Wire slack detection device

Abstract

To provide a wire slack detection device that can reliably detect wire slack with excellent detection accuracy at the time of descent of a baton pipe.SOLUTION: A wire slack detection device 1 includes: a winding drum 13; a wire W wound around the winding drum 13; a suspension pulley 11 for guiding the wire W in a vertical direction; and a baton pipe 20 fixed to an end of the wire W. The wire slack detection device 1 is configured to include: a detection member 2 disposed in the vicinity of the suspension pulley 11, including biasing means exerting pressing force to the wire W while coming into contact with the wire, and having a movable range parallel to a pressing direction; a guide member 3 disposed in the vicinity of the detection member 2 to guide the wire coming into contact with the detection member 2 in the opposite direction to a biasing direction and guiding the wire toward the winding drum at the same time; and a switch element SW for detecting displacement of the detection member 2 and delivering an on / off signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wire slack detection device for a lifting baton used in studios, stages, conference rooms, halls, classrooms, etc. [Background technology]

[0002] An elevator known as a lifting baton is used to raise and lower lighting equipment, screens, signs, curtains, etc. used in studios, stages, conference rooms, halls, classrooms, etc.

[0003] However, when a lifting baton descends, one of the devices hanging from the baton may come into contact with an obstacle. If this condition is left unaddressed and the baton continues to descend, the tension in the wire suspending the baton pipe will be lost, causing the wire to be unloaded.

[0004] This causes the roller around which the wire is wound to spin freely, causing the wound wire to swell and create a condition known as "disarray winding," which is similar to backlash in fishing reels.

[0005] In this state, normal operation becomes difficult, and the lifting mechanism may be damaged or require maintenance.

[0006] Patent Document 1 discloses a technique in which, when the baton is lowered, a slack detection unit detects slack and stops the operation of the motor unit of the lowering device.

[0007] As a slack detection mechanism in such a slack detection section, for example, the structure shown in FIG. 4 is known.

[0008] The detection mechanism 50 shown in the figure has a detection switch SW' disposed near a suspension pulley 51 for suspending the baton pipe, and is positioned so that the tip of an actuator ACT' of the detection switch SW' comes into contact with a hanging wire W.

[0009] At this time, the actuator is pressed to turn on the detection switch SW' when the hanging wire W is in a taut state, and adjusted to turn off when the wire W is relaxed. This makes it possible to detect slack in the wire W when the baton is lowered.

[0010] However, such a conventional detection mechanism 50 has poor detection accuracy and may malfunction if the suspended baton pipe sways or vibrates. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-101947 Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been made to address such problems, and aims to provide a wire slack detection device that can accurately and reliably detect slack in the wire caused by obstacles, etc. when the baton pipe is lowered. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention has the following features.

[0014] (1) A wire slack detector of the present invention is a wire slack detector having a winding drum, a wire wound around the winding drum, a suspension pulley that guides the wire in a vertical direction, and a baton pipe fixed to an end of the wire, a detection member disposed near the suspension pulley, having a biasing means for contacting the wire and applying a pressing force thereto, and having a movable range within which the detection member can be moved by the biasing force of the biasing means; a guide member that is disposed near the detection member and guides the wire in contact with the detection member in a direction opposite to the biasing direction of the biasing means and toward the winding drum; a switch element that detects the displacement of the detection member and sends an on / off signal; (hereinafter referred to as the first wire slack detection device of the present invention).

[0015] According to the first wire slack detection device of the present invention, the detection member contacts the wire and applies a pressing force, and the displacement of this detection member is detected by a switch element, so that wire slack can be detected accurately and reliably, and there is little malfunction.

[0016] (2) In the wire slack detector of the first invention, the detector and guide member are a detector pulley and a guide pulley (hereinafter referred to as a wire slack detector of the second invention).

[0017] According to the second wire slack detection device of the present invention, the detection member and guide section can be constructed using easily available pulleys, and since the wire moves smoothly, the detection member can be displaced smoothly, making it possible to detect wire slack more accurately and reliably.

[0018] (3) In the wire slack detector of the first or second invention, the biasing means is gravity exerted from the detector (hereinafter referred to as the wire slack detector of the third invention).

