GB2505066A

GB2505066A - Positioning gear, bracket and system having gear segments

Info

Publication number: GB2505066A
Application number: GB201311505A
Authority: GB
Inventors: Mark Stevens; Jonathan Knight
Original assignee: Sub10 Systems Ltd
Current assignee: Sub10 Systems Ltd
Priority date: 2012-06-27
Filing date: 2013-06-27
Publication date: 2014-02-19
Also published as: GB201311505D0

Abstract

A positioning gear, bracket and system comprises first and second gear trains 21, 22 having a common geared body 4 with first and second gear segments 4a, 4b meshing with a first and second driving gears, e.g. worm gears 5, 9. A first connector 7 connects a first member, such as a wall, to a first axis 21a and second connector 8 connects a second member to a second axis 22a. The connectors may comprise an assembly of a mounting plate 7a, 8a and bolts/nuts 7b/8b, although other arrangements are possible. The first and second gear segments 4a, 4b may be formed as arcs having a substantially constant radius or other gear geometries or types could be used. One or more of the first and second driving gears 5, 9 may be resiliently sprung against the respective first and second gear segment 4a, 4b so as to minimise any backlash. Spring resilience may be provided at an interface where the worm gear 5, 9 is bolted to the respective mounting plate 7a/8a.

Description

Positioning Gear, Bracket, and System

Field of the Invention

The present invention relates to a positioning gear, system, assembly and bracket that are particularly applicable to mounting of equipment and apparatus.

Background to the Invention

Mounting of equipment and apparatus is achieved in a number of ways.

Sometimes the equipment will include its own mounting points which are then screwed, bolted or otherwise fixed into place during installation. In other situations, a mounting plate may first be fixed into place and the equipment or apparatus then installed onto the mounting plate. In yet other situations, the equipment or apparatus may be mounted on to a bespoke or generic bracket which is mounted in place.

Where the apparatus or equipment may be mounted in a potentially exposed, external position, the mount or bracket typically is selected so as to be unlikely to fail over the lifetime of the equipment. This typically means that the mount or bracket will be a unitary body so as to avoid failure of joints during exposure to changing weather conditions.

However, there are circumstances where adjustment of the mounting of the equipment either at installation or at a later date is required. In such circumstances, the mount or bracket or the manner in which it is installed or fixed to the equipment must be adjustable. Adjustment may be provided for example, by moveable joints or releasable mount (such as a U shaped bolt positioned around a mast and tightened against a plate by nuts to hold the mount by compression against the mast).

In situations where the equipment may be mounted in an exposed position but nevertheless needs the ability to be adjusted during installation or at a later date, the two requirements conflict. This problem is exacerbated if the mounted equipment must be oriented with any degree of precision.

Statement of Invention

According to an aspect of the present invention, there is provided a positioning gear comprising a geared body having first and second gear segments mounted respectively about first and second axes, the first and second axes being transverse and each of the first and second axes defining a mounting point for mounting the positioning gear.

The geared body preferably comprises a unitary body, although it could be made in parts and assembled.

Each mounting point may comprise a shaft for receiving a pin along the respective axis or it may comprise a post or other member which may optionally be at least partly threaded.

According to another aspect of the present invention, there is provided a positioning bracket, the positioning bracket being adjustably connectable to respective first and second members and comprising: first and second transversely arranged gear trains, the first and second gear trains being separately driveable in respective first and second planes; a first connector to connect the first member to the gear first train and being controllable to permit movement in the first plane with respect to the first member upon the first gear train being driven; and, a second connector to connect the second member to the second gear train and being controllable to permit movement in the second plane with respect to the second member upon the second gear train being driven.

The first and second gear trains preferably comprise a common geared body having first and second gear segments, the first gear train comprising the first gear segment and a first driving gear arranged to drive the first gear segment and the second gear train comprising the second gear segment and a second driving gear arranged to drive the second gear segment.

The first and second driving gears may each comprise a worm gear.

One or more of the first and second driving gears may be resiliently sprung against the respective first and second gear segment.

