Description of the Prior Art DE-A1-34 06 867 describes an optically adjustable di- rection antenna for satellites, the electrical axis of which is adjusted by means of an optical lens system, which is fixedly connected with the antenna.

Abstract of JP-A-9298415 discloses accurate fixing of the direction of a transmission/reception antenna compris- ing a horizontal shaft having rod shaped radiators and wave directors mounted thereto, by means of a laser beam radia- tion device which is fitted to the root of the shaft, a pointing being fixed to the tip of the shaft. The laser beam radiation device emits a laser beam through the point- ing towards the target.

Problem involved Since the prior art devices are connected with the antenna an operator must aim at the target from a position behind the antenna, which makes the adjustment of the di- rection of the antenna difficult for the operator.

Brief Summary of the Invention The purpose of the invention is to overcome the dif- ficulty mentioned above and to make the adjustment in a more rapid and reliable manner the adjustment as a conse- quence thereof being to a minor degree dependent of the op- erator's skill.

Although the method of the invention has been pro- vided particularly for directing an antenna towards another antenna, it will be understood that the method more gener- ally can be used for directing another type of element to- wards a point in the space.

In order to achieve the purpose mentioned above the invention provides a method of the kind referred to which according to claim 1 is characterized in that - an optical sight having a light tunnel is mounted to the plane with the optical axis of the light tunnel per- pendicular to the plane, - the light intercepted by the light tunnel is de- flected perpendicularly to said optical axis to an ocular, - the operator looks through the sight at the ocular and by adjustment of said plane directs the optical axis towards said point in the space, - the sight is demounted from the adjusted plane, and - an element is mounted to the plane having a direc- tional axis thereof perpendicular to the plane.

Further features of the invention are defined in the dependent claims.

Brief Description of the Drawing An illustrative embodiment of the invention will be described below with reference to the accompanying drawings in which FIG 1 is a longitudinal cross sectional view of a red point sight which can be used in working the method of the invention, FIG 2 is a perspective view of the sight combined with a light deflector, FIG 3 is a perspective view of the device shown in FIG 2 mounted to a plane, a coordinate system being laid out in the figure in order to facilitate the explanation of the method.

FIG 4 is a perspective view of an antenna pole with the device shown in FIG 3 mounted to the pole, and FIG 5 is a perspective view of the pole with an an- tenna mounted on the adjusted plane.

Detailed Description of the Invention The sight disclosed in FIG 1 is suitable for use in practising the method of the invention and can be a sight marketed under the trade mark Aimpoint by Aimpoint AB a Swedish company of Malmo, Sweden. The sight comprises a light tunnel formed by an outer tube 10, and an inner tube 11 which is mounted in the outer tube at one end and is fixed at the other end by adjustment means comprising two adjustment screws which enclose a right angle and are screwed radially into the outer tube 10 engaging at their ends the inner tube to allow adjustment of the longitudinal axis of the inner tube in relation to the longitudinal axis of the outer tube as may be necessary in order to adapt the sight to the local conditions where it is used. In said one

end of the inner tube a double lens 12 is provided having a layer 13 between the lenses, and inside the inner tube a light source comprising a light emitting diode 14 is mounted in the focus of lens 12. Layer 13 reflects light in a narrow wave length field corresponding completely or partly to the wave length field in which the light emitting diode emits light. The light emitting diode projects a light beam on layer 13 which reflects the light beam through a face-ground glass plate 15 protecting the light tunnel against humidity and dust and having an anti- reflection layer on the side thereof facing the right end of the light tunnel. The light path is indicated by a dot- and-dash line 16 in FIG 1. The light emitting diode is en- ergized via electronic drive circuitry by a battery mounted in a closed housing 17, FIG 2, integral with the outer tube 10 and having a plug 18 which can be demounted when it is desired to replace the battery. In the Aimpoint sight men- tioned above the light emitting diode 14 emits light in the red field (about 640 nm) which is reflected by layer 13. In other wave length fields including the visable field lens 12 transmits the light. The light emitting diode creates a red light spot, and a person looking through the sight from the right end thereof will see the target area and the red light spot superimposed on the target area as an aiming point. In order to create a light spot the intensity of which is not too feeble and not too intense in relation to the viewed area the current of the light emitting diode can be adjusted by means of a control knob 19 connected to a control circuit.

The sight is combined with a light deflector 20 which is rotatably mounted to the right end of the outer tube 10 of the sight by means of a screw 21 on the deflector, which engages a circumferential groove in tube 10. The deflector has a right-angled prism or inclined mirror which deflects the light intercepted by the sight transversely at right

angles to the optical axis of the sight so that an operator can look through the sight laterally thereof through an ocular 22 on the deflector which can be rotated to bring the ocular to an angular position which is most convenient for the operator. The ocular preferably is provided with a protecting glass which in order to reduce reflection there- from may be coated with an anti-reflecting layer.

Referring to FIG 3 a plate 23 forms the plane which shall be adjusted so that a perpendicular thereof is di- rected towards a specific point in the space. A bracket 24 forming two limbs 25 and 26 at right angles to each other is mounted to the plate 23 at one limb 25 by four screws 27 (one of them is not seen in FIG 3), the other limb 26 pro- jecting perpendicularly from the plate. The outer tube 10 of the sight is provided with an annular holder 28 clamped about the tube by means of screws 29. The holder is engaged with a dove tail rail 30 attached to limb 26 and can be displaced along the rail (the X-axis) and be fixedly con- nected therewith in the desired displaced position by means of a set screw 31.

The optical axis of the sight should be adjusted by means of the adjustment screws mentioned above so that the optical axis of the sight is parallel with the X-axis and is perpendicular to the Y-Z-plane.

In FIG 4 an upstanding slotted antenna pole 32 fix- edly anchored in the ground or on a building or tower structure is shown with a plate 33 which is secured to a holder 34 displaceable along the pole and provided with clamping means 35 for fixedly secure the holder with the plate in a desired displaced position on the pole. Plate 23 is connected with plate 33 by means of three screws 36 ro- tatably mounted in plate 33 and screwed into plate 23 which allow universal adjustment of plate 23. The screws can be replaced by a ball joint with means for locking the ball joint in a desired position.

When the plate 23 is to be adjusted to a position in which a perpendicular to the plane of the plate is directed towards a predetermined point in the space e. g. towards a transmission or reception antenna, the operator looks through the sight at ocular 22 and adjusts plate 23 by means of screws 36 until the red spot is centered on said point e. g. the antenna. Then, the screws are locked in the adjusted position by means of lock nuts or lock glue. The bracket 24 is demounted from the plate 23, and an antenna 37 for reception or transmission, respectively, is fixed to the plate by means of screws preferably screwed into the same holes as screws 27, in a position in which the antenna projects perpendicularly from the plate and the electric axis or main plane thereof coincides or is parallel with the optical axis of the sight as mounted to plate 23 during the adjustment operation described above.

Means can be provided for coarse adjustment of the direction of the antenna supported by plate 23 before the method of the invention as described above is applied.