[0019] According to the wire slack detector of the third aspect of the present invention, gravity is used as the biasing means, so the structure is simple, there are few malfunctions, and a reliable slack detection function can be ensured for a long period of time. [Effects of the Invention]

[0020] The wire slack detection device according to the present invention is configured as described above, and therefore is capable of detecting slack in the suspension wire with high accuracy and reliability. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a front view showing an embodiment of the lifting baton device of the present invention; [Figure 2A] FIG. 1 is a front view showing the configuration of a wire slack detection device according to the present invention. [Figure 2B] FIG. 2 is a side view showing the configuration of the wire slack detection device of the present invention. [Figure 3] FIG. 2 is a front view showing the wire slack detection device of the present invention in an inclined position. [Figure 4] FIG. 10 is a plan view showing a detection switch that is a conventional slack detection device. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, a wire slack detection device according to an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be described with reference to the accompanying Figs.

[0023] FIG. 1 is a front view showing the overall configuration of a lifting baton device 10 according to this embodiment.

[0024] The lifting baton device 10 of this embodiment is placed on the ceiling of a studio, stage, conference room, hall, classroom, etc. A pair of suspension pulleys 11 for suspending the baton pipes 20 are placed near both ends of the lifting baton device 10.

[0025] 2A and 2B are a front view and a left side view showing the overall configuration of slack detector 1 of the present invention.

[0026] The slack detection device 1 of this embodiment has a detection pulley 2 as a detection member arranged near the suspension pulley 11, and a guide pulley 3 as a guide member arranged next to the detection pulley 2 on a different side from the suspension pulley 11.

[0027] The detection pulleys 2 are preferably arranged in an inverted figure eight shape near the suspension pulley 11. However, considering the possibility of retrofitting the detection pulleys 2 to an already fixed suspension pulley 11, it is difficult to place them too close.

[0028] The detection pulley 2 is arranged on the winding drum 13 side of the wire W stretched over the suspension pulley 11, and has the function of applying a biasing force to the wire W extending from the suspension pulley 11, forcibly bending it against the tension.

[0029] Furthermore, the detection pulley 2 has a movable range in which it can move in a direction parallel to the biasing force, and therefore can move within this movable range to a position where the biasing force and the tension of the wire W are in balance.

[0030] Therefore, when the baton pipe or the equipment attached to it comes into contact with an obstacle and the tension in the wire W is released, it moves to a position where it can be moved only by the biasing force, that is, in this embodiment, to the bottom dead center below.

[0031] The movable range of the detection pulley 2 is set by a pulley shaft fixing hole 6, which is an elongated hole formed in the case 4. The pulley shaft of the detection pulley 2 is attached to this pulley shaft fixing hole 6 so as to be able to slide freely.

[0032] The length of the pulley shaft fixing hole 6 is determined in accordance with the movement distance of the detection pulley 2. Specifically, although it differs depending on the size of the detection pulley 2 and the thickness of the wire W, it is recommended to set it in the range of 15 to 40 mm when using a wire W with a diameter of 2 to 3 mm.

[0033] Specifically, thrust washers are placed on both outsides of the case 4 in which the detection pulley 2 is placed, and the detection pulley 2 is fixed through these with a screw member 9 for fixing the pulley shaft. At this time, a double nut or the like is used to prevent friction caused by the tightening force between the detection pulley 2 and the case 4.

[0034] A detection flange 2a serving as a detection protrusion is formed at a position protruding in the axial direction on the detection pulley 2. In this embodiment, the detection flange 2a is formed as a flange with a diameter approximately 30 to 50% smaller than the outer diameter of the detection pulley 2. The detection flange 2a, together with a detection element SW described later, has the function of detecting positional fluctuations, i.e., displacement, of the detection pulley 2.

[0035] The closer the distance between the suspension pulley 11 and the detection pulley 2, the higher the detection sensitivity. However, taking into consideration ease of installation, it is advisable to set the minimum distance between the outer diameters of the suspension pulley 11 and the detection pulley 2 to approximately 15 to 40% of the outer diameter of the detection pulley 2.

[0036] Furthermore, the wire stretched between the suspension pulley 11 and the detection pulley 2 forms an inverted S-shape, and the inclination θ1 of the acute angle side of the straight portion of the wire W between the suspension pulley 11 and the detection pulley 2 relative to the vertical line is preferably as acute as possible for the same reasons as above, and may be set, for example, in the range of 30 to 60°, preferably 40 to 50°.

