Rotary locking device, lever hoist and winch

Abstract

The present invention provides a winch that can reliably stop the rotation of a shaft member when the braking device malfunctions, and can improve the installation strength of the pawl shaft; the winch (10) includes a rotation locking device (100) for locking the rotation of the shaft member (25), the rotation locking device (100) including: a limiting member support member (120) that rotates integrally with the shaft member (25), a limiting member (140) that is slidably supported on the limiting member support member (120), and a limiting member... The locking mechanism (110) has a locking wall (114) that stops the rotation of the shaft member (25) by abutting against the limiting member (140); when the shaft member (25) accelerates in the first rotation direction, the limiting member (140) protrudes to the position of engaging with the locking mechanism (110) to stop the rotation of the shaft member (25); and a pawl shaft (115) is integrally formed on each locking mechanism (110), and the locking mechanism (110) is mounted on the frame (12) by a support bolt (B1).

Description

Technical Field

[0001] This invention relates to a rotation lock device, a lever hoist, and a winch. Background Technology

[0002] Hand lever hoists are widely used for lifting, pulling, and securing goods using slings or similar means. By manually operating the lever, the chain can be wound up and unwound. One type of hand lever hoist is shown in Patent Document 1. In the hand lever hoist shown in Patent Document 1, in addition to the previously existing braking mechanism (mechanical brake), two centrifugal force members (31) and an outer housing ring (35) for housing the centrifugal force members (31) are provided on the side closer to the operating handle (12) than the pinion frame (2B). The centrifugal force members (31) are pressed against the inner circumference of the outer housing ring (35) by centrifugal force. This reduces the speed at which the goods fall.

[0003] Furthermore, the aforementioned braking mechanism (mechanical brake) is configured, for example, as shown in Patent Document 2. This braking mechanism includes: a pair of brake plates (10a, 10b), an anti-reverse ratchet (11), and a pawl (12) mounted on the pawl shaft (15). Moreover, by applying force to the pawl (12) via a spring (13), the pawl (12) engages with the locking teeth (11a) of the ratchet (11). This engagement prevents the ratchet (11) from reversing, thereby allowing the drive shaft (4) to rotate only in one direction, namely the winding direction.

[0004] [Existing Technical Documents]

[0005] [Patent Documents]

[0006] Patent Document 1: German Patent, DE102015121581A1

[0007] Patent Document 2: Japanese Patent Application Publication No. 2008-230726 Summary of the Invention

[0008] (The problem that the invention aims to solve)

[0009] However, during the winding operation of hoists (lever hoists or chain hoists), in braking mechanisms (mechanical brakes) equipped with ratchet mechanisms, for example, when there is poor engagement or damage between the locking teeth (11a) and the pawl (12) of the ratchet (11), as shown in Patent Document 2, the mechanism may fail to function. This ratchet mechanism includes a ratchet with multiple teeth formed on its outer periphery and a pawl member that engages with these teeth. When the brake fails to function, the following may occur: due to the load of the suspended cargo, the load pulley wound around the chain begins to rotate violently in the winding direction, causing the cargo to fall.

[0010] In the event of a malfunction in the braking mechanism, in the structure disclosed in Patent Document 1, the centrifugal force member (31) is pressed against the inner circumferential surface of the outer bushing (35) by utilizing centrifugal force, thereby slowing down the falling speed of the goods (i.e., the rotational speed of the pinion). However, it is not possible to stop the falling of the goods.

[0011] Furthermore, in the structure shown in Patent Document 2, the pawl shaft (15) is installed on the frame (1b) by pressing or other methods. However, since the frame (1b) is relatively thin, if the length of the pawl shaft (15) increases, the torque acting on the pawl shaft (15) also increases. Therefore, it is necessary to correspondingly improve the strength of the pawl shaft (15) and its mounting part. However, when the pawl shaft (15) is installed in the hole of the frame (1b) by pressing, there are limitations to the improvement of its mounting strength.

[0012] The present invention was made in view of the above circumstances, and its object is to provide a rotary locking device, a lever hoist, and a winch that can reliably stop the rotation of a shaft-shaped member in the event of a brake device failure or other similar situations, and can improve the installation strength of the pawl shaft.

[0013] (A solution to the problem)

[0014] To address the aforementioned issues, according to a first aspect of the present invention, a rotary locking device is provided, which has the following features.

[0015] The rotation locking device comprises: a limiting member support member mounted on and rotating integrally with the shaft-shaped member; a limiting member supported on the limiting member support member in a state capable of sliding outward from the axial side of the shaft-shaped member; a retaining mechanism holding the limiting member in a predetermined position on the limiting member support member; a force-applying mechanism applying a force to the retaining mechanism in a first rotational direction relative to the limiting member; and a limiting member locking mechanism stopping the rotation of the shaft-shaped member by engaging with the limiting member. When the shaft-shaped member accelerates its rotation in the first rotational direction, the retaining force of the retaining mechanism on the limiting member is reduced and / or released by the inertial load of the retaining mechanism, thereby causing the limiting member to protrude from the predetermined position toward the position engaged with the limiting member locking mechanism, and stopping the rotation of the shaft-shaped member.

[0016] In addition, in the above invention, it is preferable that the retaining mechanism has a circular retaining plate and a retaining pin; the retaining plate has a bearing hole that is axially supported and can rotate about the axis of the shaft member, and the limiting member support member and the retaining plate are connected by a force-applying mechanism.

[0017] Furthermore, in the above invention, it is preferable that a retaining recess is provided on the side of the limiting member opposite to the side of the first rotation direction, which engages with the retaining pin.

[0018] Furthermore, in the above invention, it is preferable that the limiting member locking mechanism has: an insertion hole that allows the limiting member support member to rotate freely about the axis of the shaft member; a locking recess that is recessed from the inner wall of the insertion hole to the outer diameter side and allows the limiting member protruding from the outer periphery of the limiting member support member to enter; and a locking wall that is provided at the end side of the locking recess in the first rotation direction and stops the rotation of the shaft member by abutting against the limiting member.

[0019] Furthermore, in the above invention, it is preferable that the limiting member locking mechanism has a locking release wall that gradually protrudes toward the axis as it moves toward the end side of the locking recess in the second rotation direction, which is opposite to the first rotation direction; and that the shaft-shaped member is rotated in the second rotation direction while the locking release wall is in contact with the limiting member, thereby pushing the limiting member back from the protruding position.

[0020] Furthermore, in the above invention, it is preferable that: the retaining mechanism has a circular retaining plate; the retaining plate has a bearing hole supported by a shaft so as to be rotatable about the axis of the shaft-shaped member; the limiting member support member and the retaining plate are connected by a force-applying mechanism; the limiting member has a limiting protrusion protruding toward the retaining plate; the retaining plate has a retaining protrusion that engages with the limiting protrusion and holds the limiting member at a predetermined position in the radial direction of the limiting member support member; the retaining protrusion has: a first limiting wall that engages with the limiting member at the predetermined position in the radial direction, and a second limiting wall that engages with the limiting member at a position protruding from the predetermined position in the radial direction toward the outer diameter side.

[0021] Furthermore, in the above invention, it is preferable that: when the shaft-shaped member accelerates its rotation in the first rotation direction, the holding mechanism resists the force of the force-applying mechanism and rotates relative to the shaft-shaped member in a direction opposite to the first rotation direction; the holding mechanism holds the limiting member at a predetermined position in the radial direction until the angle of the relative rotation exceeds the predetermined angle.

[0022] Furthermore, in the above invention, it is preferable that the shaft-shaped member and the load pulley around which the chain is wound are integrally connected.

[0023] Furthermore, to address the aforementioned issues, according to a second aspect of the present invention, a lever hoist is provided, comprising: a load pulley supported by a pair of frame shafts and around which a chain for lifting goods is wound; a drive shaft connected to the load pulley via a reduction gear; a braking device mounted on the drive shaft; and an operating lever, by operating the lever, driving the load pulley to rotate in the winding and rewinding direction. The lever hoist is characterized in that: a rotation locking device as described in the aforementioned inventions is disposed on the outer periphery of the drive shaft; the shaft-like member is the drive shaft; and a limiting member locking mechanism is mounted on the frame.

[0024] Furthermore, in the above invention, it is preferable that: in the rotary locking device, when the shaft-shaped member accelerates its rotation in the first rotation direction, the holding mechanism resists the force of the force-applying mechanism and rotates relative to the shaft-shaped member in the opposite direction to the first rotation direction, and the holding mechanism holds the limiting member at a predetermined position in the radial direction until the angle of the relative rotation exceeds a predetermined angle; the braking device includes a ratchet with a plurality of ratchet teeth; the drive shaft includes a rotary locking device; the predetermined angle is the angle obtained by dividing one revolution of the ratchet by the number of ratchet teeth.

[0025] In addition, to solve the above-mentioned problems, according to a third aspect of the present invention, a winch having a plate-shaped frame is provided.

[0026] The winch has the following characteristics.

[0027] The device includes a braking device and a rotation locking device. The braking device has a ratchet mechanism comprising: a ratchet mounted around the shaft-like member and having ratchet teeth on its outer periphery; a pawl member engaging with the ratchet teeth; and a pawl shaft that supports the rotation of the pawl member. The engagement of the ratchet teeth with the pawl member allows the ratchet to rotate in the coiling direction but prevents rotation in the winding direction. The rotation locking device locks the shaft-like member from rapid rotation. The rotation locking device includes: a limiting member supporting the shaft-like member, which is mounted on and rotates integrally with the shaft-like member; and a limiting member that allows movement from the shaft-like member... The shaft-shaped member is supported by a limiting member support member in a state where its axial side slides outward; a retaining mechanism holds the limiting member in a predetermined position on the limiting member support member; a force-applying mechanism applies a force to the retaining mechanism so that it is oriented in the winding direction relative to the limiting member; and a limiting member locking mechanism stops the rotation of the shaft-shaped member by abutting against the limiting member; when the shaft-shaped member accelerates its rotation in the winding direction, the retaining force of the retaining mechanism on the limiting member is released by the inertial load of the retaining mechanism, thereby causing the limiting member to protrude from the predetermined position to the position engaged with the limiting member locking mechanism, and stopping the rotation of the shaft-shaped member.

[0028] Furthermore, in the above invention, it is preferable that a ratchet shaft is integrally formed on each limiting member locking mechanism; the limiting member locking mechanism is mounted on the frame using fastening members.

[0029] Furthermore, in the above invention, it is preferable that a pair of limiting member locking mechanisms are provided at different positions in the circumferential direction of the shaft member, and a space is provided between one limiting member locking mechanism and the other limiting member locking mechanism.

[0030] Furthermore, in the above invention, preferably: the retaining mechanism has a circular retaining plate; the retaining plate has a bearing hole supported by a shaft so as to be rotatable about the axis of the shaft-like member; the limiting member support member and the retaining plate are connected by a force-applying mechanism; the limiting member has a limiting protrusion protruding toward the retaining plate; the retaining plate has a guide groove that engages with the limiting protrusion and holds the limiting member at a predetermined position in the radial direction of the limiting member support member; the guide groove has: a first limiting wall that engages with the limiting member at the predetermined position in the radial direction, and a second limiting wall that engages with the limiting member at a position protruding from the predetermined position in the radial direction toward the outer diameter side; the first limiting wall is formed by an arc concentric with the bearing hole.

[0031] Furthermore, in the above invention, it is preferable that a clearance groove extending in the circumferential direction is formed on the retaining plate, the limiting protrusion can move along the clearance groove, and the first limiting wall is the outer diameter side wall surface of the clearance groove.

[0032] Furthermore, in the above invention, it is preferable that: a concave limiting member receiving portion is provided on the limiting member support member to receive the limiting member, and the limiting member is received in the limiting member receiving portion when it does not protrude to the outer diameter side; an arc-shaped bottom surface is provided on the inner side of the limiting member receiving portion, which is the inner diameter side of the shaft-shaped member, and an arc-shaped side surface of the limiting member that engages with the limiting member receiving portion is provided on the inner diameter side of the shaft-shaped member.

[0033] Furthermore, in the above invention, it is preferable that: when the shaft-shaped member accelerates its rotation in the first rotation direction, the holding mechanism resists the force of the force-applying mechanism and rotates relative to the shaft-shaped member in a direction opposite to the first rotation direction; the holding mechanism holds the limiting member at a predetermined position in the radial direction until the angle of the relative rotation exceeds the predetermined angle.

[0034] Furthermore, in the above invention, it is preferable that the winch is a lever hoist, which has: a load pulley supported by a pair of frame shafts and around which a chain for lifting goods is wound, a drive shaft connected to the load pulley via a reduction gear and corresponding to a shaft-like member, and an operating lever, by operating the lever, driving the load pulley to rotate in the winding and rewinding direction.

[0035] (Invention Effects)

[0036] According to the present invention, a winch is provided that can reliably stop the rotation of the shaft member in the event of a brake device malfunction or the like, and can improve the installation strength of the pawl shaft. Attached Figure Description

[0037] Figure 1 This is a front view showing an example structure of a lever hoist equipped with the rotary locking (cargo drop prevention) device according to the first embodiment of the present invention.

[0038] Figure 2 It means Figure 1 The diagram shows a cross-sectional view of the structure of a lever hoist.

[0039] Figure 3 It is Figure 1 The diagram shows a partial cross-sectional view of the through hole for inserting the support bolt in the lever hoist shown, and the structure near the through hole.

[0040] Figure 4 It means Figure 1 A cross-sectional view of the structure near the rotary locking (cargo falling prevention) device in the lever hoist shown.

[0041] Figure 5 It means Figure 3 An exploded perspective view of the structure of the rotary locking (cargo falling prevention) device shown.

[0042] Figure 6 It means Figure 1 A top view of the structure of the retaining plate in the lever hoist shown.

[0043] Figure 7 It means Figure 1 The diagram shows the structure near the rotary locking (cargo drop prevention) device in the lever hoist, and is a perspective view showing the positional relationship of the various parts before the rotary locking (cargo drop prevention) device is in operation.

[0044] Figure 8 It is a perspective representation from Figure 7 The diagram shows the positional relationship of various parts in the state where the limiting member support and the retaining plate rotate relative to each other and the limiting protrusion reaches the allowable groove.

[0045] Figure 9 It is a perspective representation from Figure 8 The diagram shows the positional relationship of various parts in the state where the limiting member protrudes to the outer diameter side and the limiting protrusion is located in the state of returning to the limiting groove.

[0046] Figure 10 Involving Figure 1 The modified example of the lever hoist shown is a diagram illustrating the structure near the rotary locking (cargo drop prevention) device, and a perspective view showing the positional relationship of the various parts before the rotary locking (cargo drop prevention) device is activated.

[0047] Figure 11 This is a cross-sectional view showing the structure near the rotation locking (cargo falling prevention) device according to the second embodiment of the present invention.

[0048] Figure 12 It means Figure 11 An exploded perspective view of the structure of the rotary locking (cargo falling prevention) device shown.

[0049] Figure 13 This indicates the structure of a rotary locking (cargo drop prevention) device and is derived from... Figure 12 A decomposed 3D diagram showing the state when viewed from different angles.

