DE29814461U1 - Seat underframe of a motor vehicle seat - Google Patents

Description

Applicant: C. Rob. Hammerstein GmbH & Co. KG, Merscheiderstraße 167, 42699 Solingen

Designation: Seat base of a motor vehicle seat

The invention relates to a seat base of a motor vehicle seat according to the preamble of claim 1.

Motor vehicle seats of this type are always equipped with a safety belt. As things stand, this consists of a lap belt and a shoulder belt. Both come together in a V-shape in a plug-in part that can be inserted into a belt buckle. The other end of the lap belt is preferably attached to the motor vehicle seat itself. The other end of the shoulder belt is usually attached to the body, but in a so-called integral belt seat it can also be held in the backrest.

In motor vehicle seats, there is an increasing trend to provide a height adjustment of the seat support in relation to the longitudinal adjustment device, which consists of two pairs of rails. In the seat base of the type mentioned above, the height adjustment device has rear rockers, i.e. a left and a right rear rocker. They support the seat support in its rear area. The seat support must also be supported in its front area. Rockers, i.e. front rockers, can also be provided for this purpose, but other devices are also possible, for example curved guides for axle pins on the front edge of the seat, etc.

Seat bases must be very safe, in particular the seat belt must be anchored to them in such a way that the entire vehicle seat can withstand the loads during the prescribed tests. The design of the seat base should also be such that it has the lowest possible total weight and is easy to

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can be assembled and installed and can also be easily recycled. The fastening points for the safety belt, in particular the lap belt, should therefore be designed and arranged in such a way that the arrangement is on the one hand favorable for use and on the other hand the components into which the forces caused by an accident are introduced can absorb these forces well without becoming too heavy due to excessive dimensions.

This is where the invention comes in. Its task is to further develop the seat base of the type mentioned above so that a safety belt, in particular the lap belt of a safety belt, is both positioned in a way that is favorable for a user and can absorb the high forces that arise in the event of an accident if the individual parts are sensibly dimensioned.

Starting from the seat base of the type mentioned at the beginning, this task is solved in that a fastening area for the lap belt of the safety belt is provided on the swing arm of the seat rail of the pair of rails on the outside of the vehicle, which is located between the two swing joints of this swing arm and which is closer to the upper swing joint than to the lower swing joint.

According to the invention, the free end of the lap belt is therefore intercepted on the swing arm on the outside of the vehicle. A fastening area is provided there, where the said end of the lap belt is arranged. This fastening area is not located on the seat support or on the seat rail, but within a defined position of the rear swing arm. As a result, on the one hand, the fastening area changes only slightly when the height of the seat support is adjusted, in any case significantly less than when the belt end is fixed to the seat rail. On the other hand, however, the forces to be introduced are such that the individual parts of the seat base that play a role in the transmission of accident-related forces, in particular the rear swing arm, can be dimensioned normally. Since the end of the lap belt does not engage at the very top, i.e. in the upper swing arm joint, the lifting conditions are still favorable and the rear swing arm can deform under the effect of forces caused by an accident, its strength can be fully utilized without the seat support and a cross member connecting the two swing arms at the top having to be made unnecessarily strong.

The invention therefore teaches a particularly favorable arrangement of the free end area of the lap belt. It represents a happy compromise between an arrangement that is easy to use and an arrangement that is favorable in terms of strength.

The fastening area is usually designed as a hole. A bolt is inserted through this hole, for example, to which the free, suitably designed end of the lap belt is connected; for example, the bolt passes through the free end.

In a preferred embodiment, the fastening area is provided on a bulge that is designed in such a way that it bulges outwards on the vehicle side. A bend is particularly suitable here. The bulge makes the path of the lap belt more favorable; it essentially only runs downwards from the seat and in any case does not run with a component towards the middle of the seat. The bulge also ensures sufficient free space during movements when adjusting the height.

In a particularly preferred embodiment, the fastening area for the free end of the lap belt is located at a distance from the upper swing arm joint that is less than a third of the distance between the two swing arm joints. The closer the fastening area is to the upper swing arm joint, the more precisely the free end of the belt is guided when the height adjustment device is adjusted, but the greater the load on the rear swing arm and the other parts in the event of an accident. The position specified has proven to be a particularly favorable solution.

Furthermore, it is preferred to bend the swing arm on the outside of the vehicle towards the middle of the vehicle so that the upper swing arm joint is significantly closer to the middle of the vehicle than the lower swing arm joint. The difference here is several centimeters, e.g. 2 to 5 cm. In this way, it is possible to arrange the pair of rails on the outside of the vehicle so far outwards that it is actually no longer directly under the seat. This results in more legroom. In addition, the lap belt is positioned more favorably. Furthermore, the rails on the outside of the vehicle are

pair attached in an area of the floor assembly where greater strength is present.