[0037] The size of the detection pulley 2 varies depending on the scale of the lifting baton device 10, but may be set to be approximately the same as or smaller than the suspension pulley 11. Specifically, for a small to medium-sized lifting baton device, the diameter is about 50 to 180 mm.

[0038] The detection pulley 2 is equipped with a biasing means. While it is conceivable to use an elastic member such as a spring as the biasing means, in this embodiment, gravity acting from the mass of the detection pulley 2 is utilized. In other words, the weight of the detection pulley 2 bends the wire W. Therefore, it is desirable to set the movable range of the detection pulley 2 to an area along the vertical direction.

[0039] The mass of the detection pulley 2 should be set to a mass that can sufficiently bend the wire W used and can move to the opposite side of the position to which the wire W moves only by the spring force of the pulley shaft fixing hole 6, that is, to the top dead center in this embodiment, when the wire W becomes tensed due to the mass of the member it is pulling.

[0040] Specifically, if the diameter of the wire W used is 2 to 3 mm, the mass may be set in the range of 0.3 kg to 10 kg. The means for adding mass is preferably the weight of the detection pulley 2 itself, but the mass may also be adjusted by attaching a weight as needed.

[0041] Although resin can be used as the material for the detection pulley 2, metal materials such as iron, SUS, brass, and aluminum are preferred, and cast iron is preferred from the standpoint of ease of manufacture and cost.

[0042] For smooth operation, it is preferable that the detection pulley 2 is integrally mounted with a bearing such as a ball bearing. In this case, it is advisable to fix only the inner ring portion of the bearing when fixing.

[0043] A switch element SW is disposed near the detection pulley 2. As described above, this switch element SW detects the displacement of the detection pulley 2. For this reason, the switch element SW is disposed at a position where the displacement of the detection pulley 2 can be detected.

[0044] In this embodiment, the detection element is a limit switch.

[0045] The detection element SW has a main body equipped with a microswitch and an actuator ACT that assists the detection operation. In this embodiment, the actuator ACT is a long, thin plate-like body with one end rotatably fixed to the detection element SW and the other end extending outward from the detection element SW, and is in contact with an operating piece protruding from the detection element SW near the one end. The actuator ACT is elastic and can bend to a certain extent, allowing for a wide operating range.

[0046] When the other end of the actuator ACT is pressed down, the operating piece is pressed down using the principle of leverage, causing the detection element SW to operate. This allows the detection element SW to operate with even a slight force.

[0047] The detection element SW can detect the displacement of the detection pulley 2 by contacting the actuator ACT with the main body of the detection pulley 2, but since this may interfere with the operation of the detection pulley 2 or cause malfunction, in this embodiment the displacement of the detection pulley 2 is detected by contacting the actuator ACT with a detection flange 2a, which serves as a detection protrusion formed on the detection pulley 2.

[0048] That is, as shown in FIG. 2, when the wire W is in a tensioned state, the detection pulley 2 is positioned above the pulley shaft fixing hole 6, and in this state the detection flange 2a and the actuator ACT are separated, and the operating piece of the detection element SW is not pressed down, so the detection element SW is set to not operate (OFF).

[0049] On the other hand, when the wire W loosens and the detection pulley 2 moves downward in the pulley shaft fixing hole 6, the detection flange 2a also presses down the actuator ACT by the same stroke. Then, midway through the downward movement, the operating piece of the detection element SW is pressed down via the actuator ACT, and the detection element SW is activated and turned ON. As a result, the control device 16, which will be described later, detects the loosening of the wire W and stops the motor 14.

[0050] A guide pulley 3 is arranged adjacent to the detection pulley 2. The guide pulley 3 has a function of returning the wire W bent by the detection pulley 2 to its normal position and guiding it toward the winding drum 13.

[0051] Furthermore, by supporting the wire W between the suspension pulley 11 and the guide pulley 3 with the detection pulley 2 sandwiched therebetween, the wire is bent into a U-shape, thereby improving the detection accuracy of the detection pulley 2.

[0052] The guide pulley 3 may be the same as or different from the detection pulley 2. For example, it may be lighter than the detection pulley 2. The size of the guide pulley 3 may be the same as that of the detection pulley 2, or may be set to a size required depending on the required capacity.

