Transportation system for extensible members

Abstract

 A transportation system for an extensible member (24) such as telescopic mast comprises a wheeled base member (2) carrying a support mechanism including a support member (8) on which the extensible member (24) is mounted and pivotal about a first axis extending transversely of the base member (2) through one end of the support member (8) and fixed relative to the base member (2), an elongate link member (34) one end of which is pivotal about a further axis (32) fixed relative to the base member (2) and parallel with but spaced from the first axis, and drive means (42) reacting between the support member (8) and the link member (34). On actuation of the drive means (42), the support member (8) and the link member (34) are pivotal about their associated axes to move the extensible member (24) between an inoperative position extending substantially longitudinally of the base member (2) and a substantially upright operative position.

Description

[0001] This invention relates to a transportation system for extensible members and has particular, though not exclusive, application to such systems for extensible mast assemblies capable of transportation and erection by a single person.

[0002] A variety of telescopic masts are known for elevating headloads such as aerials, anemometers, surveying equipment, lighting units, cameras and the like, the masts being extensible typically by pneumatic or mechanical means.

[0003] Such masts must be mobile to enable their deployment at desired locations, and there are various known arrangments for achieving this mobility all of which suffer from certain disadvantages.

[0004] Masts have been mounted on a dedicated vehicle, but, with such an arrangement, the cost of the vehicle must be added to that of the mast assembly making the overall cost extremely expensive. Further, the mast availability is directly related to the vehicle serviceability, and the mast can only be deployed in places to which vehicular access is available.

[0005] It is also known to mount telescopic masts on associated trailers which can be towed to the desired locations, the masts then being pivotal on the trailers to upright, operative positions.

[0006] However, such trailers are large and heavy, as their size and weight are related to the extended height of the associated mast, while the overall weight and dimensions of these trailers impose limitations on the use of the masts, restricting deployment of the mast to places with vehicular access and hardstanding.

[0007] It is also known to provide masts without any directly associated transport, such masts being carried to the desired location, erected and maintained in their upright positions by means of guy ropes and the like.

[0008] However, such masts invariably require the presence of at least two people to carry the mast to the desired location and to assist with the erection.

[0009] It would be desirable to be able to provide an extensible mast readily transportable even to relatively inaccessible locations by a single person and capable of erection at that location by a single person.

[0010] According to the present invention, there is provided a transportation system for an extensible member, in particular an extensible mast, the system comprising a wheeled base member, and a support mechanism mounted on said base member and carrying the extensible member, characterised in that the support mechanism comprises an elongate support member one end of which is pivotal about a first axis extending transversely of the base member and fixed relative to the base member, said support member carrying or comprising the extensible member, an elongate link member one end of which is pivotal about a further axis fixed relative to the base member and parallel with but spaced from said first axis, and drive means reacting between the support mnember and the link member in such a manner that, on actuation of the drive means, the support member and the link member are pivotal about their associated axes to move the extensible member between an inoperative position extending substantially longitudinally of the base member and a substantially upright operative position.

[0011] Preferably the drive means comprises a rope winch mounted at or adjacent the free end of the link member, the rope thereof being attached to the support member in such a manner that appropriate manual rotation of the winch effects said pivoting movements of the support member and the link member, during which movements the free end of the link member slides along the support member.

[0012] Conveniently the link member comprises a ladder which, with the extensible member in its substantially upright operative position, provides access to the top of the extensible member prior to extension thereof.

[0013] The transportation system may further include a plurality of telescopic stays one end of each of which is pivotally mounted to an upper region of the support member such that, with the extensible member in its operative position, said stays can be pivoted and extended from stowed positions on the support member to operative positions extending downwardly and outwardly from the support member and in which the other ends thereof engage the ground to provide further support to the extensible member.

[0014] Preferably said other ends of the telescopic stays are interconnected with the support member by associated extensible cords to determine the operative positions of said other ends of the stays.

[0015] Conveniently the base member is provided with a pair of wheels to that side of the further axis remote from the first axis, the track width of said wheels preferably being variable.

[0016] By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which:

Fig. 1 is a side view of a transportation system according to the invention with the extensible mast in its inoperative position on the base member;

Fig. 2 is a side view of the transportation system of Fig. 1 with the mast in an upright operative position, and

Fig. 3 is a rear view of the transportation system of Fig. 2 in the direction of arrow 'A' in Fig. 2.

[0017] Referring to the drawings, the illustrated transportation system comprises a wheeled base member indicated generally at 2 and including a horizontal platform 4 the front of which seats on the ground, and a pair of wheels 6 to the rear of the platform 4 the track width of which can be varied for reasons which will become apparent.

