GB2523563A

GB2523563A - A mast and system

Info

Publication number: GB2523563A
Application number: GB1403440.9A
Authority: GB
Inventors: Gordon Humphreys
Original assignee: ABACUS LIGHTING HOLDINGS Ltd
Current assignee: ABACUS LIGHTING HOLDINGS Ltd
Priority date: 2014-02-27
Filing date: 2014-02-27
Publication date: 2015-09-02
Anticipated expiration: 2034-02-27
Also published as: GB2523563B; GB201403440D0

Abstract

A folding lighting mast comprises a base 2, a pivotable mast member 3 and a locking element. A driving mechanism moves the locking element between locked and unlocked conditions, thus securing or releasing the mast to pivot. The pivot axis of the mast may be offset from the locking element. The locking element may comprise one or more pins 51 that co-operate with one or more apertures. The driving mechanism may be pneumatic, hydraulic, mechanical or electromagnetic. An actuator 7 may be used to drive the rotation of the mast. A sensor system may be used to detect whether the locking element is in the locked or unlocked condition, and whether the mast is raised or lowered. The locking element may include a cover to restrict access.

Description

Title: A Mast and System Descriøtion of Invention The present invention relates to a lighting mast of a type which comprises a mast base and a pivotable lighting mast member which is configured for rotation with respect to the mast base. Embodiments may also include a lighting system including a plurality of such lighting masts.

A known lighting mast is disclosed in W02006/059072. This lighting mast disclosed in this document comprises a mast base and a pivotable lighting mast member which is coupled to the mast base. The pivotable lighting mast member can be rotated about a pivot from a raised to a lowered position with respect to the mast base.

The pivotable lighting mast member disclosed in this document is lockable against rotation with respect to the mast base by engagement of a protrusion of the pivotable lighting mast member with a recess of the mast base. Cam plates, moveable by the associated actuators, are configured to engage a first part of respective apertures to hold the protrusion within the recess. When lowering of the mast is required, the cam plates are disengaged from the first part of the respective apertures. The pivotable lighting mast member is then raised with respect to the mast base such that the cam plates align with receptive second parts of the apertures. In such a raised position, the protrusion and recess are disengaged and the pivotable lighting mast member is rotatable about a pivot axis which is aligned with an axis of the cam plates.

This prior art lighting mast is complex and comparatively expensive.

Embodiments of the present invention seek to ameliorate one or more

problems associated with the prior art.

Accordingly, an aspect of the present invention provides a mast, comprising: a mast base; a pivotable mast member, the pivotable mast member being pivotably coupled to the mast base for rotation with respect to the mast base; a driving mechanism; and a locking element having a first locking part and a co- operative locking part, the first locking part being configured to engage the co-operative locking part in a locked condition to inhibit rotation of the pivotable mast member with respect to the mast base, and the first locking part being further configured to disengage the co-operative locking part in an unlocked condition to allow rotation of the pivotable mast member with respect to the mast base, wherein the driving mechanism is configured to drive movement of the first locking part with respect to the pivotable mast member and the mast base, between the locked and unlocked conditions.

The pivotable mast member may be configured for rotation with respect to the mast base about a pivot axis, and the pivot axis may be offset from the locking element.

The first locking part may include one or more pins and the co-operative locking part includes one or more apertures, the one or more pins being configured for receipt by the one or more apertures.

The driving mechanism may be pneumatic or hydraulically driven.

The driving mechanism may be mechanically or electromechanically driven.

The mast may further comprise an actuator which is configured to drive rotation of the pivotable mast member with respect to the mast base.

The mast may further comprise a ram which is configured to inhibit rotation of the pivotable mast member with respect to the mast base.

The mast may further comprise a sensor system configured to sense whether the first locking part is in the locked or unlocked condition.

The sensor system may be further configured to sense whether the pivotable mast member is in a lowered or raised condition.

The locking element may include a cover which is configured to restrict access to the first locking part.

The mast may further comprise a lighting unit.

Another aspect provides a system including a plurality of masts.

