Fall prevention device

Abstract

The present invention provides a fall prevention device in which a horizontal arm can be raised and lowered and can move forward and backward. [Solution] The system comprises a trolley section 2, a scissor link mechanism 4 disposed above the trolley section 2, a horizontal arm 91 supported by the scissor link mechanism 4 and capable of moving forward and backward, a lifting drive device 3 that drives the scissor link mechanism 4 to raise and lower the horizontal arm 91, a safety block 101 that can be connected to the horizontal arm 91, and left and right outriggers 7, 7 provided on the front and rear of the trolley section 2 and capable of moving left and right. When working at height, the lifting drive device 3 raises and lowers the horizontal arm 91 to which the safety block 101 is connected, connecting the safety block 101 to the worker and preventing falls. Furthermore, when storing or transporting on a vehicle, the scissor link mechanism 4 lowers the horizontal arm 91, retracts the horizontal arm 91 and the outriggers 7, so that it does not take up storage space and is easy to move.

Description

Technical Field

[0001] The present invention relates to a fall prevention device for preventing workers from falling when working at height or in similar scenarios. Background Art

[0002] Conventionally, as a fall prevention device for preventing workers from falling when working at height or in similar scenarios, there has been known a fall prevention device for preventing falls during work at height, which comprises: a fork portion that protrudes forward, remains substantially parallel to the floor surface, and can be lifted and lowered; a movable device base provided with wheels; a support column extending vertically from the device base, at least a part of which has a truss structure; and a safety belt attachment portion coupled to the upper end of the support column (see, for example, Patent Document 1).

[0003] The fall prevention device (1) described in Patent Document 1 comprises a device base (10) that can be moved on a floor surface, a support column portion (20) extending upward from the device base (10), and a safety belt attachment portion (30) coupled to the upper end of the support column portion (20). The device base (10) has the structure of a known cargo handling device called a hand lift, pallet jack, or pallet truck, and comprises a fork portion (12) that protrudes forward (on the left front side in Fig. 1), remains substantially parallel to the floor surface, and can be lifted and lowered, a plurality of wheels (14), and a main body portion (16) accommodating a lifting mechanism and the like (see paragraphs

[0016] ,

[0017] of the specification of Patent Document 1 and Fig. 1).

[0004] Furthermore, a packing box (50) is placed and fixed on the fork portion (12), and a rope extending from a safety block (40) attached to the safety belt attachment portion (30) is connected to a full harness type safety belt worn by a worker (60), thereby allowing the worker (60) to safely perform work at height (see paragraph

[0016] of the specification of Patent Document 1 and Fig. 3). Prior Art Documents Patent Documents

[0005] [Patent Document 1] Utility Model Registration No. 3246558 Gazette [Overview of the project] [Problems that the invention aims to solve]

[0006] The fall prevention device described in Patent Document 1 comprises a long support column (20) for working at heights and a horizontal main steel frame (32) fixed to the top of the support column (20) with a safety block (40) attached to its tip. However, because the height of the support column (20) and the length of the main steel frame (32) are constant, there is a problem in that transportation and relocation are time-consuming.

[0007] Therefore, the present invention aims to solve the above problems and provide a fall prevention device in which a horizontal arm can be raised and lowered and can move forward and backward. [Means for solving the problem]

[0008] The fall prevention device according to the present invention is characterized in that, in accordance with claim 1, it comprises a trolley section, a link mechanism disposed above the trolley section, a horizontal arm supported by the link mechanism and capable of moving forward and backward, and a lifting drive device that drives the link mechanism to raise and lower the horizontal arm.

[0009] Furthermore, the fall prevention device according to the present invention may be provided with an outrigger that moves back and forth in the direction of the horizontal arm, in accordance with claim 2.

[0010] Furthermore, the fall prevention device according to the present invention may be provided with a weight means on the side of the trolley section opposite to the outrigger, in accordance with claim 3.

[0011] Furthermore, the fall prevention device according to the present invention, in accordance with claim 4, includes a storage cylinder that slidably houses the base end of the horizontal arm, and the storage cylinder is provided with a sliding member on which the outer surface of the horizontal arm slides.

[0012] Furthermore, the fall prevention device according to the present invention may be provided with a connecting receiving portion on the horizontal arm that can connect to a safety block connector, in accordance with claim 5. [Effects of the Invention]

[0013] According to the invention of claim 1, when working at height, the horizontal arm to which the safety block is attached can be raised and lowered by the lifting drive device, and the safety block can be attached to the worker to prevent falls. Furthermore, when storing or transporting in a vehicle, the horizontal arm can be lowered and the arm can be retracted by the link mechanism.

[0014] According to the invention of claim 2, by extending and using the outriggers, stability is improved against the force that would cause the trolley to tip over due to the load applied to the horizontal arm.

[0015] According to the invention of claim 3, the weight means counteracts the force that would cause the trolley to tip over due to the load applied to the horizontal arm, thereby improving stability.

[0016] The invention according to claim 4 allows the device to be compactly mounted on a transport vehicle or the like and moved by storing the base end of the horizontal arm in a storage cylinder. Furthermore, since the outer surface of the horizontal arm slides against the sliding member when the horizontal arm is extended or retracted, it is possible to prevent the horizontal arm from rattling relative to the storage cylinder and to improve the extension and retraction of the horizontal arm.

[0017] According to the invention of claim 5, a connector for a safety block can be connected to a connecting receiving portion provided on a horizontal arm. [Brief explanation of the drawing]

[0018] [Figure 1] This is a right side view of the scissors link mechanism of Example 1 in an extended state. [Figure 2] This is a right side view of the scissors link mechanism of Example 1 in a folded state. [Figure 3]Fig. 1 is a perspective view of the carriage side in a state where the scissor link mechanism of Embodiment 1 is extended. [Figure 4] Fig. 3 is a longitudinal sectional view of the front side of the carriage of Embodiment 1. [Figure 5] Fig. 6 is a longitudinal sectional view of the rear side of the carriage of Embodiment 1. [Figure 6] Fig. 9 is a perspective view of the front side of the carriage of Embodiment 1 viewed from above. [Figure 7] Fig. 12 is a sectional view of the position fixing means of Embodiment 1. [Figure 8] Fig. 15 is a perspective view of the arm attachment portion of Embodiment 1 viewed from below. [Figure 9] Fig. 18 is a sectional view of the mounting structure of the sliding member of Embodiment 1. [Figure 10] Fig. 21 is an exploded perspective view of the mounting structure of the sliding member of Embodiment 1. [Figure 11] Fig. 24 is a longitudinal sectional view of the locking means of Embodiment 1. [Figure 12] Fig. 27 is a front view of the upper portion of the leg body and the connector of Embodiment 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying Figs. 1 to 12. The embodiments described below do not limit the content of the present invention described in the claims. Furthermore, not all of the configurations described below are necessarily essential requirements of the present invention. In the present embodiment, the left side in Figs. 1 and 2 is defined as the front side of the fall prevention device 1, and the right side is defined as the rear side of the fall prevention device 1; when facing the front side of the fall prevention device 1, the left side is defined as the left side of the fall prevention device 1, and the right side is defined as the right side of the fall prevention device 1 in the following description. Example