[0053] The closer the distance between the detection pulley 2 and the guide pulley 3, the higher the detection sensitivity. However, taking into consideration ease of installation and the flexibility of the wire W used, it is advisable to set the minimum distance between the outer diameters of the detection pulley 2 and the guide pulley 3 to approximately 5 to 20% of the outer diameter of the detection pulley 2.

[0054] Furthermore, the wire stretched between the detection pulley 2 and the guide pulley 3 forms an inverted S-shape, and the inclination θ2 of the acute angle of the straight portion of the wire W between the detection pulley 2 and the guide pulley 3 relative to the vertical line is preferably as acute as possible for the same reasons as above, and may be set, for example, in the range of 20 to 40°, preferably 25 to 35°.

[0055] Commercially available products can be purchased and used for the detection pulley 2 and guide pulley 3. The detection pulley 2, guide pulley 3, and switch element SW are integrally attached to a case 4.

[0056] At the center of the lifting baton device 10, there is a winding drum 13 that is placed inside the housing 12 and winds up the wire W, a motor 14 that rotates the winding drum 13 to wind up and feed out the wire W, a limiter 15 that stops the operation of the winding drum 13 at the top dead center and bottom dead center of the baton pipe 20, and a control device 16 that controls the operation of the lifting baton device 10.

[0057] The suspension pulley 11 has the function of changing the extension direction of the hanging wire W connected to the baton pipe 20 and guiding it to the center of the lifting baton device 10.

[0058] In addition, the load of the substrate attached to the baton pipe 20 becomes a load that applies tension to the wire, but by using the suspension pulley 11, a portion of the load can be supported on a structure such as the ceiling via the suspension pulley 11, thereby alleviating the tension and smoothly guiding the movement associated with winding and unwinding the wire W.

[0059] The winding drum 13 is a cylindrical object, and stores the wire W by winding the wire W that suspends the baton pipe 20 around its outer periphery. In addition, the rotation of the winding drum 13 allows the wire W to be wound up and let out, thereby causing the baton pipe 20 to rise and fall.

[0060] The winding drum 13 is preferably disposed in the center of the lifting baton device 10. By disposing it in the center, when the wire W connected to the baton pipe 20 via the suspension pulleys 11 near both ends of the lifting baton device 10 is wound from both ends of the winding drum 13, the same amount of wire W can be wound toward the center of the winding drum 13.

[0061] Also, a guide member is provided to ensure that the winding drum 13 is neatly aligned and wound up, thereby preventing double winding and the like.

[0062] The winding drum 13 is connected to and driven by a motor 14. A normal AC motor or the like can be used as the motor 14, but a reversible motor is preferable in order to rotate forward and backward. If necessary, a brake or a reducer may be provided. If necessary, a DC motor, servo motor, or pulse motor may also be used.

[0063] The wire W is used to suspend the baton pipe 20. For this reason, it is desirable that the wire W has a predetermined strength and flexibility that allows it to be bent and wound up.

[0064] Specifically, steel (iron) and SUS stranded wires are preferred, and manila ropes can also be used. Other materials that can be used as needed include nylon single wires, para-aramid fiber yarns, and polyethylene yarns.

[0065] The diameter of the wire W may be 1 mm to 8 mm, preferably 2 mm to 6 mm, depending on the application, in the case of a stranded steel (iron) wire.

[0066] The limiter 15 can set multiple stop positions for the baton pipe 20, such as the top dead center and the bottom dead center. Normally, for safety reasons, the limiter 15 sets the stop position for the baton pipe 20 based on the rotation speed of the winding drum 13, but this function may be given to the control device 16, which will be described later.

[0067] The control device 16 receives input from an operation switch such as a remote control (not shown) and controls the start, stop, forward rotation, reverse rotation, etc. of the motor 14. It is also possible to stop the baton pipe 20 using an external sensor, etc. Furthermore, if necessary, the operation of the baton pipe may be controlled by connecting to an external control device.

[0068] The control device 16 can be configured by combining relays as long as it performs a simple operation. It can also be configured by combining logic elements and switching elements such as transistors, and a processor can be used if necessary.

[0069] The baton pipe 20 is suspended by a wire W and is used to attach equipment, screens, signs, curtains, and other devices and props necessary for production in studios, stages, conference rooms, halls, classrooms, etc., and move them up and down.

