WO2023286404A1

WO2023286404A1 - Rotation lock device and hoisting machine

Info

Publication number: WO2023286404A1
Application number: PCT/JP2022/016822
Authority: WO
Inventors: 貴幸河西
Original assignee: 株式会社キトー
Priority date: 2021-07-14
Filing date: 2022-03-31
Publication date: 2023-01-19
Also published as: CN117597301A; JPWO2023286404A1; DE112022003535T5

Abstract

Provided are a rotation lock device and hoisting machine capable of preventing a shaft-shaped member from becoming unrotatable due to unintentional actuation when the shaft-shaped member is rotated in the hoisting direction.　A holding plate 140 of a rotation lock device 100 has a guide groove 145 that engages a stopper projection 131 and holds a stopper member 130 in a prescribed position in the radial direction of a stopper support member 120. The other side of the guide groove 145 in the circumferential direction is provided with a third restriction wall 145d1 that prevents the holding plate 140 from rotating relative to the stopper support member 120 in the second rotational direction opposite to the first rotational direction, by engaging the stopper member 130 at a position where the stopper member 130 protrudes radially outward. When the stopper projection 131 is engaged with the third restriction wall 145d1, the stopper member 130 and the stopper locking means 120 are located at the non-locking site.

Description

Rotation locking device and hoist

The present invention relates to a rotation lock device and a hoist.

Lever hoists are widely used for tasks such as lifting and pulling loads, and securing loads with slings (tightening loads). This lever hoist can wind up (rewind) and lower (rewind) the chain by manually operating the operation lever. As such a lever hoist, for example, there is one disclosed in Patent Document 1. In the lever hoist shown in Patent Document 1, in addition to the conventional brake mechanism (mechanical brake), two centrifugal force members (31) and their centrifugal A housing ring (35) is provided which houses the force member (31). The centrifugal force member (31) is pressed against the inner peripheral surface of the housing ring (35) by the action of centrifugal force. This reduces the speed at which the load falls.

The above brake mechanism (mechanical brake) is configured as shown in Patent Document 2, for example. This brake mechanism comprises a pressure receiving member (7) non-rotatably attached to the drive shaft (4), a drive member (8) screwed onto the drive shaft (4), and a pair of brake plates (10a, 10b). , a ratchet wheel (11) for preventing reverse rotation, and a ratchet pawl (12) attached to a pawl shaft (15). The ratchet pawl (12) is urged by the spring (13) so that the ratchet pawl (12) is engaged with the locking teeth (11a) of the ratchet wheel (11). This engagement prevents the ratchet wheel (11) from rotating in reverse, thereby forming a mechanism in which a braking force acts on the rotation of the drive shaft (4) in the lowering direction.

DE102015121581A1 Japanese Patent Application Laid-Open No. 2008-230726

By the way, when hoists (lever hoists and chain blocks) are hoisted, a brake mechanism (mechanical brake) having a pawl wheel having a large number of ratchet teeth formed on the outer periphery and a ratchet mechanism having a pawl member that engages with the ratchet teeth is used. For example, if a meshing failure or damage occurs between the engaging tooth (11a) of the ratchet wheel (11) and the ratchet pawl (12) as shown in Patent Document 2, there is a possibility that the ratchet pawl (12) will not function. When the brake fails to function, the load sheave that winds the chain begins to rotate vigorously in the lowering direction due to the load of the suspended load, which may cause the load to drop.

Here, when the brake mechanism fails, in the configuration disclosed in Patent Document 1, the centrifugal force member (31) is pressed against the inner peripheral surface of the housing ring (35) due to the action of centrifugal force, thereby causing the load to drop. The speed (ie, the speed of rotation of the pinion) can be slowed down. However, it cannot stop the load from falling.

Further, in the configuration shown in Patent Document 2, the pawl shaft (15) is attached to the frame (1b) by press fitting or the like. However, since the thickness of the frame (1b) is relatively thin, the longer the pawl shaft (15), the greater the moment acting on the pawl shaft (15). However, if the pawl shaft (15) is attached by press-fitting it into the hole of the frame (1b), there is a limit to how much the mounting strength can be improved.

Therefore, the development of a rotation lock device that can reliably stop the load from falling (rotating in the lowering direction) even when the brake device fails is being developed.

By the way, in the rotation lock device under development as described above, when the lower hook attached to the lower end of the load chain is hooked on a suspended load or the like and the hoisting operation is started, the load chain may If there is slack, it takes time to remove the slack in the chain by operating the lever. For this reason, in some work sites, the slack in the load chain is eliminated at once by performing a hoisting operation such as pulling the unloaded side of the load chain vigorously. However, in the above-described rotation lock device, when the slack in the load chain is eliminated, the rotation of the shaft-shaped member suddenly stops or decelerates. In that case, there is a risk that the rotation lock device will be unintentionally activated even though the load is not actually dropped (the movement is in the hoisting direction), and it will take time and effort to restore the rotation lock device. There is a problem that arises.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is capable of reliably stopping the rotation of the shaft-like member in the hoisting direction in the event of a failure of the brake device. To provide a rotation lock device and a hoist capable of preventing a shaft-like member from becoming unrotatable due to unintentional operation when a shaft-like member is rotated.

In order to solve the above problems, according to a first aspect of the present invention, a stopper supporting member is attached to a shaft-like member and rotates integrally with the shaft-like member; a stopper member supported by the stopper supporting member in a slidable state toward the side; a holding plate that holds a predetermined position; a biasing means that biases the holding plate toward a first rotation direction, which is one direction of rotation, with respect to the stopper support member; stopper locking means for stopping the rotation of the stopper member, the stopper member having a stopper projection projecting toward the holding plate, the holding plate engaging with the stopper projection and moving the stopper member in the radial direction of the stopper support member The guide groove has a guide groove that holds the stopper member at a predetermined position in the radial direction, and the guide groove is formed by a first restricting wall that is formed by an arc concentric with the shaft-like member, and a second regulating wall that engages at a position where the stopper member protrudes radially outward from a predetermined position; the second regulating wall is provided on one side of the guide groove in the circumferential direction; accelerates its rotation in the first rotation direction, the stopper supporting member and the holding plate rotate relatively against the biasing force of the biasing means, and the stopper protrusion is separated from the first regulating wall. When the locking is released, the stopper member protrudes from a predetermined position to a position where it engages with the stopper locking means to stop the rotation of the shaft-shaped member. By engaging with the stopper member at a position where the stopper member protrudes radially outward from a predetermined position in , the holding plate is moved relatively to the stopper support member in a second rotation direction opposite to the first rotation direction. A third restricting wall is provided to prevent rotation, and when the stopper protrusion is engaged with the third restricting wall, the stopper member and the stopper locking means are positioned at a position where they are not locked. There is provided a rotation lock device for

Further, in the above-described invention, a return plate for returning the stopper member to a predetermined position on the axial center side is provided on the other side of the third restricting wall in the circumferential direction. Preferably, a guide wall is provided, and the return guide wall is inclined toward the inner diameter side from one circumferential side to the other side.

Further, in the invention described above, it is preferable that the third restricting wall and the return guide wall are provided on the inner wall of the movement restricting groove.

In the above-described invention, the stopper supporting member is made of a soft magnetic material, and a magnetic force is exerted in a mutually attracting direction on at least one of the radially inner diameter side of the stopper member and the opposing portion of the stopper supporting member. A magnet is preferably attached.

Further, in the above-described invention, it is preferable that magnets exerting a magnetic force in mutually attracting directions are attached to both the radially inner diameter side of the stopper member and the facing portion of the stopper support member.

Further, in the above-described invention, the holding plate is provided with projecting means that projects from the front surface or the back surface of the holding plate, and the projecting means is urged by the urging means to urge the holding plate in the first rotation direction. When the stopper protrusion contacts the end of the guide groove opposite to the first rotation direction, the stopper protrusion contacts the side surface of the stopper support member before or simultaneously with the contact. preferable.

Further, in the above-described invention, the holding plate is provided with a spring receiving projection that is formed by bending a portion of the holding plate and that is arranged on the outer diameter side of the holding plate relative to the biasing means. Preferably, the spring-receiving protrusions receive the biasing means from falling off toward the outer diameter side due to the centrifugal force generated when the holding plate rotates.

In order to solve the above problems, according to a second aspect of the present invention, a load sheave is pivotally supported by a pair of frames and around which a chain for lifting a load is wound; A hoisting machine comprising a connected drive shaft, a brake device attached to the drive shaft, and an operation lever for rotating and driving a load sheave in the hoisting and lowering directions, the hoisting machine comprising: is provided with the rotation lock device according to each of the above-described inventions, the shaft-like member is a drive shaft, and the stopper locking means is attached to the frame. be.

