EP0291268A2

EP0291268A2 - Mountings for telecommunications dishes

Info

Publication number: EP0291268A2
Application number: EP88304208A
Authority: EP
Inventors: Norman Albert Cooper
Original assignee: VARITRACK DBS Ltd
Current assignee: VARITRACK DBS Ltd
Priority date: 1987-05-11
Filing date: 1988-05-10
Publication date: 1988-11-17
Also published as: GB2205446A; GB8811155D0; GB2205446B; EP0291268A3

Abstract

A dish mounting includes a base which is attached to a wall or other structure (11), a frame or chassis (13) which can be swung about a vertical axis relative to the base and a dish (10) appropriately carried by the frame or chassis. Releaseable clamping means are provided for securing the frame or chassis in a position in which the dish faces due south and the dish itself is pivotable relative to the frame or chassis about first and second spaced fixing points (14, 15). One of the fixing points is adjustable, by means of a screw-threaded rod (16), towards and away from the base and the other fixing point incorporates a hinge to allow the dish to move, in use, as the said one fixing point is moved towards and away from the base.

Description

Background to the Invention

This invention relates to a mounting for a telecommunications dish, the mounting being fixed, in use, to a wall, chimney or other supporting structure and comprising base means intended to be screwed, bolted or otherwise pinned substantially immovably to the supporting structure and a frame or chassis projecting from the base means and incorporating holding means for holding the dish in the required attitude. Such a mounting is hereinafter referred to as a mounting of the kind specified.
One form of mounting of the kind specified is disclosed in European patent specification number 0038788.
There is now a considerable growth in the use of such dishes. They are normally mounted on the outside wall of a house or other building inside which the television receiver is situated. The design of the dish mounting has hitherto received little detailed attention, but it is clearly crucial to the efficient working of the dish.
With the planned increase in the number of satellites from which television programmes and other communications can be received, it is clearly desirable that provision should be made whereby a dish can be efficiently and accurately installed at the required attitude and it is accordingly an object of the present invention to provide an improved mounting for this purpose.

Summary of the Invention

According to the invention a mounting of the kind specified is characterised in that:-

(a) the frame or chassis can be swung about a vertical axis relative to the base means,
(b) releaseable clamping means are provided for securing the frame or chassis in the required angular position relative to the base means,
(c) the dish is pivotable relative to the frame or chassis about first and second spaced fixing points,
(d) one of the fixing points is adjustable towards and away from the base means and,
(e) the other fixing point incorporates a hinge to allow the dish to move, in use, with said one fixing point as that fixing point is moved towards and away from the base means.

Such a mounting enables the installer of satellite-tracking equipment to overcome difficult locations off the southern polar satellite arc whilst still being able to make the critical adjustments that are required. The ideal location for a satellite-tracking dish fixed to a wall is for the wall to be facing due south. However, a mounting embodying the invention enables the dish to be mounted on the side or end walls of houses which do not face due south. The south-facing orientation of the dish can then be obtained by locking the frame or chassis to the base means via the releaseable clamping means when the frame or chassis has been swung into the appropriate attitude to make the dish face due south.
The base means preferably incorporates at least two spaced points through which are passed the screws or other means pinning it to the supporting structure. The base means may include two portions which are inclined orthogonally relative to one another and each of which is adapted to be screwed, bolted or otherwise pinned to the supporting structure. Such a base means with orthogonally inclined portions may be designed for attachment to a chimney and each of the two portions then preferably terminates in an eyelet structure for connection of a flexible connector element which is intended to extend around the chimney so that the base means can be lashed firmly in position on the chimney.
By providing a base means which, in one form, is specifically intended to be attached to a chimney, it is possible to mount the dish on substantially the highest point of a building and thereby reduce the possibility of the line of sight from the satellite to the dish being obstructed by an adjacent building.
The holding means for the dish may include a mounting element to which, in use, the dish is attached at a number of spaced positions, the mounting element being connected to the frame or chassis at said first and second fixing points and a variable length support extending between the frame or chassis and the mounting element at a position spaced from said first and second fixing points.
By being spaced from the first and second fixing points, the variable length support provides a three-point connection between the mounting element and the frame or chassis. This thus assists in maintaining the stability of the dish. Where the mounting is located at a position which is readily accessible, the variable length support can be used for adjustment of the orientation of the dish so that, if the user so wishes, he can readily re-direct the dish from a position in which it is located to receive communications from one satellite to a position in which it is correctly oriented to receive transmissions from another satellite.

