JP2012223865A - Screw fall prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw fall prevention device capable of surely collecting a screw, loosened by a screwdriver tool, only by a one hand operation without dropping.SOLUTION: The screw fall prevention device includes: an inner insulated cylinder 10 that has a catching part 122 capable of holding the screw 83 loosened by the screwdriver tool 90 and a first pressing surface 122a capable of contacting a connecting terminal 82 side of a terminal base 20; an outer insulated cylinder 20 that has a holding cylinder part 21 covering the catching part 122 and a second pressing surface 21c capable of contacting the connecting terminal 82 of the terminal base 80; and an energizing means 40 that energizes the outer insulated cylinder 20 in an axial direction, so that the second pressing surface 21c projects from the first pressing surface 122a in the axial direction, and energizes the inner insulated cylinder 10 in a direction to retreat from the outer insulated cylinder 20 in a condition that the first pressing surface 122a and the second pressing surface 21c are in contact with the connecting terminal 82 side of the terminal base 80.

Description

  The present invention relates to a screw drop prevention tool that is used by being mounted on a screwdriver tool, and more particularly to a screw drop prevention tool that can reliably prevent a screw from falling when the screw is loosened by a screwdriver tool.

Electrical equipment such as a control panel is provided with a terminal block for relay for connecting electric wires. The ends of the electric wires are fixed to the connection terminals of the terminal block by tightening screws. When removing the wiring from the connection terminal of the terminal block during energization, it is necessary to loosen the screw by holding the wiring with one hand and rotating the tool with the other hand. In a control panel or the like, dropping a screw that has been loosened by a screwdriver tool may cause the dropped screw to come into contact with other parts that are energized, leading to equipment failure. Therefore, it is necessary to surely prevent the loosened screws from dropping in the electric devices that are energized.

  Conventionally, a technique for preventing a loosened screw from falling is known (see Patent Documents 1 and 2). In the techniques of Patent Documents 1 and 2, a cylinder holding a loosened screw is provided at the tip of a screwdriver tool so as to be movable in the axial direction, and the cylinder is urged in the axial direction via an elastic member. ing. There is also known a technique of tightening a screw while holding the screw head (see Patent Documents 3 and 4). In the techniques of Patent Documents 3 and 4, when a screw is fastened to a heel portion of a high heel, the screw is prevented from falling by gripping the head of the screw.

Japanese Utility Model Publication No. 50-29598 Japanese Utility Model Publication No. 62-150070 Utility Model Registration No. 3131223 JP 2010-179432 A

  However, in electrical equipment that is energized, when removing it from the terminal block using a screwdriver, hold the wiring with one hand and loosen the screw by rotating the screwdriver with the other hand. After removing it from the base, the screw is pulled out from the terminal of the wiring. At this time, the screw may be dropped. Also, because there is a risk of electric shock, the screws cannot be held directly by hand, and rubber gloves will be used. However, if rubber gloves are used, the feeling of hands will become dull and the screws will fall. It cannot be reliably prevented. Conventionally, when a screw is loosened, the lower part of the electrical equipment is insulated and cured with an insulating sheet or the like in consideration of the case where the screw is dropped, which requires time and effort.

  In addition, for example, in power facilities of power supply companies, many screws made of non-ferrous metals such as brass are used as screws that can be loosened by a screwdriver to ensure high conductivity. Even if the part is magnetized, it is difficult to reliably prevent the screw from falling when the screw is loosened.

  As in the above-mentioned Patent Documents 1 and 2, in the technique in which the cylinder for holding the screw is provided at the tip of the screwdriver tool, the loosened screw enters the cylinder, but the cylinder is moved when the screwdriver tool is moved. There is a problem that it may fall out of the case and lack of reliability. In addition, the above-mentioned Patent Documents 3 and 4 are techniques related to screw tightening, and cannot securely hold a loosened screw. Furthermore, in Patent Documents 3 and 4, in order to cause the device to hold the screw, it is necessary to hold the screw with one hand and push down the operating portion of the tightening device with the other hand. There is a problem that can not be.

