GB2293313A - Improvements in or relating to a safety arrangement for vehicle seating - Google Patents

Abstract

A safety arrangement provided in a motor vehicle is associated with the rear seat. The rear seat has a squab 1 in the back part 4. The back part is movable pivotally from a substantially upright operational position to a substantially horizontal position. A beam 10 extends transversely of the vehicle. The beam has, at each end thereof, a latching mechanism (20, 21) solely to secure the beam to the body of the vehicle. Latching means are provided to latch the seat back to the beam. The beam can only be unlatched from the body of the vehicle when the seat back is latched to the beam. <IMAGE>

Description

DESCRIPTION OF INVENTION "IMPROVEMENT8 IN OR RELATING TO A SAFETY ARRANGEMENT" THE PRESENT INVENTION relates to a safety arrangement and more particulary relates to a safety arrangement provided in a motor vehicle.

In a large proportion of countries it is now a legal requirement that the rear seat of a motor vehicle be provided with safety-belts for each passenger to travel on the rear seat. If the rear seat is to accommodate three passengers, then the rear seat must be provided with three safety-belts, although the belt for the centre seat need only be a lap belt.

It is has been proposed that the back of the rear seat of a motor vehicle should be capable of folding forwardly. If the back of the seat is of an integral construction, the whole of the back of the seat is folded forwardly at one time.

However, it has also been proposed that the back of the seat should be divided into two portions, each portion being foldable forwardly independently of the other. In a typical arrangement, the seat is divided into a "one-third" portion and a "two-third" portion.

The "one-third" portion corresponds substasntially to one seat and the "two-thirds" portion corresponds substantially to two seats.

Whilst it is relatively straightforward to mount retractor mechanisms and other anchor points for safety-belts on the side wall of the motor vehicle for the two passengers located on the sides of the seat, a difficulty exists in mounting the retractor reel for the passenger to occupy the central seat. Although the retractor could be mounted in the seat back, the seat back would have to have very substantial strength to be able to withstand the forces applied to the retractor under accident circumstances. It is, of course, necessary for the retractor to be able to withstand such forces, but also it is preferable that when the seat back has been folded downwardly, the retractor and the associated belt are not positioned inconveniently.

The present invention seeks to provide an improved safety arrangement.

According to this invention there is provided a safety arrangement provided in a motor vehicle, the safety arrangement comprising a rear seat, the rear seat having a squab and a back part, the back part being movable pivotally from a substantially upright operational position to a substantially horizontal folded position, there being a beam extending transversely of the vehicle, the beam having, at each end thereof, a latching mechanism serving to secure the beam to the body of the vehicle, there being means for latching the seat back to the beam, the arrangement being such that the beam can only be unlatched from the body of the vehicle when the seat back is latched to the beam.

The seat back may be unitary, but preferably the seat back is divided into two parts, the arrangement being such that both parts of the seat back must be latched to the beam before the beam can be unlatched from the body of the vehicle.

Preferably the seat back, or one part of the seat back, carries a retractor for a safety-belt, means being provided for latching the retractor to the beam when the seat back, or the said part of the seat back, is in the operational position.

Conveniently each latching mechanism to secure the beam to the body of the motor vehicle comprises a latching arm carrying a latching lug, the latching arm being movable between a latching position and a release position, the latching mechanism being adapted to co-operate with a securing member secured to the body of tiie vehicle, the securing member presenting an element adapted to co-operate with the latching lug.

Advantageously the said element is in the form of an apertured plate, the plate being adapted to be inserted into a housing containing the latching mechanism against a bias from a spring-biassed ejector, which ejector occupies an initial position, before the plate is inserted into the housing, in which the ejector retains the latching arm in the release position.

Preferably the latching arm is associated with means to spring-bias the arm towards the latching position, the latching arm being actuated by a slider carrying an element which in one position of the slider, when the latching arm is in the latching condition, engages part of the latching arm to prevent the latching arm moving away from the latching condition and which, on sliding movement of an actuating slider, engages a cam face to move the latching arm pivotally to the release position.