[0020] The fall prevention device 1 of the present embodiment includes a carriage portion 2, a lifting drive device 3 disposed inside the carriage portion 2, a scissor link mechanism 4 which is a link mechanism disposed above the carriage portion 2, and an arm attachment portion 5 supported by the scissor link mechanism 4.

[0021] The trolley section 2 comprises a rectangular frame 6, four outriggers 7, 7, 7, 7 located at the four corners of the frame 6 (front left and right, and rear left and right), left and right front wheels 8, 8 located at the lower front of the frame 6, left and right rear wheels 8, 8 located at the lower rear of the frame 6, connecting rods 9 connecting the left and right front wheels 8, 8, connecting rods 9 connecting the left and right rear wheels 8, 8, and four lift arms 10 connected to the frame 6.

[0022] The frame 6 consists of a front frame 11, a rear frame 12, a left frame 13, and a right frame 14, with the lower ends of the left frame 13 and the right frame 14 fixed to the upper surfaces of the front frame 11 and the rear frame 12. As shown in Figure 4, the front frame 11 is provided with two short cylindrical bearing portions 15 that protrude to the rear for connecting the lift arms 10. As shown in Figure 5, the rear frame 12 is also provided with two bearing portions 15 that protrude forward for connecting the lift arms 10.

[0023] The rear bearing section 15 (Figure 5) is positioned close to the left frame 13 and the right frame 14, while the front bearing section 15 is positioned further inward than the rear bearing section 15. This is to ensure that the second resin roller 33 and the pressing section 35, which will be described later, face each other.

[0024] The rear wheel 8, or rear wheel 16, is a so-called caster and can rotate left and right. In contrast, the front wheel 8, or front wheel 17, cannot rotate left and right. Therefore, the fall prevention device 1 in this embodiment is able to change direction using the rear wheel 16.

[0025] As shown in Figure 3 and other figures, the wheel 8 is attached to the lower part of the rectangular cylindrical wheel holder 18. The wheel holder 18 is inserted into rectangular cylindrical insertion rods 19, which are provided at two locations, front and rear, on the outside of the left frame 13 and the right frame 14, respectively, allowing the wheel holder 18 and the insertion rods 19 to move relative to each other up and down. A plate-shaped retaining plate 20 is formed at the upper end of the wheel holder 18 to prevent the wheel holder 18 from coming out of the insertion rods 19. In addition, an annular engaging portion 21 is formed on the upper surface of the retaining plate 20 for inserting a wire or the like when lifting the fall prevention device 1 with a crane or the like.

[0026] The left and right wheel holders 18 are connected by a connecting rod 9 below the insertion rod 19. As shown in Figure 5, the rear connecting rod 9 has a plate-shaped stopper holder 22 that protrudes to the rear, and a stopper 23 that restricts the movement of the fall prevention device 1 is provided at the bottom of the stopper holder 22. The stopper 23 can be raised or lowered by an operator operating a stopper lever 24. When the stopper 23 is lowered, the stopper 23 makes contact with the floor or other surface, restricting the movement of the fall prevention device 1.

[0027] Next, the lift arm 10 will be described with reference to Figure 5. The lift arm 10 has a configuration in which two straight plate-shaped narrow plate sections 25 are placed opposite each other and connected by a rectangular plate-shaped partition section (not shown), and both ends of the narrow plate sections 25 are formed in a semicircular shape that is convex outward. The narrow plate sections 25 are rotatably connected to the bearing section 15 via a mounting shaft 27, with the bearing section 15 in between.

[0028] At the center of the lift arm 10 in the front-rear direction, a first resin roller 29, which is the pivot point of the lift arm 10, is attached to the narrow plate portion 25 via a pivot shaft 32. The first resin roller 29 has a cylindrical shape, and an axial hole (not shown) for inserting the pivot shaft 32 is formed in the center in the diametrical direction.

[0029] When raising and lowering the outrigger 7 and the front outrigger 81 (described later), the first resin roller 29 contacts the upper surface of the connecting rod 9, and the front and rear of the lift arm 10 move up and down with the first resin roller 29 as the pivot point. The first resin roller 29 is rotatably attached to the narrow plate section 25 via the pivot shaft 32, and can roll smoothly on the upper surface of the connecting rod 9 in conjunction with the movement of the lift arm 10.

[0030] A second resin roller 33, which serves as a pressure receiving part, is rotatably attached to the narrow plate section 25 via a receiving shaft 34 at the end of the lift arm 10 opposite the bearing section 15. When the arm mounting section 5 is lowered, the second resin roller 33 is pressed by a pressing part 35 provided on the scissor link mechanism 4, and functions as the point of force application in the so-called lever principle.

[0031] The first resin roller 29 and the second resin roller 33 use the same parts. Furthermore, the mounting shaft 27, the pivot shaft 32, and the receiving shaft 34 also use the same parts. By standardizing parts in this way and reducing the number of part types, manufacturing costs can be kept low.

[0032] The lifting drive device 3 is located inside the frame 6 and is attached to the left frame 13 and the right frame 14. When the scissor link mechanism 4 is retracted, it rises together with the outriggers 7, 81, etc. The lifting drive device 3 is equipped with a hydraulic unit (not shown) including a motor, pump, valve, and tank, and extends and retracts the scissor link mechanism 4 to raise and lower the arm mounting section 5. The fall prevention device 1 is equipped with an operating unit (not shown) for operating the lifting drive device 3.