Brief Description of the Drawings

Figure 1 is a side view of a satellite dish mounted on a chimney,
Figure 2 is a side elevational view of the mounting and dish, but excluding the L.N.B.,
Figure 3 is a plan view of the mounting of Figure 2 but excluding the dish and the manual actuator,
Figure 4 is a plan view of part of the mounting showing its attachment to the chimney,
Figure 5 is a side view showing the mounting of a reflector board including an offset dish on a wall,
Figure 6 is a plan view of the mounting shown in Figure 5 excluding the reflector board and the manual actuator,
Figure 7 is a front view of the mounting shown in Figure 6, and,
Figure 8 is a side view of a mounting for a reflector board including an offset dish for use close to the equator.

Description of the Preferred Embodiments

Referring firstly to Figures 1 to 4, these show a mounting for a prime focus satellite tracking dish 10 which is intended to be attached to a chimney 11. The mounting comprises a base 12 and a frame or chassis 13 projecting from the base 12. In use, the satellite tracking dish 10 is held at respective upper and lower fixing points 14 and 15 on the frame 13 and pivots about the axis defined by these fixing points 14 and 15 as it tracks a satellite, such tracking of the satellite being effected either under the control of a motor or under the control of a manual actuator 16.
The base 12 includes two portions 17 and 18 (see Figure 3) which are inclined orthogonally to one another. Each portion 17 and 18 includes upper and lower horizontal box- section frame elements 17A, 17B, 18A and 18B respectively, the upper and lower elements of each portion being interconnected by a vertical metal strut 19, 20. The two portions 17 and 18 are connected together by nut and bolt mechanisms 21 which can be tightened so as to lock the two portions 17 and 18 in the required position of adjustment.
The horizontal box- section elements 17A, 17B, 18A and 18B each terminate in cut-outs 22 which, as described below with reference to Figures 1 and 4, enable the mounting to be lashed in position on the chimney 11. Each of the horizontal box- section elements 17A, 17B, 18A and 18B is formed with an elongated slot 23 and the vertical struts 19 are each formed with apertures 24. The slots 23 and apertures 24 serve to receiving fixing screws for attachment of the base 12 to the chimney stack, the base 12 being positioned relative to the chimney stack 11, as shown in Figure 4, so that the junction between the two portions 17 and 18 of the base 12 is at a corner of the chimney stack 11.
The horizontal box- section elements 18A and 18B of portion 18 of the base 12 each carry a mounting plate 25 which is welded to the associated horizontal element 18A or 18B, the two mounting plates 25 each being drilled to provide a generally central aperture and the two apertures being disposed in register to define an axis which, in use, is disposed vertically. The frame or chassis 13 is arranged for pivotal movement relative to the base 12 about this vertical axis. Releaseable clamping means 26, 27 in the form of bolts and lock nuts passed through each of these apertures to attach the frame or chassis 13 to the base 12. The provision of the releasable clamping means 26, 27 enables the frame or chassis 13 to be swung in an arc about said vertical axis relative to the base 12 whilst allowing the user to lock the frame or chassis 13 in an angular position of adjustment at any selected position within the available arc of swing. As shown, the available arc of swing is almost 270 degrees and thus, with the base 12 attached to the chimney stack 11, the user or installer of the equipment can always ensure that the dish 10 is located in the required south-facing orientation.
As shown in Figures 1 and 2, the frame or chassis 13 consists of a box-section steel tube 28, a first steel strip 29 and a second steel strip 30. The steel strip 29 is arranged vertically and is welded at its lower end to the box-section tube 28. At its upper end it is welded to a horizontal portion of the second steel strip 30. A rod 31 is adjustably connected to an upper portion of the strip 30 and carries the upper fixing point 14. The rod 31 includes an externally screw-threaded portion 32 which extends through an elongate slot in the upper portion of the strip 30, the rod 31 being held in position relative to the strip 30, with appropriate provision for adjustment, by means of lock nuts 33 tightened onto said threaded portion 32. By adjusting the positions of the lock nuts 33 on the screw threaded portion 32 of the rod 31, the upper fixing point 14 can be adjusted towards and away from the strip 30 and thus towards and away from the base 12. The box-section tube 28 is connected at its one end to the plate 25 and is provided at its other end with a hinge 34 to which the lower fixing point 15 is attached.
The dish 10 is attached to a carrier ring 35 which is itself carried by the frame or chassis 13 at the spaced fixing points 14 and 15 so that, in use, the hinge 34 allows the lower fixing point 15 to move as the position of the first or upper fixing point 14 is adjusted by axial movement of the rod 31. Hence, when the base 12 has been fixed in position, and the frame or chassis 13 has been set so that it faces due south, the dish 10 can then be tilted upwardly or downwardly so as to direct the dish towards the satellite, such adjustment being effected by movement of the upper fixing point 14.
The carrier ring 35 includes a generally circular frame with spaced apart attachment lugs 36 to which the dish 10 is attached. From the circular frame, there extend upper and lower struts 37 and 39 which are connected respectively to the rod 31 and the hinge 34 at the upper and lower fixing points 14 and 15. The carrier ring 35, and with it the dish 10, can be pivoted relative to the frame or chassis 13 about the common axis of the upper and lower fixing points 14 and 15. These fixing points 14 and 15 include releaseable clamping means in the form of bolts and lock nuts to hold the carrier ring 35 in the desired position of adjustment. The hinge 34 may include a locking pin which is inserted after the position of the upper fixing point 14 has been established, insertion of the locking pin in the hinge 34 serving to prevent further hinging movement of the hinge 34.