According to the present invention, it is possible to reliably stop the rotation of the shaft-shaped member in the hoisting direction when the brake device fails, etc., and when the shaft-shaped member is rotated in the hoisting direction, the intended It is possible to provide a rotation lock device and a hoist that can prevent the shaft-shaped member from becoming unrotatable due to the operation without the rotation.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows an example of a structure of the lever hoist to which the rotation lock (load fall prevention) apparatus which concerns on the 1st Embodiment of this invention is attached. FIG. 2 is a cross-sectional view showing the configuration of the lever hoist shown in FIG. 1; FIG. 2 is a cross-sectional view showing a configuration around a rotation lock (load drop prevention) device in the lever hoist shown in FIG. 1; FIG. 4 is an exploded perspective view showing the configuration of the rotation lock (load drop prevention) device shown in FIG. 3; It is a top view which transparently shows a guide groove while showing a stopper member among lever hoists shown in FIG. It is a front view which shows the holding plate located in the X1 side among the lever hoists shown in FIG. It is a front view which shows the holding plate located in the X2 side among the lever hoists shown in FIG. FIG. 2 is a view showing the configuration around a rotation lock (load drop prevention) device in the lever hoist shown in FIG. 1 and transparently showing the positional relationship of each part before the operation of the rotation lock (load drop prevention) device. FIG. 9 is a diagram transparently showing the positional relationship of each part in a state where the stopper support member and the holding plate have relatively rotated from the state shown in FIG. 8 and the stopper projection has reached the allowable groove. FIG. 10 is a view transparently showing the positional relationship of each part in a state in which the stopper member protrudes radially outward from the state shown in FIG. 9 and the stopper protrusion is positioned in the return restricting groove. FIG. 9 is a diagram transparently showing the positional relationship of each part in a state where the stopper support member and the holding plate are relatively rotated from the state shown in FIG. 8 and the stopper projection enters the movement restricting groove. 12 is an enlarged view showing the positional relationship in the vicinity of the movement restricting groove portion in the state shown in FIG. 11; FIG. FIG. 13 is an enlarged view showing a state in which the stopper projection slides along the return guide wall due to the action of the pulling force of the urging spring from the state shown in FIG. 12; FIG. 10 is a diagram showing a state in which a magnet is arranged in a concave portion on the bottom side of a stopper member 130 and a magnet is also arranged in a concave portion on the bottom side of a stopper support member according to a modification of the present invention; 14A is a diagram showing a state in which two magnets are separated by a distance Y in the configuration shown in FIG. 14, and FIG. FIG. 10 is a diagram showing a state in which the

[First embodiment]
A lever hoist 10 according to a first embodiment of the present invention will be described below with reference to the drawings. In the following description, the X direction is the axial direction of the drive shaft 25, the X1 side is the side to which the free rotation barb 60 is attached, and the X2 side is the opposite gear box 34 side. The Z direction is the vertical direction (suspension direction; hoisting and lowering direction) in the suspended state of the lever hoist 10, the Z1 side is the upper side in the suspended state, and the Z2 side is the lower side in the suspended state. A direction orthogonal to the X direction and the Z direction is the Y direction, the Y1 side is the right side in FIG. 1, and the Y2 side is the left side in FIG. Further, in the following description, the rotation direction of the load sheave 20 is defined as one rotation direction for lowering and the other rotation direction for lifting. Further, the direction of rotation about the axis connected to the load sheave 20 is based on the direction in which the load sheave 20 is rotated.

<Regarding the overall structure of the lever hoist>
FIG. 1 is a front view showing an example of the configuration of a lever hoist 10 according to the first embodiment of the invention. FIG. 2 is a sectional view showing the structure of the lever hoist 10 shown in FIG. 1. As shown in FIG.

As shown in FIG. 2, between a pair of

frames

11 and 12 of the lever hoist 10, a load sheave 20 around which a chain C1 is wound is rotatably supported. The load sheave 20 is non-rotatably provided with a load gear 21 that meshes with a small-diameter gear portion 32 of a reduction gear 30, which will be described later. The details of the configuration of the load sheave 20 will be described later.

Further, the load sheave 20 has an insertion hole 20a that penetrates in the axial direction (X direction), and a drive shaft 25 is inserted through the hollow hole of the load sheave 20. In addition, the drive shaft 25 corresponds to a shaft-like member. A male threaded portion 26 that meshes with a female threaded member 35 constituting a brake device 70 to be described later is provided on the outer peripheral side of the middle of the drive shaft 25 . A pinion gear 27 that meshes with the diameter gear portion 31 is provided. The reduction gear 30 is also integrally provided with a small-diameter gear portion 32 that meshes with the load gear 21 described above.

A casing 13 is attached to the frame 11 to protect drive parts such as the reduction gear 30 and the load gear 21 described above. Further, the male threaded portion 26 described above is engaged with the female threaded portion 36 of the female threaded member 35 . In addition to the female threaded portion 36 , the female threaded member 35 is also provided with a switching gear 37 that can mesh with the switching pawl 40 arranged on the operating lever 50 . The switching pawl 40 is, for example, a ratchet pawl provided on one side and one on the other side. to transmit the driving force.

Further, a switching knob 45 is coaxially fixed to the switching claw 40, and by switching operation of the switching knob 45, the transmission of the driving force to the female screw member 35 is set in the winding up direction or the winding down direction. It is possible to switch between the neutral position. For example, when the lower side (Z2 side) of the switching knob 45 is tilted to the left in FIG. As a result, when the operation of swinging the operating lever 50 is repeated, the switching gear 37 rotates in the hoisting direction but does not rotate in the hoisting direction. At this time, it corresponds to the hoisted state of the chain C1.

On the other hand, for example, when the lower side (Z2 side) of the switching knob 45 is tilted to the right in FIG. As a result, when the operation of swinging the operating lever 50 is repeated, the switching gear 37 rotates in the lowering direction but does not rotate in the raising direction. Further, when switched to the neutral position, it is possible to shift to an idle rotation state (at this time, the load sheave 20 and the drive shaft 25 also rotate) in which the chain C1 can be pulled out by hand. Furthermore, the chain C1 can be quickly hoisted or lowered without operating the operation lever 50 by operating the free rotation grip 60, which will be described later.

A cam member 55 is attached to the drive shaft 25 in a non-rotatable state such as spline connection or key connection. Further, a member called an idle bar 60 is attached to the cam member 55 so as to be slidable in the axial direction by a predetermined amount. 2, the idle rotation barb 60 is non-rotatably engaged with the cam member 55, but when the idle rotation barb 60 is slid in the X1 direction, the idle rotation barb 60 is kept constant with respect to the cam member 55. It is rotatable within the range of The free rotation gripper 60 is a substantially cylindrical knob-shaped portion that can rotate together with the drive shaft 25 via the cam member 55, and can be gripped by the operator's hand.

The free rotation barb 60 is connected to the female screw member 35 by a first torsion spring (not shown), and further connected to one end of the drive shaft 25 by a second torsion spring (not shown). When the switch knob 45 is in the neutral position and the idle rotation grip 60 is slid in the X1 direction in FIG. 2, the idle rotation grip 60 rotates in the lowering direction by a predetermined amount due to the biasing force of the second torsion spring (idle rotation spring). The first torsion spring attached to the free rotation barb 60 that has rotated by a predetermined amount also rotates in the lowering direction, releasing the biasing force that has urged the female screw member 35 to rotate in the winding up direction until then, and switches to the free rotation mode. . Here, regardless of whether it is in the idle rotation mode or not, when the operator grips the idle rotation gripper 60 and rotates it in the hoisting direction, the rotational force can be transmitted to the drive shaft 25 . Therefore, by rotating the idle rotation gripper 60, it is possible to quickly adjust the length of the chain C1, and to switch to the idle rotation mode by sliding it. Also, in the idle rotation mode, when a tension exceeding a specified value acts on the chain C1 in the lowering direction, the female screw member 35 rotates in the tightening direction, which is the tightening direction, relative to the drive shaft 25, thereby causing a brake device 70 to be described later. brakes are activated.

<Regarding the brake device 70>
As shown in FIG. 2, a brake device 70 is arranged on the drive shaft 25 connected to the load sheave 20 via gears. The brake device 70 includes a brake receiver 71,

brake plates

72a and 72b, a ratchet wheel 80, a pawl member 90, a pawl shaft 115, a bushing 92, a female screw member 35, and the like as main components. The ratchet wheel 80, the pawl member 90 and the pawl shaft 115 correspond to the main components of the ratchet mechanism.

The brake receiver 71 has a flange portion 71a and a hollow boss portion 71b. The flange portion 71a is provided with a larger diameter than the hollow boss portion 71b, and is capable of receiving the brake plate 72a.

The hollow boss portion 71b is positioned closer to the female screw member 35 (X1 side) than the flange portion 71a, and pivotally supports the ratchet wheel 80 via the bush 92. The inner peripheral side of the hollow boss portion 71b is engaged with the drive shaft 25 by spline coupling or the like, so that the drive shaft 25 and the brake bearing 71 rotate integrally.

Between the flange portion 71a and the ratchet wheel 80 and between the female screw member 35 and the ratchet wheel 80,

brake plates

72a and 72b are pivotally supported by the hollow boss portion 71b, respectively. The

brake plates

72a and 72b are, for example, plate-shaped friction materials made of a predetermined friction material, or are arranged on both surfaces of the ratchet wheel 80 by sintering.

When the female threaded member 35 is rotated in the winding-up direction, the female threaded member 35 presses the ratchet wheel 80 together with the

brake plates

72a and 72b toward the brake receiver 71 by the action of the male threaded portion 26 of the drive shaft 25, thereby applying the driving force to the drive shaft. 25. On the other hand, even if the drive shaft 25 is rotated in the lowering direction in this state, the female screw member 35 presses the ratchet wheel 80 together with the

brake plates

72a and 72b toward the brake receiver 71. As shown in FIG. At this time, since the ratchet wheel 80 is prevented from rotating in the lowering direction by the pawl member 90, the brake device 70 is applied with a braking force due to frictional force. As a result, the rotation of the drive shaft 25 in the lowering direction can be stopped. Conversely, when the female screw member 35 is rotated in the lowering direction, the pressing force of the female screw member 35 is loosened by that amount, the braking force of the brake device 70 is reduced, and it is possible to rotate in the lowering direction.