[0050] Figure 14 It means in Figure 11 The cross-section of the device shown is a cross-sectional view of the rotating locking (cargo falling prevention) device after it has been activated.

[0051] Figure 15 yes Figure 14 An enlarged schematic diagram of the area near the movement-limiting component.

[0052] Figure 16 yes Figure 11 An enlarged schematic diagram of the area near the movement-limiting component.

[0053] Figure 17 This is a cross-sectional view showing the schematic structure of a rotary locking device according to a modified example of the present invention.

[0054] Figure 18 This is a cross-sectional view showing the schematic structure of a rotary locking device according to another variation of the present invention.

[0055] Figure 19 A variation of the invention is shown in a diagram illustrating another engagement method of the retaining pin and the limiting member.

[0056] Figure 20 It means from Figure 19 The diagram shows the state after the limiting component protrudes and engages with the locking wall.

[0057] Figure 21 This is the front view representing a variation of the retaining mechanism.

[0058] Figure 22 yes Figure 21 The side sectional view of the retaining mechanism shown.

[0059] Figure 23 Another variation of the invention shows an inclined wall provided near the opening of the limiting member storage section, and the guide groove is shown in perspective. Detailed Implementation

[0060] [First Implementation]

[0061] The lever hoist 10 of the first embodiment of the present invention will now be described with reference to the accompanying drawings. In the following description, the X direction is defined as the axial direction of the drive shaft 25, the X1 side is defined as the side on which the idler handle 60 is mounted, and the X2 side is the gearbox 34 side opposite to it. Furthermore, the Z direction is defined as the vertical direction (suspension direction; winding or rewinding direction) of the lever hoist 10 in its suspended state, the Z1 side is defined as the upper side in the suspended state, and the Z2 side is defined as the lower side in the suspended state. Additionally, the direction perpendicular to the X and Z directions is defined as the Y direction, and the Y1 side is... Figure 4 and Figure 5 The middle is on the right side, and the Y2 side is on the right side. Figure 4 and Figure 5 The left side is shown in the middle. Furthermore, in the following description, regarding the rotation direction of the load sheave 20, the winding direction is defined as one rotation direction, and the coiling direction as another. Additionally, the rotation direction around the shaft connected to the load sheave 20 is based on the direction in which the load sheave 20 rotates.

[0062] <About the overall structure of a lever hoist>

[0063] Figure 1This is a front view showing an example structure of the lever hoist 10 according to the first embodiment of the present invention. Figure 2 It means Figure 1 The diagram shows a cross-sectional view of the structure of the lever hoist 10.

[0064] like Figure 2 As shown, the load pulley 20, which is attached to the chain C1, is supported in a rotatable manner between a pair of frames 11 and 12 of the lever hoist 10. A load gear 21, which meshes with the small-diameter gear portion 32 of the reduction gear 30 (described later), is provided on the load pulley 20 in a non-rotatable manner. The detailed structure of the load pulley 20 will be explained later.

[0065] Furthermore, the load pulley 20 has a through hole 20a extending axially (X direction), and the drive shaft 25 is inserted into the hollow hole of the load pulley 20. It should be noted that the drive shaft 25 corresponds to a shaft-shaped member. A male threaded portion 26 is provided on the outer periphery of the drive shaft 25, which meshes with the female threaded member 35 constituting the braking device 70 described later. A small gear 27 is provided on the other end side (X2 side) of the drive shaft 25, which meshes with the large-diameter gear portion 31 of the reduction gear 30. Additionally, a small-diameter gear portion 32 that meshes with the load gear 21 is integrally provided on the reduction gear 30.

[0066] Additionally, a housing 13 is mounted on the frame 11 to protect the drive components such as the reduction gear 30 or load gear 21. Furthermore, the male threaded portion 26 engages 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 engage with a switching pawl 40 disposed on the operating lever 50. The switching pawl 40 is, for example, one pawl on each side; by swinging the operating lever 50 while the switching pawl 40 is engaged with the switching gear 37, driving force is transmitted to the female threaded member 35.

[0067] Additionally, the switching knob 45 is coaxially fixed to the switching pawl 40. By switching the knob 45, the transmission of driving force to the female threaded member 35 can be switched to either the winding direction, the rewind direction, or a neutral position. For example, in... Figure 1 If the lower side (Z2 side) of the switching knob 45 is pushed to the left, the switching pawl 40 for winding engages with the switching gear 37. Thus, when the operating lever 50 is repeatedly swung, the switching gear 37 rotates in the winding direction but not in the rewinding direction. This corresponds to the winding state of chain C1.

[0068] On the other hand, for example, if the lower side (Z2 side) of the switching knob 45 is pushed towards Figure 1On the right side, the switching pawl 40 for winding engages with the switching gear 37. Thus, when the operating lever 50 is repeatedly swung, the switching gear 37 rotates in the winding direction but not in the coiling direction. Furthermore, when switched to the neutral position, it can transition to an idle state where the chain C1 can be pulled out by hand (at this time, the load pulley 20 and drive shaft 25 also rotate). Further, the chain C1 can be coiled or wound without operating the operating lever 50, but rather by operating the idle handle 60 (described later).

[0069] Furthermore, a cam member 55 is mounted on the drive shaft 25 in a non-rotatable state, such as a spline connection or key connection. Moreover, a member called a freewheeling handle 60 is mounted on the cam member 55 in a manner that allows it to slide axially relative to the cam member 55 by a predetermined amount. Figure 2 At its position, the idler handle 60 is engaged with the cam member 55 in a manner that prevents it from rotating relative to the cam member 55. However, when the idler handle 60 is slid in the X1 direction, it can rotate within a certain range relative to the cam member 55. The idler handle 60 is a generally circular handle-shaped portion that can rotate together with the drive shaft 25 via the cam member 55, and the operator can hold the idler handle 60 by hand.

[0070] The idler lever 60 is connected to the female threaded member 35 via a first torsion spring (not shown), and further connected to one end of the drive shaft 25 via a second torsion spring (not shown). When the switching knob 45 is in the neutral position, the idler lever 60 is moved towards... Figure 2 When the lever 60 slides in the X1 direction, it rotates a predetermined amount in the winding direction using the force of the second torsion spring (free-spinning spring). The first torsion spring mounted on the lever 60, which has rotated a predetermined amount, also rotates in the winding direction. The force applied to the female thread member 35, which rotates it in the winding direction, is released, and the lever 60 switches to free-spinning mode. Here, regardless of whether it is in free-spinning mode or not, when the operator holds the lever 60 and rotates it, rotational force can be transmitted to the drive shaft 25. Therefore, by rotating the lever 60, the length of the chain C1 can be quickly adjusted, or the lever 60 can be switched to free-spinning mode by sliding. In addition, even in free-spinning mode, when a predetermined tension or higher is applied to the chain C1 in the winding direction, the female thread member 35 rotates relative to the drive shaft 25 in the tightening direction, and the brake of the braking device 70 (described later) is activated.

[0071] <Regarding the braking device 70>

[0072] like Figure 2As shown, a braking device 70 is mounted on the drive shaft 25, which is connected to the load pulley 20 via a gear. The braking device 70, as a main structural element, includes: a brake bracket 71, brake plates 72a and 72b, a ratchet 80, a pawl member 90, a pawl shaft 115, a bushing 92, and a female threaded member 35. Furthermore, the ratchet 80, the pawl member 90, and the pawl shaft 115 correspond to the main structural elements of a ratchet mechanism.

[0073] The brake bracket 71 has a flange portion 71a and a hollow bushing portion 71b. The flange portion 71a is configured such that its diameter is larger than that of the hollow bushing portion 71b, and it is able to abut against the brake plate 72a.

[0074] The hollow bushing portion 71b is located on the side closer to the female thread member 35 (X1 side) than the flange portion 71a, and it supports the ratchet 80 via the bushing 92. In addition, the inner circumference of the hollow bushing portion 71b engages with the drive shaft 25 via a key connection or spline connection, thereby allowing the drive shaft 25 and the brake bracket 71 to rotate as a unit.

[0075] Furthermore, brake plates 72a and 72b are axially supported on the hollow bushing portion 71b between the flange portion 71a and the ratchet 80, and between the female thread member 35 and the ratchet 80, respectively. The brake plates 72a and 72b are, for example, friction members formed from a specified friction material into a plate shape, or disposed on both sides of the ratchet 80 by means of sintering or other methods.

[0076] When the female threaded member 35 is rotated in the winding direction, through its interaction with the male threaded portion 26 of the drive shaft 25, the female threaded member 35 presses the ratchet 80 and brake plates 72a and 72b together toward the brake bracket 71, thereby transmitting driving force to the drive shaft 25. On the other hand, in this state, even if the drive shaft 25 is rotated in the winding direction, the female threaded member 35 will still press the ratchet 80 and brake plates 72a and 72b together toward the brake bracket 71. At this time, the ratchet 80 cannot rotate in the winding direction under the action of the pawl member 90, so the braking force generated by friction acts on the brake device 70. Thus, the rotation of the drive shaft 25 in the winding direction can be stopped. Conversely, if the female threaded member 35 is rotated in the winding direction, the pressing force generated by the female threaded member 35 is correspondingly reduced, the braking force of the brake device 70 is reduced, and thus rotation in the winding direction is possible.

[0077] Furthermore, a pawl shaft 115 is integrally provided on the limiting member support member 120 (described later), and the pawl member 90 is rotatably supported on the pawl shaft 115. Additionally, a coil portion 93a of a torsion spring 93 is mounted on the pawl shaft 115, and the torsion spring 93 applies a force in the direction that presses the pawl member 90 against the ratchet teeth 83 of the ratchet 80. Thus, the ratchet 80 is configured to rotate in the coiling direction, and in the winding direction, its rotation is limited according to each pitch angle divided by the number of teeth of the ratchet 80. Furthermore, a pair of pawl members 90 are provided, arranged 180 degrees apart in the circumferential direction of the ratchet 80.

[0078] <Regarding Brake Cover 14 and Lock Cover 15>

[0079] like Figure 2 and Figure 3 As shown, the aforementioned braking device 70 is covered by the brake cover 14, thereby preventing dust or rainwater from entering the brake device 70 located inside the brake cover 14. The brake cover 14 is mounted on a lock cover 15. That is, as... Figure 3 As shown, the flange portion 14a of the brake cover 14 abuts against the lock cover 15. In addition, an insertion hole 14a1 is provided on the flange portion 14a, and a stay bolt B1 (corresponding to the fastening member) is inserted into the insertion hole 14a1.

[0080] Additionally, the lock cover 15 is a cover that covers the rotary locking device 100, which will be described later. By covering the rotary locking device 100 with the lock cover 15, dust or rainwater is prevented from entering the rotary locking device 100. The lock cover 15 has a raised portion (side surface) 15a and an opposing surface 15b perpendicular to the raised portion 15a. The opposing surface 15b is opposite to the frame 12 at a predetermined interval and abuts against the flange portion 14a.

[0081] In addition, the thickness of the limiting member locking member 110 (described later) constituting the rotary locking device 100 is set to be the same as the height (internal dimension) of the upright portion 15a from the opposite surface 15b.

[0082] Furthermore, a through hole 12a is provided on the frame 12 for inserting the support bolt B1. The support bolt B1, inserted through this through hole 12a, is configured such that its load pulley 20 side (X2 side) has a larger diameter. Through this change in the diameter of the support bolt B1, a first stepped portion B1a is provided on the support bolt B1. By abutting this first stepped portion B1a against the load pulley 20 side (X2 side) of the frame 12, movement of the frame 12 towards the load pulley 20 side (X2 side) is restricted. In this restricted state, the support bolt B1 is welded to the frame 12.

[0083] Furthermore, a through hole 15b1 is provided on the opposite surface 15b of the lock cover 15, and the support bolt B1 is inserted into this through hole 15b1. Further, an insertion hole 14a1 is provided on the flange portion 14a of the brake cover 14, and the support bolt B1 is inserted into this insertion hole 14a1. Here, a second step portion B1b, identical to the first step portion B1a described above, is provided on the support bolt B1, and the freewheeling handle 60 side (X1 side) is provided with a smaller diameter through this second step portion B1b. Additionally, a male thread portion B1c is provided at the portion of the support bolt B1 that protrudes from the insertion hole 14a1 towards the freewheeling handle 60 side (X1 side). Therefore, by screwing the nut (cap nut) N1 into the male thread portion B1c via the washer W, the brake cover 14 and the lock cover 15 are securely fastened.

[0084] Here, the aforementioned second step portion B1b is positioned at the midpoint of the through hole 14a1. Consequently, a gap S1 is provided between the second step portion B1b and the surface of the flange portion 14a. Therefore, even when the nut N1 is screwed into the male thread portion B1c, the second step portion B1b will not protrude towards the surface of the flange portion 14a.

[0085] Furthermore, as described above, by setting the thickness of the limiting member locking member 110 (described later) to the same level as the height (internal dimension) of the upright portion 15a from the opposing surface 15b, the limiting member locking member 110 is securely fixed between the frame 12 and the opposing surface 15b, and the front end of the upright portion 15a is in firm contact with the frame 12. However, it is also possible to configure the height (internal dimension) of the upright portion 15a to be slightly larger than the thickness of the limiting member locking member 110 (described later). In this case, by tightening the nut N1, the opposing surface 15b is slightly flexed, thereby securing the front end of the upright portion 15a in firm contact with the frame 12, and the limiting member locking member 110 is securely fixed (clamped).

[0086] <Regarding the load pulley 20 and the rotary locking (cargo falling prevention) device 100>

[0087] Next, the load pulley 20 and the rotation lock (cargo falling prevention) device 100 will be described. Figure 4 This is a cross-sectional view showing the structure near the rotary locking (cargo falling prevention) device 100. Figure 5 It means Figure 4 An exploded perspective view of the structure of the rotary locking (cargo falling prevention) device 100 shown. Figure 4 and Figure 5As shown, the rotary locking (cargo falling prevention) device 100 includes, as its main structural components, a limiting member locking member 110, a limiting member support member 120, a retaining plate 130, a limiting member 140, and a force application unit 150. Furthermore, the limiting member locking member 110 corresponds to a limiting member locking mechanism, and the force application unit 150 corresponds to a force application mechanism.

[0088] like Figures 3 to 5 As shown, in this embodiment, a pair of limiting member locking members 110 are installed on the ratchet 80 side of the frame 12. In this embodiment, the limiting member locking member 110 is a long, plate-shaped member that is relatively long in the Y direction, and a space SP1 is formed between the two limiting member locking members 110. Therefore, compared with the case where the limiting member locking members are distributed around the entire circumference of the outer periphery of the limiting member support member 120 and the retaining plate 130, the limiting member locking members 110 can be made lighter.

[0089] Each limiting member locking component 110 is mounted on the frame 12 using two support bolts B1. To enable this mounting, two mounting holes 111 are provided on the limiting member locking component 110, and the support bolts B1 are inserted into the mounting holes 111. In this embodiment, a pair (two) of mounting holes 111 are provided, but it is also possible to provide three or more.