The common middle section of the seat belt, on which even higher tensile forces usually occur in an accident than on the free end of the lap belt considered so far, can be intercepted directly on the seat rail. For this purpose, it is advantageously proposed that the belt buckle be attached directly to the seat rail of the pair of rails in the middle of the vehicle. In this case, an attachment using an L-shaped bracket is particularly suitable. One leg of this bracket is connected to the seat rail, and the belt buckle is arranged on the other. With this design, in the event of acceleration forces caused by an accident, essentially only the pair of rails and the L-shaped bracket are loaded.

The belt buckle can also be arranged on the swing arm in the middle of the vehicle. This has the advantage that, depending on the position of the belt buckle along this swing arm, the belt buckle follows the movements of the seat support more or less when the height is adjusted. It is possible to arrange the belt buckle in an upper area of the swing arm in the middle of the vehicle, as is the case with the swing arm on the outside of the vehicle for the end of the lap belt. Here, too, the advantages already described apply. On the one hand, the belt buckle remains in the correct position for easy operation, essentially independent of the settings of the height adjustment device. On the other hand, the forces to be transmitted can still be controlled in the event of accident-related loads.

Preferably, the swing arm in the middle of the vehicle has a smaller lateral offset towards the center of the seat or towards the center of the vehicle than the swing arm on the outside of the vehicle. This allows the seat to be better fitted into the existing space between a tunnel in the middle of the vehicle and the side sills of the floor assembly.

Further advantages and features of the invention emerge from the remaining claims and the following description of non-limiting embodiments, which are explained in more detail with reference to the drawing. In this drawing:

FIG. 1: a perspective view of a seat base, which is next to

the height adjustment of the seat support, which is designed here with front swing arms, also allows a height adjustment of the front edge of the seat,

FIG. 2: a top view of the seat base according to Figure 1, FIG. 3: a sectional view along the section line III-III in Figure 2, FIG. 4: a view along the line IV-IV in Figure 2 and

FIG. 5: a perspective view of a seat base similar to Figure 1, but now with a belt buckle that can be attached to the seat support.

First, the seat base frame according to Figures 1 to 4 will be discussed. The seat base frame according to Figure 5 is essentially the same as this first embodiment. Therefore, only the essential differences compared to the first embodiment will be highlighted. In this respect, the following description also applies to the majority of the seat base frame according to Figure 5, insofar as there are similarities.

The seat base frame includes a pair of rails 20 in the middle of the vehicle and a pair of rails 22 on the outside of the vehicle. If you want to avoid reference to the installation in the motor vehicle, you can also refer to the pair of rails in the middle of the vehicle as the first pair of rails and the pair of rails on the outside of the vehicle as the second pair of rails. Both pairs of rails 20, 22 each have a seat rail 24 or 26. Articulated areas for articulated connections with swing arms 28 to 34 are formed on this, namely a rear swing arm 28 on the outside of the vehicle, a rear swing arm 30 in the middle of the vehicle, both of which together as a rear swing arm carry a seat support 36 in its rear area. Furthermore, front swing arms 32 and 34. On each seat side, the respective seat rail 24 or 26, the two swing arms 28, 32 or 30, 34 and seat support 36 form a four-bar linkage of a parallelogram arrangement. Both parallelogram arrangements on each seat side move synchronously because the front swing arms 32, 34 are connected by a cross member 38, and the rear swing arms 28, 30 are rigidly connected to one another by a cross tube 40. The

Each steering square is assigned an adjustment device of a known type (not shown here) which takes over the adjustment and locking of a joint.

The floor rails of the two pairs of rails 20, 22 are attached to a floor assembly 42. A tunnel 44 is indicated, as it usually runs along the longitudinal center of a passenger car. This also makes the allocation of the pairs of rails 20, 22 etc. to the center of the vehicle clear.

The seat support 36 is connected to a frame 46, which forms the front edge of the seat, at two opposite joint areas that form an axis line running parallel to the cross member 38 or the cross tube 40. It extends forwards in a U-shape. The angular position of this frame 46 relative to the seat support 36 can be changed by means of an electric motor 48 and a downstream gear. This influences the height of a front edge 50 and thus, in the finished vehicle seat, the front edge of the seat.

A V-shaped safety belt is shown in Figure 1. It has a lap belt 52 and a shoulder belt 54, which merge into one another in a known manner at a common plug-in part 56 on the middle side of the vehicle. This plug-in part is assigned a belt buckle 58, which is attached to a leg of an L-shaped angle 60 that projects upwards and thus away from the floor assembly 42. The second leg of this angle 60 runs parallel to the floor assembly 42 and is rigidly connected to the seat rail 24.

The other end of the lap belt 52 is permanently fixed in a fastening area 62, which according to the invention is located on the rear swing arm 28 on the outside of the vehicle and is designed as a hole. This fastening area 62 is located between an upper hinge axis 64 and a lower hinge axis 66. It is significantly closer to the upper hinge axis 64 than to the lower hinge axis 66. In the embodiment according to Figure 1, it is located approximately one third of the distance between the two hinge axes 64, 66 from the upper hinge axis 64.

