Fall prevention device and working method at high-place

Abstract

To provide a fall prevention device capable of securing workability even for work in a narrow working place of a work machine.SOLUTION: A fall prevention device (1) according to the present invention is used by being arranged around a work machine such as a crane (100) and prevents a worker (50) from falling from a work site, and includes a hanging member (13) that locks a mounting fixture (51) attached to the worker (50) and is movable, and a work floor (4) extending along a moving direction of the hanging member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fall prevention device for working at height and a method for working at height. [Background technology]

[0002] When performing maintenance or repair work on work machinery such as cranes, if the work involves working at a height of, for example, 2m or more, measures must be taken to prevent workers from falling.

[0003] As a fall prevention measure of this kind, Patent Document 1 describes a support for a fall protection device that is attached to the forks of a forklift truck. This support is composed of a locking member to which the hook of a safety belt lanyard is locked and a connecting member into which the fork of the forklift truck is inserted. By connecting this support to a forklift truck, the forklift truck can be used as a base to fix the support and as a solid structure to which the safety belt lanyard is locked. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-188009 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the fall prevention device described in Patent Document 1 does not ensure workability in narrow work spaces such as the top of a boom of a crane, and there is room for improvement.

[0006] Therefore, a main object of the present invention is to provide a fall prevention device that can ensure workability in a narrow working space of a work machine. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a representative present invention is a fall prevention device that is placed around a work machine and used to prevent a worker from falling, and is characterized by comprising a movable suspension member that engages the attachment worn by the worker and a work platform that extends along the direction of movement of the suspension member.

[0008] According to the present invention, it is possible to obtain a fall prevention device that can ensure better workability in narrow working spaces for work machines. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a fall prevention device according to an embodiment, seen from the front. [Figure 2] FIG. 2 is a perspective view of the fall prevention device as seen from the rear. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 4 is an explanatory diagram of a wire and a hanging member. [Figure 7] FIG. 10 is an explanatory diagram showing a height adjustment mechanism for the work platform. [Figure 8] FIG. 10 is an explanatory diagram of an auxiliary scaffold. [Figure 9] FIG. 2 is a perspective view showing a state in which a fall prevention device is arranged around a work machine. [Figure 10] FIG. 2 is a plan view showing the fall prevention device and the work location of the work machine. [Figure 11] FIG. 2 is a side view showing the fall prevention device and the work location of the work machine. [Figure 12] 1 is a flowchart showing the steps of a method for working at height according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] Figure 1 is an oblique view of the fall prevention device of the embodiment seen from the front, Figure 2 is an oblique view of the fall prevention device seen from the rear, Figure 3 is a front view of the fall prevention device, Figure 4 is a side view of the fall prevention device, Figure 5 is a plan view of the fall prevention device, Figure 6 is an explanatory diagram of the wire and hanging member, Figure 7 is an explanatory diagram showing the height adjustment mechanism of the work platform, and Figure 8 is an explanatory diagram of the auxiliary scaffolding.

[0012] As shown in Figures 1 to 5, the fall prevention device 1 of the embodiment comprises a pair of leg members 2, a pair of base members 3 provided at the lower ends of the leg members 2, a work platform 4 supported by the pair of leg members 2, a ladder 5 which serves as an elevator for the work platform 4, and handrails 6 provided around the work platform 4 and the ladder 5.

[0013] The pair of leg members 2 and the pair of base members 3 are connected by a plurality of horizontal supports 7. The fall prevention device 1 is a highly rigid structure formed by the leg members 2, base members 3, horizontal supports 7, etc. In the following description, the axial direction of the leg members 2 is defined as the up-down direction, the axial direction of the base members 3 as the front-rear direction, and the axial direction of the horizontal supports 7 as the left-right direction.