Further, a pawl shaft 115 is integrally provided with the stopper support member 120 to be described later, and the pawl member 90 is rotatably supported on the pawl shaft 115 . A coil portion 93 a of a torsion spring 93 is attached to the pawl shaft 115 , and the torsion spring 93 provides an urging force in a direction in which the pawl member 90 is pressed against the ratchet teeth 83 of the pawl wheel 80 . In this manner, the ratchet wheel 80 is rotatable in the winding up direction and restricted in rotation in the winding down direction for each pitch angle divided by the number of teeth of the ratchet wheel 80 . A pair of pawl members 90 are provided and are arranged 180 degrees apart in the circumferential direction of the pawl wheel 80 .

As shown in FIG. 2, the brake device 70 is covered with the brake cover 14 to prevent dust, rainwater, and the like from entering the brake device 70 located inside the brake cover 14. ing.

<Regarding the load sheave 20 and the rotation lock (load drop prevention) device 100>
Next, the load sheave 20 and the rotation lock (load drop prevention) device 100 will be described. FIG. 3 is a sectional view showing the configuration around the rotation lock (load drop prevention) device 100. As shown in FIG. FIG. 4 is an exploded perspective view showing the configuration of the rotation lock (load drop prevention) device 100 shown in FIG. As shown in FIGS. 3 and 4, the rotation lock (load drop prevention) device 100 includes a stopper engaging member 110, a stopper supporting member 120, a stopper member 130, a holding plate 140, and an urging unit 150 as main components. there is Note that the stopper engaging member 110 corresponds to the stopper engaging means, and the biasing unit 150 corresponds to the biasing means.

As shown in FIGS. 2 to 4, in this embodiment, a pair of stopper locking members 110 are attached to the ratchet wheel 80 side of the frame 12 . In this embodiment, the stopper locking member 110 is a long piece-shaped member elongated in the Y direction, and a space SP1 is formed between the two stopper locking members 110 . Therefore, the stopper locking member 110 can be made lighter than when the stopper locking member is provided along the entire outer periphery of the stopper supporting member 120 and the holding plate 140. there is

Each stopper locking member 110 is attached to the frame 12 via two stay bolts B1. To enable such mounting, the stopper locking member 110 has two mounting holes 111. is provided, and a stay bolt B1 is inserted through the mounting hole 111 thereof. Although a pair (two) of mounting holes 111 are provided in this embodiment, three or more mounting holes 111 may be provided.

In addition, the stopper locking member 110 is provided with an inner protrusion 112 . The inner projecting portion 112 is a portion of the stopper locking member 110 that projects toward the center of the shaft hole 12b of the frame 12 . The shaft hole 12b is a hole for inserting the drive shaft 25 and the load sheave 20 described above.

The inner protruding portion 112 faces the outer peripheral surfaces of a stopper support member 120 and a holding plate 140, which will be described later, with a slight gap therebetween. As a result, the stopper support member 120 and the holding plate 140 that support the stopper member 130 at the holding position can be rotated without hindrance. In this embodiment, each stopper locking member 110 is provided with one. Therefore, two inner projecting portions 112 are arranged at intervals of 180 degrees in the circumferential direction.

In addition, a locking wall 114 is provided on the inner projecting portion 112 . The locking wall 114 is a wall surface on the other side in the rotation direction of the inner protrusion 112 (the clockwise side of the inner protrusion 112 in FIGS. 3 and 4). Rotation of the load sheave 20 can be stopped by colliding with the stopper member 130 rotating in the direction (lowering direction) when projecting radially outward from the stopper supporting member 120 . For this reason, the locking wall 114 is set at an angle of inclination with respect to the radial direction of the shaft hole 12b so as not to push back the stopper member 130, which will be described later, in the direction of the rotation axis. Moreover, the side surface of the stopper member 130 also has an inclined side surface that is not pushed back in the rotation axis direction when it collides with the locking wall 114 . In addition, as shown in FIG. 4, a recessed portion 113 is provided continuously with the locking wall 114 and is recessed in a direction away from the rotation axis direction (outer diameter side). One hook portion (not shown) of the torsion spring 93 is engaged with the concave portion 113 to avoid contact between the stopper member 130 and the hook portion of the torsion spring 93 .

Further, as shown in FIG. 4, the stopper locking member 110 is provided with a pawl shaft 115 . In the present embodiment, pawl shaft 115 is integrated with other portions of stopper locking member 110 . For such integration, stopper locking member 110 is preferably formed by casting (for example, the lost wax method). However, only the pawl shaft 115 may be separately formed, and the pawl shaft 115 may be press-fitted into a mounting hole or the like existing in the stopper locking member 110 to be attached.

Here, as shown in the cross-sectional view of FIG. 3, a plurality of ribs 116 are arranged inside the stopper locking member 110 . That is, the stopper locking member 110 is not a solid member but a member having a hollow portion composed of a plurality of ribs 116, so that the weight of the stopper locking member 110 can be reduced. Two ribs 116 are arranged on the root side of the pawl shaft 115 so as to draw an X, so that the load in the axial direction (thrust direction) of the pawl shaft 115 can be received.

Note that, in the present embodiment, as shown in FIG. 3 , the side wall of the inner projecting portion 112 on the side opposite to the locking wall 114 may also function as the locking wall 114 . 3 and 4 among the side walls facing the recessed portion 113 is inclined at a predetermined angle or more with respect to the radial direction, so that the stopper member 130 protruding from the stopper housing portion 123 is It may be configured to be stored in a stopper storage portion 123, which will be described later.

Next, the stopper support member 120 will be explained. The stopper support member 120 has a center hole 121 and is attached to the drive shaft 25 through the center hole 121 so that the stopper support member 120 and the drive shaft 25 rotate together. The stopper support member 120 may be attached to the drive shaft 25 by any method such as set screw, key connection, spline connection, etc., as long as the required torque can be transmitted.

Further, as shown in FIG. 4, the stopper support member 120 is provided with a bearing boss portion 122 . The bearing boss portion 122 is a hollow shaft-like portion protruding in the axial direction (X direction), and is rotatably fitted in a center hole 142 provided in the holding plate 140 .

Further, the stopper support member 120 is provided with a stopper storage portion 123 extending from the center hole 121 side toward the outer peripheral side. The stopper housing portion 123 is a portion for housing a stopper member 130, which will be described later, and its outer peripheral side is open. Therefore, the stopper member 130 housed in the stopper housing portion 123 can protrude toward the outer peripheral side, and is slidably supported by the side wall 123a of the stopper housing portion 123. As shown in FIG.

The stopper housing portion 123 is formed by being sandwiched between the narrow piece portion 120a and the wide piece portion 120b. When the later-described stopper member 130 collides with the locking wall 114, the narrow piece 120a is located at a position facing the inner projecting portion 112, while the wide piece 120b faces the inner projecting portion with the stopper accommodating portion 123 interposed therebetween. It is located at a site away from 112 (locking wall 114). In the configuration shown in FIG. 3 , the narrow piece 120 a is positioned on the left side of the stopper housing portion 123 and the wide piece portion 120 b is positioned on the right side of the stopper housing portion 123 . Here, the wide piece portion 120b is wider in the circumferential direction than the narrow piece portion 120a. Therefore, even if the stopper member 130 collides with the locking wall 114, the strength is ensured so that the impact is received by the wide piece 120b.

The stopper support member 120 is also provided with an insertion hole 124 . The insertion hole 124 is a hole recessed from a portion of the outer peripheral surface of the stopper support member 120 that does not interfere with the center hole 121 and the stopper housing portion 123. In FIG. ing. One end of a one-end locking pin 152 , which will be described later, is inserted into this insertion hole 124 , so that the stopper support member 120 supports the one-end locking pin 152 .

Next, the stopper member 130 will be explained. 5 is a plan view showing the stopper member 130 and the guide groove 145. FIG. As shown in FIGS. 3 to 5, the stopper member 130 is accommodated in the stopper accommodating portion 123 of the stopper supporting member 120 described above. The stopper member 130 is housed in the stopper housing portion 123 so as to be slidable in the centrifugal direction from the housed position.

In the configuration shown in FIG. 3, the bottom surface (the inner wall surface on the side of the rotation axis) 123a of the stopper housing portion 123 has a planar portion, so that the bottom surface 130a of the stopper member 130 (stopper housing portion) 123a has a planar portion. A surface located on the inner diameter side of the portion 123) also has a planar portion. A concave portion (reference numeral omitted) is formed on the bottom surface 130a side of the stopper member 130 for attaching a magnet M1 as will be described later.

As shown in FIG. 3, when the stopper member 130 is housed in the stopper housing portion 123 at a predetermined position, the outer peripheral surface of the stopper member 130 (the surface away from the center in the radial direction) is aligned with the rotation axis. On the other hand, it is located on the inner diameter side of the outer peripheral surface of the stopper support member 120 .

Here, the stopper member 130 is provided with a columnar stopper projection 131 . The stopper protrusion 131 protrudes in the X-axis direction toward the holding plate 140 from the surface (front surface and rear surface) of the stopper member 130 facing the holding plate 140 . 3 and 4, etc., the stopper protrusion 131 is positioned closer to the axis of the drive shaft 25 (the stopper member 130) than the center of the stopper member 130 in the depth direction (the radial direction of the stopper support member 120). located on the side. Further, the stopper projection 131 may be formed integrally with the stopper member 130, but the stopper projection 131 may be formed by providing a mounting hole in the stopper member 130 and fitting a shaft-like member, a pin, or the like into the mounting hole. You can do it.

This stopper projection 131 enters a guide groove 145, which will be described later. As a result, the stopper protrusion 131 slides in the guide groove 145 when the rotational positions of the stopper support member 120 and the holding plate 140 change relative to each other. When the stopper projection 131 is located in the allowable groove portion 145a, which will be described later, the centrifugal force acting on the stopper member 130 and the pressing force from the second restricting wall 145c1 due to the biasing force of the biasing spring 151 cause the stopper to move. It becomes possible for the member 130 to protrude to the outer diameter side.

