EP1028482A2 - Telescopic mast system - Google Patents

A telescopic mast system, comprising a movable base (1); a telescopic mast (2) comprising an outer mast section (3) and an inner mast section (5) ; a power means (6) for turning the mast; stay ropes (10, 11, 12) for staying the mast so as to render it substantially immovable in the operating position; a stay beam (13, 14) which in the operating position (II) of the mast (2) can be extended laterally from the mast; a diverting element (15, 16) placed at the end of the stay beam; a coiling device (17, 18) for receiving the stay rope passed over the diverting element (15, 16) so as to coil up and tighten the stay rope. The stretcher device (19) comprises a slide (20) movable on and guided by the outer mast section (3); a bearing rod (21) pivotally connected by one end (22) to the slide (20) and by the other end to the base (1) so that the bearing rod (21) turns in a parallel plane with the mast and the power means (6); and a turning rod (25) pivotally connected by one end (26) to the slide (20) and by the other end (27) to the stay beam (13, 14) to turn the stay beam between the position (A) where it lies parallel to the mast and t-he outstretched position (B) as the slide is moved along the outer mast section by the action of the bearing rod when the mast is being turned by the power means between the transport position and the operating position.

• The present invention relates to a telescopic mast system as defined in the preamble of

  claim

  1.

• In prior art, a telescopically extendable and retractable mast is known which is mounted on a cross-country vehicle and designed to lift a device, e.g. a radar antenna, to a height while the vehicle is stationary. The mast consists of elongated mast sections disposed in a telescopic arrangement relative to each other and comprising an outer mast section pivotally connected to the vehicle so that it can turn between a horizontal transport position and a vertical operating position. A hydraulic cylinder is provided between the vehicle and the outermost mast section to turn the mast between the horizontal and vertical positions. The inner mast section is inside the outer mast section. In the operating position, the inner mast section forms the topmost mast section in the mast. The antenna is mounted on the top of the inner mast section. In the upright operating position, the mast has to be stiffened with stay ropes to prevent it from bending and swinging. One end of the stay ropes is attached to the free end of the inner mast section, i.e. to the top of the mast. After the mast has been raised to an upright position, the stay ropes are tightened by means of a diverting element and a tensioning device disposed on supporting legs resting on the ground and functioning as stay beams. The supporting legs must be brought to the position resting on the ground before the stay ropes can be tightened. Systems of this type are presented e.g. in specifications EP 0 296 957 A3, DE 38 39 858 A1 and SE 409 320.

• Mounting the base on the ground and dismounting it is a laborious and time-consuming operation. If a vehicle is used as a base, in some cases it will be sufficiently sturdy without being additionally supported by legs resting on the ground. In military use, the slowness of the preparatory phase before reaching the operating position is particularly problematic because it is of essential importance that the device on the top of the mast, e.g. a radar antenna, should be brought very quickly from the transport position to the operating position and vice versa before being detected by the enemy. Therefore, prior-art systems are not suited for military use. A further problem with prior-art systems is that they use separate power means to bring the supporting legs of the base used as stay beams to their extended position, with the result that the system is complicated and expensive.

• The object of the invention is to eliminate the problems referred to above.

• A specific object of the invention is to disclose a telescopic mast system which can be quickly brought from a transport position to an upright position and stiffened so that it is ready for operation.

• Further object of the invention is to disclose a system which minimizes the need for power means, such as hydraulic cylinders.

• As for the features characteristic of the system of the invention, reference is made to the claims.

• According to the invention, the telescopic mast system comprises a stretcher device for turning the stay beam between a position where the stay beam lies in a direction parallel to the mast and a position where the stay beam is at angle to the mast, said stretcher device comprising a slide movable on and guided by the outer mast section; a bearing rod whose one end is pivotally connected to the slide and the other end is pivotally connected to the base with a third joint disposed at a distance from the first joint so that the bearing rod turns in a plane parallel to the plane of the mast and the power means; and a turning rod whose one end is pivotally connected to the slide while its other end is pivotally connected to the stay beam for turning the stay beam between a position parallel to the mast and an outstretched position as the slide is moving along the outer mast section due to the action of the bearing rod when the mast is being turned by the power means between the transport position and the operating position.

