JP2000296997A - Telescopic mast - Google Patents

Abstract

(57) [Problem] To improve the strength of a mast member in a telescopic mast provided with a fall prevention device when a wire rope for expanding and contracting a plurality of mast members is cut. A fall prevention device can be incorporated into each of the upper and lower mast member pairs. SOLUTION: In a lower part of an upper mast member 12,
The pulley 24 on which the wire rope 36 is hung is supported so as to be vertically movable within a predetermined range. A stopper 57 is swingably supported on the outer surface of the mast member 12, and a support shaft 54 integrated with the pulley 24 is applied to one end of the stopper 57 from below. The other end of the stopper 57 is urged upward by a spring 62. On the inner surface of the lower mast member 11, a protrusion-shaped stopper receiving portion 63 is provided vertically.
When a force is applied from the wire rope 36, the stopper 57 is in a state shown by a solid line in the drawing. When the wire rope 36 breaks, the stopper 57 swings in the state of the chain line, and comes into contact with the stopper receiving portion 63.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic mast, and is used, for example, in a floodlight.

[0002]

Conventionally, for example, Japanese Unexamined Patent Publication No.
As described in Japanese Patent Application Publication No. 1-3614, in a floodlight used for nighttime illumination at a civil engineering work site or the like, an upper end of a telescopic mast that expands and contracts vertically so that the height of the lamp can be adjusted. A lamp is provided. The stretchable mast includes a plurality of, for example, four cylindrical mast members that become gradually thinner, and sequentially inserts a thin mast member serving as an upper mast member inside a thick mast member serving as a lower mast member. The plurality of mast members are configured to be vertically expandable and contractible. In addition, pulleys are respectively provided on the upper and lower portions of the upper and lower two mast members fixed to the chassis, and a wire rope fixed to the lower portion of the uppermost mast member is passed over the pulley. At the same time, the other end of the wire rope is connected to the winch, the wire rope is wound around the winch to extend the telescopic mast from a reduced state, and the wire rope is extended from the winch to reduce the telescopic mast from the expanded state. .

[0003] With this type of telescopic mast, if the wire rope is broken for any reason, the mast member will fall rapidly due to gravity. In particular, the telescopic mast of the floodlight should extend as high as possible to widen the floodlight range when floodlighting, and also hit the ceiling or beams at the time of storage / storage, and increase the stability when moving so that it does not fall. Since the total height at the time of reduction is required to be low, the fall distance at the time of a fall becomes long, and the impact becomes large. Therefore, Japanese Patent Application Laid-Open Nos. Hei 9-213126 and Hei 11-36
As described in Japanese Patent Publication No. 14 or Japanese Patent No. 2773852, various types of fall prevention devices have been conventionally proposed and used.

The above-mentioned JP-A-9-213126, JP-A-11-3614 or Japanese Patent No. 2773852.
The fall prevention device described in the above publication basically supports a part of the pulley movably in a vertical direction or the like, and interlocks a stopper biased by a spring with the pulley, and is supported movably. A stopper receiving portion formed of a through hole is formed on the peripheral wall of the upper or lower mast member provided with the pulley and the stopper. The movable pulley is normally positioned at one end of the movable range by the force applied from the wire rope. In this state, the stopper does not interfere with the stopper receiving portion as the telescopic mast expands and contracts. On the other hand, when the wire rope breaks, since the force acting on the pulley from the wire rope disappears, the movable pulley moves to the other end of the movable range by the bias of the spring, and the stopper operates, By engaging the stopper with the stopper receiving portion, the upper mast member is prevented from falling from the lower mast member.

In the fall prevention devices described in JP-A-9-213126 and JP-A-11-3614, a stopper is provided outside a mast member, and the fall prevention device described in Japanese Patent No. 2773852 is disclosed. Then, the stopper is provided inside the mast member. In the fall prevention device in which the stopper is provided outside the mast member, the stopper is engaged with the stopper receiving portion of the upper mast member of the mast member, and in the fall prevention device in which the stopper is provided inside the mast member, The stopper is engaged with the stopper receiving portion of the lower mast member of the mast member.

Therefore, it is necessary to form a through hole for passing the stopper in the peripheral wall of the mast member provided with the stopper. Further, since the stopper receiving portion is formed by a through hole such as a slit in the peripheral wall of the mast member, the strength of the mast member is reduced.

The present invention is intended to solve such a problem, and the upper mast member falls on the lower mast member when the wire rope is cut without impairing the strength of the mast member. It is an object of the present invention to provide a telescopic mast capable of reliably preventing such a problem.

[0008]

According to a first aspect of the present invention, in order to achieve the above object, a thick mast member which is provided with a plurality of cylindrical mast members which gradually become thinner and which serves as a lower mast member is provided. A thin mast member serving as an upper mast member is sequentially inserted inside to form a plurality of mast members so as to be vertically expandable and contractable, and a wire rope guide provided at an upper part and / or a lower part of these mast members and While being hung over these wire rope guides, one end is fixed to the wire rope fixing portion of the top mast member,
The other end is formed of a wire rope connected to a winch via a wire rope guide on the upper part of the lowermost mast member, and a telescopic mechanism for expanding and contracting the plurality of mast members as a whole, and an upper stage when the wire rope is cut A fall prevention device for preventing the mast member from falling on the lower mast member, wherein the fall prevention device includes a wire rope guide or a wire rope fixing portion with respect to the mast member. A movement-permitting supporting means for supporting a predetermined range of movement, and a locking body supported by a mast member provided with the movement-permitting support means and interlocked with the movement of the movable wire rope guide or wire rope fixing portion. Forward in a direction opposite to the direction of the force applied by the wire rope to the locking body via the wire rope guide or the wire rope fixing portion. An urging means for urging the locking body and an inner surface of a lower mast member provided with the movement-permitting supporting means are provided on the inner surface side of the mast member, and the locking body is moved by the urging of the urging means. In the state, the locking body and a locking body receiving portion whose projection shape on a horizontal plane overlaps with each other.