  Therefore, for the work of loosening the screw in the electric device that is energized, it is required to reliably collect the screw loosened by the screwdriver tool without dropping it with only one hand operation.

  Then, an object of this invention is to provide the screw fall prevention tool which can collect | recover reliably, without dropping the screw loosened with the screwdriver tool only by one-hand operation.

  In order to achieve the above object, the invention described in claim 1 is composed of a cylindrical member having an electrical insulation property into which a screwdriver tool can be inserted, and is elastically deformable in one of the axial directions in the radial direction, and the screwdriver. A catch portion capable of gripping the head of a screw loosened by a tool is formed, and the tip end surface in the axial direction of the catch portion is formed on a first pressing surface that can come into contact with a screwing member side to which the screw is screwed. An inner insulating cylinder, and a cylindrical member having an electrical insulating property capable of moving forward and backward in the axial direction with respect to the inner insulating cylinder, and having a holding cylinder portion covering the outer periphery of the catch portion on one side in the axial direction An outer insulating cylinder formed on a second pressing surface in which an axial front end surface of the holding cylinder part can come into contact with the screwing member side; and an outer periphery of the inner insulating cylinder, and the second pressing The outer edge in a direction in which the surface projects axially from the first pressing surface. In a state where the tube is urged in the axial direction and the first pressing surface and the second pressing surface are in contact with the screwing member side, the inner insulating tube is moved backward with respect to the outer insulating tube. Urging means for urging in the direction to be moved, and the catch portion of the urging means from a state in which the first pressing surface and the second pressing surface are in contact with the screwing member side. When the inner insulating cylinder is retreated by a predetermined distance in the axial direction with respect to the outer insulating cylinder by an urging force, the inner insulating cylinder is displaced radially inward by contact with the reduced diameter portion formed in the outer insulating cylinder. It is a screw fall prevention tool.

  According to the present invention, the screw is loosened by the screwdriver tool in a state where the first pressing surface and the second pressing surface are pressed against the screwing member to which the screw is screwed. Then, after releasing the screw, the biasing force of the biasing means is released by releasing the axial pressing by the screwdriver tool in a state where the first pressing surface and the second pressing surface are pressed against the screwing member side. As a result, the inner insulating cylinder moves backward with respect to the outer insulating cylinder, and the loosened screw head is gripped by the catch portion by contact with the reduced diameter portion formed in the outer insulating cylinder.

  According to a second aspect of the present invention, in the screw fall prevention device according to the first aspect, the at least one of the inner insulating cylinder and the outer insulating cylinder is provided with the pressing force against the first pressing surface by the urging means. It is characterized in that a length adjusting section for adjusting the protruding length in the axial direction of the second pressing surface is provided.

  According to a third aspect of the present invention, in the screw drop prevention device according to the first or second aspect, the urging means is composed of a metal compression coil spring, and the compression coil spring is formed by the inner insulation. It is characterized by being covered with an electrically insulating cover provided outside the cylinder.

  According to a fourth aspect of the present invention, in the screw drop prevention device according to any one of the first to third aspects, the inner insulating tube and the outer insulating tube are made of a transparent or translucent resin. It is characterized by that.

  According to the first aspect of the present invention, in the state where the second pressing surface of the outer insulating cylinder is in contact with the screwing member, the head portion of the screw can be gripped by the catch portion by the retreat of the inner insulating cylinder. As a result, the screw loosened by the screwdriver can be reliably recovered with only one hand operation, and curing with an insulating sheet is not required. In addition, since the operation can be performed only with one hand, when loosening the screw, the wiring connected to the screwing member side through the screw can be held with the other hand, so that the work can be safely performed. be able to. Furthermore, since the head portion of the screw is gripped by the catch portion, even a screw made of a non-ferrous metal that cannot be attracted by the magnet can be reliably recovered without dropping.

