GB2219493A

GB2219493A - Vehicle furniture anchorages

Info

Publication number: GB2219493A
Application number: GB8813877A
Authority: GB
Inventors: Cecil Norman Unwin
Original assignee: UNWIN C N LTDS; CN Unwin Ltd
Current assignee: UNWIN C N LTDS; Braunability UK Ltd
Priority date: 1988-06-11
Filing date: 1988-06-11
Publication date: 1989-12-13
Also published as: GB2219493B; GB8813877D0

Abstract

A floor track (1) has an inverted T-section channel whose mouth, defined by flanges (2), has periodic enlargements between slots (4). A seat or other furniture is fixed to a bar (6) which overlies the track and which carries a member (8) with headed studs (9) on its underside and a spring loaded plunger (10). The studs (9) can enter the track channel through the enlargements (3) and, when shifted longitudinally, they become captive below the flanges (2). The plunger (10) can then engage in one of the enlargements. The member (8) has limited freedom of movement with respect to the bar (6), to allow for irregularities in track and/or furniture, and a clamping device (20, 22) mounted on the bar (6) can be actuated to urge the member (8) upwards and the bar (6) downwards, clamping the heads of the studs (9) against the undersides of the flanges (2). <IMAGE>

Description

"Improvements relating to Furniture Anchorages" This invention relates to furniture anchorages, particularly for seats. It is concerned with those of the kind in which parallel ground or floor rails each provide an undercut formation with which clamping or locking elements at the base of the seat can cooperate, these elements being movable between an offering-up attitude or position to one in which they positively secure the seat to the rails by engagement with the undercut formations, and a catch device engageable with one of the rails to prevent movement of said elements when the latter are in said positively securing positions. Such an anchorage will be referred to as 'of the kind described'.

Although reference is made primarily to seats, it will be understood that the invention is intended to embrace other fittings, such as tables, bunks or stretchers (in ambulances).

These anchorages are commonly used in aircraft and other vehicles where the seating plan may need to be altered from time to time. Aircraft seats are made to a very high specification, with a rigid frame that makes it an efficient system. However, other seats, such as those for buses or ambulances, are not made to such high standards, and particularly when taken out and replaced later, it. is quite often found that they have twisted out of shape and proper engagement with the rails becomes difficult and occasionally impossible. Yet further snags are that the floor in which the rails are set may not be completely true and flat, the rails may be installed with the locking detents slightly out of step, or the rails may be slightly skew.

The aim of this invention is therefore to provide a more reliable clamping system for removable seats, without resorting to massive clearances to solve the inaccuracy problems.

According to the present invention there is provided an anchorage of the kind described wherein at least one said clamping or locking element is carried by a first member with limited freedom of movement with respect to a second member to which the seat is rigidly attached, there being means for mutually clamping said members together.

Generally, there will be two rails, and while this arrangement could be provided for both sides of the seat, it may be sufficient to have it just on one side and to have conventional rail engagement on the other side.

Conveniently the clamping means is a cam or wedging device, and it may have a rotary action to lift the first member up, urging the locking elements hard against the undercut formations, while bearing down on the second member, which itself will bear down on the rail.

Preferably there are two or even more clamping or locking elements on said first member and the catch device may also be carried by that member.

Advantageously, it has a spring loaded plunger which snaps into a detent in the rail when said clamping or locking elements are in said positively securing position. The condition of this catch device may be arranged to be determined by feel, for the underside of a seat is usually dark or awkward to view.

Preferably, each rail will have a channel of inverted T-section, the mouth of the channel having periodic enlargements for entry of said clamping or locking elements in the offering-up position. These elements will have a profile corresponding to the channel so that, on longitudinal movement to the positively securing position, they become vertically captive by the inturned flanges forming the channel.

Conveniently, the catch device will be arranged to engage one of said enlargements when the clamping or locking elements are in said positively securing position.

The underside of the seat, or rather each second member to which it is secured, may be further provided with guide means which engage the mouth of the channel between said enlargements.

For a better understanding of the invention one embodiment will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a vertical longitudinal section of a seat locking device, Figure 2 is a section on the line II-II of Figure 1, and Figure 3 is a fragmentary perspective view of a floor rail.

A seat (not shown) is designed to be anchored to two parallel rails 1 (only one of which is shown) set in the floor. Each rail is of U-section with inwardly turned flanges 2 forming an inverted T-section channel. The flanges 2 will be flush with the floor but their inner edges are not straight; at regular intervals they have semi-circular cut-outs 3, those of opposite flanges registering with each other so that, in plan view, there is the appearance of a series of circular apertures interconnected by short slots 4.

The seat itself is secured at points 5 near the ends to two parallel bars 6, one at each side, which will overlie the rails 1. On the underside, each bar 6 has ribs 7 which fit closely within the slots 4 to keep those bars aligned with the rails 1. Also, over an intermediate portion at least, each bar 6 is formed as an inverted channel section member with slightly flared flanges, as best seen in Figure 2.

Within this channel section there is an elongate block 8 carrying on its underside inverted mushroom-like studs 9, spaced to register simultaneously with the cutouts 3 and pass down through them. They are profiled so that they can then move longitudinally of the rail channel.