[0033] Next, the scissor link mechanism 4 will be described based on Figure 1. The scissor link mechanism 4 is a five-stage link mechanism, with five sets of 10 links arranged on the left and right sides, starting from the bottom: the third stage inner link 42 and the third stage outer link 43, the fourth stage inner link 44 and the fourth stage outer link 45, and the fifth stage inner link 46 and the fifth stage outer link 47. The intersections of the inner and outer links, and the connection points between the lower inner link and the upper outer link, are pivotally supported on both sides by pivot shafts 48. The intersections of the second stage inner link 40 and the second stage outer link 41 are pivotally supported on the left and right sides separately by short pivot shafts 49. The number of stages in the scissor link mechanism 4 can be changed as needed.

[0034] The lower end of the first stage inner link 38 is rotatably attached to the inside of the rear ends of the left frame 13 and the right frame 14. A resin lower sliding roller 51, which slides in a lower groove 50 formed on the inside of the left frame 13 and the right frame 14, is rotatably attached to the lower end of the first stage outer link 39. When the scissor link mechanism 4 is folded, the lower sliding roller 51 moves forward, and when the scissor link mechanism 4 is raised, the lower sliding roller 51 moves forward.

[0035] The left and right first-stage inner links 38 and the left and right third-stage inner links 42 are connected by a hydraulic cylinder 52. When this hydraulic cylinder 52 is retracted, the scissor link mechanism 4 is folded, and when the hydraulic cylinder 52 is extended, the scissor link mechanism 4 stands up. The hydraulic cylinder 52 extends and retracts by supplying and receiving pressurized oil to and from the lifting drive device 3.

[0036] As shown in Figures 2 and 8, the arm mounting portion 5 comprises a base portion 61 that is long in the front-rear direction, a left frame 62L and a right frame 62R provided on the left and right lower surfaces of the base portion 61, and a front frame 63 and a rear frame 64 provided on the front and rear of the upper surface of the base portion 61 in the left-right direction. The left frame 62L and the right frame 62R are made of U-shaped steel or the like, and have an upper groove portion 65 formed inside that is open on the left-right central side.

[0037] The upper end of the fifth stage outer link 47 is rotatably attached to the pivot 66 at the rear ends of the left frame 62L and the right frame 62R of the arm mounting section 5. In addition, a resin upper sliding roller 67 that slides in upper grooves 65 formed on the left and right sides of the bottom surface of the arm mounting section 5 is rotatably attached to the upper end of the fifth stage inner link 46. When the scissor link mechanism 4 is folded, the upper sliding roller 67 moves forward, and when the scissor link mechanism 4 is raised, the upper sliding roller 67 moves backward.

[0038] The outriggers 7 can be extended to the left and right, and when used in the extended position, the fall prevention device 1 can be made more stable. Figure 3 shows the outriggers 7 in the extended position. When the outriggers 7 are retracted, the claw portion 79A of the locking member 79 (described later) is inserted into the positioning hole 77 (Figure 3, etc.), and the left and right leg bodies 71, 71 are brought close to the frame 6.

[0039] Each outrigger 7,7,7,7 has an integrated vertical leg body 71 and a horizontal sliding rod 72. The front frame 11 and rear frame 12 are rectangular tubes with open ends, and as shown in Figures 4 to 6, the left and right outriggers 7,7 are slidably inserted into the front frame 11 and rear frame 12 such that the sliding rod 72 of the left outrigger 7 is located behind the right outrigger 7. Therefore, by lifting the leg body 71 and pulling it out to the left and right, the outriggers 7 can move between a retracted storage position and an extended usage position.

[0040] Furthermore, as shown in Figures 6 and 7, the system includes position fixing means 75 for fixing the outriggers 7 in a stowed position and a used position. Each of the outriggers 7 is provided with this position fixing means 75, and it comprises a positioning hole 76 drilled in the upper surface of the front frame 11, and corresponding to the positioning hole 76, drilled in the upper surface of the slide rod 72, a stowed positioning hole 77 corresponding to the stowed position and a used positioning hole 78 corresponding to the used position.

[0041] Furthermore, the position fixing means 75 has the base end of the locking member 79 rotatably connected to the upper surface of the front frame 11 by a pivot 80, and the tip end of the substantially L-shaped locking member 79 is provided with a claw portion 79A that can be inserted into and removed from the positioning holes 76, 77, and 78.

[0042] Therefore, when the storage positioning hole 77 is aligned with the positioning hole 76 in the storage position, the locking member 79 is rotated and the claw portion 79A on the tip side is inserted into the positioning hole 76 and the storage positioning hole 77, thereby positioning the outrigger 7 in the storage position. Similarly, when the use positioning hole 78 is aligned with the positioning hole 76 in the usage position, the locking member 79 is rotated and the claw portion 79A on the tip side is inserted into the positioning hole 76 and the use positioning hole 78, thereby positioning the outrigger 7 in the usage position.

[0043] Front outriggers 81 that move back and forth in the front-rear direction are provided on the front side of the trolley section 2. These front outriggers 81 are provided in pairs on the left and right sides at intervals from each other and include front-rear guide frames 82, 82 fixed to the lower surface of the front frame 11, left and right sliding rods 83, 83 inserted into these left and right guide frames 82, 82 so as to move back and forth in the front-rear direction, left and right connecting rods 84 fixed to the ends of these left and right sliding rods 83, 83, and left and right leg bodies 85, 85 fixed to the left and right ends of the connecting rods 84.

[0044] Furthermore, as shown in Figures 4 and 6, the vehicle is equipped with a mounting structure 86 for attaching the front outrigger 81 to the front of the trolley section 2. In this mounting structure 86, one side of the lower mounting members 87, 87, which have an L-shaped cross-section, are fixed to the side of the guide frame 82, 82 on the left-right central side, and the other side of the lower mounting members 87, 87 are positioned horizontally, with the upper surfaces of these other side surfaces in contact with the lower surface of the front frame 11. Furthermore, the lower surfaces of the other side of the upper mounting members 88, 88, which have an L-shaped cross-section, are also in contact with the lower surface of the front frame 11. With the front frame 11 sandwiched from above and below by the upper mounting member 88 and the lower mounting member 87 in this way, bolts 89, 89 are inserted through holes 88T, 88T drilled in the front and rear of the other side of the upper mounting member 88 and through holes 87T, 87T drilled in the front and rear of the lower mounting member 87, and nuts 90, 90 are screwed onto the ends of these bolts 89, 89, thereby attaching the front outrigger 81 to the left-right central side of the front frame 11.

