JPH05105400A - Small-sized hauling hoist - Google Patents

Abstract

PURPOSE:To make it possible that a switching lever surely maintains a braking state in a neutral state, and perform switching operation to the braking state or to a racing state swiftly. CONSTITUTION:A disc nut 13 is threadedly engaged with a pinion shaft 1, a racing handle 25 is mounted to one end of the pinion shaft 1, and a spring rest member 27 is contained inside the disc nut 13 freely rotatably. The spring rest member 27 is mounted to the pinion shaft 1 and interposed between the racing handle 25 and the disc nut 13. A torsion spring 30 that explosively energizes the disc nut 13 so that it rotates in the operating direction of a braking mechanism 20 is interposed between the disc nut 13 and the spring rest member 27. And, balls 37 that freely engage with disengage from the notch 38 of the disc nut 13 and explosively energized by a spring 36 are provided in the spring rest member 27.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a small tow hoist.

[0002]

2. Description of the Related Art Conventionally, as a traction hoisting machine of this type, there has been a free-running device in a lever type small hoisting and traction device described in Japanese Patent Publication No. 63-3838.

[0003]

In the above-mentioned traction device,
To switch the brake from idling (idling) to the braking state and wind up the chain, consciously operate the idling handle while applying a load to the chain to bring the brake mechanism into the braking state. Moreover, the chain has to be wound with the switching lever in the wound state (normal rotation position), and smooth and quick work cannot be performed.

Further, when a sudden load is applied to the chain in the idling state, the chain is temporarily braked. However, when the load is removed, the chain returns to the idling state again, and there is a problem that the chain falls when the load is light. ..

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a pinion shaft screwed with a disc nut by screwing so as to be able to move forward and backward, and an idling handle is integrally rotated at one end of the pinion shaft. A spring receiving member is rotatably internally provided in the hole portion of the disc nut, and the spring receiving member is integrally rotatably attached to the pinion shaft so as to be interposed between the idling handle and the disc nut. Further, a torsion spring that elastically urges the disc nut to rotate in the operating direction of the brake mechanism via the screw connection is interposed between the disc nut and the spring receiving member. On the nut,
Attach a feed handle that rotates the disc nut,
Further, an engaging notch is formed in the hole of the disc nut, and the spring receiving member is provided with a locking ball which is elastically urged by the spring and can be engaged with and disengaged from the engaging notch. is there.

[0006]

In the normal state, the rotational torque of the torsion spring exerts a force in the operating direction of the brake mechanism on the disc nut to forcibly tighten the brake. Therefore, even if a light load is applied to the load chain, the braking state can be reliably maintained.

Further, if the load chain is loaded from the idling state in which the brake is loosened to the winding (normal rotation) state and the operating lever is swung, the braking state is automatically restored and the hoisting work is immediately started. It can be carried out.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiments.

In FIG. 1, 1 is a pinion shaft to which a pinion 2 is fixed at one end, 3 is a load sheave, which is rotatably fitted onto the shaft 1, and the load sheave 3 has load metals 4 and 4 interposed therebetween. And is pivotally attached to the side plates 5 and 5.

Reference numeral 6 is a load gear fixed to the load sheave 3, and is always connected to the pinion 2 via a reduction gear group 7.

Reference numeral 8 denotes a gear box, which is a reduction gear group 7
Etc. are surrounded and fixed to one side plate 5. 9
Is a ratchet cover, which is fixed to the other side plate 5.

Numeral 10 is an upper hook, which is a side plate 5,
5 is attached so as to be rotatable and swingable.

A load chain 11 is suspended from the load sheave 3 and hangs down. A load hook is attached to the lower end of the drawing to apply a load.

A disk hub 12 is fixed to the shaft 1 and comprises a small cylindrical portion 12a and an outer flange portion 12b.

Reference numeral 13 denotes a disc nut, and a screw portion 15 (which is a right-hand screw) of the shaft 1 is screwed into a screw hole 15 of the disc nut 13 so that the screw nut 15 can be moved forward and backward.

A ratchet wheel 16 and brake linings 17, 17 are provided between the disc hub 12 and the disc nut 13.
However, it is inserted freely.