  According to the second aspect of the present invention, the protruding length in the axial direction of the second pressing surface with respect to the first pressing surface by the urging means is adjusted to at least one of the inner insulating tube and the outer insulating tube. Since the length adjusting portion is provided, the protruding length of the outer insulating cylinder can be adjusted corresponding to the length of the screw, and various screws having different lengths can be gripped.

  According to the third aspect of the present invention, the metal compression coil spring as the biasing means is covered by the electric insulating cover provided outside the inner insulating cylinder, so that the safety against electric shock is improved. Can do.

  According to the invention described in claim 4, since the inner insulating cylinder and the outer insulating cylinder are made of transparent or translucent resin, the state of the screwdriver and the screw to be loosened can be confirmed from the outside. , Can increase the work efficiency.

It is sectional drawing at the time of the loosening operation | work start of the screw using the screw fall prevention tool concerning Embodiment 1 of this invention. It is sectional drawing which shows the holding | grip state of the screw by the screw fall prevention tool of FIG. It is a perspective view of the catch part of the inner cylinder of the screw fall prevention tool of FIG. It is an expanded sectional view of the protrusion length adjustment part of the screw fall prevention tool of FIG. It is sectional drawing which shows each process of the loosening operation | work of a screw using the screw fall prevention tool of FIG. It is sectional drawing of the screw fall prevention tool concerning Embodiment 2 of this invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
1 to 5 show Embodiment 1 of the present invention. As shown in FIG. 1, the screw drop prevention tool 1 is used for an operation of loosening a screw 83 during energization of a terminal block 80 in a power facility such as a switchboard. The terminal block 80 includes a terminal block main body 81, a connection terminal 82 as a screwing member, and a screw 83. The terminal block body 81 is made of an insulating member, and a plurality of connection terminals 82 are arranged side by side. Each connection terminal 82 is partitioned through an insulating wall formed in the terminal block main body 81. Each connection terminal 82 is formed with a screw hole 82a into which a screw 83 is screwed.

  The screwdriver tool 90 is a tool for loosening the screw 83 of the terminal block 80 and has a handle portion 91 for an operator to grasp. The screwdriver tool 90 has a metal core bar 92 that is connected to the handle 91 and extends in the axial direction. The leading end 92 a of the core bar 92 can be engaged with the cross groove of the head 83 a of the screw 83. The handle 91 is electrically insulated from the core rod 92. The screw driver 90 can loosen the screw 83 engaged with the tip 92a by rotating the handle 91 around the axis with one hand.

  The screw drop prevention tool 1 has an inner insulating cylinder 10, an outer insulating cylinder 20, an electric insulating cover 30, and a first compression coil spring 40 as an urging means. The inner insulating cylinder 10 includes a first inner insulating cylinder 11 and a second inner insulating cylinder 12. The 1st inner side insulation cylinder 11 is comprised from the cylindrical member which has the electrical insulation which can insert the core rod 92 of the screwdriver tool 90. FIG.

  The 1st inner side insulation cylinder 11 is comprised from transparent or semi-transparent resin which has electrical insulation, and is formed in the cylindrical shape. The inner peripheral surface 11 a of the first inner insulating cylinder 11 has a function as a guide surface that guides the core rod 92 of the screwdriver tool 90 toward the screw 83. The outer peripheral surface 11b of the first inner insulating cylinder 11 has a function as a guide surface that holds the second inner insulating cylinder 12 so as to be movable in the axial direction. One of the first inner insulating cylinders 11 in the axial direction is formed at an open end 11c into which the core rod 92 of the screwdriver tool 90 can be inserted. The other of the first inner insulating cylinders 11 in the axial direction is opened so that the core rod 92 of the screwdriver tool 90 can be inserted, and the outer peripheral surface 11b side bulges outward in the radial direction. It is formed in the stopper portion 11d. The first stopper portion 11d has a function of regulating the movement of the second inner insulating cylinder 12 in the axial direction.