One or more of the first and second driving gears may be driven by a motor. The motor may be connected to a controller for automated and/or remote control. For example, the controller may be connected to one or more sensors and arranged to control the motor in dependence on signals received from the one or more sensors. In another example the controller may be connected to a data communications receiver or transceiver and arranged to control the motor in dependence on signals received. Separate motors may drive the first and second driving gears or a common motor may be arranged to drive both gears either serially or in parallel.

The first and second connectors may each comprise mounting plate connected to the driving worm gear and to the common geared body by bolts and nuts, lockable pins or some other connectors. Preferably, bolts and nuts are used that are tightened during installation to apply a compressive force and thereby resist slipping of the respective first or second member about that axis/part. For example, the connector may comprise a nut and bolt arrangement which pass through holes in the mounting plate, through a hole running along the respective axis of the gear, through another hole in the mounting plate before being locked into place with an appropriate nut.

Where the driving gears are motor driven/controlled, it will be appreciated that the bolt and nut would be replaced by (or joined to) a shaft connecting the driving gear to the motor.

An advantage of the positioning assembly of the geared body and two worm gears is that the number of teeth and pitch of the worm gears can be optimised to suit the intended application. In this manner, both gross and fine angular adjustments are achievable within one mechanism. For example, embodiments described below enable an adjustment in horizon and azimuth by increments of approximately 7° and yet can be controlled and operated such that gross adjustments can be achieved very quickly to bring about rough alignment, after which the same mechanism can be used to make fine adjustments to alignment.

In fields such as antenna alignment, such accurate control whilst maintaining ease of operation of the alignment mechanism is extremely useful as the antenna can be quickly brought into rough alignment and then fine-tuned via a single mechanism without needing to use multiple (gross and fine) adjustment mechanisms.

A further advantage of the geared body is that the load is taken through the gear body rather than supporting brackets and the like.

The worm-gear arrangement of embodiments of the present invention is particularly suitable for use with a motor, for example to enable automatic alignment during antenna installation. The worm-gear allows a small motor to be mounted in a convenient location centrally under the gear pin and using a simple drive shaft adapter or collar, for example made of Nylon, to connect the motor drive shaft to the worm gear spindle or pin. The worm gear screw pitch is preferably selected such that a small motor with low torque is sufficient to drive the gear, and consequently this motor can be of small physical size and low power consumption, which is an advantage for easy installation (for example installation on lampposts for millimetre-wave radio links).

The transverse axis arrangement of embodiments of the two worm gears of the present invention has the advantage that adjustment on one axis does not affect the alignment position on the other axis (and vice-versa). This is a particular advantage for aligning millimetre-wave antennas with narrow beamwidths (for example, beamwidths of less than 2 degrees), because it enables the alignment trajectory to sweep in a controlled manner in a straight line along one axis whilst keeping the opposing axis firmly fixed with zero movement along the latter axis. In many existing bracket arrangements, adjusting the alignment on one axis may cause a small shift in alignment on the opposing axis, which results in the alignment trajectory being elliptical instead of a straight-line, and this means that it is very difficult to align the antenna accurately (in fact, it may be almost impossible to align to the peak signal position, because the elliptical trajectory does not allow the peak signal position to be pin-pointed).

The worm gear arrangement of embodiments of the present invention preferably has a single screw adjustment for each individual axis, with said screw adjustment centrally-located on the axis: this has the advantage that the adjustment can be made along each axis without causing any tilting across the opposing axis.

Existing alignment bracket designs use two or more screw adjustment points for each axis, typically one on each side of the device (rather than a single central screw-point), and this means that for each adjustment made, the two screw adjustment points on either side of the device or radio, must be adjusted in exactly equal increments or else the device will suffer tilt along the opposing axis. Tilt across either axis of the alignment bracket is a problem in radio links for the following reason: the radio antenna is required to be mounted in a particular orientation, to ensure that the polarization of the antennas is the same at each end of the link (for example, vertical, horizontal or slant polarized). If one of the antennas suffers tilt across one or both of the axes, then the radio-waves transmitted from that antenna will no longer be polarized in exactly the same direction, and will therefore suffer loss at the receiving antenna which does not have the same tilt angle, and correspondingly the same loss of signal strength will occur for radio-waves travelling in the reverse direction. It is therefore an advantage of the present invention to use a single screw adjustment centrally-located on each axis, in order to avoid any antenna tilt and therefore loss of signal.