Embodiments of the present invention are described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a mast of some embodiments in a raised condition; Figure 2 shows a mast of some embodiments in a lowered condition; Figure 3 shows a lower portion of some embodiments of the mast in the lowered condition; Figure 4 shows a lower portion of some embodiments of the mast in the raised condition; Figure 5 shows a cross-sectional view of a lower portion of a mast of some embodiments in a lowered condition; Figure 6 shows a cross-sectional view of a lower portion of a mast of some embodiments in an unlocked condition; Figure 7 shows a cross-sectional view of a lower portion of a mast of some embodiments in a locked condition; Figure 8 shows a portion of a lower portion of a mast near a lowered condition; Figure 9 shows a portion of a lower portion of a mast near a raised condition; and Figure 10 shows a sensor system of some embodiments.

With reference to, for example, figures 1 to 9, embodiments of the present invention include a lighting mast 1. The lighting mast 1 includes a mast base 2 and a pivotable lighting mast member 3. The pivotable lighting mast member 3 is pivotably coupled to the mast member and is configured for rotation with respect to the mast base 2.

In some embodiments, the lighting mast 1 includes a lighting unit 4. The lighting unit 4 is typically located towards a remote end of the pivotable lighting mast member 3 and is attached thereto. The lighting unit 4 may include one or more lighting elements such as spotlights, floodlights, or the like. The lighting mast 1 may include electrical system for transmitting electrical power from towards the mast base 2 to the lighting unit 4. In some embodiments, the lighting unit 4 includes at least one camera and/or communications antenna (which may be in the form of a parabolic dish, part of a mobile telephone (i.e. cellular phone) base station, an array of antennae, or the like). In such embodiments, the lighting unit 4 may or may not include one or more lighting elements. Accordingly, the mast 1 may not be a lighting mast 1 but could be a communication mast (including at least one antenna) or surveillance mast (including at least one camera). In some embodiments, the lighting unit 4 (with or without any lighting elements) may include a monitoring station (such as a weather monitoring station) with one or more sensors to measure an environmental parameter (e.g. temperature or wind speed) in the proximity of the mast. All of the teachings herein in relation to a lighting mast 1 apply equally to similar masts for other purposes (such as communication or surveillance masts).

The lighting mast 1 includes a locking element 5 having a first locking part 51, such as a pin, and a co-operative locking part 52, such as an aperture of a corresponding size and shape to the first locking part 51 The first locking part 51 is configured to engage the co-operative locking part 52 in a locked condition to inhibit rotation of the pivotable lighting mast member 3 with respect to the mast base 2. The first locking part 51 is further configured to disengage the co-operative locking part 52 in an unlocked condition to allow rotation of the pivotable lighting mast member 3 with respect to the mast base 2.

The lighting mast 1 also includes a driving mechanism 6 which is configured to drive movement of the first locking part 51 with respect to the pivotable lighting mast member 3 and the mast base 2, between the locked and unlocked conditions.

The lighting mast 1 may be moveable between a raised and a lowered condition.

In the raised condition, the pivotable lighting mast member 3 has a longitudinal axis which is generally parallel to a longitudinal axis of the mast base 2 (and may be aligned therewith in some embodiments). In many installations of embodiments of the invention, the lighting mast 1 will extend generally vertically when in the raised condition. As will be appreciated, with the lighting mast 1 in the raised condition, the pivotable lighting mast member 3 is in a raised condition with respect to the mast base 2.

In the lowered condition, the pivotable lighting mast member 3 has a longitudinal axis which is extends approximately perpendicular to the longitudinal axis of the mast base 2. In many installations of embodiments of the invention, the lighting mast 1 will have a mast base 2 which extends generally vertically and a pivotable lighting mast member 3 which extends generally horizontal when in the lowered condition. As will be appreciated, with the lighting mast in the lowered condition, the pivotable lighting mast member 3 is in a lowered condition with respect to the mast base 2. In some embodiments, "perpendicular" is near perpendicular and may be 5-10 degrees from perpendicular (similarly, "horizontal" may be near horizontal and may be 5-30 degrees from horizontal, 5-20 degrees from horizontal, 5-10 degrees from horizontal, 10-30 degrees from horizontal, or 20-30 degrees from horizontal).

In the lowered condition, the lighting mast 1 is such that a lighting unit 4 of the lighting mast 1 is more accessible -for example, to provide access for maintenance or storage. In the raised condition, the lighting mast 1 may have a height of at least 20m (e.g. 22m). In the lowered condition, the lighting unit 4 may be between lm and Sm from a ground surface. In some embodiments, the height of the lighting mast 1 is at least 30m, at least 40m, at least SOm, or at least 60m. In some embodiments, the lighting mast 1 is between Sm and 60m in height.

