Headrest

Abstract

A headrest has a base carrying the headrest on a seat, a head piece forming an abutment for a head, and a four-bar linkage including a first link and at least one second link therebehind in a direction of displacement. Each link is secured at one pivot with the base and at another pivot with the head piece such that the head piece is movable by the four-bar linkage relative to the base between a first end position and a second end position. An adjuster can alter and/or arrest the relative position between one of the links and the head piece, or between one of the links and the base. This adjuster has a first slotted link fixed on one of the first and second links, a second slotted link fixed on the head piece or the base, and a slide block engaged in slots of the first and second slotted links.

Claims

1. A headrest comprising: a base carrying the headrest on a seat, a head piece forming an abutment for a head, a four-bar linkage including a first link and a second link therebehind in a direction of displacement, each link being secured at a pivot with the base and a pivot with the head piece such that the head piece is movable by the four-bar linkage relative to the base between a first end position and a second end position, and an adjuster that alters and/or arrests the relative position between one of the links and the head piece, or between one of the links and the base, the adjuster having: a first slotted link fixed on one of the first and second links, a second slotted link fixed on the head piece or the base and having a longitudinal central axis, and a slide block engaged in slots of the first and second slotted links and movable along a motion path corresponding to the longitudinal central axis from a primary end of the first slotted link to a secondary end during movement of the head piece between the first position and the second position.

2. The headrest according to claim 1, wherein the adjuster includes a drive coupled to the slide block.

3. The headrest according to claim 2, wherein the adjuster includes a transmission to convert movement of the drive into movement of the slide block.

4. The headrest according to claim 3, wherein the transmission comprises a spindle rotatably driven by the drive, the spindle moving a spindle nut connected to the slide block, or the transmission comprises a spindle that is rigidly connected with the slide block, the spindle nut being rotatably driven by the drive.

5. The headrest according to claim 1, wherein each link is formed by two link elements connected with one another and pivoted on opposite ends of the head piece.

6. A headrest comprising: a base carrying the headrest on a seat, a head piece forming an abutment for a head, a four-bar linkage including a first link and a second link therebehind in a direction of displacement, each link being secured at a pivot with the base and a pivot with the head piece such that the head piece is movable by the four-bar linkage relative to the base between a first end position and a second end position, and an adjuster that can alter and/or arrest the relative position between one of the links and the head piece, or between one of the links and the base, the adjuster having: a first slotted link fixed on one of the first and second links, a second slotted link fixed on the head piece or the base, a slide block engaged in slots of the first and second slotted links, a spindle secured in the base and threadedly engaged with the slide block or a spindle nut on the slide block, and a rotary drive connected to the spindle or to the spindle nut for rotating the spindle and thereby shifting the slide block relative to the base.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Further advantages result based on one of the embodiments schematically shown in the drawing. Therein:

(2) FIG. 1 is a side view of the headrest with an adjuster merely partially shown,

(3) FIG. 2 is a side view of the head piece of the headrest,

(4) FIG. 3 schematically shows a subassembly including a base as well as a four-bar linkage of the headrest,

(5) FIG. 4 is a front view of the headrest,

(6) FIG. 5 is a side view of the headrest according to view arrow A in FIG. 4 in a first, rear position,

(7) FIG. 6 is a side view of the headrest according to FIG. 5, but with the head piece in an intermediate position between the first position and a second position, and

(8) FIG. 7 is a side view of the headrest according to FIG. 3 in the second, forward position.

SPECIFIC DESCRIPTION OF THE INVENTION

(9) The headrest is referred to generally with reference character 10. The same reference characters in the different Figures refer to the same parts, even if lower-case letter postscripts are used or omitted.

(10) The headrest includes a head piece 11 with a head-support face 12 that serves as an abutment for the unillustrated head of a seat occupant of a vehicle. The headrest 10 includes a base 13 with which the headrest 10 is fastenable to the vehicle seat. The base can for this purpose for example comprise guide bars that are mountable and arrestable in guide sleeves anchored in the seat. Alternatively, the base can however be fastened to the seat or the vehicle structure in any conceivable way.

