JPH086000Y2 - Locking device for limit switch and gear unit for crane lift detection - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial application] The present invention relates to a lock device for a limit switch and a gear unit for detecting the lifting height of a crane. More specifically, when replacing a wire rope that suspends a hook, the upper and lower limit positions of the hook, etc. The detection gear for detecting the wire rope can be locked so as not to idle after being removed from the pinion that rotates in conjunction with the winch drum for winding the wire rope.After replacing the wire rope, the hook position and limit switch operating position The present invention relates to a lock device for a detection gear that is capable of reliably reproducing the relationship with

[0002]

2. Description of the Related Art A main winding wire rope for a club-type overhead crane installed in a steel factory or the like is wound around a winch drum of a crane in order to elevate and lower a main hook for hanging a ladle or the like. And
For example, each pinion of the main winding head detection device consisting of two units,
It is designed to be rotated simultaneously with the winch drum via the pinion shaft. In the meantime, the detection gear integrated with the pinion and the limit switch is also rotated, and the limit switch is operated by the detection shaft protruding from the detection gear to detect the lifting stop position of the hook. The limit switch has, for example, a switch unit that detects four height positions, and converts the rotation of the detection shaft into a rotational movement of a worm wheel via a worm gear in the limit switch. The worm wheel moves within 360 degrees, and one of the four contact points is operated by a cam mounted around the wheel axis, which causes the wire rope to wind up or wind up, and further to prevent the hot metal. It is set so that it can detect a fixed work position above and below the ladle for transferring to the converter and issue a signal for stopping the rotation of the winch drum each time.

The wire rope of such a crane needs to be regularly replaced in order to ensure safety. Conventionally, the main winding wire rope in a club-type overhead crane installed in a steelmaking factory or the like has been replaced as follows. As shown in FIG. 7, the winch drums 1A and 1B of the crane 30 are rotated, the wire ropes 11A and 11B wound around them are unwound, and the ladle 13
The main hooks 14, 14 for hanging the etc. are lowered to a predetermined height position. Along with the lowering, the pinion shaft 2a integrated with each pinion 2 (see FIG. 8) of the two main winding head detecting devices 20A and 20B as shown in FIG. 3 is rotated simultaneously with the winch drums 1A and 1B. The detection gear 3 meshing with the pinion 2 is also rotated. And the detection axis 3a
The worm wheel built in the limit switch 5 that is integrated with the detection gear 3 is also rotated. When the descent is stopped, the worm wheel also stops moving and the limit switch 5 is placed in that state. Next, the connection bolts 21 and 21 of the gear case 4 that covers the pinion 2 and the detection gear 3 are removed, and the upper cover 4A is removed from the lower cover 4B. The mounting bolts 22, 22 fixing the limit switch 5 to the switch base 19 are also removed, and the limit switch 5 is removed from the switch base 19. Then, the mounting bolts 23, 23 fixing the lower cover 4B are also removed, and the detection gear 3 and the limit switch 5 integrated with the lower cover 4B are pulled out to the front. After that, if the detection gear 3 rotates by any chance, the worm wheel of the limit switch 5 is also rotated, and when the detection gear 3 is subsequently meshed with the pinion 2, the relationship between the pinion 2 and the worm wheel is broken. It will be. Therefore, the detection gear 3 is tied together with the limit switch 5 with a rope or a wire so that the detection gear 3 does not idle, and is stored on the floor surface 12a close to the winch drums 1A and 1B. Old wire rope 11
A new wire rope is connected to the tips of A and 11B, the winch drums 1A and 1B are rotated, and the new wire rope is pulled up by the winch drums 1A and 1B while winding the old wire rope. When the new wire rope 11 is replaced with the winch drum 1, the winch drums 1A and 1B are rotated to adjust the payout amount or the winding amount of the wire ropes 11A and 11B so that the new wire rope 11 is at the position where it was originally lowered. Finally, the limit switch 5 and the detection gear 3 are returned to their original positions so as to mesh with the pinion 2 to release the fixed state of the wire rod. The lower cover 4B is fixed with the mounting bolts 23, and the limit switch 5 is attached to the switch base 19 and the upper cover 4A is attached to the lower cover 4B with the mounting bolts 22 and the connection bolts 21. According to such a procedure, when the pinion 2 and the detection gear 3 are meshed with each other, the detection gear 3 can be meshed with the pinion 2 without changing the rotation posture, and the wire ropes 11A and 11B can be replaced. Even after the rotation, the internal state of the limit switch 5 can be maintained by the rotation of the detection gear 3, the previous relationship between the pinion 2 and the worm wheel is reproduced, and the subsequent operation of the switch portion is prevented from being misaligned. .