[0018] Pivotally mounted on a horizontal axis extending transversely of the front regions of the platform 4 is one end of an elongate support member in the form of a framework 8 comprising a base portion 10, a pair of parallel side portions 12 and a top portion 14. A bar 16 extends across an intermediate region of the framework 8 for reasons which will become apparent.

[0019] Upper and lower brackets 18,20 secured to the framework 8 locate the lower section 22 of a telescopic mast 24 on the support member whereby the mast 24 extends parallel to, and is movable angularly with, the support member. The mast 24 further includes extensible sections 26,28,30.

[0020] Pivotally mounted on a horizontal axis 32 extending transversely of the rear regions of the platform 4 is one end of a link member in the form of a ladder 34 comprising parallel side portions 36 and a plurality of horizontal rungs 38, the side portions 36 being spaced apart by the same distance as the side portions 12 of the framework 8.

[0021] The upper ends of the side portions 36 of the ladder 34 engage intermediate regions of the side portions 12 of the framework 8, said upper ends of the side portions 36 being guided for sliding movement relative to the framework 8 by a pair of brackets 40 attached thereto and engaging the inside faces of the side portions 12 of the framework 8, guide pins on the brackets 40 co-operating with the side portions 12 of the framework 8 further to maintain said sliding contact between the ladder 34 and the framework 8.

[0022] Mounted between the brackets 40 at the upper end of the ladder 34 is a rope winch 42 comprising a rotatable barrel 44, a handle 46 and a cable 48 wound round the barrel 44. The cable 48 extends from the barrel 44 round a first guide pulley wheel 50 mounted on the top portion 14 of the framework 8, round a second guide pulley wheel 52 mounted on the bar 16 and back to the barrel 44.

[0023] The arrangements is thus such that, with the framework 8 and ladder 34 in their inoperative conditions as shown in Fig. 1, in which the winch 42 is located intermediate the top portion 14 and the bar 16 on the framework 8 and in which the telescopic mast 24 extends substantially longitudinally of the base member 2, rotation of the barrel 44 by means of the handle 46 causes the closed-loop cable 48 to pivot the framework 8 and the ladder 34 in clockwise directions as viewed in Fig. 1 about their respective horizontal axes towards operative positions shown in Figs. 2 and 3 in which the winch 42 is located adjacent the bar 16 on the framework 8 and in which said framework 8 and attached mast 24 are substantially upright and the ladder 34 makes a small angle with the vertical.

[0024] A pneumatic pump 54 and associated power unit 56 are mounted on the platform 4, actuation of which causes extension of the sections 26,28,30 of the mast 24.

[0025] The transportation system further includes a plurality of elongate extensible stays 58, for example four, spaced around the lower section 22 of the mast 24, the upper end of each stay 58 being pivotally mounted to the upper bracket 18 on the framework 8. The stays 58 have an inoperative stored position in which they are releasably secured to the lower section 22 of the mast 24 to extend therealong as shown in Fig. 1.

[0026] When the mast 24 is in its upright position, the stays 58 can be released from the mast, pivoted about their upper ends and extended to adopt operative positions as shown in Figs. 2 and 3 in which the lower ends thereof engage the ground and support the mast 24.

[0027] Conveniently the lower ends of the stays 58 are each interconnected with the lower section 22 of the mast 24 by an associated adjustable cord 60 the position of which can be locked to locate the lower end of the stay 58 in a desired outermost position.

[0028] The above-described transportation system can be towed by a vehicle to a desired destination either by direct attachment to the vehicle, for example by way of the upper regions of the framework 8 and such that the framework 8 and attached mast 24 extend substantially horizontally, or by mounting the system on a trailer itself towed by the vehicle.

[0029] In the first case, the wheels 6 would be moved outwardly to provide maximum track width and therefore maximum stability to the system during towing.

[0030] Once adjacent the desired location, the system can readily be pushed by a single person to the precise location for the mast. More particularly, and referring to Fig. 1, the user would hold the unextended sections of the mast and pivot the system in an anti-clockwise direction to raise the platform 4 from the ground thereby enabling the system to be pushed along on its wheels 6.

[0031] Maximum track width of the wheels 6 would be used when moving over rough terrain, while the track width can be reduced to enable passage of the system through narrow gates or other entrances of restricted width.

[0032] Once at the required location, the system is swivelled about the wheels 6 until the axle of the wheels is exactly horizontal as determined by a spirit level on the platform 4, and the platform is lowered onto the ground.