[0090] Additionally, an inner protrusion 112 is provided on the limiting member locking member 110. The inner protrusion 112 is a portion of the limiting member locking member 110 that protrudes towards the center of the shaft hole 12b of the frame 12. Furthermore, the shaft hole 12b is a hole through which the aforementioned drive shaft 25 and load pulley 20 are inserted.

[0091] The inner protrusion 112 is positioned relative to the outer peripheral surfaces of the limiting member support member 120 and the retaining plate 130 (described later) with a slight gap. This configuration ensures that the rotation of the limiting member support member 120 and the retaining plate 130, which support the limiting member 140 in the retaining position, is not impeded. Furthermore, in this embodiment, one inner protrusion 112 is provided on each limiting member locking member 110. Therefore, two inner protrusions 112 are arranged at 180-degree intervals in the circumferential direction.

[0092] Additionally, a locking wall 114 is provided on the inner protrusion 112. The locking wall 114 is on the other side of the inner protrusion 112 in the direction of rotation (in... Figure 4 and Figure 5The wall surface of the inner protrusion 112 (clockwise side) is such that when the limiting member 140, which rotates in a rotational direction (rewinding direction), protrudes radially outward from the limiting member support member 120, it collides with the locking wall 114, thereby stopping the rotation of the load pulley 20. Therefore, the radial direction of the locking wall 114 relative to the shaft hole 12b is set at an angle that prevents the limiting member 140 (described later) from being pushed back towards the rotation axis. Furthermore, the side surface of the limiting member 140 also has an angle that prevents it from being pushed back towards the rotation axis due to collision with the locking wall 114. Additionally, as... Figure 5 As shown, a recessed portion 113 is provided, which is connected to the locking wall 114 and recessed in a direction away from the rotation axis (outer diameter side). A hook portion (not shown) of the torsion spring 93 engages with this recessed portion 113, thereby preventing the movement limiting member 140 from contacting the hook portion of the torsion spring 93.

[0093] In addition, such as Figure 5 As shown, a pawl shaft 115 is provided on the limiting member locking member 110. In this embodiment, the pawl shaft 115 is integrated with the other parts of the limiting member locking member 110. To achieve such integration, it is preferable to form the limiting member locking member 110 by casting (e.g., lost-wax casting). However, it is also possible to configure it such that only the pawl shaft 115 is formed separately, and the pawl shaft 115 is pressed into a mounting hole or the like present in the limiting member locking member 110 for mounting.

[0094] Here, as Figure 4 As shown in the cross-sectional view, multiple ribs 116 are arranged inside the limiting member locking member 110. That is, the limiting member locking member 110 is not a solid member, but a member with a hollow portion composed of multiple ribs 116, thus enabling the limiting member locking member 110 to be lightweight. In addition, by arranging two ribs 116 in an X-shape on the root side of the pawl shaft 115, it is possible to withstand the load in the axial direction (axial direction) of the pawl shaft 115.

[0095] In addition, in this embodiment, such as Figure 4 As shown, the sidewall of the inner protrusion 112 opposite to the locking wall 114 can also function as the locking wall 114. Alternatively, it can be configured such that the sidewall facing the concave portion 113... Figure 4 and Figure 5 The sidewall on the clockwise side is inclined at a predetermined angle or more relative to the radial direction, so that the limiting member 140 protruding from the limiting member storage part 123 is stored in the limiting member storage part 123 as described later.

[0096] Next, the limiting member support member 120 will be described. The limiting member support member 120 has a central hole 121, and by mounting it to the drive shaft 25 at this central hole 121, the limiting member support member 120 and the drive shaft 25 rotate integrally. Furthermore, regarding the mounting of the limiting member support member 120 relative to the drive shaft 25, any method such as a locking screw, key connection, or spline connection can be used, as long as the necessary torque can be transmitted.

[0097] In addition, such as Figure 5 As shown, a bearing sleeve portion 122 is provided on the limiting member support member 120. The bearing sleeve portion 122 is a hollow shaft-shaped portion that protrudes axially (X direction) and is rotatably embedded in the central hole 132 provided in the retaining plate 130.

[0098] Furthermore, the limiting member support member 120 is provided with a limiting member receiving portion 123 formed from its central hole 121 side toward its outer peripheral side. The limiting member receiving portion 123 is the part that receives the limiting member 140 described later, and its outer peripheral side is open. Therefore, the limiting member 140 received in the limiting member receiving portion 123 can protrude toward its outer peripheral side and is supported by the side wall 123a of the limiting member receiving portion 123 so that it can slide.

[0099] Furthermore, the limiting member storage portion 123 is formed by clamping a narrow plate portion 120a and a wide plate portion 120b. In the event of a collision between the limiting member 140 (described later) and the locking wall 114, the narrow plate portion 120a is located opposite the inner protrusion 112, while the wide plate portion 120b is located away from the inner protrusion 112 (locking wall 114) across the limiting member storage portion 123. Figure 4 In the structure shown, the narrow plate portion 120a is located on the left side of the movement limiting member storage portion 123, and the wide plate portion 120b is located on the right side of the movement limiting member storage portion 123. Here, the wide plate portion 120b is configured such that its circumferential width is wider than that of the narrow plate portion 120a. Therefore, it is ensured that even if the movement limiting member 140 collides with the locking wall 114, the wide plate portion 120b can withstand the strength of the impact.

[0100] In addition, an insertion hole 124 is provided on the limiting member support member 120. The insertion hole 124 is a recessed hole in the outer peripheral surface of the limiting member support member 120, located at a point that does not interfere with the central hole 121 and the limiting member receiving portion 123. Figure 4 The recess is formed from the outer peripheral surface opposite to the limiting member receiving portion 123. By inserting one end of the locking pin 152 (described later) into the insertion hole 124, the limiting member support member 120 supports the locking pin 152.

[0101] Next, the retaining plate 130 will be described. The retaining plate 130 constitutes a retaining mechanism. The retaining plate 130 is circular and has a central hole 132 at its radial center. By inserting the bearing sleeve portion 122 into this central hole 132, the retaining plate 130 is supported relative to the limiting member support member 120 so that it can rotate coaxially. Furthermore, the distance (i.e., radius) from the center of rotation to the outermost circumference of the retaining plate 130 is approximately the same as the distance to the outermost circumference of the limiting member support member 120. However, the radius of either the limiting member support member 120 or the retaining plate 130 can also be set to be larger.

[0102] In this embodiment, a pair of retaining plates 130 are provided, and a limiting member support member 120 is sandwiched between the pair of retaining plates 130. Furthermore, the retaining plates 130 are connected to each other at predetermined intervals using a connecting member R1.

[0103] Additionally, a guide groove 136 is provided on the retaining plate 130. Figure 6 This is a top view showing the structure of the retaining plate 130. The guide groove 136 is the portion into which the limiting protrusion 141 (described later) of the limiting member 140 enters and guides the movement of the limiting protrusion 141. Its appearance is formed as follows: a groove extending in an arc shape is added to the radial center side of a generally triangular portion. Specifically, as... Figure 6 The roughly triangular retaining protrusion 137 shown enters the guide groove 136. Through this entry, the guide groove 136 is provided with three grooves: a allowable groove 136a, a clearance groove 136b, and a return limiting groove 136c.

[0104] The permissible groove 136a is a groove that allows the limiting protrusion 141 to move radially. Therefore, in Figure 6 In this configuration, the inner wall 136a1 located below the allowable groove 136a is configured to be parallel to the radial direction (the direction of a radial line extending from the center of the central hole 132). Furthermore, the width of the allowable groove 136a is defined by the distance between the front end portion 137a of the retaining protrusion 137 that protrudes most towards the inner wall 136a1 and the aforementioned inner wall 136a1.

[0105] Furthermore, the clearance groove 136b extends circumferentially away from the allowable groove 136a from the front end 137a of the protrusion. Figure 6The groove is recessed in a manner resembling the right side of the center. The limiting protrusion 141 can be located in the clearance groove 136b with a free play. Here, the inner wall of the outer diameter side of the clearance groove 136b (designated as the first limiting wall 136b1) engages with the limiting protrusion 141 to hold the limiting member 140 in a predetermined position on the limiting member support member 120. In addition, with the limiting protrusion 141 housed in the clearance groove 136b, the outer diameter side of the limiting member 140 is housed in the limiting member housing 123 in a state where it does not protrude further outward than the outer peripheral surface of the limiting member support member 120.

[0106] Here, the circumferential length of the clearance groove 136b is formed to be longer than the length determined by the angle γ described below. That is, if the operation is interrupted during the winding operation, the ratchet 80 can rotate freely in the winding direction by the angle (tooth pitch angle) obtained by dividing one revolution by the number of teeth. This angle is set as angle γ (not shown). In this case, it is preferable that the rotary locking device 100 also delays the operation by an angle larger than angle γ. Therefore, in the retracted state of the limiting member 140, the circumferential length of the clearance groove 136b into which the limiting protrusion 141 enters is extended by at least angle γ or more. Moreover, it is preferable that the limiting member 140 is held until the retaining plate 130 rotates relative to the limiting member support member 120 at an angle of angle γ or more relative to the drive shaft 25 and the limiting member support member 120 in a second rotational direction opposite to the winding direction.

[0107] Furthermore, in this embodiment, the clearance groove 136b is sufficiently long relative to the angle γ. If the clearance groove 136b were short, the rotary locking device 100 would easily operate during the idle operation of quickly pulling the chain C1 in the winding direction after switching the switch knob 45 to the neutral position and operating the idle lever 60 to set it to idle mode, thus reducing the convenience of pulling out the chain C1. Therefore, in order to prevent the rotary locking device 100 from immediately operating during the idle operation of manually pulling out the chain C1 after switching the switch knob 45 to the neutral position and setting it to idle mode, the length of the clearance groove 136b is sufficiently long relative to the angle γ. This prevents the rotary locking device 100 from operating and entering a rotary-locked state during the aforementioned idle operation.

[0108] Furthermore, the return limiting groove 136c is positioned circumferentially away from the allowable groove 136a. Figure 6A recessed groove (upper middle side). The limiting protrusion 141 can be positioned in the return limiting groove 136c with clearance. However, a second limiting wall 136c1 is provided on the return limiting groove 136c. The second limiting wall 136c1 engages with the limiting protrusion 141, thereby maintaining the outer diameter side of the limiting member 140 protruding from the outer peripheral surface of the limiting member support member 120. That is, the second limiting wall 136c1 is used to limit the limiting member 140 from being completely housed in the wall surface of the limiting member housing 123.

[0109] Furthermore, the second limiting wall 136c1 is inclined towards the inner diameter side as it approaches the allowable groove 136a. Therefore, when the limiting protrusion 141 has entered the return limiting groove 136c, by rotating the limiting member support member 120 and the limiting member 140 relative to the retaining plate 130, the engagement between the limiting protrusion 141 and the second limiting wall 136c1 is released as the limiting protrusion 141 moves towards the allowable groove 136a. As a result, the limiting member 140 can move towards the inner diameter side of the limiting member receiving portion 123. On the other hand, after the limiting member 140 slides from the predetermined position in the centrifugal direction and the limiting protrusion 141 passes the front end 137a of the protrusion, even if the rotational acceleration of the drive shaft 25 in the first rotational direction decreases, the limiting protrusion 141 engages with the second limiting wall 136c1, thereby reliably engaging the limiting member 140 with the locking wall 114, and maintaining this engagement during the period when the load in the first rotational direction continues to act on the drive shaft 25.

[0110] Furthermore, a limiting member 140 is housed in the limiting member storage portion 123 of the aforementioned limiting member support member 120. This limiting member 140 is housed in the limiting member storage portion 123 in a state in which it can slide from the storage position in the centrifugal direction.

[0111] Here, the inner wall surface (inner bottom surface) of the inner side (rotation axis side) of the limiting member storage portion 123 is set to be approximately semi-circular. In the following description, this semi-circular inner wall surface (inner bottom surface) is referred to as the arc-shaped bottom surface 123b. By setting such an arc-shaped bottom surface 123b, stress concentration areas will not form on the inner side of the limiting member storage portion 123. That is, when the limiting member 140 (described later) collides with the locking wall 114, its impact is also transmitted to the inner wall surface of the limiting member storage portion 123. If there is a stress concentration area during the transmission of this impact, it will become a cause of damage to the limiting member support member 120. However, by forming the inner wall surface of the inner side of the limiting member storage portion 123 into a semi-circular arc-shaped bottom surface 123b, stress concentration areas will not form on the semi-circular arc-shaped bottom surface 123b when the limiting member 140 collides with the locking wall 114. In addition, the arc surface 143 described later abuts against the arc bottom surface 123b.

[0112] In addition, such as Figure 7 As shown, with the limiting member 140 housed in a predetermined position within the limiting member housing 123, the outer peripheral surface (the surface away from the radial center) of the limiting member 140 is located closer to the inner diameter than the outer peripheral surface of the limiting member support member 120 relative to the rotation axis center. Furthermore, it is preferable that the distance from the outer peripheral surface of the limiting member support member 120 is the same as the distance from the rotation axis center of the retaining plate 130 to its outer peripheral surface. Additionally, the dimension of the outer peripheral surface of the limiting member 140 away from the rotation center needs to be set so as not to obstruct the rotation of the drive shaft 25.

[0113] Here, a cylindrical limiting protrusion 141 is provided on the limiting member 140. The limiting protrusion 141 protrudes from the surface (both front and back) of the limiting member 140 opposite to the retaining plate 130 toward the retaining plate 130 in the X-axis direction. Additionally, as... Figure 4 , Figures 7-9 As shown, the limiting protrusion 141 is positioned closer to the axial center of the drive shaft 25 (limiting member 140) than the center of the limiting member 140 in the depth direction (radial direction of the limiting member support member 120). Alternatively, the limiting protrusion 141 can be integrally formed with the limiting member 140, but it can also be configured such that a mounting hole is provided on the limiting member 140, allowing a shaft-like member or pin to engage with the mounting hole to form the limiting protrusion 141.

[0114] The limiting protrusion 141 enters the guide groove 136. Thus, when the relative rotational positions of the limiting member support member 120 and the retaining plate 130 change, the limiting protrusion 141 slides within the guide groove 136. Furthermore, when the limiting protrusion 141 is located in the allowable groove 136a, the limiting member 140 can protrude outwards according to the centrifugal force acting on the limiting member 140 or the pressing force from the second limiting wall 136c1 caused by the force of the force-applying spring 151.

[0115] Here, the outermost radially outermost peripheral surface 142 of the limiting member 140 is also provided in an arc shape, similar to the outer peripheral surface of the limiting member support member 120 and the outer peripheral surface of the retaining plate 130. However, the outer peripheral surface 142 can be provided in a straight line or in other shapes.

[0116] On the other hand, the outer peripheral surface of the movement limiting member 140 at a position near the radial center is set to be approximately semi-circular. Hereinafter, this semi-circular outer peripheral surface will be referred to as the arc surface 143. This arc surface 143 is the portion that abuts against the arc bottom surface 123b of the aforementioned movement limiting member receiving portion 123.

