GB2091888A

GB2091888A - A testing unit for crash barriers

Info

Publication number: GB2091888A
Application number: GB8138114A
Authority: GB
Original assignee: GILMAT ENGINEERING Ltd
Current assignee: GILMAT ENGINEERING Ltd
Priority date: 1980-12-18
Filing date: 1981-12-17
Publication date: 1982-08-04
Also published as: GB2091888B

Abstract

A unit for testing the crash barriers on the terracing of, for example, a football ground comprises a telescopically adjustable boom 5 mounted for vertical adjustment on a three legged trolley (1). One of the legs (3) of the trolley (1) is adjustable so that the trolley can be wheeled along steps with that leg on a different step to the two legs. One end of the boom carries an angle piece 13 for engaging a step and the other end carries deflection monitor 24,25 and a piston and cylinder device 18, the piston 22 of which is connected to a vee-pod 23 for engaging a crash barrier. In use the boom is adjusted to the length required to bridge the gap between an upper step and lower crash barrier. Pressure fluid is supplied to the piston and cylinder device to deflect the barrier and the deflection is measured by the monitor. <IMAGE>

Description

SPECIFICATION A testing unit The present invention relates to a test unit and is particularly, but not exclusively, intended for use in the testing of barriers on the terraces of sports grounds.

Because of the great mass of people often lined up behind these barriers, they have, on occasion collapsed, with consequent injury and/or loss of life. In an attempt to reduce such accidents, barriers of this nature are subjected to a testing deflection force and the deflection measured in order to assess how the barriers would operate in practice. An object of the present invention is to design and produce a machine for this task.

According to the present invention, there is provided a test unit comprising a base, a central elongate boom which is adjustable in length mounted on the base so as to be adjustable in height relative to the base, means associated with the boom for subjecting the boom to a force so as to subject a unit under test to a displacement force and means for measuring the deflection of the unit under test when so subjected.

A preferred embodiment of the invention may comprise any one or more of the following advantageous features: (a) The means associated with the boom comprises a pressure fluid operable piston and cylinder device.

(b) The piston and cylinder device of (a) is hydraulic.

(c) The piston and cylinder device of (a) is pneumatic.

(d) The means associated with the boom is connected to one end of the boom and a stop is connected to the other end.

(e) The angle of the stop is adjustable relative to the boom.

(f) The stop of (e) is an angle pivotally connected to the boom.

(g) The boom is telescopic and means are provided for holding the different sections of the telescope in different relative positions appropriate to different effective lengths of the boom.

(h) The mounting of the boom on the base comprises a screw and associated hand wheel which can be turned to turn the screw to raise or lower the boom relative to the base.

(i) The means for measuring deflection comprises a linear scale fixed relative to the piston or cylinder of the piston and cylinder device and an indicator fixed relative to the cylinder or piston of the device.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the single Figure of the accompanying drawing, which shows a diagrammatic view of a test unit.

Referring to this Figure, the unit comprises a base in the form of a three wheeled trolley 1. The wheels 2 are disposed at the bottom of the legs 3 of the trolley and one of those legs is adjustable in height by means of handle 4. This adjustability enables the unitto be pushed along terraced steps with one wheel 2 on one step and another wheel 2 on another step whilst maintaining the unit in a normal stable attitude.

A boom 5 is supported on the trolley by means of a vertical support member 5 which houses a screw 6 at the upper end of which is disposed a gimbal bearing 7. The screw 6 can be turned by means of a hand wheel 8 to raise and lower the screw 6 and therefore the boom 5 supported on it.

The boom 5 comprises two tubes 9 and 10, tube 10 being slidably mounted inside tube 9. A slot 11 is formed in the larger diameter tube 9 in which a pin 12 is inserted to locate the boom 5 relative to the gimbal bearing 7 in such a way as to allow relative lateral movement. Slot 11 is formed substantially at the centre of gravity of the boom 5. Tube 10 carries a pivotable angle piece 13 at its free end. Tube 9 is externally screwthreaded at 14 and a complementary internallyscrewthreaded collar 15 is mounted on the tube 9. The collar can be rotated by means of a handle 16 to move it longitudinally of the tube 10 to provide an adjustable stop for the inner tube 10 in conjunction with a pin 17 extending through slot 18 provided in the tube 9 for that purpose.