In some embodiments, the lowered condition is used in order to comply with local operating rules and regulations -for example, the provision of floodlighting using a lighting mast 1 may be permitted only if the lighting mast 1 does not exceed a certain height when not in use or is not visible from a predetermined location when not in use ("in use" in this instance meaning lighting an area of ground such as a football (i.e. soccer) or cricket pitch or other sporting arena for example).

Accordingly, in some embodiments, the mast base 2 may comprise a column 21 which is secured to a base plate 22. The base plate 22 may be configured to be secured to a ground surface which may, in some embodiments, be a lighting mast foundation such as a concrete base. Accordingly, the base plate 22 may define one or more ground securing apertures 23. The ground securing apertures 23 may each be configured to receive, for example, a bolt to secure the mast base 2 to the ground surface.

The base plate 22 may further define a utilities aperture 221 through which, for example, one or more cables (preferably two or more such cables) of the electrical system. In some embodiments, a plurality of utilities apertures 221 is provided. In some embodiments, the or each utilities aperture 221 is generally defined by the base plate 22 such that they provide access, through the base plate 22, to an interior of the column 21.

The column 21 is attached to the base plate 22 -e.g. bolted, welded, etc. The column 21 extends from the base plate 22 in a direction which is generally perpendicular to a main plane of the base plate 22.

The column 21 may have a square or rectangular cross-sectional shape -although could have a circular cross-sectional shape in some embodiments.

The column 21 rises to a first height above the base plate 22.

Towards an end of the column 21 remote from the base plate 22 is a first pivot mount 24 which is configured to couple the pivotable lighting mast member 3 to the mast base 2. The first pivot mount 24 may comprise, for example, a pair of internal pivot plates 241 which are configured to be secured to the mast base 2 (e.g. to the column 21) such that they generally oppose each other across a width of the mast base 2 (e.g. across a width of the column 21).

Each internal pivot plate 241 may define an aperture 242 therethrough and may be configured to carry a bearing 243. The first pivot mount 24 may be configured to carry a pivot pin 244 -e.g. through the respective apertures 242 defined by the internal pivot plates 241 (and preferably bearing on the respective bearings 243).

The pivotable lighting mast member 3 may include a second pivot mount 33 which is configured for cooperation with the first pivot mount 24. Accordingly, the second pivot mount 33 may include, for example, a pair of external pivot plates 331 which are similar to the pair of internal pivot plates 241 and which may be configured to be secured to the pivotable lighting mast 3 such that they generally oppose each other across a width thereof. Each external pivot plate 331 may define an aperture 333 therethrough and may be configured to carry a bearing 332 (which may be bearing 243 in some embodiments which is jointly carried by a respective internal and external pivot plate 241, 331). The second pivot mount 33 may, therefore, also be configured to carry the pivot pin 244 and the apertures 333 defined by the second pivot mount 33 may be generally aligned with the apertures 241 defined by the first pivot mount 24.

The pivot pin 244 may, therefore, be configured to be received (a least partially) by the apertures 333,242 defined by the pivot mounts 33, 24, and may bear against the bearings 243,332.

Other configurations of coupling between the pivotable lighting mast member 3 and mast base 2 are possible in embodiments of the invention. In some embodiments, the pivot pin 244, in fact, comprises two stubs which are each carried by the pivotable lighting mast member 3 and pivotably coupled to respective internal pivot plate 241 of the first pivot mount 24 (or vice versa). In some embodiments, the pivotable lighting mast member 3 is configured for rotation about the pivot pin 244 and the pivot pin 244 may be configured such that it is held against rotation with respect to the mast base 2 by the pivot mount 24. In some embodiments, the pivotable lighting mast member 3 is held against rotation with respect to the pivot pin 244 and the pivot pin 244 is configured for rotation with respect to the mast base 2. In some embodiments, both the mast base 2 and pivotable lighting mast member 3 are substantially tree to rotate with respect to each other and the pivot pin 244.

In any event, the pivotable lighting mast member 3 is coupled to the mast base 2 such that the pivotable lighting mast member 3 may rotate with respect to the mast base 2 about a pivot axis (which may be the longitudinal axis of the pivot pin 244).

The pivotable lighting mast member 3 may be coupled to the mast base 2 such that a distance from a first end 31 of the pivotable lighting mast member 3 to the pivot axis is less than the height of the column 21 of the mast base 2.