The rear, vehicle-outside swing arm 28 is angled several times. The place where the upper joint axis 64 passes through the swing arm 28

is offset by about 3 to 4 cm from the location where the lower joint axis 66 passes through. As a result, the pair of rails 22 on the outside of the vehicle is essentially no longer perpendicular below the seat support 36 and its frame 46, as can be seen in particular from Figure 3. The rear swing arm 28 runs around the fastening area 62 in a radial plane to the two mutually parallel joint axes 64, 66, as a result of which a bolt or screw that is inserted through the fastening area 62 designed as a hole runs parallel to the joint axes 64, 66. The swing arm 28 is a stamped sheet metal part.

The front, outside-side swing arm 32 is also angled towards the center of the seat, as can be seen in particular from Figure 2. In contrast, the rear, center-side swing arm 30 is only slightly angled, the offset is close to 0, typically 1 cm. As a result, the center-side rail pair 20 is essentially below the seat support 36, as shown for example in Figure 2 or Figure 4. The offset is towards the outside of the seat, i.e. towards the center of the vehicle.

From Figures 3 and 4 it can be seen that both seat rails 24, 26 are each made up of two individual profiles. One profile, namely the partial profile that is closer to the other seat rail, is angled several times, while the outer partial profile has a simpler profile shape that can be described as a crutch or J-shaped. In this way, the tensile force is introduced directly into the rear wings 28 and 30. In other words, the hooking line is essentially in the line of pull of the lap belt 52.

In the embodiment according to Figure 5, the L-shaped angle 60 has been omitted. The belt buckle 58 is now hinged to an axis 68, which is formed by a pivoting part 70. This has a second axis 72, with which it is hinged to the seat support 36. The pivoting part 70 has an engagement area that is opposite a toothed arch 74, which is formed on a recess in the rear swing arm 30 on the inside of the vehicle.

When the belt buckle 58 is pulled in the direction shown (see arrow), the pivoting part 70 is pivoted and thereby comes into engagement with the toothed arch 74, whereby further movement is blocked. In this way

it is possible to arrange the belt buckle 58 on the seat support 36 so that it is easily accessible. When the height of the seat support 36 is adjusted, it moves with it.

Finally, Figure 5 shows a projection 76 on the otherwise identically constructed rear swing arm 28 on the outside of the vehicle. This is designed and shaped in such a way that in the maximum permissible swivel position of this swing arm 28 towards the front, i.e. towards the front swing arm 32, it comes into contact with the surface of the seat rail 26 and thereby prevents further swiveling of the swing arm 28 in the specified direction.

Claims (7)

PROTECTION CLAIMS - with a pair of rails in the middle of the vehicle and a pair of rails on the outside of the vehicle (20, 22), which are arranged parallel to one another and laterally spaced from one another and which each consist of a floor rail and a seat rail (24, 26), the seat rail (24, 26) being guided so as to be longitudinally displaceable relative to the floor rail, - with two rear rockers (28, 30) of a height adjustment device, wherein each pair of rails (20, 22) is assigned a rocker and the respective rocker is articulated with its lower end region in a lower rocker joint on the seat rail (24, 26), - with a seat support (36) which is supported in its rear region by the two swing arms (28, 30) and is connected in each case in an upper swing arm joint to the upper end region of the swing arms, and - with a belt buckle (58) of a safety belt (52, 54) which is directly or indirectly connected to the seat rail (24) of the vehicle-central rail pair (20), characterized in that a fastening area (62) for the lap belt (52) of the safety belt (52, 54) is provided on the swing arm (28) of the seat rail (26) of the pair of rails (22) on the outside of the vehicle, which fastening area is located between the two swing arm joints of this swing arm (28) and is closer to the upper swing arm joint than to the lower swing arm joint. 2. Seat base according to claim 1, characterized in that the rocker (28) on the outside of the vehicle has a bulge, in particular a crank, directed towards the outside of the vehicle for the fastening area (62) with the lap belt (52). 3. Seat base according to claim 1, characterized in that the fastening area (62) for the lap belt (52) is located at a distance from the upper swing joint that is less than one third of the distance between the two swing joints. 4. Seat base according to claim 1, characterized in that the rocker (28) on the outside of the vehicle is bent towards the vehicle center (tunnel 44) in such a way that the upper swing joint is closer to the vehicle center than the lower swivel joint, in particular that the difference is 2 to 5 cm. 5. Seat base according to claim 1, characterized in that the belt buckle (58) is fastened directly to the seat rail (24) of the vehicle-central rail pair (20), in particular by means of an L-shaped angle (60) connected with one leg to the seat rail (24) and with the other leg to the belt buckle. 6. Seat base according to claim 5, characterized in that the belt buckle (58) is connected to the rear swing arm (30) in the middle of the vehicle, in particular that it is fastened in a connection area that is located between the middle of this swing arm (30) and the upper swing arm joint. 7. Seat base according to claim 4, characterized in that the vehicle-central swing arm (30) has a smaller lateral offset, which can also be 0, than the vehicle-outside swing arm (28), in particular that in the vehicle-central swing arm (30) the upper articulation point is offset by less than 1 cm compared to the lower articulation point towards the seat centre.