GB2097595A - Television aerials - Google Patents

Abstract

An indoor television aerial has a base 10 from which extends a post 12 on which is pivotally mounted a combined boom 17, 18 and connecting box 28, 29 for a dipole 43, the boom and connecting box being formed from two snap-interconnectible mouldings and the mouldings having respective sockets for a reflector 21 and elements 25, 26, 27 of the aerial. <IMAGE>

Description

SPECIFICATION Television aerials This invention relates to aerials for receiving television signals over a range of frequencies and being of small size so as to be suitable for indoor use. Such aerials are usually referred to as set top aerials although of course they are not necessarily to be placed on the television set itself.

The set top aerial of the kind with which the invention is concerned has a base from which projects a post at the top of which is carried a boom.

Set top aerials are usually of two kinds namely one in which the boom carries a dipole of loop form, a reflector and a number of elements and the other has no dipole or reflector but has elements only. The invention is concerned with the first type of aerial.

The boom has a number of spaced projecting elements of length and spacing to enable signals of a range of frequency to be picked up the elements being arranged in parallel with the reflector and at the opposite side of the dipole. The dipole is furthermore electrically connected to the television set through a flexible cable which is usually of the coaxial type.

The object of the invention is to provide a set top television aerial which is efficient in operation but which is inexpensive to produce.

According to the invention there is provided a television aerial having a base, a post projecting from the base and supporting a boom which incorporates a dipole connecting box, the boom being formed from two mouldings securable together at a position to define between them said dipole connecting box and the respective mouldings having means for supporting a reflector and elements for the aerial.

The invention will now be described by way of example with reference to the accompanying drawngs in which, Figure 1 is a perspective view of a television set top aerial constructed in accordance with the invention, Figure 2 is an end elevation view of the aerial, Figure 3 is an end elevation view of the base and post of the aerial, Figure 4 is a plan view of the boom of the aerial, Figure 5 is a cross-sectional view of one of the components making up the boom of the aerial, Figure 6 is an end elevation view of the component of Figure 5, Figure 7 is and end elevation view of the other component making up the boom and, Figure 8 is a cross-sectional view of the component of Figure 7.

As seen in Figure 1 the television aerial is a relatively small size and is therefore suitable for mounting on the top of a television set or other appropriate surface indoors. The aerial has a rectangular base 10 which in this example is a plastics moulding with a detachable underneath part (not shown). The base 10 incorporates a socket 11 to accept an upright post 12. This is of cruciform cross-section and at its upper end an integral bearing structure 13 is formed. This is shown also in Figure 3 and from that view it can be seen to have an aperture having a part circular upper portion 14 and a lower portion 15 of greater vertical length than the diameter of the circular portion but of the same width.

The part circular portion 14 is more than 1800 so that there are defined two projections 16 which served to define the boundary between the two zones 14 and 15.

The post 12 is engaged in the socket 11 of the base 10 by location of the ends of the cruciform parts of the post in respective notches in the socket to prevent rotation of the post relatively to the base.

Mounted in the bearing structure 13 is a boom.

This is formed from two plastics mouldings to which further reference will be made and it takes the form of a generally elongated cruciform cross-section member held substantially horizontally at the top of the post 12. The two mouldings are identified by numerals 17 and 18 respectively the moulding 17 being shorter than the moulding 18. The moulding 17 is as previously mentioned of generally cruciform cross-section but has at its outer end an integral portion 19 with a hole extending laterally of the length of the moulding 17. Through the hole passes a reflector 21 in the form of a straight wire. Such reflector extends equally at opposite sides of the boom.

The other moulding 18 is also of cruciform crosssection being coplanar with the cruciform section of the moulding 17. There are three spaced integral formations 22,23,24 similar to the formation 19 for the reflector. In each formation is engaged an element 25, 26, 27 but these are of different lengths the longer being nearer to the reflector and the shorter being at the outer end of the boom.

The two mouldings of the boom are interconnected at a position at which a dipole connecting box is formed. The dipole connecting box has a cover part 28 which is formed integrally with the moulding 17 and an enclosure part 29 which is formed integrally with the moulding 18. Adjacent to the cover part 28 the moulding 17 has a cylindrical portion 31 seen particularly in Figure 4. This is of a size to engage in the part circular portion of the hole in the bearing structure 13 at the top of the post 12.

The lower larger opening portion 15 is of a size to accept the end of the boom moulding 17 without the reflector 21 fitted therein and by manipu;ation and it is possible over the cruciform area to engage the moulding 17 in the upper part circular portion 14 of the bearing structure and then to move the moulding lengthwise so that the cylindrical portion 31 engages in such bearing portion. By this means it is possible to adjust the boom angularly relatively to the post.

As seen in Figures 5, 6,7 and 8 the dipole box is generally rectangular. The cover 28 being formed integrally on the end of the moulding 17 has a flange 32 with two pairs of oppositely aligned gaps 33, 34 and on the outside of the flange at the two opposite longer sides there are pairs of pine tree like integral projections 35. In the cover there is an access hole 36 for entry of a cable for connection to the dipole as will be described.

The portion of the box formed on the moulding 18 also has a peripheral flange but of a shape to enclose the flange 32 of the other part of the box. There are furthermore two pairs of opposite slots 37,38 which are narrower than the slots 33,34 in the other part.

The slots 38 furthermore are extended inwardly into integral connector blocks 39 with side entry openings 41. There are pine tree like recesses 42 in the peripheral wall to co-operate with the projections 35 on the other part.

As shown in Figure 1 a dipole 43 is engaged in the dipole connecting box. This is formed as a rectangular loop made from flat strip having two ends engaged in the respective connecting blocks 39 entering through the side of the dipole connecting box through the slots 38. Opposite the two ends a continuous length of the dipole loop passes through the slots 37 and 33 in the respective parts of the box.

Within the connector blocks 39 electrical connection is made to the ends of the dipole 43 and these are in turn connected to the cable passing through the access hole 36 in the cover part 28 of the box.

It is to be understood that the boom assembly including the dipole connecting box reflector dipole and elements can befitted onto a base of other form with or without provision for adjustment relatively to the post.

Claims (8)

1. Atelevision aerial having a base, a post projecting from the base and supporting a boom which incorporates a dipole connecting box, the boom being formed from two mouldings securable together at a position to define between them said dipole connecting box and the respective mouldings having means for supporting a reflector and ele mentsforthe aerial.

2. Atelevision aerial as claimed in claim 1 wherein the post has an opening through which the boom passes, the opening and interengaging portion of the boom being shaped to enable the boom to be adjusted about its longitudinal axis between a number of positions.

3. A television aerial as claimed in either of claims 1 and 2 wherein the dipole connecting box and boom are formed from two mouldings with means for snap engaging them together to define the connecting box.

4. A television aerial as claimed in any one of the preceding claims in which the two mouldings define respective pairs of slots to accept and retain a flat strip dipole when the two mouldings are secured together.

5. Atelevision aerial as claimed in claim 4 in which the slots are arranged in aiigned pairs to accept the ends and also, at different locations, the centre section of a flat strip dipole formed into a loop of which both ends are disposed inside the connecting box.

6. Atelevision aerial as claimed in claim 5 wherein the slots for the ends of the dipole terminate in respective sockets having openings to accept wires for connection to the dipole ends.

7. Atelevision aerial as claimed in anyone of the preceding claims wherein the boom moulding portions include integral sockets for a reflector and elements of the aerial.

8. A television aerial substantially as hereinbefore described with reference to and as shown in the accompanying drawings.