Between the studs 9 there is a locking device which has a plunger 10 whose enlarged lower end slides in a vertical bore 11 through the block 8 and whose thinner stem slides in a tubular guide 12 screwed into the upper end of that bore. This guide extends freely up through a gap 13 in the top of the bar 6. The plunger 10 is biased downwardly proud of the bore 11 by a spring 14, but it can be held in a raised, non-projecting position by a turn-bar 15 fitted through its upper end. When lifted and turned transversly to the rail 1 this turnbar rests on the domed upper end of the guide 12, but when turned at right angles to this position, it registers with a slot 16, allowing the spring 14 to act and push the plunger down.

When the bar 6 is seated flat on the rail 1 with the studs 9 engaged in apertures 3, the locking device is primed by the turn-bar 15 being aligned with the slot 16. The spring 14 is now free to urge it downwardly, but initially the plunger 10 will be registered with a slot 4 between two of the circular apertures 3.

However, when the seat is pushed in the fore and aft direction by a distance corresponding to half that between adjacent apertures 3 the plunger will come into registry with one. It then shoots down, preventing further movement. At this stage, the stems of the studs 9 will be within slots 4 and the heads of those studs will be engaging under the flanges 2, preventing vertical escape. the seat is therefore secure. For adjustment of the seat, the plunger 10 is of course first released and held so by the turn-bar 15.

The block 8 is itself urged downwardly by springs 17 acting against the underside of the bar 6, but is supported by a collar 18 screwed on near the top of the guide 12. This is housed in a central recess 19 of a disk 20, a spring washer 21 acting between the underside of the collar 18 and the base of the recess 19. Cams or wedges 22 are at diametrically opposite points at the periphery of the disk, which can be rotated by a handle 23. In the position shown in Figure 2, with the handle 23 projecting transversely to the bar 6, these cams 22 lie on either side of the bar, so that the disk 20 bears on its upper surface. But when the handle 23 is turned to align with the bar 6, the cams 22 force the disk 20 upwards as they wedge up onto the top of the bar 6.

This in turn raises the guide 12 through its collar 18, and thus the block 8 and its studs 9. The latter will then firmly engage under the flanges 2 of the rail.

It will be appreciated that, by virtue of the springs 17 and 21, there is some latitude for tilting movement of the block 8 in any direction. Also, by virtue of the gap 13, the whole assembly of the block 8 and the locking cam can be shifted longitudinally of the bar 6, which may be necessary if the cut-outs 3 of one rail are out of step with those of the other. That gap 13 can also be wider than the guide 12, allowing lateral adjustment provided there is some tolerance between the collar 18 and the recess 19 and/or between the cams 22 and the bar 6 in the Figure 2 position.

As with the turn-bar 15, it is easy ~ to check visually or to feel when the handle 23 is in the locking position and the seat is safe.

The arrangement described may be on just one side of the seat or on both.

The rail illustrated is of one type in fairly common usage, mostly in aircraft. It will be understood that different rail patterns will require some modification to the anchorage devices which co-operate with them.

For example, another type of known floor rail has a series of discrete rectangular slots, and the engagement by an anchoring foot or shoe is under their ends. The system described can be similarly adapted, so that once a shoe is entered and drawn back (or pushed forwards) a plunger is allowed to shoot down and prevent reverse movement.

Claims

1. An anchorage of the kind described wherein at least one said clamping or locking element is carried by a first member with limited freedom of movement with respect to a second member to which the seat is rigidly attached, there being means for mutually clamping said members together.

2. An anchorage as claimed in Claim 1, wherein the clamping means is a cam or wedging device.

3. An anchorage as claimed in Claim 1 or 2, wherein the clamping means has a rotary action.

4. An anchorage as claimed in Claims 1, 2 or 3, wherein the clamping means, when actuated, lifts the first member up, urging the locking element up against the undercut formations while bearing down on the second member, which itself will bear down on the rail.

5. An anchorage as claimed in any preceding claim, wherein there are at least two clamping or locking elements on said first member.

6. An anchorage as claimed in any preceding claim, wherein the catch device is carried by said first member.

7. An anchorage as claimed in Claim 6, wherein the catch device has a spring loaded plunger which snaps into one of a series of detents in the rail when the or each said clamping or locking element is in said positively securing position.

8. An anchorage as claimed in any preceding claim, wherein the or each rail has a channel of inverted Tsection, the mouth of the channel having periodic enlargements for entry of said clamping or locking element in the offering-up position.

9. An anchorage as claimed in Claim 8, as appendant to Claim 7, wherein the detents are provided by said enlargements.

10. An anchorage as claimed in Claim 7, 8 or 9, wherein the or each clamping or locking element has a profile closely corresponding to the channel so that, on longitudinal movement to the positively securing position, it becomes vertically captive by the inturned flanges part-covering the channel.

11. An anchorage as claimed in Claim 8, 9 or 10, wherein the underside of the seat or the second member to which it is secured is further provided with guide means which engage the mouth of the channel between said enlargements.

12. An anchorage substantially as hereinbefore described with reference to the accompanying drawings.