Here, the outermost outer peripheral surface 132 of the stopper member 130 in the radial direction is formed in an arc like the outer peripheral surface of the stopper support member 120 and the outer peripheral surface of the holding plate 140 described above. However, the outer peripheral surface 132 may be provided linearly, or may be provided in another shape. Note that the radial direction of the stopper member 130 refers to the direction connecting the center of rotation of the drive shaft 25 and the outer diameter side (the same applies to other portions in this specification).

A magnet M1 is attached to the bottom surface 130a of the stopper member 130. The magnet M1 is a member that generates a magnetic force for returning the stopper member 130 protruding to the outer diameter side by the action of centrifugal force to the original storage position. Specifically, the magnet M1 is arranged so as to face the bottom surface 123b of the stopper housing portion 123 of the stopper support member 120 made of a soft magnetic material. Therefore, since the magnet M1 generates a magnetic force with the bottom surface 123b, the magnetic force increases as the magnet M1 approaches the bottom surface 123b, and the stopper member 130 is pulled back to the retracted position.

When the stopper supporting member 120 and the stopper member 130 are rotating, the magnetic force of the magnet M1 resists the centrifugal force until the stopper member 130 reaches a constant number of rotations (set number of rotations). It also has the function of suppressing protrusion into the Such a set number of rotations can be set to an appropriate number of rotations, which is normally used for guidance at high speed when the chain C1 is pulled. Further, since the stopper member 130 is held at a predetermined position (the position where the bottom surface 130a and the bottom surface 123b are in contact; the retracted position) of the stopper housing portion 123 by magnetic force, the stopper projection of the stopper member 130 is prevented from being rapidly accelerated from a stopped state. Since the sliding contact between 131 and the first restricting wall 145b1 of the holding plate 140 can be suppressed, there is also an effect that the operating value of the relative rotation of the holding plate 140 and the stopper support member 120 is stabilized.

Next, the holding plate 140 will be explained. In this embodiment, two holding plates 140 having different shapes are provided. In the following description, the holding plate 140 positioned on the X1 side in FIG. 4 is referred to as holding plate 140A, and the holding plate 140 positioned on the X2 side in FIG. 4 is referred to as holding plate 140B. However, when there is no need to distinguish between the two, they are simply referred to as holding plate 140 . A stopper support member 120 is sandwiched between the holding plate 140A and the holding plate 140B. The holding plates 140 are connected to each other by a connecting member R1 at a predetermined interval. It should be noted that it is preferable that the holding plates 140 are firmly connected to each other so as to be integrated.

FIG. 6 is a front view showing the holding plate 140A located on the X1 side. This holding plate 140A is provided in a disk shape (ring shape), and a center hole 142 is provided in the center in the radial direction. By fitting the bearing boss portion 122 of the stopper support member 120 into the center hole 142 , the holding plate 140 is coaxially and rotatably supported with respect to the stopper support member 120 . The distance (that is, the radius) from the center of rotation to the outermost periphery of the holding plate 140A is approximately the same as that to the outermost periphery of the stopper support member 120. As shown in FIG. However, either one of the stopper support member 120 and the holding plate 140A may be provided with a large radius.

FIG. 7 is a front view showing the holding plate 140B located on the X2 side. This holding plate 140B has a concave portion extending from the outer diameter side to the inner diameter side by punching or bending a plurality of circular ring-shaped positions (two positions in FIG. 7).

A locking projection 143 raised from the plate surface of the holding plate 140B is provided on one of these recessed portions. The locking protrusion 143 is a portion that abuts against the side surface 120b1 of the wide piece 120b of the stopper support member 120. Even if the stopper support member 120 is pulled by the urging spring 151 due to this contact, the stopper support member 120 is no longer pulled. , is in a non-rotating state. That is, the locking protrusion 143 regulates the rotational position of the stopper support member 120 in the winding-up direction with respect to the holding plate 140B. Therefore, it is possible to prevent the stopper projection 131 from receiving the urging force from the urging unit 150 at the end portion of the clearance groove portion 145b in the second rotation direction. Therefore, it is possible to reduce the influence on the behavior of the stopper member 130 due to the frictional force caused by the biasing force from the biasing unit 150 generated between the stopper member 130 and the side wall 123a, and the operation of the rotation lock device 100 can be stabilized. .

The side surface of the locking protrusion 143 is in contact with the side surface of the wide piece 120b. Moreover, the boundary line between the locking protrusion 143 and the plate surface is not along the radial direction of the holding plate 140B, but forms a predetermined angle with respect to the radial direction. Therefore, when the wide piece portion 120b collides with the locking protrusion 143, it prevents deformation such that the bending angle of the locking protrusion 143 with respect to the plate surface changes.

A spring receiving protrusion 144 raised from the plate surface of the holding plate 140B is provided on the other of the recessed portions as described above. As shown in FIG. 3, the spring receiving protrusion 144 is arranged on the outer diameter side of the holding plate 140B relative to the biasing spring 151, and when the holding plate 140 rotates, the biasing spring 151 is moved to the outer diameter side by centrifugal force. I'm accepting to drop off towards.

Also, the holding plate 140 is provided with a guide groove 145 . As shown in FIGS. 5 to 7, the guide groove 145 is a portion into which the stopper projection 131 of the stopper member 130 is inserted to guide the movement of the stopper projection 131. Its appearance is similar to the diameter of a substantially triangular portion. It has a shape with a long arc-shaped groove added to the center side of the direction. Specifically, the guide groove 145 has a substantially triangular holding projection 146 as shown in FIGS. 145b and a return restricting groove portion 145c are provided. In addition to these grooves, the guide groove 145 is provided with a movement restricting groove 145d.

The allowable groove portion 145a is a groove that allows the stopper projection 131 to move in the radial direction. 5 to 7, the inner wall 145a1 positioned below the allowable groove 145a is provided parallel to the radial direction (one radial direction extending from the center of the central hole 142). The width of the allowable groove portion 145a is defined by the distance between the tip end portion 146a of the holding projection portion 146 that protrudes most toward the inner wall 145a1 and the inner wall 145a1 described above.

In addition, the clearance groove portion 145b is a groove recessed from the tip end portion 146a of the convex portion so as to be distant from the allowance groove portion 145a in the circumferential direction (to the right in FIGS. 5 to 7). The gap groove portion 145b enables the stopper projection 131 to be positioned with play. A movement restricting groove portion 145d, which will be described later, is provided on the farthest side (the other end side) of the clearance groove portion 145b from the allowance groove portion 145a.

In addition, although there is an R-shaped portion (a rounded corner portion) at the end of the clearance groove portion 145b on the side of the allowance groove portion 145a, the radius of the R-shaped portion is equal to the radius of the stopper projection 131. is provided in Here, when the radius of the R-shaped portion is larger than the radius of the stopper projection 131, when the stopper projection 131 collides with the R-shaped portion, a force is applied to move the stopper projection 131 toward the outer diameter side. end up However, the radius of the R-shaped portion is set to the same dimension as the radius of the stopper projection 131, so that when the stopper projection 131 collides with the R-shaped portion, the force of moving the stopper projection 131 to the outer diameter side is reduced. prevent giving. The radius of the R-shaped portion may be set smaller than the radius of the stopper projection 131 .

Here, an inner wall (referred to as a first restricting wall 145b1) on the outer diameter side of the gap groove portion 145b is a wall surface that engages with the stopper projection 131 to hold the stopper member 130 at a predetermined position of the stopper support member 120. It has an arcuate wall surface concentric with the center hole 142 . When the stopper protrusion 131 is accommodated in the clearance groove portion 145b, the outer diameter side of the stopper member 130 is accommodated in the stopper accommodating portion 123 without protruding further to the outer diameter side than the outer peripheral surface of the stopper support member 120. It is

Here, the circumferential length of the clearance groove portion 145b is formed to be longer than the length determined by the angle γ described below. That is, when the ratchet wheel 80 is interrupted during the winding operation, it idles in the winding down direction by an angle (pitch angle) obtained by dividing one rotation by the number of teeth at maximum. Let this angle be an angle γ (not shown). In this case, it is preferable that the rotation lock device 100 also operates with a delay larger than the angle γ. Therefore, when the stopper member 130 is stored, the circumferential length of the clearance groove 145b into which the stopper projection 131 is inserted is set to be at least the angle γ or more. Then, until the holding plate 140 rotates relative to the stopper support member 120 at an angle of γ or more in the second rotation direction opposite to the lowering direction, the stopper member 130 is rotated. is preferably maintained.

It should be noted that, in the present embodiment, the clearance groove portion 145b is sufficiently longer than the angle γ. Here, when the length of the clearance groove portion 145b is short, after switching the switching knob 45 to the neutral position and operating the idle rotation gripper 60 to set the idle rotation mode, the chain C1 is quickly pulled out in the lowering direction. During the operation, the rotation lock device 100 is easily actuated, and the convenience of pulling out the chain C1 is reduced. Therefore, after switching the switching knob 45 to the neutral position to set the idle rotation mode, the length of the clearance groove portion 145b is set to It is sufficiently longer than the angle γ. This prevents the rotation lock device 100 from operating and causing a rotation lock state during the free rotation operation as described above.

In addition, the return restricting groove portion 145c is a groove that is recessed (upward in FIGS. 5 to 7) away from the allowable groove portion 145a in the circumferential direction. The return restricting groove portion 145c allows the stopper projection 131 to be positioned with play. However, the return restricting groove portion 145c is provided with a second restricting wall 145c1. The second restricting wall 145 c 1 engages with the stopper projection 131 so that the outer diameter side of the stopper member 130 is maintained in a state of protruding from the outer peripheral surface of the stopper support member 120 . That is, the second restricting wall 145c1 is a wall surface for restricting the stopper member 130 from being accommodated in the stopper accommodating portion 123. As shown in FIG.