[0004]

[Problems to be solved by the invention] By the way, the upper cover 4
In order to remove A, the eight connecting bolts 21 are used. To remove the limit switch 5, the detection gear 3 integrated therewith, and the lower cover 4B, the three mounting bolts 2 are also used.
Two and four mounting bolts 23 have to be removed.
Therefore, the disassembling work in the two main hoist lift detecting devices 20 involves, for example, the work of removing and attaching 30 bolts, which requires a great deal of labor and takes a very long time. In addition, the detection gear 3 that has been removed must be tied with ropes or wires so as not to run idle, which complicates the work. If the fastening is not perfect, the detection gear 3 will slip a little and the limit switch 5 will be displaced. by this,
There is a problem in that the detection position after the assembly is distorted and the readjustment thereof requires a great deal of trouble. The present invention has been made in view of the above problems, and its purpose is to remove and reassemble a switch gear unit and a gear case including a limit switch and a detection gear when replacing a wire rope of a crane. Eliminates the need to replace the wire rope and reduces the work time, and prevents the detection gear from idling reliably, and the limit switch ensures the correct lifting position of the hook after the wire rope is replaced. To be able to detect
(EN) Provided is a lock device for a limit switch / gear unit for lifting height detection of a crane, which realizes a change in a meshing relationship between a detection gear and a pinion.

[0005]

The present invention provides a pinion that rotates in conjunction with a winch drum for winding a wire rope of a crane, a detection gear that meshes with the pinion, and a gear case that covers the pinion and the detection gear. A limit switch that supports the detection shaft that extends from the detection gear in parallel with the pinion shaft and protrudes, and detects that the wire rope has reached a predetermined feeding amount or winding amount based on the rotation of the detection shaft. It is applied to the crane head detection device. The feature is that, with reference to FIG. 1, a space where the detection gear 3 and the pinion 2 are disengaged from each other in the gear case 4 and the detection gear 3 can be displaced in a direction away from the pinion 2. 6 is secured. A switch base 8 that movably supports a switch base 5A of the limit switch 5 is provided in order to displace the switch gear unit 7 in which the limit switch 5 and the detection gear 3 are integrated. The inner surface 4c of the gear case 4 is provided with a locking body 9 that engages with the detection gear 3 when the space 6 is displaced from the pinion 2 and reaches a predetermined distance S, and prevents the detection gear 3 from idling. The switch base 8 is formed with a slide groove 8a longer than the switch base 5A and capable of displacing the switch base 5A. A spacer 10 having a length equal to the predetermined distance S is interposed between the switch base 5A and the end of the slide groove 8a, and the switch base 5A and the one end 8m of the slide groove 8a.
The spacer 10 is replaceably fixed between the switch base 5A and the other end 8n of the slide groove 8a.

[0006]

[Operation] Wire ropes 11A and 11B of the crane 30
When replacing, the main hook 14 is first lowered to a predetermined height position of, for example, 1 m from the factory floor and stopped. At the predetermined position, with the pinion 2 and the detection gear 3 of the lift detecting device 20 meshing with each other, the spacer 10 interposed on the other end 8n side of the slide groove 8a of each switch base 8 is removed. The limit switch 5 attached to the switch base 5A is displaced together with the detection gear 3 to separate the detection gear 3 from the pinion 2. The detection gear 3 is displaced by a predetermined distance S without rotating, and meshes with the locking body 9 formed on the inner surface 4c of the gear case 4. The detection gear 3 that has been disengaged from the pinion 2 is restrained again. As a result, the state of the switch section in the limit switch 5 is prevented from changing thereafter. Put the pulled out spacer 10 in the reverse posture,
The slide groove 8a is fixed by inserting it in the gap formed between the one end 8m and the switch base 5A (see FIG. 2). The detection gear 3 integrated with the limit switch 5 and the switch base 5A is held in a state of being meshed with the locking body 9. The new wire rope is connected to the tips of the old wire ropes 11A and 11B, and the winch drums 1A and 1B are rotated to pull up the new wire ropes while winding the old wire ropes 11A and 11B. When the new wire rope 11 is replaced, the hanging length of the wire rope 11 is adjusted so that the main hook 14 is located at a predetermined height position on the floor surface. The spacer 10 interposed at the one end 8m of the slide groove 8a is removed, the switch gear unit 7 and the switch base 5A are moved to their original positions, and the detection gear 3 is meshed with the pinion 2. The spacer 10 is inserted and fixed between the other side 8n of the slide groove 8a and the switch base 5A (see FIG. 1). During this time, the switch portion of the limit switch 5 maintains the previous state in which the predetermined position of the main hook 14 is detected. After that, when the winch drum 1 is rotated, the limit switch 5 can reproduce its operation so as to accurately detect the upper limit position, the upper limit front position, the work fixed position, the lower limit position, etc. of the main hook 14. it can.