[0045] Furthermore, as shown in Figure 6, the front outrigger 81 is also provided with a position fixing means 75A, similar to the position fixing means 75. This position fixing means 75A includes a positioning hole 76A drilled in the upper surface of the guide frame 82, and corresponding to the positioning hole 76A, drilled in the upper surface of the slide rod 83, a storage positioning hole 77A corresponding to the storage position and a usage positioning hole 78A corresponding to the usage position. In addition, the base end of the locking member 79 of the position fixing means 75A is rotatably connected to the upper surface of the guide frame 82 by a pivot 80.

[0046] Therefore, by rotating the locking member 79 in the storage position, with the storage positioning hole 77A aligned with the positioning hole 76A, and inserting the claw portion 79A on the tip side into the positioning hole 76A and the storage positioning hole 77A, the front outrigger 81 is positioned in the storage position. In this storage position, as shown in Figure 2, the suspension body 85 retracts to the position of the handle 98 at the tip of the horizontal arm 91 in the stored state, making the front-to-rear dimensions of the device 1 compact and saving space for storage and transport such as loading onto a vehicle. The horizontal arm 91 is a lateral arm and is provided to be able to move back and forth in the front-to-rear direction.

[0047] Similarly, by rotating the locking member 79 in the storage position with the positioning hole 76A aligned with the positioning hole 78A, and inserting the tip claw portion 79A into the positioning hole 76A and the positioning hole 78A, the front outrigger 81 is positioned in the usage position. In this usage position, as shown in Figure 6, the suspension legs 85, 85 extend forward, allowing them to effectively counteract any force that would attempt to tilt the device 1 forward.

[0048] As shown in Figure 8, the lower edges 68,68 of the left frame 62L and the right frame 62R have notches 69,69 (only the notch 69 of the left lower edge 68 is shown) that allow the left and right upper sliding rollers 67,67 to be inserted into and removed from the upper grooves 65,65. Therefore, during assembly, compared to the state in Figure 8, the angle between the upper side of the inner link 46 and the upper side of the outer link 47 is narrowed, the upper sliding roller 67 is inserted into the upper groove 65 through the notch 69, the angle is widened, the upper sliding roller 67 is moved forward, and the arm mounting part 5 is attached to the scissor link mechanism 4.

[0049] Furthermore, by using the fall prevention device 1, a carabiner 102 is connected to the connecting receiver 97, and a weight (not shown) is connected to the hook 105. When the weight is dropped and it is excessively heavy, the impact load applied to the tip of the horizontal arm 91 to stop the fall causes the frames 62L and 62R to deform slightly at the notch 69. This deformation prevents excessive force from being applied to the cylinder 52. Since only the notch 69 of the frames 62L and 62R deforms slightly, only the frames 62L and 62R can be replaced and reused.

[0050] The arm mounting section 5 is provided with a pair of left and right horizontal arms 91, 91 that are rectangular in shape. Left and right storage cylinders 94, 94 that are rectangular in shape are fixed to the left and right sides of the front frame 63 and the rear frame 64, respectively, to house the left and right horizontal arms 91, 91 in a way that allows them to be loosely inserted. The base ends of the horizontal arms 91, 91 can be inserted into the interior of these storage cylinders 94, 94 through their front openings 95, 95.

[0051] Furthermore, as shown in Figure 8, a pair of left and right horizontal arms 91, 91 have connecting members 96 attached to their tips in the left-right direction. At the left-right center of this connecting member 96 is a connecting receiving portion 97 for which a carabiner 102, which is one of the connecting devices of the safety block 101, can be detachably connected. This connecting receiving portion 97 is shaped like a horizontal rod. In addition, vertically elongated rectangular frame-shaped handles 98 are provided at both ends of the connecting member 96, and these handles 98 have vertical rod-shaped gripping portions 99.

[0052] The safety block 101 (Figure 1), also known as a safety block, has a wire rope 104 wound inside the case body 103, and a hook 105, which is the other connecting device, is provided at the end of the wire rope 104 and is detachably connected to the worker's full harness 106.

[0053] Furthermore, when the wire rope 104 is unfurled slowly, the safety block 101 allows the wire rope 104 to be unfurled with little resistance, and when a worker moves in a direction approaching the safety block 101, the wire rope 104 is automatically retracted. Conversely, when the wire rope 104 is unfurled rapidly, the wire rope 104 is locked. As a result, in the event that a worker falls while working at height, the wire rope 104 is locked, ensuring the worker's safety.

[0054] As shown in Figures 8 to 10, a gap 110 is provided between the inner surface of the storage cylinder 94 and the outer surface of the horizontal arm 91 at the tip of the storage cylinder 94, and a sliding member 111 made of synthetic resin is provided in this gap 110 as a rattle prevention member. The outer surface of the horizontal arm 91 is in contact with the flat inner surface 111N of the sliding member 111 in the longitudinal direction when it is installed, and the outer surface of the metal horizontal arm 91 is not in contact with the inner surface of the metal storage cylinder 94. Furthermore, examples of synthetic resins include MC nylon (registered trademark), which has excellent properties such as mechanical strength, heat resistance, wear resistance, impact resistance, chemical resistance, insulation resistance, and voltage resistance.

[0055] The sliding member 111 is cylindrical in shape, and its inner surface 111N and other surfaces in the longitudinal direction are perpendicular to the central axis of the sliding member 111. At the tip of the storage cylinder 94, mounting structures 112 for the sliding member 111 are provided on its four surfaces (top, bottom, left, and right) for attaching the sliding member 111 from the outside.

[0056] The mounting structure 112 includes an insertion hole 113 drilled in the storage cylinder 94, a plate-shaped fixing member 114 fixed to the outer surface of the four sides by welding or the like, a communication insertion hole 115 drilled in the center of the fixing member 114 and communicating with the insertion hole 113, a plate-shaped mounting member 118 fixed to the outer surface of the fixing member 114 by a plurality (4) bolts 116 which are fixing means, and a bolt 117 which is a pressing member that screws into a female screw portion 118M drilled in the center, a through hole 119 drilled in the mounting member 118 into which the bolt 116 is loosely inserted, a nut 120 for preventing loosening that is screwed onto the bolt 117, and a screw portion 114M formed on the outer surface of the fixing member 114 in the mounted state into which the bolt 116 inserted through the through hole 119 screws.

[0057] Then, the bolt 116, which is a pressing member, is screwed into the female screw portion 118M in the center of the mounting member 118, and the tip of this bolt 117 presses against the outer surface 111G of the sliding member 111. The sliding member 111 is made of a material that has a smaller coefficient of friction with the horizontal arm 91 compared to the steel storage cylinder 94, and the coefficient of friction between the outer surface 111G and the outer surface of the horizontal arm 91 is smaller than the coefficient of friction between the inner surface of the storage cylinder 94 and the outer surface of the horizontal arm 91.

