FR3044270A1 - SYSTEM FOR MOUNTING A CONNECTING ROD OF A HEADREST ON A SEAT BACK OF A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a system (1) comprising a sheath (4) provided with a locking device (6) for the rod comprising: a collar (7); a latch (8) rotatably mounted on said collar, said latch comprising a notch edge (11) arranged to be inserted into a notch of the rod when arranged opposite, said latch comprising a lever arm (12) extending opposite said edge; a spring (13) mounted on said flange so as to actuate said edge towards said rod, so as to achieve its insertion into said notch when they are vis-à-vis; a sheathing cap (14) covering said collar, said cap being rotatably mounted on said collar, said cap comprising a stop (15) bearing on said arm so as to allow, by manual rotation of said cap, a rotation of said latch from its locking position to its unlocking position.

Description

The invention relates to a mounting system of a connecting rod of a headrest on a motor vehicle seat back and a seat comprising such a system.

It is known to provide a mounting system of a connecting rod of a headrest on a motor vehicle seatback, said system comprising: said rod intended to be integrally mounted to a headrest cushion said rod being provided with at least one locking notch, a sliding receiving sheath of said rod, said sheath being intended to be mounted at the top of said backrest, said sheath comprising a sliding sleeve of said rod and being provided with a device for locking said sliding rod.

The blocking of the sliding rod makes it possible to block the height of the headrest to maintain it in the selected adjustment position and / or to prevent its projection into the passenger compartment in the event of a collision of the vehicle.

Prior art embodiments have proposed unblocking the sliding of the rod by means of a manual rotation applied to a sheath cap mounted at the upper end of said sheath, such an arrangement making it possible to guarantee that the unlocking operation sliding is the result of a deliberate maneuver, the arrangements providing simply a translation, in particular by means of a push button, not allowing to guard against the risk of unintentional unlocking so effectively.

In such a context, it has been proposed in particular that the locking of the rod is done by inserting a portion of a spring wire into the notch, said portion forming a locking portion; said wire having a general U-shaped pin shape, the middle part of the U-shaped spring part and said locking part being formed by a branch end of the U; said spring being mounted on the sheath, said locking portion rotating about said middle portion to move from a locking position to an unlocking position.

In such an embodiment, it is difficult to give the blocking portion, in axial view, a geometry that allows it to cooperate optimally with the bottom of the notch while allowing its removal from said notch with a small amplitude rotation - allowing limit the force to be applied to unlocking - if not providing a significant dimension between the locking portion and the middle portion, the implementation of such a dimension resulting in an over-dimensioning of the locking device.

Therefore, in order to limit the size of the locking device, the known embodiments generally provide a blocking portion poorly adapted to the geometry of the bottom of the notch and results in a non-optimal blocking efficiency. The object of the invention is in particular to overcome this drawback. For this purpose, and according to a first aspect, the invention proposes a system for mounting a connecting rod of a headrest on a motor vehicle seatback, said system comprising: said rod to be mounted integrally with a headrest cushion, said rod being provided with at least one locking notch, a sliding receiving sheath of said rod, said sheath being intended to be mounted at the top of said backrest, said sheath comprising a sliding sleeve of said rod and being provided with a locking device of said sliding rod, said device comprising: • the upper end of said collar-shaped sleeve projecting radially from said sleeve, • a latch rotatably mounted on said flange along an axis of rotation substantially parallel to the central axis along which said rod extends, so that said latch can pass reversibly from a locking position at an unlocking position, said latch comprising a notch edge arranged to be inserted in locking position in said notch when they are arranged vis-a-vis, said latch comprising a lever arm s' extending opposite said edge relative to said axis of rotation, a spring mounted on said flange so as to actuate said edge towards said rod, so as to effect its insertion into said notch when they are opposite each other; A sheathing cap covering said flange, said cap being rotatably mounted on said flange along said median axis, said cap comprising an abutment bearing on said arm so as to allow, by manual rotation of said cap, a rotation of said flange; latch from its locking position to its unlocking position.