When the wire rope is wound around the winch from the state where the telescopic mast is reduced, the mast members other than the lowermost one are sequentially raised, and the telescopic mast is extended. Conversely, when the wire rope is fed out of the winch from the state where the telescopic mast is extended, each mast member is sequentially lowered by gravity, and the telescopic mast is reduced. Normally, in the fall prevention device, the wire rope guide or the wire rope fixing portion supported by the movement permitting support means is located at one end of the movable range by the force applied from the wire rope. In this state, the locking body is located on one side of the movable range of the locking body against the urging of the urging means in conjunction with the wire rope guide or the wire rope fixing portion. The locking body receiving portion of the lower mast member and the locking body of the provided mast member do not overlap in the projected shape on the horizontal plane. On the other hand, if the wire rope breaks in the state where the telescopic mast is extended, the mast member starts to fall freely. Further, in the fall prevention device, since the force exerted on the wire rope guide or the wire rope fixing portion by the wire rope is eliminated, the locking body is moved by the urging of the urging means so that the range of movement of the locking body is reduced. , And the projections of the locking members of the upper mast member and the locking member receiving portions of the lower mast member onto the horizontal plane overlap. Therefore, as the upper mast member falls, the locking member of the upper mast member engages with the locking member receiving portion of the lower mast member, and at this time, the upper mast member stops.

The lower mast member having the locking member receiving portion is located outside the upper mast member having the locking member, whereas the locking member receiving portion is provided on the inner surface of the lower mast member. Since it is provided on the side, it is not necessary to form a hole for passing the locking body in the peripheral wall of the mast member, and a fall prevention device is provided for each pair of the upper mast member and the lower mast member It becomes possible.

According to a second aspect of the present invention, in order to achieve the above-mentioned object, there is provided a plurality of cylindrical mast members which gradually become thinner, and an upper mast member is provided inside a thick mast member serving as a lower mast member. A thin mast member is sequentially inserted to form a plurality of mast members so as to be vertically expandable and contractible, and wire rope guides provided on the upper and / or lower portions of these mast members and the wire rope guides A plurality of wire ropes each of which has one end fixed to a wire rope fixing portion of an uppermost mast member and the other end connected to a winch via a wire rope guide on an upper portion of the lowermost mast member. A telescopic mechanism that expands and contracts the entire mast member, and that the upper mast member falls on the lower mast member when the wire rope is cut. In telescoping mast with a fall-prevention device for preventing the fall prevention device includes a movement permitting support means for a predetermined range movably supporting the wire rope guide body or wire rope fixing part relative to said mast member,
The movable wire rope guide or the wire rope fixing portion is supported by a mast member provided with the movement allowing support means, and is interlocked with the movement of the movable wire rope guide or the wire rope fixing portion. Urging means for urging the locking body in a direction opposite to the direction of the force applied by the wire rope to the locking body, and an outer surface of an upper mast member provided with the movable permissible support means. And a locking body receiving portion which is provided on the side and overlaps the locking body and a projected shape on a horizontal plane in a state where the locking body has been moved by the biasing means.

When the wire rope is wound around the winch from the state where the telescopic mast is contracted, the mast members other than the lowermost stage are sequentially raised, and the telescopic mast is extended. Conversely, when the wire rope is fed out of the winch from the state where the telescopic mast is extended, each mast member is sequentially lowered by gravity, and the telescopic mast is reduced. Normally, in the fall prevention device, the wire rope guide or the wire rope fixing portion supported by the movement permitting support means is located at one end of the movable range by the force applied from the wire rope. In this state, the locking body is located on one side of the movable range of the locking body against the urging of the urging means in conjunction with the wire rope guide or the wire rope fixing portion. The locking body receiving portion of the upper mast member and the locking body of the provided mast member do not overlap in the projected shape on the horizontal plane. On the other hand, if the wire rope breaks in the state where the telescopic mast is extended, the mast member starts to fall freely. Further, in the fall prevention device, since the force exerted on the wire rope guide or the wire rope fixing portion by the wire rope is eliminated, the locking body is moved by the urging of the urging means so that the range of movement of the locking body is reduced. And the projections of the locking body receiving portion of the upper mast member and the locking body of the lower mast member onto the horizontal plane overlap. Therefore, as the upper mast member falls, the locking body receiving portion of the upper mast member engages with the locking body of the lower mast member, and at this time, the upper mast member stops.

The lower mast member having the locking member is located outside the upper mast member having the locking member receiving portion, whereas the locking member receiving portion is provided on the outer surface of the upper mast member. Since it is provided on the side, it is not necessary to form a hole for passing the locking body in the peripheral wall of the mast member, and a fall prevention device is provided for each pair of the upper mast member and the lower mast member It becomes possible.

That is, a third aspect of the present invention is the telescopic mast according to the first or second aspect of the present invention, wherein the fall prevention devices are respectively provided on all pairs of the upper mast member and the lower mast member.

According to a fourth aspect of the present invention, in the telescopic mast according to any one of the first to third aspects, the locking member, the urging means, and the locking member receiving portion are provided on the upper mast member and the lower mast member. Two sets are provided, and the positions of the locking member receiving portions in the vertical direction are shifted from each other in both sets.

Thus, when the wire rope is cut and the mast member falls on the lower mast member, any one of the locking members and the urging means may be used depending on the position of the upper mast member at the start of the fall. In the set of the locking body receiving portion, the locking body engages with the locking body receiving portion, and the upper mast member stops. Further, even if one of the two sets of the locking body, the urging means, and the locking body receiving portion is defective, the other set can prevent the upper mast member from falling when the wire rope is cut.

According to a fifth aspect of the present invention, in the telescopic mast according to any one of the first to fourth aspects, the movable permissible support means extends in the up-down direction and can move the wire rope guide or the wire rope fixing portion up and down. The locking body comprises a lever swingably supported by a horizontal support shaft, and is integrally provided with the wire rope guide or the wire rope fixing portion. And a biasing means provided on a mast member having the other end of the lever with respect to the support shaft and the bracket. It consists of a spring mounted between the parts.