In the illustrated example, the small cylindrical portion 12a of the disk hub 12 is shown.
The interlocking ring 18 is rotatably fitted to the ratchet wheel 16 in which serrations, splines, etc. are formed on the outer peripheral surface of the interlocking ring 18 and corresponding serrations, splines, etc. are formed on the inner surface of the through hole. Also, the brake linings 17, 17 are fitted to each other so that the contact surfaces of the ratchet wheel 16 and the brake lining 17 do not rotate relative to each other.

Braking claw pieces 19, 19 are provided on the side plate 5 and engage with the teeth of the ratchet wheel 16 on the outer periphery.

The above-mentioned disc hub 12 and disc nut 1
3, the interlocking ring 18, the ratchet wheel 16, the brake linings 17, 17 and the braking pawls 19 and the like constitute a brake mechanism 20.

Reference numeral 21 designates a lever for manual operation, which is mounted swingably around the axis L of the shaft 1.

The lever 21 has a switching piece 23 having a forward / reverse rotation claw piece which engages / disengages with the switching gear portion 22 of the disc nut 13, and is built in the base end portion thereof. twenty four
You can switch between forward, reverse, and neutral by operating.

Reference numeral 25 is an idling handle which is attached to one end of the shaft 1 through the serrations 26 and the like (together with the shaft 1) so as to rotate integrally.

Reference numeral 27 is a spring bearing member which is integrally (rotatably) attached to the shaft 1 through the serrations 28 and the like, and is interposed between the idling handle 25 and the disc nut 13.

The spring receiving member 27 is a disc nut.
It is rotatably internally contained in a circular hole portion 29 that is connected to the screw hole 15 of 13.

As shown in FIGS. 1 and 2, a disc nut
Spring receiving member facing the hole 29 of 13 with a slight gap
A radial through hole 35 is formed in the large diameter portion 34 of the 27, and a pair of springs 36, 36 and locking balls 37, 37 are formed in the through hole 35.
Will be installed internally.

The locking balls 37, 37 are formed by the spring 3
Disk nut 1 is elastically urged outward by 6, 36
A pair of semi-circular engaging notches 38, 38 formed in the axial direction and facing the hole 29 of the third hole are engageable and disengageable (as shown in FIGS. 2 and 4).

Reference numeral 30 denotes a torsion spring which is externally fitted to the small diameter portion 33 of the spring receiving member 27. One end of the spring 30 is inserted into a small hole 31 (in the axial direction) of the disc nut 13, The other end is inserted into a small groove (in the axial direction) 32 of the spring receiving member 27.

In this way, the spring 30 is interposed between the disc nut 13 and the spring receiving member 27, and by this spring 30, the disc nut 13 is connected to the brake mechanism 20 via the screw connection between the shaft 1 and the disc nut 13. It is elastically urged to rotate in the operating direction.

That is, the spring 30 constantly and elastically applies the rotational torque so that the disc nut 13 advances in the direction of the arrow T (shown in FIG. 1).

Reference numeral 39 denotes a feed handle, which is attached to the groove 40 of the disc nut 13 by engaging the convex teeth 41 of the feed handle 39. With this feed handle 39, the disc nut
13 can be rotated.

1 and 2 show the braking state of the brake mechanism 20. In this state, the torsional elastic force of the spring 30 causes the disc nut 13 to receive a force to rotate around the screw portion 14. The disc nut 13 is elastically urged and moves in the direction (arrow T direction) in which the brake lining 17 is pressed.

Therefore, in the state shown in FIGS. 1 and 2, the disc nut 13 presses the brake linings 17, 17 and the ratchet wheel 16 to maintain the braking state.

In the braking state of the brake mechanism 20, the balls 37, 37 of the spring receiving member 27 are orthogonal to the notches 38, 38 of the disc nut 13.

3 and 4 show the idling state in which the brake mechanism 20 is not braked. To make this state, the switching piece 23 is set in a reverse rotation (winding down) state, and from the state shown in FIGS. 1 and 2, the idle handle 25 is gripped with a hand and rotated about 90 ° to the right as indicated by an arrow R.

Then, together with the rotation of the idling handle 25,
The shaft 1, the spring receiving member 27, and the balls 37, 37 (as the spring receiving member 27 rotates) rotate about 90 ° in the direction of arrow R.

