GB2239337A - Boat counter - Google Patents

Abstract

Apparatus for counting boats passing along a canal comprises means 12, 14 for generating first and second beams of electromagnetic energy. Detectors 22, 34 detect when both beams are broken within a predetermined time period, and at least one counter is actuated in response to such a detection. Infra-red beams may be used. Three counters may be provided, one counting boats moving upstream, one counting boats moving downstream, and one counting the total. <IMAGE>

Description

MOVING ARTICLE COUNTER This invention relates to apparatus for counting moving articles and is particularly although not exclusively applicable to counting boats passing along a canal. To the best of Applicant's knowledge and belief, hitherto no means of counting boats moving along a canal without human intervention has been available. Hence water authorities have been without reliable 24-hour data on canal usage and have had to make decisions on water supply and other matters without fully adequate information. It is among the aims of the present invention to reduce or remove this problem.

According to the present invention in its broadest aspect, an apparatus for counting moving articles moving past the apparatus comprises means for generating a first and a second beam of electromagnetic energy each of which intersects the path, means for detecting when both beams are broken within a predetermined time period, and means for actuating at least one counter in response to such a detection.

According to one aspect the invention, there is provided apparatus for counting articles moving past the apparatus comprising first and second generators each capable of producing an infra-red beam and spaced from one another substantially in the direction of travel of the articles, first and second receivers each located on the opposite side of the travel path to a corresponding generator, means for transmitting a signal (from the first receiver) to a first switch in a counter unit when the first beam is broken and for transmitting a second signal for a second switch in the counter unit when the second beam is broken, the arrangement being such that a count is registered by the counter unit only when both switches have received beambroken signals within a predetermined time period.

In a preferred embodiment of the invention, the counter unit includes three counters, one registering boats moving upstream, one registering boats moving downstream, and the third registering the total.

In another aspect of the invention, the receiver may be located in combination with or adjacent to the transmitter, and first and second beam reflectors may be located on the opposite side of the canal or river bank to the transmitters.

The invention will be better understood from the following non-limiting description of an example thereof given with reference to the accompanying drawings in which: Figure 1 is a schematic plan of a canal lock at which is installed an example of apparatus according to the invention; Figure 2 is a front elevation and Figure 3 is a section on III-III in Figure 2 showing the installation of one of the receivers in a canal wall.

Figure 4 is a schematic circuit diagram illustrating the operation of apparatus according to the invention.

Referring firstly to Figure 1, the illustrated apparatus according to the invention includes infra-red beam generators 12 and 14 which are set into the wall of a canal 16 at the entrance to a canal lock 18. At its upstream end the lock 18 has a single gate 20, there being a pair of gates 22 at its downstream end.

Set into the opposite wall of the canal 16 are a complementary pair of receivers 32 and 34 which are connected to a counter unit 36. The counter unit 36 is supplied by electric power from a power source 38, via a line 40. The continuation of the canal 16 is shown at 26. Also shown in Figure 1, although not forming part of the novelty of the present invention, are a lock state recorder 50, and a lock counter drop tube 52. These items will be familiar to one skilled in the art, but need not be further described in the present specification.

Figures 2 and 3 illustrate the installation in the canal wall 56 of infra-red beam generator 12. The towpath is shown at 56 A part 58 of the front wall of the beam generator is transparent to infra-red rays.

Although the invention may embody a beam generator co-operating with a receiver at the other side of the canal, in certain circumstances it may be preferable to employ a unit which contains a transmitter and receiver in one housing co-operating with, on the opposite side of the canal, a reflector mounted to reflect a beam emanating from the transmitter directly to its associated receiver. In either event, the manner of operation of the invention is essentially the same in that a boat passing breaks the beam and initiates a counting operation as will be later described.

Referring now to Figure 4, this is a diagrammatic representation of the circuitry by which the passage of a boat past the relevant area causes the total count and the upstream count or the downstream count to be advanced by one unit. Because of the positioning of the beam generators 12, 14 and the receivers 32, 34 at a narrow portion of the canal, only one boat can pass at a time. The circuitry includes an upstream infra-red beam generator 12 and a downstream infra-red beam generator 14 both connected to four relays or switches, namely relay one upstream 320, relay two upstream 322, relay one downstream 340, and relay two downstream 342. Each of these relays is associated with a respective time delay circuit 324, 326, 344 and 346. The counter unit 380, shown as encased by a chain dotted line, comprises a total counter 370, an up counter 330, and a down counter 350.A counter driving circuit 328 is connected to the up counter 330 and the total counter 370, and a similar counter driving circuit 348 is connected to the down counter 350 and the total counter 370.

