GB2071756A - Pivoted Fitting for Seats - Google Patents

Abstract

The fitting comprises a bottom fitting part (1) and a top fitting part (2) interconnected by a pivot joint (3). The top fitting part is provided with a toothed segment (4) which cooperates with a toothed part (5) fixed to the bottom fitting part and operable by a handle (7) and means for automatically locking the fitting in case of shock. The bottom fitting part has arranged thereon a gear-wheel (8 Figure 2, not shown) which meshes with the toothed segment, is rotatable about a shaft (9, not shown) and carries at least one latching hook (16). Each hook is pivotable about a pivot shaft (15) arranged eccentrically on the shaft and loaded to an inwardly swung position by a spring (18). The bottom fitting part has arranged thereon a latching projection (19) the distance of which from the shaft is greater than the turning circle of the latching hook(s) in the inwardly swung position but smaller than the turning circle of the hook(s) in its outwardly swung position. In operation, should the hooks (16) swing outwardly into the position shown by the broken lines in Figure 1 under the influence of a rotational movement and of a centrifugal force resulting therefrom, their latching regions are latched on the projections (19) and the rotational movement is arrested. <IMAGE>

Description

SPECIFICATION Pivoted Fitting for Seats The invention relates to a pivoted fitting for seats, more especially motor vehicle seats, comprising a bottom fitting part which is fixed on the side of the seat section and a top fitting part which is connected to the said part by way of a pivotal joint and is associated with the back-rest, which top fitting part is provided with a toothed segment, which coacts with a coacting toothed part fixed on the bottom fitting part and capable of being actuated by means of a handle, and with an eccentric mass or weight, which automatically locks the pivotal fitting in the event of an impact or shock operating on the back-rest.

Such a pivotal fitting for the adjustment of the slope of the back-rest of a seat guarantees that the seat support is also securely held and substantially maintains its sloping position in the event that, during a driving accident, more especially a collision from behind, the handle is actuated and the pivotal fitting is consequently no longer locked by way of the toothed segment and coacting toothed section, such as is normally the case. Whereas a securing of the seat support against a forward swivelling movement is unnecessary with such an operational state of the pivotal fitting, since a passenger, with a frontal collision during driving, is forced into the safety belt, an automatic locking of the support in the opposite direction is necessary, since it is only the support which holds the passenger in the event of a collision from behind.

With the pivotal fitting of the type as previously mentioned and known from German Auslegeschrift 24 04 598, the eccentric weight is arranged on the connecting rod between the lefthand and the right-hand pivotal fittings of a seat.

With this known construction, the safety means actuated by the eccentric weight always responds when a sufficiently large acceleration is operative on the seat. In connection with seats which are arranged in motor vehicles, the acceleration which already occurs when the vehicle runs over a pot-hole or a hump is already sufficient to cause the response of the safety means. A passenger who wishes to adjust his seat support while the vehicle fortuitously travels over a pot-hole, accordingly finds himself prevented from adjusting the angle of slope and is given the impression that the pivotal fitting is defective. In addition, it is necessary to have a relatively large mass as the eccentric mass or weight, which is able to be brought into oscillation, depending on the travelling conditions.

It is the object of the invention to avoid the disadvantages of the known pivotal fitting and to provide such afitting which only locks automatically in the event of acceleration forces which are caused by an accident and which are operative on the seat-back, reliably produces the locking engagement and is light in weight.

This object is achieved by the fact that the bottom fitting part has arranged thereon a gearwheel which is rotatable about an axis or shaft and which meshes with the toothed segment, which gearwheel carries at least one arresting or latching hook which is pivotable about a pivot axis arranged eccentrically of the shaft and is loaded by a restoring spring in the inwardly swung or pivoted position, and that the bottom fitting part has arranged thereon at least one latching projection at a distance from the shaft or axis which is greater than the pivotal circle of the latching hook in the inwardly swung position, but is smaller than the pivotal circle of the latching hook in its outwardly swung position.

By means of the engagement of tooth segment and gear-wheel, the latching hook serving as a centrifugal weight is brought into a rotated position with the adjustment of the seat. If the adjustment of the seat support is effected too abruptly, the engaging hook swings outwardly under the action of the centrifugal force and is hooked on to the projection, so that the movement of the support is stopped. Due to the conversion into a rotational movement, only a small weight is required for the latching hook, so that the pivotal fitting is able, as a whole, to be of a light-weight construction and, as a consequence, energy is saved with the acceleration of the vehicle.Moreover, the arrangement according to the invention has no tendency to cause rattling, since the inertia forces which are operative on the latching hooks and which are caused, for example, by pot-holes, are small, because of the small mass of the latching hook and the restoring spring, which holds the latching hooks in the inwardly swung position, can be made with a relatively rigid construction.

The advantage of the invention thus consists more especially in that the force necessary for releasing the safety means is only produced with sufficiently rapid rotational movements, such as those which only occur with the acceleration of a passenger against the back-rest of the seat during a collision from behind. The normal, linear inertia forces which occur, for example, with a rough road surface, result in substantially smaller forces acting on the latching hooks, since there is no rotational movement.