Then, as shown in FIGS. 3 and 4, each ball 37,
37 is elastically urged and locked by the notches 38, 38 by the springs 36, 36, and the disc nut 13 is moved in the direction of arrow E by the rotation of the shaft 1 and is separated from the brake lining 17 to a non-contact position. Braking slips.

In this idling state, if the switching piece 23 (see FIG. 1) is set to the neutral state, the load sheave 3 (see FIG. 1).
Rotates freely, so load chain 11 (see Fig. 1)
Can be run freely.

At this time, if a sudden load (exceeding the locking force between the spring receiving member 27 and the disc nut 13 determined by the ball 37, the notch 38, the spring 30, etc.) is applied to the load chain 11, the balls 37, 37 Is out of the notches 38, 38,
With rotation of the shaft 1 in the direction of arrow M, the disc nut 13 instantaneously moves in the direction opposite to the direction E, and the idling state is automatically restored to the braking state shown in FIGS. 1 and 2.

Even when the load applied to the load chain 11 is removed, the spring 30 causes the disc nut 13 to be forcibly pressed by the brake lining 17 as described above, so that the braking state is maintained without returning to the idling state again. The load chain 11 can be hoisted and unwound by manually rotating the feed handle 39 in this state.

In the idling state (FIGS. 3 and 4), unless the load is suddenly applied to the load chain 11 as described above, the balls 37, 37 are locked in the notches 38, 38. Since the shaft 1 is maintained, the shaft 1 does not rotate integrally with the disc nut 13 and does not return to the braking state without permission.

In order to change from the idling state to the braking state, the switching piece 23 is normally rotated (raised), a proper load is applied to the load chain 11, and the lever 21 is swung. Often, the balls 37, 37 are disengaged from the notches 38, 38, and the braking state shown in FIGS.

Therefore, unlike the conventional one, it is not necessary to consciously operate the idling handle 25 to restore the braking state, and the hoisting operation can be performed easily and quickly.
It does not take time and effort.

Next, FIGS. 5 and 6 show another embodiment in which an overload preventing mechanism 42 is additionally provided, and shows a case where a one-way clutch hub is used as the disc nut 13.

The overload preventing mechanism 42 is composed of a clutch hub (disc nut) 13, a slip gear 47, rollers 49 ..., A fixed disc 51, a disc spring 52, a nut member 53 and the like.

The clutch hub (disc nut) 13 includes an outer collar portion 43 in contact with the brake lining 17, an outer peripheral groove 44 in sliding contact with a roller 49, a serration 45, and a male screw portion 46.
It has on the outer peripheral surface.

Clutch linings 48, 48 are baked and stretched on both end surfaces of the slip gear 47, and a plurality of cam grooves 50 for holding a roller 49 movably in the circumferential direction are provided on the inner peripheral surface of the slip gear 47. (Three locations in the illustrated example) are formed.

Then, the clutch hub (disc nut)
One clutch lining 48 of the slip gear 47 is brought into contact with the outer flange portion 43 of 13 and the roller 49 is connected to the cam groove 50 and the outer peripheral groove 44.
And the slip gear 47 is fitted onto the clutch hub (disc nut) 13.

At this time, the gap between the cam groove 50 and the outer peripheral groove 44
One of the 54 is narrower than the outer diameter of the roller 49, and the other is wider.

Switching gear portion on the outer peripheral side of the slip gear 47
The forward rotation claw piece and the reverse rotation claw piece of the switching piece 23 at the base of the lever 21 are selectively engaged with the lever 22.

Further, the fixed disc 51 comes into contact with the other clutch lining 48 of the slip gear 47, and the fixed disc 51 is axially movable via the serrations 45 of the clutch hub (disc nut) 13. Mounted.

Then, through the disc spring 52, the nut member 53
Elastically presses the fixed disk 51 against the slip gear 47.

By adjusting the position of the nut member 53 to be screwed onto the male screw portion 46, the slip gear 47 can adjust the overload set value for idling with respect to the clutch hub (disc nut) 13.

The feed handle 39 is (similar to FIG. 2).
The concave groove 40 and the convex tooth 41 are engaged with each other and attached to the nut member 53.

However, when the load chain 11 is wound up, the one-way clutch composed of the roller 49, the cam groove 50, etc., moves the roller 49 to the wide side of the gap 54 (as shown in FIG. 6). In the loosely inserted state, the rotational force given by the operation of the lever 21 is applied to the clutch hub (disc nut) 13 from the outer collar portion 43 and the fixed disc 51 through the clutch linings 48, 48 of the slip gear 47. Transmitted.