• The invention provides the advantage that the system can be very quickly and easily brought from the transport position into the operating position and similarly from the operating position into the transport position. A further advantage is that the stay beam can be stretched out completely mechanically, controlled by the same power means as is used to turn the telescopic mast and simultaneously with the latter. Moreover, the invention allows the system to be completely automated.

• In an embodiment of the system, the system comprises two stay beams which, in the operating position of the mast, are arranged to extend radially in different directions outward from the mast.

• In an embodiment of the system, the stay beam is pivotally connected to the outer mast section.

• In an embodiment of the system, the mast comprises one or more intermediate mast sections arranged telescopically between the outer mast section and the inner mast section.

• In an embodiment of the system, the movable base is an engine-driven vehicle.

• In an embodiment of the system, the vehicle comprises a first end and a second end; and the first joint is disposed on the top of the vehicle near its first end so that, in the transport position, the mast lies on top of the vehicle, oriented in the longitudinal direction of the vehicle toward its second end.

• In an embodiment of the system, the system comprises a first stay beam and a second stay beam which, in their outstretched operating position, extend sideways from a vertical plane determined by the mast and the longitudinal direction of the vehicle to either side of the said plane at equal angles outside the first end of the vehicle; a first coiling device disposed in the vicinity of the first joint on the vehicle; a first stay rope running from the top of the mast via a diverting element on the first stay beam to the first coiling device; a second coiling device disposed in the vicinity of the first joint on the vehicle; a second stay rope running from the top of the mast via a diverting element on the second stay beam to the second coiling device; and a third stay rope connected between the top of the mast and the vehicle.

• In an embodiment of the system, the third stay rope is fastened to the second end of the vehicle.

• In an embodiment of the system, the system comprises a third coiling device for coiling and tightening the third stay rope.

• In an embodiment of the system, the coiling device comprises a rope reel around which the stay rope can be coiled, a braking device for braking the coiling device, and a motor, such as a hydraulic motor, for rotating the coiling device.

• In the following, the invention will be described in detail by the aid of some of its embodiments with reference to the attached drawing, wherein
• Fig. 1 presents a side view of an embodiment of the telescopic mast system of the invention, with the mast in the transport position,
• Fig. 2 presents a perspective view of the system in Fig. 1 in the operating position,
• Fig. 3 presents the system in Fig. 2 in side view,
• Fig. 4 presents the system in Fig. 2 in rear view, and
• Fig. 5 presents a magnified detail of Fig. 3.

• Fig. 1 shows a

  radar vehicle

  1 provided with a telescopic mast system according to the invention. In the figure, the mast is in its transport position on top of the vehicle. The radar antenna to be mounted on the top of the mast is not depicted in Fig. 1 - 5.

• As can be seen from Fig. 1 - 5, the telescopic mast system comprises a

  movable base

  1, which in this example is an engine-driven

  armored cross-country vehicle

  1 on which the mast system has been mounted. The cross-country vehicle can be driven to a desired place and supported on the ground by means of hydraulic supporting legs disposed in the front and rear parts of the vehicle as shown in Fig. 2 - 4, whereupon the

  telescopic mast

  2 can be raised into its upright operating position as illustrated in Fig. 2 - 4.

• The system comprises an extendable and retractable

  telescopic mast

  2, which in this embodiment is a hydraulic multi-stage cylinder system. The

  mast

  2 consists of elongated

  cylindrical mast sections

  3, 28, 29, 5 arranged telescopically relative to each other. An

  outer mast section

  3, which in the upright position is the bottommost mast section, is pivotally mounted with a

  first joint

  4 on the rear end of the

  vehicle

  1. The

  joint

  4 allows the

  mast

  2 to be turned between a horizontal transport position I as shown in Fig. 1 and an upright operating position II as shown in Fig. 2 - 5. Topmost in the

  mast

  2 is an

  inner mast section

  5. Between the

  bottommost mast section

  3 and the

  topmost mast section

  5 there are additionally two intermediate

  telescopic mast sections

  28 and 29.