[0058] Therefore, when assembling the storage cylinder 94 and the horizontal arm 91, the horizontal arm 91 is positioned and held in the center of the storage cylinder 94, the sliding member 111 is inserted from the outside into the communication insertion hole 115 and the insertion hole 113, the mounting member 118 is attached to the fixing member 114 with a bolt 116, and then the bolt 117, which is a pressing member, is screwed in and the tip of this bolt 117 presses the sliding member 111, pressing this sliding member 111 against the outer surface of the horizontal arm 91.

[0059] Furthermore, the outer surface 111G side of the sliding member 111 is housed in the insertion holes 113 and 115 and is positioned accordingly. Additionally, the position of the horizontal arm 91 inside the housing cylinder 94 can be adjusted using multiple bolts 117.

[0060] By doing so, after inserting the horizontal arm 91 into the center of the storage cylinder 94, the sliding member 111, which is a rattle prevention member, can be placed in the narrow gap 110 between the storage cylinder 94 and the horizontal arm 91, and the bolt 117 can be adjusted to attach the sliding member 111 to the outer surface of the horizontal arm 91 with the desired force.

[0061] The horizontal arm 91 is equipped with a locking mechanism 121 for locking it in the usage position and the storage position. As shown in Figure 11, the locking mechanism 121 has a through hole 122 on the upper surface of the tip side of the storage cylinder 94, and a cylindrical body 123 that communicates with the through hole 122 is fixed to the upper surface in a position projecting outwards. The mechanism includes a locking pin 124 that can be inserted into the cylinder 123 and the through hole 122. The upper surface of the horizontal arm 91 has a usage positioning hole 125 (Figures 1 and 11) and a storage positioning hole 126 (Figures 2 and 11) into which the tip side of the locking pin 124 is inserted in the usage position and the storage position of the horizontal arm 91. The tip of the locking pin 124 has a tapered portion 124S.

[0062] Furthermore, the lock pin 124 includes a flange portion 127 that rests on the upper end of the cylindrical body 123 and a ring portion 128 that acts as a locking portion. Therefore, from the state in which the lock pin 124 is locked in the storage position by the locking means 121, that is, the state in which the tip of the lock pin 124 is inserted into the storage positioning hole 126, the lock pin 124 is removed using the ring portion 128, the horizontal arm 91 is pulled forward using the handle 98, and the lock pin 124 is inserted into the cylindrical body 123 in the usage position, thereby locking the horizontal arm 91 in the usage position.

[0063] The base end of the horizontal arm 91 is provided with a retaining portion 171 to prevent the horizontal arm 91 from coming out of the storage cylinder 94. This retaining portion 171 is formed larger than the outer circumferential surface of the horizontal arm 91, and its upper surface 172 is closer to the inner circumferential surface of the storage cylinder 94 than the left, right, and bottom surfaces. The tip surface 173 of the retaining portion 171 is perpendicular to the length direction of the horizontal arm 91. In Figure 9, the retaining portion 171 is shown as a roughly rectangular cylinder, but the retaining portion 171 may be composed of four plate pieces provided on the top, bottom, left, and right surfaces, with the upper surface 172 being thicker than the other three plate pieces, so that the upper surface 172 is closer to the inner circumferential surface of the storage cylinder 94 than the left, right, and bottom surfaces.

[0064] Therefore, if the horizontal arm 91 is pulled out beyond its operating position, its tip surface 173 will come into contact with the outer circumference of the four sliding members 111, 111, 111, 111, preventing it from being pulled out any further and locking it in place. Furthermore, when a load is applied to the tip side of the horizontal arm 91 while it is locked in the operating position by the locking means 121, the upper surface 172 on the base end side of the horizontal arm 91 will come into contact with the upper inner surface of the storage cylinder 94, preventing the horizontal arm 91 from bending.

[0065] The arm mounting portion 5 is provided with handles 131, 131 for movement operation at its front and rear. These handles 131 are used when moving using the wheels 8, and as shown in Figures 2 and 8, they consist of a horizontal rod 132 which is the handle body in the left-right direction and is provided on the upper side of the storage cylinder 94, a front fixing portion 133 which fixes both ends of the front horizontal rod 132 to the front frame 63, and a rear fixing portion 134 which fixes both ends of the rear horizontal rod 132 to the rear frame 64.

[0066] As shown in Figures 2 and 5, a weight mechanism 141 is attached to the rear frame 12 of the rear of the trolley section 2 by a rear mounting structure 142. This rear mounting structure 142 is configured by arranging a pair of upper mounting members 143, 143 spaced apart from each other on the upper surface of the rear frame 12, fixing a box-shaped weight means 141 to these upper mounting members 143, 143, and sandwiching the rear frame 12 from above and below with a pair of upper mounting members 143, 143 having an L-shaped cross-section and a pair of lower mounting members 144, 144 having an L-shaped cross-section positioned on the lower surface of the rear frame 12 in correspondence with them. Bolts 145, 145 are inserted through holes 143T, 144T drilled in front of and behind the upper mounting members 143 and lower mounting members 144, and nuts 146, 146 are screwed onto the ends of these bolts 145, 145, thereby attaching the weight means 141 to the left-right center side of the rear frame 12.

[0067] Furthermore, the weighting mechanism 141 consists of a hollow box-shaped body 141H with an openable and closable lid 141F, containing a weight (not shown) such as a metal plate. The weight of the weighting mechanism 141 can be adjusted by opening the lid 141F and increasing or decreasing the weight. The weighting mechanism 141 can also be replaced with a weight of a desired weight using the rear mounting structure 142.

[0068] As shown in Figure 3 and other figures, connector mounting sections 151 are provided on the upper parts of the front, rear, left, and right sides of the suspension body 71. These connector mounting sections 151 are formed by fixing a cover plate 152 to the upper part of the suspension body 71 and drilling a vertical female screw section 153 into this cover plate 152. The coupler 154, which is a connector, is attached to the upper part of the suspension body 71 by screwing the male screw section 154N of the coupler 154 into these sections.