Conveniently one latching mechanism is associated with a manually actuable latch adapted to latch the seat back, or part of the seat back, to the beam, the manually actuable latch only being actuable to release the seat back, or the part of the seat back, when the latch latching the beam is in the latched position, the latch latching the seat back or the part of the seat back serving to block movement of the latch latching the beam to the release position when the latch latching the seat back or part of the seat back is in the unlatched position.

Preferably the manually operable latch comprises a slidable element carrying locking means adapted to engage a tongue carried by the seat back, the slidable element being adapted to slide from an initial position in which the locking means engage the tongue on the seat back to a position in which the locking means are disengaged from the tongue, the slidable element carrying means which, to prevent disengagement of the manually operable latch, engage part of the latching mechanism latching the beam if an attempt is made to move the slidable element to release the tongue on the seat when the beam has been unlatched.

Conveniently the slidable element carries a blocking element which, when the slidable means has been moved to a position in which the tongue on the seat back, or part of the seat back, has been released, prevents actuation of the latch latching the beam.

In one embodiment the seat back, or part of the seat back, carries a tongue, the tongue being receivable within a passage forming part of a said latching mechanism, the passage being associated with means movable from an initial position, in which said means do not engage the tongue, to a final position in which the means engage the tongue and retain the tongue within the passage, said means being movable to the final position in response to movement of part of the latching mechanism latching the beam when the latching mechanism latching the beam is moved to the unlatched condition, the housing further defining an element which is resiliently biassed to a position which prevents actuation of the latching mechanism latching the beam to the released condition unless the tongue associated with the seat back, or part of the seat back, has been inserted into the housing to move said element against a bias.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a perspective view of the rear seat of a motor vehicle incorporating a safety arrangement in accordance with the invention, with the seat in the operative position, FIGURE 2 corresponding to Figure 1 showing the same seat with one part of the seat folded downwardly, FIGURE 3 is a view similar to Figure 2 showing the seat with two parts of the seat folded downwardly, a mounting beam being retained in an elevated position, FIGURE 4 is a view corresponding to Figure 3 illustrating both parts of the seat folded downwardly, the mounting beam being connected to the backs of the seats, FIGURE 5 is an exploded view of the mounting beam, FIGURE 6 is a sectional view illustrating a retractor mounted on one part of the seat as connected to the mounting beam, FIGURE 7 is a sectional view illustrating the essential operative components of a latch provided on the beam to latch the beam to the body or chassis of the motor vehicle, the latch being shown in the unlatched condition, FIGURE 8 is a view corresponding to Figure 7 showing the latch in the latched condition, FIGURE 9 is a perspective view of a latch mechanism incorporating the latch of Figures 7 and 8, the latch being shown in the unlatched condition of Figure 7, FIGURE 10 is a figure corresponding to Figure 9 showing the latch in the latched condition of Figure 8, FIGURE 11 is a vertical sectional view illustrating essential components of the latch in the position of Figure 9, FIGURE 12 is a view corresponding to Figure 11 showing the latch in a latched condition similar to that of Figure 10.

FIGURE 13 is a top plan view of a further latch mechanism incorporating the latch of Figures 7 and 8 showing the latch in the latched condition, FIGURE 14 is a view corresponding to Figure 13 showing the latch in the released position, FIGURE 15 is a further plan view showing the latch of Figures 13 and 14, with the view being taken at a different plane, FIGURE 16 is a view corresponding to Figure 16 showing the latch in a different condition, FIGURE 17 is a schematic view of the latch of Figures 13 to 16 illustrating the latch in the condition of Figure 13, FIGURE 18 is a view corresponding to Figure 17 showing the latch in the condition of Figure 14, and FIGURE 19 is a view corresponding to Figures 17 and 18 showing the latch in the condition of Figure 16.

Referring initially to Figure 1, the rear seat of a motor vehicle is illustrated. The seat comprises a seat squab 1 and a back 2, the back being made up of a first part 3 equivalent to one-third of the back and being made up of second part 4 equivalent to two-thirds of the back.