  The second inner insulating cylinder 12 is made of a transparent or translucent resin having electrical insulation. The second inner insulating cylinder 12 is provided outside the first inner insulating cylinder 11, and the other in the axial direction is formed in a cylindrical sliding cylinder portion 121. The inner peripheral surface 121 a of the sliding cylinder 121 is slidable with respect to the outer peripheral surface 11 b of the first inner insulating cylinder 11. The outer peripheral surface 121b of the sliding cylinder 121 has a function as a guide surface that holds the outer insulating cylinder 20 so as to be movable in the axial direction. The other of the second inner insulating cylinders 12 in the axial direction is formed at an open end 121c from which the first inner insulating cylinder 11 can protrude.

  One of the second inner insulating cylinders 12 in the axial direction is formed with a catch portion 122 that can elastically deform in the radial direction and can grip the head 83 a of the screw 83 that is loosened by the screwdriver tool 90. As shown in FIG. 3, one of the catch portions 122 is divided into a plurality in the circumferential direction, and the other is converged on the sliding tube portion 121 side of the second inner insulating tube 11. In the first embodiment, one of the catch portions 122 is separated into three in the circumferential direction by a plurality of cut portions 122e. The catch part 122 has a first pressing surface 122a, a gripping part 122b, a tapered part 122c, and a second stopper part 122d. The first pressing surface 122a is formed on the tip end surface of the catch portion 122 in the axial direction, and can come into contact with the screwing member 82 side to which the screw 83 is screwed. The second stopper portion 122d of the second inner insulating cylinder 12 can engage with the first stopper portion 11d of the first inner insulating cylinder 11 in the axial direction.

  The grip portion 122b protrudes radially inward from the axial tip of the catch portion 122. The grip portion 122b can be engaged with the outer peripheral portion of the head portion 82a of the screw 83 in the axial direction. In the first embodiment, the tip end surface of the grip portion 122b in the axial direction coincides with the first pressing surface 122a. When the tapered portion 122c comes into contact with the inner end 22a of the reduced diameter portion 22 of the outer insulating cylinder 20, the catch portion 122 is displaced inward in the radial direction so that the head portion 82a of the screw 83 is held by the gripping portion 122b. It is designed to grip.

  The outer insulating cylinder 20 is provided outside the inner insulating cylinder 10 and is movable in the axial direction with respect to the inner insulating cylinder 10. The outer insulating cylinder 20 is made of a transparent or translucent resin having electrical insulation, and is formed in a cylindrical shape. The outer insulating cylinder 20 has a holding cylinder part 21 that covers the outer periphery of the catch part 122 of the second inner insulating cylinder 12 on one side in the axial direction. The front end surface of the holding cylinder portion 21 in the axial direction is formed on a second pressing surface 21c that can contact the screwing member 82 side. The outer insulating cylinder 20 is formed with a reduced diameter portion 22 that is smaller than the diameter of the holding cylinder portion 21 on the other side in the axial direction. One side of the reduced diameter portion 22 in the axial direction has the inner insulating cylinder 10 in the axial direction with respect to the outer insulating cylinder 20 in a state where the second pressing surface 21c is in contact with the connection terminal 82 side as a screwing member. The inner surface end portion 22a is formed to displace the catch portion 122 radially inward by contact with the taper portion 122c when retracted by a predetermined distance. A third stopper portion 22b bulging outward in the radial direction is formed on the other axial side of the reduced diameter portion 22.

