GB2035791A - Cross member for a vehicle seat - Google Patents

Abstract

A cross-member for connecting the longitudinal movable guides of a vehicle seat carrying an overturnable portion, which is formed by a metal tube 11 having flattened ends 12 for being welded onto the movable guides 1 and so shaped as to form themselves the members cooperating with a locking device on the overturnable structure of the seat. The central portion of the cross member is horizontally somewhat flattened and has a more ample curvature at its rear portion. The ends of the cross member are formed as hooks 13 or as projections 12a and can cooperate with locking devices movable around a longitudinal axis, as usual, or around a transverse axis. A remote control of the locking devices can be provided for. <IMAGE>

Description

SPECIFICATION Cross-member for the movable guides of the seat of a vehicle, tubular in shape and integrated with the seat locking device The present invention relates to the structure of the seats for vehicles, and more particularly to the cross member intended to connect to one another the two longitudinal movable guides of a seat, on which guides the structure of the seat is articulated, so as to allow the turnover of the seat, which seat may be fixed in its normal position by means of a locking device.

In the known constructions, the cross member connecting the movable guides is made of stamped plate having a substantially U-shaped cross-section. With this configuration it is possible to obtain a sufficient stiffness for the service requirements of the seat, but only a very poor torsional stiffness is obtained which is not sufficient to ensure the parallelism of the movable guides when the seat is separated from the stationary guides mounted on the floor of the vehicle. Difficulties arise therefrom during the assembly of the seat on the stationary guides, as well as possibilities of damaging the structure because of a deformation of the cross-member as long as the seat is separated from the stationary guides. Besides this, the cross-members made of stamped plate have sharp edges, with which the passengers' shoes may come into contact and be damaged.

Moreover, in the known constructions it is necessary to mount on the movable guides, or at least on one of them, a hook support arranged to cooperate with a locking device disposed on the overturnable structure of the seat to fix this latter in its normal position, allowing, on control, to release the seat for overturning it. This hook support constitutes an additional element which increases the number of components of the structure and the operations required for the assembly thereof, thus raising the cost of the industrial manufacture of the seat.

It is an object of the present invention to indicate a solution for the problem of obviating the disadvantages mentioned hereinabove, by providing a cross-member for the movable guides of a seat, which cross-member, with a substantially economical construction, will have a high stiffness also in a torsional direction, will be free from sharp edges susceptible of damaging shoes or other objects, and will assume also the functions of the hook support for the locking device, thus eliminating this support as separate element.

This object is attained according to the invention by the fact that the cross-member is formed by a metal tube section whose opposite ends are flattened for being welded onto the movable guides of the seat and are so shaped as to form themselves the members cooperating with the locking device installed on the overturnable structure of the seat.

In this way, the tubular cross-section ensures a high torsional stiffness, in spite of the presence of thin and, consequently, light weight walls, thus avoiding both the assembly difficulties and the possibilities of deformation as long as the seat is detached from the stationary guides. The absence of sharp edges avoids damaging of objects and also reduces the danger hook support and, consequently, the costs of production of such element and of its application.

to cooperate themselves with the locking device permits avoiding the assembly of a separate hook support and, consequently, the costs of production of such element and of its application.

Preferably, the tube which constitutes the cross-member is somewhat flattened in order to have its maximum resistance to flexural stress in the horizontal plane in which the highest stresses take place. Preferably also, this flattening is slightly convergent towards the front portion of the cross-member, which thus has a wider curvature at the rear side which is more subjected to coming into contact with the passengers' shoes or with other objects.

In one embodiment of the invention, the flattened ends of the cross-member are shaped as hooks, to cooperate with the usual locking devices used in these constructions. In another embodiment, instead, the flattened ends extend somewhat inside the movable guides of the seat to cooperate with especially provided locking devices coordinated with them, and as such pertaining to the present invention, which devices may be controlled directly like the usual devices, but are also particularly suitable for being controlled, through tie rods, by control elements located in a easily accessible position.

Two embodiments of the invention will now be described in detail, comparatively with an embodiment according to the prior art, with reference to the annexed diagrammatic drawings, in which: Figure 1 is a perspective view showing a section of the movable guide of a seat and the cross-member which connects the said guide to the other movable guide, as well as the locking device, in accordance with a prior art construction; Figure 2 is a perspective view of a first embodiment of the cross-member according to the present invention; Figures 3 and 4 are cross-sections along lines Ill-Ill and IV-IV of Fig. 2, respectively; Figure 5 shows one end of a cross-member according to another embodiment of the invention, applied to a section of a movable guide;; Figure 6 shows the parts of Fig. 5, in their cooperation with a locking device fitted to the overturnable structure of the seat; Figure 7 is another perspective view of the locking device shown in Fig. 6.

In the prior art embodiment shown in Fig.

1, each movable guide 1 of a seat, formed by a suitably shaped plate, is connected, by welding, to an end 2 of a cross-member 3 made of stamped plate, whose substantially U-shaped cross-section can be seen in Fig. 1.

Moreover, applied on the movable guide 1 is a hook support 4 apt to cooperate with the lower nose 5 of a rocking lever 6 pivoted on a horizontal axis 7 perpendicular to the crossmember 2, and pushed into engagement by the action of a spring 8. The axis 7 is supported by a support bracket 9 welded to a horizontal member 10 of the overturnable structure of the seat. The said member is represented by dot-and-dash lines in Fig. 1 in order to allow the vision of the parts lying behind, and for the same reason in the said Figure is not shown the rubber pad (as the one indicated by 14 in Fig. 6) normally mounted on the hook-shaped support 4 and serving for the noiseless support of the structure member 10 on the movable guide 1.