The variable length support 16 extends between the box-section tube 28 and one of the lugs 36 on the carrier ring 35. The variable length support 16 includes a rod 39 which is of uniform cross section and is threaded throughout its length. A joint 40 is provided at one end of the rod 39 for connection of the rod 39 to the lug 36 and the joint 40 includes a threaded stub shaft, a yoke and a sleeve which fits over the threaded rod 39 and is held in position on the threaded rod 39 by means of a pair of lock nuts 41. The yoke is free to pivot relative to the sleeve about the axis of a trunnion interconnecting the yoke and the sleeve. The stub shaft is connected to the lug 36 and is fixed in position by means of a lock nut 42 so that a positive but pivotal connection is provided between the variable length support 16 and the carrier ring 15 at a position spaced from the first and second fixing points 14 and 15.
An axially displaceable sleeve 43 is positioned on the threaded rod 39 and is located between a pair of nuts 44 and 45 which, as explained below, can be used as stop members. A further nut 46 is fixed to the free end of the threaded rod 39 and this fixed nut 46 can be engaged by a suitable tool to effect rotation of the rod 39 to cause axial displacement of the sleeve 43 along the length of the rod 39 as a result of the threaded engagement between the thread on the rod 39 and an internal thread of the sleeve 43. The sleeve of the joint 40 has an unthreaded internal bore and thus does not move axially of the rod 39, being held in position axially of the rod 39 between the two lock nuts 41. The sleeve 43 is connected by a universal joint to a stub shaft 47 which passes through aligned bores in the box section element 28 and is fixed against movement relative to the element 28 by means of a lock nut 48 tightened onto a threaded end portion of the stub shaft 47.
As can be seen from Figures 1 and 2, rotation of the rod 39 by means of the fixed nut 46 will cause a variation in the spacing between the sleeve 43 and the sleeve of the joint 40 and hence a variation in the effective length of the arm 16. The arm 16 will thus serve to support the carrier ring 35 and hence the dish 10 in the orientation to which it has been moved and fine adjustment of the orientation of the dish 10 can be effected by rotating the rod 39.
If the dish 10 is to be directed towards a single satellite and it is accordingly required that the dish 10 should be held in a fixed position, the two nuts 44 and 45 will be rotated along the length of the rod 39 so as to bear against the sleeve 43 and thus hold the sleeve 43 positively against movement axially of the rod 39. If, however, it is intended that the dish 10 should be capable of movement from a position directed towards one satellite into a position directed towards another satellite, the two nuts 44 and 45 can be used as stops with the sleeve 43 bearing against one 44 of the nuts when directed towards one satellite and located against the other nut 45 when directed towards the other satellite. The dish 10 can thus be installed by a trained installation engineer, the nuts 44 and 45 appropriately positioned along the length of the rod 39 and then the user of the apparatus can be given simple instructions on how to move the dish from a position facing one satellite into a position facing the other selected satellite. There will be times when the dish 10 and its mountings are installed when only one satellite is available but when the astral location of a planned satellite is known in advance. It is, therefore, possible for an intallation engineer to fit a satellite dish so positioned as to be directed towards an existing satellite but with a built in facility for a user to direct the dish towards the new satellite when it becomes operational. Adjustment of the position of the dish can be effected using an electric drill having a socket attachment for fitting over the fixed nut 46, with final adjustment being effected manually by means of a spanner.
As shown, in particular, in Figures 1 and 4, the mounting so far described is intended to be mounted on a chimney 11 and to be strapped in position on the chimney.
In order to avoid the application of excessive stresses to the chimney, angle-section elements 49 are placed in position at three corners of the chimney 11 with the junction between the two portions 17 and 18 of the base 12 located at the other corner of the chimney, the base being positioned so that the frame or chassis 13 projects from that face of the chimney which is closest to due south. Two cords 50 are passed around the chimney stack and terminate in eye bolts which are connected to the base 12 utilizing the cutouts 22.
The dish 10 shown in Figure 1 is a prime focus dish and has an L.N.B. 51 located at the focus of the dish 10 with the L.N.B. carried by the dish 10 on support arms 52. There will be occasions when, rather than utilise a prime-focus dish, it is more appropriate to use an offset dish configuration such as that shown, for example, in Figures 5 to 7.
Turning now to deal with the embodiment of Figures 5 to 7, this includes two separate brackets 53 which are intended to be attached at spaced positions to a wall 54, each of the brackets 53 being formed with a series of three cut-outs 55 to receive fixing screws or other attachment elements whereby the brackets 53, which together provide a base, can provide for the pivotal mounting of the chassis or frame 56. Each bracket 53 includes a plate portion 57 which, in use, is disposed horizontally and is drilled so as to provide an aperture, the two apertures being aligned and being arranged to receive releaseable clamping means in the form of bolts and lock nuts 58. The arrangement is basically as described above in relation to the embodiment of Figures 1 to 4, the brackets 53 are attached to the wall 54 and then the frame or chassis 56 is mounted in position and is oriented so that, as nearly as possible, it faces due south.