  The metal first compression coil spring 40 as the urging means is provided on the outer periphery of the inner insulating cylinder 10. One of the first compression coil springs 40 is in contact with the third stopper portion 22 b of the outer insulating cylinder 20, and the other is in contact with the end tool 30 c of the electrical insulating cover 30. The first compression coil spring 40 extends the outer insulating cylinder 20 in the axial direction in a direction in which the second pressing surface 21c of the outer insulating cylinder 20 protrudes from the first pressing surface 122a of the second inner insulating cylinder 12 in the axial direction. Energized. The first compression coil spring 40 is compressed in the axial direction in a state where the first pressing surface 122 a and the second pressing surface 21 c are in contact with the connection terminal 82 side, and is insulated from the outer insulating cylinder 20 on the inner side. The tube 10 is urged in the direction of retreating.

  The first compression coil spring 40 is covered with an electrical insulating cover 30 provided outside the inner insulating cylinder 10. The electrically insulating cover 30 is made of, for example, an opaque resin, and the cover main body 30a located on the outer periphery of the compression coil spring 40 is formed in a cylindrical shape. The electrical insulating cover 30 is formed with a third stopper portion 22b of the outer insulating cylinder 20 on one side in the axial direction and a fourth stopper portion 22b that is engaged in the axial direction, and a pressing wall 30c on the other side in the axial direction. Is formed.

  Between the outer peripheral surface 11b of the first inner insulating cylinder 11 and the inner side of the first compression coil spring 40, the second inner insulating cylinder 12 is urged in the axial direction with respect to the first inner insulating cylinder 11. A second compression spring 50 is provided. One of the second compression springs 50 in the axial direction is in contact with the end surface 121 c of the second inner insulating cylinder 12, and the other in the axial direction is in contact with the pressing wall 30 c of the electrical insulating cover 30. The diameter of the wire rod of the second compression spring 50 is larger than the diameter of the wire rod of the first compression spring 40. Thereby, the urging force of the second compression spring 50 is set larger than the urging force of the first compression coil spring 40.

  FIG. 4 shows the structure of the length adjusting portion M provided in the outer insulating cylinder 20. The length adjusting unit M has a function of adjusting the protruding length in the axial direction of the second pressing surface 21 c with respect to the first pressing surface 122 a by the first compression coil spring 40. The length adjusting portion M is composed of a male screw portion 221 and a female screw portion 222 formed in the reduced diameter portion 22 of the outer insulating cylinder 20. The length adjusting portion M can change the axial length of the reduced diameter portion 22 by adjusting the screwing length of the male screw portion 221 and the female screw 222. That is, by adjusting the distance L between the third stopper portion 22b and the fourth stopper portion 30b by the length adjusting portion M, the axial direction of the second pressing surface 21c with respect to the first pressing surface 122a. It is possible to adjust the protruding length of the. In a state where the length in the axial direction is adjusted, the movement of the female screw portion 222 around the axial center relative to the male screw portion 221 is restricted by the tube-shaped elastic ring 23.

  Next, the work procedure and operation when the screw 83 is loosened using the screw drop prevention tool 1 will be described.

  As shown in FIG. 5A, when loosening the screw 83, first, the core rod 92 of the tool 90 is inserted into the inner insulating cylinder 10 of the screw fall prevention tool 1. Then, the screwdriver 90 is moved in the axial direction until the handle 91 comes into contact with the pressing wall 30c of the electrical insulating cover 30. In this state, the second pressing surface 21c protrudes from the first pressing surface 122a by a distance L in the axial direction. Further, the tip end portion 92 a of the core rod 92 of the screwdriver tool 90 is located in the vicinity of the grip portion 122 b of the second inner insulating cylinder 12.

  Next, as shown by an arrow F1 in FIG. 5A, the screwdriver tool 90 is moved toward the terminal block 80, and the screw 83 is screwed onto the second pressing surface 21c of the outer insulating cylinder 20. Contact the connection terminal 82 side. When the screwdriver tool 90 is continuously pressed in the direction of the arrow F1, as shown in FIG. 5B, the first pressing surface 122a of the second inner insulating cylinder 12 is in contact with the connection terminal 82 side. Become. In this state, the tip end portion 92 a of the core rod 92 of the screwdriver tool 90 is not yet engaged with the cross groove of the head portion 83 a of the screw 83. Further, when the screwdriver 90 is continuously pressed with a strong force in the direction of the arrow F1, the second compression spring 50 is elastically deformed in the axial direction, and the tip 92a of the screwdriver 90 is a cross groove in the head 83a of the screw 83. Will be engaged.