The second restricting wall 145c1 is inclined so as to gradually approach the inner wall 145a1 toward the inner diameter side, and is in contact with the holding protrusion 146. As shown in FIG. Therefore, even if the rotational acceleration of the drive shaft 25 in the first rotation direction decreases after the stopper member 130 slides in the centrifugal direction from the predetermined position and the stopper projection 131 passes over the projection tip 146a, the stopper projection 131 is engaged with the second restricting wall 145c1, the stopper member 130 is securely engaged with the locking wall 114, and the engagement is maintained while the load on the drive shaft 25 in the first rotation direction continues. maintain. On the other hand, by rotating the stopper support member 120 and the stopper member 130 relative to the holding plate 140 in a state where the stopper projection 131 is inserted into the return restricting groove portion 145c, the stopper projection 131 moves toward the allowable groove portion 145a. Then, the engagement with the second regulation wall 145c1 is released. Thereby, the stopper member 130 can move toward the inner diameter side of the stopper housing portion 123 .

Further, the movement restriction groove portion 145d is a groove portion into which the stopper projection 131 attached to the stopper member 130 enters when the stopper support member 120 and the holding plate 140 are rotated at high speed in the winding direction. The movement restricting groove portion 145d is provided with a third restricting wall 145d1 and a return guide wall 145d2.

The third regulation wall 145d1 is a wall surface against which the stopper projection 131 collides. That is, the third restricting wall 145d1 comes into contact with the stopper protrusion 131 of the stopper member 130 that has moved into the movement restricting groove portion 145d, so that the holding plate 140 moves clockwise relative to the stopper member 130 in FIGS. It is a wall surface that regulates rotation. Specifically, for example, with a load hung on a lower hook (not shown), the load sheave 20 around which the chain C1 is wound is wound by strongly pulling the loose chain C1 on the side opposite to the lower hook. When the drive shaft 25 and the stopper support member 120 rotate upward and rotate together at high speed via the reduction gear 30, the holding plate 140 also rotates at high speed in accordance with the high speed rotation. At this time, the stopper member 130 moves radially outward due to the centrifugal force, and the stopper projection 131 enters the movement restricting groove portion 145d.

In this state, when the slackness of the chain C1 is eliminated, the rotation of the load sheave 20, the drive shaft 25 and the stopper support member 120 suddenly stops. At this time, even if the holding plate 140 tries to rotate in the winding-up direction due to inertia, the stopper projection 131 abuts against the third restricting wall 145d1, thereby preventing the holding plate 140 from rotating due to inertia.

Therefore, the third restricting wall 145d1 is provided in such a shape that the stopper protrusion 131 does not move to the inner diameter side even when the stopper protrusion 131 presses. As such a shape of the third restricting wall 145d1, for example, the third restricting wall 145d1 may be formed along the radial direction. However, the shape of the third restricting wall 145d1 is not limited to such a shape. It may be formed in a shape that is inclined to the left (counterclockwise side) as it goes in the radial direction.

Similarly to the third regulation wall 145d1, the return guide wall 145d2 is a wall surface on which the stopper projection 131 slides, and prevents the stopper member 130 from engaging with the stopper locking member 110. This is a wall surface for returning to a predetermined storage position on the inner diameter side. Specifically, the return guide wall 145d2 is a wall surface that slopes toward the center in the radial direction toward the right (clockwise direction) in FIGS. 5 to 7 . Therefore, the stopper member 130 can be returned to the storage position of the stopper storage portion 123 using the return guide wall 145d2.

More specifically, the return of the stopper member 130 will be described in detail. In a situation in which the locking projection 143 of the holding plate 140 is in contact with the side surface of the stopper locking member 110 and the stopper member 110 is rotating at a speed higher than a predetermined speed, the centrifugal The force moves the stopper member 130, and the stopper projection 131 moves into the movement restricting groove portion 145d. Consider the case where the rotation of the drive shaft 25 and the stopper support member 120 is decelerated and stopped in this state. Before deceleration, the tension force of the urging spring 151 acts between the stopper supporting member 120 and the holding plate 140, so that the holding plate 140 is the same as the stopper supporting member 120 and the stopper member in FIGS. Although it tries to rotate to the left (counterclockwise direction) with respect to 130 , the rotation is restricted by the contact between the stopper locking member 110 and the locking protrusion 143 . When deceleration is started while rotating at high speed in the wind-up direction, as shown in FIG. It rotates in the winding direction with respect to the member 130 . From this state, the stopper protrusion 131 slides on the return guide wall 145d2 due to the biasing force of the biasing spring 151 while the deceleration is completed and stopped. 130 is pushed back towards the predetermined stowed position. When the magnet M1 slides a predetermined distance and approaches the bottom surface 123b of the stopper housing portion 123, the magnetic force between the magnet M1 and the bottom surface 123b returns the stopper member 130 to the housing position.

In addition, even if the stopper projection 131 is positioned at the outermost radial direction in the movement restricting groove portion 145d, the outer peripheral surface 132 of the stopper member 130 does not protrude further to the outer diameter side than the outer peripheral surface of the stopper support member 120. It is housed in the stopper housing portion 123 . In this state, the stopper supporting member 120, the stopper member 130, and the holding plate 140 can rotate integrally without the stopper member 130 colliding with the locking wall 114. As shown in FIG.

By the way, the stopper member 130, the two holding plates 140, and the biasing unit 150 are assembled to the stopper supporting member 120, and the two holding plates 140 are connected at a predetermined interval by the connecting member R1 (see FIG. 4). By regulating the stopper protrusion 131 with the inner wall of the guide groove 145 and holding the stopper member 130 at a predetermined position in the stopper housing portion 123 of the stopper support member 120, it is possible to form a single unit. By forming a single unit in this way, it is possible to easily and reliably perform operations such as assembly to the drive shaft 25 and removal and replacement during maintenance. In particular, it is possible to check and adjust the operation of the one-unit unit before assembling it to the lever hoist 10 (hoisting machine). Moreover, even when a large load acts on the stopper member 130 , the pair of holding plates 140 can reliably hold the stopper member 130 in the stopper housing portion 123 of the stopper support member 120 .

In addition, in the present embodiment, the connecting member R1 is composed of a rivet and a collar (spacer). That is, a collar is arranged between a pair of holding plates 140, and a rivet is inserted through the hole 141 formed in the holding plate 140 and the collar. After that, by plastically deforming the other end of the rivet, the pair of holding plates 140 are connected while maintaining a predetermined distance.

Next, the biasing unit 150 will be explained. As shown in FIGS. 3 and 4, the biasing unit 150 has a biasing spring 151, a locking pin 152 at one end, and a connecting member R1 corresponding to the locking pin at the other end. Among these, the urging spring 151 is a tension spring in this embodiment. The configuration of the urging unit 150 may include a compression spring or a torsion spring in addition to a tension spring. (lowering direction; first rotation direction).

Also, the one-end locking pin 152 is attached by being inserted into the insertion hole 124 of the stopper support member 120 as described above. The insertion hole 124 is a threaded hole and is attached by screwing the male threaded portion of the locking pin 152 at one end. One end of a biasing spring 161 is hooked on the one end locking pin 152 . Also, the connecting member R1 is also used as the other end locking pin. That is, the other end side of the biasing spring 151 is hooked on the connecting member R1 inserted into the hole 141 .

Here, the point of action of the one-end locking pin 152 where the biasing spring 151 is hooked and the point of action of the connecting member R1 corresponding to the other-end locking pin where the biasing spring 151 is hooked are: It differs from the center of rotation by a predetermined angle θ. Therefore, the biasing spring 151 applies a biasing force so as to reduce the angle θ.

<About action>
Regarding the rotation lock (load drop prevention) device 100 configured as described above, when the lever hoist 10 is hoisted up, the brake device 70 may be damaged, and the drive shaft 25 may be wound by the tension applied to the chain C1 due to the lifting load. Consider when starting an accelerated rotation in the downward direction.

FIG. 8 shows the configuration near the rotation lock (load drop prevention) device 100 in the lever hoist 10 shown in FIG. It is a schematic diagram. FIG. 9 shows the state of each part when the holding plate 140 rotates relative to the stopper supporting member 120 and the holding plate 140 from the state shown in FIG. It is a figure which transparently shows a positional relationship. 10 is a diagram transparently showing the positional relationship of each part in a state in which the stopper member 130 protrudes radially from the state shown in FIG. 9 and the stopper protrusion 131 is positioned in the return restricting groove portion 145c. .

First, when the braking force is lost while the load is suspended, the drive shaft 25 and the stopper support member 120 rapidly rotate in one rotational direction (lowering direction) counterclockwise in FIG. 8 together with the stopper member 130. Increase speed. At this time, the biasing force of the biasing spring 151 pushes the holding plate 140 toward the stopper member in a state where the stopper protrusion 131 of the stopper member 130 is positioned at the extreme end of the gap groove 145b (the end on the side away from the allowance groove 145a). It works to follow the rotation of 130. However, when the inertial force acting on the holding plate 140 exceeds the urging force of the urging spring 151, the holding plate 140 is left behind, and the stopper projection 131 separates from the end of the clearance groove 145b on the side of the movement restricting groove 145d. Further, when the drive shaft 25 accelerates and rotates together with the stopper supporting member 120 and the stopper member 130 with the acceleration in the direction that the stopper protrusion 131 moves away from (cannot follow) the end of the clearance groove 145b on the side of the movement restricting groove 145d, the holding plate 140 is acted upon. The biasing spring 151 is stretched by inertial force, and the stopper projection 131 of the stopper member 130 moves toward the allowance groove portion 145a in the clearance groove portion 145b.