Incorporated in the back 2 of the seat are a plurality of buckles 5 adapted to receive tongues 6 provided on safety belts 7. Each safety-belt is associated with a retractor.

Two retractors 8 are provided located adjacent the opposed sides of the seat. These retractors may be mounted directly on the body or chassis of the motor vehicle. A further retractor 9 is provided, associated with a safety-belt 7, intended for use by a person sitting in the centre of the seat. The retractor 9, as will be described later, is secured to a transverse beam 10. The transverse beam 10 extends horizontally substantially adjacent the top of the back 2 of the seat.

As will be described in greater detail hereinafter, the transverse beam 10 is provided with two latch mechanisms, the latch mechanisms being located at each of the two opposed ends of the beam. Each latch mechanism serves to latch the beam to the chassis or body of the vehicle. Also, each latch mechanism is engaged by a tongue present on one of the two back parts 3 or 4 of the seat.

When the seat part 3 is in the elevated position it is connected to the beam by one of the two latch mechanisms.

When the seat part 4 is in the elevated position it is connected to the beam by a fastening means associated with the retractor reel 9, and also by the other of the two latch mechanisms.

Thus, in an initial condition, as illustrated in Figure 1, the beam 10 is latched to the body of the motor vehicle and both of the seat back parts 3 and 4 are latched to the beam.

By actuating a seat back release button 11, the seat back part 3 may be released and may be folded downwardly to occupy the position illustrated in Figure 2. Thus the seat part 3 is unlatched from the beam and is folded downwardly. As can be seen, part of the squab 1 of the seat is also folded upwardly at this time.

Alternatively, the seat part 4 might be folded downwardly (again part of the seat squab 1 would be folded upwardly at this time). The part 4 of the seat back may be folded downwardly whenever the seat-belt 7 has been fully retracted within the retractor 9 and a retractor release button 12 (see Figure 2) has been activated.

It is to be appreciated that starting from the condition illustrated in Figure 1, it is also possible to fold both the seat back part 3 and the seat back part 4 downwardly simultaneously if the seat back release button 11 and the retractor release button 12 are both activated. The seat will then occupy the position illustrated in Figure 3. The beam 10 remains in its initial position.

However, it is to be appreciated that a further option, when the seat is in the condition of Figure 1, is to activate a centrally located beam latch button 13, thus releasing the latches provided at each end of the beam and disconnecting the beam from the body of the motor vehicle. The beam then remains secured to the backs of the seat portions 3 and 4 which can be folded downwardly to occupy the position illustrated in Figure 4.

As will become clear from the following description, the various latches are mechanically inter-connected so that the beam 10 cannot be disconnected from the vehicle on operation of the beam latch button 13 unless both of the seat back portions 3 and 4 are latched in position in contact with the beam. In other words, if either the seat back part 3 is folded down or if the seat back part 4 is folded down, or if both the seat back parts 3 and 4 are folded down, it is not possible to operate the latches to disconnect the beam from the body of the motor vehicle. Thus, the beam 10 is always either latched to the body of the vehicle or latched to the seat back portions 3 and 4, (or latched both to the vehicle body and to the seat backs). Thus, the beam 10 cannot be removed from the vehicle.

Figure 5 is a diagrammatic view of the beam 10. The beam 10 is provided with a first latch mechanism 20 provided at one end of the beam and a second similar (but different) latch mechanism 21 provided at the other end of the beam. The beam is provided with a reinforced substantially central region 22 which is located to receive the retractor mechanism 9. A "T"-shaped anchoring element 23 is provided which is bolted or otherwise secured in position within the region 22.

The retractor 9 can be connected to this element 23.

It is to be observed that the beam latch button 13 is associated with two Bowden cables 24 which extend to the latch mechanisms 20 and 21.

Figure 6 illustrates the retractor 9 mounted at the top of the seat back part 4. The retractor 9 is adapted to be the JreJ to the reinforced region 22 of the beam when the seat part 4 is in the upright position. The retractor 9 is retained in position by means of a latch 25. The latch 25 is associated with a latch release button 12. Thus, before the seat part 4 can be folded downwardly, the retractor release button 12 must be activated, releasing the latch 25, and thus permitting the seat part 4, together with the retractor reel 9, to be folded downwardly.