[0069] As shown in Figure 12, the coupler 154 comprises one arm portion 156 and the other arm portion 157, whose base ends are connected by a pivot 155 so as to be openable and closable. A male threaded rod 159 is rotatably connected to the tip of the one arm portion 156 by a pivot 158, and a locking portion 157K is provided at the tip of the other arm portion 157 to engage with a nut 160 screwed onto the male threaded rod 159. The short pipe 161 can be fixed to the coupler 154 by sandwiching it between the one arm portion 156 and the other arm portion 157 and tightening the nut 160.

[0070] Then, by connecting the short pipe 161 to the upper part of the outrigger 7's base body 71 using the coupler 154, and connecting this short pipe 161 to a fixed part (not shown) such as the building structure, it is possible to resist forces that would move or lift the fall prevention device 1.

[0071] On the front side of the lower part of the scissor link mechanism 4, a connecting receiving portion 162 is provided, corresponding to the other connecting receiving portion 97. The connecting receiving portion 162 is provided in the left-right center of the pivot shaft 48, which is provided at the connection between the upper ends of the first stage inner link 38 and the first stage outer link 39 and the lower ends of the second stage inner link 40 and the second stage outer link 41. The carabiner 102 (Figure 1), which is the other connecting device of the safety block 101, is detachably connected to the horizontal rod 163 of this connecting receiving portion 162.

[0072] As shown in Figure 3, the left side of the second outer link 41 on the left side is provided with a hook portion 166 for a full harness. This hook portion 166 integrally comprises a rod-shaped hook portion body 167 projecting outward to the left from the left side and a flange-shaped retaining portion 168 provided at the tip of the hook portion body 167. Therefore, the connecting portion (not shown) of the full harness 106 before wearing can be hooked onto the hook portion 166, and the full harness 106 can be attached to the scissor link mechanism 4. The hook 105 of the safety block 101 is detachably connected to the connecting portion of the full harness 106.

[0073] On the lower surfaces of the left and right first-stage inner links 38 and the left and right first-stage outer links 39, there are roughly rectangular pressing portions 35 that press the second resin roller 33 downward when the scissor link mechanism 4 is folded.

[0074] Next, the raising and lowering of the outriggers 7 and 81 will be explained based on Figures 4 and 5. Figures 4 and 5 show the state in which the scissor link mechanism 4 is folded and the arm mounting portion 5 is lowered, with the pressing portion 35 pushing down the second resin roller 33. When the second resin roller 33 is pushed down, the first resin roller 29 comes into contact with the connecting rod 9 and functions as a fulcrum in the lever principle, causing the bearing portion 15 side of the lift arm 10 to lift. Then, the lower rotation restricting portion 28 comes into contact with the bearing portion 15 and lifts the bearing portion 15, causing the outriggers 7 and 81 connected to the bearing portion 15 via the frame 6 to lift. At this time, the wheel holding portion 18 is only inserted through the insertion rod 19 and is not fixed to the frame 6, so the wheel 8 and the wheel holding portion 18 do not rise, and the wheel 8 remains in contact with the floor or other surface.

[0075] As the scissor link mechanism 4 extends and the arm mounting portion 5 rises, the pressing portion 35 rises together with the scissor link mechanism 4 and separates from the second resin roller 33. In this state, the pressing portion 35 is released from pressing against the second resin roller 33, so the weight of the lifting drive device 3 and outriggers 7 and 81 connected to the frame 6 causes the bearing portion 15 side of the lift arm 10 to descend, and the outriggers 7 and 81 lower and touch the floor or other surface.

[0076] In this manner, when the scissor link mechanism 4 is folded, the outrigger 7 is raised and lifted off the floor, allowing the fall prevention device 1 to be easily moved. In this state, the fall prevention device 1 is moved to the place of use, the stopper 23 is lowered to make contact with the floor, and the movement of the fall prevention device 1 is restricted.

[0077] In this manner, the vehicle is moved near the truck bed 108 using the wheels 8,8, and after releasing the positioning in the stored position by the position fixing means 75,75A, the front outrigger 81 is pulled forward and positioned in the usage position by the position fixing means 75,75A, and after releasing the positioning in the stored position by the position fixing means 75,75A, the front and rear outriggers 7 and the front outrigger 81 are manually pulled outwards and positioned in the usage position by the position fixing means 75,75A, while the lock by the locking means 121 is released, the horizontal arm 91 is pulled forward, and locked in the usage position by the locking means 121. In addition, safety blocks 101 are connected to the receiving parts 97,162 on one and the other sides.

[0078] Then, after extending the outriggers 7 and 81, the scissor link mechanism 4 is extended by the lifting drive device 3, causing the pressing section 35 to gradually rise, and the outriggers 7 and 81 to gradually descend under their own weight, until they make contact with the floor or other surface. When the outriggers 7 and 81 are fully in contact with the floor or other surface, the swinging of the fall prevention device 1 is reduced, allowing it to be held stably and enabling safe work.

[0079] When the other receiving part 162 reaches a predetermined height due to the extension of the scissor link mechanism 4, the extension is stopped, the hook 105, which is the other connecting device, is detached from the connecting receiving part 162, and the hook 105 is connected to the full harness 106 worn by the worker. After this, the scissor link mechanism 4 is extended again, and when the arm mounting part 5 reaches a predetermined height, it is stopped.

[0080] Furthermore, as a variation of the method of using the connecting receivers 97 and 162, all outriggers 7 and 81 and the horizontal arm 91 are extended and locked in the usage position, and with the scissor link mechanism 4 folded, one of the connecting devices of the safety block 101, the carabiner 102, is connected to one of the connecting receivers 97. Then, the scissor link mechanism 4 is extended until it reaches a height where the other connecting device, the hook 105, can be easily connected to the other connecting receiver 162. The extension is then stopped, the hook 105 is connected to the other connecting receiver 162, and then the scissor link mechanism 4 is extended again until the arm mounting portion 5 reaches a predetermined height.

[0081] This makes it easier to connect the hook 105 to the other connecting receiver 162, and when the arm mounting part 5 reaches a predetermined height (usage height), the scissor link mechanism 4 stops, and the hook 105, which is the other connecting device, is connected to the full harness worn by the worker on the ground, allowing the worker to climb onto the truck bed 108 or the like and perform work.

[0082] Furthermore, even if a worker working at a height, such as on the back of a truck 108, falls, the safety block 101 will act to prevent them from falling.

[0083] Thus, the fall prevention device 1 is easily moved by the wheels 8 that move up and down relative to the trolley section 2, and the outriggers 7 and 81 provide excellent stability against loads applied to the tip side of the horizontal arm 91.