A second end 32 of the pivotable lighting mast member 3 is towards the lighting unit 4 (if provided) and the distance from the second end 32 to the pivot axis is generally much greater than the distance of the first end 31 from the pivot axis.

In embodiments, a receiving portion 34 of the pivotable lighting mast member 3 is provided towards the first end 31 of the pivotable lighting mast member 3.

The receiving portion 34 is configured to receive at least part of the mast base 2. The receiving portion 34 may, therefore, have a generally U-shaped cross-sectional shape -such that a portion of the mast base 2 may be received through the open side of the U-shaped receiving portion 34.

In some embodiments, the receiving portion 34 is attached to a body portion of the pivotable lighting mast member 3. The body portion 35 is located towards the second end 32 of the pivotable lighting mast member 3 relative to the pivot axis. The body portion 35 may be such that, when the lighting mast 1 is in the raised configuration, the body portion 35 is positioned above the mast base 2 and sufficiently far from the pivot axis so as not to impede rotation of the pivotable lighting mast member 3 with respect to the mast base 2.

In embodiments, a mast portion 36 of the pivotable lighting mast member 3 is provided towards the second end 32 relative to the body portion 35. The lighting unit 4 may be attached to the mast portion 36 towards the second end 32.

The lighting mast 1 may include a ram or actuator 7 which is configured to drive rotation of the pivotable lighting mast member 3 with respect to the mast base 2. The ram or actuator 7 may, therefore, be coupled to the pivotable lighting mast member 3 and the mast base 2.

In some embodiments, a first end of the ram or actuator 7 is coupled to the pivotable lighting mast member 3 and a second end of the ram or actuator 7 is coupled to the mast base 2. Accordingly, the pivotable lighting mast member 3 may include a first actuator mount 351 and the mast base 2 may include a second actuator mount 222 -each actuator mount 351,222 being configured for attachment to the ram or actuator 7.

The first actuator mount 351 may be attached to or part of the body portion 35.

The second actuator mount 222 may be attached to or part of the base plate 22 or column 21 or both the base plate 22 and the column 21.

In embodiments the actuator mounts 351,222 each comprise a respective tongue defining an aperture which is configured to receive a pin which is also configured to pass through an aperture defined by the ram or actuator 7.

The actuator mounts 351,22 are located on a side of the lighting mast 1 which is towards the lighting unit 4 when the lighting mast 1 is in a lowered configuration.

In some embodiments, the ram or actuator 7 is coupleable to a fluid delivery arrangement to drive movement of a piston of the ram or actuator 7 to drive the ram or actuator 7 between an extended and retracted configuration. The fluid delivery arrangement may be part of the lighting mast 1 or may be independent of the lighting mast 1. In embodiments, the ram or actuator 7 is removable from the rest of the lighting mast 1 such that it can be attached when required and removed when not needed.

In some embodiments, the ram or actuator 7 does not drive movement of the pivotable lighting mast member 3 with respect to the mast base 2. Instead, in such embodiments, the ram or actuator 7 is configured to resist movement of the pivotable lighting mast member 3 with respect to the mast base 2. The resistance may be less than the rotational force about the pivot axis which is a result of the weight of the pivotable lighting mast member 3. Accordingly, in such embodiments, the ram or actuator 7 serves to slow movement of the pivotable lighting mast member 3 with respect to the mast base 2 (i.e. from the raised to the lowered condition, and possibly also from the lowered to the raised condition).

The locking element 5 may be coupled to the mast base 2 or the pivotable lighting mast member 3 or both. In particular, in some embodiments, the first locking part 51 is carried by the mast base 2 and the co-operative locking part 52 is carried by the pivotable lighting mast member 3.

Accordingly, in some embodiments, the first locking part 51 engages the co- operative locking part 52 by extension of the first locking part 51 into the co-operative locking part 52. In such embodiments, the first locking part 51 may comprise one or more pins and the co-operative locking part 52 comprises a corresponding number of respective apertures.

The first locking part 51 is driveable between a locked and an unlocked condition with respect to the co-operative locking part 52. Accordingly, in the locked condition, the or each pin of the first locking part 51 may extend such that they are received by one or more respective apertures of the co-operative locking part 52 such that rotation of the pivotable lighting mast member 3 with respect to the mast base 2 is inhibited or substantially prevented. Similarly, in the unlocked condition, the or each pin of the first locking part 51 may be retracted clear of the one or more respective apertures of the co-operative locking part 52 such that rotation of the pivotable lighting mast member 3 with respect to the mast base 2 is permitted.