[0014] The leg member 2 is a structure in which two vertical struts 8 extending in the up-down direction are connected by multiple reinforcing diagonal members 9. A triangular diagonal member 10 is attached to the upper end of the leg member 2, and the top of this diagonal member 10 protrudes forward from one of the vertical struts 8. A connecting member 11 extending in the left-right direction is installed between the diagonal members 10 of the pair of leg members 2. Wires 12 are fixed to both ends of the connecting member 11, and a suspension member 13 is movably supported by these wires 12. This allows the suspension member 13 to move in the left-right direction (horizontal direction) using the wire 12 along the connecting member 11 as a guide member. In this embodiment, two wires 12 are arranged parallel to each other with a gap in the front-to-rear direction, and a suspension member 13 is individually supported by each wire 12.

[0015] The suspending member 13 is a retractable fall prevention device known as a safety block. As shown in Figure 6, the suspending member 13 has a main body 13a that incorporates a take-up reel and the like, and a connecting fitting 13b provided on the upper part of the main body 13a is movably supported by the wire 12. A strap 13c of a predetermined length extends from the main body 13a, and the strap 13c has a hook 13d at its tip. The strap 13c is always wound around the main body 13a, but if the strap 13c is suddenly pulled out, a locking mechanism within the main body 13a will activate and stop the strap 13c from being pulled out.

[0016] The base members 3 are made of steel that supports the leg members 2 and extends in the front-to-rear direction, and function as outriggers for the fall prevention device 1. The base members 3 are provided with tires 14 with locking functions at two locations, the front and rear, and a total of four tires 14 are provided on the pair of left and right base members 3. The fall prevention device 1 is movable using these four tires 14.

[0017] Furthermore, the base member 3 is provided with jacks 15 at two locations, the front and rear ends, and the pair of left and right base members 3 is provided with jacks 15 at four locations, front, back, left and right. These four jacks 15 constitute an inclination adjustment mechanism, and can adjust the inclination of the base member 3 with respect to the installation surface. In other words, when the place where the fall prevention device 1 is installed is an inclined surface, the pair of base members 3 can be made horizontal by extending the jack 15 located on the lower side of the inclined surface. This makes it possible to keep the work platform 4 supported by the leg members 2 in a horizontal position, even when the fall prevention device 1 is installed on an inclined surface.

[0018] A pair of engagement holes 3a are provided in the bottom of the base member 3, and a pair of engagement holes 7a are also provided in the horizontal support member 7 that connects the rear ends of the left and right base members 3. These engagement holes 3a, 7a are used to receive the forks of a forklift truck. A self-propelled unit 16 is also attached to the horizontal support member 7 that connects the rear ends of the left and right base members 3, and this self-propelled unit 16 is self-propelled using an electric motor as its drive source. This allows the fall prevention device 1 to be moved in three ways: manually, by forklift truck, or by the self-propelled unit 16.

[0019] The work platform 4 is a rectangular plate-like member that extends horizontally along the movement direction (left-right direction) of the hanging member 13, and is fixed to a pair of leg members 2 via a lift floor 17. Note that "extending horizontally" does not only mean horizontal in the strict sense, but also includes extending with a slight inclination. The work platform 4 may be formed as a single member and extend in the movement direction (horizontal direction), or it may be formed by connecting multiple members and extend in the movement direction (horizontal direction) with the multiple members.

[0020] The fall prevention device 1 is equipped with a lifting device 18 that enables the working platform 4 to move up and down, and the lifting device 18 is installed at the lower position of each of the left and right leg members 2. The lifting device 18 has a rope 19 connected to the lifting floor 17, and a reel 20 that winds and unwinds the rope 19. By driving the reel 20 to wind the rope 19, the lifting floor 17 rises integrally with the working platform 4, and by unwinding the rope 19, the lifting floor 17 descends integrally with the working platform 4.

[0021] The fall prevention device 1 also includes a height adjustment mechanism 21 that adjusts the vertically movable work platform 4 to different height positions on the leg members 2, and the height adjustment mechanisms 21 are provided at four locations on the left and right leg members 2.

