GB2192218A

GB2192218A - Collapsible barrier assembly

Info

Publication number: GB2192218A
Application number: GB08616337A
Authority: GB
Inventors: Peter D Cole; Michael D Ladlow
Original assignee: NAT RES DEV; National Research Development Corp UK
Current assignee: NAT RES DEV; National Research Development Corp UK
Priority date: 1986-07-04
Filing date: 1986-07-04
Publication date: 1988-01-06
Also published as: GB8616337D0

Abstract

A collapsible barrier assembly comprises a base member (10) which is fixed to the ground and presents a hollow and open-ended upright shaft (12), and a barrier unit including first (2) and second (3) limbs connected at a hinge (4) and each capable of sliding telescopically within the base member. When the first limb and hinge and part of the second limb all lie within the shaft, the remainder of the second limb projecting upwards out of it is held upright and so supports the barrier upright also. If the limbs are lifted so that the hinge comes clear of the shaft, the second limb and with it the barrier can pivot downwards to a collapsed condition in which the barrier rests on the ground. A pin- and-slot connection between the first limb and the shaft prevents the first limb escaping from the shaft, but allows the necessary telescopic motion between them that has already been described. <IMAGE>

Description

SPECIFICATION Improvements in or relating to collapsible barrier assemblies This invention relates to collapsible posts, railings and the like, which will be referred to in general as barrier assemblies. It relates in particular to movable safety railings of a kind frequently required around hazardous equipment.

Such railings must be robust and secure when erected, so as to prevent accidental access to and impacts with the equipment, but should also be simple to collapse so as to allow legitimate access when that is necessary. It is also most desirable that the railings when collapsed should still be secured and constrained by the same foundations on which they were previously erected: railings which can be completely separated from their foundations pose the two drawbacks that safe places have to be found where they can be stored while they are taken--down, and that they are sometimes not re-erected when they should be.

An example of one well-known type of collapsible barrier is to be found in UK Patent Specification- No. 1478840,-which describes a retractable post of the kind- by which private car-parkin-g bays are sometimes protected.

When collapsed, the post lies within an opentopped horizontal trough, recessed into the ground. At one end, the base of the trough is deepened to provide a small recess or well. A pin spans the trough just above the well, and passes through a short slot formed lengthwise in the post. To erect the post, the latter is first pivoted about the pin until upright. The post is tne secured in the upright position by allowing its bottom end to drop into the well, to the extent permitted by the lost motion of the pin within the slot.Such posts often in clude a key-operated locking mechanism to lock them in their erected position, and have proved useful in deterring improper use of parking bays and the like, but the typically short length of engagement between the foot of the erected post and the well, and dual use of the pin as both a pivot and one of the means to secure the erected post, have made such constructions less robust than is desirable where a barrier is needed-to prevent access to dangerous equipment.

The present invention arose from the need for a collapsible barrier comparably simple in construction and operation, but more robust when erected. According to the invention a collapsible barrier assembly comprises a base member, adapted to be fixed to the ground, and when so fixed to present an upward projection; a post unit having first and second limbs connected at a hinge, the construction of the limbs being such that they are each capable of sliding telescopically relative to the projection; and a connection, separate from the hinge and allowing lost motion, between the base member and the first limb; whereby at one extreme of the lost motion the hinge and part of the second limb are in engagement with the base member so that pivotting at the hinge is prevented and the two limbs are held in alignment with each other, while at the other extreme the hinge and second limb are out of engagement with the base member so the two limbs can pivot.

The lost-motion connection may be of pinand-slot type, in which case the pin may be supported by the base member and the slot may be presented by the first limb.

The projection may be sheath-like and the limbs of the post unit may slide telescopically within it..

The assembly may be arranged so that when the base member is fixed to the ground and the two limbs of the post unit are pivoted relative to each other, there is a natural rest position in which the hinge lies just above the upper end of the projection and the second limb is supported from the ground so that it rests horizontal. The base unit may be adapted to be recessed in the ground with the upper end of the projection lying substantially at ground level, so that the second limb in its rest position then lies on the ground.

The hinge, when out of engagement with the base member, may permit the second limb to swing to both sides of the vertical relative to the first limb.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic section through part of a post-type barrier assembly; Figure 2 is a perspective view of railings when erected, and Figure 3 is a perspective view of the same railings when collapsed.

The assembly shown in Fig. 1 includes firstly a post unit 1 comprising first and second tubular limbs 2 and 3 joined at a hinge 4.

First limb 2 is formed with a long slot 5, and second limb 3 fits within and is welded to a surrounding tube 6 which constitutes the main structural member of the barrier in use.

A base member 10 comprises a bottom plate 11 and an upward tubular projection 12, spanned by a pin 13 which passes through slot 5. Pin 13 and slot 5 constitute a lostmotion connection between base member 10 and post unit 1, and they are shown in Fig. 1 at one extreme position of their relative motion in which the pin 13 is at the bottom end of the slot. In this position hinge 4 and all of limb 3 lie clear of the top rim 14 of tube 12.

While limb 2 is held vertical by its engagement with tube 12, limb 3 and the structure 6 of the barrier are therefore free to pivot to right or left about hinge 4, so effectively "collapsing" the barrier to right or left. If however the limbs 2 and 3 are held in alignment as shown in Fig. 1, but the unit 1 is allowed to descend into base unit 10 until the pin 13 lies at the opposite (15) end of slot 5, the rim 14 of tube 12 will then be very close to the bottom edge 16 of structure 6. In this condition the hinge 4 and part of limb 3, as well as all of limb 2, will lie within tube 12. Mutual pivoting of limbs 2 and 3 about hinge 4 will therefore be prevented, and limb 3 and the attached barrier structure 6 will be constrained to stand vertical. The barrier is therefore erected.A horizontal force against structure 6 will not collapse it: collapse can only occur if the structure is first lifted vertically so that hinge 4 and limb 3 rise clear of the rim 14 of base member 10, and an accidental impact of some object with the barrier is unlikely to lift it vertically in that way.