Figures 7 and 8 illustrate the essential components within a latch which is present in the latching mechanism 20 or 21.

The latch is contained within a housing 30 adapted to be secured to the end of the beam. The housing 30 defines a passage 31 adapted to receive part of a securing member 32.

The securing member 32 comprises a lower substantially circular lug 33 provided with a central aperture 34 adapted to receive a bolt by means of which the securing member 32 may be mounted to the body of the motor vehicle. The securing member defines a substantially horizontally extending passage 35 for a purpose that will become clear hereinafter.

Above the passage 35 two spaced apart vertical plates 36 support between them a top element 37 in the form of a plate having a substantially central aperture 38. It is the top element 37 that is adapted to be received within the passage 31 of the housing.

Contained within the passage 31 is an ejector member 39 associated with a spring 40. The ejector is thus a spring biassed ejector adapted to bias the top element 37 out of the housing 30.

The ejector, when in the forwardly biassed position as illustrated in Figure 7 rests on top of a latching lug 41 which is formed as an integral part of a latching arm 42. The latching arm 42 is pivoted about a pivot pin 43. The latching arm 42 is spring biassed to rotate in an anti-clockwise direction about the pivot pin 43 by a spring 44. The latching arm 42 defines a depending cam finger 45 located beneath the latching lug 41. The cam finger 45 defines an upper inclined cam face. A depending stop 46 is also provided located beneath the latching lug 41, spaced above the cam face of the cam finger 45.

A slider 50 is provided adapted to be moved against the bias of a spring 51 by means of a Bowden cable 52. The slider carries a transverse pin 53 which passes through a guide slot 54. The transverse pin 53 extends between the cam face defined on the cam finger 45 and the rest of the latching arm 42.

The housing carries a protruding shank 60 having an enlarged end 62 adapted to pass through the passage 35. The housing and the mounting support 32 each carry pads 63,64 of resilient material.

The top of the housing 30 is provided with a pivoting indicator lever 65 having an integral spring 66 biassing the lever downwardly and a depending lug 67. The indicator lever 65 carries an indicating end 68 adapted to be received within an open cowl 69. The inner part of the cowl carries a warning label which is usually visible, but which is obscured by the indicating end of the lever 65.

When the described latch is in the initial position illustrated in Figure , the unlatched position, the slider 50 is biassed to the right by means of the spring 51, and the transverse pin 53 is moved into engagement with the stop 46.

The latching arm 42 is prevented from pivoting counterclockwise about the pivot axis 43 by virtue of the fact that the ejector 39 is located within the slot 31 above the locking lug 41. The indicator lever is biassed downwardly exposing the warning label with the cowl 69.

If the housing 30 is moved towards the right as shown in Figure 7, as a consequence of movement of the beam 10 in the appropriate direction, the top element 37 of the securing member 32 will be introduced into the slot 31 and the ejector 39 will be moved towards the eFt , thus compressing the spring 40. Simultaneously the shank 60 with the enlarged head 62 will pass through the passage 35.

When the top element 37 has been introduced into the slot 31 by such an extent that the aperture 38 is aligned with the latching lug 41, the latching arm 42 will pivot about the pivot point 43 under the influence of spring 44, thus moving the latching lug into the aperture 38. The top element 37 is thus securely retained within the latch. The slider 50 will then move towards the right under the effect of the spring 51 moving the transverse pin to a position immediately underneath the stop 46.

As the latching arm 42 moves upwardly, the latching lug 41 engages the depending lug 67 present on the indicator arm 65 moving the indicator arm 65 upwardly against the bias provided by the spring 66. The indicating end 68 of the indicating arm 65 thus moves to a position in which it is visible in the cowl from the exterior of the housing, thus obscuring the warning label.