[0022] As shown in FIG. 7 , the height adjustment mechanism 21 includes a lock pin 22, a swing lever 23 that drives the lock pin 22, and a pair of operating cords 24a and 24b that operate the swing lever 23. The lift floor 17 is provided with a plurality of lock holes (not shown) spaced at predetermined intervals in the vertical direction. When the lock pin 22 engages with one of these lock holes, the lift floor 17, which supports the work platform 4 at that position, is fixed at a predetermined height position on the leg member 2. The swing lever 23 is rotatably supported on a support shaft 23a below the lock pin 22 and has a bifurcated portion that engages with the protrusion 22a of the lock pin 22. The swing lever 23 rotates in either the forward or reverse direction around the support shaft 23a by selectively pulling down one of the pair of operating cords 24a and 24b. Specifically, by pulling down one of the operating cords 24a, the swing lever 23 rotates in one direction around the support shaft 23a, driving the lock pin 22 in a direction that disengages from the lock hole. Furthermore, by pulling down the other operating string 24b, the swing lever 23 rotates in the other direction around the support shaft 23a, driving the lock pin 22 in the direction of engagement with the lock hole.

[0023] In this way, the fall prevention device 1 is equipped with the lifting device 18 that enables the working platform 4 to be moved in the vertical direction, and the height adjustment mechanism 21 that adjusts the working platform 4 to different height positions on the leg member 2, and therefore the lifting device 18 and the height adjustment mechanism 21 can be used to easily and reliably fix the working platform 4 to a target height position on the leg member 2. That is, when fixing the working platform 4 to a target height position on the leg member 2, first, one of the operating cords 24a is pulled down to release the lock pin 22 from the lock hole, and in this state the working platform 4 is moved up and down by the lifting device 18 to align it to the target height, and then the other operating cord 24b is pulled down to engage the lock pin 22 with the lock hole, thereby fixing the working platform 4 to the target height position.

[0024] A step 25 is disposed at the rear left side of the work platform 4, and this step 25 is supported by the lift floor 17. In addition, a step 26 is disposed at the rear right side of the work platform 4, and this step 26 is also supported by the lift floor 17. These step 25, 26 are adjacent to the rear side of the work platform 4, and the step 25, 26 and the work platform 4 form a flat floor surface. Furthermore, handrails 6 are erected around these step 25, 26, and handrails 6 are also erected at the rear of the work platform 4 and on the sides of the ladder 5.

[0025] The upper end of the ladder 5 is connected to one of the footboards 25, so that a worker can get on to the work platform 4 from the ladder 5 via the footboard 25. The lower end of the ladder 5 is connected to a slide body 27 that is slidably supported on the horizontal support 7 at the lowest end of the leg member 2, so that the ladder 5 moves up and down in conjunction with the up and down movement of the work platform 4 (see the two-dot chain line in Figure 3). Although the specific configuration is omitted, even if the vertical position of the ladder 5 changes, each step of the ladder 5 always maintains a horizontal position, so that a worker can effectively use the ladder 5 regardless of the height position of the work platform 4.

[0026] Above the other footboard 26, a chain block 28 supported by the right leg member 2 is installed. The chain block 28 has a hoisting rope 28a, which has a hook attached to the end thereof. The hoisting rope 28a is capable of hoisting a load from the bottom end of the ladder 5 to the top end of the ladder 5. In other words, the hoisting rope 28a can hoist a load from the installation surface (ground) to a position outside the work platform 4 that is higher than the horizontal plane of the work platform 4. This allows a worker on the footboard 26 to use the chain block 28 to hoist a load on the ground and easily carry it onto the work platform 4.

[0027] The fall prevention device 1 is equipped with multiple auxiliary scaffolds 29 that can be removed from the work platform 4. The fall prevention device 1 is used by being placed around the work machine, but the top and sides of the work object are not necessarily flat, and if there are protrusions on the side of the work object, a large gap will be created between the front of the work platform 4 and the side of the work object. The auxiliary scaffolds 29 are components for reducing the gap that occurs between the work object and the work platform 4, and are attached to the front part of the work platform 4 so as to protrude outward from the floor surface of the work platform 4. In this embodiment, the height of the auxiliary scaffolds 29 is set to be approximately the same as the floor surface of the work platform 4 in consideration of workability, but the two do not necessarily have to be at the same height. In other words, the auxiliary scaffolds 29 may be attached to the work platform 4 with a slight step therebetween.

