected to the threaded spindle via a coupling could be a manually operable rotary knob or the like which could be connected to the threaded spindle via a 1 flexible shaft. However, it is more convenient to have t drive provided by an electric motor which may be likewise coupled to the threaded spindle via a flexible shaft.

The invention i reference to drawings, in 0 Fic. 1 1 s a dev head Fig. 2 shows a section taken on the line II-II in Fig. 1, without the support bars being shown in the drawing., s explained in greater detail hereinafter with an example of embodiment shown in the accompany-ing which:

front view of an embodiment of height adjusting ice with_broken-away support bars of an associated Fias. 3 and 4 are sections corresponding to the section lines iII-III and IV-IV respectively in Fig. 1, and 0 1. '.1 The height adjusting device has, shown in front view in Fig. 1 and generally designated 1, a guide for two support rods 3, of which the top ends are connected to a not shbwn padding carrier of a likewise not shown head rest of conventional type. The guide 1 takes the form of a rectangular frame 2 which comprises fixing holes 5 and fitting bores 6, by means -of which the frame 2 can be bolted to carrier parts of the back rest of an associated vehicle seat (not shown). As can be seen p articularly clearly in Figs. 3 to 5, the frame 2 is composed of two identically constructed half shells, which in the example of embodiment 'shown may be synthetic plastics injection moulded parts.

- 4 Fio. 5 is a broken-away partial section taken on the line V-V in Fig. 1 and drawn on a 1,arger scale compared with t.lie other figures.

The half shells comprise projecting snapaction lugs 7 and apertures 9 (see particularly Fig. 5) through which these engage, and-also centring projections 11 which engage centring holes 12 (see Fig. 3). With its upper marginal leg 13 and its bottom marginal leg 15 which extend at a right-angle to the axis of the support rods 3, i.e. at a right-angle to the longitudinal guide axis of the guide 1, the frame 2 forms guide bushe. s 17, see Fig. 4, in which th! support rods 3 are guided for longitudinal displacement.

As is shown in Fig. 1, the support rods 3 comprise offset to one another in the longitudinal direction of the support rod 3, a plurality of notches 19 provided in conventional manner for co-operation with a respective ratchet means generally designated 0 and associated with each support rod 3. Each ratchet device is disposed on an associated end of a carrier in the form of a beam-like bridge 21 of synthetic plastics material and extending from support rod to suppor t rod. The bridge 21 is -widened 0 0 out at both ends to form a bus,,T 23 which surrounds te relevant support rod 3. In a position flush with the notches 19 of the support rods 3, the wall of each bush 23 comprises a cut-out k (1 4 1 a seat for a ratchet member 25 (see in particular Fip. 5) mounted for movement in th,e cut-out, the ratchet member being initially biased by a ratchet spring for separable enoacement into one of the notches 19 of the support rod As 0 0 L L Figs. 1 and 5 show, the ratchet spring is constructed as a spring M clip 27 seated in an annular groove 29 in the outer wall of the bush 23 of the bridge 21.

As can be seen particularly from Figs. 3 to 5, the areas of the mutually facing inner walls of the half shells of the frame 2 which extend at a distance from one another form a sliding path for the bridge 21 which is accommodated between them. Guided for displacement in this slide path is the bridge 21 which is adapted to move in the longitudinal direction of the guide, -i.e. in the longitudinal direction of the support rods 3. As part of the slide path there.are, extending in the longitudinal direction' of....the guide and constructed in the inside walls of the half shells, depressed grooves 31 and projecting guide ribs 33 on the bridge 21, which are adapted to engage the grooves. As Figs. 1 and 3 show, the grooves 31 and guide ribs 33 are disposed in theregion between the bushes 23 at the bridge end and the middle central portion 35 of the bridge 21.

9 In the middle portion which is directed at the central portion 35 of the bridge 21, the upper arm 13 and lower arm 15 of the frame 2 each form a bearing bush 37 and 39 for an upper and lower respective bearing sleeve 41, 43 rotatably mounted in the bearing bushes 37, 39, secured by a respective widened sleeve shoulddr 45 to prevent axial displacement in either axial direction. The inner bore of each bearing bush 37 and 39 is engaged by the end zones of a threaded spindle 47, the threaded spindle 47 being rigidly, i.e. axially immovably and rotationally rigidly, connected to the bearing bushes 41 and 43 by driwe pins 49 in the sleeve shoulders 45.

1 The threaded spindle 47 is part of a positionina device gener 0 ally designated 51 and by means of which the bridge 21 carrying 0 v the ratchet means 20. is displaceable in the longitudinal direc- tion of the guide, i.e. in the longitudinal direction of the 0 suDD6rt rods 3, lengthwise of the sliding path formed between 0 the hal-Lr shells of the frame 2. The displacing device 51 likewise includes a screwthreaded sleeve 53 which is injection moulded into the bridae 21 in its widened central portion 35, the 0 threaded sleeve 53 being in screwthread ed en-agement-with. the threaded spindle 47 passing through it.

Both bearing bushes 41 and 43 have at the outer end a square hole 55, 57 for forming a coupling connection to a rotary actua- 0 ting device. In the case of the example of embodiment, the square nipple oh the output end of a flexible shaft 59 is inserted into the square hole 57, the flexible shaft 59 being connected to a motorised drive which is not shown.