Brief Description of the Drawings

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figures la and lb are perspective views of a positioning bracket according to an aspect of the present invention; Figure 2 is an exploded view of the bracket of Figures 1 a and 1 b; Figures 3a and 3b are perspective views of the bracket of Figures 1 a and lb illustrating positioning; and, Figure 4 is a perspective view of a positioning gear according to another aspect of the present invention.

Detailed Description

Figures la and lb are perspective views from opposite directions of a positioning bracket according to an aspect of the present invention. Figure 2 is an exploded view of the bracket of Figures la and lb. Figures 3a and 3b are perspective views of the bracket of Figures la and lb illustrating positioning.

The positioning bracket 20 comprises first and second transversely arranged gear trains 21, 22 which are separately driveable about respective first and second axes 21a, 22a.

The first and second gear trains 21, 22 preferably comprise a common geared body 4 having first and second gear segments 4a, 4b. The first gear train 21 comprises the first gear segment 4a and a first driving gear 5. The first driving gear 5 is arranged to mesh with the first gear segment and drive the first gear segment 4a.

The second gear train 22 comprises the second gear segment 4b and a second driving gear 9. The second driving gear 9 is arranged to mesh with the second gear segment 4b and drive the second gear segment 4b.

A first connector 7 connects a first member (shown here as a wall but could be a mast, equipment etc) lithe first axis 21a.

A second connector 8 connects the second member (shown here also as a wall but could be a mast, equipment etc) 12 to the second axis 22a. In this embodiment, the connectors comprise an assembly of a mounting plate 7a, 8a and bolts/nuts 7b18b, although other arrangements are possible.

In this embodiment, the first and second driving gears 5, 9 are worm gears, although other driving gears could be used. Similarly, although the first and second gear segments are illustrated in the form of arcs having a substantially constant radius, other gear geometries or types could be used.

One or more of the first and second driving gears 5, 9 may be resiliently sprung against the respective first and second gear segment so as to minimise any backlash. In such an arrangement, the spring resilience may be provided at the interface where the warm gear 5, 9 is bolted to the respective mounting plate 7a18a.

It can be seen that the bracket 20 is adjustable for both elevation and azimuth adjustment in this embodiment. The bolts securing the bracket to the respective axis along with the bolt holding the respective driving gear in place control movement in the respective degree of freedom. For example, if one or both of the bolts 7b are locked (or tightened so as to effectively be locked) to prevent the connected parts moving, adjustment of elevation is not possible. Similarly, if one or both of the bolts 8b are locked (or tightened so as to effectively be locked) to prevent the connected pads moving, adjustment of azimuth is not possible.

During installation or adjustment, the pair of bolts 7b or 8b are unlocked/loosened and adjustment in the corresponding degree of freedom is possible. For example, if adjustment is required for elevation then bolts 7b are unlocked/loosened so to allow the first worm gear 5 to drive the first gear segment 4a, as shown in Figure 3a. In a similar manner, bolts 8b can be unlocked/loosened so as to allow azimuth adjustment as shown in Figure 3b.

Adjustment in both orientations can be done simultaneously if desired. The locking of the bolts may be controlled by an electronic or mechanical controller (or indeed may be the bolts some or all of the bolts may be replaced by a drive shaft of a motor such that, for example, the worm gear(s) may be driven by the motor whilst the shafts connecting to the common geared body 4 are allowed to freely rotate and thereby be driven by the worm gear. As the bolt only needs to be loosened/unlocked to allow movement, it may be that a stop or other mechanism may be provided to prevent or resist the nut being completely removed from the thread of the bolt.

The motor may be connected to a controller for automated and/or remote control.

For example, the controller may be connected to one or more sensors and arranged to control the motor in dependence on signals received from the one or more sensors. In another example the controller may be connected to a data communications receiver or transceiver and arranged to control the motor in dependence on signals received. Separate motors may drive the first and second driving gears or a common motor may be arranged to drive both gears either serially or in parallel.

In place of bolts and nuts, a lockable pin or some other connector may be used.

Figure 4 is a perspective view of a positioning gear according to another aspect of the present invention.