[0117] Here, by installing the limiting member 140, two retaining plates 130, and the force-applying unit 150 on the limiting member support member 120, the connecting member R1 (see reference) is utilized. Figure 5 Two retaining plates 130 are connected at a predetermined interval, and the limiting member 140 is held in a predetermined position in the limiting member storage portion 123 of the limiting member support member 120 by utilizing the inner wall of the guide groove 136, thereby achieving modularity. This modularity allows for easy and reliable assembly to the drive shaft 25, as well as disassembly and replacement during maintenance. In particular, the operation of the modular structure can be checked or adjusted before assembly to the lever hoist 10 (winch). Furthermore, even under heavy loads on the limiting member 140, the pair of retaining plates 130 reliably hold the limiting member 140 in the limiting member storage portion 123 of the limiting member support member 120.

[0118] In this embodiment, the connecting member R1 consists of a rivet and a washer (spacer). Specifically, a washer is placed between a pair of retaining plates 130, allowing the rivet to pass through the hole 131 formed in the retaining plate 130 and the washer. Then, by plastically deforming the other end of the rivet, the pair of retaining plates 130 are connected while maintaining a predetermined interval.

[0119] Next, the force-applying unit 150 will be described. For example... Figure 4 As shown, the force-applying unit 150 includes a force-applying spring 151, a locking pin 152 at one end, and a connecting member R1 corresponding to the locking pin at the other end. In this embodiment, the force-applying spring 151 is a tension spring. As a structure of the force-applying unit 150, in addition to a tension spring, it may also include a compression spring or a torsion spring, as long as it applies force to the retaining plate 130, causing it to move relative to the limiting member support member 120. Figure 4 The structure can be rotated in one direction of counterclockwise rotation (the direction of rewind; the first direction of rotation).

[0120] Furthermore, as described above, one end of the locking pin 152 is installed by inserting it into the insertion hole 124 of the limiting member support member 120. Additionally, one end of the force-applying spring 151 is engaged with this locking pin 152. Furthermore, the other end of the locking pin also serves as the connecting member R1. That is, the other end of the force-applying spring 151 is engaged with the connecting member R1 in the insertion hole portion 131.

[0121] Here, the point of action of the force-applying spring 151, which is engaged in one end of the locking pin 152, and the point of action of the force-applying spring 151, which is engaged in the connecting member R1 corresponding to the other end of the locking pin, differ from the rotation center by a predetermined angle θ. Therefore, the force-applying spring 151 applies force in such a way that this angle θ decreases.

[0122] In addition, Figure 5In the structure shown, including the connecting member R1 corresponding to the locking pin at the other end, a total of three connecting members R1 are provided, and corresponding to these three connecting members R1, a total of three holes 131 are provided on the retaining plate 130. However, as Figure 10 As shown, it can also be configured such that a total of four connecting members R1 are provided, and a total of four holes 131 are provided on the retaining plate 130 corresponding to the four connecting members R1. Furthermore, the number of connecting members R1 and the number of holes 131 can be arbitrary. Additionally, as long as the connection is made while maintaining the interval between a pair of retaining plates 130, the connecting members R1 can be any component such as screws and nuts.

[0123] in addition, Figure 10 Involving Figure 1 The diagram shown is a variation of the lever hoist, illustrating the structure near the rotary locking (cargo drop prevention) device 100, and providing a perspective view of the positional relationships of the various parts of the rotary locking (cargo drop prevention) device 100 before its operation. Figure 10 In the structure shown, two of the four connecting members R1 are arranged adjacent to the force spring 151. This prevents the force spring 151 from disengaging from the hole 131. Furthermore, it prevents the force spring 151 from flying out due to the centrifugal force generated by the rotation of the retaining plate 130 when one end of the force spring 151 disengages from one end retaining pin 152, or the other end disengages from the connecting member R1 (corresponding to the other end retaining pin).

[0124] In addition, Figure 10 In the structure shown, with Figure 4 and Figure 5 Unlike the structures shown, the limiting member storage section 123 does not have an arc-shaped bottom surface 123b, but instead has a straight bottom surface (symbol omitted). Similarly, the limiting member 140 does not have an arc-shaped surface 143, but instead has a straight bottom surface (symbol omitted).

[0125] <Regarding its function>

[0126] In the rotary locking (cargo falling prevention) device 100 with the above structure, consider the following situation: that is, during the winding operation of the lever hoist 10, if the brake device 70 is damaged, the drive shaft 25 will start to rotate rapidly in the winding direction due to the tension applied to the chain C1 by the suspension load, etc.

[0127] Figure 7 It means Figure 1 The diagram shows the structure near the rotary locking (cargo drop prevention) device 100 in the lever hoist 10, and is a perspective view showing the positional relationship of each part of the rotary locking (cargo drop prevention) device 100 before operation. Additionally, Figure 8 It is a perspective representation from Figure 7 The diagram shows the positional relationship of various parts in a state where the limiting member support member 120 and the retaining plate 130 rotate relative to each other and the limiting protrusion 141 reaches the allowable groove 136a. Additionally, Figure 9 It is a perspective representation from Figure 8 The diagram shows the positional relationship of various parts in the state where the limiting member 140 protrudes to the outer diameter side and the limiting protrusion 141 is located in the state of returning the limiting groove 136c.

[0128] Initially, the drive shaft 25, which had lost its braking force, and the limiting member support 120, due to the tension applied to the chain C1, together with the limiting member 140, acted as... Figure 7 A sharp increase in rotational speed occurs in one of the counterclockwise rotational directions (the winding direction). At this time, the force applied by the force spring 151 serves the following purpose: with the limiting protrusion 141 of the limiting member 140 located at the far end of the clearance groove 136b (the end away from the allowable groove 136a), the retaining plate 130 follows the rotation of the limiting member 140. However, when the inertial force on the retaining plate 130 exceeds the force of the force spring 151, the limiting protrusion 141 moves away from the far end of the clearance groove 136b (the end away from the allowable groove 136a). Furthermore, when the drive shaft 25 accelerates and rotates together with the limiting member support member 120 and the limiting member 140 in the direction that the limiting protrusion 141 leaves the end (cannot be followed), the force spring 151 extends due to the inertial force acting on the retaining plate 130, and the limiting protrusion 141 of the limiting member 140 slides toward the allowable groove 136a in the clearance groove 136b.

[0129] Furthermore, even if the centrifugal force generated by the rotation of the limiting member support member 120 and the limiting member 140 causes the limiting member 140 to protrude to the outer diameter side, the limiting protrusion 141 is restricted by the first limiting wall 136b1 before it reaches the allowable groove 136a, thereby limiting the protrusion of the limiting member 140 to the outer diameter side.

[0130] Furthermore, when the limiting protrusion 141 moves relative to the clearance groove 136b Figure 8In the indicated position, the limiting member 140 can protrude outwards. That is, the limiting member 140, having released the engagement (holding) state between the limiting protrusion 141 and the first limiting wall 136b1, protrudes outwards from the limiting member receiving portion 123 under the action of centrifugal force. However, the amount of protrusion outwards is within the range up to the outermost circumference of the guide groove 136. On the other hand, after the limiting member 140 slides in the centrifugal direction from the predetermined position and the limiting protrusion 141 passes the front end portion 137a of the protrusion, even if the rotational acceleration of the drive shaft 25 in the first rotational direction decreases, the limiting protrusion 141 will be pressed by the second limiting wall 136c1 due to the force of the force spring 151. Through this pressing, the limiting member 140 protrudes to a position reliably engaged with the locking wall 114, and this engagement is maintained during the period when the load in the first rotational direction continues to act on the drive shaft 25.

[0131] Furthermore, if the limiting member 140 protruding from the limiting member storage section 123 continues to rotate in a rotational direction (rewinding direction) that is counterclockwise, then as Figure 9 As shown, the limiting member 140 collides with the locking wall 114 of the limiting member locking member 110. As a result, the rotation of the limiting member support member 120 and the drive shaft 25 in one rotational direction (rewinding direction) is stopped, thereby stopping the falling of the goods.

[0132] Furthermore, after the limiting member 140 collides with the locking wall 114, the limiting protrusion 141 enters the return limiting groove 136c. Thus, after the drive shaft 25 stops, the limiting protrusion 141 receives a counter-clockwise force from the second limiting wall 136c1 through the force of the force spring 151, maintaining the state of the limiting protrusion 141 entering the return limiting groove 136c. At this time, even if the limiting member 140 accidentally attempts to return to the limiting member storage section 123, the engagement of the limiting protrusion 141 with the second limiting wall 136c1 restricts the returning of the limiting member 140 to the limiting member storage section 123. Therefore, the rotation of the drive shaft 25 is stopped, preventing the goods from falling again.

[0133] Next, with the braking device 70 operating normally, consider the idle mode, which is a state where the chain C1 can be manually pulled out in the winding direction. The lever hoist 10 has the function of enabling this idle mode under no-load conditions. Specifically, it has the function of releasing the brake via the threaded member 35 of the braking device 70 through the action of an idle spring (not shown). In the idle mode, the length of the chain C1 can be adjusted at a faster speed than when operating via the lever 50. When switching to the idle mode, there are two methods: an automatic idle mode where switching can be performed simply by setting the switching knob 45 to the neutral position under no-load conditions, and a method where, after setting the switching knob 45 to the neutral position, a further prescribed operation of the idle handle 60 is performed to switch to the idle mode. In this embodiment, the latter structure, where the switching knob 45 is set to the neutral position and a further prescribed operation of the idle handle 60 is performed to switch to the idle mode, is described in detail here.

[0134] In this idling mode, the braking force of the braking device 70 is temporarily inactive. However, for safety reasons, it becomes a mechanism where the braking device 70 activates when a specified tension or higher is applied to the chain C1 in the winding direction, thereby stopping the rotation of the drive shaft 25. On the other hand, since the braking device 70 with ratchet 80 used in the lever hoist 10 does not activate in the winding direction, the length of the chain C1 can be adjusted at a faster speed than in the winding direction. In this state of the lever hoist 10, the rotation locking (cargo drop prevention) device 100 also operates as infrequently as possible in the winding direction (another rotation direction), resulting in good operability.

[0135] When the operator pulls chain C1 in the winding direction, the load pulley 20 rotates in the winding direction, and the drive shaft 25, the limiting member support member 120, and the limiting member 140 also rotate in the winding direction. At this time, the inertial force acting on the holding plate 130 acts in the direction that presses the limiting protrusion 141 against the very end of the clearance groove 136b (the end away from the allowable groove 136a). Therefore, even if the limiting member 140 tries to protrude from the inside of the limiting member receiving part 123 to the outer diameter side, it cannot protrude because the limiting protrusion 141 is restricted by the first limiting wall 136b1.

[0136] On the other hand, when the operator pulls chain C1 in the rewind direction, the load pulley 20 rotates in the rewind direction, and the drive shaft 25, the limiting member support member 120, and the limiting member 140 also rotate in the rewind direction. At this time, the following situation occurs: due to the accelerated rotation of the limiting member support member 120 and the limiting member 140, the retaining plate 130 rotates relative to the force of the force-applying spring 151 in a way that leaves it in place, and the limiting protrusion 141 leaves the very end of the clearance groove 136b (the end away from the allowable groove 136a). In this case, if the length of the clearance groove 136b is short, the limiting protrusion 141 can more easily reach the allowable groove 136a, after which the limiting member 140 protrudes outward and becomes locked, causing the locking wall 114 to collide with the limiting member 140. In this case, the operator's work of pulling chain C1 in the rewind direction is interrupted, and the locked state needs to be released, thus reducing workability.

[0137] However, in this embodiment, the length of the clearance groove 136b is set to be sufficiently long compared to the aforementioned angle γ, such that during rotational acceleration to the extent that the operator pulls the chain C1 in the winding direction, even if the limiting protrusion 141 moves slightly within the clearance groove 136b, it cannot reach the extent that the allowable groove 136a is present. Therefore, the operator's work of pulling the chain C1 in the winding direction will not be interrupted. The length of the clearance groove 136b is set such that, in the idle mode, when the drive shaft 25 rotates rapidly in the winding direction, the braking device 70, which is temporarily released in the idle mode, brakes the rotation of the drive shaft 25 before the rotation locking device 100.

[0138] <Regarding the effects>

[0139] The rotation locking (cargo falling prevention) device 100 with the above structure includes: a limiting member support member 120, which is mounted on the drive shaft 25 (shaft-shaped member) and rotates integrally with the drive shaft 25 (shaft-shaped member); a limiting member 140, which is supported on the limiting member support member 120 in a state that can slide outward from the axial side of the drive shaft 25 (shaft-shaped member); a retaining plate 130 (retaining mechanism), which holds the limiting member 140 in a predetermined position on the limiting member support member 120; a force-applying spring 151 (force-applying mechanism), which applies a force to the retaining plate 130 (retaining mechanism) to oriented it relative to the limiting member 140 in a first rotation direction as a rotation direction; and a limiting member locking member 110 (limiting member locking mechanism), which is fixed to the frames 11, 12 that support the drive shaft 25 (shaft-shaped member) in a rotatable manner, and stops the rotation of the drive shaft 25 (shaft-shaped member) by engaging with the limiting member 140. Furthermore, when the drive shaft 25 (shaft-shaped member) accelerates in the first rotation direction, the retaining force of the retaining plate 130 (retaining mechanism) on the limiting member 140 is reduced and / or released by the inertial load of the retaining plate 130 (retaining mechanism), and the limiting member 140 protrudes from a predetermined position to a position engaged with the limiting member locking member 110 (limiting member locking mechanism), thereby stopping the rotation of the drive shaft 25 (shaft-shaped member).

[0140] With this configuration, when the drive shaft 25 (shaft-shaped member) rotates in one direction beyond a predetermined acceleration, the rotation lock (cargo drop prevention) device 100 operates, thereby stopping the rotation. Furthermore, the structure of the retaining plate 130 (retaining mechanism) can be selected such that, when the drive shaft 25 (shaft-shaped member) has rotated in a second rotational direction (another rotational direction), and the predetermined rotational speed is exceeded, the rotation lock (cargo drop prevention) device 100 operates.

[0141] Furthermore, it can be configured such that when the drive shaft 25 (shaft-shaped member) accelerates in a first rotational direction, the rotational locking (cargo falling prevention) device 100 operates at a lower speed than when rotating in the other rotational direction, through the combined effect of this acceleration and rotational speed. Additionally, in drive devices such as winches or lifting devices where the load acts only in one direction, even if the braking device 70 malfunctions, the rotation of the rotating member used for the hoisting or lifting drive can be stopped immediately, thereby preventing accidents caused by cargo falling.

[0142] In addition, in this embodiment, the retaining mechanism has a circular retaining plate 130, which has a bearing hole (center hole 132) supported by a shaft so as to be able to rotate about the axis of the shaft member. The limiting member support member 120 and the retaining plate 130 are connected by a force-applying mechanism (force-applying unit 150). The limiting member 140 has a limiting protrusion 141 protruding toward the retaining plate 130. The retaining plate 130 has a retaining protrusion 137 that engages with the limiting protrusion 141 and holds the limiting member 140 at a predetermined position in the radial direction of the limiting member support member 120. The retaining protrusion 137 has a first limiting wall 136b1 that engages with the limiting member 140 at a predetermined position in the radial direction, and a second limiting wall 136c1 that engages with the limiting member 140 at a position protruding from the predetermined position in the radial direction toward the outer diameter side.