[0028] As shown in FIG. 8 , a groove receiving portion 30 with an open top is provided between the lift floor 17 and the front surface of the working floor 4, and a plurality of these groove receiving portions 30 are arranged in a row along the longitudinal direction of the working floor 4. The auxiliary scaffolding 29 has a wedge shape that gradually becomes shorter from the rear end to the front end, and an engaging portion 29a is formed at the rear end. The auxiliary scaffolding 29 is attached to a predetermined position on the front side of the working floor 4 by inserting this engaging portion 29a into the groove receiving portion 30 from above. In other words, the auxiliary scaffolding 29 is detachably attached to the working floor 4. The auxiliary scaffolding 29 also has a groove-shaped holding portion 29b that can be hooked onto the handrail 6. Unused auxiliary scaffolding 29 that is not attached to the front surface of the working floor 4 is stored by using this holding portion 29b to hang on the handrail 6 around the working floor 4.

[0029] Next, a method of using the fall prevention device 1 according to the embodiment will be described with reference to FIGS.

[0030] Figure 9 is an oblique view showing the state in which a fall prevention device is placed around a work machine, Figure 10 is a plan view showing the fall prevention device and the work location of the work machine, Figure 11 is a side view showing the fall prevention device and the work location of the work machine, and Figure 12 is a flowchart showing the steps of the high-altitude work method of the embodiment.

[0031] As shown in Figures 9 to 11, a crane 100, which is an example of a work machine, includes a crawler-type running body 101, a revolving body 102 mounted on the running body 101, a boom 103, etc. When performing various tasks such as maintenance or repair on the boom 103 of such a crane 100, first, fall prevention devices 1 are placed around the crane 100 (S1 in Figure 12).

[0032] In this case, the fall prevention device 1 can be moved by any one of three methods: manually, by forklift truck, or by self-propelled unit 16, or by a combination of these. If the height of the work platform 4 is significantly different from that of the work site, the lifting device 18 and height adjustment mechanism 21 are used to align the work platform 4 so that it is at approximately the same height as the work site (S2 in Figure 12). Furthermore, if the fall prevention device 1 is placed on sloping ground, the jack 15 located on the lower side of the slope of the sloping ground is extended to adjust the work platform 4 to a horizontal position.

[0033] Next, worker 50 wearing a safety belt climbs onto work platform 4 using ladder 5 (S3 in FIG. 12). A rope-type lanyard 51 is attached to the safety belt worn by worker 50 (see FIG. 11). Here, lanyard 51 generally refers to the "lifeline portion of a fall arrest device" consisting of a synthetic fiber rope or strap with attached components such as a hook, D-ring, reel, shock absorber, and extension adjuster, and is an example of the harness of the present invention. However, the harness of the present invention is not limited to this and includes any harness worn by worker 50 that can prevent worker 50 from falling.

[0034] A worker 50 who has climbed onto the work platform 4 hooks the lanyard 51 of the safety belt onto the hook 13d of the suspending member 13 (S4 in FIG. 12). At this point, the worker 50 is connected to the suspending member 13 and is in a safe state, and can move freely on the work platform 4 and the footboards 25, 26. If it is necessary to carry in cargo from the ground, the chain block 28 is operated to lift the cargo and carry it onto the work platform 4.

[0035] It is also possible for two workers 50 to get onto the work platform 4 and have their lanyards 51 individually hooked to the two suspending members 13. In this case, the two wires 12 that guide the movement of the suspending members 13 are arranged parallel to each other with a gap between them in the front-to-rear direction, so the two workers 50 can pass each other freely on the work platform 4.

[0036] Next, the worker 50 attaches auxiliary scaffolding 29 to predetermined locations on the front side of the work platform 4 so as to reduce the gap between the boom 103, which is the work location, and the front of the work platform 4 (S5 in FIG. 12). That is, because there are protrusions in several locations on the side of the boom 103 facing the work platform 4, the worker 50 attaches auxiliary scaffolding 29 to the front side of the work platform 4 at positions that avoid these protrusions, thereby arranging multiple auxiliary scaffoldings 29 to fill the gap between the work platform 4 and the boom 103, as shown in FIG. 10. In this case, the auxiliary scaffolding 29 can be attached to the groove receiving portion 30 of the work platform 4 from above, so the auxiliary scaffolding 29 can be easily attached without being obstructed by the boom 103.