In this description, the terms of positioning in space (top, bottom, top, ...) are taken in reference to the system mounted in the vehicle.

The terms "diametrically", "radial", "axial", etc. are considered relative to the median axis that extends the stem.

With the proposed arrangement, the locking is done by inserting the latch in the notch, said latch being itself actuated by a spring which can be positioned, as will be seen later, in the immediate vicinity of the axis of rotation, which makes it possible to have a device for blocking small dimensions.

According to a second aspect, the invention proposes a seat comprising such a system. Other features and advantages of the invention will appear in the description which follows, made with reference to the appended figures, in which: FIG. 1 is a partial exploded perspective view of a sheath of a system according to one embodiment, FIG. 2 is a partial semi-exploded perspective view of the sheath of FIG. 1; FIG. 3 is a perspective view of the sheath of FIG. 1 completely assembled; FIGS. 4 are views in radial section. of the sheath of FIG. 1 during assembly of the sheath cap, in a first stage of initial angular positioning of the cap (4a), a second stage of rotation of said cap (4b) and a third stage of blocking 5 is a partial axial sectional view of a system comprising the sheath of FIG. 1, the latches being in the locked position, FIGS. 6 are partial views of FIG. t of the sheath of Figure 1, the latches being in the locking position (6a) and unlocking (6b).

Referring to the figures, there is described a system 1 for mounting a connecting rod 2 of a headrest on a motor vehicle seatback, said system comprising: said stem - issued in particular from a folded metal tube generally U-shaped returned, said rod being formed by a tab of the U-born to be integrally mounted to a headrest cushion, said rod being provided with at least one locking notch 3, • a sheath 4 of slidably receiving said rod, said sheath being intended to be mounted at the top of said backrest, said sheath comprising a sleeve 5 for sliding said rod and being provided with a locking device 6 for said sliding rod, said device comprising: The upper end of said collar-shaped sleeve radially projecting from said sleeve, a latch 8 rotatably mounted on said collar according to a substantially para rotation axis 9 it extends to the median axis 10 in which said rod extends, so that said latch can reversibly pass from a locking position to an unlocking position, said latch comprising a notching edge 11 arranged to be able to be inserted into locking position in said notch when they are arranged vis-a-vis, said latch comprising a lever arm 12 extending opposite said edge relative to said axis of rotation, • a spring 13 mounted on said collar so as to actuate said edge towards said rod, so as to effect its insertion into said notch when they are facing each other, • a sheath cap 14 covering said flange, said cap being rotatably mounted on said flange according to said middle axis, said cap comprising an abutment 15 - here in the form of a lug pointing downwards - bearing support on said arm so as to allow, by manual rotation of said cap, a rotational rotation; latch from its locking position to its unlocking position.

According to the embodiment shown, the notching edge 11 has a shape - here curved - allowing it to match the shape of the notch bottom 16 when the latch 8 is in the locking position. This provides an optimized crispness.

According to the embodiment shown, the spring 13 is in the form of a wire comprising a wound portion 17 spiral, said portion being mounted around the axis of rotation 9, which allows to have a minimized congestion blocking device .

According to the embodiment shown, the locking device 6 comprises two similar latches 8 actuated by respective springs 13, the sheath cap 14 comprising two respective stops for actuating each of said latches, the notch 3 being shaped so as to be able to receive simultaneously the notching edges 11 of said latches.

Such an arrangement makes it possible to benefit from a reinforced blocking.

According to the embodiment shown, the latches 8 are mounted diametrically opposite.

According to the embodiment shown, the notch 3 extends along the entire circumference of the rod 2, which allows to maintain the notch in case of rotation of said rod following application of a violent impact on the headrest.

According to the embodiment shown, the latches 8 are rotatably mounted on the flange 7 by rivets not shown.

