GB1590937A - Waveguide for connecting radio apparatus to aerials - Google Patents

Description

(54) WAVEGUIDE FOR CONNECTING RADIO APPARATUS TO AERIALS (71) We, RIVA CALZONI S.p.A. an Italian Joint Stock Company, of 34, Via Stendhal, Milan, Italy, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a waveguide adapted to assume an extended shape and a shortened shape.

A waveguide of the present invention is useful in all cases in which a signal receiving and/or transmitting aerial or aerial array is mounted on a support which may have, for example, to be raised and lowered in relation to a base, whether fixed or mobile where the interior of the base may have to be used in some way, for example, for housing radio apparatus to be connected to the aerial by way of said waveguide.

It is known to use a one piece waveguide in cases of use as described above, the length of the waveguide being equal to the maximum extension reached by the aerial support. Thus, when the aerial support is in the retracted position an important portion of the waveguide is necessarily located inside the fixed or mobile base, in the space immediately below the bearing platform of the aerial support.

This gives rise to the disadvantage that adequate protective means have to be provided around the portion of waveguide which lies within the base and further the portion of the waveguide within the base constitutes an obstruction and reduces the amount of space below the bearing platform.

It is an object of the present invention to provide a waveguide for aerials mounted on supports which can be extended or retracted in relation to their base, whether fixed or mobile, which will not constitute an obstruction inside said base when the aerial support is in the lowered or retracted position.

The problem underlying the invention is that of providing a waveguide which can be extended and retracted without any impairment of its functioning powers as regards the quality and strength of the signal which it transmits.

According to the present invention there is provided a waveguide for connecting radio apparatus to an aerial or aerial array which is mounted on an extensible and rectactable support comprising a telescopic system for extending and retracting the support, the waveguide comprising a first hollow section arranged to be connected at one end to the aerial or aerial array, the opposite end of said first section being free and bent at an angle with respect to the longitudinal axis of said first section, and a second hollow section arranged to be connected at one end to the radio apparatus, the opposite end of said second section being free and bent at an angle with respect to the longitudinal axis of said second section, wherein the opening in the free end of said second section is turned towards the opening in the free end of said first section, said first and second sections being fixed to respective elongate support members engaging for sliding with respect to one another in the longitudinal direction, such that when the support members are fully extended the opening of the free end of the first section is exactly facing and in contact with the opening in the free end of the second section, one of said support members being arranged to be connected to the extensible and retractable aerial support while the other support member is arranged to be connected to a point which is stationary with respect to movements parallel to its longitudinal axis.

An embodiment of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates schematically an aerial installation with a support which can be extended and retracted with respect to a fixed base, in the retracted position; Figure 2 illustrates schematically the installation of Figure 1 with the aerial in the extended position; Figure 3 shows a longitudinal section of a waveguide of the present invention in the retracted position, taken along the line III- III of Figure 5; Figure 4 shows a longitudinal section of the waveguide in the extended position, taken along the line III--III of Figure 5; and Figure 5 shows a transverse section of the waveguide taken along the line V-V of Figure 3.

Referring to the drawings, and in particular to Figures 1 and 2, the reference 1 indicates a generic fixed base at the top of which is installed an aerial 2.

The aerial 2 may, for example, be of the parabolic type, rotating in conventional manner around the vertical axis of its support 3 through means which in themselves are known and conventional.

Instead of being fixed, the base 1 may be mobile, constituted, for example, by a generic vehicle. The support 3 is mounted on the end of a hydraulic raising and lowering system of the telescopic type comprising cylinders 4 and 5. The unit made up of the cylinders 4 and 5, in itself conventional, when in the retracted position shown in Figure 1, is accommodated in a space 6 located immediately above a space 7 in the base 1 in w ich radio apparatus 8 is housed. The radio appa ratus 8, which need not be housed in the space 7, is connected to the aerial 2 by way of conductors 9 which are shown schematically and by way of example.

Inside the pair of cylinders 4 and 5 the driving elements for rotation of the aerial 2 extend, in known manner. These elements are conventional and since they are not essential to the understanding of the present invention they will be described only partially.

