COVER FOR PARABOLIC DEVICES

Abstract: A shield device for the microwave horns (4) of parabolic aerials to protect the horns against snowfall, icebounding and rainy weather. The shield device comprises an approximately 180 DEG arced cover (1) made of a transparent material arranged around the horns (4) and at a distance from the horns (4). The cover (1) is forming an "umbrella" over the horns (4) and prevent reduction of the signals and thereby the picture quality during bad weather. The cover (1) is on each side connected to a mounting device (2). An underplate (3) is by fastening joints (7) arranged for fastening the mounting device (2) on each side of a bar (5), at the end of which the horns (4) are mounted.

Description: Cover for parabolic devices This invention relates to a shield device for the microwave horns of parabolic aerials. The shield device is especially intended for the horn of parabolic devices having either fixed mounted horns for receiving signals from 1 degree west - 5 degrees east, or possibly motorized horns. The JP patent applications having the publication Nos. 04-111 601, 63-283 204 and 60-105 301 are disclosing covers for protection of the horns against snowfall, icebounding and rainy weather. The covers are rotatable so that snow which have been falling on the upside of the cover will fall off during the rotation of the covers. DE patent 4 116 095 describes a closed tubular protection cap of transparent plastic material having a ventilation aperture at the underside. The object of this invention is to provide a shield device for the microwave horns of parabolic aerials which in addition to the protection of the horns against snowfall, icebounding and rainy weather also shall prevent reduction of the signals at the input to the feedhorn before the microwave horn. It is known among the manufacturers of parabolic aerials that it is just at the input to the feedhorn before the microwave horn that the signals from a satellite is most susceptible during bad weather. Another object of the invention is to provide a shield device which is easy to mount. These objects are achieved according to the invention by the characteristic features of the shield device as disclosed in claim 1. Preferable embodiments of the shield device are stated in the dependent claims. The shield device according to the invention has a simple structure and can be manufactured at low costs. It is forming an "umbrella" over the horns and prevent reduction of the signals and thereby the picture quality during bad weather. The invention will now be described with reference to some preferred embodiments and to the drawings, wherein Fig. 1 shows schematically a shield device with a cover and mounting device, Fig. 2 is an exploded view of an embodiment of the shield device and the elements for the fastening thereof, Fig. 3 shows schematically the shield device on Fig. 2 viewed from the side, Fig. 4 is a plan view of the shield device arranged centric in relation to the horn, and Fig. 5 is a plan view of the shield s device arranged centric in relation to two horns. Fig. 1 of the drawings is showing schematically a shield device according to the invention. The cover 1 is on each side connected to a mounting device 2 and an underplate 3 is by fastening screws 7 arranged for fastening the mounting device 2 o on each side of a bar at the end of which the horns are mounted. The cover 1 is in the form of an approximately 180° arced light conical shell . The cover 1 may also be in the form a part of a cylindrical shell. The cover 1 is made of a transparent plastic material s and arranged around the microwave horns and at a distance from the horns. The cover 1 is "hollow" and forms an "umbrella" over the horns so that the picture quality is not reduced during bad weather. Because the cover 1 is made of a transparent plastic material a possible partly covering of the signal path will not 0 reduce the signals. Fig. 2 of the drawings which is an exploded view is showing an embodiment of the cover 1 and the elements for the fastening thereof to a bar 5 at the end of which the horns 4 are mounted. In this embodiment the cover 1 is in the form of an app- 5 roximately 180° arced part of a cylindrical shell. The cover 1 is on each side connected to a mounting device 2 by screw joints. The mounting device 2 is connected to the bar 5 by means of an underplate 3 and screw joints 7 on each side of the bar 5. The mounting device 2 is connected to the bar 5 in the vicinity of o the end thereof where the horn 4 is mounted. Fig. 3 of the drawings, which is a side view of the embodiment on Fig. 2, is showing the position of the cover 1 over and on the sides of the horn 4. The cover 1 may be adjusted in the same angular position as the horn 4 by means of oblong holes 5 6 in the mounting device 2 for the screw joints to the cover 1. Fig. 4 of the drawings, which is a schematical plan view, is showing the arrangement of the cover 1 centric in relation to the horn 4. Fig. 5 of the drawings, which is a plan view like Fig. 4, is showing the arrangement of the cover 1 centric in relation to two horns 4. It will be appreciated that it may be used other fastening means for the cover 1 than the screw joints used in the s disclosed examples of embodiments. 5 0 5 0

Claims: 4 C l a i m s 1. A shield device for the microwave horns of parabolic aerials, characterized in that the shield device is comprising an approximately 180° arced cover (1) made of a transparent material arranged around the microwave horns (4) and at a distance from the horns ( 4 ) , the cover ( 1 ) is on each side connected to a mounting device (2), an underplate (3) is by fastening joints ( 7 ) arranged for fastening the mounting device ( 2 ) on each side of a bar (5), at the end of which the horns (4) are mounted. 2. A shield device according to claims 1 , characterized in that the cover ( 1 ) is in the form of a part of a light conical shell. 3. A shield device according to claim 1 , characterized in that the cover ( 1 ) is in the form of a part of a cylindrical shell.

Inventors: CHRISTOFFERSEN KJETIL, CHRISTOFFERSEN, KJETIL
Applicants: CHRISTOFFERSEN KJETIL, CHRISTOFFERSEN, KJETIL
Application year: 1999
Main classification: H01Q1
IPC codes: H01Q1