During winding, the roller 49 moves to the narrow side of the gap 54, forming a wedge between the cam groove 50 and the outer peripheral groove 44, and the clutch hub (disc nut) 13 The slip gear 47 is coupled and the rotational force given by the operation of the lever 21 is transmitted to the clutch hub (disc nut) 13 via the roller 49.

Also in the tow hoist equipped with the overload preventing mechanism 42 of the illustrated example, the arrow R is the same as in the previous embodiment (of FIG. 1).
When rotated about 90 ° in the direction, as shown in Figs. 7 and 8, the arrow E
The clutch hub (disc nut) 13 moves in the direction and becomes idling.

On the contrary, in order to set the braking state, the load chain
Apply moderate load to 11 and rotate switching piece 23 forward (winding)
As for the state, it is sufficient to swing the lever 21, and the braking state shown in FIGS. 5 and 6 is immediately established.

According to the present invention, the overload prevention mechanism 42
Other than the parts such as the clutch hub (disc nut) 13 that compose the above, there is an advantage that the parts of the embodiment of FIG. 5 and the embodiment of FIG. 1 can be shared.

[0059]

The present invention has the following great effects.

Once the braking state is reached, the force due to the rotational torque of the torsion spring 30 that advances in the operating direction of the brake mechanism 20 always acts on the disc nut 13 and does not return to the idling state without permission. The braking state can be reliably maintained even under load. That is, it is possible to prevent the load chain 11 from falling due to a light load.

The operation can be easily and quickly switched between the braking state and the idling state. Especially, when the idling state is switched to the braking state to wind up the chain, the idling handle 25 is consciously operated for braking as compared with the conventional one. Since it is possible to save the trouble of restoring the state, it is possible to further improve the work efficiency.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1 showing a braking state.

FIG. 3 is an explanatory view of a main part in a idling state.

FIG. 4 is a sectional view taken along line AA of FIG.

FIG. 5 is a sectional front view showing another embodiment.

6 is a sectional view taken along the line BB of FIG. 5 showing a braking state.

FIG. 7 is an explanatory view of a main part in a idling state.

8 is a sectional view taken along line BB of FIG.

[Explanation of symbols] 1 Pinion shaft 13 Disc nut 20 Brake mechanism 25 Idling handle 27 Spring receiving member 29 Hole 30 Torsion spring 36 Spring 37 Ball 38 Notch 39 Feed handle

[Procedure amendment]

[Submission date] November 7, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

[Title of Invention] Small tow hoist

[Claims]

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a small tow hoist.

[0002]

2. Description of the Related Art Hitherto, as a traction hoisting machine of this type, there has been a free-running device in a lever type small hoisting and traction device described in Japanese Patent Publication No. 63-3838.

[0003]

In the above-mentioned traction device,
To switch the brake from idling (idling) to the braking state and wind up the chain, consciously operate the idling handle while applying a load to the chain to bring the brake mechanism into the braking state. Moreover, the chain has to be wound with the switching lever in the wound state (normal rotation position), and smooth and quick work cannot be performed.

Further, when a sudden load is applied to the chain in the idling state, the chain is temporarily braked. However, when the load is removed, the chain returns to the idling state again, and there is a problem that the chain falls when the load is light. ..

By the way, the check described in the above Japanese Patent Publication No. 63-3838.
In addition to the pulling device, the load chain is conventionally overloaded.
Then, the slip gear that transmits the torque of the lever
A small checker with an overload prevention mechanism that idles against the hub.
The hoisting machine had the following problems.

This overload prevention mechanism is provided with an elastic member.
Press the slip gear against the clutch hub with the nut member.
Structure to rotate the slip gear and the clutch hub as a unit
Met. The slip gear slips due to overload.
Limit value of pressing friction force (operation setting of overload prevention mechanism
Value), and change the screwing position of the nut member to the clutch hub.
I was adjusting it.