Even if the stopper member 130 attempts to protrude radially outward due to the centrifugal force generated by the rotation of the stopper supporting member 120 and the stopper member 130, the stopper projection 131 does not move until the stopper projection 131 reaches the allowable groove portion 145a. By being restricted by the first restriction wall 145b1, protrusion of the stopper member 130 toward the outer diameter side is restricted.

Then, when the stopper projection 131 relatively moves in the clearance groove portion 145b to the position shown in FIG. 9, the stopper member 130 can protrude to the outer diameter side. That is, the stopper member 130 released from the engagement (holding) state between the stopper projection 131 and the first restricting wall 145b1 protrudes radially outward from the stopper accommodating portion 123 due to the centrifugal force. However, the protrusion to the outer diameter side is within the range up to the outermost peripheral side of the guide groove 145 . On the other hand, even if the rotational acceleration of the drive shaft 25 in the first rotational direction decreases after the stopper member 130 slides in the centrifugal direction from the predetermined position and the stopper projection 131 passes over the projection tip 146a, The biasing force of the biasing spring 151 presses the stopper projection 131 by the second restricting wall 145c1. By this pressing, the stopper member 130 protrudes to a position where it reliably engages with the locking wall 114, and maintains the engagement while the load continues on the drive shaft 25 in the first rotation direction.

When the stopper member 130 protruding from the stopper storage portion 123 continues to rotate in one counterclockwise rotation direction (lowering direction), as shown in FIG. 114 collide. As a result, rotation of the stopper support member 120 and the drive shaft 25 in one of the rotation directions (lowering direction) is stopped, and the load stops falling.

Also, after the stopper member 130 collides with the locking wall 114, the stopper projection 131 enters the return restricting groove portion 145c. As a result, after the drive shaft 25 stops, the biasing force of the biasing spring 151 causes the stopper projection 131 to receive a counterclockwise biasing force from the second restricting wall 145c1. state is maintained. At this time, even if the stopper member 130 inadvertently tries to return to the stopper housing portion 123, the stopper protrusion 131 maintains engagement with the second regulation wall 145c1, so that the stopper member 130 is prevented from returning to the stopper housing portion 123. Regulated. Therefore, the rotation stop state of the drive shaft 25 is maintained. Thus, the load is prevented from starting to fall again.

Next, let us consider the idling mode in which the chain C1 can be manually pulled and pulled out in the lowering direction while the brake device 70 is operating normally. The lever hoist 10 has the idle rotation function so that the length of the chain C1 can be adjusted when the hook is attached to the object. Specifically, it has a function of releasing the brake on the female screw member 35 of the brake device 70 by the action of an idle spring (not shown). In the idling mode, the length of the chain C1 can be adjusted at a faster speed than when the operation lever 50 is operated. In order to switch the lever hoist to the idle rotation mode, there is an automatic idle rotation method in which switching can be performed simply by setting the switching knob 45 to neutral in an unloaded state. is operated to neutral, and then the free rotation setting 60 is further operated in a predetermined manner to switch to the free rotation mode. In the present embodiment, after the latter switching knob 45 is operated to neutral, the idle rotation setting 60 is further operated in a predetermined manner to switch to the idle rotation mode, but detailed description thereof will be omitted. .

In such idle rotation mode, the braking force of the braking device 70 is temporarily disabled. However, for safety reasons, the mechanism is such that the brake device 70 acts to stop the rotation of the drive shaft 25 when a predetermined tension or more is applied to the chain C1 in the lowering direction. On the other hand, the brake device 70 having the pawl wheel 80 adopted in many lever hoists like the lever hoist 10 does not work in the hoisting direction. It is possible to adjust the length of the chain C1 at a faster speed. In the lever hoist 10 in such a situation, workability is improved if the rotation lock (load drop prevention) device 100 does not act in the hoisting direction (the other rotation direction) as much as possible.

By the way, the length adjustment of the chain C1 involves not only letting out the chain C1 in the lowering direction, but also adjusting in the direction of winding up the loose chain C1. As described above, the lowering direction is adjusted by switching to the idle rotation mode, but the braking device 70 is activated when the chain C1 is pulled with a predetermined tension or more. On the other hand, the adjustment in the hoisting direction is performed by the operator pulling the non-load side portion of the chain C1. In this case, the load sheave 20 rotates in the hoisting direction, and the drive shaft 25, the stopper support member 120, and the stopper member 130 also rotate in the hoisting direction. At this time, the inertial force acting on the holding plate 140 acts in a direction to press the stopper protrusion 131 against the end portion of the clearance groove portion 145b on the side of the movement restricting groove portion 145d. In this state, even if the speed at which the chain C1 is pulled in the hoisting direction increases and the centrifugal force acting on the stopper member 130 gradually increases, the stopper protrusion 131 of the stopper member 130 does not move in the clearance groove portion 145b including the movement restricting groove portion 145d. In the positioned state, the stopper member 130 does not engage with the stopper engaging member 110, and the rotation lock by the rotation lock device 100 does not work. Below a predetermined rotation speed, the stopper member 130 does not protrude radially outward due to the magnetic force between the magnet M1 and the bottom surface 123b of the stopper housing portion 123. FIG. Therefore, the stopper projection 131 does not enter the movement restricting groove portion 145d at a rotation speed equal to or lower than the predetermined rotation speed.

However, when the rotational speed exceeds a predetermined value, the centrifugal force acting on the stopper member 130 becomes greater than the holding force due to the magnetic force between the magnet M1 and the bottom surface 123b of the stopper housing portion 123, so that the stopper member 130 moves outward. As it moves, the stopper projection 131 enters the movement restricting groove portion 145d.

In the state shown in FIGS. 11 and 12, the stopper protrusion 131 is located on the outermost diameter side of the movement restricting groove portion 145d and is in contact with the third restricting wall 145d1. In the state shown in FIG. 11, the outer peripheral surface 132 of the stopper member 130 is located at a position equal to or lower than the outer peripheral surface of the stopper support member 120 in the radial direction.

Here, when the slackness of the chain C1 is eliminated, the chain C1 between the load and the lever hoist 10 becomes taut. The rotation of the drive shaft 25 and the stopper support member 120 (stopper member 130) suddenly stops. However, although the holding plate 140 tends to rotate in the winding direction due to inertia, as shown in FIGS. Rotation due to inertia of the holding plate 140 is prevented. In FIG. 11, after the stopper projection 131 enters the movement restricting groove portion 145d, the holding plate 140 rotates slightly in the hoisting direction relative to the state shown in FIG. It is a diagram transparently showing the positional relationship of each part in a state of contact with the.

Therefore, the stopper projection 131 can be prevented from moving toward the allowance groove portion 145a within the clearance groove portion 145b. Therefore, when the stopper protrusion 131 moves toward the outer diameter side within the allowable groove portion 145a, the stopper member 130 protrudes further to the outer diameter side than the outer peripheral surface of the stopper support member 120 even during winding. can be prevented.

Also, when the rotation in the winding direction stops, the stopper member 130 returns to the storage position of the stopper storage portion 123 . That is, the tension force of the biasing spring 151 acts between the stopper support member 120 and the holding plate 140 . Therefore, the stopper supporting member 120 and the stopper member 130 tend to rotate rightward (clockwise) with respect to the holding plate 140 in FIGS. 11 and 12 . Therefore, as shown in FIG. 13, the stopper projection 131 slides along the return guide wall 145d2 under the action of the pulling force of the biasing spring 151. As shown in FIG. When the magnet M1 slides by a predetermined amount and approaches the bottom surface 123b of the stopper housing portion 123, the magnetic force between the magnet M1 and the bottom surface 123b increases, and the stopper member 130 is retracted by the action of the increased magnetic force. return to position.

Even when the stopper member 130 returns to the retracted position, the tension force by the biasing spring 151 continues to act between the stopper support member 120 and the holding plate 140. , the locking projection 143 contacts the side surface of the wide piece 120b of the stopper support member 120. As shown in FIG. Therefore, it is possible to prevent the stopper member 130 from being pressed against the side wall 123a of the stopper support member 120 in a state in which the stopper projection 131 is urged toward the clockwise end portion of the clearance groove portion 145b. Further, since the stopper member 130 is attracted and held by the bottom surface 123b of the stopper housing portion 123 by the magnetic force of the magnet M1, the holding plate rotates in the winding direction with respect to the stopper supporting member, and the stopper projection 131 is positioned in the allowable groove portion 145a. Even so, the stopper member 130 is accommodated at a predetermined position in the stopper accommodating portion and the rotation lock by the rotation lock device 100 does not work unless a force exceeding the attractive force of the magnetic force acts.

Next, consider the case where the operator pulls the chain C1 in the lowering direction. At this time, the load sheave 20 rotates in the lowering direction, and the drive shaft 25, the stopper support member 120, and the stopper member 130 also rotate in the lowering direction. At this time, the rotational acceleration of the stopper supporting member 120 and the stopper member 130 causes the holding plate 140 to rotate against the biasing force of the biasing spring 151 so that it is left behind, and the stopper projection 131 moves toward the end of the clearance groove 145b. (the end on the side away from the allowable groove portion 145a). In this case, if the length of the clearance groove portion 145b is short, the stopper projection 131 relatively easily reaches the allowance groove portion 145a, and then the stopper member 130 protrudes to the outer diameter side to form the locking wall 114 and the stopper member 130. will result in a conflicting lock state. In this case, the work of pulling the chain C1 in the lowering direction by the operator is interrupted, and it is necessary to release the locked state, which deteriorates workability.