According to the embodiment shown, the system also has the following characteristics: • the flange 7 is provided with upwardly pointing axial tabs 19, the free ends of said tabs being provided with projections 20 pointing radially outwards, The sheath cap 14 is provided with reciprocal projections 21 pointing inwards so as to cooperate with said projections to ensure the rotational mounting of said cap, the spacing between said projections is defined so as to be able to receive said reciprocal protrusions; during a first step of mounting said cap (FIG. 4a) preceding a second stage of assembly where said cap is rotated (FIG. 4b) in such a manner as to make said reciprocal projections and projections cooperate, said flange being provided with at least one non-return elastic pin 22 and in this case two pins 22 in the embodiment shown -prenant support end of at least one of said reciprocal projections to prevent a return of said cap, once it has been mounted (Figure 4c), in its position corresponding to said first step.

The elastic nature of the lug 22 allows its temporary retraction during assembly of the sheath cap 14.

Finally, not shown, a motor vehicle seat including at least one such mounting system 1, said system further comprising at least one locking device 6 mounted on the back of said seat.

Claims (9)

1. System (1) for mounting a rod (2) connecting a headrest to a motor vehicle seat back, said system comprising: said rod intended to be integrally mounted to a support cushion head, said rod being provided with at least one locking notch (3), a sheath (4) slidably receiving said rod, said sheath being intended to be mounted at the top of said backrest, said sheath comprising a sleeve (5) sliding said rod and being provided with a locking device (6) of said sliding rod, said system being characterized in that said locking device comprises: • the upper end of said shaped sleeve shaped flange (7) protruding radially from said sleeve, • a latch (8) rotatably mounted on said flange along an axis of rotation (9) substantially parallel to the median axis (10) along which said rod extends, so that said power latch e pass reversibly from a locking position to an unlocking position, said latch comprising a notch edge (11) arranged to be inserted in the locking position in said notch when they are arranged vis-à-vis, said latch comprising a lever arm (12) extending opposite said edge with respect to said axis of rotation, • a spring (13) mounted on said collar so as to actuate said edge towards said rod, so as to realize its insertion into said notch when they are in facing relation, • a sheathing cap (14) covering said flange, said cap being rotatably mounted on said flange along said median axis, said cap comprising an abutment (15) bearing on said arm so as to allow, by manual rotation of said cap, a rotation of said latch from its locking position to its unlocking position. 2. System according to claim 1, characterized in that the notch edge (11) has a shape, in particular curved, allowing it to match the shape of the notch (3) when the latch (8) is in the position of blocking. 3. System according to one of claims 1 or 2, characterized in that the spring (13) is in the form of wire comprising a wound portion (17) in spiral, said portion being mounted around the axis of rotation ( 9). 4. System according to any one of claims 1 to 3, characterized in that the locking device (6) comprises two latches (8) similar actuated by respective springs (13), the cladding cap (14) comprising two respective stops (15) for actuating each of said latches, the notch (3) being shaped so as to simultaneously receive the notch edges (11) of said latches. 5. System according to claim 4, characterized in that the latches (8) are mounted diametrically opposite. 6. System according to any one of claims 1 to 5, characterized in that the notch (3) extends along the entire circumference of the rod (2). 7. System according to any one of claims 1 to 6, characterized in that a latch (8) is rotatably mounted on the flange (7) by a rivet. 8. System according to any one of claims 1 to 7, characterized in that: • the flange (7) is provided with lugs (19) arranged peripherally at the periphery and pointing upwards, the free ends of said legs being provided with projections (20) pointing radially outwards, • the sheath cap (14) is provided with reciprocating projections (21) pointing inwards to cooperate with said projections (20) for rotational mounting of said cap The spacing between said protrusions is defined so as to be able to receive said reciprocal protrusions during a first step of mounting said cap preceding a second stage of the assembly, in which said cap is rotated in such a manner as to make said co-operation protrusions and reciprocal projections, • said flange is provided with at least one elastic lug (22) non-return bearing support end of at least one desdi reciprocal projections to prevent a return of said cap, once it has been mounted, in its position corresponding to said first step. 9. Motor vehicle seat comprising at least one mounting system according to any one of claims 1 to 8, said system comprising at least one locking device (6) mounted on the back of said seat.