Device for folding seat backrests in vehicles

The present invention relates to a device for sending down seat backrests in vehicles.

In the field of vehicles in general, and of vehicles for transporting passengers in particular, devices for sending down seat backrests are known, which are designed to enable the seats themselves to be set in a lowered position, in which the backrests lie on top of a respective seat, and which comprise, as is for example illustrated in the US patent No. US 3 966 253, two anchoring plates fixed to the vehicle or else to the seat itself, two supporting plates connected to a frame of the backrest itself and hinged to the anchoring plates, and a moving and blocking device, which is set between at least one anchoring plate and the corresponding supporting plate for moving the backrest between an upright position and the lowered position and for blocking the backrest itself in the upright position.

In the US patent mentioned above, the moving and blocking device comprises an actuation lever and a series of return plates, which are connected to one another and to the actuation lever itself to constrain the supporting plate to the anchoring plate and to release, under the action of the lever, the supporting plate from the anchoring plate, so enabling automatic moving of the backrest as a result of the elastic action of the springs.

The devices for sending down seat backrests of the type described above present a number of drawbacks basically due to their structure, which not only presents a high number of somewhat complex components and requires long production times, but also leads to the onset of mechanical play that can be experienced as unpleasant vibrations of the backrest.

The purpose of the present invention is to provide a device for sending down seat backrests in vehicles which will enable the drawbacks described above to be overcome in a simple and economically advantageous way.

According to the present invention, a device for sending down seat backrests in vehicles is provided, the backrests being manually mobile between two operative positions, and the device comprising: at least one anchoring plate fixed to a seat-cushion frame provided with a first guide slot; a supporting plate hinged to the anchoring plate and provided with a pin engaged in the first guide slot, the supporting plate being connected to a frame of the backrest; and blocking means fixed on the supporting plate for blocking the backrest itself at least in one first operative position of said two operative positions. The device for sending down seat backrests is characterized in that the blocking means comprise a second guide slot, which is engaged by the pin and can be superimposed on the first guide slot to enable free movement of the backrest, and a first blocking seat, which is set at a first end of the second guide slot in a position staggered with respect to the second guide slot itself and can be engaged by the pin with the backrest set in said first operative position.

The invention will now be described with reference to the annexed plate of drawings, which illustrate a nonlimiting example of embodiment thereof, and in which: <ul id="ul0001" list-style="dash" compact="compact"><li>Figure 1 is a side elevation of a preferred embodiment of a device for sending down seat backrests in vehicles made according to the present invention;</li><li>Figure 2 is a view at an enlarged scale of a detail of Figure 1;</li><li>Figure 3 is a front elevation of the item represented in Figure 2; and</li><li>Figure 4 is a top plan view of the device for sending down seat backrests illustrated in Figure 1.</li></ul>

With reference to Figures 1 and 4, number 1 designates, as a whole, a device for sending down seat backrests 2 in vehicles.

The backrest 2 can be rotated manually about a horizontal axis of rotation A between a raised operative position and a lowered operative position, and comprises a tubular frame 3, which is substantially shaped like a U set upside down and has two terminal portions 4 and two supporting plates 20, which are set in a transverse direction with respect to the axis A and are welded to the two terminal portions 4.

The device 1 comprises three anchoring plates 10, which have a bottom base 11 provided with through holes 12 for anchorage to a seat-cushion frame 100 mounted on the vehicle and associated to the backrest 2, and each of which is further provided with a respective guide slot 14 having a semicircular shape centred on the axis A. Of the three plates 10, one plate, designated by 10a, is set by itself on one side L1 of the backrest 2, whereas two plates, designated by 10b and 10c, are set on a side L2 of the backrest 2 opposite to the side L1 and, as is illustrated in greater detail in Figure 3, are assembled together by means of three spacers 15 arranged around the slot 14.

The three spacers 15 keep the two plates 10b and 10c facing one another and parallel to one another, with the corresponding slots 14 aligned with respect to one another, as well as at a given distance from one another so as to define a compartment 16 peripherally opened outwards.