However, the nut member is surrounded by the idling handle.
The above hoisting machine as a whole cannot be rotated from the outside.
When finely adjusting the deviation of the operation set value after assembly (for example,
For example, at the time of final inspection before product shipment or after regular use after a certain period of time.
(During inspection), disassemble the idling handle and operate the nut member.
After making it into a functional state, screw the nut member back and forth
It was troublesome to adjust and reassemble the whole.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a pinion shaft screwed with a disc nut by screwing so as to be able to move forward and backward, and an idling handle is integrally rotated at one end of the pinion shaft. A spring receiving member is rotatably internally provided in the hole portion of the disc nut, and the spring receiving member is integrally rotatably attached to the pinion shaft so as to be interposed between the idling handle and the disc nut. Further, a torsion spring that elastically urges the disc nut to rotate in the operating direction of the brake mechanism via the screw connection is interposed between the disc nut and the spring receiving member. On the nut,
Attach a feed handle that rotates the disc nut,
Further, an engaging notch is formed in the hole of the disc nut, and the spring receiving member is provided with a locking ball which is elastically urged by the spring and can be engaged with and disengaged from the engaging notch. is there.

[0009] Further , a small tow provided with an overload prevention mechanism.
It is a hoist, and the operation set value of the overload prevention mechanism is screwed on.
Enclose the nut member to be adjusted in position from the outside
The feed handle provided on the
Which are engaged or locked with each other so that they can rotate
It

[0010]

In the normal state, the rotational torque of the torsion spring exerts a force in the operating direction of the brake mechanism on the disc nut to forcibly tighten the brake. Therefore, even if a light load is applied to the load chain, the braking state can be reliably maintained.

Further, if the load chain is loaded from the idling state in which the brake is loosened to the winding state (normal rotation) and the operating lever is swung, the braking state is automatically restored and the winding operation is immediately started. It can be carried out.

In a small tow hoist with an overload prevention mechanism
If you rotate the feed handle in the fully assembled state,
Rotational torque can be transmitted to the operation member and the overload prevention mechanism operates.
Fine adjustment of the set value is possible.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiments.

In FIG. 1, 1 is a pinion shaft to which a pinion 2 is fixed at one end, 3 is a load sheave which is rotatably fitted onto the shaft 1, and the load sheave 3 has load metals 4 and 4 interposed therebetween. And is pivotally attached to the side plates 5 and 5.

Reference numeral 6 is a load gear fixed to the load sheave 3, and is always connected to the pinion 2 through a reduction gear group 7.

Reference numeral 8 denotes a gear box, which is a reduction gear group 7
Etc. are surrounded and fixed to one side plate 5. 9
Is a ratchet cover, which is fixed to the other side plate 5.

Reference numeral 10 denotes an upper hook, which is a side plate 5,
5 is attached so as to be rotatable and swingable.

Reference numeral 11 denotes a load chain suspended from the load sheave 3 and hung. A load hook is attached to the lower end of the figure to apply a load.

A disc hub 12 is fixed to the shaft 1 and comprises a small cylindrical portion 12a and an outer collar portion 12b.

Reference numeral 13 denotes a disc nut, and a screw portion 15 (right screw) of the shaft 1 is screwed into a screw hole 15 of the disc nut 13 so that the screw nut 15 can be moved forward and backward.

A ratchet wheel 16 and brake linings 17, 17 are provided between the disc hub 12 and the disc nut 13.
However, it is inserted freely.

In the illustrated example, the small cylindrical portion 12a of the disk hub 12 is shown.
The interlocking ring 18 is rotatably fitted to the ratchet wheel 16 in which serrations, splines, etc. are formed on the outer peripheral surface of the interlocking ring 18 and corresponding serrations, splines, etc. are formed on the inner surface of the through hole. Also, the brake linings 17, 17 are fitted to each other so that the contact surfaces of the ratchet wheel 16 and the brake lining 17 do not rotate relative to each other.

Braking claw pieces 19, 19 are provided on the side plate 5 and engage with the teeth of the ratchet wheel 16 on the outer periphery.

Disc hub 12 and disc nut 1 described above
3, the interlocking ring 18, the ratchet wheel 16, the brake linings 17, 17 and the braking pawls 19 and the like constitute a brake mechanism 20.

Reference numeral 21 denotes a lever for manual operation, which is mounted around the shaft center L of the shaft 1 so as to be swingable.