[0007]

According to the present invention, when the wire rope wound around the winch drum is replaced, the rotation of the detection gear can be restrained by the locking body, so that the limit switch for detecting the feed amount can be used. The operating point can be reliably held without being disturbed, and the reproducibility of the operating position can be maintained with high accuracy. In the replacement work,
The work of removing and installing the spacer installed at one end of the slide groove requires only a very small number of bolts, and the work of removing and installing the gear case is also omitted. Significant shortening is achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lock device for a limit switch / gear unit for detecting a crane lift according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a lift detecting device 20 to which the present invention is applied, which is a main winding lift detecting device for a main wire rope of a crane, in a state in which the crane is in operation. This is a pinion 2 that rotates in conjunction with a winch drum 1 that winds the wire rope 11 of the crane 30 shown in FIG. 7, a detection gear 3 that meshes with the pinion 2, and a gear that covers the pinion 2 and the detection gear 3. The case 4 and the detection shaft 3a, which extends from the detection gear 3 in parallel with the pinion shaft 2a and protrudes, are supported, and the wire rope 11 reaches a predetermined feeding amount or winding amount based on the rotation of the detection shaft 3a. The limit switch 5 is provided for detecting that the action has been taken. FIG. 2 is a perspective view showing a state in which the main hoist lift detecting device 20 is stopped when the wire rope is replaced, and FIG.
0 (see FIG. 7) shows an arrangement state of the two main hoist lift detecting devices 20A and 20B installed on the main club 12. The main hoist lift detecting devices 20A, 20B are provided on the floor surface 12a of the main club 12 which can traverse in the vicinity of the winch drums 1A, 1B for winding and unwinding the two wire ropes 11A, 11B, respectively. Is slightly higher than the winch drums 1A and 1B. Each winch drum 1 transmits power from a drum driving motor (not shown) mounted on the main club 12 through one of a plurality of output shafts provided on a speed reducer (not shown), It is designed to be rotated.

At the upper part of the main hook 14 for suspending the ladle 13 (see FIG. 7), two sheaves 15A,
15B is provided, but winch drums 1A, 1B
From the same length of wire rope 11A, 11B at the same time
Are simultaneously fed down, and are simultaneously raised by winding the same length, so that the ladle 13 can be raised and lowered without changing the left and right postures. As shown in FIG. 1, the main winding head detecting device 20 includes a gear case 4 for accommodating the detection gear 3 and the like, a switch / gear unit 7, which will be described later, a switch base 5A having a limit switch 5, and a slide groove 8.
and a switch base 8 having a formed therein. Further, as a lock device of the switch gear unit 7, a locking body 9 for preventing idling of the detection gear 3 and a spacer 10 interposed between the switch base 5A and the end of the slide groove 8a are provided. The gear case 4 of each main hoist lift detecting device 20 is bent to have a U-shaped cross section, and has a U-shape so as to surround the detection gear 3 and the pinion 2. 4a and pinion cover 4b. These covers 4a,
4b are butted to face each other, and the upper plate 4b
p and the lower plate 4q shown in FIG. The support member 4 attached to the lower portion of the gear cover 4a
By bolting r and 4r to the attachment members 8t and 8t, the entire gear case 4 is fixed to the pedestal 8s. The side surfaces of the gear case 4 are attached with cover plates 4d, 4e, 4f on the side where the switch gear unit 7 is not located, and cover the side surfaces of the detection gear 3 and the pinion 2.

