GB2195384A

GB2195384A - Retractable post assembly

Info

Publication number: GB2195384A
Application number: GB08722352A
Authority: GB
Inventors: David John Akhurst
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-09-26
Filing date: 1987-09-23
Publication date: 1988-04-07
Anticipated expiration: 2007-09-23
Also published as: GB2195384B; GB8722352D0

Abstract

A retractable post assembly comprises a ground-mounted, pivoted tube (3) supported by a diagonal brace (11), said brace having a movable pivot axis (15) and is prevented from collapsing by a structural catch (18,19) formed between the two parts (10,12) of the brace and which resists any impact on the brace tending to compress it. A lock (20) is provided in order to maintain the parts of the brace in the condition in which the catch is effective. The assembly is suitably used to restrict entry to a parking place. <IMAGE>

Description

SPECIFICATION Post This invention relates to a post intended to restrict entry to a place such as a parking place.

The posts most widely used at present consist of a single metallic tube pivoted at its base in a slot in a ground-mounted plate which contains a hole for accommodating the diameter of the tube. When access is open to that area the tube iies on the ground. When the area is to be closed off the tube is pivoted to a vertical position and lowered so that its foot rests in the hole in the groundmounted plate. It is then locked there.

The disadvantage of the above described post is that when a moving object strikes the tube when vertical, the tube or its pivot pin will bend and the post becomes ineffective.

The present invention sets out to redirect the moments of force imposed on the post and tube, therefore significantly decreasing the damaging effects of an impact on the tube.

According to the present invention there is provided a structure consisting of a base plate, a tube pivoted about a horizontal axis to be movable from a vertical to horizontal condition and a diagonal brace element which intersects, extending from the tube when vertical to the base plate to maintain the tube in its vertical condition. The diagonal brace can be seen to form with the tube when erected and the base a structure having a significantly greater strength than the post supported only at the pivot and the base plate as in the prior art.

The lock for locking the post to prevent unauthorised access to the place guarded by it is provided on the diagonal brace. The brace will be extensible, for example by being telescopic or by being foldable, so as to allow pivotal movement of the tube relative to the base while the brace remains permanently attached to the tube and to the base. The lock may therefore conveniently be provided to prevent relative movement of the parts of the brace.

In a particularly preferred construction, means are provided whereby the lock does not have to sustain the force, or at least any substantial part of the force, of an impact on the tube when erect. This may be arranged for example by arranging on mutually movable portions of the brace a structural catch interacting between those parts and sustaining all or at least a major part of any force tending to collapse the brace from that condition, while the lock merely maintains the portions of the brace in the condition in which the catch is effective.More specifically this function may be achieved by having the two parts of a folding brace able to move axially relative to each other, in a first axial position a ledge on one of the two parts catching on a nose on the other to prevent relative pivotal displacement of the two parts while in a second axial position the nose is brought free of the ledge so as to permit the pivotal movement, the lock acting to hold the two parts in the first position.

To provide stiffness of the assembly when the tube is in the collapsed,substantially horizontal condition it may be arranged that lugs attaching the brace to the tube fit within a channel section of a portion of a foldable brace adjacent the pivot point of that channel section on the base plate; in this way any lateral impact on the post when collapsed is resisted through the pivot of the diagonal brace as well as through the pivot of the tube.

A specific embodiment of the invention will now be described with reference to the accompanying drawing wherein: Figure 1 is a perspective view of the embodiment; Figures 2 and 3 are side views of a portion of the embodiment, in respectively different conditions; and Figure 4 is a perspective partial view of the post in an almost-collapsed condition.

The post seen in Figure 1 has a T-shaped base plate 1 of which the head 2 is of dimensions to match the base plate of the existing prior art posts, so that the base plate can be fitted where existing posts have been removed, even using the same holes in the ground for receiving rag bolts.

A square section hollow tubular post 3 with a top cap 4 is pivoted by pin 5 in. lugs 6 on the base plate. Pin 5 is borne within a sieeve 7 welded to one side of the square tube 3, at its base end.