The lever 21 has a switching piece 23, which has a forward / reverse rotation claw piece that engages / disengages with the switching gear portion 22 of the disc nut 13, built in at the base end portion thereof. twenty four
You can switch between forward, reverse, and neutral by operating.

Reference numeral 25 denotes an idling handle which is attached to one end of the shaft 1 via the serrations 26 and the like (together with the shaft 1) so as to rotate integrally.

Reference numeral 27 denotes a spring receiving member which is integrally and rotationally attached to the shaft 1 (with the shaft 1) through serrations 28 and the like, and is interposed between the idling handle 25 and the disc nut 13.

The spring receiving member 27 is a disc nut.
It is rotatably internally contained in a circular hole portion 29 that is connected to the screw hole 15 of 13.

As shown in FIGS. 1 and 2, the disc nut
Spring receiving member facing the hole 29 of 13 with a slight gap
A radial through hole 35 is formed in the large diameter portion 34 of the 27, and a pair of springs 36, 36 and locking balls 37, 37 are formed in the through hole 35.
Will be installed internally.

The locking balls 37, 37 are formed by the spring 3
Disk nut 1 is elastically urged outward by 6, 36
A pair of semi-circular engaging notches 38, 38 formed in the axial direction and facing the hole 29 of the third hole are engageable and disengageable (as shown in FIGS. 2 and 4).

Reference numeral 30 is a torsion spring externally fitted to the small diameter portion 33 of the spring receiving member 27. One end of the spring 30 is inserted into a small hole 31 (in the axial direction) of the disc nut 13, The other end is inserted into a small groove (in the axial direction) 32 of the spring receiving member 27.

In this way, the spring 30 is interposed between the disc nut 13 and the spring receiving member 27, and by this spring 30, the disc nut 13 is connected to the brake mechanism 20 through the screw connection between the shaft 1 and the disc nut 13. It is elastically urged to rotate in the operating direction.

That is, the spring 30 constantly and elastically applies the rotational torque so that the disc nut 13 advances in the direction of the arrow T (shown in FIG. 1).

[0035] 39 is a feed wheel, the grooves 40 ... of the disc nut 13, is attached to the convex tooth 41 ... it is meshed feed wheel 39. With this feed handle 39, the disc nut 13 can be rotated.

1 and 2 show the braking state of the brake mechanism 20. In this state, the torsional elastic force of the spring 30 causes the disc nut 13 to receive a force to rotate around the screw portion 14. The disc nut 13 is elastically urged and moves in the direction (arrow T direction) in which the brake lining 17 is pressed.

Therefore, in the state shown in FIGS. 1 and 2, the disc nut 13 presses the brake linings 17, 17 and the ratchet wheel 16 to maintain the braking state.

When the brake mechanism 20 is in the braking state, the balls 37, 37 of the spring receiving member 27 are orthogonal to the notches 38, 38 of the disc nut 13.

3 and 4 show the idling state in which the brake mechanism 20 is not braked. To make this state, the switching piece 23 is set in a reverse rotation (winding down) state, and from the state shown in FIGS. 1 and 2, the idle handle 25 is gripped with a hand and rotated about 90 ° to the right as indicated by an arrow R.

Then, as the idle handle 25 rotates,
The shaft 1, the spring receiving member 27, and the balls 37, 37 (as the spring receiving member 27 rotates) rotate about 90 ° in the direction of arrow R.

Then, as shown in FIGS. 3 and 4, each ball 37,
37 is elastically urged and locked by the notches 38, 38 by the springs 36, 36, and the disc nut 13 is moved in the direction of arrow E by the rotation of the shaft 1 and is separated from the brake lining 17 to a non-contact position. Braking slips.

In this idling state, if the switching piece 23 (see FIG. 1) is set to the neutral state, the load sheave 3 (see FIG. 1).
Rotates freely, so load chain 11 (see Fig. 1)
Can be run freely.

At this time, if a sudden load (exceeding the locking force between the spring receiving member 27 and the disc nut 13 determined by the balls 37, the notches 38, the springs 30 and the like) is applied to the load chain 11, the balls 37, 37 Is out of the notches 38, 38,
With rotation of the shaft 1 in the direction of arrow M, the disc nut 13 instantaneously moves in the direction opposite to the direction E, and the idling state is automatically restored to the braking state shown in FIGS. 1 and 2.

