- BACKGROUND OF THE INVENTION
The entire disclosure of DE 10 2005 014 897.2, which was filed Apr. 1, 2005, is incorporated herein by reference.
The present invention relates to a headrest system for a vehicle seat, in particular a motor vehicle seat, having a headrest bushing with a visible surface at an upper end, a headrest rod that can be inserted into the headrest bushing, a headrest arranged on the headrest rod, a first electrical contacting element assigned to the headrest bushing and a second electrical contacting element assigned to the headrest rod, between which an electrical contact can be established when the headrest rod is inserted.
- BRIEF SUMMARY OF SOME ASPECTS OF THE INVENTION
DE 297 19 937 U1 discloses a headrest system of the above-described type in which the headrest bushing, acting as a sliding guide, comprises a tube. The lower section of the tube is provided with slots for guiding the first contacting element. The upper section of the tube is not slotted, in order to form an upper stop. When the headrest rod is inserted, the electrical contact between the contacting elements is established.
An aspect of the present invention is the provision of improvements to a headrest system of the type mentioned above.
In accordance with one aspect of the present invention, a headrest system for a vehicle seat, in particular for a motor vehicle seat, includes at least one headrest bushing, which has a visible surface at an upper end, at least one headrest rod that can be inserted into the headrest bushing, a headrest arranged on the headrest rod, a first contacting element assigned to the headrest bushing and a second contacting element assigned to the headrest rod, between which an electrical contact can be established when the headrest rod is inserted. In accordance with this aspect, the headrest bushing includes a lower bushing and a separately formed upper bushing. The lower bushing carries (e.g., supports) the first contacting element, and the upper bushing includes (e.g., supports) the visible surface.
Because the headrest bushing comprises a lower bushing part supporting the first contacting element, and a separately formed upper bushing part supporting the visible surface, the two external functions that the headrest rod bushing has to perform, namely on the one hand to hide the entry point of the headrest rod bushing, and on the other hand to permit electrical connection of the first contacting element, can be assigned separately, one to each part respectively. Assembly in two stages is then also possible, in particular on the structure of the backrest of a vehicle seat. To start with, the lower bushing together with the necessary electrical contacts can be mounted, in particular before the upholstery is mounted to the backrest, and then the upper bushing together with the visible surface can be mounted, in particular after the upholstery has been mounted to the backrest.
To permit simple assembly, the lower bushing and/or the upper bushing is attached to the backrest structure preferably by way of a clip which becomes effective preferably after the lower bushing and/or the upper bushing have been partially inserted. The upper bushing itself may be inserted with positive engagement (contour fit (e.g., interference fit)) on or in the lower bushing, and an additional connection between the two parts may be possible.
The first contacting element is movably arranged preferably in the axial direction of the lower bushing, in particular it is pretensioned (e.g., biased) upwards in an axial direction by means of a spring in order to follow the movement of the headrest rod and maintain the contact with the second contacting element. To achieve defined motion, the first contacting element of the lower bushing is prevented from rotating preferably by the cooperative interaction between at least one guide projection and at least one lateral groove. Instead of the lateral groove, a slot may be provided. The contacting elements and any wire connected thereto are preferably insulated from the headrest bushing and the headrest rod to ensure, in the case of an ungrounded power supply and/or signal wires, that no short circuits occur and that otherwise a constant electrical contact is maintained.
The headrest system according to the invention may in principle be usefully fitted in all types of vehicle seat having an adjustable, electrically contacting headrest mounted to the backrest; in particular it may be used for vehicle seats having a removable headrest which may be stored elsewhere in the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects and advantages of the present invention will become apparent from the following.
The invention is described in more detail below with reference to an exemplary embodiment illustrated in the drawings, in which:
FIG. 1 schematically illustrates a longitudinal cross-section through a portion of the exemplary embodiment when the headrest rod is being inserted;
FIG. 2 is a corresponding view after electrical contact has been established;
FIG. 3 is a corresponding view depicting a mid-height adjustment;
FIG. 4 is a corresponding view depicting a low height adjustment;
FIG. 5 is a cross-sectional view of a portion of the exemplary embodiment, with the cross section taken along the line V-V in FIG. 1, and
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT
FIG. 6 is a schematic view of a vehicle seat.
A vehicle seat 1 for a motor vehicle has a backrest 3 on which is mounted a removable and height-adjustable headrest 6. The directional data mentioned below refer to the backrest 3 when it is appropriately aligned upright for sitting purposes. The headrest 6 comprises an electrically operated or triggered adjustment mechanism for normal use or for the event of a crash, so that electrical power supply wiring and/or signal wiring is provided. The adjustment mechanism of the headrest 6 can be conventional. The headrest 6 is part of a headrest system 11 having electrical contacts.
To support the headrest 6, the headrest system 11 comprises two hollow, preferably metal headrest rods 12, each of which can be respectively inserted into a headrest bushing 15 and can be secured in various positions by means of a detent system (not shown), such as a conventional detent system. Each headrest bushing 15 consists of a lower bushing 17 and an upper bushing 19. With the exception of some small deviations, each of the lower bushing 17 and the upper bushing 19 have a hollow cylindrical basic shape in order to accept the respective headrest rod 12. Each of the lower bushing 17 and the upper bushing 19 can be made of plastic. In the following, the longitudinal direction of the assembled headrest bushing 15 is designated as the axial direction.