However, in this embodiment, the length of the clearance groove portion 145b is sufficiently longer than the above-mentioned angle γ, and the stopper projection 131 does not move when the operator pulls the chain C1 in the lowering direction. It is set to such an extent that it cannot reach the allowable groove portion 145a even if it moves slightly within the clearance groove portion 145b. Therefore, the work of pulling the chain C1 in the lowering direction by the operator is not interrupted. When the drive shaft 25 rapidly rotates in the lowering direction in the idle rotation mode, the brake device 70 temporarily released in the idle rotation mode brakes the rotation of the drive shaft 25 before the rotation lock device 100. The length of the clearance groove portion 145b is set.

<About effect>
The rotation lock (load drop prevention) device 100 configured as described above includes a stopper support member 120 that is attached to the drive shaft 25 (shaft-shaped member) and rotates integrally with the drive shaft 25 (shaft-shaped member); A stopper member 130 supported by a stopper support member 120 in a slidable state outwardly from the axial center side of the shaft 25 (shaft-like member); a holding plate 140 which is rotatably provided to hold the stopper member 130 at a predetermined position of the stopper supporting member 120; A biasing spring 151 (biasing means) that biases toward the stopper member 130 and a stopper locking member 110 (stopper locking means) that stops the rotation of the drive shaft 25 (shaft-shaped member) by engaging with the stopper member 130 . , is equipped with The stopper member 130 has a stopper projection 131 projecting toward the holding plate 140 , and the holding plate 140 engages with the stopper projection 131 to hold the stopper member 130 at a predetermined position in the radial direction of the stopper support member 120 . The guide groove 145 engages with the stopper member 130 at a predetermined position in the radial direction and is formed with a circular arc concentric with the drive shaft 25 (shaft-like member). , and a second restricting wall 145c1 that engages at a position where the stopper member 130 protrudes radially outward from a predetermined position in the radial direction. is provided.

Further, when the drive shaft 25 (shaft-like member) accelerates its rotation in the first rotation direction, the stopper supporting member 120 and the holding plate 140 are pushed against the biasing force of the biasing spring 151 (biasing means). When the stopper projection 131 rotates relatively and is disengaged from the first regulation wall 145b1, the stopper member 130 engages with the stopper locking member 110 (stopper locking means) from a predetermined position. and stops the rotation of the drive shaft 25 (shaft-shaped member). Along with this, on the other side of the guide groove 145 in the circumferential direction, the stopper member 130 is engaged with the stopper member 130 at a position protruding radially outward from a predetermined position in the radial direction, thereby rotating in the direction opposite to the first rotation direction. A third restriction wall 145d1 is provided to prevent the holding plate 140 from rotating relative to the stopper support member 120 in the second rotation direction. Then, when the stopper projection 131 is engaged with the third restricting wall 145d1, the stopper member 130 and the stopper locking member 110 (stopper locking means) are positioned at a non-locking position.

According to such a configuration, the operator pulls the loose chain C1 in the winding direction at high speed, and the centrifugal force acting on the stopper member 130 causes the stopper member 130 to protrude toward the outer diameter side, causing the chain C1 to loosen. is released and the rotation of the drive shaft 25 and stopper supporting member 120 (stopper member 130) suddenly stops, the holding plate 140 tends to rotate in the winding direction due to inertia. However, when the stopper projection 131 abuts (collides) with the third restricting wall 145d1, the rotation of the holding plate 140 due to inertia is prevented. Therefore, the stopper projection 131 can be prevented from moving in the guide groove 145 in the second rotation direction. Further, when the stopper projection 131 is engaged with the third regulating wall 145d1, the stopper member 130 and the stopper locking member 110 (stopper locking means) are positioned at a position where they are not locked. First, it is possible to prevent the stopper member 130 from protruding radially outward beyond the outer peripheral surface of the stopper support member 120 .

Therefore, the rotation lock device 100 is unintentionally operated even though the load is not actually dropped (the operation is in the hoisting direction), and the drive shaft 25 (shaft-like member) rotates. It is possible to prevent the rotation lock device 100 from becoming disabled, thereby preventing the trouble of restoring the rotation lock device 100 .

In addition, when the drive shaft 25 (shaft-shaped member) exceeds a predetermined acceleration in one rotation direction in the lowering direction, the rotation lock (load drop prevention) device 100 is activated to stop the rotation. Furthermore, when the drive shaft 25 (shaft-shaped member) rotates in the first rotation direction, which is one rotation direction, the synergistic effect of the acceleration and the rotation speed causes rotation in the other rotation direction. It is possible to set the rotation lock (load drop prevention) device 100 to operate at a lower speed. In addition, even if the brake device 70 fails in a driving device such as a hoist or a lifting device in which a load acts only in one direction, the rotation of the rotating member for hoisting or lifting is immediately stopped, and the load is dropped. It is possible to prevent accidents caused by

In the present embodiment, a return guide wall 145d2 for returning the stopper member 130 to a predetermined position on the axial side is provided on the other side of the third regulation wall 145d1 in the circumferential direction. The wall 145d2 is inclined toward the inner diameter side from one side in the circumferential direction to the other side.

With such a configuration, it becomes easy to return the stopper member 130 to the predetermined position (storage position) of the stopper support member 120 . That is, the tension force of the biasing spring 151 (biasing means) acts between the stopper supporting member 120 and the holding plate 140 . Therefore, the stopper supporting member 120 and the stopper member 130 tend to rotate rightward (clockwise) with respect to the holding plate 140 in FIGS. By sliding along, the stopper member 130 can be moved toward a predetermined position (storage position) of the stopper support member 120 . Therefore, it becomes easy to return the stopper member 130 to the predetermined position (storage position) of the stopper support member 120 .

Further, in the present embodiment, the third restricting wall 145d1 and the return guide wall 145d2 are provided on the inner wall of the movement restricting groove portion 145d. Therefore, when the holding plate 140 is processed, the third restricting wall 145d1 and the return guide wall 145d2 can be formed at the same time by, for example, pressing, thereby simplifying the processing steps.

In addition, in the present embodiment, the stopper support member 120 is made of a soft magnetic material, and the magnet M1 is attached to the inner diameter side of the stopper member 130 in the radial direction. Therefore, the magnetic force of the magnet M1 can assist the stopper member 130 to return to the predetermined position (storage position).

In the present embodiment, retaining plate 140 is provided with locking projection 143 (projecting means) projecting from the front surface or the back surface of holding plate 140, and locking projection 143 (projecting means) ), when the holding plate 140 is urged in the first rotational direction by the urging spring 151 (urging means), the stopper projection 131 is positioned at the end of the guide groove 145 opposite to the first rotational direction. 120 b 1 of the stopper support member 120 before or at the same time as it contacts the stopper support member 120 .

Therefore, when the locking protrusion 143 (protruding means) abuts against the side surface 120b1 of the stopper support member 120, it is possible to prevent the urging force from continuing to act on the stopper protrusion 131. FIG. In addition, it is possible to prevent the stopper member 130 from being pressed against the side wall inside the stopper housing portion 123 . Therefore, it is possible to prevent the stopper member 130 from being hindered from returning to the predetermined position (storage position) due to the frictional force between the stopper member 130 and the inner side wall of the stopper housing portion 123 .

Further, in the present embodiment, the holding plate 140 is formed by bending a part of the holding plate 140, and is arranged on the outer diameter side of the holding plate 140 from the biasing spring 151 (biasing means). A spring receiving protrusion 144 is provided, and the spring receiving protrusion 144 receives the dropping of the biasing spring 151 (biasing means) toward the outer diameter side due to the centrifugal force when the holding plate 140 rotates.

Since the spring receiving projection 144 is arranged on the outer diameter side of the holding plate 140B relative to the biasing spring 151 (biasing means), the biasing spring 151 is moved by centrifugal force when the holding plate 140 rotates. Dropping toward the outer diameter side can be received.

<Modification>
Although each embodiment of the present invention has been described above, the present invention can be variously modified. This will be discussed below.

In each of the above-described embodiments, a case where the rotation lock (load drop prevention) device 100 is applied to the lever hoist 10 has been described. However, the above-described rotation lock (load drop prevention) device is not applicable to hoisting machines other than lever hoists, such as chain blocks, or lifting devices in which the direction of load is constant like hoisting devices. can be

Also, in the above embodiment, the case where the magnet M1 is attached to the bottom surface 130a of the stopper member 130 is described. However, the magnet may be attached to the bottom surface 123b of the stopper housing portion 123, or may be attached to both the bottom surface 130a of the stopper member 130 and the bottom surface 123b of the stopper housing portion 123. FIG.

An example of such a configuration is shown in FIG. In FIG. 14, a concave portion (reference numerals omitted) is provided on the side of the bottom surface 130a of the stopper member 130, and the magnet M1 is arranged in the concave portion. In addition, a concave portion (reference numeral omitted) is also provided on the bottom surface 123b side of the stopper support member 120, and the magnet M2 is arranged in the concave portion. At this time, the magnetic poles of the magnets M1 and M2 facing each other are different so that the magnets M1 and M2 are attracted by magnetic force.

Here, when the magnets M1 and M2 are in contact with each other and attracted as shown in FIG. is equivalent to the attraction force when the bottom surface 123b of the stopper support member 120 made of iron-based metal is in contact with and attracted to the bottom surface 123b (that is, when the distance between the magnet M1 and the bottom surface 123b is 0). ing.