  As shown in FIG. 5B, in a state where both the first pressing surface 122a and the second pressing surface 21c are in contact with the connection terminal 82 side, the tapered portion 122c of the catch portion 122 is reduced in diameter. Therefore, the grip portion 122b is displaced radially outward and away from the head portion 83a of the screw 83. By rotating the handle portion 91 of the screwdriver tool 90 in the direction around the axis (the direction of the arrow F2) with the tip portion 92a of the screwdriver tool 90 engaged with the cross groove of the head portion 83a of the screw 83, The screw 83 is loosened with the connection terminal 82, and the screw 83 moves in the axial direction (arrow F3). As a result, the head 83 a of the screw 83 is separated from the connection terminal 82.

  In a state where the screw 83 is completely loosened by the screwdriver 90, the grip portion 122b of the catch portion 122 is positioned between the connection terminal 82 and the head portion 83a of the screw 83. When the second pressing surface 21c is in contact with the connection terminal 82 side, the first compression spring is released by releasing (stopping) pressing in the axial direction (arrow F1 direction) of the screwdriver tool 90 by the operator. Due to the urging force of 40, the inner insulating cylinder 10 moves in the backward direction (arrow F4) with respect to the outer insulating cylinder 20. In this state, as shown in FIG. 5C, the tapered portion 122c of the catch portion 122 contacts the inner surface end portion 22a of the reduced diameter portion 22 of the outer insulating cylinder 20, and the grip portion 122b is displaced inward in the radial direction. Thus, the head portion 82a of the screw 82 is gripped by the grip portion 122b.

  In this way, in the state where the second pressing surface 21c of the outer insulating cylinder 20 is in contact with the connection terminal 82 side of the terminal block 80, the axial direction (arrow F1 direction) pressing by the screwdriver tool 90 is released. As a result, the head 83 a of the screw 83 can be gripped by the catch portion 122 by the retraction of the inner insulating cylinder 10. Therefore, the screw 83 loosened by the screwdriver 90 can be reliably recovered with only one hand operation, and curing with an insulating sheet is not required. Further, since the operation can be performed only with one hand, when loosening the screw 83, the wiring (not shown) connected to the connection terminal 82 side of the terminal block 80 via the screw 38 is held with the other hand. Can work safely. That is, the wiring (not shown) connected to the connection terminal 82 side of the terminal block 80 has a crimp terminal portion made of a conductor into which a screw 83 is inserted at the tip, and the screw 83 is connected to the connection terminal 82. When removed, the crimp terminal may be displaced in an unspecified direction, so holding this wire with the other hand avoids contact with other parts of the crimp terminal that are energized. Can be performed safely. Furthermore, since the head 83a of the screw 83 is gripped by the catch portion 122, even the screw 83 made of a non-ferrous metal such as brass that cannot be attracted by the magnet can be reliably recovered without dropping.

  Since the outer insulating cylinder 20 is provided with the length adjusting portion M for adjusting the protruding length in the axial direction of the second pressing surface 21c with respect to the first pressing surface 122a by the first compression coil spring 40, The protruding length of the outer insulating cylinder 20 can be adjusted in accordance with the length of the screw 38, and various screws can be gripped. Further, since the first compression coil spring 40 is covered by the electrical insulating cover 30 provided outside the inner insulating cylinder 10, the first compression coil spring 40 is not exposed to the outside, and an electric shock is prevented. Safety can be increased. And since the inner side insulation cylinder 10 and the outer side insulation cylinder 20 are comprised from the transparent or semi-transparent resin which has electrical insulation, the state of the screw | thread 83 loosened with the screwdriver tool 90 can be confirmed from the outside. , Can increase the work efficiency.

