GB2202564A

GB2202564A - Collapsible post

Info

Publication number: GB2202564A
Application number: GB08706669A
Authority: GB
Inventors: Trevor Piggott
Original assignee: UK Lift Co Ltd
Current assignee: UK Lift Co Ltd
Priority date: 1987-03-20
Filing date: 1987-03-20
Publication date: 1988-09-28
Also published as: GB8706669D0

Abstract

The post comprises a base (1) and a column (11) resting on the base in upright position, the base being fixable to the ground and including a base seating (4) and a bottom anchorage (7), the column comprising a hollow shaft (12) having at its bottom end a shaft seating interengaged with the base seating and provided above the shaft seating with a top anchorage (14), the top and bottom anchorages being interconnected by resilient means (17) keeping the column in upright position on the base, allowing the column to be deflected from the upright position by the action of an external force and returning the column to the upright position when the external force ceases to act. <IMAGE>

Description

SAFETY POST The invention relates to a safety post for carrying e.g. a warning light, a warning sign, or a device for the formation of a photo-electric barrier.

If a vehicle collides with a conventional post, both the vehicle and post are damaged and often even the occupants of the vehicle are injured.

Posts are known which are attached to a base by snap-off screws, that are snapped off in collision so that both the vehicle and the post are damaged much less than would be the case with an ordinary post. However both the vehicle and post are still damaged and the screws are destroyed, so that the post must be repaired and freshly fixed in position using new screws. As a consequence, the post may be out of action for some time. Also known are easIly bendable posts, such as those used for slalom, but these are, for safety reasons, so easily bendable that they cannot car, any heavy objects on top. When deflected in collision, these posts do not return exactly to their initial position and may even be deflected by wind. They could not, therefore, be used for supporting means for the establishment of a.

photo-electric barrier.

The aim of the invention is to avoid, or at least to mitigate these disadvantages.

This is achieved according to the invention by a post having the features claimed in the claims.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a front view in section along line A-A in Fig. 2, of a safety post according to the invention; Figure 2 is a side view along line B-E in Fig. 1 of the same post; Figure 3 is a plan of the base shown in Figs 1 and 2; and Figure 4 is a side view of a post deflected in collision still in contact with the vehicle (not shown) that collided with it.

The illustrated safety post comprises a base 1 carrying a column 11. The base 1 comn,ises a base plate 2 which is rectangular and has in each corner a hole 3 for the fixing of the base plate 2 to a foundation (not shown) by anchor bolts (not shown).

In the centre of the base plate 2 is provided a seating 4 in the form of a square-shaped low wall inside which is situated a bottom anchorage 5 in the form of two lugs 6 carrying a pin 7 (e.g. a bolt) firmly fixed thereto. A roller (not shown) may be provided on the pin 7.

The column 11 is formed by a hollow shaft 12 of sausre-shaped cross-section carrying at its bottom end a hollow plinth 13 which is also of a square-shaped cross-section. The plinth 13 is so sized and shaped that it easily fits on to the seating 4 which means that it is slightly large in cross-section and also higher than the seating 4, so that its bottom surface firmly rests in use on the base plate 2. The shaft 12 is near its upper end provided with a top anchorage 13 formed by a pin 14 passing transversely through the shaft 12. The pin may carry a roller (not shown). In addition a clamp 15 is situa.ted at the upper end of the shaft 12, where there is also provided a flange 16 for the attachment of the object (not shown) to be carried by the post.

The column 11 is attached to the base 1 by an elastic rope 17 known per se. In the illustrated embodiment the elastic rope 17 has t one end a loop through which passes the pin 14 of the top anchorage 13. The rope 17 extends from the top anchorage 13 through the column 11, is trained around the pin 7 of the bottom anchorage 5, passes up through the column 11, is trained around the pin 14 of the top anchorage 13, passes down through the column 11, is trained around the pin 7 of the bottom anchorage 5 and passes up through the column 11 and is on top ma.nually pretensed to a desired degree and clamped in the pretensed state in the clamp 15. The top of the shaft 12 is then covered by a cover (not shown) or by the object (not shown) to be carried thereby.

Experiments with a prototype showed that if the rope 17 is sufficiently tensed the column 11 returns automatically to its initial upright position even if it is deflected ho-izontally. The column 11 need not have a plinth but may be of the same crosssection throughout. In that case the same limitations are placed on its cross-sectional shape and size as they are on the plinth 13. In a column with a plinth 13 no limitations as to the crosssectional shape are placed on the shaft 12. The cross-sectional shape of the plinth 13 must be the same as that of the seating d, except that the seating is slightly smaller as explained before.

Naturally the seating 4 need not be continuous, but may be interrupted if desired. So, for instance, the square-shaped seating 4 illustrated in Figure 3 could be interrupted in the middle of each of the sides if enough of the sides remains. If the column 11 must return accurately to its initial position without turning about its longitudinal axis (which is essential e.g. for the formation of a. photo-electric barrier) the plinth 13 should be in the shape of a regular polygon, preferably a square, hexagon or octagon; it may even be rectangular, particularly if used in conditions where it can be collided with from only one direction. If minor twisting is not important the plinth 13 may be circular. Depending on the size and weight of the column 11 and of the object carried thereby, the elastic rope 17 may be passed around the anchorages more or less times than shown. Also other elastic elements may be used instead of the rope, preferably elastic means the tension of which is adjustable. However, elastic rope has the advanta.ge that it is cheap, may be easily obtained and tensed, may be used for a post of any slze and is not susceptible to humidity and other harmful environmental influences.

Claims

1. A safety post comprising a base and a column resting on the base in upright position, the base being fixable to the ground and including a base seating and a bottom anchorage, the column comprising a hollow shaft having at its bottom end a shaft seating interengaged with the base seating and provided above the shaft seating with a top anchorage, the top and bottom anchorages being interconnected by resilient means keeping the column in upright position on the base, allowing the column to be deflected from the upright position by the action of an external force and returning the column to the upright position when the external force ceases to act.

2. A safety post according to Claim 1, wherein the base seating is slightly smaller that the shaft seating and is fully enclosed in the latter.

5. A safety post according to Claim 2, wherein the base seating and shaft seating are substantially in the shape of polygons or parts of polygons.

4. A safety post according to any one of the preceding claims, wherein the resilient means is formed by an elastic rope.

5. A safety post according to any one of the preceding claims, wherein the tension of the elastic means is adjustable.

6. A safety post according to any one of the preceding claims adapted for the attachment of at least one of object thereto.

7. A safety post according to Claim 1, constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.