Normally, the wire rope guide or the wire rope fixing portion is located at one end of the long hole of the bracket due to the force applied from the wire rope. In this state, the projection of the wire rope guide or the wire rope fixing portion is moved by the lever. By pressing one end of the lever, this lever is in a state of swinging to one side against the force of the spring, and the projected shape on the horizontal plane does not overlap with the locking member receiving portion. On the other hand, when the wire rope breaks, there is no longer any force applied to the lever from the wire rope via the wire rope guide or the wire rope fixing portion. The part is swung while being moved to the other end side of the long hole of the bracket, and the lever and the locking body receiving part are in a state where their projected shapes on the horizontal plane overlap.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a telescopic mast according to the present invention will be described below with reference to FIGS.
The telescopic mast 1 is used for a floodlight used for nighttime lighting or the like at a civil engineering work site, as shown in FIG. 5, for example. In FIG. 5, reference numeral 2 denotes a cart, and the cart 2 has a plurality of wheels 3
have. In addition, the dolly 2 is equipped with a generator 5 which is a power supply of the lighting device 4 and a telescopic mast 1.
The lighting device 4 is provided at the upper end of the telescopic mast 1. This lighting device 4 has a plurality of rotatable lamps 6.

Next, the structure of the telescopic mast 1 will be described.
The telescoping mast 1 is made up of five rectangular cylindrical first mast members 11, second mast members 12, and third mast members 1 that gradually become thinner.
3, the fourth mast member 14 and the fifth mast member 15 are slidably combined with each other.
Thin mast members 12, 13, 14, 15 inside 1, 12, 13, 14
Are sequentially inserted so as to be able to expand and contract vertically. Among them, the first mast member 11, which is the lowermost mast member, is fixed to the carriage 2, and the lighting device 4 is attached to the upper end of the fifth mast member 15, which is the uppermost mast member. , 13,14,15 form the upper mast member. The telescopic mast 1 includes a plurality of pulleys 21, 22, 23, 24, 25, 26, 27,
28, 29, 30, 31, 32, 33, 34, 35, a wire rope 36, and an electric winch 37 are driven by a telescopic mechanism 38 to expand and contract. Although not shown,
The rising limit of the inner mast members 12, 13, 14, 15 with respect to the mast members 11, 12, 13, 14 is as follows.
It is defined by a stopper (not shown) provided below the mast members 12, 13, 14, and 15 coming into contact with a stopper receiver (not shown) provided above the upper part of the mast member 12, from below.

As shown in FIG. 6, the pulleys 21,.
Two (pulleys 21 and 23), a second mast member 12, a third mast member 13 and a fourth mast member 14 are provided above the first mast member 11.
Two at the top and bottom of the car (pulleys 22, 24, ..., 33, 3
5) One (pulley 34) is provided below the fifth mast member 15. Each of the pulleys 21,..., 35 has a horizontal rotation axis.

One pulley 21 on the upper part of the first mast member 11
One part is located inside the first mast member 31 through a through hole formed in the peripheral wall of the first mast member 31, and the other part is located outside. In addition, the other pulley 23 above the first mast member 11 and the pulley 2 above the other mast members 12, 13, 14
3, 25, 27, 29, 31, 33, 35 are mast members 11, 12, 1
Located inside 3,14. Also, the axial direction of the pulleys 23,..., 35 corresponds to the mast member on which the pulleys 23,.
It is perpendicular to the sides of 11, 12, 13, and 14.

The pulleys 22, 24, 26, 28, 30, 32, 34 below the mast members 12, 13, 14, 15 are connected to the mast members 12, 1
It is supported by a bracket 42 fixed on a bottom plate 41 fixed to lower ends of 3, 14, and 15. One of the pulleys 22, 26, 30 below the middle mast members 12, 13, 14 and the pulley 34 below the fifth mast member 15 are connected to the pulleys 22, 2, 14.
It is located outside the mast member 12, 13, 14, 15 provided with 6, 30, 34, and the pulleys 22, 26, 30,
It is perpendicular to the side surfaces of the mast members 12, 13, 14, 15 provided with 34. On the other hand, the other pulleys 24, 28, 32 below the mast members 12, 13, 14 are inclined in the axial direction with respect to the side surfaces of the mast members 12, 13, 14 provided with the pulleys 24, 28, 32. Through a notch-shaped through hole 43 formed in the lower part of the peripheral wall of the mast members 12, 13, and 14 forming the side surfaces, half of the mast members are positioned in the mast members 12, 13, and Half are located outside the mast members 12,13,14. These pulleys 2
4, 28 and 32 are the same mast members 12, 13, 14 as described later.
A wire rope 36 is laid between the upper pulleys 25, 29, and 33 in the inside.

The wire rope 36 is connected to a wire rope fixing member 45 as a wire rope fixing portion provided on a bracket 44 fixed to the lower surface of the bottom plate 41 of the fifth mast member 15.
One end of the pulley 35 is fixed to the other end of the fourth mast member 14, one of the pulleys 35, the lower pulley 34 of the fifth mast member 15, the other pulley 33 of the upper part of the fourth mast member 14, and the fourth mast member.
14, one pulley 32 at the lower part of the third mast member 13, one pulley 31 at the upper part of the third mast member 13, the other pulley 30 at the lower part of the fourth mast member 14,
The other pulley 29 above the third mast member 13, one pulley 28 below the third mast member 13, one pulley 27 above the second mast member 12, and the other pulley below the third mast member 13 Two
6, the other pulley 25 at the top of the second mast member 12, one pulley 24 at the bottom of the second mast member 12, one pulley 23 at the top of the first mast member 11, and the other at the bottom of the second mast member 12. And the other pulley 21 on the top of the first mast member 11 in this order. The wire rope 36 is connected to the mast member 11,
It is located inside 12, 13, and 14, but is led out to the outside at the pulley 21, and the other end is connected to the electric winch 37.

Further, according to the present invention, when the wire rope 36 is cut, the upper mast members 12, 13, 14, 15 are prevented from dropping on the lower mast members 11, 12, 13, 14, respectively. Prevention devices 51 and 52 are provided. Next, the configuration of the fall prevention devices 51 and 52 will be described. This fall prevention device 51,
52 is provided on all of the pairs of the upper mast members 12, 13, 14, 15 and the lower mast members 11, 12, 13, 14, respectively, but the fourth mast member 14, the fifth mast member 15, The fall prevention devices 51 other than the fall prevention device 52 provided therebetween have the same configuration. First, the fall prevention device 51 will be described with reference to FIGS. 1 and 2 by taking an example between the first mast member 11 and the second mast member 12 as an example.