More than halfway up the tube 3, lugs 8 receive a pivot pin 9 of a first part 10 of a diagonal brace generally indicated as 11 and which has a second part 12. The second part 12 is journalled on the base 1 by means of a pin 13 working in lugs 14 on the base.

The two parts 10 and 12- of the brace 11 are pivoted together by a pin 15 working in a sleeve 16 welded to one end of the part 10, and the ends of which run in slots 17 in the walls of the channel 12. On the base of the part 10 there is welded at an appropriate position a plate 18 which forms a catch with a nose part 19 of the base of the channel 12, the extreme end of which nose part may be chamfered backward. In the position shown in Figure 2, where the pin 15 is at one end of the slot 17, the catch formed by the plate 18 is engaged with the nose and the two parts of the brace cannot pivot.

In the position shown in Figure 3 however where they have been mutually axially separated as far as possible and the pin 15 is at the top end of the slot 17, the plate 18 has come free of the nose 19 and the two parts may pivot.

A lock 20 has a shaft which when projecting engages in a hole 21 in the part 10. This hole 21 is in register with the shaft only when the pivot pin 15 is at the bottom end of the slot 17 and the catch is engaged i.e. in the position shown in Figure 2. Thus it can be seen that the function of the lock is not to withstand the forces exerted on the brace if the post is pushed while the brace is erected.

It receives none or substantially none of such force. Its function is to prevent the catch becoming disengaged, as has been done when the lock 20 has been released as in Figure 3.

When that pivoting occurs, the post is free to lower to a horizontal condition in which its previously uppermost end may be received on a rubber buffer block 22. As it approaches that condition, the lugs 9 being inset from the edges of the tribe 3 fit closely mutually inside the side walls of the channel part 12, and their entry into that channel may be assisted by chamfering of the edges of the lugs 9 as seen at 23. In this way when the post is fully lowered, any attempt to move it laterally is resisted by transmission from the lugs to- the side walls of the channel 12 near to the base lugs 14 thus preventing once more excessive moment on the main pivot 5. The offsetting of that pivot 5 from the centre line of the tube 3 gives some slight elevation to the tube when in the horizontal position to allow the folded diagonal brace to lie beneath it.

To erect the post, the tube is lifted to straighten the brace 11. While the brace is held straight the tube is then pushed back slightly to move the parts 10,12 of the tube axially together and engage the catch. This action may be aided by a spring within the brace. The lock is then applied to enter the shaft into the hole 21, automatically or by a deliberate manual action.

Claims

1. A post having a tube adapted to be pivotally supported about a first horizontal pivot axis on the ground, to be movable between erect and collapsed conditions and a brace attached at a fixed point on the tube about a second horizontal pivot axis and adapted to be- attached at a fixed point on the ground about a third horizontal pivot axis spaced from the first, the brace being collapsible to allow the said movement of the tube, and a lock on the brace to prevent that collapse.

2. A post according to claim 1 wherein the brace has two parts hinged near the centre of the brace about a fourth horizontal pivot axis and having a play about that axis whereby the two parts are axially movable relative to each other, in a first relative axial position a detent on one of the parts catching on the other part to prevent relative pivotal displacement of of the two parts of the brace and in a second relative- axial position the detent being free of the other part to permit relative pivotal displacement of the two parts of the brace about the fourth pivot axis.

3. A post according to claim 2 wherein in the first axial position the engagement of the detent and the other part is such as to withstand compressive force along the brace substantially without movement from the first axial position.

4. A post according to claim 2 or claim 3 in which the lock is provided to interact between the two parts of the brace when in the first axial position to maintain them in that first axial position.

5. A post according to any one of claims'2 to 4 in which lugs attaching the brace to the tube fit within a channel section of a portion of the brace adjacent to the third pivot axis.

6. A post according to any one of the preceding claims including abase part fixedly bearing the first and third pivot axes.

7. A post substantially as herein described with reference to and as illustrated in the accompanying drawings.