The positioning gear 100 comprises a geared body 110 having first 120 and second 130 gear segments mounted respectively about first 120a and second 1 30a axes, the first 1 20a and second axes 1 30a being transverse (and preferably perpendicular although this is not essential) and each of the first and second axes defining a mounting point for mounting the positioning gear (in this embodiment by way of a through hole into which a pin, bolt or drive shaft is inserted so as to be rotated when the geared body rotates about that axis.

As discussed above, gear geometry can be determined subject to application.

Generally, the diameter of the gear segment (4a14b) and that of its respective worm gear together with the number of teeth on the gear segment dictates the ratio of turns. It has been found that using 25 teeth on each gear segment with a tooth pitch of 3 mm is particularly useful and provides the ability for gross adjustment (meaning a limited number of turns is needed by the worm gear) with the ability to finely tune adjustment. In this example, one rotation of the worm gear gives approximately 7° of angular movement.

Claims

Claims 1. A positioning gear comprising a geared body having first and second gear segments mounted respectively about first and second axes, the first and second axes being transverse and each of the first and second axes defining a mounting point for mounting the positioning gear.
2. A positioning gear as claimed in claim 1, wherein the geared body comprises a unitary body.
3. A positioning gear as claimed in claim 1, wherein the geared body comprises an assembly of parts.
4. A positioning gear as claimed in any preceding claim, wherein one or more of the mounting points comprises a shaft for receiving a pin along the respective axis.
5. A positioning gear as claimed in any preceding claim, wherein one or more of the mounting points comprises a post.
6. A positioning gear as claimed in any preceding claim, wherein one or more of the mounting points is at least partly threaded.
7. A positioning gear as claimed in any preceding claim, wherein the geared body is substantially cruciform-shaped.
8. A positioning gear as claimed in any preceding claim, wherein each gear segment is substantially semi-circular.
9. A positioning gear as claimed in any preceding claim, wherein the first and second axes extend in transverse directions and are offset from one another.
10. A positioning bracket, the positioning bracket being adjustably connectable to respective first and second members and comprising: first and second transversely arranged gear trains, the first and second gear trains being separately driveable in respective first and second planes; a first connector to connect the first member to the first gear train and being controllable to permit movement in the first plane with respect to the first member upon the first gear train being driven; and, a second connector to connect the second member to the second gear train and being controllable to permit movement in the second plane with respect to the second member upon the second gear train being driven.
11. A positioning bracket as claimed in claim 10, wherein the first and second gear trains comprise a common geared body having first and second gear segments, the first gear train comprising the first gear segment and a first driving gear arranged to drive the first gear segment and the second gear train comprising the second gear segment and a second driving gear arranged to drive the second gear segment.
12. A positioning bracket as claimed in claim 10, wherein the common geared body comprises the positioning gear of any of claims 1 to 9.
13. A positioning bracket as claimed in claim 10, 11 or 12, wherein one or more of the first and second driving gears comprises a worm gear.
14. A positioning bracket as claimed in claim 10, 11, 12 or 13, wherein one or more of the first and second driving gears is resiliently sprung against the respective first and second gear segment.
15. A positioning bracket as claimed in any of claims 10 to 14, wherein one or more of the first and second connectors comprise a mounting plate connected to the driving worm gear and to the common geared body.
16. A positioning bracket as claimed in claim 15, wherein the mounting plate is connected by bolts and nuts, said nuts and bolts being configured to be tightenable during installation to apply a compressive force and thereby resist slipping of the respective first or second member about that axis/part.
17. A positioning system comprising a positioning bracket as claimed in any of claims 10 to 16 and a motor for driving one or more of the first and second driving gears.
18. A positioning system as claimed in claim 17, further comprising a motor controller configured to control operation of the motor.
19. A positioning system as claimed in claim 18, further comprising a remote control signal receiver, the motor controller being configured to receive remote control signals via the remote control signal receiver and control operation of the motor in dependence on the received signals.
20. A positioning system as claimed in claim 18 or 19, further comprising one or more sensors, the motor controller being configured to receive signals from the one or more sensors and is arranged to control operation of the motor in dependence on signals received from the one or more sensors.
21. A positioning gear as herein described and as illustrated in the accompanying drawing.
22. A positioning bracket as herein described and as illustrated in the accompanying drawings.
23. A positioning system as herein described and as illustrated in the accompanying drawings.