The driving mechanism 6 is configured to drive movement of the first locking part 51 between the locked and unlocked conditions with respect to the co-operative locking part 52. Accordingly, in some embodiments, the driving mechanism 6 is a hydraulic or pneumatically driven mechanism which is configured to drive extension and/or retraction of one or more pins of the first locking part 51. In some embodiments, the driving mechanism 6 comprises one or more motors or levers which may be coupled to the first locking part 51 by one or more gears (to provide a mechanical or electromechanical driving mechanism 6) and such a mechanism may include a rack and pinion mechanism.

The first locking part 51 may include a plate 511 through which a pin of the first locking parr 51 is configured 10 extend. The plate 511 may be secured to an outer wall of the mast base 2.

The co-operative locking part 52 may also include a plate 521 which defines an aperture 522 which is shaped and sized to receive a pin of the first locking part 51 when the first locking part 51 is in the locked condition. The plate 521 may be bevelled towards the first locking part 52 such that the aperture 522 has a larger dimension (e.g. diameter) towards the first locking part 52 -to ease alignment issues on movement between the unlocked and locked conditions. Similarly, one or more pins forming the first locking part 52 may include respective bevelled ends (such that the or each pin has a smaller diameter towards an end thereof) -again, to ease alignment issues.

The co-operative locking part 52 may include a cover 523 which is configured to restrict access to at least part of the plate 521 and/or the aperture 522 from the outside of the lighting mast 1. Such access may otherwise allow interference with the first locking part 51. The cover 523 may include a removable access panel.

In embodiments, the first locking part 51 includes a pair of pins which are each configured to extend outwardly into a respective aperture 522 of the co-operative locking part 52. The two pins may extend in opposing directions. As such, in some embodiments, the co-operative locking parts 52 are located on opposing sides of the pivotable lighting mast member 3.

The first locking part 51 and co-operating locking part 52 (i.e. the locking element 5) are located remote (i.e. offset) from the pivot axis. In embodiments, the co-operating locking part 52 is coupled to the receiving portion 34. In embodiments, the co-operating locking part 52 is located towards the first end 31 of the pivotable lighting mast member 3.

In embodiments, the lighting mast 1 includes a sensor system 10. The sensor system 10 may include a first sensor 101 which is associated with the first locking part 51 and/or the co-operating locking part 52. The first sensor 101 is configured to sense whether locking element 5 is in the locked or unlocked condition. In some embodiments, the first sensor 101 comprises a sub-sensor associated with each pin (in embodiments in which the first locking part 51 includes one or more pins). Each sub-sensor may be mounted on the co-operating locking part 52. The first sensor 101 (and any sub-sensors thereof) may comprise a proximity sensor. In some embodiments, the first sensor 101 includes at least one sub-sensor which is configured to sense the pressure of a fluid adjacent the sub-sensor (which may be hydraulic or pneumatic fluid). In some embodiments, the first sensor 101 includes one or more sub-sensors which are proximity sensors (which may be configured to sense when the locking element is in the locked condition) and/or one or more sub-sensors which are pressure sensors (which may be configured to sense when the locking element is in the unlocked condition).

The sensor system 10 may include a second sensor 102 which is configured to sense whether the pivotable lighting mast member 3 is in the lowered condition with respect to the mast base 2 (i.e. whether the lighting mast 1 is in the lowered condition). Accordingly, the second sensor 102 may be mounted on the pivotable lighting mast member 3 or mast base 2, and may be configured to sense the proximity of the other of the pivotable lighting mast member 3 or mast base 2.

The sensor system 10 may include a third sensor 103 which is configured to sense whether the pivotable lighting mast member S is in the raised condition with respect to the mast base 2 (i.e. whether the lighting mast 1 is in the raised condition). Accordingly, the second sensor 102 may be mounted on the pivotable lighting mast member 3 or mast base 2, and may be configured to sense the proximity of the other of the pivotable lighting mast member 3 or mast base 2.

The sensor system 10 may be coupled to the driving mechanism 6 such that the locking element 5 can only be actuated from the unlocked to the locked condition when the sensor system 10 confirms that the lighting mast 1 is in the raised condition.

