GB2274589A

GB2274589A - Microwave radiating apparatus for pest control

Info

Publication number: GB2274589A
Application number: GB9301790A
Authority: GB
Inventors: Stephen Philip Rowe; David Leslie Edward Hobby
Original assignee: Roke Manor Research Ltd
Current assignee: Roke Manor Research Ltd
Priority date: 1993-01-29
Filing date: 1993-01-29
Publication date: 1994-08-03
Also published as: GB9301790D0

Abstract

Pest control apparatus comprising a microwave radiation source (3) contained in a first housing (2), which source is adapted and arranged to be controlled remotely by control apparatus contained in a second housing (6), and microwave shielding means (9) which serves to protect personnel from microwave radiation emanating from the said source. Advantageously the apparatus can be used for the control or extermination of wood boring pests, eg long thorn beetle larvae in antique furniture thus avoiding the use of chemical sprays and impregnation. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO PEST CONTROL APPARATUS This invention relates to pest control apparatus, and more especially it relates to apparatus for the control or extermination of wood boring pests.

It is well known to control wood boring pests by using chemical sprays and/or impregnation techniques, but for some applications such techniques cannot be used or are preferably avoided.

One particular problem, with which this invention is concerned, is infestations of the Long Horn beetle larvae in furniture. In dealing with this problem it is quite often undesirable, with valuable antique pieces, to use chemical sprays or impregnants. Furthermore, with this particular pest, although considerable damage may be done internally to wooden structural members, external evidence such as entrance holes or apertures through which chemicals can be introduced, may be minimal.

It is therefore an object of the present invention to provide pest control apparatus which can be used to provide a remedy for the foregoing problems.

According to the present invention, pest control apparatus comprises a microwave radiation source contained in a first housing, which source is adapted and arranged to be controlled remotely by control apparatus contained in a second housing, and microwave shielding means which serves to protect personnel from microwave radiation emanating from the said source.

The control apparatus may be linked for control purposes to the microwave radiation source by means of a cable which serves as a power/communication link, or by means of a communication link which uses radiation such as ultrasonic, infrared, or radio frequency radiation as an information carrier.

The communication link may comprise a transmitter which forms a part of the control apparatus and a receiver operatively associated with and contained in the same housing as the microwave source.

The communication link may comprise a transponder arrangement including a first transmitter/receiver which is contained in the first housing with the microwave source and which is arranged in communication with a second transmitter/ receiver which forms a part of the control apparatus, thereby to define a feed back control loop by means of which predetermined control of the said source is effected.

The feed back control loop may include or form a part of a distance sensor circuit responsive to the distance between the control apparatus and the said microwave source for operating an "interlock" by means of which the said source is switched off so that it cannot be energised to radiate microwave energy unless the control apparatus is spaced away from the said source by more than a predetermined distance.

Alternatively, and/or additionally, operation of the microwave source may be controlled in dependence upon a personnel sensor which serves to detect the presence of personnel within a predetermined distance of the source and which provides a signal in dependence upon which the said source is operationally inhibited.

The personnel sensor may be responsive to infrared radiation.

The microwave radiation source may be adapted and arranged to form a part of an energy control loop, including a sensor responsive to radiation from the said source, or responsive to an effect produced by this radiation for producing a feed back control signal which serves to limit the time for which the source is energised.

This sensor may be a microwave radiation sensor placed and located so as to sense the radiation produced at a predetermined location adjacent to an article when irradiated.

Alternatively, the sensor may be a temperature sensor for example which is used to sense the heating effect produced by the source in or on an article to be irradiated.

One embodiment of the invention will now be described with way of example only with reference to the accompanying drawing, in which: FIGURE 1 is a somewhat schematic block diagram of apparatus for irradiating furniture; and FIGURE 2 is a somewhat schematic block diagram of apparatus for irradiating furniture which is remotely controlled via a radiation communication link.

Referring now to Figure 1, apparatus for the irradiation of furniture with microwaves (which in this example is a chair 1), comprises a first housing 2 which includes a microwave source 3 which might be defined by a magnetron. The microwave source 3 is driven by power from a transformer 4. The transformer would normally provide the necessary EHT and heater voltage's for the magnetron in accordance with well established techniques. Power for the transformer 4 is fed thereto via a cable 5 from control apparatus contained within a housing 6. The control apparatus in the housing 6 comprises a switch 7 via which power is supplied to the transformer 4 from the a.c. mains via the cable 5, operation of the switch being effected by a microwave power controller 8. The controller 8 would normally comprise means (not shown) for controlling the total time during which is power provided.In addition, power control means (not shown) may be provided which serves to control the total energy radiated by the microwave source 3 by effecting variation of the ratio between the time for which the microwave source is on as compared the time for which it is off, i.e. control of the duty cycle. In order to protect personnel, the article of furniture to be irradiated is arranged to be screened by means of microwave absorbent material 9.