The centrifugal forces can be increased by the gear-wheel being made relatively small and being connected coaxially with a disc which has a larger diameter than the gear-wheel and which carries the pivot spindle or shaft of the engaging hook in its marginal region. As a consequence, the difference between the centrifugal force and other linear inertia forces is further increased, so that the selective response of the safety means is improved. At the same time, the centrifugal weight mass of the latching hooks can be reduced and the spring force of the retaining springs can be increased, so as to assist a light-weight construction and to avoid rattling effects.

Furthermore, it is proposed that at least one stop member limiting the outward swinging movement of the latching hook is fixed on the bottom fitting part at an angle offset from the latching projection, which stop member is at a greater distance from the axis than the latching projection.

The stop member limits the outward swinging movement of the latching hook and, as a result ensures that the said hook is always brought into the best possibie engaging position with the projection at any centrifugal force which is above a threshold value.

If two latching hooks are arranged offset by 1800 on the gear-wheel, one engaging point for the restoring spring is saved, since the spring can be arranged horizontally on one diameter between two latching hooks. In addition, such an arrangement offers an improved degree of safety, since at least one of the latching hooks is swung out.

It is normally sufficient for the safety means of the pivotal fitting to be so constructed that it only responds with an impact against the front face of the back-rest, but not with an impact against the rear surface of the said back-rest. The arrangement according to the invention is however also suitable for an engagement in both pivotal directions of the said back-rest. A safety fitting, which also automatically arrests the backrest with a sudden impact against the rear surface is advantageous if, with a frontal collision, a passenger seated in the back seat of the motor vehicle is projected forwardly towards and against the back of the front seat.

Other developments of the invention will be apparent from the Claims.

Two constructional examples of the invention are hereinafter more fully explained and are described with reference to the accompanying diagrammatic drawings, in which: Figure 1 represents a side elevation of a pivotal fitting with a safety means, Figure 2 represents an assembly diagram of the safety means according to Figure 1, Figure 3 is a side elevation of another constructional example in respect of a pivotal fitting with a safety means, and Figure 4 is a section along the section line IV l\i in Figure 3.

With the safety pivotal fitting as shown in the Figures, a bottom fitting part 1, which is fixed on the seat, is pivotally connected by means of a support pivot 3 to a top fitting part 2 which is fixed on the back-rest of the seat. The top fitting part 2 terminates at the bottom end in a toothed segment 4 which, in the two constructional examples as illustrnted, extends over more than 1000. Meshing in this toothed segment 4 is a coacting toothed part 5, which is supported so as to be pivotable about a shaft or axle 6 on the bottom fitting part 1 and is capable of being brought by means of a handle 7 into and out of engagement with the toothed segment 4.

Meshing with the toothed segment 4 is a gearwheel 8, which is arranged on the bottom fitting part 1 so as to be rotatable about a shaft 9. In the constructional example according to Figures 1 and 2, this shaft is constructed as a shaft disc 9', whereas in the constructional example according to Figure 3 and 4, it is a stub shaft which changes into a square-section member 9".

As shown in Figure 2, the gearwheel 8 is made flat and is formed with two bores 10. These bores are in alignment with bores in the disc 9t, which is of a smaller diameter than the gear-wheel 8. The thickness of the disc 9' is greater than the thickness of the sheet-metal material of the bottom fitting part 1. The shaft disc 9' is mounted for rotatable movement in a circular recess 11 in the bottom fitting part 1. This recess is lined with a sliding ring 12, which is U-shaped in crosssection and engages over the edges of the recess.

It is made of Nylon or a similar material, which has the iowest possible friction with respect to the disc 9'. Its lateral surfaces, extending parallel to the fitting part 1, likewise contribute to reducing the friction.

In addition, the gearwheel 8 and the shaft disc 9' are connected to a disc 13, which likewise comprises bores which are in alignment with the bores 10 in the gear-wheel 8. Inserted through these bores which are in alignment with one another are two pins or studs 14, by which the parts 8, 9' and 13 are connected fast to one another and which project on the outer surface of the disc 13.

In its marginal zone, the disc 1 3 carries two stub shafts 15 which are offset by 1800 and on to each of which is fitted a latching hook 1 6. The stub shafts are the pivot axes of the latching hooks 1 6. Each latching hook is substantially the shape of an Arabic Figure 1, and is provided near one end with a bore 17, with which it engages over the associated stub shaft 1 5. The other end is formed as a latching zone and carries a hook which projects substantially at right-angles to the body of the hook. In the latching region, a restoring spring 18, which is formed as a helical spring, connects the two latching hooks 1 6. The spring 1 8 extends diametrally across the disc 1 3.

The forward ends of the pins or studs 14 serve as a stop for the latching hooks 1 6 in their inwardly swung position, which is represented in Figure 1.

