JPS6254754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overload prevention device for a traction and hoisting device.

Conventionally, small towing hoisting devices in which the load sheave is rotationally driven by swinging a manual handle have not been equipped with a safety device to prevent a load exceeding the allowable amount from being applied to the device. There was a risk that the gear mechanism of the device would be damaged by the load, leading to an unexpected accident. Recently, the above-mentioned handle has been divided into a handle body and a grip section, and when a load exceeding the allowable amount is applied to the device, the above-mentioned grip section swings and bends, preventing the operator from overloading. Some devices have been developed that are equipped with a sensing device to notify the user. However, even this sensing device merely senses an overload condition, but cannot actively avoid the overload condition, and still has the above-mentioned risks.

The present invention solves the above problems,
It is an object of the present invention to provide an overload prevention device for a traction hoisting device that can completely eliminate the above-mentioned danger by actively avoiding the overload state when a load exceeding the allowable amount is applied to the device. purpose. Therefore, the present invention is characterized in that, in a traction hoisting device that rotationally drives a load sheave through a ratchet mechanism by the swinging action of the handle, the above-mentioned handle is
It is composed of a handle body and a gripping part pivotably pivoted to the tip of the main body, and a lock mechanism for stopping the operation of the ratchet mechanism is disposed on the main body and interlocked with the gripping part. When the device is connected and a load exceeding an allowable amount is applied to the device, the grip portion swings and the locking mechanism is activated.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

In FIG. 1, reference numeral 1 denotes a manual handle for rotationally driving a load sheave 3 installed in a housing 2, and the handle 1 is pivotally mounted around the axis of a drive shaft 4. The swinging motion of the handle 1 is transmitted and converted into the rotational motion of the drive wheel 6 via the ratchet mechanism 5. The driving wheel 6 is screwed into a driven wheel 7, and the driving wheel 6 moves relative to the driven wheel 7 in its axial direction as the driving wheel 6 rotates. During hoisting, the drive wheel 6 rotates in the left direction A and is connected to the driven wheel 7 via the brake linings 8, 8 and the ratchet wheel 9, thereby transmitting the rotational force to the driven wheel 7. . Furthermore, during lowering, the drive wheel 6 rotates in the right direction B, and
The driven wheel 7 also rotates at an appropriate speed following the driving wheel 6 due to the lowering load applied to the load sheave 3. The driven wheel 7 is slidably spline-fitted to the drive shaft 4, and the driven wheel 7 and the drive shaft 4 move relative to each other in the axial direction and rotate integrally.

A pinion 10 is fixed to the tip of the drive wheel 4, and the pinion 10 is detachably connected to a gear mechanism 11 connected to the load sheave 3 (not shown). When the pinion 10 and the gear mechanism 11 are in mesh, the rotational movement of the drive shaft 4 is transmitted to the load sheave 3 via the gear mechanism 11, and the load sheave 3 is driven to hoist or lower. Ru. Further, when the pinion 10 and the gear mechanism 11 are in a disengaged state, the rotational movement of the drive shaft 4 is not transmitted to the load sheave 3, and the load sheave 3
is in an idle state around the axis of the drive shaft 4.

Reference numeral 12 denotes an idling mechanism for operating the load sheave 3 into an idling state, and the idling mechanism 12 includes a cam member 14 fixed to the rear end of the driven wheel 7 and a drive shaft 4.
It consists of an operating wheel 15 that is rotatably fitted onto the rear end portion and engages with the cam surface of the cam member 14.
Therefore, when the operating wheel 15 is rotated in one direction from the meshed state of the pinion 10 and the gear mechanism 11,
The operation wheel 15 moves in the right direction B as shown in the imaginary line by the action of the cam surface of the cam member 14, and the drive shaft 4 also moves in the right direction B, and the pinion 10
The gear mechanism 11 is in a disengaged state as shown by the imaginary line, and thus the load sheave 3 is in an idling state with respect to the drive shaft 4. Further, if the operating wheel 15 is rotated in the opposite direction to the above, the pinion 10 and the gear mechanism 11 will be brought into meshing state again due to the operation completely opposite to the above.

Reference numeral 13 denotes a pawl piece pivotally attached to the housing 2 so as to be able to swing freely. It prevents rotation in the lowering direction and acts to prevent the driven wheel 7 and by extension the load sheave 3 from reversing during hoisting, and the rotational force of the driven wheel 7 acts directly on the drive wheel 6 during lowering. to prevent

The ratchet mechanism 5, as shown in FIGS. 2 and 3, consists of a gear 17 and a pair of left and right pawls 18, 19. The gear 17 is connected to the driven wheel 7 as shown in FIG.
It is loosely fitted into the drive wheel 6 and screwed concentrically to the drive wheel 6 with a plurality of bolts 16. Further, the claw pieces 18 and 19 are swingably arranged opposite to the handle 1 via support shafts 20 and 21, and these claw pieces 18 and 19 are constantly separated from the gear 17 by resilient members 22 and 23, respectively. The bullet is biased in the direction of departure.
The claw piece 18 on the left side is for hoisting and engages with the gear 17 as shown by the solid line in FIG. 2 by the action of the cam 24.
Since only the swinging force of the handle 1 in the hoisting direction C is transmitted to the gear 17 via the hoisting claw piece 18,
The gear 17 and the driving wheel 6 rotate in the hoisting direction C, whereby the load sheave 3 is hoisted in the manner described above. Also, the claw piece 19 on the right side is the cam 2.
Due to the action of gear 1, as shown in the imaginary line in FIG.
7 for lowering, and when the handle 1 is swung during lowering, only the swinging force of the handle 1 in the lowering direction D is transmitted to the gear 17 via the lowering pawl 19. As a result, the gear 17 and the driving wheel 6 rotate in the lowering direction D, thereby driving the load sheave 3 to lower in the manner described above. The shaft 25 of the cam 24 projects to the outside of the handle 1, and an operating lever 26 is fixed to the projecting end of the shaft 25. The cam 24 can be rotated by appropriately switching the lever 26 as shown in FIG. operate the motion. Also, 29 is cam 2
4, and this mechanism 29 is the positioning mechanism of protrusion 3.
0 and a resilient member 31 that always elastically urges the protrusion 30 upward, and the tip of the protrusion 30 is elastically engaged with the cam 24 as shown in FIG. 24 operating positions are held as appropriate.