[0084] As described above, in this embodiment, corresponding to claim 1, the device comprises a trolley section 2, a scissor link mechanism 4 which is a link mechanism disposed above the trolley section 2, a horizontal arm 91 that is supported by the scissor link mechanism 4 and can move back and forth, and a lifting drive device 3 that drives the scissor link mechanism 4 to raise and lower the horizontal arm 91. Therefore, when working at height, the lifting drive device 3 raises and lowers the horizontal arm 91 to which the safety block 101 is attached, and the safety block 101 is attached to the worker, thereby preventing falls. Furthermore, when storing or moving on a vehicle, the scissor link mechanism 4 can lower the horizontal arm 91 and also retract the horizontal arm 91.

[0085] Furthermore, as an effect of the embodiment, the system comprises a trolley section 2, a scissor link mechanism 4 which is a link mechanism disposed above the trolley section 2, a horizontal arm 91 which is a lateral arm supported by the scissor link mechanism 4 and can move forward and backward, a lifting drive device 3 which drives the scissor link mechanism 4 to raise and lower the horizontal arm 91, a safety block 101 which can be connected to the horizontal arm 91, and left and right outriggers 7, 7 which are provided on the left and right sides at the front and rear of the trolley section 2 and can move forward and backward. Therefore, when working at height, the lifting drive device 3 can raise and lower the horizontal arm 91 to which the safety block 101 is connected, and the safety block 101 can be connected to the worker to prevent falls. Also, when storing or moving on a vehicle, the scissor link mechanism 4 lowers the horizontal arm 91, moves the horizontal arm 91 backward, and moves the outriggers 7 backward, so that it does not take up storage space and is easy to move.

[0086] Furthermore, in this embodiment, in accordance with claim 2, a front outrigger 81 is provided, which is an outrigger that moves back and forth in the direction of the horizontal arm 91. By extending and using the front outrigger 81, stability is improved against the force that would cause the trolley section 2 to tip over due to the load applied to the horizontal arm 91.

[0087] Furthermore, as an effect of the embodiment, since a front outrigger 81 that moves back and forth in the front-rear direction is provided on the front side of the trolley 2, by extending the front outrigger 81 forward and using it, stability is improved against the force that tries to tilt the trolley 2 forward due to the load applied to the tip side of the horizontal arm 91.

[0088] Furthermore, in this embodiment, in accordance with claim 3, a weight means 141 is provided on the side opposite to the front outrigger 81 of the trolley section 2. As a result, the weight means 141 counteracts the force that would cause the trolley section 2 to tip over due to the load applied to the horizontal arm 91, thereby improving stability.

[0089] Furthermore, as an effect of the embodiment, since the weight means 141 is provided on the rear side of the trolley 2, the rear weight means 141 counteracts the force that tries to tilt the trolley 2 forward due to the load applied to the tip side of the horizontal arm 91, thereby improving stability.

[0090] Furthermore, in this embodiment, in accordance with claim 4, a storage cylinder 94 is provided to slidably house the base end of the horizontal arm 91, and a sliding member 111 that slides against the outer surface of the horizontal arm 91 is provided on the storage cylinder 94. As a result, by storing the base end of the horizontal arm 91 in the storage cylinder 94, the fall prevention device 1 can be compactly loaded onto a transport vehicle or the like and moved. In addition, since the outer surface of the horizontal arm 91 slides against the sliding member 111 when the horizontal arm 91 is extended or retracted, rattling of the horizontal arm 91 relative to the storage cylinder 94 can be prevented, and the flexibility of the horizontal arm 91 when it is extended or retracted can be improved.

[0091] Furthermore, in this embodiment, in accordance with claim 5, a connecting receiving portion 97 is provided on the horizontal arm 91 to which a carabiner 102, which is a connector for the safety block 101, can be connected. Thus, the carabiner 102 of the safety block 101 can be connected to the connecting receiving portion 97 provided on the horizontal arm 91.

[0092] Furthermore, as an effect of the embodiment, the safety block 101 comprises a carabiner 102 which is one connector, a case body 103 which winds up a wire rope 104 which is a string-like body, and a hook 105 which is the other connector connected to the wire rope 104. The horizontal arm 91 which is an arm is provided with one connecting receiving part 97 to which the carabiner 102 can be connected, and the scissor link mechanism 4 which is a link mechanism is provided with the other connecting receiving part 162 to which the hook 105 can be connected. Therefore, with the scissor link mechanism 4 folded, the carabiner 102 is connected to the one connecting receiving part 97 and the hook 105 is connected to the other connecting receiving part 162, and by extending the scissor link mechanism 4, the horizontal arm 91 rises and the wire rope 104 is unfurled. Then, when the hook 105 rises due to the extension of the scissor link mechanism 4, it stops at a height that makes connection easy, the hook 105 can be detached from the other connecting receiver 162, and the hook 105 can be connected to the worker's full harness or the like, making the connection work of the hook 105 easier.

[0093] As an example of the effects of the embodiment, the front outrigger 81 is provided in a pair on the left and right sides at a distance from the front of the trolley section 2 and comprises front-rear guide frames 82, 82 fixed to the lower surface of the front frame 11, left and right sliding rods 83, 83 inserted into these left and right guide frames 82, 82 so as to be able to move back and forth in the front and rear directions, a left and right connecting rod 84 fixed to the ends of these left and right sliding rods 83, 83, and left and right leg bodies 85, 85 fixed to the left and right ends of the connecting rod 84. Therefore, it can resist forces that would cause the trolley section 2 to tip forward, and the left and right leg bodies 85, 85 can also improve the left and right stability of the trolley section 2.

[0094] Furthermore, since it is equipped with a mounting structure 86 for detachably attaching the front outrigger 81 to the front of the trolley section 2, it can be attached and replaced depending on the operating conditions.

[0095] By attaching left-right connecting members 96 to the ends of a pair of left and right horizontal arms 91, 91, and providing one connecting receiving part 97 in the left-right center of the connecting member 96 to which a carabiner 102, which is one of the connecting devices of the safety block 101, can be detachably connected, the U-shaped structure formed by the connecting members 96 connecting the ends of the horizontal arms 91, 91 allows for strength to be ensured without making the arms into a truss structure or making the cross-sectional shape of the cantilevered horizontal arm 91 unnecessarily large, as in conventional designs.