• The

  mast

  2 is turned between the transport and operating positions by means of a

  hydraulic cylinder

  6. As is best seen from Fig. 5, the

  first end

  7 of the

  hydraulic cylinder

  6 is pivotally connected to the

  vehicle

  1 with a

  second joint

  8, which is disposed at a distance from the

  first joint

  4. The

  second end

  9 of the

  hydraulic cylinder

  6 is pivotally connected to the

  outer mast section

  3 at a point near the end of the latter.

• As illustrated in Fig. 2 - 5, the

  mast

  2 is held immovable by

  stay ropes

  10, 11, 12, which are fastened by their upper ends to the

  inner mast section

  5. The stay ropes preferably consist of steel wire ropes.

• Two

  stay beams

  13, 14 are pivotally connected to the mast near the lower end of the

  outer mast section

  3 so that they can be turned between position A as shown in Fig. 1, where the

  stay beams

  13 and 14 are oriented in a direction substantially parallel to the

  mast

  2, and position B as shown in Fig. 2 - 5, where they are stretched out radially from the mast in different lateral directions. In the outstretched position B, the angle between the

  stay beams

  13, 14 is about 120°. Each

  stay beam

  14, 14 carries a

  diverting pulley

  15, 15 at its end, around which the stay ropes 10, 11 fastened to the top of the mast are passed. From the

  diverting pulley

  15, 16, the

  stay rope

  10, 11 runs further to a

  coiling device

  17, 18. Each

  coiling device

  17, 18 comprises a

  rope reel

  33 on which the

  stay rope

  10, 11 can be coiled, and a hydraulic motor 35 for rotating the

  rope reel

  33. When the

  mast

  2 is being lowered into the transport position, the stay beam is uncoiled from the rope reel while a brake keeps the stay rope suitably tensioned. When the mast is in the upright position, the

  rope reel

  33 is rotated by the hydraulic motor 35 to tighten the

  stay rope

  10, 11 to a suitable tension.

• The

  stay beams

  13, 14 are turned between position A (Fig. 1) and the outstretched position B (Fig. 2 - 5) by means of a

  mechanical stretcher device

  19 as the

  mast

  2 is being turned between the transport position I and the operating position II by the power means 6. The

  stretcher device

  19 comprises a

  slide sleeve

  20 which is movable on the

  outer mast section

  3 and guided by it. One end of the bearing

  rod

  21 is pivotally connected to the

  slide sleeve

  20 and the other end is pivotally connected to the

  base

  1 via a third joint 24, which is disposed at a distance from the

  first joint

  4. The

  rigid bearing rod

  21 turns in a parallel plane with the

  mast

  2 and the power means 19 and moves the

  slide sleeve

  20 on the

  outer mast section

  3. One end of the turning

  rod

  25 is pivotally connected to the

  slide sleeve

  20 while its

  other end

  27 is pivotally connected to the

  stay beam

  13, 14. As the

  slide sleeve

  20 is moved along the

  outer mast section

  3 by the action of the bearing

  rod

  20, the stay beams 13, 14 are simultaneously turned between the position A where they are parallel to the mast and the outstretched position B when the

  mast

  2 is being turned by the power means 6 between the transport position I and the operating position II.

• As shown in Fig. 2, 3 and 5, the system also comprises a

  third stay rope

  12, which is stretched between the top of the

  mast

  2 and the

  front end

  31 of the

  vehicle

  1. The system may comprise a

  coiling device

  32 for the coiling and tensioning of the

  third stay rope

  12. Regarding its operation and structure, coiling

  device

  32 corresponds to the above-described

  coiling devices

  17, 18.

• Although the invention has been described above by way of example in conjunction with a radar vehicle designed for military use, it is obvious that the invention is also applicable for civilian use. The movable base may be a vehicle or trailer. The mast can be used to support any device that needs to be raised to a substantial height. Such a device may be e.g. a telecommunication antenna, such as the antenna of a base station in a mobile communication network. Thus, the system can be used e.g. as a movable base station in a mobile communication network.

• The invention is not restricted to the examples of its embodiments described above, but many variations are possible within the scope of the inventive idea defined in the claims.