One pulley at the lower part of the second mast member 12
An upward force is applied to the pulley 24 from a wire rope 36 hung on the pulley 24, and the pulley 24 is vertically movable within a predetermined range on a bracket 42 as a movement-permissible supporting means fixed to the second mast member 12. Supported. For this purpose, bearing holes 53 are formed on both side walls of the bracket 42 in the vertical direction, that is, elongated holes extending in the direction of expansion and contraction of the telescopic mast 1. These bearing holes 53 are provided integrally on both sides of the pulley 24. The support shaft 54 is rotatably and vertically slidably supported. A horizontal support shaft fixed to the peripheral wall of the second mast member 12 is located near the pulley 24 and outside the peripheral wall of the second mast member 12.
A lever-shaped stopper 57 serving as a locking body is supported by 56 so as to be swingable within a predetermined range. This stopper 57 is
One end side from 56 is a transmission receiving portion 58, and the other end side is a locking portion 59. One end of the support shaft 54 as a projection is in contact with the transmission receiving portion 58 from below, whereby power is transmitted from the wire rope 36 to the stopper 57 via the pulley 24, Is adapted to receive an upward force on the transmission receiving portion 58 side. Further, a spring 62 as urging means is provided between the locking portion 59 of the stopper 57 and a spring receiving portion 61 provided above the stopper 57 and provided on the outer peripheral surface of the second mast member 12. It is installed. The spring 62 applies an upward force to the stopper 57 side of the stopper 57. Therefore,
Stopper 57 has a force from wire rope 36 and spring 62
However, the force from the wire rope 36 exceeds the force from the spring 62, and the stopper 57 is in a state where the transmission receiving portion 58 side is raised.

On the other hand, at the corner of the inner surface of the peripheral wall of the first mast member 11, which is a mast member adjacent to the second mast member 12, a stopper as a locking body receiving portion comprising projections arranged at predetermined intervals in the vertical direction. A receiving portion 63 is formed. FIG. 4 is an enlarged detailed view of the stopper receiving portion 63, and the mast members 11, 12, 13, and
Screw holes are formed at predetermined intervals in the side wall of 14 and bolts are screwed into these screw holes, and one end of the bolt protrudes in the inner circumferential direction of the mast members 11, 12, 13, and 14. By doing so, the stopper receiving portion 63 is formed. Then, in a state where the transmission receiving portion 58 side of the stopper 57 is raised, that is, in a normal state, the projected shape of the stopper 57 and the stopper receiving portion 63 on the horizontal plane does not overlap, while a state where the locking portion 59 side of the stopper 57 is raised, When the stopper 57 is moved by the bias of the spring 62, the projections of the locking portion 59 of the stopper 57 and the stopper receiving portion 63 on the horizontal plane overlap. The bottom plate 41 of the second mast member 12 has an outer peripheral surface located close to the inner peripheral surface of the first mast member 11,
A notch 64 is formed at a corner of the bottom plate 41 so as not to interfere with the stopper receiving portion 61 of the first mast member 11.

As is clear from the above description, the stopper 57, the spring 62, and the stopper receiving portion 63 of the fall prevention device 51 are located in the gap between the peripheral walls of the first mast member 11 and the second mast member 12. . Further, even when the second mast member 12 is raised to the upper limit position, the pulley 24, the stopper 57 and the spring 62 are located in the first mast member 11.

In the fall prevention device 51 between the second mast member 12 and the third mast member 13, the pulley for transmitting the force exerted by the wire rope 36 to the stopper 57 is the pulley 28, and the third mast member 13 and In the fall prevention device 51 between the fourth mast members 14, the pulley that transmits the force exerted by the wire rope 36 to the stopper 57 is the pulley 32.

Next, the structure of the fall prevention device 52 provided between the fourth mast member 14 and the fifth mast member 15 will be described with reference to FIG. The wire rope 36 fixed to the wire rope fixing tool 45 exerts an upward force on the wire rope fixing tool 45 of the fifth mast member 15, but the wire rope fixing tool 45 is attached to the bottom plate of the fifth mast member 15. Bracket as movable permissible support means fixed by projecting downward to 41
A predetermined range is supported by 44 so that it can move up and down freely. For this purpose, a long hole 66 extending in the vertical direction is formed in the bracket 44, and the wire rope fixing device 45 is supported in the long hole 66 so as to be slidable in the vertical direction. A horizontal fixing pin 67 as a projection for fixing the wire rope 36 is formed on the side surface of the wire rope fixing tool 45 so as to protrude.

The configurations of the stopper 57, the spring 62 and the stopper receiving portion 63 are the same as those of the fall prevention device 51 between the first mast member 11 and the second mast member 12, and accordingly, corresponding portions are denoted by the same reference numerals. The description is omitted here. However, the stopper 57 is a bottom plate of the fifth mast member 15.
A support shaft 56 is attached to a bracket 68 which is fixed by projecting downward to 41.
It is swingably supported by. Further, the fixing pin 67 as a projecting transmission means is in contact with the transmission receiving portion 58 of the stopper 57 from below, whereby the force exerted by the wire rope 36 is applied via the wire rope fixing tool 45. The transmission is transmitted to the stopper 57, and the stopper 57 receives an upward force on the transmission receiving portion 58 side.

As is clear from the above description, the stopper 57, the spring 62 and the stopper receiving portion 63 of the fall prevention device 52 are formed by the bottom plate 41 and the peripheral wall of the fifth mast member 15 and the bottom plate 41 and the peripheral wall of the fourth mast member 14. Is located in the gap between.

Next, the operation of the above configuration will be described. As shown by the chain line in FIG. 5, when the wire rope 36 is wound around the winch 37 from the state where the telescopic mast 21 is contracted, that is, when the wire rope 36 is drawn out of the telescopic mast 1, the innermost fifth The mast member 15 rises,
Then, the fourth mast member 14, the third mast member 13, and the second
The mast member 12 is sequentially raised, and the telescopic mast 1 is extended as shown by a solid line in FIG. Conversely, when the wire rope 36 is extended from the winch 37 from the state where the telescopic mast 1 is extended, that is, when the wire rope 36 is returned into the telescopic mast 1, the second mast member 12, the third mast member
13 and the fourth mast member 14 descend sequentially, and finally the innermost fifth mast member 15 descends, and the telescopic mast 1 contracts.