The frame or chassis 56 of the embodiment of Figures 5 to 7 differs somewhat from that shown in Figures 1 to 4, though the principles of construction and operation are basically the same.
The frame or chassis 56 includes a lower or larger diameter tubular element 59 which is connected at its one end to the lower bracket 53 and which is connected at its other end to a hinge 60 which carries a lower fixing point 61 corresponding to the lower fixing point 15 of the embodiment of Figures 1 to 4. The chassis 56 also includes a generally U-shaped tube 62 which has two parallel limbs 63 and 64 (see Figure 6) with the base of the U looped around and welded to the tube 59. A vertical tube 65 is welded at its lower end to the tube 59 and, at its upper end, is welded in position between the two arms 63 and 64 of the tube 62. The free ends of the arms 63 and 64 are interconnected by a mounting plate 66 which is connected by the releaseable clamping means 58 to the upper bracket 53.
The arms 63 and 64 of the U-shaped tube 62 include horizontal and inclined portions and an adjustment plate 67 is carried by the inclined portions of the two arms 63 and 64. This adjustment plate 67 is welded in position and provides a mounting for a pair of externally screw-threaded rods 68, the upper ends of which are connected to a bridge plate 69. The threads of the two rods 68 are coarse threads and nuts 70 are carried on the rods 68, there being a nut 70 on each side of the plate 67. The threaded rods 68 are intended to provide for coarse adjustment of the inclination of the dish 71 which, in this instance, is an offset design with the L.N.B. 72 offset relative to the incident radiation. The coarse adjustment is effected so that the inclination of the dish 71 is appropriate approximately to the particular latitude at which the dish is located. The lengths of the threaded rods 68 may be such as to provide for say ten, twenty or thirty degrees of adjustment so that the same mounting arrangement can be used in, for example, southern Spain as would be used in the north of Scotland with the appropriate adjustment being effected by means of the rods 68.
The bridge plate 69 is formed with an aperture which receives a further threaded rod 73, the rod 73 again carrying a pair of nuts 74, one located above the bridge plate and the other located beneath the bridge plate 69. The thread of the rod 73 is a fine thread whereby fine adjustment of the inclination of the dish 71 can be effected. The threaded rod 73 carries the upper fixing point 75, the function of which corresponds to that of the upper fixing point 14 of the embodiment shown in Figures 1 to 4. The dish 71 is carried on a rectangular carrier frame 76, the dish 71 being in the form of a reflector board which has a housing attached to the carrier frame 76 by screws or like fasteners passed through apertures 77 formed in the frame 76. Whereas the carrier ring 35 of the embodiment of Figures 1 to 4 is connected to the upper fixing point 14 by a strut 37, the carrier frame 76 of the embodiment of Figures 5 to 7 is connected to the upper fixing point 75 by a linkage 78 which includes a pair of plates 79 and 80 interconnected by a releaseable clamping means in the form of a bolt and lock nut 81 so that the link 78 can be inclined relative to the axis of the rod 73.
The carrier frame 76 is connected to the chassis 56 by a manual actuator 82 corresponding to the manual actuator 16 of the embodiment shown in Figures 1 to 4, the actuator 82 being used in the same way as the actuator 16 to adjust the orientation of the dish 71. As described previously with reference to the actuator 16, the actuator 82 includes a pair of block nuts 83 and 84 which can be used as stops to set the dish 71 in the positions appropriate to particular satellites.
As with the embodiment of Figures 1 to 4, the upper and lower fixing points 75 and 61 of the embodiment of Figures 5 to 7 provide for variation in the orientation of the dish. The upper fixing point 75 can be moved with either coarse or fine adjustment towards and away from the U-shaped tube 62 to vary the inclination of the dish 71 and the hinge 60 enables the lower fixing point 61 to effect the required movements. The hinge 60 may again include a locking pin which, on insertion, locks the hinge 60 in the position in which it has been set.
Turning next to Figure 8, this shows an embodiment similar to that of Figures 5 to 7 except that, whereas the embodiment of Figures 5 to 7 is intended for use primarily at latitudes between forty degrees north and sixty degrees north, the embodiment of Figure 8 is intended for use in latitudes within thirty degrees of the equator. The majority of the parts of the embodiment of Figure 8 are identical to that of Figures 5 to 7 and the same reference numerals are thus used to indicate corresponding parts. Thus, there is an offset dish 71 carried on a chassis 56 mounted on a pair or brackets 53 intended to be mounted on a wall 54 in a position such that access can readily be obtained to the manual actuator 82, a tool 85 being provided to enable a user to adjust the inclination of the dish 71 between the positions defined by the stop members 83 and 84.
The chassis 56 includes a vertical tube 65, a U-shaped tube 62, as for the embodiment of Figures 5 to 7, and a larger diameter tube 59 though the geometry of the chassis 56 differs from what is shown in Figure 5 because of the different latitude in which the dish 71 is to be used. There is again provision for both coarse and fine adjustment of the inclination of the dish by means of the threaded rods 68 and 73 and there are again first and second fixing points 75 and 61 which provide for the same mode of adjustment as has been described above in detail in relation to the embodiment of Figures 5 to 7.
In each of the embodiments shown in the drawings, the dish is pivotable about the common axis of the first and second fixing points by means of the manual actuator. In, however, an alternative arrangement (not shown in the drawings) the manual actuator is replaced by an electric motor which has its output shaft connected to the dish carrier and is arranged, on actuation, to move the dish.