The arrangement described hereinabove has the disadvantages stated in the preamble of this description.

According to Fig. 2, the cross-member proposed by the present invention is formed by a metal tube section 11 which may be rectilinear or somewhat cambered and whose ends 1 2 are completely flattened, thus providing a surface adapted to be welded to a movable guide like the guide 1 shown in Fig. 1.

Beyond the region intended for the welding, at least on one side (and in the embodiment shown, on both sides), the cross-member continues with a portion 1 3 which, in addition to being flattened, is hook shaped and is suitable to directly cooperate with the lower nose 5 of a locking device like the device 5-9 shown in Fig. 1, mounted, obviously, facing the end of the cross-member 11. The rubber support pad may be disposed above the welded region 12 of the end of the cross-member 11, so as to be located near the locking device, as usual, or it may also be disposed in any other suitable location of the movable guide 1.

Preferably, the tube 11 forming the crossmember is flattened in oval form or, more preferably, with a taper towards the front portion, as shown in Fig. 3. In the presence of such dissimmetrical cross-section it may be suitable to provide the hook-shaped projections 13 on both ends of the cross-member 11, even if there is for each seat only one locking device and, consequently, only one hook 1 3 is utilized, because such configuration permits to standardize the manufacturing of the cross-members for seats whose locking device is disposed on the right-hand side or on the left-hand side. It is clear, however, that in the absence of such requirement one of the two hooks 1 3 may be omitted.

In the embodiment shown in Fig. 5, the cross-member 11 is provided with the flattened ends 12, but these ends do not terminate with hook-shaped portions 13; these flattened ends 1 2 comprise, instead, a portion 1 2a which freely projects inside the rest surface of the corresponding movable guide 1.

This portion 1 2a (which may also be only partially flattened or be part of the radiusing surface between the flattened portion and the not flattened portion of the cross-member) serves to cooperate with a locking device which is mounted on the structure element 10, but which, in the present case, cannot be of the usual type shown in Fig. 1, but must have a suitable configuration.

The locking device, shown in Figs. 6 and 7, comprises a lever 1 6 provided with a lower hooking nose 15, pivoted on an axis 17 and pushed towards the hooking position by a spring 1 8. The axis 1 7 traverses the element 10 of the overturnable structure of the seat, to which element also an end of the spring 1 8 is anchored, and is substantially horizontal and parallel to the cross-member 11. Lever 1 6 has a hole 1 9 for the anchorage of a cable 20 serving to remote-control the lever 16, in order to release the seat. The locking takes place automatically through the engagement of the nose 1 5 with the hooking portion 1 2a of the cross-member 11 when the seat is moved back to its normal position.

Obviously, the lever 16, in lieu of being remote-controlled by means of the cable 20, could also extend on the upper part into an element adapted to be controlled directly.

The rest pad 14 for the overturnable structure element is mounted, according to Fig. 6, in any point of the movable guide 1, but obviously it could also be disposed on the connection end 1 2 of the cross-member 11.

The shape and dimensions of the flattened ends 1 2 of the cross-member 11 intended to be welded to the movable guides 1, obviously depend upon the shape and dimensions of the guides themselves. The diameter and the wall thickness of the tube from which the crossmember 11 is obtained will be chosen as a function of the expected stresses, and the degree of flattening of the cross-member will be chosen as a function of the distribution of these stresses; in particular cases it may also be preferable to give to the cross-member a circular or a very little ovalized cross-section.

Furthermore, in accordance with the requirements of each application the cross-member 11 may be substantially rectilinear or more or less cambered.

These and other modifications may be made to what has been described and shown by way of example, without departing from the scope of the invention.

Claims (9)

1. A cross-member intended to connect to one another the two longitudinal movable guides of a vehicle seat, on which guides there is articulated the structure of an overturnable seat which may be fixed in its normal position by means of a locking device, characterized in that the cross-member is formed by a metal tube section whose opposite ends are flattened for being welded onto the movable guides of the seat and are so shaped as to form themselves the members cooperating with the locking device installed on the overturnable structure of the seat.

2. A cross-member as claimed in Claim 1, characterized in that the tube forming the cross-member is at least slightly flattened and has its larger dimension turned in an approximately horizontal direction.

3. A cross-member as claimed in Claim 2, characterized in that the flattening of the cross-member is asimmetrical, and the crossmember has a more ample curvature at its rear portion.

4. A cross-member as claimed in Claim 1, characterized in that it has a certain degree of camber.

5. A cross-member as claimed in one or more of the preceding Claims, characterized in that at least one of the flattened ends extends, beyond the region of connection to the movable guide, in a hook-shaped portion arranged to cooperate with the locking device, of a substantially usual type, installed on the overturnable structure of the seat.

6. A cross-member as claimed in Claim 5, characterized in that both of its ends are provided with a hook-shaped portion.

7. A cross-member as claimed in one or more of the preceding Claims, characterized in that it is provided, within the region of connection to at least one of the movable guides, with an at least partially flattened portion apt to cooperate with the locking device.

8. A cross-member as claimed in Claim 7, characterized in that the locking device is formed by a lever having a lower hooking nose and a return spring for moving it towards the hooking position, which lever is pivoted on a shaft mounted on an element of the overturnable structure of the seat, the axis of the said lever being substantially horizontal and parallel to the said cross-member.

9. A cross-member as claimed in Claims 8, characterized in that the lever of the hooking device is provided with means for hooking a remote-control cable.

1 0. A cross-member for connecting the longitudinal movable guides of a vehicle seat, substantially as hereinbefore described with reference to Figs. 2 to 4 or 5 to 7 of the appended drawings.