1. Telescopic mast system, comprising

   a movable base (1),

   a telescopic mast (2) consisting of mast sections (3, 28, 29, 5) arranged telescopically relative to each other, comprising an outer mast section (3) pivotally connected to the base (1) via a first joint (4) so that it can be turned between a substantially horizontal transport position (I) and a substantially vertical operating position (II), and an inner mast section (5) placed inside the outer mast section and forming the topmost mast section when in the operating position,

   an extendable/retractable type power means (6) whose first end (7) is pivotally connected to the base (1) via a second joint (8) disposed at a distance from the first joint (4), the second end (9) of said power means being pivotally connected to the outer mast section (3) so that the mast can be turned by means of the power means between the above-mentioned transport position and operating position,

   stay ropes (10, 11, 12) fastened to the inner mast section (5) to stay the mast so as to render it substantially immovable in the operating position,

   a stay beam (13, 14) which is so mounted and turnable with respect to the movable base (1) that, in the operating position (II) of the mast (2), the stay beam can be extended laterally to a distance from the mast,

   a diverting element (15, 16) placed at the end of the stay beam to divert the stay rope,

   a coiling device (17, 18) attached to the base (1) to receive the stay rope passed over the diverting element (15, 16) in order to coil up and tighten the stay rope,

      characterized in that the telescopic mast system comprises a stretcher device (19) for turning the stay beam (13, 14) between a position (A) where it is parallel to the mast and an outstretched position (B) where it is at an angle to the mast, said stretcher device (19) comprising:

   a slide (20) movable on and guided by the outer mast section (3),

   a bearing rod (21) pivotally connected by one end (22) to the slide (20) and by the other end to the base (1) via a third joint (24) disposed at a distance from the first joint (4) so that the bearing rod (21) turns in a parallel plane with the mast and the power means (6), and

   a turning rod (25) pivotally connected by one end (26) to the slide (20) and by the other end (27) to the stay beam (13, 14) to turn the stay beam between the position (A) where it lies parallel to the mast and the outstretched position (B) as the slide is moved along the outer mast section by the action of the bearing rod when the mast is being turned by the power means between the transport position and the operating position.

2. System as defined in claim 1, characterized in that the stay beam (13, 14) is pivotally connected to the outer mast section (3).

3. System as defined in claim 1 or 2, characterized in that the system comprises two stay beams (13, 14) arranged to extend radially in different directions from the mast in the operating position (II) of the mast (2) .

4. System as defined in any one of claims 1 - 3, characterized in that it comprises one or more intermediate mast sections (28, 29) telescopically arranged between the outer mast section (3) and the inner mast section (5).

5. System as defined in any one of claims 1 - 4, characterized in that the movable base (1) is an engine-driven vehicle.

6. System as defined in claim 5, characterized in that the vehicle (1) comprises a first end (30) and a second end (31); and that the first joint (4) is disposed on the top of the vehicle (1) near its first end (30) so that, in the transport position (I), the mast (2) lies upon the vehicle, oriented in the longitudinal direction of the vehicle toward the second end (31).

7. System as defined in claim 6, characterized in that the system comprises

   a first stay beam (13) and a second stay beam (14), which in their outstretched operating position extend sideways from a vertical plane determined by the mast (2) and the longitudinal direction of the vehicle to either side of the said plane at equal angles outside the first end (30) of the vehicle,

   a first coiling device (17) disposed in the vicinity of the first joint (4) on the vehicle (1),

   a first stay rope (10) running from the top of the mast (2) via a first diverting element (15) on the first stay beam (13) to the first coiling device (17),

   a second coiling device (18) disposed in the vicinity of the first joint (4) on the vehicle (1),

   a second stay rope (11) running from the top of the mast (2) via a second diverting element (16) on the second stay beam (14) to the second coiling device (18), and

   a third stay rope (12) connected between the top of the mast and the vehicle (1).

8. System as defined in claim 7, characterized in that the third stay rope (12) is fastened to the second end (31) of the vehicle (1).

9. System as defined in claim 7 or 8, characterized in that the system comprises a third coiling device (32) for the coiling and tensioning of the third stay rope.

10. System as defined in claim 7 or 8, characterized in that the coiling device (17, 18, 32) comprises a rope reel (33) around which the stay rope can be coiled, a braking device for braking the rope reel, and a motor (34), such as a hydraulic motor, for rotating the rope reel.