Also within the telescopic unit for the raising and lowering of the support 3 of the aerial 2 is a waveguide, the function of which is to connect the aerial 2 to the terminal 9a of the conductors 9.

Referring to Figures 3 to 5, the waveguide comprises a first section 10 having, for example, a hollow rectangular section, fixed by means of anchorages 11, conventional in themselves, to the internal wall of a support member in the form of a hollow cylinder 12.

The cylinder 12 is mechanically connected, by way of its extension 12b, to the support 3 of the aerial 2 so as to be able to follow the axial movements for raising and lowering said support. The end 13 of said first section 10 of the waveguide is connected rigidly, by way of a joint 14, to a portion 15 of the waveguide connecting to the aerial 2.

The opposite end 16 of the section 10 of the waveguide, on the other hand, is bent at an angle with respect to the longitudinal axis of said section 10; in particular it is bent at right angles so as to bring the opening 16a in the end 16 into a plane parallel to the longi stQdinal axis of the section 10.

s can be seen from Figures 3 and 4, the end 13 of the section 10 of the waveguide is Xft$dover a distance from the joint 14 so as to bring the section 10 of the waveguide from a position co-axial with the cylinder 12 into an eccentric position near to the internal wall of said cylinder 12.

The waveguide also comprises a second section 17, having a transverse section which is the same as that of the first section 10. The end 18 of the second section 17 is connected, through a conventional joint 19 and a rotating joint also conventional and not illustrated, to the conductors 9 connected to the radio apparatus 8.

Said second section 17 of the waveguide is fixed, along its longitudinal extent, to a support member in the form of a rod 20. Said rod 20 can slide telescopically within the interior 12a of the cylinder 12 to which the first waveguide section 10 is fixed. At its end 21 the rod 20 is substantially stationary with respect to movements of translation parallel to its longitudinal axis but is connected to driving elements conferring rotary motion around its longitudinal axis.

As can be seen from Figures 3 and 4, the end 18 of the waveguide section 17 is curved for a certain distance from the joint 19 so as to bring the longitudinal axis of said section into an eccentric position with respect to the longitudinal axis of the supporting rod 20.

The opposite end 22 of the section 17 is bent over at an angle, in particular at right angles, in the same way as the end 16 of the first section 10, so that the opening 22a is turned towards the opening 1 6a of the first section.

Referring, now, to Figure 5 it will be seen that the rod 20 engages for sliding with the internal wall of the hollow cylinder 12 which, in particular, has a circular transverse section, by means of a plurality of longitudinal splines 23. The splines 23 are formed by bars with a trapezoidal section, solid with said rod 20, and inserted in corresponding grooves 24 formed on the outer periphery of the rod 20.

In addition, the rod 20, which is situated inside the cylinder 12, is provided with a longitudinally extending recess 25 which extends substantially parallel to the waveguide section 10, and with a longitudinally extending recess 26 diametrically opposite the recess 25. The second waveguide section 17 is fixed in the recess 26.

In order to effect the rotation of the whole unit formed by the cylinder 12 and the rod 20, whilst still allowing axial movement of the cylinder 12, the internal rod 20 is connected at its end 21 to an auxiliary cylinder 27 which receives the cylinder 12 in its interior.

The cylinder 12 has two longitudinally extending grooves 28 and 29 formed in its outer periphery diametrically opposite one another. Corresponding longitudinally extending ribs 30 and 31 which are solid with the internal wall of the auxiliary cylinder 27 slidingly engage in respective ones of the grooves 28 and 29. The ribs 30 and 31 are formed at the level of the end 27a of the auxiliary cylinder 27.

Whereas the grooves 28 and 29 extend over the entire length of the cylinder 12, the ribs 30 and 31 extend only for a certain distance from the mouth of the end 27a of the auxiliary cylinder 27. As can be clearly seen in Figures 3 and 4, the grooves 28 and 29 are closed at each end thereof and form stops against which the ribs 30 and 31 abut in both the retracted position (Figure 3) and the extended position (Figure 4) of the waveguide.