As shown in FIG. 1, the inside of the gear case 4 can be disengaged from the detection gear 3 and the pinion 2 to displace the detection gear 3 in the direction away from the pinion 2. The space 6 that can be created is secured.
When the wire rope 11 is replaced, the inner surface 4c of the gear case 4 displaces the detection gear 3 from the pinion 2 in the space 6 in the direction of arrow R, and when the displacement reaches a predetermined distance S, the detection gear 3 meshes with the detection gear 3. A locking body 9 that prevents the detection gear 3 from idling is fixed by welding or the like. The locking body 9 may be anything that can engage with the teeth of the detection gear 3 and restrain the rotation of the detection gear 3, but in this example, it has the same module as the detection gear 3. Internal gears are used. Since the number of teeth is not required to be large, it is, for example, a partial gear having five tooth profiles. Therefore, when the detection gear 3 which constitutes the switch gear unit 7 is moved by a predetermined distance S together with the switch base 5A, as will be described later, the teeth of the detection gear 3 and the teeth of the locking body 9 mesh with each other. As will be described later, the movement of the detection gear 3 is restricted, and the internal mechanism of the limit switch 5 is also kept as it is. The switch / gear unit 7 is a unit in which a publicly known limit switch 5 for detecting the upper and lower limit positions and work fixed positions of the main hook 14 in normal operation, and further, the known upper and lower limit positions are integrated with the above-described detection gear 3. Is. Then, the limit switches 5 provided on the main winding head detecting devices 20A and 20B respectively have the two main winding head detecting devices 20A and 2B.
It is arranged on the opposite side of 0B (see FIG. 3).

The detection shaft 3a extending from the side of the gear case 4 of the detection gear 3 is supported by a bearing (not shown) built in the casing of the limit switch 5, and the detection shaft 3 is supported.
By connecting a to a shaft of a worm gear (not shown) in the limit switch 5, the detection gear 3 and the limit switch 5 are integrated, and the switch gear unit 7 is constructed. Therefore, when the detection gear 3 rotates, the worm gear also rotates, and when the worm wheel (not shown) that meshes with the worm gear rotates, the rotation of the cam attached to the shaft of the worm wheel causes the switch unit to rotate. The contact of is designed to be connected and disconnected. By the way, the rotation speed of the drum drive motor is set to 720
If it is rpm, the rotation reduced by 1/20 by the reduction gear is transmitted to the pinion shaft 2a. The reduction ratio between the pinion 2 and the detection gear 3 is 40/85, and the reduction ratio of the worm gear in the limit switch 5 is 1/80.
The rotation speed of the cam is 720 x 1/20 x 40/85 x 1
/80=0.21 rpm. The rotation speed of the detection gear 3, that is, the winding amount of the wire rope 11 is known by the operation of the switch portion, and the main hook 1 that has been lifted and lowered.
4, it is possible to detect the ascending limit position, the work fixed position, the upper limit front position, and the descending limit position. That is, the limit switch 5 detects the winding-up limit and the feeding-out limit of the wire ropes 11A and 11B, and further the required intermediate feeding-out position. In addition, on the front surface of the limit switch 5, an electric wiring 5c for supplying electric power and a wiring pipe for protecting the electric wiring are provided along the pedestal 8s.

Such a switch / gear unit 7
In order to displace the wire rope 11 when the wire rope 11 is replaced, as shown in FIG. 4, the limit switch 5 has two slopes 28, 28 formed on the upper surfaces of the left and right end portions, and two limit skids 5a, 5a extending in the left-right direction. Naru switch base 5
It is attached to A. That is, the limit switch 5 is attached to the switch base 5 by the three protruding portions below the limit switch 5 and the mounting bolts 22 inserted into the intermediate plate member 5b.
It is fixed to A. As shown in FIGS. 5 and 6, a switch base 8 that movably supports the switch base 5A is provided. This is longer than the switch base 5A and is provided with a slide groove 8a capable of displacing the switch base 5A by a desired distance, and is fixed to the upper surface of the pedestal 8s shown in FIG. 1 and the like. This slide groove 8a
At one end 8m and the other end 8n, skids 5a, 5
An inner slope 29 that corresponds to the outer slope 28 of a is formed, while a substantially square guide member 8g is provided at the central portion. Front and rear side surfaces 8h, 8h and skids 5a, 5a
The switch base 5A is guided by a guide member 8g when the switch base 5A is displaced in the left-right direction. This switch stand 8
A screw hole 27 for fixing the spacer 10 with a fixing bolt 27 (see FIG. 6) is provided on the left side of the guide member 8g.
a and 27a are provided. The same screw holes 27a, 27a are also formed on the right side, so that one spacer 10
It is possible to change the position in the reverse position. That is, as shown in FIG.
In the state where the detection gear 3 of 0B is meshed with the pinion 2, the switch base 5A is moved to the one end 8 of the slide groove 8a.
Therefore, the spacer 10 is interposed between the other end 8n and the switch base 5A. As shown in FIG. 2, when the detection gear 3 is engaged with the locking body 9, the switch base 5A is moved to the other end 8n of the slide groove 8a.
The spacer 10 is interposed between the one end 8m and the switch base 5A. The spacer 10 has a length equal to the above-mentioned predetermined distance S, and is always fastened by the two fixing bolts 27 to keep the switch base 5A at the predetermined position in the slide groove 8a. used.