When the latch is in this position, as illustrated in Figure 8, the latch is prevented from unlatching readily since the transverse pin is located beneath the stop 46, thus preventing any clockwise pivotal movement of the latching arm 42.

It is to be appreciated that if the motor vehicle in which the safety arrangement is provided is involved in an accident, there will almost inevitably be some distortion of the beam 10, thus mis-aligning the shank 60 and the passage 35. The enlarged head 62 of the shank 60 will thus engage the end of the mounting arm 32, defining the passage 35, preventing the mounting support 32 from being disengaged from the described latch if the latch is inadvertently released.

In order to release the latch the Bowden cable 52 is actuated moving the slider 50 towards the left. The transverse pin 53 engages the upper cam face defined by the cam finger 45, and as the pin moves along the guide slot 54, the engagement of the pin and the cam face defined by the cam finger 45 causes the latching arm 42 to pivot in a clockwise direction about the pivot point 43 re-compressing the spring 44. The latching lug 41 thus moves out of the aperture 38 provided in the top element 37, and the ejector 39 ejects the top element 37 under the influence of the spring 40. As the ejector plate 39 moves forwardly it reoccupies the position illustrated in Figure 7, with part of the ejector lying over the latching lug 41, thus retaining the latching arm 42 in the position in which the spring 44 is compressed.The indicating arm 65 moves back to its initial position under the influence of the integral spring finger 66.

When the tension in the Bowden cable is released, the slider 50 moves towards the right under the influence of the spring 51 until the transverse pin 53 engages the stop 6.

The latch is now again in the condition illustrated in Figure 7.

The latch mechanism as shown in Figures 7 and 8 is, in the described embodiment of the invention, associated with means which serve to interlock the latch so that the latch can only be released, thus releasing the beam from the main body of the motor vehicle, when both the seat backs are in the upright and latched condition.

As mentioned above, there are two latch mechanisms 20 and 21 and the two latch mechanisms are slightly different, although each incorporates the basic latch illustrated in Figures 7 and 8. Each of the latch mechanisms 20 and 21 includes a slightly different inter-lock mechanism to prevent inappropriate unlatching of the latch.

Figures 9 to 12 illustrate, in a simple manner, the basic latch components and an associated inter-lock which actually serves to secure the seat back portion 3 in position.

Referring to Figures 9 to 12, the locking arm 42 and the ejector 39 as described above can be seen, together with the associated spring 40. In Figure 10 the apertured top element 37 is also visible since, in that figure, the latch is in the latched condition.

The Bowden cable 52, and the spring 51 are shown, and the slider 50 is also visible.

The seat release button 11 is formed integrally with a sliding plate 70 having a protruding tongue 71 adapted to be received in a notch 72 provided in the ejector 39 when the ejector 39 is in an appropriate position. Depending from the sliding plate 70 is a locking and blocking member 73. The locking and blocking member 73, as can be seen most clearly in Figure 11, comprises a central shaft 74 which extends from the plate 70 and the associated projecting tongue 71, and which carries, at its lower end, beneath the projecting tongue 71 a projecting blocking finger 75. On the other side of the depending shaft 74 are two locking projections 76,77.

The described components are intended to co-operate with a locking tongue 78 which is mounted on the rear of the seat part 3, the tongue 78 defining a central aperture 79. The tongue 78 is intended to be moved into the described mechanism along a predetermined path defined by an appropriate passageway (not shown). A spring biassed tongue ejector 80 is provided adapted to eject the tongue 79 from the described mechanism when the tongue is released.

As shown in Figures 9 and 11, the sliding plate 70 is in a left-hand most position and serves to lock the tongue 78 in position. The central locking projection 76 passes through the aperture 79 formed in the tongue 78. The blocking finger 75 is not present in the path followed by the slider 50, and thus the slider 50 is free to move. In Figure 9, tension has been applied to the Bowden cable, compressing the spring 51, releasing the latch mechanism primarily illustrated in Figures 7 and 8 so that the ejector 39 is moved to a forward position (equivalent to the position of Figure 7). It can be seen that with the ejector in this position, the tongue 71 is not aligned with the recess 72 meaning that the sliding pate 70 cannot slide. Thus, the seat tongue 78 is securely retained within the latching mechanism and cannot be released.