At the end of the boom 5 remote from the angle piece 13 is disposed a hydraulic piston and cylinder device 18 fed from a hydraulic hand pump 19. A pressure gauge 20 is disposed in the feed line 21 from the pump to the device 18. Connected to the piston 22 of the device 18 is a vee-pod 23 shaped to fit around the upper part of a standard crush barrier.

A deflection monitor is provided. This comprises a tubular linear scale 24 clamped to the barrel of the cylinder of the device 18 through which a bar 25, which is attached to an annulus which runs free on the diameter of the vee-pod, slides, to register deflection and recovery of the crush barrier beam.

The linear scale 24 may be adjusted axially by slackening a knurled thumb-screw 26.

In use of the unit, the trolley is wheeled along the terraces to the appropriate position. The boom 5 is then extended so that the vee-pod 23 locates on the upper horizontal member of the crush barrier itself and the angle piece 13 locates on an upper step above the crush barrier, and is tightened in that position by rotating the collar 15 appropriately to further extend the tube 10 from the tube 9. Pressure fluid is then supplied from the hand pump 19 to the hydraulic piston and cylinder device after first zeroing the deflection monitor. The fluid supply in this example is such as to simulate crowd pressures of 400 Ibs per foot UDL (uniformly distributed load) on the barrier, although this force can be varied as required.The deflection under load and the barrier recovery after removal of the load is measured by the deflection monitor and these readings compared with standard deflections considered accepable.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the scope of the invention. For example, the piston and cylinder device may be pneumatic. Also, the boom 5 can with advantage be made in modular lengths of say one metre in order to facilitate disassembly for storage pruposes. Furthermore, parts such as the pump 19 can be mounted on the trolley 1 in orderto lower the centry of gravity of the unit to render it more stable. The pump may additionally be detachable to promote simplicity of storage and to improve security. It will also be appreciated that the above described unit is versatile in that its adjustable features enable it to be operated in varying terrace dimensional conditions.

Claims

1. A test unit comprising abase, a central elongate boom which is adjustable in length mounted on the base so as to be adjustable in height relative to the base, means associated with the boom for subjecting the boom to a force so as to subject a unit under test to a displacement force and means for measuring the deflection of the unit under test when so subjected.

2. Atest unit as claimed in claim 1, in which the means associates with the boom comprises a pressure fluid operable piston and cylinder device.

3. A test unit as claimed in Claim 2, in which the piston and cylinder device is hydraulic.

4. A test unit as claimed in Claim 2, in which the piston and cylinder device is pneumatic.

5. A test unit is claimed in any preceding claim, in which the means associated with the boom is connected to one end of the boom and a stop is connected to the other end.

A test unit as claimed in Claim 5, in which the angle of the stop is adjustable relative to the boom.

7. Atest unit as claimed in Claim 6, in which the stop is an angle pivotally connected to the boom.

8. Atest unit as claimed in any preceding claim, in which the boom is telescopic and means are provided for holding the different sections of the telescope in different relative positions appropriate to different effective lengths of the boom.

9. A test unit as claimed in any preceding claim, in which the mounting ofthe boom on the base comprises a screw and associated hand wheel which can be turned to turn the screw to raise or lower the boom relative to the base.

10. Atest unit as claimed in any preceding claim, in which the means for measuring deflection comprises a linear scale fixed relative to the piston or cylinder of the piston and cylinder device and an indicator fixed relative to the cylinder or piston of the device.

11. Atest unit as claimed in any preceding claim, in which the base comprises three legs one of which is adjustable in length relative to the others to facilitate mounting the base on steps or sloping ground.

12. Atest unit as claimed in any preceding claim, in which the boom is made up of modular component lengths.

13. A test unit as claimed in Claim 2, or in any of claims 3 to 12 when appendantto Claim 2, in which a pump is provided for the supply of pressure fluid to the piston and cylinder device.

14. Atest unit as claimed in Claim 13, in which the pump is detachably disposed in the base in order to lower the centre of gravity of the unit.

15. A test unit substantially as hereinbefore described with reference to the accompanying drawings.