Even when the load applied to the load chain 11 is removed, the spring 30 causes the disc nut 13 to be forcibly pressed against the brake lining 17 as described above, so that the brake state is not returned to the idling state again. The load chain 11 can be hoisted and unwound by manually rotating the feed handle 39 in this state.

In the idling state (FIGS. 3 and 4), unless the load is suddenly applied to the load chain 11 as described above, the balls 37, 37 are locked in the notches 38, 38. Since the shaft 1 is maintained, the shaft 1 does not rotate integrally with the disc nut 13 and does not return to the braking state without permission.

In order to change from the idling state to the braking state, the switching piece 23 is normally rotated (raised), an appropriate load is applied to the load chain 11, and the lever 21 is swung. Often, the balls 37, 37 are disengaged from the notches 38, 38, and the braking state shown in FIGS. 1 and 2 is immediately established.

Therefore, unlike the conventional one, it is not necessary to consciously operate the idling handle 25 to restore the braking state, and the winding operation can be performed easily and quickly,
It does not take time and effort.

Next, FIGS. 5 and 6 show another embodiment in which an overload preventing mechanism 42 is additionally provided, in which a one-way clutch hub is used as the disc nut 13.

The overload preventing mechanism 42 comprises a clutch hub (disc nut) 13, a slip gear 47, rollers 49, ..., A fixed disc 51, a disc spring 52, a nut member 53 and the like.

The clutch hub (disc nut) 13 includes an outer collar portion 43 in contact with the brake lining 17, an outer peripheral groove 44 in sliding contact with the roller 49, a serration 45, and a male screw portion 46.
It has on the outer peripheral surface.

Clutch linings 48, 48 are baked and stretched on both end surfaces of the slip gear 47, and a plurality of cam grooves 50 for holding a roller 49 movably in the circumferential direction are provided on the inner peripheral surface of the slip gear 47. (Three locations in the illustrated example) are formed.

Then, the clutch hub (disc nut)
One clutch lining 48 of the slip gear 47 is brought into contact with the outer flange portion 43 of 13 and the roller 49 is connected to the cam groove 50 and the outer peripheral groove 44.
And the slip gear 47 is fitted onto the clutch hub (disc nut) 13.

At this time, the gap between the cam groove 50 and the outer peripheral groove 44
One of the 54 is narrower than the outer diameter of the roller 49, and the other is wider.

Switching gear portion on the outer peripheral side of the slip gear 47
The forward rotation claw piece and the reverse rotation claw piece of the switching piece 23 at the base of the lever 21 are selectively engaged with the lever 22.

Further, a fixed disc 51 comes into contact with the other clutch lining 48 of the slip gear 47, and the fixed disc 51 is movable in the axial direction via the serration 45 of the clutch hub (disc nut) 13. Mounted.

Then, through the disc spring 52, the nut member 53
Elastically presses the fixed disk 51 against the slip gear 47 ,
Slip gear 47 and clutch hub (disc nut) 13
Is rotated by frictional force through the clutch lining 48 etc.
It is possible to transfer.

[ Loading chain 11 winding up by lever 21 operation ]
If the load chain 11 is overloaded during
The lip gear 47 faces the clutch hub (disc nut) 13.
And slip.

By adjusting the screwing position of the nut member 53 to the male screw part 46, the strength of the elastic pressing force of the disc spring 52 can be adjusted ,
That is, the limit value (immediate value ) of the pressing frictional force at which the slip gear 47 slips with respect to the clutch hub (disc nut) 13.
The operation set value of the overload prevention mechanism 42) can be adjusted.

The feed handle 39 is provided with the nut member 53 on the outside.
It is provided so as to surround the feed handle 39 and the nut part.
The members 53 are engaged or locked with each other so that they can rotate together.
I have it.

Specifically, the feed handle 39 is attached to the nut member 53 by engaging the concave grooves 40 ... With the convex teeth 41 ... (Similar to FIG. 2). The feed handle 39 and nut
The structure for engaging and locking the member 53 has various design variations.
You are free.

Therefore, according to the embodiment of FIG. 5 and FIG.
For example, with all parts of the small towing hoist assembled,
Handle 39 (not shown, for example, feed handle 39
(With a jig with a handle that has a boss that fits on the outside)
Nut member with a snap ring etc.
The rotational torque is transmitted to 53 to activate the overload prevention mechanism 42.
The fixed value can be finely adjusted.