However, when the latching mechanism of Figures 7 and 8 is in the latched condition, as shown in Figure 10, the notch 72 is aligned with the tongue 71, meaning that the sliding plate 70 can slide towards the right as shown in Figure 10. When the sliding plate las slid towards the right to occupy the position shown in Figure 12, it can be seen that the locking projection 76 is withdrawn from the central aperture 79 in the tongue 78 meaning that the spring biassed ejector 80 may eject the tongue 78 from the latching mechanism. Thus, in other words, the seat back part 3 is disconnected from the latch. The ejector 80 moves forwardly to occupy a position (as can be seen from Figure 12) adjacent the free end of the locking projection 76, thus preventing the sliding pate 70 from sliding towards the left as shown in the illustrations.It can be seen that the blocking finger 75 is now located in the path of the slider 50, thus preventing the slider 50 from moving even if tension is applied to the Bowden cable.

This means that with the seat back released from the described latching arrangement, the latching mechanism primarily illustrated in Figures 7 and 8 cannot be activated to release the beam.

Figures 13 to 19 illustrate the latch mechanism associated with the seat part 4, that is to say the two-thirds seat part.

This latch mechanism again incorporates the basic latch illustrated in Figures 7 and 8, and components which cooperate with a tongue present on the seat part 4, providing an inter-lock effect. However, there is no seat release button equivalent to the button 11.

Referring initially to Figures 13 and 14 a tongue 90 having a central aperture 91 is provided on the seat back, and positioned to be inserted into a channel 92 formed within a housing 93, one wall of the housing 93 at the level of the section of Figures 13 and 14 forms a resiliently deformable finger 94 having an inwardly directed terminal portion 95, but in the position illustrated in Figure 13, the tongue 90 is free to be moved into and out of the channel 92.

The 2; is illustrated and can be seen to carry a camming projection 9j located adjacent the resilient finger 94. The ejector 39 is movable axially relative to the pivotal latching arm 42.

As can be seen from Figure 14, when the ejector 39 moves forwardly, when the main latching mechanism as shown in Figures 7 and 8 is unlatched, the camming portion 96 engages the resilient arm 94 moving the locking end portion 95 into a position within the central aperture 91 formed in the tongue 90, thus preventing the tongue 90 from being moved out of the slot 92. Thus, when the main latching mechanism of Figures 7 and 8 is unlatched, the tongue 90 cannot be moved out of the channel 92, thus preventing the seat back portion 4 from moving away from the beam.

Referring now to Figures 15 and 16 which serve to illustrate the arrangement in the region of the slider 50, it can be seen that part of the housing 93, at this level, defines a resilient finger 97 which extends from one side of the housing, remote from the slider 50, across the channel 92, through an aperture 98 formed in the wall of the housing adjacent the slider, and terminates in a projecting portion 99. When the tongue 90 is inserted in the channel 92, the tongue tends to move the resilient arm 97 to the position illustrated in Figure 15 in which the projecting end 99 is spaced from the slider 50, thus permitting movement of the slider 50. Thus when the tongue 90 is in the position, a slider 50 can be activated to release the main latching mechanism of Figures 7 and 8.However, as can be seen from Figure 16 when the tongue 90 is removed from the channel 92, the resilient arm 97 moves to its "natural" position with the projecting end 99 serving to block movement of the slider 50.

Figures 17 to 19 further illustrate the latching mechanism of Figures 13 to 16.

It is thus to be appreciated that the latch of the latch mechanism 20 and the latch of the latch mechanism 21 cannot be operated to release the beam from the securing members 32 unless the tongues 78 and 90 are both in position within the latching mechanisms, that is to say unless both of the seat backs 3 and 4 are in the elevated position and are latched to the beam. With the seat backs in this specific position, the latches of the latch mechanisms 20 and 21 may be activated to release the beam from the body of the motor vehicle but, of course, the beam will be secured to the seat back portions 3 and 4.