  In the first embodiment, since the second compression coil spring 50 is provided, the second inner insulating cylinder 12 of the inner insulating cylinder 10 is pressed by pressing the handle 91 of the screwdriver tool 90 in the axial direction. Is pressed in the axial direction via the second compression coil spring 50. The first pressing surface 122a of the second inner insulating cylinder 12 is connected to the terminal 82 side of the terminal block 80 in a state where the tip 92a of the screwdriver tool 90 is engaged with the cross groove of the head 83a of the screw 83. Will be in contact with. In other words, in the first embodiment, even if the axial lengths of the core rod 92 of the screwdriver tool 90 are slightly different, the screwdriver tool 90 has the tip 92a and the cross groove of the head 83a of the screw 83. By pressing in the axial direction until it is engaged, the first pressing surface 122a of the second inner insulating cylinder 12 can be reliably brought into contact with the connection terminal 82 side of the terminal block 80. Therefore, the screw fall prevention tool 1 of FIG. 1 can be applied to various screwdriver tools 90 having different lengths of the core rod 92.

(Embodiment 2)
FIG. 6 shows a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is only the structure of the inner insulating cylinder 10, and the other parts are the same as those of the first embodiment. Therefore, the same parts as those of the first embodiment are denoted by the same reference numerals. Therefore, the description of the order is omitted.

  In the first embodiment, the inner insulating cylinder 10 is composed of a first inner insulating cylinder 11 and a second inner insulating cylinder 12, but in the second embodiment, the inner insulating cylinder 10 is: It consists only of the second inner insulating cylinder 12 '. That is, in the first embodiment, in consideration of the case where the axial lengths of the core rod 92 of the screwdriver tool 90 are different, the inner insulating cylinder 10 includes two inner insulating cylinders 11 divided in the axial direction, However, in the second embodiment, since the dedicated screwdriver 90 is used for the screw fall prevention tool 1, the first inner insulating cylinder 11 is not necessary.

  As shown in FIG. 6, the inner peripheral surface 121 a of the sliding cylinder 121 of the second inner insulating cylinder 12 has a function as a guide surface for guiding the core rod 92 of the screwdriver tool 90 toward the screw 83. is doing. A first compression coil spring 40 is provided outside the outer peripheral surface 121 b of the sliding cylinder 121. The outer peripheral surface 121b of the sliding cylinder part 121 is smoothly connected to the outer peripheral surface of the tapered part 122c of the catch part 122. In the second embodiment, immediately before the handle portion 91 of the screwdriver tool 90 comes into contact with the pressing wall 30c of the electrical insulating cover 30, the tip end portion 92a of the core rod 92 of the screwdriver tool 90 is connected to the head portion 83a of the screw 83. It is designed to engage with the cross groove.

  In the second embodiment configured as described above, the screwdriver 90 is moved toward the terminal block 80, and the connection terminal 82 in which the second pressing surface 21c of the outer insulating cylinder 20 is screwed with the screw 83 is connected. Contact side. When the screwdriver tool 90 is pressed in the axial direction in this state, the first compression spring 40 is contracted in the axial direction, and the first pressing surface 122a of the second inner insulating cylinder 12 is in contact with the connection terminal 82 side. It becomes. In this state, the tip end portion 92 a of the core rod 92 of the screwdriver tool 90 is engaged with the cross groove of the head portion 83 a of the screw 83.

  Next, by rotating the handle portion 91 of the screwdriver tool 90 in the direction around the axis, the screw 83 is loosely engaged with the connection terminal 82, and the head portion 83 a of the screw 83 is separated from the connection terminal 82. become.