According to one embodiment, which is not illustrated but may be readily inferred from what has been described above, and with the purpose of further reducing the costs of production of the device 1, the plate 10b can be directly integrated in the seat-cushion frame 100, or better still, in a side of the seat-cushion frame 100.

The two plates 20 are hinged to the corresponding plate 10a and 10b at the axis A and each is provided with a corresponding pin 21, which is set parallel to the axis A and is engaged so that it can slide in a transverse, direction with respect to the axis A through the corresponding slots 14. In particular, the pin 21 of the side L2 is engaged in both of the slots 14 of the plates 10b and 10c.

Hinging of the plates 20 in the plates 10b and 10c and simultaneous engagement of the pins 21 in the slots 14 enables guided and controlled moving of the backrest 2 about the axis A between the raised operative position and the lowered operative position.

According to what is better illustrated in Figure 2, the device 1 further comprises a blocking plate 30, which is set between the plates 10b and 10c and is mobile within the compartment 16 to co-operate with the plates 10b and 10c so as to block the backrest 2 in the two operative positions or at least in the raised operative position. In particular, the plate 30 is mounted so that it can turn about an axis B of oscillation parallel to the axis A and defined by the spacer 15 set on the opposite side of the slots 14 with respect to the base 11.

Finally, the device 1 comprises a control arm 31 fixed to the plate 30 for moving the plate 30 itself about the axis B, and a bending spring 40, which is carried by the plates 10c and 10b inside the compartment 16 and is set with a free end thereof up against the plate 30 so as to oppose any displacement of the plate 30 itself from a respective resting position, the purposes and functions of which will be described in greater detail in what follows.

According to what is illustrated in Figure 2, the plate 30 comprises an oscillation slot 32, set in the proximity of the control arm 31, and a corresponding guide slot 33, which is also engaged by the pin 21 and can be superimposed on the guide slots 14 of the plates 10b and 10c to enable free movement of the backrest 2 between the two corresponding operative positions.

The slot 32 determines the maximum limits of oscillation of the plate 30 and is engaged by a pin 32a, which is fixed and set transverse to the plates 10b and 10c and is set parallel to the axis A.

Also the slot 33 has a semicircular shape identical to that of the slot 14 and is provided, at its respective opposite ends, with two blocking seats 34a and 34b, which are set in respective positions staggered with respect to the slot 33 and can be engaged by the pin 21 with the backrest 2 arranged in the corresponding operative positions.

In particular, the seats 34a and 34b are set on opposite sides of the slot 33 and, whereas the seat 34b extends in a direction substantially parallel to the slot 32, the seat 34a is instead oriented substantially perpendicular to the slot 32 itself.

The staggered position of the seats 34a and 34b with respect to the slot 33 and the combination of the movement of oscillation of the plate 30 about the axis B with the countering force exerted by the spring 40 precisely against the plate 30 cause the pin 31 to be completely blocked inside the seats 34a and 34b when the backrest 2 is set in any of its operative positions. In addition, the constructional simplicity of the plates 10, 20, and 30 and the presence of the spring 40 prevent any vibration of the backrest 2 in so far as the staggering between the slots 33 and 14 not only brings about complete blocking of the pin 21 in the seats 34a and 34b, but also enables recovery of any play due to tolerances of fabrication or positioning.

In use, with the pin 21 set in the seat 34a, i.e., with the backrest 2 set in its raised operative position, it will be necessary to act manually on the lever 31 to displace the plate 30 from its own resting position so as to superimpose the slots 14 and 33 on one another.

At this point, it will be possible to send the backrest 2 down manually, causing the pin 22 to traverse both of the slots 14 and 33 until the pin 22 itself reaches a position corresponding to the seat 34b, inside which it will practically be pushed by the spring 40 which will produce a new misalignment of the slots 14 and 33.

A similar procedure must be followed to raise the backrest 2 from the lowered operative position to the raised operative position.

It is understood that the invention is not limited to the embodiment described and illustrated herein, which is to be considered merely as an example of embodiment of the device for sending down seat backrests in vehicles, it being instead possible for said device to undergo further modifications regarding shapes and arrangement of parts, and constructional and assembly details.