Via the threaded sleeve 53 of the bridge 21, the rotary movement of the threaded spindle 47 which is brought about via the flexible shaft 59 produces a displacement movement of the bridge 21 lanathwise of the sliding path between the half-shel ls of the frame 2. In this respect, the bridge 21 is secured against possible tilting during the displacement movement, by means of the lonaitudinally extending guide ribs 33 which are guided in the guide grooves 31 of the half shells of-the frame 2. Upon the adjustment movement of the bridge 21, there is a corresponding adjustment movement of the support rods 3 which are forcelockingly connected-to the bridge 21 via the ratchet means 20. If there are sudden intense loadings which act on the head rest from above, the ratchet members 25 of the ratchet means 20 are disen-a-ed from the notches 19 of the support rods 3, so that such loadings as exceed the retaining force of the ratchet means 20 do not need to be accommodated by the positionin. g device 51.

Motorised actuatio-n-which occurs via the flexible shaft 59 permits of remote control for fine adjustment of the head rest. If the square hole 55 at the top bearing bush 41 on the back rest of the relevant vehicle seat is accessible, then in order __j 1 'T 1 C. 1 c, 1 1 1 S 11 - 7 to produce a coupling connection, the upper square hole 55 can be used for making a coupling connection to a manual actuating device, for example a hand crank or a hand wheel. In addition to the infinitely variable fine adjustment of the head rest whic ' h can be brought about by means of the positioning device 51, displacement in steps is possible in conventional manner in that the user disengages the ratchet means 20.

All the features mentioned in the foregoing description and those which can be discerned purely from the drawings are as further developments constituent pQrts of the invention, even if they have not been particularly stressed and in particular even if they are not mentioned in the Claims.

W 1 1 CI I 11 -1 P a t e n t c 1 a i m s 1. A height adjusting device for head rests of motor vehicle seats, in which for two spaced-apart and at least substantially parallel support rods of the head rest, a guide is provided which is required to be fitted on the back rest of the vehicle seat, in which the support rods are displaceable in the longitudinal direction of the guide for adjusting the height of the head rest, beina adapted to be separably fixed in selected positions in relation to the lockin. means by ratchet means provided on the cuide and co-operating with notches in the support rods, characterised in that the ratchet means (20) are disposed for infinitely variable adjustment on the guide (1) in dinal-direction thereof and in that a positioning is associated with them.

the longitudevice (51) 2.Aheight adjusting device according to Claim 1, characterised in that the guide (1) has, adapted to be fixed to the back rest, a frame (2) which forms, extending in the longitudinal direction of the guide, a slide path on which there is guided for lon-itudinal displacement a carrier by which are held the ratchet means (20) for both support rods (3) and guided for longitudinal displacement for the adjusting movement of the ratchet means (20).

3.Aheight adjusting device according to Claim 2, characterised in that the carrier is constructed in the form of a bridge (221) extending at a right-angle to the longitudinal direction to the 0 0 Cuide and from support rod (3) to support rod (3), the bridge 0 - (21) having at each of its two ends one of the two ratchet 1 means (20) while its central portion (35) located midway be-ween the ratchet means (20), co-operates with the positioni:device (51).

1 adjusting device according toClaim 3, characterised in that the frame (2) is made from- two identicallv construcied I ii 1 i i 1 s which can be connected to each other by snap-action connecters,(7,.9), the half shells, when assembled, forming guide bushes' (17) for the displaceablejilour,-lg of the support rods (3) and enclosin. between tem the 0 slide path for the bridge (21) carrying the ratchet eans (20) 4 of each support rod (3).

S.A height adjusting device according to' Claim 4, characterised in that in the mutually facing inner walls of the half shells of the frame (2), there are constructed as parts of the slide path for the bridge (21) guide grooves (31) disposed in the region between each bridge end and the central portion (35) of the bridge (21), the guide grooves (31) extending in a lon-itudinal direction of the guide and being provided for cooperation with projecting guide ribs (33) of the bridge (21) which extend in the longitudinal direction of the guide.

6.Aheight adjusting device according to Claim 5, characterised in that the bridge (21) is at each end widened out to form a bush (23) through which passes the associated support rod (3) and in that the walls of each bush (23) comprise an apertuTe to serve as a seat for the associated ratchet member (25), being initially tensioned by a respective and associated ratchetsprin.g (27) for engagement into the notches (19) on the relevant support rod (3).

A hei-ht adjustina device according to one of Claims 3 to 6, 0 0 characterised in that the positioning device (51) has disposei in the central portion (35) of the bridoe (21) a threaded sleeve (53) which is in screwthreaded enoaoement with a threaded spindle (47) extending through it in the direction of the guide, the.spindle (47) being at both ends mounted on the frame (2) to be rotatable ',and axially while at least at one end, preferably the bottom end remote from the head rest, it has a coupling (57) for th of a rotation actuatino device.

0 e ccnnecti.on . 5.

1 - 10 8. A height adjusting device according to Claim 7, characterised in that the threaded spindle (47) comprises a coupling (57) for the connection of a preferably motor driven flexible shaft (59).

9. A height adjusting device substantially as described herein with reference to the accompanying drawings.

Published 1988 at The Pw.en'. Office, State 1-1cuse. t6 71 Ilil- Hclborn. London WC1R4TP- Further P0Dies may be ob-,aned from Tbe Patent Office.

Sales Branch. St Mary Cray. Kent LF, 3Rl- Pilnted by ltd. St Mary ks,. Kent Con. 1 a-.- 1 j i r. C i i 11 1! '.Ji 1 i i 1 1 1 1