[0143] With this configuration, the retaining mechanism (retaining plate 130) can hold the limiting member 140 in a predetermined position on the limiting member receiving portion 123 until the retaining mechanism (retaining plate 130) produces a predetermined delay relative to the limiting member support member 120, which rotates integrally with the driving shaft 25 that begins to rotate rapidly in the first rotational direction, or until the driving shaft 25 and the retaining mechanism (retaining plate 130) exceed a predetermined relative angle. Furthermore, the length of the first limiting wall 136bl of the retaining protrusion 137 can be freely set regardless of the size of the limiting member 140.

[0144] In addition, in a variation of this embodiment, when the drive shaft 25, which is a shaft-shaped member, accelerates in the first rotation direction, the retaining plate 130 constituting the retaining mechanism resists the force of the force-applying mechanism (force-applying unit 150) and rotates relative to the drive shaft 25 in a direction opposite to the first rotation direction. Until the angle of the relative rotation exceeds a predetermined angle, the retaining plate 130 constituting the retaining mechanism holds the limiting member 140 at a predetermined position in the radial direction.

[0145] With this configuration, when a lifting device such as a lever hoist 10 is equipped with the rotary locking device 100 of the present invention as an emergency stop brake, for example, it can be configured to operate with a delay compared to the normal brake (brake device 70) of the lifting device such as the lever hoist 10. Therefore, according to the rotary locking device 100 of the present invention, the operation of the normal brake (brake device 70) is not hindered in the normal use state of the lifting device such as the lever hoist 10.

[0146] In addition, in this embodiment, the shaft-shaped member (drive shaft 25) is integrally connected to the load pulley 20 on which the chain C1 is wound.

[0147] With this configuration, it is possible to reliably prevent goods from falling out of the hoist that uses the load pulley 20 to wind up or rewind the chain C1.

[0148] In addition, in this embodiment, the lever hoist 10 includes: a load pulley 20 supported by a pair of frames 11 and 12 and around which a chain C1 for lifting goods is hung; a drive shaft 25 connected to the load pulley 20 via a reduction gear 30; a braking device 70 mounted on the drive shaft 25; and an operating lever 50, which drives the load pulley 20 to rotate in the winding and rewinding direction by operation. In this lever hoist 10, a rotation locking (goods falling prevention) device 100 is arranged on the outer periphery of the drive shaft 25, and a limiting member locking member 110 (limiting member locking mechanism) is mounted on the frame 12.

[0149] With this configuration, even if the braking device 70 malfunctions, the falling of goods can be reliably prevented.

[0150] Furthermore, the lever hoist 10 (winner) of this embodiment includes: a braking device 70 having a ratchet mechanism (corresponding to ratchet 80, pawl member 90, and pawl shaft 115) and a rotation locking device 100 for locking the rapid rotation of the drive shaft 25 (shaft member). The ratchet mechanism includes: a ratchet 80 mounted around the drive shaft 25 (shaft member) and having ratchet teeth 83 on its outer periphery; a pawl member 90 engaging with the ratchet teeth 83; and a pawl shaft 115 that provides shaft support for the rotation of the pawl member 90. Furthermore, by engaging the ratchet teeth 83 with the pawl member 90, the ratchet 80 is allowed to rotate in the winding direction but is not allowed to rotate in the rewinding direction. Additionally, the rotation locking device 100 includes: a limiting member support member 120, which is mounted on the drive shaft 25 (shaft-shaped member) and rotates integrally with the drive shaft 25 (shaft-shaped member); a limiting member 140, which is supported on the limiting member support member 120 in a state that allows it to slide outward from the axial side of the drive shaft 25 (shaft-shaped member); a retaining plate 130 (retaining mechanism), which holds the limiting member 140 in a predetermined position on the limiting member support member 120; a force applying unit 150 (force applying mechanism), which applies a force to the retaining plate 130 (retaining mechanism) to cause it to rotate in the direction of retraction relative to the limiting member 140; and a limiting member locking member 110 (limiting member locking mechanism), which has a locking wall 114 that stops the rotation of the drive shaft 25 (shaft-shaped member) by abutting against the limiting member 140.

[0151] Furthermore, when the drive shaft 25 (shaft-shaped member) accelerates its rotation in the direction of rewind, the retaining force of the retaining plate 130 (retaining mechanism) on the limiting member 140 is released by utilizing the inertial load of the retaining plate 130 (retaining mechanism), causing the limiting member 140 to protrude from a predetermined position to a position engaged with the limiting member locking member 110 (limiting member locking mechanism), thereby stopping the rotation of the drive shaft 25 (shaft-shaped member). In addition, a pawl shaft 115 is integrally formed on each limiting member locking member 110 (limiting member locking mechanism), and the limiting member locking member 110 (limiting member locking mechanism) is mounted on the frame 12 by means of support bolts B1 (fastening members).

[0152] With this configuration, when the brake device 70 malfunctions and the drive shaft 25 (shaft-shaped member) accelerates to rotate, the retaining force of the retaining plate 130 (retaining mechanism) on the limiting member 140 is released by the inertial load of the retaining plate 130 (retaining mechanism). As a result, the limiting member 140 protrudes from a predetermined position toward a position where it engages with the limiting member locking member 110 (limiting member locking mechanism), thereby reliably stopping the rotation of the drive shaft 25 (shaft-shaped member).

[0153] Furthermore, the pawl shaft 115 is integrated with the limiting member locking member 110 (limiting member locking mechanism), which is mounted on the frame 12 using a support bolt B1 (fastening member). Therefore, its strength can be significantly improved compared to the installation strength when the pawl shaft 115 is mounted to the hole in the frame 12 by pressing or other methods.

[0154] In addition, in this embodiment, a pair of limiting member locking members 110 (limiting member locking mechanisms) are provided at different positions in the circumferential direction of the drive shaft 25 (shaft member), and a space is provided between one limiting member locking member 110 (limiting member locking mechanism) and the other limiting member locking member 110 (limiting member locking mechanism).

[0155] Thus, a space SP1 is provided between a pair of limiting member locking members 110 (limiting member locking mechanism), so that the limiting member locking members 110 can be made lighter compared to the case where the limiting member locking members (limiting member locking mechanism) are distributed around the entire periphery of the limiting member support member 120 and the retaining plate 130.

[0156] In this embodiment, the retaining mechanism has a circular retaining plate 130, which has a central hole 132 (bearing hole) supported by a shaft and capable of rotating about the axis of the drive shaft 25 (shaft member). The limiting member support member 120 and the retaining plate 130 are connected by a force-applying unit 150 (force-applying mechanism). The limiting member 140 has a limiting protrusion 141 protruding toward the retaining plate 130. The retaining plate 130 has a guide groove 136 that engages with the limiting protrusion 141 and holds the limiting member 140 at a predetermined radial position on the limiting member support member 120. The guide groove 136 has a first limiting wall 136b1 that engages with the limiting member 140 at a predetermined radial position, and a second limiting wall 136c1 that engages with the limiting member 140 at a position protruding outward from the predetermined radial position. The first limiting wall 136b1 is formed by an arc concentric with the central hole 132.

[0157] With this configuration, the retaining plate 130 (retaining mechanism) can rotate smoothly and coaxially with respect to the limiting member support member 120. Its simple construction allows for miniaturization of the rotational locking (cargo drop prevention) device 100. Furthermore, by assembling the limiting member 140, two retaining plates 130, and the force application unit 150 onto the limiting member support member 120, and connecting the two retaining plates 130 at a predetermined interval using the connecting member R1, modular assembly is achieved. Assemblies are also improved. Additionally, the bearing hole (center hole 132) is axially supported by the outer periphery of the bearing sleeve portion 122 of the limiting member support member 120, but it can also be directly axially supported by the drive shaft 25 (shaft-shaped member).

[0158] Furthermore, with this configuration, the retaining mechanism (retaining plate 130) can hold the limiting member 140 at a predetermined position in the limiting member storage portion 123 until a predetermined delay occurs in the retaining member support member 120, which rotates integrally with the driving shaft 25 (shaft-shaped member) that begins to rotate rapidly in the first rotational direction, or until the driving shaft 25 (shaft-shaped member) and the retaining mechanism (retaining plate 130) exceed a predetermined relative angle. Additionally, the length of the first limiting wall 136bl of the guide groove 136 can be freely set regardless of the size of the limiting member 140. Thus, if the limiting protrusion 141 moves only slightly within the guide groove 136, by using the first limiting wall 136bl to restrict the radial movement of the limiting protrusion 141, the limiting member 140 can be set to a state where it will not move towards the outer diameter side. Therefore, during idling operation, the operator's work of pulling the chain C1 in the winding direction will not be interrupted.

[0159] In addition, in this embodiment, a clearance groove 136b extending in the circumferential direction is formed on the retaining plate 130, the limiting protrusion 141 can move along the clearance groove 136b, and the first limiting wall 136bl is the wall surface on the outer diameter side of the clearance groove 136b.

[0160] With this configuration, the limiting protrusion 141 becomes a structure that slides within the clearance groove 136b extending in the circumferential direction. Therefore, by appropriately setting the length of the clearance groove 136b, the operating time of the rotary locking device 100 can be appropriately adjusted.

[0161] In addition, in this embodiment, a concave limiting member receiving portion 123 is provided on the limiting member support member 120 to receive the limiting member 140. The limiting member 140 is received in the limiting member receiving portion 123 when it does not protrude to the outer diameter side. On the inner side of the limiting member receiving portion 123, which is the inner diameter side of the drive shaft 25 (shaft member), an arc-shaped bottom surface 123b is provided. On the inner diameter side of the drive shaft 25 (shaft member), an arc-shaped side surface 143 of the limiting member 140, which engages with the limiting member receiving portion 123, is provided.

[0162] Thus, by providing an arc-shaped bottom surface 123b on the inner diameter side (inner side) of the limiting member housing 123, a stress concentration area will not form on the inner side of the limiting member housing 123. Therefore, the limiting member support member 120 will not break. Furthermore, by also providing an arc-shaped arc surface 143 on the limiting member 140, when the limiting member 140 collides with the locking wall 114, the sharp corner portion of the limiting member 140 will not collide with the side wall 123a inside the limiting member housing 123. Therefore, damage to the side wall 123a can be prevented.

[0163] In addition, in this embodiment, when the drive shaft 25 (shaft-shaped member) accelerates in the first rotation direction, the retaining plate 130 (retaining mechanism) resists the force of the force-applying unit 150 (force-applying mechanism) and rotates relative to the drive shaft 25 (shaft-shaped member) in a direction opposite to the first rotation direction, and the angle of the relative rotation exceeds a predetermined angle, the retaining plate 130 (retaining mechanism) holds the limiting member 140 at a predetermined position in the radial direction.

[0164] With this configuration, the rotary locking device 100 can be set to delay operation compared to the normal brake (brake device 70) of a lifting device such as a lever hoist 10. Therefore, according to the present invention, the rotary locking device 100 does not interfere with the operation of the normal brake (brake device 70) during normal use of a lifting device such as a lever hoist 10.

[0165] In addition, in this embodiment, the winch is a lever hoist 10, which includes: a load pulley 20 supported by a pair of frames 11 and 12 and around which a chain C1 for lifting goods is hung; a drive shaft 25 (corresponding to a shaft-shaped member) connected to the load pulley 20 via a reduction gear 30; and an operating lever 50, which drives the load pulley 20 to rotate in the winding and rewinding direction by operation.

[0166] With this configuration, even if the braking device 70 malfunctions, the lever hoist 10 can reliably prevent the goods from falling.

[0167] [Second Implementation]

[0168] Hereinafter, the rotation locking (cargo falling prevention) device 200 of the lever hoist 10 according to the second embodiment of the present invention will be described with reference to the accompanying drawings.

[0169] Figure 11 This is a cross-sectional view showing the structure near the rotary locking (cargo falling prevention) device 200 of the second embodiment. Figure 12 It means Figure 11 An exploded perspective view of the structure of the rotary locking (cargo falling prevention) device 200 shown. Figure 13 This indicates the structure of the rotary locking (cargo drop prevention) device 200 and is derived from... Figure 12 A decomposed 3D diagram showing the state when viewed from different angles.

[0170] like Figures 11 to 13 As shown, in this embodiment, a plate-shaped locking plate 210 is installed on the ratchet 80 side of the frame 12, and an insertion hole 211 is provided on the central side of the locking plate 210. The drive shaft 25, the limiting member support member 220, and the retaining plate 230 are inserted into the insertion hole 211.

[0171] Furthermore, on the locking plate 210, an inner protrusion 212 and a locking recess 213 are provided along the inner wall surface 211a of the through hole 211. The inner protrusion 212 is the portion that protrudes further inward than the locking recess 213. This inner protrusion 212 is positioned relative to the outer peripheral surfaces of the limiting member support member 220 and the retaining plate 230, which will be described later, with a slight gap. This results in a structure that does not hinder the rotation of the limiting member support member 220 and the retaining plate 230, which support the limiting member 240 in the retaining position. In this embodiment, two inner protrusions 212 are provided at 180-degree intervals in the circumferential direction.

[0172] Furthermore, the locking recess 213 is a portion located in the circumferential direction connected to the inner protrusion 212. In this embodiment, as... Figure 11As shown, the locking recess 213 is the portion between a pair of inner protrusions 212 in the inner wall surface 211a, and the circumferential length of the locking recess 213 is set to be relatively long. However, the circumferential length of the inner protrusions 212 may also be made longer than that of the locking recess 213. However, even when the circumferential length of the locking recess 213 is shortened, it is still necessary to have a length and depth for the limiting member 240 (described later) to enter the interior of the locking recess 213. The radius of the inner wall surface 211a where the locking recess 213 is located, from the axis of the drive shaft 25, is a fixed size, limiting the protrusion of the limiting member 240 within a specified range. Here, approximately one-third of the length of the limiting member 240 is allowed to protrude into the locking recess 213.

[0173] Additionally, a locking wall 214 is provided on the inner protrusion 212. The locking wall 214 protrudes into the locking recess 213 and serves to stop the rotation of the load pulley 20 by colliding with the limiting member 240, which rotates in one rotational direction (rewinding direction). Therefore, the locking wall 214 is shaped to prevent the limiting member 240 from being pushed back towards the rotation axis, and the side of the limiting member 240 is also shaped to prevent it from being pushed back due to collision with the locking wall 214.

[0174] In addition, in this embodiment, such as Figure 11 As shown, the inner wall surface 211a of the inner protrusion 212, opposite to the locking wall 214, is a tapered wall 215. The tapered wall 215 is a wall surface inclined radially. The locking wall 214 is located at the end of the drive shaft 25 of the locking recess 213 in the winding direction, and the tapered wall 215 is located at the end in the rolling direction. The tapered wall 215 is a wall surface used to push the limiting member 240 protruding into the locking recess 213 back from the locking recess 213 in the axial direction by rotating the drive shaft 25 in the rolling direction. Furthermore, the inner protrusion 212 and the locking recess 213 can be provided as one, or three or more. The tapered wall 215 corresponds to the engagement / disengagement wall. Alternatively, a locking wall can be provided instead of the tapered wall 215. In this case, even if the drive shaft 25 is rotated in the rolling direction, the limiting member 240 remains protruding into the locking recess 213, thereby limiting the rotation in the rolling direction by the locking wall.