[0096] Furthermore, it is equipped with a mounting structure 112 for attaching the sliding member 111 from the outside, and includes an insertion hole 113 drilled in the storage cylinder 94, a plate-shaped fixing member 114 fixed to the outer surface of the storage cylinder 94, a communication insertion hole 115 drilled in the center of the fixing member 114 and communicating with the insertion hole 113, and a plate-shaped mounting member 118 fixed to the outer surface of the fixing member 114 by a plurality (4) bolts 116 which are fixing means, and a bolt 117 which is a pressing member that screws into a female screw portion 118M drilled in the center. The mounting member 118 is equipped with a through hole 119 into which the bolt 116 is loosely inserted, a nut 120 for preventing loosening that is screwed onto the bolt 117, and a threaded portion 114M formed on the outer surface of the fixing member 114 in the mounted state, into which the bolt 116 inserted through the through hole 119 is screwed. Therefore, when assembling the storage cylinder 94 and the horizontal arm 91, the horizontal arm 91 can be positioned and held with the storage cylinder 94 inserted in the center, and the sliding member 111 can be attached from the outside. Conversely, the sliding member 111 and other components can be removed after installation, making it easy to replace them when they are worn out or damaged. Furthermore, the synthetic resin sliding member 111 has greater elasticity than the steel horizontal arm 91 and steel storage cylinder 94, and is more elastically deformable than steel. Therefore, when a fall impact force is applied to the horizontal arm 91, using the elastic sliding member 111 allows the impact force to be absorbed by elastic deformation, reducing damage to the horizontal arm 91 and storage cylinder 94. Also, while a steel storage cylinder 94 may rust after long-term use, using a rust-resistant material, such as the synthetic resin sliding member 111, prevents rust and allows for long-term use. In addition, the sliding member 111 enhances the extension and retraction of the horizontal arm 91, making it easier to move the horizontal arm 91 between the usage position and the storage position manually.

[0097] Furthermore, since it is equipped with a locking mechanism 121 for locking the horizontal arm 91, the horizontal arm 91 can be locked in both the usage position and the storage position. In addition, since the arm mounting portion 5 is provided with handles 131, 131 on the front and rear, the fall prevention device 1 can be moved on the wheels 8 by operating the handle 131.

[0098] Since the weight means 141 is attached to the rear frame 12 at the rear of the bogie section 2 by the rear mounting structure 142, it can be attached and replaced.

[0099] Furthermore, connector attachment points 151 are provided on the upper parts of the front, rear, left, and right sides of the aforementioned suspension body 71. A coupler 154, which is a connector, is attached to the upper part of the suspension body 71, and a short pipe 161 is connected to this coupler 154. By connecting this short pipe 161 to an external anti-lifting member such as a building frame or heavy object, it is possible to resist forces that attempt to move or lift the fall prevention device 1.

[0100] Furthermore, since the outer link is provided with a hook portion 166 for a full harness, the connecting portion (not shown) of the full harness 106 can be hooked onto the hook portion 166, and the full harness 106 can be attached to the scissor link mechanism 4.

[0101] Furthermore, after connecting one of the safety block 101's connecting devices, the carabiner 102, to one of the connecting receivers 97, the scissor link mechanism 4 is extended until it reaches a height where the other connecting device, the hook 105, can be easily connected to the other connecting receiver 162. At this point, the extension is stopped, and the hook 105 can be connected to the other connecting receiver 162.

[0102] In this embodiment, the fall prevention device 1 comprises a trolley section 2, a lifting drive device 3 disposed inside the trolley section 2, a scissor link mechanism 4 which is a link mechanism disposed above the trolley section 2, and an arm mounting section 5 supported by the scissor link mechanism 4, wherein the trolley section 2 comprises a frame 6 which is a substantially rectangular frame section, outriggers 7 which are support sections erected downward at the four corners of the frame 6, and a lift arm 10 connected to the frame 6 which raises and lowers the frame 6 and the outriggers 7 around a pivot axis 32, and the fall prevention device 1 The scissor link mechanism 4 comprises wheels 8 which are wheel sections that allow movement, and a connecting rod 9 which is a connecting section that connects the left and right wheels 8. The scissor link mechanism 4 is provided with a pressing section 35 that presses the lift arm 10 downward. The lift arm 10 is provided with a second resin roller 33 which is a pressing receiving section that is positioned opposite and in contact with the lower end of the pressing section 35, and a first resin roller 29 which is a pivot point that is positioned in contact with the connecting rod 9. Thus, a movable fall prevention device 1 can be provided that allows the outrigger 7 to be raised and lowered in accordance with the raising and lowering of the scissor link mechanism 4.

[0103] Furthermore, the present invention is not limited to the above embodiments, and various modifications can be implemented within the scope of the gist of the invention. For example, although the fall prevention device in the embodiment is moved by human power, it may be a motor-driven self-propelled type. It is also possible to mount safety devices such as a vehicle tilt warning device or an overload prevention device. Furthermore, the horizontal arm may be angled upward or downward. The horizontal arm may also be made to move back and forth toward the rear of the trolley, or to move back and forth to one side. Furthermore, although a cylindrical sliding member was exemplified in the embodiment, the shape of the sliding member can be appropriately selected, such as a rectangular prism, and the insertion hole should be formed according to the shape of the sliding member. [Explanation of Symbols]

[0104] 1. Fall prevention device 2 Bogie section 3. Lifting drive device 4. Scissors link mechanism (link mechanism) 5. Arm mounting section 7 Outriggers 81 Front outrigger (outrigger) 91 Horizontal arm (arm in the horizontal direction) 94 Storage cylinder 101 Safety Block 102 Carabiner (one of the connecting parts) 105 Hook (the other connector) 111 Sliding member (anti-loosening member)

Claims

1. The bogie section, A link mechanism is provided above the aforementioned bogie section, A horizontal arm supported by the aforementioned link mechanism and capable of moving forward and backward, A fall prevention device characterized by comprising a lifting drive device that drives the link mechanism to raise and lower the horizontal arm.

2. The fall prevention device according to claim 1, further characterized by being provided with an outrigger that moves back and forth in the direction of the horizontal arm's advancement and retraction.

3. The fall prevention device according to claim 2, characterized in that a weight means is provided on the side of the trolley portion opposite to the outrigger.

4. The fall prevention device according to claim 1 or 2, comprising a storage cylinder that slidably houses the base end of the horizontal arm, and a sliding member provided on the storage cylinder on which the outer surface of the horizontal arm slides.

5. The fall prevention device according to claim 1, characterized in that the horizontal arm is provided with a connecting receiving portion to which a safety block connector can be connected.

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