As shown in FIG. 5, the left slanted lower surface 10a of the spacer 10 located at the other end 8n is the outer slanted surface 2 of the skids 5a, 5a constituting the switch base 5A.
8 and 28, which are formed so as to abut on the right and upper inclined surfaces 1
0b is formed so as to match the inner slope 29 of the slide groove 8a of the switch base 8. This spacer 1
If 0 is rotated 180 degrees and the left and right are reversed, as shown in FIG. 6, it can be inserted also in one end 8m. The predetermined distance S at which the detection gear 3 is displaced
Since it suffices that there is approximately 25 mm, the width of the spacer 10 is also 25 mm. By the way, as shown in FIG.
Below the main club 12, there is an auxiliary club 24 that can traverse freely.
Is provided and the wire rope 25 fed from a winch drum connected to a motor or speed reducer (not shown),
An auxiliary hook 26 that can be raised and lowered is attached. And
For example, the ladle 1 hung on the main hooks 14 and 14.
When 3 is stopped at the working position, the auxiliary club 24 is traversed, the auxiliary wire rope 25 is paid out, the auxiliary hook 26 is lowered, the vicinity of the bottom of the ladle 13 is lifted and tilted, and the hot metal is discharged from the outlet 13a. It is designed to be poured into the converter.

The main hoist lift detecting devices 20A and 20B equipped with the lock device according to the present invention having the above-described structure, switch base 5 when replacing the wire ropes 11A and 11B wound around the winch drums 1A and 1B.
Through the movement of A, the detection gear 3 integrated with the limit switch 5 is separated from the pinion 2 and engaged with the locking body 9 to prevent the detection gear 3 from idling, and thus the worm wheel inside the limit switch 5 is prevented. It is possible to prevent the unnecessary rotation of the. The blast furnace is regularly repaired at fixed intervals, and the wire ropes 11A and 11B of the crane 30 are replaced by taking advantage of such opportunities. As a preparatory work, the main hook 14 is stopped at a predetermined height position of, for example, 1 m from the floor surface of the steelmaking factory.
At this time, the pinion 2 and the detection gear 3 of the main winding head detecting device 20 are in mesh with each other as shown in FIG. In this state, the spacer 10 provided in the slide groove 8a of the switch base 8 provided in the main winding head detecting device 20 is removed. That is, a total of four fixing bolts 27, 27 that fix the spacer 10 to the switch base 8 are removed, and the inner slope 29
The spacer 10 with which the inclined upper surface 10b is brought into contact (see FIG. 5) is pulled out in the arrow M direction. Then, the limit switch 5 fixed to the switch base 5A via the mounting bolts 22 and the detection gear 3 are connected to each other by a locking body 9 that separates the space 6 from each other.
Displace in the direction of. At this time, skids 5a, 5a
Is guided by sliding the inner surface thereof on the front and rear side surfaces 8h, 8h of a guide member 8g (see FIG. 5) formed on the bottom surface of the switch base 8. When the amount of movement reaches a predetermined distance S, the pinion 2
The detection gear 3 separated from the inner surface 4 of the gear case 4
The teeth of the locking body 9 of c are engaged (see FIG. 2). If the pulled out spacer 10 is rotated 180 degrees to be in the reverse posture and is inserted from the direction of the arrow N into the gap formed between the one end 8m of the slide groove 8a and the switch base 5A as shown in FIG. The gear 3 does not come off from the locking body 9. As a result, even if the pinion 2 is rotated by some force, the rotation is not transmitted to the detection gear 3 and the state of the switch portion in the limit switch 5 is maintained by the detection gear 3 being restrained. .