Normally, in the fall prevention devices 51 and 52, the pulleys 24, 28 and 32 supported by the brackets 42 and 44 via the elongated bearing holes 53 or the wire ropes supported by the elongated holes 66 The fixing tool 45 is located at the upper end side of the movable range defined by the bearing hole 53 or the long hole 66 by the force acting from the wire rope 36 hung or fixed on the pulleys 24, 28, 32. . In this state, pulley 2
When a force is applied to the stopper 57 from the wire rope 36 via the support shaft 54 of 4, 28, 32 or the fixing pin 67 of the wire rope fixing device 45, the stopper 57 is moved as shown by a solid line in FIG. 1 or FIG. Thus, the transmission receiving portion 58 is raised against the force of the spring 62. In this state, the stopper 57 and the mast member 1 having the stopper 57 are provided.
The projection shape on the horizontal plane does not overlap with the stopper receiving portions 63 of the mast members 11, 12, 13, and 14 at the lower stages of 2, 13, 14, and 15. Therefore, the mast members 12, 13, 14, 15 can be moved up and down without the stopper 57 and the stopper receiving portion 63 interfering with each other.

If the wire rope 36 breaks in the state where the telescopic mast 11 is extended, the mast members 12, 13, 14, 15 start to fall freely. When the wire rope 36 is cut, the wire rope 36 is pulled by the pulleys 24,
Since the force acting on the wires 28 and 32 and the wire rope fixing tool 45 is eliminated, the stopper 57 causes the stopper 57 to pivot around the support shaft 56 by the force of the spring 62 as shown by a chain line in FIG. The side swings in the upward direction. In conjunction with this, the pulleys 24, 28, 32 and the wire rope fixture 45 are pushed down by the transmission receiving portion 58 of the stopper 57.
Moves down to the lower end of the movable range with respect to the brackets 42 and 44. In this state, the locking portion 59 of the stopper 57 and the stopper receiving portion 63 of the lower mast members 11, 12, 13, and 14 provided with the stopper 57 are positioned on a horizontal plane. Are overlapped.

Accordingly, as the mast members 12, 13, 14, 15 drop, the locking portions 59 come into contact with the stopper receiving portions 63 from above, and at that time, the mast members 12, 13, 14, 15 stop.
The falling distance of the mast members 12, 13, 14, 15 is determined by the distance between the locking portion 59 at the time when the mast members 12, 13, 14, 15 start to fall and the stopper receiving portion 63 adjacent below the locking portion 59. Only distance.

As described above, according to the configuration of the above embodiment,
When the wire rope 36 breaks, the lower mast member 11, 1
The fall of the upper mast members 12, 13, 14, 15 with respect to 2, 13, 14 can be reliably prevented, and safety is improved. In particular, when this embodiment is used for a floodlight, since the illuminating device 4 is provided at the uppermost end of the mast member 15, parts made of glass or the like of the illuminating device 4 are not damaged by an impact due to a drop.

The lower mast members 11, 12, 13, 14 having the stoppers 57 of the fall prevention devices 51, 52 are connected to the stopper receiving portions.
Since the stopper receiving portion 63 is provided on the inner surface side of the lower mast members 11, 12, 13, and 14, while the mast members 12, 13, 14, and 15 having the 63 are located outside the upper mast members 12, 13, 14, and 15. Stopper 57
Mast members 11, such as slits for passing through
It is not necessary to form on the peripheral walls of 12, 13, 14, 15 and therefore, the strength of the mast members 11, 12, 13, 14, 15 can be improved. In addition, since man-hours for forming through holes in the mast members 11, 12, 13, 14, 15 are not required in manufacturing, costs can be reduced. Further, the fall prevention devices 51 and 52 are provided with the mast members 11, 12 and 1.
3 and 14, and the fall prevention devices 51 and 52
The wire rope 36 is connected to the mast members 11, 12,
Since there is no need to place it outside 13, 14, 15
Safety is improved. Furthermore, as in the present embodiment, the upper mast members 12, 13, 14, 15 and the lower mast members 11,
Since the fall prevention devices 51 and 52 can be provided on all of the pairs 12, 13, and 14, respectively, the reduction height of the entire telescopic mast 1 when the wire rope 36 is cut can be reduced, and the fall prevention effect can be ensured. In addition, even if the number of steps of the telescopic mast 1 is increased, the fall prevention device can be incorporated into all pairs of the upper mast member and the lower mast member without any trouble.

Further, the elongated bearing hole 53 or the elongated hole 66 is formed.
The brackets 42 and 44 each have a movement-permitting supporting means, and a stopper as a locking body is formed by a swingable lever.
Comprising 57, pulleys 24, 28, 32 or wire rope fixtures
A pulley 24, 28, 32 or wire rope fixing device 45 and a stopper are provided by a support shaft 54 or a fixing pin 67 provided integrally with 45.
Since the urging means is constituted by the spring 62 in conjunction with the spring 57, the fall prevention devices 51 and 52 can be made compact,
Therefore, it is possible to easily provide the stopper receiving portion 63 on the inner surface side of the lower mast members 11, 12, 13, 14 as described above. Further, a bolt is screwed into the side wall of the mast member 11, 12, 13, 14 and one end of the bolt is projected in the inner circumferential direction of the mast member 11, 12, 13, 14 so that the stopper receiving portion is formed.
Since 63 was selected, the wire rope 36 was cut and the fall prevention device 5
The locking portions 59 of the fall prevention devices 51, 52 even when the
Mast members 11, 12, 13, 14
By retracting one end of the bolt protruding from the inner periphery of the bolt to a position where it does not overlap the locking portion 59, or removing the bolt from the mast member 11, 12, 13, or 14, the adjacent lower stopper receiving member The mast members 12, 13, 14, and 15 are lowered until the locking portion 59 comes into contact with the bolt that is the portion 63, and all the lower bolts are weighted one by one with the locking portion 59 as described above. The mast member 1 by retracting it to a position where it does not become necessary or removing it from the mast member 11, 12, 13, 14.
2, 13, 14, and 15 can be lowered to the lower limit position. In this way, the wire rope 36 breaks and the fall prevention device
Even if 51, 52 operates, the mast members 12, 13, 14, 15 can be easily and safely lowered to the lower limit position.
Further, even if the bolt which is the stopper receiving portion 63 is damaged by the impact due to the drop of the mast members 12, 13, 14, 15, it can be replaced.