[0037] Thereafter, with the lanyard 51 still attached to the suspending member 13, the worker 50 moves from the work platform 4 to the work location on the boom 103 and performs the prescribed work such as maintenance or repair (S6 in FIG. 12). Here, as shown in FIG. 11, the suspending member 13 is provided in a position close to the front side of the work platform 4, so that even when attaching or detaching the boom 103, for example, the boom 103 can be raised and lowered in a position close to the fall prevention device 1 without being obstructed by the suspending member 13.

[0038] After completing work at the work site, the worker 50 returns to the work platform 4, removes the lanyard 51 from the hook 13d of the suspending member 13 (S7 in FIG. 12), and then descends to the ground using the ladder 5 (S8 in FIG. 12). In this way, the series of high-altitude work operations is completed.

[0039] As described above, the fall prevention device 1 of this embodiment is used by being placed around a work machine such as a crane 100, and is equipped with a suspending member 13 that can engage the lanyard 51 of the safety belt worn by the worker 50, a wire 12 that supports the suspending member 13 so that it can move horizontally, and a work platform 4 that extends along the movement direction of the suspending member 13, thereby ensuring safety and workability even when working in a narrow work space with a work machine.

[0040] In addition, two wires 12 are provided parallel to each other, and a hanging member 13 is movably supported on each of these wires 12, so that two workers 50 can pass each other freely on the work floor 4 while ensuring safety, thereby improving workability.

[0041] In addition, the work floor 4 is provided with a plurality of auxiliary scaffoldings 29 that can be removed, and these auxiliary scaffoldings 29 are attached so that they protrude outward at approximately the same height as the floor surface of the work floor 4. Therefore, even if the top or sides of the work object are not flat, the auxiliary scaffoldings 29 can fill in any gaps that arise between the work object and the work floor 4 depending on the shape of the work object, and the worker 50 can easily move back and forth between the work floor 4 and the work location.

[0042] In addition, multiple groove receiving portions 30 with openings on the upper surface are provided on the front side of the work floor 4, and the auxiliary scaffolding 29 has an engagement portion 29a that is inserted into the groove receiving portion 30 from above, so that the auxiliary scaffolding 29 can be easily attached / detached without being obstructed by the work object.

[0043] In addition, handrails 6 are erected around the periphery of the work floor 4, and the auxiliary scaffolding 29 is formed with groove-shaped holding portions 29b that can be hooked onto the handrails 6, so that the auxiliary scaffolding 29 can be stored on the handrails 6 when not in use, and when in use, the auxiliary scaffolding 29 can be removed from the handrails 6 and attached to the front side of the work floor 4.

[0044] Furthermore, the fall prevention device 1 according to this embodiment is equipped with a pair of leg members 2 that support the working platform 4, and a lifting device 18 that enables the working platform 4 to move up and down relative to these leg members 2, so that the working platform 4 can be adjusted in height by using the lifting device 18 to approach the height of the working location of the work machine. Note that the height position need only be adjusted to an extent that does not impair workability, and does not have to be adjusted to the exact same height position.

[0045] Furthermore, the work platform 4 is provided with a height adjustment mechanism 21 that adjusts the work platform 4 to a number of different height positions on the leg member 2. This height adjustment mechanism 21 has a lock pin 22 that can fix the work platform 4 to the leg member 2, and an operating part (a swivel lever 23 and a pair of operating cords 24a, 24b) that operates the lock pin 22 to fix / unfix it, so that the height of the work platform 4 can be easily and reliably adjusted according to the height of the work location of the work machine.

[0046] In addition, the leg member 2 has a pair of base members 3 at its lower end that face each other across the work floor 4, and each of these pair of base members 3 has tires 14 with a locking function, allowing the fall prevention device 1 to be easily moved.

[0047] In addition, jacks 15 are provided at four locations on the front, back, left and right of the pair of base members 3, and these jacks 15 form an inclination adjustment mechanism that can adjust the inclination relative to the installation surface, so that even when the fall prevention device 1 is placed on an inclined surface, the work platform 4 supported by the leg members 2 can be kept in a horizontal position.

[0048] In addition, the fall prevention device 1 of this embodiment is equipped with a ladder 5 that serves as an elevator to the work platform 4, and this ladder 5 moves up and down in conjunction with the up and down movement of the work platform 4, so that workers can use the ladder 5 to climb up and down to the work platform 4 regardless of the height position of the work platform 4.

[0049] In addition, the fall prevention device 1 of this embodiment is equipped with a chain block 28 that drives the hoisting rope 28a, so even when work requires heavy tools or parts, these items can be easily lifted onto the work platform 4 using the hoisting rope 28a without having to be carried by hand.

[0050] It should be noted that the above-described embodiments are merely examples for explaining the present invention, and are not intended to limit the scope of the present invention to these embodiments. Those skilled in the art can implement the present invention in various other forms without departing from the gist of the present invention.

[0051] For example, in the above embodiment, a crawler-type crawler crane was used as an example of a work machine in which the fall prevention device of the present invention is used, but the work machine is not limited to this and may be other cranes such as rough terrain cranes, wheel cranes, foundation machines, or work machines such as shovels, asphalt finishers, unloaders, forklifts, etc. [Explanation of symbols]

[0052] 1 Fall protection device 2 Leg members 3 Base material 4 Work Platform 5 ladder 6 Handrails 7 Horizontal struts 8 Vertical struts 9 Reinforcing diagonal members 10 Diagonals 11 Connecting member 12 wire 13 Hanging members 14 Tires 15 Jack 16 Self-propelled units 17 Liftable Floors 18 Lifting device 19 Rope 20 reels 21 Height adjustment mechanism 22 Lock pin (fixing member) 23 Swing lever (operation part) 24a, 24b Operation string (operation part) 25,26 treadle 28 Chain Block 28a Hoisting rope 29 Auxiliary scaffolding 29a Engagement part 29b Holding part 30 Groove receiving part 100 Crane (working machine) 101 Running body 102 Rotating body 103 Boom

Claims

1. A fall prevention device that is arranged around a work machine and used to prevent a worker from falling, a movable hanging member that can lock the attachment worn by the worker; A work platform extending along the movement direction of the hanging member; A fall prevention device comprising:

2. The fall prevention device according to claim 1, The hanging member is provided in plurality, The plurality of suspension members are movable parallel to one another. A fall prevention device characterized by:

3. The fall prevention device according to claim 1, A plurality of auxiliary scaffolds protruding outward from the floor surface of the work platform are provided. A fall prevention device characterized by:

4. The fall prevention device according to claim 3, The auxiliary scaffold is detachably engaged with the work floor. A fall prevention device characterized by:

5. The fall prevention device according to claim 3, The work platform is provided with handrails erected around the periphery thereof, The auxiliary scaffolding can be hooked onto the handrail. A fall prevention device characterized by:

6. The fall prevention device according to claim 1, A leg member is provided to support the work floor, The work platform is movable in the vertical direction relative to the leg members. A fall prevention device characterized by:

7. The fall prevention device according to claim 6, A height adjustment mechanism is provided to adjust the work platform to different height positions of the leg members, The height adjustment mechanism includes a fixing member that can fix the work platform to the leg member, and an operating unit that operates the fixing member to fix or unlock the fixing member below the fixing member. A fall prevention device characterized by:

8. The fall prevention device according to claim 6, A ladder is provided as an elevator to the work platform, The ladder can move up and down in conjunction with the work platform. A fall prevention device characterized by:

9. The fall prevention device according to claim 1, A lifting rope is provided that can lift loads onto the work floor. A fall prevention device characterized by:

10. A method for working at height using a fall prevention device having a work platform, positioning the fall prevention device around the work machine; a step of bringing the work platform closer in height to an upper surface of a work location of the work machine; A procedure in which a worker wearing the harness gets on to the work platform; a procedure in which the worker engages the attachment to a hanging member; a procedure in which the worker moves from the work platform to a work location of the work machine with the attachment fastened to the suspending member; Methods for working at height, including:

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