The headrest bushing 15 is intended to be mounted at the upper end of the support structure 21 (e.g., frame) of the backrest 3, more precisely on a transverse member of the support structure. For this purpose, a clip 23 is formed at the upper end of the lower bushing 17 and just beneath it there is also formed a lower bushing flange 25. Prior to mounting the upholstery 22 to the backrest 3 (e.g., prior to mounting the upholstery to the support structure 21 so that the upholstery least partially covers the support structure), the lower bushing 17 is inserted from below into an opening in the support structure 21 until the lower bushing flange 25 comes to bear against the underside of a portion of the support structure and the clip 23 can engage over the portion of the support structure. More specifically and in accordance with the exemplary embodiment of the present invention, the lower bushing 17 is mounted to a portion of the support structure 21 of the backrest 3 by pushing the lower bushing flange 25 against one side of the portion of the support structure so that the clip 23 engages over the other side of the portion of the support structure.
At its upper end, the upper bushing 19 has an upper bushing flange 27 whose upward facing side is designed as a visible surface. After the upholstery 22 has been mounted to the backrest 3 (e.g., after mounting the upholstery 22 to the support structure 21 of the backrest in a conventional manner so that the support structure is at least partially covered with the upholstery), the upper bushing 19 is fitted from above into an opening in the upholstered backrest structure (which includes the support structure 21 and associated upholstery 22). The upper bushing 19 is fitted into this opening in the upholstered backrest structure typically until the upper bushing flange 27 comes bear against the upper side of/outer side of the upholstery 22. As a result, the lower surface of the upper bushing flange 27 is in opposing face-to-face contact with, and is thereby at least partially concealing, a portion of the outer side of the upholstery 22. At the same time, the lower end of the upper bushing 19 fits with positive engagement into the upper end of the lower bushing 17, such that there is an interference fit between the lower end of the upper bushing and the upper end of the lower bushing. As a result, each of the lower bushing 17 and the upper bushing 19 are mounted to the backrest, whereby the headrest bushing 15 is mounted to the backrest 3. An additional connection, for example another clip connection, may be provided between the lower bushing 17 and the upper bushing 19.
Within the lower bushing 17 there is arranged a first contacting element 31 that is generally in the form of a cylinder, except that the first contacting element further includes two radially extending guide projections 33. The guide projections 33 engage in axially oriented lateral grooves 35 in the inner wall of the lower bushing 17. The first contacting element 31 is axially movable over most of the length of the lower bushing 17, between an upper shoulder 37 and a lower shoulder 39 of the lower bushing 17. The guide projection 33 and the lateral grooves 35 prevent the first contacting element 31 from rotating relative to the lower bushing 17. A pressure spring 41, which is supported on the lower shoulder 39 or on a floor set therein, and which rests against the downward-oriented face of the first contacting element 31, pretensions (e.g., biases) the first contacting element 31 upwards against the upper shoulder 37. An at least single core, preferably double-core or multicore wire 43 of a power supply and/or signaling wiring system is led axially upwards to the first contacting element 31, and the cores of the wire each respectively terminate in a pin connector element 45 on the upward-pointing face of the first contacting element 31.
At its lower end, the headrest rod 12 comprises a second contacting element 50, the underside of which is designed as a connector socket that respectively accepts all the pin connector elements 45 of the first contacting element 31. An upper wire 52, which is identical to the first wire 43, is introduced into the headrest rod 12 from the headrest 6, and connected from above to the second contacting element 50. The contacting elements 31 and 50 and the wires 43 and 52 are electrically insulated from the headrest bushing 15 and the headrest rod 12.
During assembly, the headrest rods 12 are introduced axially into the respective headrest bushings 15. FIG. 1 shows the situation before the headrest rod 12 is fully mounted. The first contacting element 31 bears against the upper shoulder 37 and has no electrical contact with the second contacting element 50. The force of insertion and the direction of resulting movement are directed axially downwards. When the second contacting element 50 reaches the upper shoulder 37, as shown in FIG. 2, the pin connector elements 45 engage in the connector socket of the second contacting element 50, thereby establishing an electrical contact between the two contacting elements 31 and 50 and thus between the wires 43 and 52. The pressure spring 41 provides the necessary opposing force when the plugging-in occurs.
The electrical contact is established just before the headrest rod 12 reaches its highest detent position. As is shown in FIGS. 3 and 4, the headrest rod 12 may be moved to detent positions at various heights and thus the headrest 6 can be adjusted at various heights. The pressure spring 41 is compressed as the headrest 12 is introduced and supports the process of raising the headrest.
It will be understood by those skilled in the art that while the present invention has been discussed above with reference to an exemplary embodiment, various additions, modifications and changes can be made thereto without departing from the spirit and scope of the invention as set forth in the following claims.