The sensor system 10 may log movements of the lighting mast 1 between the raised and lowered conditions.

Embodiments of the present invention may include a lighting system which includes a plurality of such lighting masts 1. The lighting system may also include other elements including power supply elements -such as power regulators, cabling, and the like.

In some embodiments, the lighting system includes just one such lighting mast 1 and a control unit 200 which is configured to control actuation of the locking element 5 between the locked and unlocked condition and/or which is configured to control actuation of the lighting mast 1 between the raised and lowered condition. In embodiments the control unit 200 includes a user interface 201 configured to receive one or more operator inputs to control these operations. The user interface 201 may be remote from the lighting mast 1 or may be located adjacent the lighting mast 1. In embodiments, the control unit 200 is coupled to a plurality of lighting masts 1 (the lighting system including that plurality of lighting masts 1) and is configured to control the operations of each lighting mast 1 of the plurality (individually or in groups of one or more lighting masts 1). The user interface 201 may be configured to receive such operator inputs to allow a plurality of lighting masts 1 to be so controlled. In some embodiments, the user interface 201 communicatively coupled to at least another part of the control unit 200 by a wireless or wired communicative coupling. Thus, in some embodiments, the operator may be able to move around a site including a plurality of lighting masts 1 and may be able to control the operations of the lighting masts 1 from a mobile device which includes the user interface 201. The user interface 201 may be user interface program which is at least partially provided on a display screen of a computing device. In some embodiments, the control unit 1 may be programmable with one or more control sequences such that a sequence of operations of the plurality of lighting masts 1 can be controlled (e.g. the lowering of a first lighting mast and then the subsequent lowering of a second lighting mast, etc.). The control unit 200 may be communicatively coupled to the sensor system 10 such that confirmation of the condition of the locking element(s) 5 and lighting mast(s) 1 can be obtained -such confirmation may be used as feedback in a control sequence such that an operation of that sequence by be performed only if a confirmation has been received that a previous operation is complete. The communicative coupling between the control unit 200 and the sensor system 10 may be wireless or wired communicative coupling.

In some embodiments, an operator can therefore control the operation of one or more lighting masts 1 without user intervention at the location of the lighting mast 1 -the operation of the lighting masts 1 being substantially entirely controlled through the control unit 200 and user interface 201.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Claims 1. A mast, comprising: a mast base; a pivotable mast member, the pivotable mast member being pivotably coupled to the mast base for rotation with respect to the mast base; a driving mechanism; and a locking element having a first locking part and a co-operative locking part, the first locking part being configured to engage the co-operative locking part in a locked condition to inhibit rotation of the pivotable mast member with respect to the mast base, and the first locking part being further configured to disengage the co-operative locking part in an unlocked condition to allow rotation of the pivotable mast member with respect to the mast base, wherein the driving mechanism is configured to drive movement of the first locking part with respect to the pivotable mast member and the mast base, between the locked and unlocked conditions.
2. A mast according to claim 1, wherein the pivotable mast member is configured for rotation with respect to the mast base about a pivot axis, and the pivot axis is offset from the locking element.
3. A mast according to claim 1 or 2, wherein the first locking part includes one or more pins and the co-operative locking part includes one or more apertures, the one or more pins being configured for receipt by the one or more apertures.
4. A mast according to any preceding claim, wherein the driving mechanism is pneumatic or hydraulically driven.
5. A mast according to any of claims 1 to 3, wherein the driving mechanism is mechanically or electromechanically driven.
6. A mast according to any preceding claim, further comprising an actuator which is configured to drive rotation of the pivotable mast member with respect to the mast base.
7. A mast according to any of claim 1 to 5, further comprising a ram which is configured to inhibit rotation of the pivotable mast member with respect to the mast base.
8. A mast according to any preceding claim, further comprising a sensor system configured to sense whether the first locking part is in the locked or unlocked condition.
9. A mast according to claim 8, wherein the sensor system is further configured to sense whether the pivotable mast member is in a lowered or raised condition.
10. A mast according to any preceding claim, wherein the locking element includes a cover which is configured to restrict access to the first locking part.
11. A mast according to any preceding claim, further comprising a lighting unit.
12. A system including a plurality of masts according to any preceding claim.
13. A mast substantially as herein described with reference to the accompanying drawings.
14. A system substantially as herein described with reference to the accompanying drawings.
15. Any novel feature or novel combination of features disclosed herein.