[0175] Furthermore, the limiting member support member 220 of this embodiment is formed with a structure similar to that of the limiting member support member 120 in the first embodiment. Specifically, the limiting member support member 220 includes: a center hole 221, a bearing sleeve portion 222, a limiting member storage portion 223, and an insertion hole 224, which are the same as the center hole 121, the bearing sleeve portion 122, the limiting member storage portion 123, and the insertion hole 124 described above. This limiting member support member 220 is mounted on the drive shaft 25 at the center hole 221, thereby rotating integrally with the drive shaft 25. In addition, regarding the mounting of the limiting member support member 220 relative to the drive shaft 25, any method such as a locking screw, a key connection, or a spline connection can be used as long as the necessary torque can be transmitted.

[0176] Next, the retaining plate 230 will be described. The retaining plate 230, together with the retaining pin 250, constitutes a retaining mechanism. A circular rotating plate portion 231 is provided on the retaining plate 230, and a central hole 232 is provided at the radial center of this rotating plate portion 231. By inserting the bearing sleeve portion 222 into this central hole 232, the retaining plate 230 is supported so that it can rotate coaxially relative to the limiting member support member 220. Furthermore, the distance (i.e., radius) from the center of rotation to the outermost periphery of the retaining plate 230 is approximately the same as the distance to the outermost periphery of the limiting member support member 220. However, the radius of either the limiting member support member 220 or the retaining plate 230 may be set to be larger.

[0177] Alternatively, the retaining plate 230 may be a single piece that cantileveredly supports the retaining pin 250. However, under heavy loads, two retaining plates may be arranged with a limiting support member 220 between them. Furthermore, the retaining plates 230 may be connected to each other using a connecting member, and the two retaining plates 230 may each hold both ends of the retaining pin 250. Alternatively, the retaining pin 250 itself may connect the two retaining plates 230.

[0178] Furthermore, a peripheral wall portion 233 is erected on the outer periphery of the rotating plate portion 231. Moreover, the range of rotation relative to the limiting member support member 220 is defined by the rotating plate portion 231 and the peripheral wall portion 233 surrounding it. In the following description, this portion capable of rotating relative to the limiting member support member 220 is designated as a loose clearance fit portion 234. The peripheral wall portion 233 acts as a counterweight (weight) that increases the inertial load of the retaining plate 230. By providing the peripheral wall portion 233 on the outer periphery of the retaining plate 230, the thickness of the rotating plate portion 231 can be reduced, which contributes to overall miniaturization and weight reduction. The structure of this peripheral wall portion 233 is particularly effective when applied to shaft-shaped members rotating at low speeds.

[0179] Here, to define the rotation range of the limiting member support member 220, a first peripheral wall portion 233a is provided on the peripheral wall portion 233 to define one end of the rotation range, and a second peripheral wall portion 233b is provided to define the other end of the rotation range. However, the first peripheral wall portion 233a and the second peripheral wall portion 233b may also be integrally formed continuously. In addition, an opening portion 235 is provided between the first peripheral wall portion 233a and the second peripheral wall portion 233b to allow the limiting member support member 220 to be located therein. Therefore, the outer peripheral side of the limiting member support member 220 is configured to be able to rotate within a defined angle range when exposed through the opening portion 235.

[0180] Furthermore, in the holding state of the limiting member 240 (described later), the limiting member support member 220 abuts against the first peripheral wall portion 233a, which corresponds to the holding position. Additionally, when the limiting member support member 220 moves away from the first peripheral wall portion 233a, the holding position of the limiting member 240 is released, which corresponds to the holding release position. Furthermore, in order to configure the device to operate when the acceleration of the drive shaft 25 being targeted is very large, it is sometimes better to omit the peripheral wall portion 233.

[0181] Furthermore, the aforementioned limiting member storage portion 223 houses the limiting member 240. The limiting member 240 is housed in the limiting member storage portion 223 in a state where it can slide in the centrifugal direction from the storage position. A clearance portion 223b is provided on another side wall 223a of the limiting member storage portion 223. This clearance portion 223b is formed in a recessed manner from this side, and the retaining pin 250, described later, is located in the clearance portion 223b with clearance. A retaining recess 241 for engaging the retaining pin 250 with the limiting member 240 is provided on the side of the limiting member 240 facing the clearance portion 223b. By maintaining the engagement state between the retaining recess 241 and the retaining pin 250, the limiting member 240 is maintained in a predetermined position (storage position) within the limiting member storage portion 223.

[0182] In addition, such as Figure 11 As shown, with the movement limiting member 240 housed in a predetermined position within the movement limiting member housing 223, the outermost peripheral surface of the movement limiting member 240 is positioned relative to the center of the rotation axis at the same distance as the distance between the movement limiting member support member 220 and the center of the rotation axis. Furthermore, it is preferable that this distance is the same as the distance from the center of the rotation axis to the outermost peripheral surface of the retaining plate 230. Additionally, the size of the outer peripheral surface of the movement limiting member 240, which is far from the center of rotation, needs to be set in a manner that does not impede the rotation of the drive shaft 25.

[0183] In addition, such as Figure 11 and Figure 12As shown, a retaining pin 250 is mounted on the retaining plate 230. The retaining pin 250 is installed by inserting one end of it into a mounting hole 231a vertically formed on the hollow circular rotating plate portion 231 of the retaining plate 230. Therefore, the retaining pin 250 rotates integrally with the retaining plate 230. The retaining pin 250 maintains the state in which the limiting member 240 is housed in the limiting member housing portion 223 by being embedded in the aforementioned retaining recess 241. The retaining pin 250 moves within the clearance portion 223b in a manner that allows it to engage and disengage relative to the retaining recess 241. Therefore, the relative rotation of the retaining plate 230 relative to the limiting member support member 220 is limited according to the size of the gap between the retaining pin 250 in the clearance portion 223b and the limiting member support member 220, but as mentioned above, relative rotation can also be limited by the contact between the peripheral wall portion 233 and the limiting member support member 220.

[0184] In addition, the retaining pin 250 corresponds to a part of the retaining mechanism, which is integrated with the hollow circular plate-shaped rotating plate portion 231 and the peripheral wall portion 233.

[0185] Furthermore, in order to maintain the state in which the limiting member 240 is stored in the limiting member storage portion 223, and thus retain the pin 250 into the retaining recess 241, a force-applying unit 260 is provided on the rotation lock (cargo drop prevention) device 200. Additionally, as... Figure 11 As shown, in this embodiment, the force-applying unit 260 is disposed on the side opposite to the opening 235 in the loose clearance fit portion 234, but it can be disposed in any position as long as the movement limiting member 240 can be maintained in the state of being housed in the movement limiting member storage portion 223.

[0186] Furthermore, the force-applying unit 260 is configured with a structure similar to that of the force-applying unit 150 in the first embodiment described above. Specifically, the force-applying unit 260 has: a force-applying spring 261, which is the same as the force-applying spring 151, and a one-end retaining pin 262, which is the same as the one-end retaining pin 152. Moreover, the force-applying unit 260 has a other end retaining pin 263.

[0187] The other end locking pin 263 is installed by inserting into the mounting hole 231b formed on the rotating plate portion 231 of the retaining plate 230, and a component on the other end side of the force-applying spring 261 is fixed thereon.

[0188] Here, the point of action of the force-applying spring 261 engaged in one end of the locking pin 262 and the point of action of the force-applying spring 261 engaged in the other end of the locking pin 263 differ from the rotation center by a predetermined angle θ. Therefore, the force-applying spring 261 applies force in a manner that decreases this angle θ. Furthermore, this force is a force acting in the direction that causes the retaining pin 250 to abut against the retaining recess 241.

[0189] in addition, Figure 14 This diagram shows the state in which the limiting member 240 protrudes into the locking recess 213 and abuts against the locking wall 214, that is, the state in which the rotation locking device 200 operates to lock the rotation of the drive shaft 25. Figure 15 yes Figure 14 An enlarged schematic diagram of the area near the limiting member 240. (See attached diagram.) Figure 14 as well as Figure 15 As shown, an inclined surface 242 is provided at the lower end of the limiting member 240, which abuts against the retaining pin 250. The tangent L1 of the inclined surface 242 forms an angle α with respect to the side wall 223a. This angle α is preferably 45 degrees or about 45 degrees, but it can also be other inclined angles.

[0190] <Regarding its function>

[0191] In the rotary locking (cargo falling prevention) device 200 with the above structure, consider the following situation: that is, during the winding operation of the lever hoist 10, due to the failure of the brake device 70 or other reasons, the drive shaft 25 starts to accelerate in the winding direction under the tension applied to the chain C1 by the suspension load or the like.

[0192] Initially, due to the tension applied to chain C1, the drive shaft 25 and the limiting member support member 220, having lost their braking force, together with the limiting member 240, act as... Figure 11 A sharp increase in rotational speed occurs in one of the counterclockwise rotational directions (the direction of rotation). At this time, the force applied by the force spring 261 acts to make the retaining mechanism (retaining plate 230 and retaining pin 250) follow the rotation of the limiting member 240. However, due to the inertial force acting on the retaining mechanism (retaining plate 230 and retaining pin 250), the pressing force of the retaining pin 250 against the retaining recess 241 of the limiting member 240 is initially canceled out. When the drive shaft 25 further accelerates its rotation with the limiting member support member 220 and the limiting member 240 at an acceleration exceeding the followable acceleration, the retaining mechanism (retaining plate 230 and retaining pin 250) cannot follow its rotation, and the retaining pin 250 of the retaining mechanism (retaining plate 230 and retaining pin 250) begins to disengage from the retaining recess 241 of the limiting member 240. Furthermore, as the rotation continues to accelerate, the retaining pin 250 completely disengages from the retaining recess 241, and the engagement between the retaining pin 250 and the retaining recess 241 is released. The limiting member 240, having lost the retaining force of the retaining mechanism (retaining plate 230 and retaining pin 250), can protrude from the limiting member receiving portion 223 of the limiting member support member 220 toward the inner wall surface 211a of the locking plate 210. Moreover, a centrifugal mechanism, such as a spring (not shown), is not provided to apply force to the limiting member 240 in the centrifugal direction, or... Figure 11Instead of the centrifugal mechanism consisting of a spring as illustrated, the centrifugal mechanism slides in the centrifugal direction by the centrifugal force acting on the limiting member 240, so that the front end of the limiting member 240 enters the locking recess 213.

[0193] Thus, the limiting member 240 enters the locking recess 213. Moreover, after entering, the limiting member 240, supported by the limiting member support member 220, has one side colliding with the locking wall 214. As a result, the rotation of the limiting member support member 220 and the drive shaft 25 in one rotational direction (rewinding direction) is stopped, and the falling of the goods also stops.

[0194] In addition, after the drive shaft 25 stops as described above, the retaining pin 250 presses down on the rear end of the limiting member 240 to maintain the engagement between the limiting member 240 and the locking wall 214, so as to prevent the limiting member 240 from accidentally returning to the limiting member storage part 223.

[0195] On the other hand, consider the case where the brake device 70 is damaged and a lighter load is being lifted. In this situation, the resistance of the internal mechanism of the lever hoist 10 will prevent the load from falling sharply, but the rotational speed of the drive shaft 25 will gradually increase.

[0196] In this case, initially, due to the tension applied to chain C1, the drive shaft 25 and the limiting member support member 220, having lost their braking force, move together with the limiting member 240 in the winding direction (as...). Figure 11 The rotational speed increases in one direction (counterclockwise). At this time, the force applied by the force spring 261 causes the retaining mechanism (retaining plate 230 and retaining pin 250) to follow the rotation of the limiting member 240. Moreover, even if the limiting member 240 starts to accelerate along with the limiting member support member 220 and the drive shaft 25, but does not reach an acceleration exceeding the acceleration in the direction that causes the retaining mechanism to follow, the retaining mechanism (retaining plate 230 and retaining pin 250) follows its rotation, and the engagement between the retaining pin 250 and the retaining recess 241 is not released, continuing to retain. However, the pressing force of the retaining pin 250 against the retaining recess 241 of the limiting member 240 decreases due to the rotational acceleration.

[0197] Furthermore, if the rotational speed of the drive shaft 25 increases due to the continued acceleration of rotation, and the centrifugal force acting on the limiting member 240 exceeds the holding force generated by the pressing force of the holding pin 250 of the holding recess 241, then the limiting member 240 protrudes from the holding position toward the inner wall surface 211a. Moreover, the side of the limiting member 240 collides with the locking wall 214, and the limiting member support member 220 stops rotating together with the drive shaft 25.

[0198] Next, consider the normal operating state of the braking device 70. The lever hoist 10 typically includes a idling mechanism unique to it. With the idling mechanism engaged, the braking force of the braking device 70 is temporarily disabled, allowing the operator to adjust the length of chain C1 by hand-pulling it at a faster speed than when operating via a lever. However, for safety reasons, when the prescribed tension is applied in the winding direction, the braking device 70 activates, becoming a mechanism to stop the rotation of the drive shaft 25. On the other hand, since the braking device 70 with a ratchet 80 used in the lever hoist 10 does not brake in the winding direction, the length of chain C1 can be adjusted at a faster speed than in the winding direction. In this state, the rotation lock (cargo drop prevention) device 200 also operates as infrequently as possible in the winding direction (another rotation direction), resulting in good operability.

[0199] When the operator pulls chain C1 in the winding direction, the load pulley 20 rotates in the winding direction, and the drive shaft 25, the limiting member support member 220, and the limiting member 240 also rotate in the winding direction. At this time, the retaining recess 241 of the limiting member 240 presses the retaining pin 250 of the retaining mechanism in the winding direction, so the retaining force of the limiting member 240 does not decrease. Therefore, the retaining force of the limiting member 240 is different depending on the rotation direction of the drive shaft 25. That is, conditions such as the rotational speed of the drive shaft 25 when the limiting member 240 protrudes in the centrifugal direction from a predetermined position of the limiting member storage portion 223 can be set in the winding direction and the winding direction, respectively.

[0200] Figure 16 yes Figure 11 An enlarged schematic diagram of the vibrating member 240 is shown. The holding force that maintains the vibrating member 240 at a predetermined position on the vibrating member support member 220 is determined not only by the pressing force of the retaining pin 250, but also by the angle β formed by the tangent L2 between the side wall 223a of the vibrating member receiving portion 223 and the retaining recess 241 and the retaining pin 250. Specifically, when the angle β formed by the tangent L2 between the side wall 223a of the vibrating member 240 and the retaining recess 241 and the retaining pin 250 is 90 degrees or more, even with a small pressing force from the retaining pin 250, the vibrating member 240 will not protrude in the centrifugal direction. Furthermore, when the angle β formed by the side wall 223a and the tangent L2 is set to approximately 45 degrees, if a centrifugal force of equal or greater magnitude than the pressing force of the retaining pin 250 is applied, the vibrating member 240 will protrude in the centrifugal direction against the pressing force.