Claims (13)

CLAIMS:

1. A safety arrangement provided in a motor vehicle, the safety arrangement comprising a rear seat, the rear seat having a squab and a back part, the back part being movable pivotally from a substantially upright operational position to a substantially horizontal folded position, there being a beam extending transversely of the vehicle, the beam having, at each end thereof, a latching mechanism serving to secure the beam to the body of the vehicle, there being means for latching the seat back to the beam, the arrangement being such that the beam can only be unlatched from the body of the vehicle when the seat back is latched to the beam.

2. An arrangement according to Claim 1 wherein the seat back is unitary.

3. An arrangement according to Claim 1 wherein the seat back is divided into two parts, the arrangement being such that both parts of the seat back must be latched to the beam before the beam can be unlatched from the body of the vehicle.

4. An arrangement according to any one of the preceding Claims wherein the seat back, or one part of the seat back, carries a retractor for a safety-belt, means being provided for latching the retractor to the beam when the seat back, or the said part of the seat back, is in the operational position.

5. An arrangement according to any one of the preceding Claims wherein each latching mechanism to secure the beam to the body of the motor vehicle comprises a latching arm carrying a latching lug, the latching arm being movable between a latching position and a release position, the latching mechanism being adapted to co-operate with a securing member secured to the body of the vehicle, the securing member presenting an element adapted to co-operate with the latching lug.

6. An arrangement according to Claim 5 wherein the said element is in the form of an apertured plate, the plate being adapted to be inserted into a housing containing the latching mechanism against a bias from a spring-biassed ejector, which ejector occupies an initial position, before the plate is inserted into the housing, in which the ejector retains the latching arm in the release position.

7. An arrangement according to Claim 6 wherein the latching arm is associated with means to spring-bias the arm towards the latching position, the latching arm being actuated by a slider carrying an element which in one position of the slider, when the latching arm is in the latching condition, engages part of the latching arm to prevent the latching arm moving away from the latching condition and which, on sliding movement of an actuating slider, engages a cam face to move the latching arm pivotally to the release position.

8. An arrangement according to any one of the preceding Claims wherein one latching mechanism is associated with a manually actuable latch adapted to latch the seat back, or part of the seat back, to the beam, the manually actuable latch only being actuable to release the seat back, or the part of the seat back, when the latch latching the beam is in the latched position, the latch latching the seat back or the part of the seat back serving to block movement of the latch latching the beam to the release position when the latch latching the seat back or part of the seat back is in the unlatched position.

9. An arrangement according to Claim 8 wherein the manually operable latch comprises a slidable element carrying locking means adapted to engage a tongue carried by the seat back, the slidable element being adapted to slide from an initial position in which the locking means engage the tongue on the seat back to a position in which the locking means are disengaged from the tongue, the slidable element carrying means which, to prevent disengagement of the manually operable latch, engage part of the latching mechanism latching the beam if an attempt is made to move the slidable element to release the tongue on the seat when the beam has been unlatched.

10. An arrangement according to Claim 9 wherein the slidable element carries a blocking element which, when the slidable means has been moved to a position in which the tongue on the seat back, or part of the seat back, has been released, prevents actuation of the latch latching the beam.

11. An arrangement according to any one of Claims 1 to 9 wherein the seat back, or part of the seat back, carries a tongue, the tongue being receivable within a passage forming part of a said latching mechanism, the passage being associated with means movable from an initial position, in which said means do not engage the tongue, to a final position in which the means engage the tongue and retain the tongue within the passage, said means being movable to the final position in response to movement of part of the latching mechanism latching the beam when the latching mechanism latching the beam is moved to the unlatched condition, the housing further defining an element which is resiliently biassed to a position which prevents actuation of the latching mechanism latching the beam to the released condition unless the tongue associated with the seat back, or part of the seat back, has been inserted into the housing to move said element against a bias.

12. A safety arrangement substantially as herein described with reference to and as shown in the accompanying drawings.

13. Any novel feature or combination of features disclosed herein.