  In a state where the screw 83 is completely loosened by the screwdriver 90, the grip portion 122b of the catch portion 122 is positioned between the connection terminal 82 and the head portion 83a of the screw 83. With the second pressing surface 21c in contact with the connection terminal 82 side, the pressing force of the first compression spring 40 is released by releasing (stopping) the pressing of the screwdriver tool 90 in the axial direction by the operator. The inner insulating cylinder 10 moves in the backward direction with respect to the outer insulating cylinder 20. In this state, the taper portion 122c of the catch portion 122 contacts the inner surface end portion 22a of the reduced diameter portion 22 of the outer insulating cylinder 20, and the grip portion 122b is displaced inward in the radial direction. Is gripped by the gripping portion 122b.

  Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to the above-described first and second embodiments, and there are design changes and the like within the scope not departing from the gist of the present invention. However, it is included in this invention. For example, in the first embodiment, the case where the screw 83 of the terminal block 80 of the control panel of the power equipment is loosened has been described, but the target screw 83 is not only the terminal block 80 but also a screw of a machine tool, for example. May be. In this case, it is possible to have the screwdriver tool 90 with the screw drop prevention tool 1 mounted in one hand and the illumination light in the other hand. Further, the screw 83 to be loosened is not necessarily limited to the one that is energized, and is not limited to an electrical device as long as it is a device that is required to prevent the screw 83 from falling.

DESCRIPTION OF SYMBOLS 1 Screw fall prevention tool 10 Inner insulating cylinder 11 1st inner insulating cylinder 12 2nd inner insulating cylinder 122 Catch part 122a 1st press surface 122b Gripping part 122c Taper part 20 Outer insulating cylinder 21 Holding cylinder part 21c 2nd Press surface 22 Reduced diameter portion 22a Inner surface end 30 Electrical insulating cover 40 First compression coil spring (biasing means)
50 Second compression coil spring 80 Terminal block 82 Connection terminal (screwing member)
83 Screw 90 Screwdriver

Claims (4)

It is composed of an electrically insulating cylindrical member into which a screwdriver tool can be inserted, and has a catch portion capable of gripping the head of a screw that can be elastically deformed in the radial direction and loosened by the screwdriver tool in one of the axial directions. And an inner insulating cylinder formed on the first pressing surface, the tip end surface of the catch portion in the axial direction being in contact with the screwing member side to which the screw is screwed,
It is comprised from the cylindrical member which has the electrical insulation which can be advanced / retracted with respect to the said inner side insulation cylinder, and has a holding cylinder part which covers the outer periphery of the said catch part in one side of an axial direction, The axis | shaft of this holding cylinder part An outer insulating cylinder formed on a second pressing surface whose tip surface in the direction can contact the screwing member side;
The first pressing surface is provided on the outer periphery of the inner insulating tube and biases the outer insulating tube in the axial direction in a direction in which the second pressing surface protrudes axially from the first pressing surface. And in the state where the second pressing surface is in contact with the screwing member side, an urging means for urging the outer insulating cylinder in a direction to retract the inner insulating cylinder;
With
The catch portion is configured such that the inner insulating tube is moved against the outer insulating tube by a biasing force of the biasing means from a state where the first pressing surface and the second pressing surface are in contact with the screwing member side. And a screw fall prevention device that is displaced radially inward by contact with a reduced diameter portion formed on the outer insulating cylinder when the shaft is retracted by a predetermined distance in the axial direction.   At least one of the inner insulating cylinder and the outer insulating cylinder is provided with a length adjusting unit that adjusts the protruding length in the axial direction of the second pressing surface with respect to the first pressing surface by the biasing means. The screw fall prevention tool according to claim 1, wherein the screw fall prevention tool is provided.   2. The urging means is composed of a metal compression coil spring, and the compression coil spring is covered with an electrically insulating cover provided outside the inner insulating cylinder. Or the screw fall prevention tool of 2.   The screw fall prevention tool according to any one of claims 1 to 3, wherein the inner insulating cylinder and the outer insulating cylinder are made of a transparent or translucent resin.

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