GB2406388A - Apparatus to assist in the manual application of force to test stability of graveyard monuments and other upstanding structures - Google Patents

Abstract

The applicator consists of an L-shaped support stand. The weight of the operator is applied near the corner of the L, so that the test force against the monument can be applied from the stand without causing the applicator to tip or lift. The applicator is designed for applying the test force via an instrument that will signal for the build up of force to be terminated when a specified test force is reached. Under the conditions in which the device is to be used considerable deflection of the equipment has to be expected (lost motion) before the test force can be built up. A mechanism 1 as commonly known for actuating Sealant Guns or Caulking Guns, or a screw system with release mechanism similar to that employed on bench-mounted vices, is therefore used to apply the force, accommodating the lost motion.

Description

Apparatus to assist in the manual application of Force to test stability

of monuments The apparatus (the Force Applicator) is intended particularly (but not exclusively) for use In testing the stability of monuments in graveyards It may also be useful for testing the stability of other upstanding structures generally (such as posts, pillars, street furniture, playground equipment, etc.) Monuments in graveyards (gravestones) have been the cause of numerous serious accidents, resulting from their ability to fall over This can occur when people pull themselves up on the stone from a sitting or kneeling position, when leaning against the monument, when children play In the graveyard, etc It is therefore good practice, and has now become the subject of national directives In preparation, to test the stability of such structures The test requires the application of a specified force at a specified height The use of excessively high forces must be avoided, as a large number of monuments would be failed unnecessarily The force Is selected on the basis of a compromise between the force that might be applied In practice under extreme conditions and the force normally likely to be Involved - a reasonable maximum Is selected.

The force Is applied via an Instrument (see Fig 1) When the specified test force has been built up a buzzer or similar device Is energised, signalling to the operator to stop. The Instrument may also have a readout facility showing the force being applied during the test, and the maximum reached. The Instrument consists of pressure pad (2) made of rubber or a material of similar properties attached to a plunger (3) going Into the Instrument housing (4) that actuates the signalling system The plunger Is moved through a short distance during the build up of force Handles (5) are attached to the housing to enable the operator to apply the force. Facilities are provided to attach a second pair of handles (6) so that, If required, two operators can be used to apply the required force This faculty can also be used for fitting the handles for one operator In different positions so that the operator can change his grip - 1

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To apply this force directly for test purposes repeatedly in a sequence of testing perhaps hundreds of monuments makes severe demands on the test Instrument operator or operators The purpose of the Force Applicator is to make this testing procedure easier.

The Applicator must provide mechanical advantage for the application of the test force. The mechanical advantage could be derived from a single lever or a lever mechanism such as that illustrated in our earlier application GO 0301053 5, a cam system, a hydraulic or pneumatic system, or a wedge system.

However, in order to meet, in a practical manner, also the need to take up the 'lost motion' described further below, the use of a more special mechanical system as further described in this application, or a screw system, is required It is essential for the purpose for which the device is intended, to accommodate, as far as is reasonably practical, the conditions resulting from the greatly varying conditions of the test sites. The force applicator may be set up on surfaces that may be soft or hard (including polished stone), flat or uneven, and there may be obstructions or the monument may not stand vertical. As a result, there is generally a requirement for considerable movement of the pressure pad ap,olying the force ('lost motion') before the pressure can be built up.

In order to push the Instrument shown in fig 1 so as to take up the 'lost motion' and then to apply the force, it is proposed to use a mechanism of the type known variously as the mechanism employed on Sealant Applicator Guns or Caulking Guns as indicated in fig 2 item1, or a screw system with release similar to the type commonly fitted to a bench mounted metalworking or woodworking vice for fast closing up.

These types of mechanism enable forces as required (and higher forces) to be built up with very little demand on physical strength The Instrument and the push mechanism 1 in fig 2 are held in the Carrier 7. The Instrument can be made to slide forward (towards the monument), sliding in the slot 8, by means of the push mechanism. The pivot mounting 9 and a force transmission arrangement 10 enables the force to be applied perpendicularly via the Instrument to the monument even if the monument Is not standing vertically. - 2

The Applicator may allow the Instrument still to be used Independently for cases where the adverse site conditions as described earlier, or space restrictions, are particularly severe The Instrument can then simply be detached or lifted out of the carrier using the slot 11 provided for this purpose The Carrier 7 Is attached to the upright or pillar 12 of the Applicator as shown In fig 3 in such a way that it can be positioned vertically in accordance with the height at which the force is to be applied (normally close to the top of the monument) A sleeve 13 attached to the Carrier 7 can slide up and down on the pillar or upright 12 onto which it can then be clamped with the clamping arrangement 14. Alternatively a rack and pinion or locating device to lock it in position can be used There may be provision to locate the Carrier 7 in different positions horizontally to allow for extra reach, e.g In the event of an obstruction at the base of the monument, by providing additional sleeves 13 in different positions The base plate or platform 15 in fig 3 on which the upright is mounted is provided with ifeet' 16 incorporating rubber or similar material to prevent damage if the Applicator is placed on a stone slab and to prevent slipping when the force is applied The base plate is also of sufficient size so that, making use of the weight of the operator, it Will not tip (lift at the front edge) when the force is applied.

The pillar or upright 12 required for taller monuments may be made In two parts so that the upper section can be taken off when there are no taller monuments to be tested, thus making it easier to handle the equipment.

The Applicator may be provided with a carrying handle 17 and, for transporting greater distances and storage, there may be provision for the upright 12 to be folded down against the base 15 The Force Applicator may also be fitted with a wheel or wheels

Claims (2)

1 The use of a mechanism of the type known variously as the mechanism employed on Sealant Applicator Guns or Caulking Guns to take up the 'lost motion' and then build up the test force required for the controlled testing of the stability of grave stones, monuments or other structures that may present a similar lack of stability hazard, without the need for high physical force from the operator.

2 T he use of a screw system with release similar to the type commonly fitted to a bench mounted metalworking or woodworking vice to take up the 'lost motion' and then build up the test force required for the controlled testing of the stability of grave stones, monuments or other structures that may present a similar lack of stability hazard, without the need for high physical force from the operator - 4