[0201] Therefore, in order to ensure that the rotary locking device 200 does not operate even when the rotational speed of the drive shaft 25 becomes high, but only operates when the rotational acceleration of the drive shaft 25 becomes above a predetermined value, the shape or positional relationship of the retaining pin 250 and the retaining recess 241 can be appropriately set such that the angle β formed by the sidewall 223a and the tangent L2 is 90 degrees or more. On the other hand, if it is desired that the rotary locking device 200 operates when the predetermined rotational speed is exceeded, the formed angle β is set to be less than 90 degrees, practically less than 75 degrees. In addition, the cross-sectional shape of the retaining pin 250 is as follows: Figure 11 and Figure 16 In the case of a circular shape, within the range of the depth of the retaining recess 241 to the radius of the retaining pin 250, the angle β varies with this depth, thus the retaining force varies. Furthermore, even if the angle β formed with the tangent L2 is 0 degrees, a retaining force can be obtained by selecting a structure that generates a specified frictional force.

[0202] like Figure 14 and Figure 16 As shown, the limiting member 240 is held in a manner protruding towards the outer diameter side by means of the inclined surface 242 and the force of the pressing force of the retaining pin 250. If the limiting member 240 is pressed in the axial direction with a force exceeding the pressing force, the limiting member 240 is pushed back. When the drive shaft 25 is rotated in the winding direction by the operating lever 50, the limiting member 240 moves away from the locking wall 214, and the front end of the limiting member 240 abuts against the tapered wall 215 located on the opposite side of the locking recess 213. When the drive shaft 25 is further rotated in the winding direction, the front end of the limiting member 240 is pressed by the tapered wall 215 and pushed back in the axial direction. During this period, the retaining pin 250 continues to press against the side wall of the limiting member 240. When the tangent point of the retaining pin 250 and the limiting member 240 moves toward the retaining recess 241, the limiting member 240 slides along the axial direction and is held in a predetermined position by the component of the pressing force of the retaining pin 250.

[0203] In addition, such as Figure 14 and Figure 15 As shown, the locking wall 214 is configured to be parallel to the side wall 223a of the limiting member storage portion 223 when it is in contact with the limiting member 240. Therefore, no component force is generated that pushes the limiting member 240 back in the axial direction due to the pressing force received from the locking wall 214.

[0204] <Regarding the effects>

[0205] With this configuration, the same effect as the rotation lock (cargo drop prevention) device 100 of the first embodiment described above can be achieved.

[0206] In addition, in this embodiment, the retaining plate 230 of the retaining mechanism has a circular plate-shaped rotating plate portion 231. The rotating plate portion 231 has a bearing hole (center hole 232) that is axially supported and can rotate about the axis of the drive shaft 25. The limiting member support member 220 and the rotating plate portion 231 are connected by a force-applying spring 261 (force-applying mechanism).

[0207] With this configuration, the retaining mechanism can rotate smoothly and coaxially with respect to the limiting member support member 220. Its simple construction enables miniaturization of the rotation locking (cargo drop prevention) device 200. Furthermore, assemblability is improved. Additionally, the bearing hole (center hole 232) is supported by the outer circumference of the bearing sleeve portion 222 of the limiting member support member 220, but it can also be directly supported by the drive shaft 25 (shaft-shaped member).

[0208] Furthermore, in this embodiment, the side of the movement limiting member 240 opposite to the side of the first rotation direction ( Figure 14 On the right side of the limiting member 240, a retaining recess 241 is provided that engages with the retaining pin 250. By adopting such a structure, the working threshold for protruding the limiting member 240 can be set more reliably and with higher precision than when retaining by the friction between the retaining pin 250 and the limiting member 240.

[0209] In addition, in this embodiment, the locking plate 210 (limiting member locking mechanism) has: an insertion hole 211 that allows the limiting member support member 220 to rotate freely about the axis of the drive shaft 25 (shaft-shaped member); a locking recess 213 that is recessed from the inner wall surface 211a of the insertion hole 211 toward the outer diameter side and allows the limiting member 240 protruding from the outer periphery of the limiting member support member 220 to enter; and a locking wall 214 that is provided at the end side of the locking recess 213 in the first rotation direction and stops the rotation of the drive shaft 25 (shaft-shaped member) by abutting against the limiting member 240.

[0210] With this configuration, it is easy to install onto the flat frame 12 that holds the drive shaft 25 (shaft-shaped member) in a rotatable manner. In addition, by arranging the movement limiting member support member 220 and the movement limiting member 240 in the through hole 211, the working part of the rotation locking (cargo falling prevention) device 200 can be reliably and easily isolated from the outside.

[0211] In addition, in this embodiment, the locking plate 210 (limiting member locking mechanism) has a tapered wall 215 (locking release wall) that gradually protrudes toward the axis as it faces the end side of the locking recess 213 in the second rotation direction, which is opposite to the first rotation direction. When the tapered wall 215 (locking release wall) is in contact with the limiting member 240, the limiting member 240 is pushed back from the protruding position by rotating the drive shaft 25 (shaft member) in the second rotation direction.

[0212] With this configuration, by simply rotating the drive shaft 25 (shaft-shaped member) in another rotational direction (rolling direction), the limiting member 240, which has temporarily moved from the predetermined position of the limiting member support member 220 in the centrifugal direction, can be pushed back to the predetermined position without disassembling the rotation lock (cargo drop prevention) device 200 (lever hoist 10).

[0213] <Variation Example>

[0214] The various embodiments of the present invention have been described above, but various modifications can be made to the present invention. These modifications will be described below.

[0215] In the above embodiments, the rotary locking (cargo falling prevention) device 100 was described as being applied to the lever hoist 10. However, the rotary locking (cargo falling prevention) device can also be applied to winches other than lever hoists, such as chain hoists, or to lifting devices with a fixed load direction similar to that of the lifting device.

[0216] Furthermore, in the first and second embodiments described above, for example, as Figures 7 to 9 ,as well as Figures 14 to 16 As shown, the structure is configured such that the limiting members 140 and 240 are movable in the circumferential direction relative to the retaining plates 130 and 230. Furthermore, the limiting member support members 120 and 220 and the retaining plates 130 and 230 are connected by force-applying units 150 and 260. However, the present invention is not limited to this structure. For example, as... Figure 17 and Figure 18As shown, the structure is formed as follows: retaining balls 133 and 252, such as iron balls, correspond to the retaining mechanism. Further, receiving recesses 125 and 225 are provided on the limiting member support members 120 and 220 to receive force springs 151 and 261 corresponding to the force-applying mechanism. The retaining balls 133 and 252, which are forceped by the force springs 151 and 261, engage with the retaining recesses 144 and 241 of the limiting members 140 and 240. Additionally, the limiting members 140 and 240 are always subjected to force on their outer diameter by the centrifugal force springs 160 and 270. Furthermore, protrusions 145 and 243 for preventing dislodgement are provided on the side of the limiting members 140 and 240 opposite to the retaining recesses 144 and 241. Furthermore, in the limiting member support members 120 and 220, at a position further outward than the central holes 121 and 221, there are anti-detachment recesses 126 and 226 that allow the protrusions 145 and 243 to enter and function as anti-detachment members. Additionally, regarding the retaining mechanism, besides iron balls such as retaining balls 133 and 252, it can also be a roller-shaped or prismatic or polygonal cross-section column.

[0217] Even with this configuration, similar to the aforementioned rotary locking (cargo drop prevention) devices 100 and 200, when the drive shaft 25 (shaft-shaped member) rotates in one direction exceeding a predetermined acceleration, the rotary locking (cargo drop prevention) devices 100 and 200 activate, thereby stopping the rotation. Furthermore, even if the limiting member 140 protrudes outwards, the protrusion 145 will not detach from the anti-detachment recess 126, thus preventing the limiting member 140 from detaching from the limiting member storage portion 123. Therefore, it is no longer necessary to arrange the limiting member locking member 110 on the entire circumference of the limiting member support member 120 to prevent the limiting member 140 from detaching from the limiting member storage portion 123. Therefore, the limiting member locking member 110 can be configured, for example, to have a pair, and a large space SP1 can be formed between such a pair of limiting member locking members 110. Furthermore, it is possible to achieve a lightweight design for the pair of limiting member locking members 110.

[0218] Furthermore, an example is shown where the rotary locking (cargo falling prevention) devices 100 and 200 are arranged on the drive shaft of the winch, but their installation position is not limited to the drive shaft. For example, the rotary locking (cargo falling prevention) devices 100 and 200 can be arranged on a shaft-like member that rotates integrally with the rotating member being targeted, such as the shaft of a load pulley or drum. Therefore, even if the deceleration mechanism or the like is damaged, cargo falling can be prevented.

[0219] Figure 19 This diagram illustrates a variation related to the engagement method between the retaining pin 250 and the limiting member 240. Additionally, Figure 20 It means from Figure 19The diagram shows the state in which the limiting member 240 protrudes and engages with the locking wall 214. Figure 19 In the shown configuration, the retaining pin 250 is positioned to cover the front end of the limiting member 240. From this position, when the limiting member support member 220 rotates rapidly in the rewind direction, the retaining pin 250 cannot follow and remains, thus releasing its engagement with the front end face of the limiting member 240. The limiting member 240 can then protrude into the locking recess 213. Furthermore, as... Figure 20 As shown, when the limiting member 240 protrudes, the locking wall 214 and the limiting member 240 engage to lock the rotation. At this time, the retaining pin 250, through the force of the force application unit 260, engages with the return restriction recess 253 formed on the side of the protruding limiting member 240, thereby preventing the unintentional return of the limiting member 240.

[0220] Figure 21 This is the front view showing a variation of the retaining mechanism. Figure 22 yes Figure 21 The side sectional view of the retaining mechanism is shown. Figure 21 and Figure 22 In the structure shown, two retaining plates 230 are provided, which are used to clamp the limiting member support member 220 and the limiting member 240 in between. In addition, the two retaining plates 230 are connected by a connecting member R1, and the two retaining plates 230 are integrally connected by the connecting member with a predetermined interval.

[0221] In addition, such as Figure 22 As shown, the two ends of the retaining pin 250 are supported by two retaining plates 230. The two retaining plates 230 are rotatably supported on the outer periphery of the bushing portion 227 of the limiting member support member 220. The limiting member support member 220 and the retaining plates 230 are connected by a force-applying unit 260, which applies a force to the retaining plates 230 to rotate them relative to the limiting member support member 220 in the rotational direction. That is, when the limiting member support member 220 rotates in the rotational direction, the retaining plates 230 are subjected to a force by the force-applying unit 260 in the direction following its rotation. Alternatively, the retaining pin 250 and the connecting member R1 can be integrated, but... Figure 21 and Figure 22 In the structure shown, the retaining pin 250 and the connecting structural member R1 are separate components. Furthermore, there are four connecting structural members R1. Alternatively, the retaining pin 250 and the other end locking pin 263 can also function as connecting structural members R1.

[0222] The braking device used in lever hoists or chain hoists consists of a braking device 70 comprising a ratchet 80 and a pawl member 90. This braking device 70 applies braking force only in the winding direction; however, within a predetermined angle (tooth pitch angle) determined by the number of teeth 83 of the ratchet 80, the braking force is not applied, and the device idles and winds back. Therefore, when a rotary locking device 200 is mounted coaxially with the braking device 70, there is a possibility that the rotary locking device 200 will engage earlier than the braking device 70. However, the rotary locking device 200 is an emergency brake and is not recommended to operate it normally. Therefore, in Figure 21 and Figure 22 In the modified example shown, the rotary locking device 200 operates after the braking device 70.

[0223] That is, if the operation is interrupted during the lifting process, the ratchet 80 will rotate freely in the return direction by a maximum angle (tooth pitch angle) obtained by dividing one revolution by the number of teeth. This angle is set as... Figure 21 The angle γ is shown. In this case, the preferred configuration is that the rotation locking device 200 also operates with a delay greater than angle γ. Therefore, in the retracted state of the limiting member 240, the depth of the retaining recess 241 that engages with the retaining pin 250 is increased by at least angle γ. Moreover, it is preferable that the retaining member 240 is maintained by rotating relative to the limiting member support member 220 at an angle greater than angle γ, relative to the drive shaft 25 and the limiting member support member 220, in a second rotational direction opposite to the winding direction.

[0224] The retaining recess 241 of the limiting member 240 is determined by the trajectory of the retaining pin 250, but the inner wall of the outer periphery of the retaining recess 241 is provided with a predetermined gap relative to the trajectory, making manufacturing easier. Here, in order to delay the operation of the rotary locking device 200 compared to the braking device 70, instead of adjusting based on the depth of the retaining recess 241, the adjustment can be made by the spring pressure of the force-applying spring 261 of the force-applying unit 260. The delay is achieved by increasing the spring pressure of the force-applying spring 261, but under low load conditions, the range of operation will not increase even if the braking device 70 fails. Therefore, it is preferable to adjust using the depth of the retaining recess 241 (the angle formed by the depth of the retaining recess 241 about the axis of the drive shaft 25).

[0225] Alternatively, in the first embodiment, it can be omitted. Figures 5 to 10The guide groove 136 in the middle allows the retaining protrusion 137, which has a first limiting wall and a second limiting wall, to protrude from the retaining plate 130 toward the limiting member 140 side, and the movement of the limiting member 140 is controlled by engaging with the limiting protrusion 141. In this case, instead of the inner sidewall 136a1, a relative rotation limiting protrusion is added to the retaining plate to limit the relative rotation between the limiting member support member 120 and the retaining plate 130 within a specified range. In addition, the inner wall surface 111a of the limiting member locking member 110 can be used to limit the protrusion of the limiting member 140 in the centrifugal direction.

[0226] Additionally, although the effect is limited, it can also be construed as: omission. Figures 5 to 10 The return limiting slot 136c in the middle is replaced by having Figure 17 The centrifugal force spring 160 shown prevents the limiting member 140 from returning to its original position after the rotation locking device is activated. Alternatively, depending on the specifications of the lifting device that mounts the rotation locking device, the return limiting groove 136c can be omitted without adding the centrifugal force spring 160. Alternatively, it can be configured to include the return limiting groove 136c but omit the second limiting wall 136c1. Instead of the inclined wall 136c1, the second limiting wall 136c1 can be an arc-shaped wall centered on the axis of the drive shaft 25, such as the clearance groove 136b, or a combination of an inclined wall and an arc-shaped wall.

[0227] In addition, although the illustration is omitted, a guide groove may be provided on the side of the movement limiting member 140, and a guide pin that engages with the guide groove may be provided on the side of the retaining plate 130.

[0228] Preferably, the limiting member support member 120 is held by two retaining plates 130, but it can also be configured such that only one retaining plate 130 is arranged adjacent to the limiting member support member 120.

[0229] Preferably, the limiting member support members 120 and 220 are held by two retaining plates 130 and 230, but it can also be configured such that only one retaining plate 130 and 230 is arranged adjacent to the limiting member support members 120 and 220.