Next, a second embodiment of the telescopic mast of the present invention will be described with reference to FIGS. The second embodiment is a modification of the stopper receiving portion in the first embodiment. In the second embodiment, a stopper receiving portion 72 as a locking member receiving portion is formed in a long and thin stopper receiving plate 71 made of a component different from the mast member 11 by a plurality of through holes arranged at predetermined intervals in the vertical direction. ing. Stopper receiving plate 71
A receiving piece 73 having a stopper receiving portion 72 formed thereon, a stepped portion 74 vertically bent from one side edge of the receiving piece 73, and a receiving piece 73 opposite from one side edge of the stepped portion 74 The mounting piece 75 is fixed to the inner surface of the peripheral wall of the mast member 11 by welding or bolting. The step 74 is for forming a gap between the receiving piece 73 and the peripheral wall of the mast member 11 for inserting the stopper 57.

As described above, a plurality of stopper receiving portions 72 are formed on one stopper receiving plate 71, and the stopper receiving portions 71 are formed.
Is fixed to the mast member 11, the mast member 11
The stopper receiving portion 72 located inside can be easily configured.

Next, a third embodiment of the telescopic mast of the present invention will be described with reference to FIGS. Parts corresponding to those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Contrary to the first embodiment, the fall prevention device 81 of the third embodiment vertically moves the lower mast member 11, that is, the outer mast member 11 (for example, the first mast member) of the lower and upper mast members 11, 12. Pulley 23,
A stopper 57 and a spring 62 are provided, and a stopper receiving portion 72 is provided on the upper stage, that is, the inner mast member 12 (for example, the second mast member).

The pulley 23 is located above the first mast member 11, and the first pulley 23 is attached to the first mast member 11 by a bracket 82.
The pulley 23 itself is located inside the first mast member 11 through the peripheral wall of the first mast member 11. And
A downward force acts on the pulley 23 that moves up and down by a predetermined range from a wire rope 36 hung on the pulley 23. The stopper 57 is swingably supported on the inner surface side of the first mast member 11, and the transmission receiving portion 58 is in contact with the support shaft 54 of the pulley 23 from below. Further, a spring 62 provided on the inner surface side of the first mast member 11 is located below the stopper 57, and urges the stopper 57 in a direction in which the locking portion 59 side descends. Further, the stopper receiving portions 63 are provided on the outer surface of the peripheral wall of the second mast member 12 so as to protrude vertically at predetermined intervals.

As is clear from the above description, the stopper 57, the spring 62 and the stopper receiving portion 63 of the fall prevention device 81 are located in the gap between the peripheral walls of the first mast member 11 and the second mast member 12. .

Normally, as shown by a chain line in FIG.
The pulley 23 is positioned at the lower end of the movable range in the vertical direction with respect to the first mast member 11 due to the force exerted by the wire rope 36. In this state, the stopper 57 is
The transmission receiving portion 58 side is pressed down by the support shaft 54 of the pulley 23 against the force of the pulley 23, and the stopper 57 of the first mast member 11 and the stopper receiving portion 63 of the second mast member 12 have a projected shape on a horizontal plane. Do not overlap. Therefore, the second mast member 12 can move up and down with respect to the first mast member 11. On the other hand, when the wire rope 36 breaks, the force exerted on the pulley 23 by the wire rope 36 is lost, so that the stopper 57 swings by the bias of the spring 62 as shown by the solid line in FIG. The locking portion 59 is lowered. In conjunction with this, by being pushed up by the transmission receiving portion 58 of the stopper 57, the pulley 23 rises to the upper end side of the movable range with respect to the first mast member 11. In this state, the stopper
The projection shapes of the 57 and the stopper receiving portion 63 on the horizontal plane overlap. Accordingly, as the second mast member 12 falls, the locking portion 59 of the stopper 57 of the first mast member 11 comes into contact with the stopper receiving portion 63 of the second mast member 12 from below. Stops.

As in the third embodiment, the fall prevention device 81 can be provided on the pulley 23 above the mast member 11,
In the third embodiment, the same effects as in the first embodiment can be obtained.

Next, a fourth embodiment of the telescopic mast of the present invention will be described with reference to FIG. The fourth embodiment is a modification of the stopper receiving portion in the third embodiment. In the fourth embodiment, a stopper receiving portion 87 as a locking member receiving portion is formed on a long and thin stopper receiving plate 86 made of a component separate from the mast member 12 by a plurality of through holes arranged at predetermined intervals in the vertical direction. ing. The stopper receiving plate 86 has a flat plate shape, and is fixed to the outer peripheral surface of the mast member 12 at one side edge by welding or bolting.

As described above, a plurality of stopper receiving portions 87 are formed on one stopper receiving plate 86, and the stopper receiving portions 87 are formed.
Is fixed to the mast member 12, the stopper receiving portion 87 can be easily configured.

Next, a fifth embodiment of the telescopic mast of the present invention will be described with reference to FIG. In the fifth embodiment, an upper mast member 12 is provided for a lower mast member 11.
In the fall prevention device 91 for preventing the
7. Two sets of spring 62 and stopper receiving portions 63a and 63b are provided. On the other hand, only one bracket 44 and one pulley 24 are provided. The relationship between the pulley 24, the one stopper 57 and the one stopper receiving portion 63a and the pulley 2
The relationship between 4 and the other stopper 57 and the other stopper receiving portion 63b is the same as that of the first embodiment, but both stoppers 57 are arranged symmetrically on both sides of the mast members 11 and 12. In addition, the stopper receiving portions 63a and 63b
It is located on each of the 12 sides. The stopper receiving portions 63a and 63b on both sides of the mast members 11 and 12 are alternately shifted in the vertical direction.

Therefore, when the wire rope 36 is cut and the mast member 12 falls, depending on the position of the mast member 12 at the start of the fall, any one of the stopper 57 and the stopper receiving portions 63a, 63b has a stopper receiving portion. The stopper 57 is engaged with 63a, 63b, and the mast member 12 stops. And
Since the pitch of the stopper receiving portions 63a and 63b combined with the stopper receiving portions 63a and 63b on both sides can be reduced, the falling distance of the mast member 12 can be reduced. Further, even if one of the two sets of the stopper 57, the spring 62, and the stopper receiving portions 63a, 63b is defective, the other set can prevent the mast member 12 from falling when the wire rope 36 is cut. . Therefore, safety is further improved.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above embodiment, the fall prevention devices 51, 52 are provided between the upper mast members 12, 13, 14, 15 and the lower mast members 11, 12, 13, 14, all. A fall prevention device may be provided only between the mast member and the lower mast member. For example, the fall prevention device may be provided only between the lowermost first mast member and the upper second mast member.