Four projections or lugs 19 are so stamped out, concentrically of the recess 11, in the flat material of the bottom fitting part 1 that they project in the plane of the latching hooks 1 6. The spacing of said projections 1 9 from the axis of the gearwheel 8 is so great that the projections 1 9 do not obstruct a turning of the disc 1 3 with latching hooks 16, provided the said hooks 16 are in their inwardly swung position. Should the said hooks 1 6 swing outwardly into the position shown in broken lines in Figure 1, under the influence of a rotational movement and of a centrifugal force resulting therefrom and because of their mounting far outside the mass centre point, then their latching regions are latched on the projections 1 9 and, as a result, abruptly stop the rotational movement. Since the latching hooks 1 6 are connected fast to the disc 13 and also to the gear-wheel 8, the said wheel 8 blocks the further movement of the upper fitting part 2, i.e. the back of the seat.

In the constructional examples as illustrated, four latching projections 1 9 are provided in each case, which are arranged at equal angular distances and with equal spacing from said axis.

Provided between the said latching projections 1 9 are stop members 20, which are at a greater distance from said axis than the latching projections 1 9 and prevent the said latching hooks 1 6 from swinging out too far, as may be seen in Figure 1 by reference to that position of the hooks 1 6 as shown in broken lines.

In the constructional example according to Figures 3 and 4, the gearwheel 8 and the disc 13 are fitted and fixed on the square-section zone 9" of the shaft 9. Since the free ends of the pins 14 in this constructional example do not serve as stopping means, the latching hooks 1 6 are so constructed that they have an abutment surface 21, with which they bear one in the vicinity of the pivot shaft 1 5 of the other in the inwardly swung position. Four latching projections 1 9 are likewise provided; however, these are not symmetrical, as in the constructional example previously discussed, but make possible an automatic arresting of the safety means only with acceleration of a passenger against the front surface of the back-support. The latching projections 1 9 are formed on a ring 22, from the internal circle of which they project inwardly. The internal circle serves as a stop member 20.

The top fitting part 2 is arranged between the bottom fitting part 1 and a bearing plate 23, as can be seen from Figure 4. Arranged on the outside of this bearing plate is the safety means, which is covered by a cap 24, so that it may be easily examined.

So as to achieve a reliable engagement between a latching hook 1 6 and a latching projection 19, the latching region of the said hooks 16 lies in the direction of rotation of the gearwheel 8 behind the pivot axis 15, as shown in broken lines in Figure 1.

Claims (9)

Claims

1. Pivotal fitting for seats, more especially motor vehicle seats, comprising a bottom fitting part to be fixed to the side of the seat part, and a top fitting part to be fixed to the back-rest and connected to the bottom fitting part by means of a pivot joint, which top fitting part is provided with a toothed segment which coacts with a coacting toothed part fixed on the bottom fitting part and capable of being actuated by means of a handle and with an eccentric weight, which automatically locks the pivoted fitting with a shock or impact acting on the back-rest, wherein the bottom fitting part has arranged thereon a gearwheel which meshes with the toothed segment and which is rotatable about a shaft, which gear-wheel carries a latching hook which is pivotable about a pivot shaft arranged eccentrically of the shaft and is loaded to the inwardly swung position by a restoring spring, and wherein the bottom fitting part has arranged thereon a latching projection at a distance from the shaft, which distance is greater than the turning circle of the latching hook in the inwardly swung position, but is smaller than the turning circle of the said hook in its outwardly swung position.

2. Pivotal fitting according to Claim 1, wherein the gear-wheel is connected to a disc so as to be fast in rotation therewith, which disc has a larger diameter than the gearwheel and carries the pivotal shaft of the latching hook in its marginal zone.

3. Pivotal fitting according to Claim 1 or 2, wherein a stop member limiting the outward swinging movement of the latching hook is fixed on the bottom fitting part offset at an angle relative to the latching projection, which stop member is at a greater distance from the shaft than the latching projection.

4. Pivotal fitting according to any one of Claims 1 to 3, wherein the latching projection is constructed so as to hinge symmetrically in relation to a radius line starting from the shaft.

5. Pivotal fitting according to any one of Claims 1 to 4, wherein the gear-wheel has arranged thereon two said latching hooks each pivotal about one said pivot shaft, the pivot shafts of which are offset by about 1800 and the engaging zones of which are connected to one another by the spring.

6. Pivotal fitting according to any one of Claims 1 to 5, having four said latching projections arranged at equal angular spacings and connected fast to the bottom fitting part.

7. Pivotal fitting according to any one of Claims 1 to 6, wherein the or each latching hook has a latching zone, which with a powerful impact against the front surface of the seat, in the outward swinging direction is forward, and, in the direction of rotation of the gear-wheel is behind the pivot shaft.

8. Pivotal fitting for seats constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.

9. A vehicle seat including a pivotal fitting according to any one of Claims 1 to 8.

1 0. A vehicle including a seat according to Claim 9.