However, when the load chain 11 is wound up, the one-way clutch composed of the roller 49, the cam groove 50 and the like moves the roller 49 to the wide side of the gap 54 (as shown in FIG. 6). In the loosely inserted state, the rotational force given by the operation of the lever 21 is applied to the clutch hub (disc nut) 13 from the outer collar portion 43 and the fixed disc 51 through the clutch linings 48, 48 of the slip gear 47. Transmitted.

When the roller 49 is unwound, the roller 49 moves to the narrow side of the gap 54, forming a wedge between the cam groove 50 and the outer peripheral groove 44, and the clutch hub (disc nut) 13 The slip gear 47 is coupled and the rotational force given by the operation of the lever 21 is transmitted to the clutch hub (disc nut) 13 via the roller 49.

In the tow hoisting machine with the overload preventing mechanism 42 shown in the figure, the arrow R is shown as in the previous embodiment (of FIG. 1).
When rotated about 90 ° in the direction, as shown in Figs. 7 and 8, the arrow E
The clutch hub (disc nut) 13 moves in the direction and becomes idling.

On the contrary, in order to set the braking state, the load chain
Apply moderate load to 11 and rotate switching piece 23 forward (winding)
As for the state, it is sufficient to swing the lever 21, and the braking state shown in FIGS. 5 and 6 is immediately established.

According to the present invention, the overload prevention mechanism 42
Other than the parts such as the clutch hub (disc nut) 13 that compose the above, there is an advantage that the parts of the embodiment of FIG. 5 and the embodiment of FIG. 1 can be shared.

[0067]

The present invention has the following great effects.

In the small tow hoisting machine according to the first aspect, once the braking state is reached, the rotational torque of the torsion spring 30 causes
Since the force of the brake mechanism 20 in the operating direction does not always act on the disc nut 13 to return to the idling state, the braking state can be reliably maintained even under a light load. That is, it is possible to prevent the load chain 11 from falling due to a light load.

Further, it is possible to easily and quickly switch between the braking state and the idling state. Especially when the idling state is switched to the braking state to wind up the chain, the idling handle 25 is operated consciously as compared with the conventional one. Since it is possible to save the trouble of restoring the braking state by the braking, it is possible to further improve the work efficiency.

According to the small tow hoisting machine of claim 2,
Operation setting of overload prevention mechanism 42 after the entire hoisting machine is assembled
Compared with the conventional one, the fine adjustment work of the fixed value is the idling handle
It saves you the trouble of disassembling and reassembling 25 etc.
Therefore, it is extremely practical.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1 showing a braking state.

FIG. 3 is an explanatory view of a main part in an idling state.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a sectional front view showing another embodiment.

FIG. 6 is a sectional view taken along the line BB of FIG. 5 showing a braking state.

FIG. 7 is an explanatory view of a main part in a idling state.

8 is a sectional view taken along line BB of FIG.

[Explanation of symbols] 1 Pinion shaft 13 Disc nut 20 Brake mechanism 25 Idling handle 27 Spring receiving member 29 Hole 30 Torsion spring 36 Spring 37 Ball 38 Notch 39 Feed handle 42 Overload prevention mechanism 53 Nut member

Claims (1)

[Claims] 1. A disk nut 13 on the pinion shaft 1.
Is screwed so as to be able to advance and retreat by screwing, the idling handle 25 is attached to one end of the pinion shaft 1 so as to rotate integrally, and the spring receiving member 27 is rotatably provided in the hole 29 of the disc nut 13. At the same time, the spring receiving member 27 is attached to the pinion shaft 1 so as to rotate integrally, and is interposed between the idling handle 25 and the disc nut 13.
Between the disc nut 13 and the spring receiving member 27, the disc nut 13 is connected to the brake mechanism through the screw connection.
A torsion spring that elastically urges to rotate in the 20 operating direction.
A feed handle 39 for rotating the disc nut 13 is attached to the disc nut 13, and a notch 38 for engagement is formed in the hole 29 of the disc nut 13, and the spring receiving member 27 is provided. In addition, the engaging ball 37 is elastically urged by the spring 36 and can be engaged with and disengaged from the engaging notch 38.
A small tow hoist characterized by having a.