[0230] Alternatively, it can be configured such that when the limiting members 140 and 240 collide with the locking walls 114 and 214, the limiting members 140 and 240 fall down. Figure 21 An example of such a configuration is shown. Additionally, Figure 21 The diagram shows the application of the rotary locking device 100 in the first embodiment, but it can also be applied to the rotary locking device 200 in the second embodiment. Figure 23 A variation of the invention is shown in which an inclined wall 127 is provided near the opening of the limiting member receiving portion 123, and a view of the guide groove 136 is shown in perspective. Figure 23In the structure shown, on one side of the opening of the limiting member storage section 123 ( Figure 23 The left side (clockwise) is provided with an inclined wall 127 that is radially inclined relative to the limiting member support member 120.

[0231] In this structure, when the limiting member 140 collides with the locking wall 114, the limiting member 140 rotates clockwise (tilts) around the limiting protrusion 141. Furthermore, the limiting member 140 collides with the inclined wall 127, thereby stopping the rotation of the limiting member 140. At this time, the limiting member 140 is sandwiched between the corner 114a of the locking wall 114 and the inclined wall 127. At this time, the limiting member 140 applies a force in the direction of arrow A to the inclined wall 127. The direction of this force (arrow A) is inclined relative to the circumferential direction of the limiting member support member 120. Therefore, the force along the circumferential direction does not act on the wide plate portion 120b.

[0232] Here, from Figure 4 It is clearly known that the circumferential thickness of the wide sheet 120b is greater than that of the other sheet. Figure 23 The dimension in the direction of arrow A is small. Therefore, even if the limiting member 140 collides with the locking wall 114, due to the presence of the inclined wall 127, the direction of the force applied to the wide plate portion 120b changes from the circumferential direction to the direction of arrow A. Therefore, the impact strength of the limiting member support member 120 when it collides with the locking wall 114 relative to the limiting member 140 can be improved.

[0233] Furthermore, in the first embodiment described above, the limiting member support member 120 has an arc-shaped bottom surface 123b, and the limiting member 140 has an arc-shaped surface 143 corresponding to the arc-shaped bottom surface 123b. However, the limiting member support member 120 may have a square bottom surface in addition to the arc-shaped bottom surface 123b, or the corner portion of the square bottom surface may be formed into an R-shaped intermediate shape. Additionally, the arc-shaped surface 143 corresponding to the arc-shaped bottom surface 123b may also have a square surface, or the corner portion of the square surface may be formed into an R-shaped intermediate shape.

[0234] Furthermore, the structure of the rotary locking (cargo falling prevention) device 100 of the first embodiment can be applied to the rotary locking (cargo falling prevention) device 200 of the second embodiment, and conversely, the structure of the rotary locking (cargo falling prevention) device 200 of the second embodiment can be applied to the rotary locking (cargo falling prevention) device 100 of the first embodiment. For example, in the rotary locking (cargo falling prevention) device 200 of the second embodiment, the locking plate 210 can be replaced by a pair of limiting member locking members 110 (members with pawl shafts 115) of the rotary locking (cargo falling prevention) device 100 of the first embodiment. Additionally, in the rotary locking (cargo falling prevention) device 100 of the first embodiment, the locking plate 210 of the rotary locking (cargo falling prevention) device 200 of the second embodiment can be used instead of the pair of limiting member locking members 110.

[0235] (Symbol Explanation)

[0236] 10…Lever hoist, 11, 12…Frame, 12a…Through hole, 12b…Shaft hole, 13…Housing, 14…Brake cover, 14a…Flange, 14a1…Through hole, 15…Lock cover, 15a…Standing part, 15b…Opposite surface, 15b1…Through hole, 20…Load pulley, 20a…Through hole, 21…Load gear, 25…Drive shaft (corresponding to shaft-shaped component), 26…Male thread, 27…Pinary gear, 30…Reduction gear, 31…Large diameter gear, 32…Small diameter gear, 34…Gearbox, 35…Female thread component, 36…Female thread, 37…Switching gear, 40…Switching pawl, 45…Switching knob, 50…Operating lever, 55…Cam component, 60…Freewheel handle, 70…Brake Device, 71…brake bracket, 71a…flange, 71b…hollow bushing, 72a, 72b…brake plate, 80…ratchet (corresponding to a part of the ratchet mechanism), 83…rabbit tooth, 90…pawl member (corresponding to a part of the ratchet mechanism), 91…pawl shaft, 92…bulb, 93…torsion spring, 93a…coil, 100, 200…rotary locking (cargo drop prevention) device, 110…limiting member locking member (corresponding to the limiting member locking mechanism), 111…mounting hole, 111a…inner wall surface, 112, 212…inner protrusion, 113…recess, 114, 214…locking wall, 114a…corner, 115…pawl shaft (corresponding to a part of the ratchet mechanism), 116…rib, 1 20, 220…Limiting component support member, 120a…Narrow plate section, 120b…Wide plate section, 121, 221…Center hole, 122, 222…Bearing sleeve section, 123, 223…Limiting component storage section, 123a, 223a…Side wall, 123b…Arc bottom surface, 124, 224…Insertion hole, 125, 225…Storage recess, 126, 226…Anti-detachment recess, 127…Inclined wall, 130, 230…Retaining plate (corresponding to a part of the retaining mechanism), 131…Hole section, 132, 232…Center hole, 133, 252…Retaining ball (corresponding to the retaining mechanism), 136…Guide groove, 136a…Allowable groove section, 136a1…Inner side wall, 136b…Clearance groove section, 1 36b1…First limiting wall, 136c…Return limiting groove, 136c1…Second limiting wall, 137…Retaining protrusion, 137a…Front end of protrusion, 140, 240…Limiting member, 141…Limiting protrusion, 142…Outer peripheral surface, 143…Arc surface, 144, 241…Retaining recess, 145…Protrusion, 150, 260…Force application unit (corresponding to force application mechanism), 151, 261…Force application spring, 152, 262…One-end locking pin, 160, 270…Centrifugal force application spring, 210…Locking plate (corresponding to limiting member locking mechanism), 211…Through hole, 211a…Inner wall surface, 213…Locking recess, 215…Conical wall, 223b…Clearance, 227…Sleeve portion,231…Rotating plate portion, 231a, 231b…Mounting holes, 233…Peripheral wall portion, 233a…First peripheral wall portion, 233b…Second peripheral wall portion, 234…Loose clearance fit portion, 235…Opening portion, 242…Inclined surface, 243…Protrusion, 250…Retaining pin, 253…Return limiting recess, 263…Other end locking pin, B1…Support bolt (corresponding to fastening member), B1a…First step portion, B1b…Second step portion, B1c…Male thread portion, C1…Chain, N1…Nut, R1…Connecting structural member, S1…Clearance, SP1…Space, W…Washer.

Claims

1. A rotational lock device characterized by comprising: a stopper support member installed on a shaft member and rotating integrally with the shaft member, a stopper member supported on the stopper support member in a state of being slidable from the shaft center side of the shaft member toward the outside, a holding mechanism that holds the stopper member at a prescribed position of the stopper support member, a force applying mechanism that applies a force to the holding mechanism relative to the stopper member toward a first rotational direction that is one rotational direction, and a stopper engagement mechanism that stops the rotation of the shaft member by engaging with the stopper member; when the shaft member is accelerated in rotation toward the first rotational direction, the holding force of the holding mechanism on the stopper member is reduced and / or released by the inertial load of the holding mechanism, whereby the stopper member protrudes from the prescribed position to a position engaged with the stopper engagement mechanism, thereby stopping the rotation of the shaft member.

2. The rotational lock device according to claim 1, characterized in that the holding mechanism has a circular plate-shaped holding plate and a holding pin; the holding plate has a bearing hole supported by a shaft so as to be rotatable with the shaft center of the shaft member as a center, and the stopper support member and the holding plate are linked by the force applying mechanism.

3. The rotational lock device according to claim 2, characterized in that a holding recess that engages with the holding pin is provided on the side of the stopper member opposite the side of the first rotational direction.

4. The rotational lock device according to claim 1, characterized in that the stopper engagement mechanism has: a through hole that allows the stopper support member to rotate freely around the shaft center of the shaft member; an engagement recess recessed from the inner wall of the through hole toward the outer diameter side, and into which the stopper member protruding from the outer periphery of the stopper support member enters; and an engagement wall provided on the end portion side of the first rotational direction in the engagement recess, and that stops the rotation of the shaft member by abutting against the stopper member.

5. The rotational lock device according to claim 4, characterized in that the stopper engagement mechanism has an engagement release wall that gradually protrudes toward the shaft center as it goes toward the end portion side of a second rotational direction opposite the first rotational direction in the engagement recess; and the stopper member is pushed back from the protruding position by rotating the shaft member in the second rotational direction in a state where the engagement release wall abuts against the stopper member.

6. The rotational lock device according to claim 1, characterized in that the holding mechanism has a circular plate-shaped holding plate; the holding plate has a bearing hole supported by a shaft so as to be rotatable with the shaft center of the shaft member as a center; the stopper support member and the holding plate are linked by the force applying mechanism; the stopper member has a stopper protrusion protruding toward the holding plate; and the stopper protrusion is engaged with the engagement wall of the stopper engagement mechanism. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The retaining plate has a retaining protrusion that engages with the limit protrusion and retains the limit member at a prescribed position in the radial direction of the limit member support member; The retaining protrusion has a first limit wall that engages with the limit member at the prescribed position in the radial direction and a second limit wall that engages with the limit member at a position that protrudes outward from the prescribed position in the radial direction.

7. The rotational lock device according to any one of claims 3 to 6, wherein when the shaft-like member is accelerated in the first rotational direction, the retaining mechanism relatively rotates in a direction opposite to the first rotational direction with respect to the shaft-like member against the force of the force applying mechanism; the retaining mechanism retains the limit member at a prescribed position in the radial direction until the angle of the relative rotation exceeds a prescribed angle.

8. The rotational lock device according to any one of claims 1 to 6, wherein the shaft-like member is integrally linked to a load sheave on which a chain is hung.

9. A hand chain hoist comprising: a load sheave supported by a pair of frame shafts and on which a chain for hoisting a load is hung, a drive shaft connected to the load sheave via a reduction gear, a brake device attached to the drive shaft, and an operation lever that, by being operated, rotates the load sheave in a winding and unwinding direction; the hand chain hoist characterized in that on the outer periphery of the drive shaft, the rotational lock device according to any one of claims 1 to 8 is disposed; the shaft-like member is the drive shaft; the limit member locking mechanism is attached to the frame.

10. The hand chain hoist according to claim 9, wherein in the rotational lock device, when the shaft-like member is accelerated in the first rotational direction, the retaining mechanism relatively rotates in a direction opposite to the first rotational direction with respect to the shaft-like member against the force of the force applying mechanism, the retaining mechanism retains the limit member at a prescribed position in the radial direction until the angle of the relative rotation exceeds a prescribed angle; the brake device has a ratchet wheel having a plurality of ratchet teeth; the drive shaft has the rotational lock device; the prescribed angle is an angle obtained by dividing one revolution of the ratchet wheel by the number of teeth of the ratchet teeth.

11. A hoist having a frame that is plate-like, the hoist characterized in that a brake device and a rotational lock device are provided, the brake device has a ratchet mechanism that has a ratchet wheel attached to the periphery of a shaft-like member and having ratchet teeth on the outer periphery side, a pawl member that engages with the ratchet teeth, and a pawl shaft that axially supports the rotation of the pawl member, and, by the engagement of the ratchet teeth with the pawl member, the ratchet wheel is allowed to rotate in the winding direction but is not allowed to rotate in the unwinding direction, the rotational lock device locks the abrupt rotation of the shaft-like member; the rotational lock device has: a limit member support member attached to a shaft-like member and rotating integrally with the shaft-like member, a stopper member supported to the stopper support member in a state of being slidable from the shaft center side of the shaft member toward the outside, a holding mechanism that holds the stopper member at a prescribed position of the stopper support member, a force applying mechanism that applies a force to the holding mechanism in a direction of the return direction with respect to the stopper member, and a stopper locking mechanism that stops the rotation of the shaft member by abutting against the stopper member; when the shaft member is accelerated in the return direction, the holding force of the holding mechanism on the stopper member is released by the inertial load of the holding mechanism, and thus the stopper member is projected from the prescribed position to a position engaged with the stopper locking mechanism, thereby stopping the rotation of the shaft member.

12. The hoist according to claim 11, wherein the pawl shaft is formed integrally on each of the stopper locking mechanisms; the stopper locking mechanisms are attached to the frame by fastening members.

13. The hoist according to claim 11, wherein a pair of the stopper locking mechanisms are provided at different positions in the circumferential direction of the shaft member, and a space is provided between one of the stopper locking mechanisms and the other of the stopper locking mechanisms.

14. The hoist according to any one of claims 11 to 13, wherein the holding mechanism has a holding plate in a circular plate shape; the holding plate has a bearing hole supported by a shaft so as to be rotatable about the shaft center of the shaft member; the stopper support member and the holding plate are linked by the force applying mechanism; 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 prescribed position in the radial direction of the stopper support member; the guide groove has a first restriction wall that engages with the stopper member at the prescribed position in the radial direction, and a second restriction wall that engages with the stopper member at a position projecting outward from the prescribed position in the radial direction; the first restriction wall is formed by a circular arc concentric with the bearing hole.

15. The hoist according to claim 14, wherein a play groove portion extending in the circumferential direction is formed in the holding plate, and the stopper projection is movable along the play groove portion, and the first restriction wall is an outer diameter side wall surface in the play groove portion.

16. The hoist according to any one of claims 11 to 13, wherein a concave stopper receiving portion that receives the stopper member is provided in the stopper support member, and the stopper member is received in the stopper receiving portion when not projecting outward in the radial direction; a circular arc-shaped circular arc bottom surface is provided on the inner side of the stopper receiving portion as the inner diameter side of the shaft member, and a circular arc surface is provided on the inner diameter side of the shaft member, and the side surface shape of the stopper member engaged with the stopper receiving portion is circular arc-shaped.

17. The hoist according to any one of claims 11 to 13, wherein The holding mechanism holds the limit member at a prescribed position in the radial direction until the angle of the relative rotation exceeds a prescribed angle.

18. The hoist according to any one of claims 11 to 13, wherein the hoist is a hand-operated hoist having: a load sheave supported by a pair of the frame shafts and having a chain for hoisting a load wound therearound, a drive shaft connected to the load sheave via a reduction gear and corresponding to the shaft-like member, and an operating lever for rotating the load sheave in the winding and unwinding directions by being operated.

19. The hoist according to claim 18, wherein the operating lever is provided with a handle portion to be gripped by a hand of an operator, and a lever portion to be operated by the hand of the operator, and the lever portion is provided with a cam portion to be engaged with a cam groove formed in the drive shaft, and a notch portion to be engaged with a notch formed in the drive shaft.

20. The hoist according to claim 19, wherein the cam groove is formed in the drive shaft so as to be engaged with the cam portion of the lever portion when the operating lever is operated to rotate the load sheave in the winding direction, and the notch is formed in the drive shaft so as to be engaged with the notch portion of the lever portion when the operating lever is operated to rotate the load sheave in the unwinding direction.

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