With this arrangement, when a boat moving downstream passes between the upstream generator 12 and the upstream receiver 32, the beam is interrupted and after a time delay determined by the time delay circuit 324 a signal is issued which changes the state of the relay 320. This change of state of the relay 320 permits power to be supplied to the counter driving circuit 328.

This change of state of relay 320 is also arranged to ensure that relay 322 is placed in a condition so that no power can be applied to 328. Continued movement of a boat in a downstream direction breaks the beam between downstream generator 14 and receiver 34 with the result that a signal is fed after a time delay 326 to the second upstream relay 322 changing its state and causing power to be fed to the counter drive circuit 328. This counter drive circuit 328 responds only when it receives power inputs from both relay 320 and 322 and, upon receiving said two inputs, drives each of the counters 330 and 370 on by one unit.

When the beam received by the upstream receiver 32 is broken a signal is also fed to the second downstream relay 342 but since at that time the first downstream relay 340 has not been energised the relay 342 is unable to pass on the signal from the upstream receiver 32.

On the other hand, in the case of a boat travelling in an upstream direction along the canal, the boat first intercepts the beam between the downstream generator 14 and receiver 34 and the breaking of this beam causes a signal to be applied to downstream relay 340 and this effects a change of state of downstream relay 342. Downstream relay 342 is accordingly in this situation in condition to receive and pass on the signal from upstream receiver 32 when it arrives shortly thereafter due to the upstream beam being broken by the upstream-travelling boat. Hence in this situation outputs from relays 340 and 342, appropriately time delayed by time delay circuits 344 and 346 both reach the drive circuit 348 for the down counter 350 and the total counter 370 and cause one unit advance in the down counter 350 and the total counter 370.

While in the above discussion reference has been made to relays, it will be appreciated that any electrical switch or solid state switching device such as a transistor or indeed any integrated circuit incorporating the functions of the relays, the time delay circuits and the drive circuits could be employed instead.

A man skilled in the electrical arts will be able to devise and build appropriate circuits from commercially available components, once having read the present disclosure. Accordingly, the present invention is not considered to be limited to the use of the components and apparatus particularly described in this specific description and illustrated in the accompanying drawings.

Other modifications may also be made without departing from the invention. For example, while infra-red beams have been specifically described, one could employ as an alternative beams of light at the red end of the visible spectrum. However, to reduce the chance of vandalism and to avoid generating uncertainties in the minds of those using the canal, non-visible electromagnetic radiation is preferred.

Of course normal precautions would be taken against ingress of water and interference or vandalism by building the housings of the components of the apparatus according to the present invention of appropriately strong and durable materials.

Claims (6)

1. An apparatus for counting moving articles moving along a path past the apparatus comprising means for generating a first and a second beam of electromagnetic energy each of which intersects the path, means for detecting when both beams are broken within a predetermined time period, and means for actuating at least one counter in response to such a detection.

2. Apparatus for counting articles moving along a path past the apparatus comprising first and second generators each capable of producing an infra-red beam and spaced from one another substantially in the direction of travel of the articles, first and second receivers each located on the opposite side of the travel path to a corresponding generator, means for transmitting a signal from the first receiver to a first switch in a counter unit when the first beam is broken and for transmitting a second signal from the second receiver to a second switch in the counter unit when the second beam is broken, the arrangement being such that a count is registered by the counter unit only when both switches have received beam-broken signals within a predetermined time period.

3. Apparatus according to claim 1 or 2 in which the counter unit includes three counters, one registering boats moving upstream, one registering boats moving downstream, and the third registering the total thereof.

4. Apparatus according to claim 2 or claim 3 when dependent on claim 2 in which the receiver is located in combination with or adjacent to the transmitter, and first and second beam reflectors are located on the opposite side of the canal or river bank to the transmitters.

5. A boat counter substantially as described and illustrated herein with reference to and as illustrated in the accompanying drawings.

6. Any novel combination or sub-combination disclosed and/or illustrated herein.