It is also possible to combine the fall prevention device of the first embodiment with the fall prevention device of the third embodiment in one telescopic mast.

In the first embodiment, the bolts serving as the stopper receiving portions 63 are screwed into the mast members 11, 12, 13, and 14. However, each of them can be fixed by welding.

Further, the pulley and the wire rope fixing portion are allowed to move and are supported, a locking member, a structure for interlocking the pulley and the wire rope fixing portion with the locking member, and locking in a direction opposite to the force applied from the wire rope. Specific configurations of the urging means for urging the body and the locking member receiving portion are not limited to those in the above-described embodiment, and various modifications are possible. For example, by attaching a spring serving as an urging means to the pulley and applying a force acting in the opposite direction to the force from the wire rope to the pulley to indirectly urge the stopper serving as the locking body, It is conceivable that the stopper and the stopper are linked to each other by using a link mechanism so that the stopper can move linearly.

In the above embodiment, the number of steps of the telescopic mast 1, that is, the number of the mast members 11, 12, 13, 14, and 15, is 5. However, the number of steps of the telescopic mast is not limited to 5, but is 4 or less. Alternatively, it can be 6 or more. Further, in the above embodiment, two pulleys 21,..., 34 are provided at the upper and lower parts of the mast members 11, 12, 13, 14, respectively. This is for reducing the tension of the wire rope 36, and if only the mast member is to be raised and lowered, one pulley may be provided at each of the upper part and the lower part.

[0056]

According to the first aspect of the present invention, there is provided a thin mast having a plurality of cylindrical mast members that gradually become thinner, and a thick mast member serving as an upper mast member inside a thick mast member serving as a lower mast member. A plurality of mast members are configured to be vertically expandable and contractible by sequentially inserting the members, and wire rope guides provided on the upper and / or lower portions of the mast members and the wire rope guides are wound around the mast members. One end is fixed to the wire rope fixing portion of the uppermost mast member, and the other end is composed of a wire rope connected to a winch via a wire rope guide above the lowermost mast member. And a fall prevention mechanism for preventing the upper mast member from falling against the lower mast member when the wire rope is cut. In telescoping mast with a location,
The fall prevention device is supported by a mast member provided with a movement permitting support unit that supports the wire rope guide or the wire rope fixing unit so as to be movable in a predetermined range with respect to the mast member, A locking member interlocked with the movement of the movable wire rope guide or the wire rope fixing portion, and a direction of a force that the wire rope acts on the locking member via the wire rope guide or the wire rope fixing portion. Urging means for urging the locking body in a direction opposite to that of the mast member provided on the inner surface side of a lower mast member provided with the movement permitting support means, wherein the locking body is Since the locking member and the locking member receiving portion whose projection shape on the horizontal plane overlap with each other in the state of being moved by the bias are provided, it is not necessary to form a through hole for passing the locking member in the peripheral wall of the mast member. It makes possible to improve the strength of the mast member. In addition, since the fall prevention device is located inside the mast member and the wire rope does not need to be located outside the mast member to constitute the fall prevention device, safety is improved.

According to the stretchable mast of the second aspect of the present invention, there is provided a plurality of cylindrical mast members which gradually become thinner, and a narrow mast member which becomes an upper mast member inside a thick mast member which becomes a lower mast member. The mast members are sequentially inserted, and the plurality of mast members are configured to be able to expand and contract in the vertical direction, and wire rope guides provided on the upper and / or lower portions of the mast members and wrapped around these wire rope guides. A plurality of mast members, one end of which is fixed to the wire rope fixing portion of the uppermost mast member and the other end of which is connected to a winch via a wire rope guide above the lowermost mast member. A telescopic mechanism for expanding and contracting the entirety, and preventing the upper mast member from falling on the lower mast member when the wire rope is cut. In a telescopic mast provided with a fall prevention device, the fall prevention device is provided with a movement permitting support means for supporting a wire rope guide or a wire rope fixing portion movably within a predetermined range with respect to the mast member; A locking member supported by a mast member provided with a means and interlocked with the movement of the movable wire rope guide or the wire rope fixing portion; and the wire rope via the wire rope guide or the wire rope fixing portion. Are provided on an outer surface side of an upper mast member provided with an urging means for urging the locking body in a direction opposite to a direction of a force acting on the locking body, and an upper stage of the mast member provided with the movement permitting support means. In the state where the locking body is moved by the urging of the urging means, the locking body and the locking body receiving portion whose projection shape on the horizontal plane overlaps with each other. The through hole by need not be formed in the peripheral wall of the mast members, thereby improving the strength of the mast member. In addition, since the fall prevention device is located inside the mast member and the wire rope does not need to be located outside the mast member to constitute the fall prevention device, safety is improved.

Further, like the telescopic mast according to the third aspect of the present invention, all of the pairs of the upper mast member and the lower mast member can be provided with the above-mentioned fall prevention devices, respectively. In this case, the height of the entire telescopic mast can be reduced, and the fall prevention effect can be ensured.

According to the stretchable mast of the fourth aspect, in addition to the effects of any one of the first to third aspects, the locking member, the urging means and the urging means are attached to the upper mast member and the lower mast member. Since two sets of locking body receiving parts are provided and the vertical positions of the locking body receiving parts are shifted from each other in both sets, the falling distance of the upper mast member with respect to the lower mast member when the wire rope is cut is reduced. Even if one of the two sets of the locking body and the locking body receiving portion is defective, it is possible to prevent the upper mast member from dropping on the lower mast member, thereby further improving safety.

Further, according to the fifth aspect of the present invention, the movement permitting support means comprises a bracket having an elongated hole extending vertically and supporting the wire rope guide or the wire rope fixing portion so as to be vertically movable, The locking body is formed of a lever supported by a horizontal support shaft so as to be swingable, and a projection integrally provided on the wire rope guide or the wire rope fixing portion is provided at one end of the support shaft of the lever. The urging means comprises a spring mounted between the other end of the lever from the support shaft and a spring receiving portion provided on a mast member having the bracket. Therefore, the fall prevention device can be made compact, and therefore, it is also possible to provide the locking member receiving portion on the inner surface side or the outer surface side of the mast member as described above. It made possible.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing a first embodiment of a telescopic mast of the present invention.