Claims

1. A mounting for a telecommunications dish of the kind which is fixed, in use, to a wall, chimney, or other supporting structure and comprises base means intended to be screwed, bolted or otherwise pinned substantially immovably to the supporting structure and a frame or chassis projecting from the base means and incorporating holding means for holding the dish in the required attitude, characterised in that:-

(a) the frame or chassis can be swung about a vertical axis relative to the base means,

(b) releaseable clamping means are provided for securing the frame or chassis in the required angular position relative to the base means,

(c) the dish is pivotable relative to the frame or chassis about first and second spaced fixing points,

(d) one of the fixing points is adjustable towards and away from the base means, and

(e) the other fixing point incorporates a hinge to allow the dish to move, in use, with said one fixing point as that fixing point is moved towards and away from the base means.

2. A mounting according to claim 1, characterised in that the base means includes two portions which are inclined orthogonally relative to one another and each of which is adapted to be screwed, bolted or otherwise pinned to the supporting structure.

3. A mounting according to claim 2, characterised in that each of the two portions terminates in an eyelet structure for connection of a flexible connector element which is intended to extend around a chimney.

4. A mounting according to claim 1, characterised in that the holding means for the dish includes a mounting element to which, in use, the dish is attached at a number of spaced positions, the mounting element being connected to the frame or chassis at said first and second fixing points.

5. A mounting according to claim 4, characterised in that a variable length support extends between the frame or chassis and the mounting element at a position spaced from said first and second fixing points.

6. A mounting according to claim 5, characterised in that the variable length support includes an externally screw-threaded rod which passes through an internally threaded sleeve carried by the frame or chassis.

7. A mounting according to claim 6, characterised in that the threaded rod carries stop means arranged to engage the sleeve at limiting positions of the travel of the dish.

8. A mounting according to claim 1, characterised in that the means for effecting adjustment of the one fixing point comprises a screw-threaded rod which can be locked in a desired position of adjustment relative to the frame or chassis.

9. A mounting according to claim 1, characterised in that means are provided for effecting both coarse and fine adjustment of the position of said one fixing point.

10. A mounting according to any one of the preceding claims, characterised in that the dish is a prime focus dish as shown in Figures 1 to 4, or that the dish is an offset dish as shown in Figures 5 to 7 or Figure 8 of the accompanying drawings.