[0070] The size of the baton pipe 20 is, for example, about 20 mm to 60 mm in diameter, and the length can be set as needed. The material is preferably a metal having a certain degree of strength, such as iron or SUS.

[0071] The functions and effects of this embodiment will be described below. [Actions and Effects]

[0072] According to the wire slack detector 1 of this embodiment, the detection pulley 2 contacts the wire W and applies a pressing force, while the displacement of the detection pulley 2 is detected by the switch element SW, so that the slack of the wire W can be detected accurately and reliably with few malfunctions. In addition, the device can be constructed inexpensively using easily available pulleys, and the pulleys smooth the movement of the wire W, allowing the detection pulley 2 to be smoothly displaced, allowing the slack of the wire W to be detected more accurately and reliably.

[0073] Furthermore, since the detection pulley 2 and the guide pulley 3 are arranged close to each other, the accuracy with which the detection pulley 2 detects slack in the wire can be improved.

[0074] Furthermore, since the detection pulley 2 and the suspension pulley 11 are disposed close to each other, the accuracy with which the detection pulley 2 detects slack in the wire can be further improved.

[0075] Furthermore, since the pressing force is applied by the weight of the detection pulley 2 itself, no parts for applying the pressing force are required, the structure is simple, and there are few malfunctions.

[0076] The displacement of the detection pulley 2 is detected by a switch element SW equipped with an actuator ACT, which has a relatively simple configuration and can be manufactured inexpensively. Moreover, the elasticity of the actuator ACT provides a certain degree of range in its operating range, allowing for reliable detection and reducing the risk of malfunction.

[0077] [Variations] The wire slack detection device 1 of the present invention is not limited to the above embodiment, and may be configured as follows.

[0078] In this embodiment, an example has been described in which pulleys are used as the detection member and guide member, but the present invention is not limited to this. For example, the detection member and guide member may be formed by combining a cylindrical member with a smooth surface or a member with a U-shaped cross section.

[0079] In this embodiment, the detection pulley 2 is provided with a detection flange 2a as a detection protrusion to detect the displacement of the detection pulley 2, but the present invention is not limited to this, and the displacement of the detection pulley 2 itself may be detected, or the detection protrusion may be cylindrical rather than flange-shaped. Also, the outer periphery of the pulley side surface may extend radially.

[0080] In this embodiment, the weight of the detection pulley 2, which is the detection member, is used as the biasing means, but the present invention is not limited to this, and biasing may be performed by an elastic member such as a leaf spring or a coil spring.

[0081] In this embodiment, an example has been shown and described in which a switch element SW is used as an element for detecting the displacement of the detection pulley 2, but the present invention is not limited to this, and non-contact detection elements such as a photoelectric switch, a photocoupler, or a magnetic proximity switch may also be used.

[0082] In this embodiment, an example has been shown and described in which the pulley shaft fixing hole 6 is formed as a linear elongated hole, but the present invention is not limited to this, and the hole may be inclined or curved to some extent as long as the detection pulley 2 can be moved by the biasing force. [Explanation of symbols]

[0083] 1. Slack detection device 2. Detection pulley (detection member) 3 Guide pulley (guide member) 6 Pulley shaft fixing hole 8 washers 9 Screw parts 10 Lifting Baton 11 Suspension pulley 12 cases 13 Winding drum 20 Baton Pipe W Wire SW switch element

Claims

1. A wire slack detection device having a winding drum, a wire wound around the winding drum, a suspension pulley that guides the wire in a vertical direction, and a baton pipe fixed to an end of the wire, a detection member disposed near the suspension pulley, having a biasing means for contacting the wire and applying a pressing force thereto, and having a movable range within which the detection member can be moved by the biasing force of the biasing means; a guide member that is disposed near the detection member and guides the wire in contact with the detection member in a direction opposite to the biasing direction of the biasing means and toward the winding drum; a switch element that detects the displacement of the detection member and sends an on / off signal; A wire slack detection device comprising:

2. 2. The wire slack detector according to claim 1, wherein said detecting member and said guide member are a detecting pulley and a guide pulley.

3. 3. A wire slack detector according to claim 1, wherein said biasing means is gravity acting from the detector.

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