FIG. 2 is a horizontal sectional view of the same.

FIG. 3 is a vertical cross-sectional view showing the vicinity of a lower portion of the uppermost mast member.

FIG. 4 is an enlarged cross-sectional view showing the vicinity of the stopper receiving portion.

FIG. 5 is a side view of the floodlight using the telescopic mast.

FIG. 6 is an explanatory view of the extension mechanism.

FIG. 7 is a partial longitudinal sectional view showing a second embodiment of the telescopic mast of the present invention.

FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 7;

FIG. 9 is a sectional view taken along the line IX-IX of FIG. 7;

FIG. 10 is a perspective view of the stopper receiving member.

FIG. 11 is a partial longitudinal sectional view showing a third embodiment of the telescopic mast of the present invention.

FIG. 12 is a plan view of the same.

FIG. 13 is a perspective view of a mast member showing a fourth embodiment of the telescopic mast of the present invention.

FIG. 14 is a partial sectional view showing a fifth embodiment of the telescopic mast of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Telescopic mast 11 1st mast member 12 2nd mast member 13 3rd mast member 14 4th mast member 15 5th mast member (mast member of the uppermost stage) 21 Pulley (wire rope guide) 22 Pulley (wire rope guide) ) 23 Pulley (wire rope guide) 24 Pulley (wire rope guide) 25 Pulley (wire rope guide) 26 Pulley (wire rope guide) 27 Pulley (wire rope guide) 28 Pulley (wire rope guide) 29 Pulley (wire rope guide) 30 Pulley (wire rope guide) 31 Pulley (wire rope guide) 32 Pulley (wire rope guide) 33 Pulley (wire rope guide) 34 Pulley (wire rope guide) 35 Pulley ( Wire rope guide) 36 Wire rope 38 Telescopic mechanism 42 Bracket (movable support means) 44 Bracket (movable support means) 45 Wire rope fixture (Y Rope fixing part) 51 Fall prevention device 52 Fall prevention device 53 Bearing hole (long hole) 54 Support shaft (projection) 57 Stopper (locking member, lever) 62 Spring (biasing means) 63 Stopper receiving portion (locking member receiver) 63a Stopper receiving part (locking body receiving part) 63b Stopper receiving part (locking body receiving part) 66 Long hole 67 Fixing pin (projection) 72 Stopper receiving part (locking body receiving part) 81 Fall prevention device 87 Stopper receiving part (locking part receiving part) 91 Fall prevention device

Claims (5)

[Claims] A plurality of cylindrical mast members which gradually become thinner, wherein a thin mast member which becomes an upper mast member is sequentially inserted inside a thick mast member which becomes a lower mast member; The mast member is configured to be vertically expandable and contractable, and wire rope guides provided at the upper and / or lower portions of the mast member, and the wire of the mast member at the top end, which is hung over the wire rope guide and has one end. A telescopic mechanism fixed to a rope fixing part, the other end of which comprises a wire rope connected to a winch via a wire rope guide above a lowermost mast member, for expanding and contracting the plurality of mast members as a whole; A telescopic mast equipped with a fall prevention device that prevents the upper mast member from falling against the lower mast member when the rope is cut The fall prevention device may include a movement-permitting support unit that supports the wire rope guide or the wire rope fixing unit to be movable within a predetermined range with respect to the mast member, and a mast member provided with the movement-permitting support unit. A supported locking member that is interlocked with the movement of the movable wire rope guide or wire rope fixing portion, and the wire rope acts on the locking member via the wire rope guide or the wire rope fixing portion. A biasing means for biasing the locking body in a direction opposite to the direction of the force, and an inner surface side of a lower mast member provided with the movement-permitting support means, are provided on the inner surface side of the mast member. A telescopic mast comprising: the locking body and a locking body receiving portion whose projection shape on a horizontal plane overlaps when the locking body is moved by the urging means. 2. A mast member comprising a plurality of cylindrical mast members which gradually become thinner, wherein a plurality of thin mast members serving as upper mast members are sequentially inserted inside a thick mast member serving as a lower mast member. The mast member is configured to be vertically expandable and contractable, and wire rope guides provided at the upper and / or lower portions of the mast member, and the wire of the mast member at the top end, which is hung over the wire rope guide and has one end. A telescopic mechanism fixed to a rope fixing part, the other end of which comprises a wire rope connected to a winch via a wire rope guide above a lowermost mast member, for expanding and contracting the plurality of mast members as a whole; A telescopic mast equipped with a fall prevention device that prevents the upper mast member from falling against the lower mast member when the rope is cut The fall prevention device may include a movement-permitting support unit that supports the wire rope guide or the wire rope fixing unit to be movable within a predetermined range with respect to the mast member, and a mast member provided with the movement-permitting support unit. A supported locking member that is interlocked with the movement of the movable wire rope guide or wire rope fixing portion, and the wire rope acts on the locking member via the wire rope guide or the wire rope fixing portion. An urging means for urging the locking body in a direction opposite to the direction of the force, and an outer surface of a mast member on an upper stage of the mast member provided with the movement-permitting support means, wherein the locking body is A telescopic mast comprising: the locking body and a locking body receiving portion whose projection shape on a horizontal plane overlaps when the locking body is moved by the urging means. 3. The telescoping mast according to claim 1, wherein the fall prevention device is provided on all pairs of the upper mast member and the lower mast member. 4. An upper mast member and a lower mast member are provided with two sets of the locking body, the urging means, and the locking body receiving portion, and the two sets of the locking body receiving portions are vertically positioned relative to each other. The telescopic mast according to any one of claims 1 to 3, wherein the mast is shifted. 5. The movement permitting support means comprises a bracket having an elongated hole extending vertically and supporting the wire rope guide or the wire rope fixing portion so as to be movable up and down. The lever is pivotally supported by a shaft, and a projection integrally provided on the wire rope guide or the wire rope fixing portion is brought into contact with one end of the lever relative to a support shaft, and the urging is performed. The means is composed of a spring mounted between the other end of the lever from the support shaft and a spring receiving portion provided on a mast member having the bracket. The telescopic mast according to claim 1.