With the arrangement thus far described with reference to Figure 1, it might be arranged that the control apparatus is spaced away from the microwave source by several metres and accordingly an appropriate length of cable 5 would be provided.

Although not shown in Figure 1, automatic control of the power delivered by the said source 3 may be provided for, and this may be achieved by means of a sensor as hereinafter be described with reference to Figure 2.

Referring now to Figure 2, an article of furniture 10 (i.e. an antique chair) to be irradiated is placed in front of a shield or screen 11, made of microwave absorbent material. Radiation is provided by a microwave source 12 which is driven by a transformer 13 in dependence upon operation of a control switch 14. Power is fed from a mains input socket 15 via the switch 14 in dependence upon control apparatus 16 which serves to control operation of the switch 14. Control is effected by means of a control loop including a microwave sensor 17 which is positioned on the furniture 10 to be irradiated. The level of microwave energy which passes through the furniture 10 is sensed by the sensor 17 and the period of exposure to the radiation is determined accordingly by the control apparatus which serves to operate the switch when sufficient radiation has been sensed by the sensor 17.

Additionally remote control of the magnetron is effected by control apparatus which comprises a transmitter/receiver 18 arranged in mutual communication with a transmitter/receiver 19 which forms a part of apparatus operatively associated with the microwave source 12. Signals from the control apparatus may be arranged to effect the same functions as hereinbefore described with reference to Figure 1 and additionally the loop between the transmitter/receivers 18 and 19 may be used to determine the distance between the apparatus and provide an "interlock" function so that the microwave source 12 cannot be energised unless the control apparatus 18 is spaced a predetermined distance (at least) from the microwave source 12.

Various modifications and design changes may be made to the arrangement just before described without departing from the scope of the invention, and for example the manner in which the communication link between the transmitter/receivers 18, 19 is effected may comprise using infrared radiation, ultrasonic radiation or microwave radiation. Additionally, any known form of microwave radiator may be used with control apparatus as well known to those versed in the microwave oven and associated microwave arts.

Claims

1. Pest control apparatus comprising a microwave radiation source contained in a first housing, which source is adapted and arranged to be controlled remotely by control apparatus contained in a second housing, and microwave shielding means which serves to protect personnel from microwave radiation emanating from the said source.

2. Apparatus as claimed in Claim 1, wherein the control apparatus is linked for control purposes to the microwave radiation source by means of a cable which serves as a power/communication link, or by means of a communication link which uses radiation such as ultrasonic, infrared, or radio frequency radiation as an information carrier.

3. Apparatus as claimed in Claim 2, wherein the communication link comprises a transmitter which forms a part of the control apparatus and a receiver operatively associated with and contained in the same housing as the microwave source.

4. Apparatus as claimed in Claim 2, wherein the communication link comprises a transponder arrangement including a first transmitter/receiver which is contained in the first housing with the microwave source and which is arranged in communication with a second transmitter/ receiver which forms a part of the control apparatus, thereby to define a feed back control loop by means of which predetermined control of the said source is effected.

5. Apparatus as claimed in Claim 4, wherein the feed back control loop includes or forms a part of a distance sensor circuit responsive to the distance between the control apparatus and the said microwave source for operating an "interlock" by means of which the said source is switched off so that it cannot be energised to radiate microwave energy unless the control apparatus is spaced away from the said source by more than a predetermined distance.

6. Apparatus as claimed in any preceding claim, wherein operation of the said microwave source is controlled in dependence upon a personnel sensor which serves to detect the presence of personnel within a predetermined distance of the source and which provides a signal in dependence upon which the said source is operationally inhibited.

7. Apparatus as claimed in Claim 6, wherein the personnel sensor is responsive to infrared radiation.

8. Apparatus as claimed in any preceding claim, wherein the microwave radiation source is adapted and arranged to form a part of an energy control loop, including a sensor responsive to radiation from the said source, or responsive to an effect produced by this radiation for producing a feed back control signal which serves to limit the time for which the source is energised.

9. Apparatus as claimed in Claim 8, wherein the sensor is a microwave radiation sensor placed and located so as to sense the radiation produced at a predetermined location adjacent to an article when irradiated.

10. Apparatus as claimed in Claim 8, wherein the sensor is a temperature sensor which is used to sense the heating effect produced by the source in or on an article to be irradiated.

11. Apparatus as claimed in Claim 1, and substantially as hereinbefore described with reference to the accompanying drawings.