Here, as shown in FIG. 15A, when the magnet M1 and the bottom surface 123b of the stopper support member 120 face each other with a distance Y, the magnet M1 and M2 are separated from each other by the same distance Y. and the attraction force in the case of facing each other. In this case, the attractive force of the magnet is inversely proportional to the square of the distance. When M2 faces the same distance Y, the attractive force is about four times. In other words, as shown in FIG. 15(A), the attraction force when the magnet M1 and the bottom surface 123b of the stopper support member 120 face each other with a distance Y is shown in FIG. 15(B). This is when the magnet M1 and the bottom surface 123b of the stopper support member 120 face each other with a distance Y/2 apart.

In this way, the magnets M1 and M2 that exert magnetic forces in mutually attracting directions are attached to both the radially inner diameter side of the stopper member 130 and the opposing portion of the stopper support member 120, respectively. Therefore, compared to the configuration shown in FIG. 5 in which the magnet M1 and the bottom surface 123b of the stopper support member 120 are opposed to each other, the magnetic attraction force acting when the magnets M1 and M2 are separated from each other is reduced. To easily return the stopper member 130 to a predetermined position (storage position) even if a certain degree of frictional resistance is generated by foreign matter when the stopper member 130 protrudes to the outer diameter side. can be done.

As is clear from FIGS. 6 and 7, etc., in the holding plate 140, the radial dimension of the movement restricting groove portion 145d is smaller than that of the allowable groove portion 145a. Therefore, when the stopper member 130 is positioned in the allowable groove portion 145a, compared to the case where the stopper member 130 is positioned in the movement restricting groove portion 145d, the stopper member 130 protrudes radially toward the outer diameter side. becomes smaller. Therefore, when adopting the configuration in which the magnets M1 and M2 are arranged as described above, compared to the configuration in which the magnet M1 and the bottom surface 123b of the stopper support member 120 face each other, the stopper member 130 is positioned at a predetermined position. It can be easily returned to the (storage position).

Further, although the rotation lock (load drop prevention) device 100 is exemplified as being arranged on the drive shaft of the hoist, its mounting position is not limited to the drive shaft. A rotation lock (load drop prevention) device 100 can be arranged on a shaft-like member that rotates integrally with a target rotating member, such as a part. By doing so, even if the speed reduction mechanism or the like is damaged, the load can be prevented from falling.

Although not shown, a guide groove may be provided on the stopper member 130 side, and a guide pin that engages with the guide groove may be provided on the holding plate 140 side.

In addition, although it is preferable that two holding plates 140 are arranged so as to sandwich the stopper supporting member 120 , only one holding plate 140 may be arranged adjacent to the stopper supporting member 120 .

Further, the rotation of the holding plate 140 by the urging force of the urging unit 160 is prevented by bending a part of the holding plate 140B to provide a locking projection 143 corresponding to the projecting means, which abuts against the side surface 120b1 of the stopper support member 120. I try to regulate it by coming into contact with it. However, another member attached to the holding plate 140, such as a connecting member R1 such as a rivet, may be used as the protruding means.

The magnet M1 is provided to pull the stopper member 130 back to the position where it contacts the bottom surface 123b when the stopper projection 131 is positioned in the movement restricting groove 145d. It may be pulled back by the biasing force of the biasing unit 160 .

Also, the movement restricting groove portion 145d having the third restricting wall 145d1 is provided at the other end portion of the clearance groove portion, but it may be disposed not only at the end portion but also at the intermediate portion, or a plurality of such portions may be provided.

DESCRIPTION OF SYMBOLS 10... Lever hoist 11, 12... Frame 12a... Through hole 12b... Shaft hole 13... Casing 14... Brake cover 14a... Flange part 14a1... Insertion hole 15... Lock cover 15a... Standing part, 15b... facing surface 15b1... through hole 20... load sheave 20a... insertion hole 21... load gear 25... driving shaft (corresponding to shaft-like member) 26... male threaded portion 27... pinion gear 30... reduction gear , 31 large-diameter gear portion 32 small-diameter gear portion 34 gear box 35 female screw member 36 female screw portion 37 switching gear 40 switching pawl 45 switching knob 50 operation lever 55... Cam member 60... Idle grip 70... Brake device 71... Brake receiver 71a... Flange part 71b...

Hollow boss part

72a, 72b... Brake plate 80... Ratchet wheel (part of ratchet mechanism corresponding), 83... Ratchet teeth, 90... Pawl member (corresponding to part of the ratchet mechanism), 91... Pawl shaft, 92... Bush, 93... Torsion spring, 93a... Coil portion, 100... Rotation lock (load drop prevention) Apparatus 110 Stopper locking member (corresponding to stopper locking means) 111 Mounting hole 111a Inner wall surface 112 Inner protrusion 113 Concave portion 114 Locking wall 114a Corner 115 116 Rib 120 Stopper support member 120a Narrow piece 120b Wide piece 121 Center hole 122 Bearing boss 123 Stopper Storage part 123a Side wall 123b Bottom 124 Insertion hole 125 Storage recess 126 Retaining recess 127 Inclined wall 130 Stopper member 130a Bottom 131 Stopper projection 132 Outer periphery Surface 140... Holding plate 141... Hole 142... Center hole 143... Engagement protrusion 144... Spring receiving protrusion 145... Guide groove 145a... Allowable groove 145a1... Inner wall 145b... Space Grooves 145b1 First restricting wall 145c Return restricting groove 145c1 Second restricting wall 146 Holding projection 146a Tip of projection 150 Biasing unit (corresponding to biasing means) 151 Biasing spring 152... One end locking pin B1... Stay bolt (corresponding to fastening member) C1... Chain R1... Connecting member SP1... Space

Claims

a stopper support member that is attached to the shaft-shaped member and rotates integrally with the shaft-shaped member;
a stopper member supported by the stopper support member in a slidable state from the axial center side of the shaft-shaped member toward the outer side;
a holding plate provided in the shape of a disk and rotatable relative to the stopper support member for holding the stopper member at a predetermined position on the stopper support member;
urging means for urging the holding plate toward the stopper support member in a first rotation direction, which is one rotation direction;
stopper locking means for stopping rotation of the shaft member by engaging with the stopper member;
with
The stopper member has a stopper projection projecting toward the holding plate,
The holding plate has a guide groove that engages with the stopper projection and holds the stopper member at a predetermined position in the radial direction of the stopper support member,
The guide groove includes a first restricting wall formed by an arc concentric with the shaft-like member and with which the stopper member engages at a predetermined position in the radial direction, and a second restricting wall that engages at a position where the stopper member protrudes,
The second regulation wall is provided on one side of the guide groove in the circumferential direction,
When the shaft-like member accelerates its rotation in the first rotation direction, the stopper supporting member and the holding plate rotate relatively against the biasing force of the biasing means, and the stopper protrusion is moved. When the stopper member is disengaged from the first regulating wall, the stopper member protrudes from a predetermined position to a position where it engages with the stopper locking means, thereby stopping the rotation of the shaft-like member,
On the other side of the guide groove in the circumferential direction, the stopper member engages with the stopper member at a position where the stopper member protrudes radially outwardly from a predetermined position in the radial direction, thereby rotating in the direction opposite to the first rotation direction. a third regulating wall that prevents the holding plate from rotating relative to the stopper support member in a second rotation direction;
When the stopper protrusion is engaged with the third regulating wall, the stopper member and the stopper locking means are positioned at a non-locking portion,
A rotation lock device characterized by:
The rotation lock device of claim 1, wherein
A return guide wall for returning the stopper member to a predetermined position on the axial center side is provided on the other side of the third regulation wall in the circumferential direction,
The return guide wall is inclined toward the inner diameter side from one side in the circumferential direction toward the other side.
A rotation lock device characterized by:
3. The rotation lock device of claim 2, wherein
The third restricting wall and the return guide wall are provided on the inner wall of the movement restricting groove,
A rotation lock device characterized by:
The rotation lock device according to any one of claims 1 to 3,
The stopper supporting member is made of a soft magnetic material, and
A magnet that exerts a magnetic force in a mutually attracting direction is attached to at least one of a portion of the stopper member facing the inner diameter side in the radial direction and the stopper support member,
A rotation lock device characterized by:
5. The rotation lock device of claim 4,
Magnets that exert a magnetic force in a mutually attracting direction are attached to both the radially inner diameter side of the stopper member and the opposed portion of the stopper supporting member, respectively.
A rotation lock device characterized by:
The rotation lock device according to any one of claims 1 to 5,
The holding plate is provided with protruding means protruding from the front surface or the back surface of the holding plate,
The protruding means is such that when the holding plate is urged in the first rotational direction by the urging means, the stopper projection is positioned at the end of the guide groove opposite to the first rotational direction. It is arranged at a position where it abuts against the side surface of the stopper support member before or at the same time as it abuts,
A rotation lock device characterized by:
The rotation lock device according to any one of claims 1 to 6,
The holding plate is provided with a spring receiving protrusion that is formed by bending a part of the holding plate and that is arranged on the outer diameter side of the holding plate relative to the biasing means,
The spring receiving projection receives the urging means from falling off to the outer diameter side due to centrifugal force generated when the holding plate rotates.
A rotation lock device characterized by:
A load sheave that is pivotally supported by a pair of frames and has a chain for lifting a load wrapped around it;
a drive shaft coupled to the load sheave via a reduction gear;
a brake device attached to the drive shaft;
A hoisting machine comprising an operation lever for rotationally driving and operating the load sheave in hoisting and hoisting directions,
The rotation lock device according to any one of claims 1 to 6 is arranged on the outer periphery of the drive shaft,
The shaft-shaped member is the drive shaft,
the stopper locking means is attached to the frame;
A hoist characterized by: