Safety devices
The safety device for stage equipment addresses the challenge of size and weight by employing a pulley and weight system to prevent falls through a compact mechanism that engages a brake lever at high rotational speeds.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MONIC CORP
- Filing Date
- 2022-05-07
- Publication Date
- 2026-04-22
AI Technical Summary
Existing safety devices for stage equipment are large and heavy, necessitating miniaturization and weight reduction without compromising functionality.
A safety device for stage equipment that utilizes a pulley system with weights and a rotating body to engage a brake lever when excessive rotational speed is detected, preventing the fall of stage equipment by clamping the wire between the pulley and brake lever.
Achieves miniaturization and weight reduction while effectively preventing the fall of stage equipment by using a compact and efficient mechanism.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a safety device for preventing the fall of stage equipment.
Background Art
[0002] A curtain or other stage equipment is suspended by a wire extending from a drum (reel), descends as the wire is paid out from the drum, and ascends as the wire is wound back onto the drum.
[0003] For such stage equipment, the fall of the stage equipment can be prevented by diverting a safety device (for example, see Patent Document 1) for preventing the fall of a cage in an elevator.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, since the safety device for an elevator is a large and heavy object, miniaturization and weight reduction are desired when diverting it to stage equipment.
[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a safety device capable of achieving miniaturization and weight reduction.
Means for Solving the Problems
[0007] The present invention is a safety device for preventing the fall of a stage device that is suspended by a wire extending from a drum, descends as the wire is paid out from the drum, and ascends as the wire is wound back onto the drum, and has a groove around which the wire extending laterally from the drum is hung, and the wire hung in the groove is directed downward Point it at approximately 90 degrees.A pulley that rotates in a first direction in conjunction with the bending and unwinding of the wire from the drum; a weight incorporated in the pulley, positioned in a first position when the pulley is stationary, and moved by centrifugal force from the first position to a second position outside the first position when the pulley rotates in the first direction at a rotational speed exceeding a specified value; a rotating body provided coaxially with the pulley and rotating independently of the pulley; an interlocking mechanism that, when the weight moves to the second position due to the pulley rotating in the first direction at a rotational speed exceeding a specified value, fixes the rotating body to the pulley in conjunction with the weight and rotates the rotating body together with the pulley in the first direction; and a mechanism provided opposite the portion of the groove of the pulley on which the wire is hung, in conjunction with the rotation of the rotating body in the first direction. , toward the direction opposite to the first direction mentioned above The safety device is characterized by comprising: a brake lever that swings to clamp the wire between itself and the pulley; and a link mechanism that interlocks the brake lever with the rotating body and, when the brake lever stops by clamping the wire between itself and the pulley, stops the rotating body, thereby stopping the pulley which is fixed to the rotating body by the interlocking mechanism. [Effects of the Invention]
[0008] The safety device of the present invention makes it possible to achieve miniaturization and weight reduction. [Brief explanation of the drawing]
[0009] [Figure 1] This is a front view of a safety device according to an embodiment of the present invention. [Figure 2] Figure 1 is a rear view of the safety device shown. [Figure 3A] This is a front view of the pulley, showing the weight positioned in the first position. [Figure 3B] This is a front view of the pulley, showing the weight in its second position. [Figure 4A] This is a rear view of the pulley, showing the state where the rotating body is not fixed to the pulley. [Figure 4B]This is a rear view of the pulley, showing the rotating body fixed to the pulley. [Figure 5A] This is a front view of the safety device, showing the pulley in a rotatable state. [Figure 5B] This is a front view of the safety device, showing the brake lever gripping the wire between itself and the pulley, and the pulley in a stopped state. [Modes for carrying out the invention]
[0010] Hereinafter, with reference to the drawings, a safety device 1 according to an embodiment of the present invention will be described in detail.
[0011] First, the configuration of the safety device 1 will be explained using Figures 1 to 5. Figure 1 is a front view of the safety device 1. Figure 2 is a rear view of the safety device 1. Figure 3A is a front view of the pulley 3, showing the state in which weights 4A and 4B are positioned in the first position. Figure 3B is a front view of the pulley 3, showing the state in which weights 4A and 4B have moved to the second position. Figure 4A is a rear view of the pulley 3, showing the state in which the rotating body 7 is not fixed to the pulley 3. Figure 4B is a rear view of the pulley, showing the state in which the rotating body 7 is fixed to the pulley. Figure 5A is a front view of the safety device 1, showing the state in which the pulley 3 is rotatable. Figure 5B is a front view of the safety device 1, showing the state in which the brake lever 10 has a wire sandwiched between it and the pulley 3, and the pulley 3 is stopped. However, in each figure, the illustration of components that are not necessary for the explanation will be omitted as appropriate. In each diagram, arrow L indicates the left, arrow R indicates the right, arrow U indicates the upward direction, and arrow D indicates the downward direction.
[0012] The safety device 1 shown in Figures 1 to 5 is a device that prevents the curtain and other stage equipment (not shown) from falling in the event that the wire W is rapidly unwound from the drum (not shown) due to a malfunction, or that the wire W is cut between the drum (not shown) and the safety device 1. The stage equipment (not shown) is suspended by a wire W extending from the drum (not shown), and descends when the wire W is unwound from the drum (not shown), and rises when the wire W is wound onto the drum. Specifically, the safety device 1 comprises a frame 2, a pulley 3, weights 4A and 4B, an elastic mechanism 5, a connecting arm 6, a rotating body 7, an interlocking mechanism 8, a link mechanism 9, and a brake lever 10.
[0013] Frame 2 is a frame that supports each of the components constituting the safety device 1. Specifically, frame 2 comprises a bottom plate (not shown), a front plate 21, and a rear plate 22. The bottom plate (not shown) is rectangular in shape so as to extend horizontally. The front plate 21 is rectangular in shape so as to extend upward U from the front edge of the bottom plate (not shown). The rear plate 22 is rectangular in shape so as to extend upward U from the rear edge of the bottom plate (not shown) and to be paired with the front plate 21.
[0014] Pulley 3 rotates around a pivot axis A1 that spans the front plate 21 and the rear plate 22 so as to extend in the front-rear direction. This pulley 3 has a groove 3a through which a wire W extending laterally (to the right in the drawing, R) from a drum (not shown) is passed, and the wire W passed through the groove 3a is bent downward D. In addition, pulley 3 rotates in a first direction X in conjunction with the wire W being unwound from the drum (not shown), and rotates in a second direction Y in conjunction with the wire W being wound onto the drum (not shown).
[0015] The weight 4A is incorporated into the pulley 3 and swings about a rotation axis A2 parallel to the rotation axis A1, thereby moving between the first position (see FIG. 3A) and the second position outside the first position (see FIG. 3B). The movement of this weight 4A is restricted by an elastic mechanism 5 provided between the weight 4A and the pulley 3, and it is arranged at the first position (see FIG. 3A) when the pulley 3 is stopped. Further, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, a centrifugal force exceeding the specified value is generated, so that the weight 4A moves from the first position (see FIG. 3A) to the second position outside the first position (see FIG. 3B) against the force of the elastic mechanism 5. Furthermore, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, when the rotational speed at which the pulley 3 rotates drops below the specified value, the weight 4A returns from the second position (see FIG. 3B) to the first position (see FIG. 3A) by the restoring force of the elastic mechanism 5.
[0016] The weight 4B is incorporated into the pulley 3 and swings about a rotation axis A3 parallel to the rotation axis A1, thereby moving between the first position (see FIG. 3A) and the second position outside the first position (see FIG. 3B). This weight 4B is interlocked with the weight 4A by a connecting arm 6. That is, the weight 4B is arranged at the first position (see FIG. 3A) when the pulley 3 is stopped. Further, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, a centrifugal force exceeding the specified value is generated, so that the weight 4B, like the weight 4A, moves from the first position (see FIG. 3A) to the second position outside the first position (see FIG. 3B). Furthermore, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, when the rotational speed at which the pulley 3 rotates drops below the specified value, the weight 4B, like the weight 4A, returns from the second position (see FIG. 3B) to the first position (see FIG. 3A).
[0017] The elastic mechanism 5 generates a restoring force in the direction of extension when it contracts due to an applied external force, and also extends due to the restoring force when the external force is removed. This elastic mechanism 5 is incorporated into the pulley 3 so as to be interposed between the pulley 3 and the weight 4A, and restricts the movement of the weight 4A. Specifically, the elastic mechanism 5 positions the weight 4A in a first position (see Figure 3A) when the pulley 3 is stationary. Furthermore, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, the elastic mechanism 5 contracts due to the centrifugal force exceeding a specified value generated in the weight 4A, thereby allowing the weight 4A to move from the first position (see Figure 3A) to the second position (see Figure 3B). In addition, when the pulley 3 is rotating in the first direction X at a rotational speed exceeding a specified value, the elastic mechanism 5 returns from its contracted state when the rotational speed of the pulley 3 decreases to below a specified value, returning the weight 4A from the second position (see Figure 3B) to the first position (see Figure 3A).
[0018] The connecting arm 6 is incorporated into the pulley 3 so as to be interposed between weights 4A and 4B, and it moves weights 4A and 4B in conjunction. The connecting arm 6 is attached to weight 4A so as to be able to rotate around rotation axis A4 which is parallel to rotation axis A1, and is attached to weight 4B so as to be able to rotate around rotation axis A5 which is parallel to rotation axis A1. As a result, when weight 4A is positioned in the first position (see Figure 3A), the connecting arm 6 positions weight 4B in the first position (see Figure 3A), and when weight 4A moves from the first position (see Figure 3A) to the second position (see Figure 3B), it moves weight 4B to the second position (see Figure 3B). Furthermore, the connecting arm 6 positions weight 4B at the second position (see Figure 3B) when weight 4A is positioned at the second position (see Figure 3B), and moves weight 4B from the second position (see Figure 3B) to the first position (see Figure 3A) when weight 4A moves from the second position (see Figure 3B) to the first position (see Figure 3A).
[0019] The rotating body 7 is provided coaxially with the pulley 3 so as to be disposed behind the pulley 3, and rotates independently of the pulley 3 about the rotation axis A1. This rotating body 7 also serves as a ratchet gear that constitutes the interlocking mechanism 8. Thereby, when a pawl 81 that constitutes the interlocking mechanism 8 meshes with the rotating body 7 (see FIG. 4B), the rotating body 7 rotates in the first direction X in conjunction with the pulley 3 that rotates in the first direction X. Further, when a pawl 81 that constitutes the interlocking mechanism 8 meshes with the rotating body 7 (see FIG. 4B), the rotating body 7 prohibits the pulley 3 from rotating in the first direction X at a rotational speed exceeding the rotating body 7. That is, when a pawl 81 that constitutes the interlocking mechanism 8 meshes with the rotating body 7 (see FIG. 4B) and the rotating body 7 is stopped by the link mechanism 9 (see FIG. 5B), the rotating body 7 prohibits the pulley 3 from rotating in the first direction X.
[0020] The interlocking mechanism 8 is incorporated in the pulley 3 and interlocks the rotating body 7 with the pulley 3 by satisfying a predetermined condition. That is, when the weights 4A and 4B move to the second position (see FIG. 3B) as the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, the interlocking mechanism 8 fixes the rotating body 7 to the pulley 3 in conjunction with the weights 4A and 4B and rotates the rotating body 7 integrally with the pulley 3 in the first direction X (see FIG. 4B). Specifically, the interlocking mechanism 8 includes a rotating body 7 that is a ratchet gear, a pawl 81, a lock piece 82, a coil spring 83, and a torsion spring (not shown).
[0021] The wheel stop 81 moves between a position retracted from the rotating body 7 (see Figure 4A) and a position engaged with the rotating body 7 (see Figure 4B) by oscillating around a rotation axis A6 parallel to the rotation axis A1. The movement of the wheel stop 81 is restricted by a locking piece 82 provided on the pulley 3, and in the initial state, it is positioned in a position retracted from the rotating body 7 (see Figure 4A). Furthermore, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, and the weight 4A moves from the first position (see Figure 3A) to the second position (see Figure 3B), the lock by the locking piece 82 is released, and the wheel stop 81 moves from the position retracted from the rotating body 7 (see Figure 4A) to the position engaged with the rotating body 7 (see Figure 4B) by the restoring force of the coil spring 83.
[0022] The locking piece 82 moves between a position where the wheel chock 81 is locked (see Figure 4A) and a position where it is retracted from the wheel chock 81 (see Figure 4B) by swinging around a rotation axis A7 which is parallel to the rotation axis A1. The movement of the locking piece 82 is restricted by the locking of the wheel chock 81, and in the initial state, it is positioned in the position where the wheel chock 81 is locked (see Figure 4A). Furthermore, when the pulley 3 rotates in the first direction X at a rotation speed exceeding a specified value, and the weight 4A moves from the first position (see Figure 3A) to the second position (see Figure 3B), the locking piece 82 is pushed by the weight 4A, releasing the lock on the wheel chock 81, and the restoring force of the torsion spring (not shown) moves the locking piece 82 from the position where the wheel chock 81 is locked (see Figure 4A) to a position where it is retracted from the wheel chock 81 (see Figure 4B).
[0023] The coil spring 83 generates a restoring force in the direction of contraction when an external force is applied and it is stretched, and it contracts due to the restoring force when the external force is removed. This coil spring 83 is installed so as to be interposed between the pulley 3 and the chock 81, and in its initial state, it is stretched when an external force is applied. Furthermore, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, and the weight 4A moves from the first position (see Figure 3A) to the second position (see Figure 3B), the lock of the chock 81 by the locking piece 82 is released, and the restoring force moves the chock 81 from a position retracted from the rotating body 7 (see Figure 4A) to a position where it engages with the rotating body 7 (see Figure 4B).
[0024] A torsion spring (not shown) generates a restoring force in the opposite direction when an external force is applied and it is twisted, and when the external force is removed, it twists in the opposite direction due to the restoring force. This torsion spring (not shown) is installed so as to be interposed between the pulley 3 and the locking piece 82, and in its initial state, it is twisted when an external force is applied. Furthermore, when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value, and the weight 4A moves from the first position (see Figure 3A) to the second position (see Figure 3B), the lock on the chock 81 by the locking piece 82 is released, and the restoring force moves the locking piece 82 from the position where the chock 81 is locked (see Figure 4A) to a position where it is retracted from the chock 81 (see Figure 4B).
[0025] The link mechanism 9 interlocks the brake lever 10 with the rotating body 7 and stops the pulley 3 when predetermined conditions are met. Specifically, when the brake lever 10 stops with the wire W caught between it and the pulley 3, the link mechanism 9 stops the rotating body 7 which is interlocked with the brake lever 10, thereby stopping the pulley 3 which is fixed to the rotating body 7 by the interlock mechanism 8. Specifically, the link mechanism 9 comprises a first link 91, a second link 92, a third link 93, and a fourth link 94.
[0026] The first link 91 is connected to the rotating body 7 so as to swing about a rotation axis A8 that is parallel to the rotation axis A1. This first link 91 is connected to the second link 92 so as to be perpendicular to the second link 92. When the rotating body 7 rotates in a first direction X, the first link 91 moves to the right R (see Figure 5B). The first link 91 also has a coil spring 91a on the side connected to the second link 92. The coil spring 91a absorbs the shock applied to the link mechanism 9.
[0027] The second link 92 swings around a rotation axis A9 that spans the front plate 21 and the rear plate 22 so as to be parallel to the rotation axis A1 and extending in the front-rear direction. The first link 91 is connected to the second link 92 so as to be perpendicular to it. When the first link 91 moves to the right, the second link 92 swings around the rotation axis A9 in a first direction X (see Figure 5B).
[0028] The third link 93 is fixed to the second link 92 and therefore swings together with the second link 92 around the rotation axis A9. That is, when the second link 92 swings around the rotation axis A9 in the first direction X, the third link 93 swings together with the second link 92 around the rotation axis A9 in the first direction X (see Figure 5B). In addition, the fourth link 94 is connected to the third link 93 so as to swing around a rotation axis A10 which is parallel to the rotation axis A1.
[0029] The fourth link 94 is connected to the third link 93 so as to pivot about a rotation axis A10 that is parallel to the rotation axis A1. The brake lever 10 is connected to this fourth link 94 so as to pivot about a rotation axis A11 that is parallel to the rotation axis A1. When the third link 93 pivots in a first direction X about the rotation axis A9, the fourth link 94 moves to the left L (see Figure 5B).
[0030] The brake lever 10 is positioned opposite the portion of the groove 3a of the pulley 3 on which the wire W is attached, and swings in conjunction with the rotation of the rotating body 7 in a first direction X, thereby clamping the wire W between itself and the pulley 3. Specifically, the brake lever 10 swings around a rotation axis A12 that is stretched across the front plate 21 and the rear plate 22 so as to be parallel to the rotation axis A1 and extending in the front-rear direction. This brake lever 10 is connected to a fourth link 94 so as to swing around a rotation axis A11 that is parallel to the rotation axis A1. When the fourth link 94 moves to the left L, the brake lever 10 swings around the rotation axis A12 in a second direction Y, thereby clamping the wire W between itself and the pulley 3.
[0031] Next, using Figures 1 and 2, the operation of safety device 1 during the raising and lowering of the stage equipment (not shown) will be explained.
[0032] As shown in Figures 1 and 2, the pulley 3 rotates in a first direction X at a rotational speed below a specified value in conjunction with the wire W being unwound from the drum (not shown), or rotates in a second direction Y in conjunction with the wire W being wound onto the drum (not shown). In these cases, the weight 4A is maintained in a first position (see Figure 3A) by the elastic mechanism 5. The weight 4B is maintained in a first position (see Figure 3A) by the connecting arm 6. The interlocking mechanism 8 is maintained in a position where the stopper 81 is retracted from the rotating body 7 (see Figure 4A). The rotating body 7 does not rotate because it is not interlocked with the pulley 3. The brake lever 10 does not swing because the rotating body 7 does not rotate, and does not pinch the wire W between it and the pulley 3. Thus, the safety device 1 does not function when the stage equipment (not shown) is raised or lowered.
[0033] Next, using Figures 1 to 5, we will explain the operation of safety device 1, which prevents stage equipment (not shown) from falling.
[0034] As shown in Figures 1 to 5, if the wire W is rapidly unwound from the drum (not shown) due to a malfunction, or if the wire W is cut between the drum (not shown) and the safety device 1, the pulley 3 rotates in the first direction X at a rotational speed exceeding the specified value. In this case, the weight 4A is moved from the first position (see Figure 3A) to a second position (see Figure 3B) outside the first position, against the force of the elastic mechanism 5, due to the centrifugal force exceeding the specified value. The weight 4B, like the weight 4A, is moved from the first position (see Figure 3A) to a second position (see Figure 3B) outside the first position, due to the centrifugal force exceeding the specified value. The locking piece 82 is pushed by the weight 4A and moves from the position where it locks the stopper 81 (see Figure 4A) to the position where it is retracted from the stopper 81 (see Figure 4B). When the lock on the lock piece 82 is released, the chock 81 moves from a position retracted from the rotating body 7 (see Figure 4A) to a position where it engages with the rotating body 7 (see Figure 4B) due to the restoring force of the coil spring 83. The rotating body 7 rotates in the first direction X in conjunction with the pulley 3 which rotates in the first direction X (see Figure 4B). The brake lever 10 swings in conjunction with the rotating body 7 which rotates in the first direction X, thereby sandwiching the wire W between itself and the pulley 3 (see Figure 5B).
[0035] Thus, the safety device 1 is suspended by a wire W extending from a drum, and prevents the fall of a stage device that descends when the wire W is unwound from the drum and rises when the wire W is wound onto the drum. It has a groove 3a through which the wire W extending laterally from the drum is hooked, and a pulley 3 that bends the wire W hooked in the groove 3a downward and rotates in a first direction X in conjunction with the unwound of the wire W from the drum; weights 4A, 4B incorporated into the pulley 3 and positioned in a first position when the pulley 3 is stopped, and which move from the first position to a second position outside the first position by centrifugal force when the pulley 3 rotates in the first direction X at a rotational speed exceeding a specified value; and a rotating body 7 provided coaxially with the pulley 3 and rotating independently of the pulley 3. The system includes: an interlocking mechanism 8 that, when the pulley 3 rotates in a first direction X at a rotational speed exceeding a specified value, causing the weights 4A and 4B to move to a second position, fixes the rotating body 7 to the pulley 3 in conjunction with the weights 4A and 4B, and rotates the rotating body 7 together with the pulley 3 in the first direction X; a brake lever 10 provided opposite the portion of the groove 3a of the pulley 3 on which the wire W is attached, and swings in conjunction with the rotation of the rotating body 7 in the first direction X to clamp the wire W between itself and the pulley 3; and a link mechanism 9 that interlocks the brake lever 10 with the rotating body 7, and when the brake lever 10 stops with the wire W clamped between itself and the pulley 3, stops the rotating body 7, thereby stopping the pulley 3 which is fixed to the rotating body 7 by the interlocking mechanism 8.
[0036] Such a safety device 1 makes it possible to achieve a smaller and lighter design.
[0037] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from its spirit and technical concept. That is, the position, size, length, quantity, shape, material, and order of operation of each component can be changed as appropriate. [Explanation of Symbols]
[0038] 1 Safety equipment 2 frames 21 Front panel 22 Rear plate 3 Pulleys 3a groove 4A,4B weight 5. Elastic Mechanism 6 connecting arms 7. Solids of revolution 8. Interlocking mechanism 81. Brakes 82 Rock Pieces 83 Coil spring 9 Link mechanism 91 First Link 91 Coil spring 92 Second Link 93 Third Link 94. 4th Link 10 Brake levers A1~A12 Rotation axis W wire X First direction Y Second direction L left R Right side U upward D Downward
Claims
[Claim 1] A safety device for preventing the fall of a stage device that is suspended by a wire extending from a drum, which descends when the wire is unwound from the drum and rises when the wire is wound onto the drum, A pulley having a groove through which the wire extending laterally from the drum is passed, bending the wire passed in the groove downward by approximately 90 degrees, and rotating in a first direction in conjunction with the wire being unwound from the drum, A weight incorporated into the pulley, positioned in a first position when the pulley is stationary, and moved by centrifugal force from the first position to a second position outside the first position when the pulley rotates in the first direction at a rotational speed exceeding a specified value, A rotating body provided coaxially with the pulley and rotating independently of the pulley, When the pulley rotates in the first direction at a rotational speed exceeding a specified value, causing the weight to move to the second position, an interlocking mechanism is provided to fix the rotating body to the pulley in conjunction with the weight, and to rotate the rotating body together with the pulley in the first direction. A brake lever is provided so as to be opposite to the portion of the pulley through which the wire is threaded in the groove of the pulley, and in conjunction with the rotation of the rotating body in the first direction, it swings in the direction opposite to the first direction, thereby clamping the wire between itself and the pulley. The system is characterized by comprising: a link mechanism that interlocks the brake lever with the rotating body, and stops the rotating body when the brake lever stops due to the wire being caught between it and the pulley, thereby stopping the pulley which is fixed to the rotating body by the interlocking mechanism. Safety equipment.
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