From the above description and by reference to the accompanying drawings it can be seen that when the support 3 of the aerial 2 is raised by means of the telescopic hydraulic system constituted by the cylinders 4 and 5 the cylinder 12, which is inserted coaxially inside the cylinders 4 and 5 and fixed at one end to the support 3, is moved axially.

During this movement the cylinder 12 moves out of both the internal rod 20 and the auxiliary cylinder 27.

There is thus a reciprocal longitudinal displacement between the waveguide sections 10 and 17 which are solid with the mobile cylinder 12 and the fixed rod 20 respectively.

At the end of the raising movement, when the support 3 of the aerial 2 has reached the required position, the ends 16 and 22 of the sections 10 and 17 come into a position facing one another with the openings 1 6a and 22a exactly communicating with one another. In this position (Figure 4) the two sections 10 and 17 constitute a single waveguide capable of transmitting signals from and to the aerial 2.

When the support 3 is lowered the movements are the reverse of those described above and the waveguide sections 10 and 17 return to the retracted position which can be seen in Figure 3. Thus, the waveguide makes it possible to raise and lower the aerial and connects the aerial to the radio apparatus, when the aerial is in its raised, operating position. The assembly is relatively short and is limited substantially to the length of the telescopic hydraulic system for raising and lowering said aerial.

From this there follows the further advantage inherent in the removal of obstructions beneath the aerial raising system conferring the benefit of a larger space which is available either for operators or for the radio apparatus.

WHAT WE CLAIM IS: 1. A waveguide for connecting radio apparatus to an aerial or aerial array which is mounted on an extensible and retractable support comprising a telescopic system for extending and retracting the support, the waveguide comprising a first hollow section arranged to be connected at one end to the aerial or aerial array, the opposite end of said first section being free and bent at an angle with respect to the longitudinal axis of said first section, and a second hollow section arranged to be connected at one end to the radio apparatus, the opposite end of said second section being free and bent at an angle with respect to the longitudinal axis of said second section, wherein the opening in the free end of said second section is turned towards the opening in the free end of said first section, said first and second sections being fixed to respective elongate support members engaging for sliding with respect to one another in the longitudinal direction, such that when the support members are fully extended the opening of the free end of the first section is exactly facing and in contact with the opening in the free end of the second section, one of said support members being arranged to be connected to the extensible and retractable aerial support while the other support member is arranged to be connected to a point which is stationary with respect to movements parallel to its longitudinal axis.

2. A waveguide as claimed in Claim 1, wherein the free ends of said first and second sections are bent at right angles with respect to the longitudinal axis of the respective section.

3. A waveguide as claimed in Claim 1 or 2, wherein said support member arranged for connection to the extensible and retractable aerial support is provided, on its outer surface, with a pair of grooves extending longitudinally over the entire axial extension of said support member, and wherein the other support member is rigidly fixed to the interior of an elongate tubular auxiliary member, said tubular auxiliary member being provided with a pair of longitudinally extending ribs projecting from its internal surface and in sliding engagement with said pair of grooves.

4. A waveguide as claimed in Claim 3, wherein one of said support members is a hollow cylinder and the other support member is accomodated telescopically in the interior of the first one; and wherein a plurality of sliding splines are distributed around the outer periphery of the internal support member and connected to the internal support member.

5. A waveguide as claimed in Claim 4, wherein said tubular auxiliary member and said telescopic support members are rotatable, and driving means being provided to impart rotary motion through said tubular auxiliary members.