Base member 10 is shown with its bottom plate 11 fixed to the surface of ground 17.

Alternatively member 10 could be recessed in the ground so that the rim 14-of tube 12 lay at ground level, in which case it will be apparent that the- natural rest position of the assembly when collapsed will be with structure 6 lying horizontal, in contact with the ground, and with hinge 4 lying just-clear of rim 14.

Figs. 2 and 3 show a practical embodiment of the invention in the form of railings. The barrier part of each section- of railings comprises two uprights 20, joined by two horizontal members 21. Each upright 20 co-operates with a base member 10 as-already described, and as will be seen from both figures the base plate 11 of each such member is in this embodiment fixed to the surface 17 of a platform on which the whole assembly is mounted. Reference 22 indicates that part of the platform lying to one side of the railings, where access is safe. The sloping structure 23, indicated best in Fig. 2, represents part of a hazardous construction which lies to the other side of the railings, and to which the railings prevent access when they are in their erected state as shown in that Figure.

In Fig. 3 two of the sections of railings are shown in their collapsed state. To collapse each- section from its erected state, an operator first lifts one of the horizontals 21 until the lower ends of limbs 3, and the hinges 4, come clear of the top rims 14 of base mem bers-lO. Limbs 3, and the railing structure (20m 21) attached to them, can then pivot to the collapsed position shown in Fig. 3. Because of the downward-sloping shape of the structure 23, in this case the natural rest position of the collapsed railing structure is not horizontal, but parallel with the sloping face of structure 23 and therefore downwardly-sloping as Fig. 3 clearly shows.

Separation of the pin-and-slot (13, 5) connection from the hinge (4) makes possible a far more robust engagement between limbs 2 and 3 and the base unit 10; when the barrier is erected, than would be possible if the pin 13 had also- to act as a hinge, as is the case with some of the known barrier constructions referred to earlier in this specification.

Claims

CLAIMS 1. A collapsible barrier assembly comprising: a base member, adapted to be fixed to the ground, and when so fixed to present an upward projection; a barrier unit having first and second limbs connected at a hinge, the construction of the limbs, being such that they are each capable of sliding telescopically relative to the base member; a connection, separate from the hinge and of lost-motion type, between the base member and the first limb, whereby at one extreme of the lost motion the hinge and part of the second limb are in engagement with the base member so that pivoting at the hinge is prevented and the two limbs are held in alignment with each other, while at the other extreme the hinge and second limb are out of engagement with the base member so that the two limbs can pivot at the hinge. 2. A collapsible barrier assembly acording to Claim 1 in which the connection is of pinand-slot type. 3. A collapsible assembly according to Claim 2 in which the pin is supported by the base member and the slot is presented by the first limb. 4. A collapsible barrier assembly according to Claim 1 in which the projection is sheathlike and the limbs of the post unit slide telescopically within it. 5. A collapsible barrier assembly according to Claim 1, arranged so that when the base member is fixed to the ground and the two limbs of the barrier unit are pivoted relative to each other, there is a natural rest position in which the hinge lies just above the upper end of the projection and the second limb is supported from the ground so-that it rests horizontal. 6. A collapsible barrier assembly according to Claim 4 in which the base unit is adapted to be secured in the ground with the upper end of the projection lying substantially at ground level, so that the second limb in its rest position lies on the ground. 7. A collapsible post unit according to Claim 1 in which the hinge when out of engagement with the base member permits the second limb to swing to both sides of the vertical relative to the first limb. CLAIMS Amendments to the claims have been filed, and have the following effect: Claims 1-7 above have been deleted or textually amended. New or textually amended claims have been filed as follows:-

1. A collapsible barrier assembly compris ing: a base member, adapted to be fixed to the ground, and when so fixed to present an upward projection; a barrier unit having first and second limbs connected at a hinge, the construction of the limbs being such that they are each capable of sliding telescopically relative to the base member; a connection, separate from the hinge and of lost-motion type, between the base member and the first limb, whereby at one extreme of the lost motion the hinge and part of the second limb are in engagement with the base member so that pivoting at the hinge is prevented and the two limbs are held in alignment with each other, while at the other extreme the hinge and second limb are out of engagement with the base member so that the two limbs can pivot at the hinge.

2. A collapsible barrier assembly according to Claim 1 in which the connection is of pinand-slot type.

3. A collapsible barrier assembly according to Claim 2 in which the pin is supported by the base member and the slot is presented by the first limb.

4. A collapsible barrier assembly according to Claim 1 in which the projection is sheathlike and the limbs of the barrier unit slide telescopically within it.

5. A collapsible barrier assembly according tio Claim 1, arranged so that when the base member is fixed to the ground and the two limbs of the barrier unit are pivoted relative to each other, there is a natural rest position in which the hinge lies just above the upper end of the projection and the second limb is supported from the ground so that it rests horizontal.

6. A collapsible barrier assembly according to Claim 4 in which the base unit is adapted to be secured in the ground with the upper end of the projection lying sub'stantially at ground level, so that the second limb in its rest position lies on the ground.

7. A collapsible barrier assembly according to Claim 1 in which the hinge when out of engagement with the base member permits the second limb to swing to both sides of the vertical relative to the first limb.

8. A collapsible barrier assembly according to Claim 1, substantially as -de-scribed with reference to the accompanying drawings.