GB2096810A - Secure site checking system - Google Patents

Abstract

Beneath the or each access 2, 3, 4 to a secure site 1 is located an induction loop 6 securely connected to a counter/display 9 and adjusted to count only those vehicles over a predetermined size e.g. waste disposal trucks but not automobiles, motorcycles, etc. <IMAGE>

Description

SPECIFICATION Secure site checking system This invention relates to an electrically operated counting method particularly adapted to record vehicular movement into, and optionally out of, a location having fixed access routes.

It is known to provide car-parking facilities with buried induction loops at access points whereby passage of vehicles in and out of the car park can be counted. Typically, such devices record both incoming and outgoing vehicles and any difference in the numbers is used to operate indicator signs showing whether the car park is full or still has parking spaces. Such loops, however, can be triggered by vehicles of differing sizes and because of this are not used for accurate counting of parking spaces but merely as a general guide with a margin of error, to the state of the car park.

It is also known to operate a traffic-light system by the use of buried induction loops in the road ahead of the traffic lights. Once again, these do not discriminate between types of vehicles since to do so would run the risk that certain categories of vehicle would not operate the lights and thus lead to accidents. Moreover, no counting function is carried out by such an induction-loop arrangement.

The present invention is concerned with the operation of a secure site, e.g. a waste-disposal or building site where individual counting of vehicles, and optionally selective counting of specified vehicle types, is necessary.

By way of example, the tipping of waste, especially tipping of unpleasant chemical or industrial waste material, is carefully controlled and regulated. In view of this most disposal sites are commercial undertakings which levy a charge on each vehicle-load of such waste. However, by their nature, such disposal sites are well away from habitation and commonly the control and checking of vehicles entering the site is in the hands of isolated and not closely supervised personnel. There is thus a possibility that vehicles can enter unobserved, or by collusion with the checking staff, so as to dump their load of waste without paying the full charge to the owners of the site. Since this charge is many times greater than the individual charges involved in a car park, there is a need for accurate automatic counting procedures.

An optional, but not always necessary feature is the provision of a means to discriminate between types of vehicles e.g. between a vehicle attracting a full charge and other classes of vehicle, such as for example a light car or a motor-bike or wheelbarrow used in connection with the site personnel but not producing income for the owners.

A further example of a secure site is a building site needing monitored delivery of ready-mixed concrete or of other material e.g. sand, gravel, cement, carried in heavy vehicles.

The present invention, in one aspect provides a method of operating a secure site which has one or more restricted routes of vehicular access, comprising embedding beneath the, or each, access route an induction loop or like member with a tamper-proof environment; running leads from this loop to a counter and/or recorder device, the leads and device also being located in a tamper-proof environment; and adjusting the sensitivity of the inductive loop so as to count only those vehicles passing over the embedded loop which are above a predetermined size.

Typically, the inductive loop can be arranged as a double loop of wire in a rectangular pattern, embedded within a concrete or like section over which the vehicle passes. The concrete can be laid at the time of installation or an existing roadway can be grooved into the desired configuration and the wires placed in the grooves and thereafter embedded with concrete or similar material.

Connecting wires from these loops can pass similarly through a concrete embedment into a tamper-proof device. One example of such a device to which the invention is not however limited is a metal pipe with one end embedded in the concrete containing the connecting wires and the counting and checking device suitably and securely housed therein.

Typical sizes for such a loop can be from two to ten feet wide and one to ten feet in the direction of travel.

A site of this nature is mostly used by relatively heavy trucks containing a considerable mass of metal. Occasionally, the operating personnel, or the owners, or a casual user, will enter by light automobile or possibly other vehicular transport.

Moreover, people may walk over the loop carrying or handling metal articles. With a inductive counter as used in a car park, the inductive loop picks up not only all cars entering and leaving (irrespective of size) but also occasional extraneous signals such as for example from bicycles or other metal articles. There is therefore always a margin of error built into the circuitry so that the signs indicating that the car park is full typically go up when one or two spaces remain.

This not of major commercial significance in the operating of the car park. However, in the operating of a secure site, where each charge for each load of material is significant, it is usually necessary to discriminate between a heavy vehicle carrying a load of material and extraneous signals caused by other metal articles crossing the loop, and because of this, a suitable control device such as a potentiometer may be adjusted (typically in site conditions so that local details of installation of the loop can be accommodated) and thereafter housed in a secure environment so as to prevent tampering by users or site personnel. If suitably adjusted the device can provide for automatic control of a site having restricted access points, thus saving the cost of personnel as well as eliminating losses due to unobserved or collusive use of the site.

The drawing shows a secure area generally indicated at 1 having an access opening 2 and if desired other access openings as indicated diagrammatically at 3 and 4. In each access opening there is a concrete base 5 which according to the invention can either be the existing concrete base or provided separate. In each concrete base there is a double rectangular loop of wire 6 embedded beneath the surface of the concrete, either when the concrete is initially laid or by cutting a shaped channel, placing the wires in the channel and covering then with fresh concrete. The loop is connected, again by subsurface wiring 7 to a pipe 8 bearing in its upper part a read-out box 9 which can if desired be sealed and locked. Within the circuitry of the readout box there is an adjustable potentiometer arrangement to control the sensitivity of the induction loop 6.

It will be understood that the other access openings 3 and 4 possess similar arrangements. If desired, these various access openings 3 and 4 can possess induction loops connected by common electrical connections to a single readout but this is not necessary and it may be more convenient to record the use of each access gate separately.

Suitable adjustment of sensitivity ensures that a heavy vehicle such as a truck will cause the counter to operate, whereas a light vehicle or manual device such as a wheelbarrow or bicycle does not cause the counter to operate and thus register the significant charge due to the owner of the site.

Operating personnel may be necessary to ensure that unauthorised vehicles do not use the site, but there is no risk of collusive use between the driver and the checking staff. Alternatively, different gates could be used by different users, the opening being locked shut except when used by a driver with the relevant key, and the necessary counting then being related to the use of that entrance only by authorised drivers. In such a case it is not necessary to use personnel on the gate.

Claims (1)

1. A method of operating a secure site which has one or more restricted routes of vehicular assess, comprising: embedding beneath the, or each, access route an induction loop or like member within a tamper-proof environment; running leads from this loop to a counter and/or recorder device, the leads and device also being located in a tamper-proof environment; and adjusting the sensitivity of the inductive loop so as to count only those vehicles passing over the embedded loop which are above a predetermined size.

2. A method as claimed in Claim 1 in which the loop is embedded as a double loop in a rectangular shape within a concrete or like section over which the vehicle passes.

3. An installation at a vehicular access to a secure site, comprising a section of road surface; a loop of wire or like material embedded beneath the surface; electrical connections between said loop and a secure tamper-proof enclosure; adjustment means within said enclosure whereby the inductive effect in said loop caused by the proximity of a vehicle can be screened below a predetermined level; and a counting device within said secure enclosure for indicating or recording the instances of an inductive effect above the predetermined level.

8. An installation as claimed in Claim 3 in which the loop is a double loop of wire arranged in a rectangular pattern and embedded within a concrete or like section.