6. A waveguide as claimed in any preceding Claim, wherein the ends of said first and second sections opposite said free ends are connected to the respective support members in an axial position with respect thereto, said ends being curved, over a certain distance, from their connection to the respective support member, in order to bring the axial extenxion of each section into an eccen

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. formed at the level of the end 27a of the auxiliary cylinder 27. Whereas the grooves 28 and 29 extend over the entire length of the cylinder 12, the ribs 30 and 31 extend only for a certain distance from the mouth of the end 27a of the auxiliary cylinder 27. As can be clearly seen in Figures 3 and 4, the grooves 28 and 29 are closed at each end thereof and form stops against which the ribs 30 and 31 abut in both the retracted position (Figure 3) and the extended position (Figure 4) of the waveguide. From the above description and by reference to the accompanying drawings it can be seen that when the support 3 of the aerial 2 is raised by means of the telescopic hydraulic system constituted by the cylinders 4 and 5 the cylinder 12, which is inserted coaxially inside the cylinders 4 and 5 and fixed at one end to the support 3, is moved axially. During this movement the cylinder 12 moves out of both the internal rod 20 and the auxiliary cylinder 27. There is thus a reciprocal longitudinal displacement between the waveguide sections 10 and 17 which are solid with the mobile cylinder 12 and the fixed rod 20 respectively. At the end of the raising movement, when the support 3 of the aerial 2 has reached the required position, the ends 16 and 22 of the sections 10 and 17 come into a position facing one another with the openings 1 6a and 22a exactly communicating with one another. In this position (Figure 4) the two sections 10 and 17 constitute a single waveguide capable of transmitting signals from and to the aerial 2. When the support 3 is lowered the movements are the reverse of those described above and the waveguide sections 10 and 17 return to the retracted position which can be seen in Figure 3. Thus, the waveguide makes it possible to raise and lower the aerial and connects the aerial to the radio apparatus, when the aerial is in its raised, operating position. The assembly is relatively short and is limited substantially to the length of the telescopic hydraulic system for raising and lowering said aerial. From this there follows the further advantage inherent in the removal of obstructions beneath the aerial raising system conferring the benefit of a larger space which is available either for operators or for the radio apparatus. WHAT WE CLAIM IS:

1. A waveguide for connecting radio apparatus to an aerial or aerial array which is mounted on an extensible and retractable support comprising a telescopic system for extending and retracting the support, the waveguide comprising a first hollow section arranged to be connected at one end to the aerial or aerial array, the opposite end of said first section being free and bent at an angle with respect to the longitudinal axis of said first section, and a second hollow section arranged to be connected at one end to the radio apparatus, the opposite end of said second section being free and bent at an angle with respect to the longitudinal axis of said second section, wherein the opening in the free end of said second section is turned towards the opening in the free end of said first section, said first and second sections being fixed to respective elongate support members engaging for sliding with respect to one another in the longitudinal direction, such that when the support members are fully extended the opening of the free end of the first section is exactly facing and in contact with the opening in the free end of the second section, one of said support members being arranged to be connected to the extensible and retractable aerial support while the other support member is arranged to be connected to a point which is stationary with respect to movements parallel to its longitudinal axis.

2. A waveguide as claimed in Claim 1, wherein the free ends of said first and second sections are bent at right angles with respect to the longitudinal axis of the respective section.

3. A waveguide as claimed in Claim 1 or 2, wherein said support member arranged for connection to the extensible and retractable aerial support is provided, on its outer surface, with a pair of grooves extending longitudinally over the entire axial extension of said support member, and wherein the other support member is rigidly fixed to the interior of an elongate tubular auxiliary member, said tubular auxiliary member being provided with a pair of longitudinally extending ribs projecting from its internal surface and in sliding engagement with said pair of grooves.

4. A waveguide as claimed in Claim 3, wherein one of said support members is a hollow cylinder and the other support member is accomodated telescopically in the interior of the first one; and wherein a plurality of sliding splines are distributed around the outer periphery of the internal support member and connected to the internal support member.

5. A waveguide as claimed in Claim 4, wherein said tubular auxiliary member and said telescopic support members are rotatable, and driving means being provided to impart rotary motion through said tubular auxiliary members.

6. A waveguide as claimed in any preceding Claim, wherein the ends of said first and second sections opposite said free ends are connected to the respective support members in an axial position with respect thereto, said ends being curved, over a certain distance, from their connection to the respective support member, in order to bring the axial extenxion of each section into an eccen

tric position with respect to the longitudinal axis of the respective support member.

7. A waveguide substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.