(11) A four-bar linkage 14 is formed by pivotal links between the base 13 and the head piece 11. The four-bar linkage 14 includes a first link 15 and a second link 16. The link 15 is connected by at least one pivot G.sub.1, in particular two coaxial pivots G.sub.1, with the base 13 and at least one pivot G.sub.3, in particular two coaxial pivots G.sub.3, with the head piece 11. The link 16 is connected by at least one pivot G.sub.2, in particular two coaxial pivots G.sub.2, with the base 13, and at least one pivot G.sub.4, in particular two coaxial pivots G.sub.4, with the head piece 11.

(12) In this way, the head piece 11 is moveable in directions x.sub.1 and x.sub.2 between a first position shown in FIG. 5 and a second position shown in FIG. 7. Due to the mounting on the four-bar linkage 14, the head piece 11 in each position assumes a defined angular position relative to the four-bar linkage 14. In other words, an angle between the longitudinal central axis of the link 15 and for example a lower side of the head piece 11, and the angle between the longitudinal central axis 15 and for example an outer surface of the base 13 change on movement between the first position and the second position.

(13) At least one first slotted link 17 whose longitudinal central axis 31 (see FIG. 3) extends parallel to a longitudinal central axis 32 of the link 15 and is fixed to one of the links 15 or 16 (see FIG. 3), in the present embodiment with the first link 15. The first slotted link 17 is formed in a slotted link portion 22 that is not shown in FIGS. 5 to 7 for the sake of the overview.

(14) At least one second slotted link 18 is fixed (see FIG. 2) to the head piece 11. The slotted link 18 can for example be molded onto the head piece 11 or fastened thereto. A longitudinal midline 33 (FIG. 1) of the slotted link 18 follows a path of movement followed by an adjusting element 19 that moves, during movement of the head piece 11, between the first position and the second position, from a primary end of the slotted link 17 to a secondary end 21, and it engages into the slotted link 17 and into the slotted link 18. The adjusting element 19 is part of an adjuster 36.

(15) According to FIG. 4, the adjusting element or slide block 19 is formed from the end 23 of an axle 24. The axle 24 is fastened to a spindle nut 25, so that the adjusting element 19 is indirectly fastened to the spindle nut 25. In the embodiment, two axles 24 extend from the spindle nut 25 in opposite directions and respectively form the adjusting element 19 that acts together with slotted links 17 and 18 that flank the head piece 11.

(16) In the present embodiment, the first link 15 comprises two links 26a and 26b, movably connected with and spaced from each another and each connected with a respective first slotted link 17. The second link 16 likewise comprises two such movably connected links, of which only one is shown. Further, a second such slotted link 18 is formed on each of the opposite end faces 34a and 34b of the head piece 11.

(17) The spindle nut 25 is provided with an internal thread 27 that meshes with an outer thread 28 of a spindle 29. The spindle 29 is rotatable around a longitudinal central axis 35 in the directions u.sub.1 and u.sub.2, and is drivable in the rotational directions u.sub.1 and u.sub.2 by a drive 30, in particular a motor to move the spindle nut 25 in directions z.sub.1 or z.sub.2, depending on the rotation direction. In this way, the slide block 19 is movable between the ends 20 and 21 of the slotted link 17, and adjusts the relative position between the head piece 11 and the four-bar linkage 14. That has the consequence that the head piece 11 moves between the first position and the second position.

(18) According to FIG. 5, the adjusting element 19 is at a spacing I.sub.1 from the drive 30, and the head piece 11 is in the first position to form a certain angle between the link 15 and the head piece 11. According to FIG. 6, a spacing I.sub.2 exists between the adjusting element 19 and the drive 30, and the adjusting element 19 is moved further toward the end 21 and the head piece 11 is in an intermediate position between the first position and the second position. According to FIG. 7, the adjusting element 19 is in the end 21, a spacing I.sub.3 between the adjusting element 19 and the drive 30 is set, and the head piece 11 is in the second position.

(19) In addition, relative movement between the head piece 11 and the four-bar linkage 14 is arrestable by the adjusting element 19, because it prevents relative movement in its rest position. In the present embodiment, the adjuster 36 is subject to a self-locking, so that the adjusting element cannot be moved unintentionally. Here, it prevents movement of the four-bar linkage 14.