[0033] The handle 46 is then rotated to raise the framework 8, mast 24 and ladder 34 as detailed above towards the upright position of the mast 24 and until a spirit level on the mast and extending perpendicular to that on the platform is horizontal. The mast is then vertical.

[0034] The telescopic stays 58 are pivoted outwardly and extended into their operative positions shown in Fig. 2 and 3 and the cords 60 are clamped to maintain the operative positions of the stays 58.

[0035] In this operative position of the support mechanism, the ladder 34 is located at a convenient angle for the user to climb the ladder and to locate equipment, such as an aerial, an anemometer, a camera or the like on the top of the unextended mast 24, after which the mast can be extended by appropriate actuation of the power unit 56 and pump 54.

[0036] It will be appreciated that the above-described procedure can readily be carried out by a single person, while dismounting of the mast is achieved by reversing the procedure.

[0037] Furthermore the compact nature of the system and its relatively light weight enable movement to otherwise in­accessible regions, while the variable track width, in particular the facility significantly to increase the spacing between the wheels 6, enables movement in a relatively stable manner over relatively rough terrain.

[0038] As detailed above, the mast 24 can be positioned precisely vertically without the use of jacks or the like and merely by appropriate swivelling of the system on the wheels 6 and pivoting of the mast support mechanism.

[0039] The precise construction of the system may vary from that illustrated without departing from the scope of the invention. Pivoting movement of the support mechanism may be achieved by other than a winch and cable, for example by a rack and pinion, while the base member 2 may further include a pair of small wheels or ptfe slides at the front thereof to facilitate mounting pavements and the like.

[0040] Further, for some less-demanding uses of the system, the telescopic stays 58 may be replaced by fixed-length stays the upper ends of which are attached by articulated joints to extensions of the sliding brackets 40.

[0041] In the travelling position of the system shown in Fig. 1, these stays adopt stored positions substantially as those of the stays 58 and extend almost to the base of the mast 24.

[0042] Prior to erection of the mast, the fixed length stays are moved from their stored positions to positions which allow movement of the sliding brackets 40 along the side portions 12 of the framework 8.

[0043] The winch 42 is then operated until the mast 24 is vertical and the stays are positioned to extend outwardly and downwardly of the mast, the articulated nature of the joints allowing the lower ends of the stays to engage the ground and support the mast 24.

[0044] Again the lower ends of the stays are interconnected with the support member 8 by associated extensible cords.

Claims

1. A transportation system for an extensible member (24) comprising a wheeled base member (2) and a support mechanism (8,34) mounted on the base member (2) and carrying the extensible member (24), characterised in that the support mechanism comprises an elongate support member (8) one end of which is pivotal about a first axis fixed relative to the base member (2), said support member (8) carrying the extensible member (24), an elongate link member (34) one end of which is pivotal about a further axis (32) fixed relative to the base member (2) and parallel with but spaced from said first axis, and drive means (42) reacting between the support member (8) and the link member (34) in such a manner that, on actuation of the drive means (42), the support member (8) and the link member (34) are pivotal about their associated axes to move the extensible member (24) between an inoperative position extending substantially longitudinally of the base member (2) and a substantially upright operative position.

2. A system as claimed in claim 1 in which the drive means comprises a rope winch (42) mounted at or adjacent the free end of the link member (34), the rope (48) thereof being attached to the support member (8) in such a manner that appropriate manual rotation of the winch (42) effects said pivoting movements of the support member (8) and the link member (34), during which movements the free end of the link member (34) slides along the support member (8).

3. A system as claimed in claim 1 or claim 2 in which the link member comprises a ladder (34) which, with the extensible member (24) in its substantially upright operative position, provides access to the top of the extensible member prior to extension thereof.

4. A system as claimed in any one of claims 1 to 3 and including a plurality of telescopic stays (58) one end of each of which is pivotally mounted to an upper region of the support member (8) such that, with the extensible member (24) in its operative position, said stays (58) can be pivoted and extended from stowed positions extending downwardly and outwardly from the support member (8) and in which the other ends thereof engage the ground to provide further support to the extensible member (24).

5. A system as claimed in claim 4 in which the other ends of the telescopic stays (58) are interconnected with the support member (8) by associated extensible cords (60) to determine the operative positions of said other ends of the stays (58).

6. A system as claimed in any one of claims 1 to 5 in which the base member (2) is provided with a pair of wheels (6) to that side of the further axis (32) remote from the first axis, the track width of said wheels (6) being variable.

Drawing