Next, the old wire ropes 11A and 11B
DOWN to cut the tip and connect a new wire rope to the cut point. The winch drums 1A and 1B are rotated to pull up the old wire ropes 11A and 11B, disconnect the connection portion, and deposit the new wire rope on the club 12. Old wire rope 11A, 1
1B rotates the winch drums 1A and 1B in the reverse direction and is lowered to the ground. The new wire ropes 11A and 11B are stopped at the ends of the winch drums 1A and 1B, and the winch drums 1A and 1B are normally rotated again and wound. New wire ropes 11A and 11B on winch drums 1A and 1B
The winch drums 1A and 1B so that the main hook 14 is at a predetermined height position 1 m above the floor.
Adjust the payout amount or winding amount of the wire ropes 11A and 11B with. As shown in FIG. 2, the fixing bolt 27 for fixing the spacer 10 interposed at the one end 8m of the slide groove 8a is removed, and the spacer 10 is pulled out in the arrow M direction. When the switch / gear unit 7 and the switch base 5A are moved to their original positions, the detection gear 3 is meshed with the pinion 2, and the switch portion of the limit switch 5 has a main hook in relation to the feeding amount of the wire rope 11. The previous state in which the predetermined height position of 14 is detected is reproduced. The skids 5a, 5a that constitute the switch base 5A by interposing the spacer 10 in the original posture between the other side 8n of the slide groove 8a and the switch base 5A.
When the fixing bolt 27 is tightened in a state where the inclined lower surface 10a is aligned with the outer inclined surfaces 28, 28, it is fixed to the switch base 8 and the meshing between the detection gear 3 and the pinion 2 is reproduced. That is, in each limit switch 5, the upper limit position, the upper limit front position, the work fixed position and the lower limit position of the main hook 14 can be accurately detected as before. In such work, the bolt removing work and the mounting work can be realized by a minimum operation, that is, a total of four bolt operations. Therefore, it is possible to avoid the troublesome replacement work of removing the upper cover and shifting the limit switch and the detection gear together with the lower cover as in the conventional case, and it is possible to greatly reduce the working time. Further, the readjustment operation of the limit switch, which is necessary in the conventional wire rope replacement work, is not required. In the above description, the apparatus for detecting the main hoist of a club-type overhead crane in a steelmaking factory has been taken as an example, but the present invention is a wire rope replacement work for a crane installed in a continuous casting factory, etc. Needless to say, it can also be applied to general cranes and their auxiliary wire ropes.

[Brief description of drawings]

FIG. 1 is a perspective view of a main winding head detecting device to which the present invention is applied, in a normal operating state.

FIG. 2 is a perspective view of a state in which a detection gear in the main hoist lift detecting device when the wire rope is replaced is meshed with a locking body.

FIG. 3 is a perspective view illustrating an arrangement state of a main winding head detecting device including two groups on a main club.

FIG. 4 is a perspective view of a switch base and a limit switch.

FIG. 5 is a perspective view of a switch base and a spacer.

FIG. 6 is a perspective view of the switch base when the spacer is replaced.

FIG. 7 is a perspective view of an example of a crane to which the present invention is applied.

FIG. 8 is a perspective view of a conventional main winding head detecting device.

[Explanation of symbols]

1 ... Winch drum, 2 ... Pinion, 2a ... Pinion shaft, 3 ... Detection gear, 3a ... Detection shaft, 4 ... Gear case, 4c ... Inner surface, 5 ... Limit switch, 5A ... Switch base, 6 ... Space, 7 ... Switch・ Gear unit,
8 ... switch base, 8a ... slide groove, 8m ... one end, 8
n ... other end, 9 ... locking body, 10 ... spacer, 11, 11
A, 11B ... Wire rope, 20, 20A, 20B ...
Main hoist detection device, 30 ... Crane (club type overhead crane), S ... Predetermined distance.

Claims (1)

[Scope of utility model registration request] 1. A pinion that rotates in conjunction with a winch drum for winding a wire rope of a crane, a detection gear that meshes with the pinion, a gear case that covers the pinion and the detection gear, and a pinion shaft from the detection gear. And a limit switch that supports a detection shaft that extends in parallel with and protrudes, and that detects, based on the rotation of the detection shaft, that the wire rope has reached a predetermined feeding amount or winding amount, In the gear case, a space is secured in which the detection gear and the pinion can be disengaged from each other and the detection gear can be displaced in a direction away from the pinion. In order to displace the switch / gear unit that is integrated with the A switch base that supports the gear case is provided.On the inner surface of the gear case, a locking body that displaces from the pinion in the space and meshes with the detection gear when a predetermined distance is reached, and prevents idling of the detection gear, is provided. The switch base is provided with a slide groove longer than the switch base and capable of displacing the switch base. The slide groove is provided at a predetermined distance between the switch base and an end of the slide groove. A spacer having an equal length is interposed so that the spacer can be replaceably fixed between the switch base and one end of the slide groove and between the switch base and the other end of the slide groove. Locking device for limit switch and gear unit for crane lift detection.