A locking piece 27 is integrally formed on the lever 26 as shown in FIG.
In cooperation with this, it functions as a stopper for preventing the operation of the idle rotation mechanism 12. That is, the locking piece 27
4, when winding up or down, the locking member 28 is located opposite to the front side, that is, on the right side in FIG. Idle mechanism 12 during lowering work
prevents it from operating due to incorrect operation.

As shown in FIGS. 2 to 4, the manual handle 1 includes a handle body 32 and a grip portion 33 pivotally attached to the tip of the body 32 via a pivot 34.
Consists of. 36 is a resilient member for fixing the grip portion 33 to the main body 32 when the load applied to the device, that is, the weight of the transported object is within the allowable range of the device; is interposed between a support portion 37 fixed to the tip of the main body 32 and a pressure receiving portion 38 provided at the upper end of the grip portion 33. As shown in FIG. 2, the upper end of the gripping portion 33 is pressed against the inner surface of the main body 32 and is fixed integrally with the main body 32 due to the elastic urging force of the elastic member 36. When winding up an object to be transported, even if the grip portion 33 is gripped and the handle 1 is swung, the fixed state is maintained by the resilient member 36. On the other hand, when attempting to hoist an object having a weight exceeding the allowable amount, the load applied to the main body 32 via the gear 17 of the ratchet mechanism 5 and the hoisting pawl 18 is applied to the elastic member 3.
In order to overcome the spring force of 6, the main body 32 remains as it is, and the grip part 33 is unable to maintain the above-mentioned fixed state, and swings and bends in the direction of arrow E with the pivot 34 as a fulcrum, as shown in FIG. to notify workers of overload conditions. In addition, since the upper end of the resilient member 36 is supported by the pressure receiving part 38 via the adjustment bolt 39,
By threading the bolt 39 back and forth as appropriate, the springing force of the springing member 36 can be adjusted to an optimum value.

Reference numeral 40 denotes a locking mechanism for stopping the operation of the ratchet mechanism 5 in conjunction with the swinging motion of the gripping portion 33. It consists of an actuating member 42 which is actuated. The driven member 41 is pivotally connected to the main body 32 via a support shaft 43, and has a first locking piece 44 that locks on the adjustment bolt 39 of the grip portion 33 at its lower end. They are curved, and second locking pieces 45 that lock into the lower end locking portions 46 of the actuating member 42 are formed at their upper ends. An elastic member 47 supported on the support shaft 43 is resiliently engaged with the first locking piece 44, and the locking piece 44 is always fixed in the locking direction with the adjustment bolt 39 by the elastic member 47. is being energized.
The resilient member 47 has the above function, that is, the driven member 4.
In addition to the resilient urging force in the swinging direction of 1, the function of pressing the driven member 41 against the inner surface of the main body 32 as shown in FIG. have Specifically, the actuating member 42 is made of a spring-like resilient member, and the actuating member 42 has its substantially central portion supported by a support shaft 48 fixed to the main body 32, and its upper end locking portion 49. It is inserted and locked into a locking hole 50 provided through the lowering claw piece 19 of the ratchet mechanism 5. In FIG. 3, when the gripping portion 33 swings in the E direction as described above during hoisting overload, the driven member 41 accompanies the swinging motion.
and the actuating member 42 in the F and G directions (second
(see figure), and further, the lowering claw piece 19 swings against the elastic force of the resilient member 23, and thus the claw piece 19 engages with the gear 17, locking the locking mechanism. 40 is in a locked state. In this locked state, both the hoisting claw pieces 18 and 19 for hoisting down engage with the gear 17, so even if the handle 1 is swung, the winding direction C will not change. The swinging force in the downward direction D also acts on the gear 17, and therefore the ratchet mechanism 5 does not operate, making it impossible to hoist the transported object. In addition, during the above swinging operation, the lowering direction D of the handle 1
When the grip part 33 swings and bends in the E direction as described above, it returns to the fixed state position with the main body 32 (see FIGS. 2 and 3) due to the elastic urging force of the elastic member 36. (see imaginary line), but the locking mechanism 40 maintains the above-mentioned locked state. That is, the driven member 41 of the lock mechanism 40 includes the main body 3.
2, a locking hole 51 having a larger diameter than the projection 52 is provided in correspondence with the locking projection 52 protruding from the inner surface;
In the above-mentioned locked state, the convex portion 52 protrudes into the locking hole 51 of the driven member 41 and locks, and the driven member 41 locks the resilient member 23 and the resilient member 47 of the lowering pawl 19. This prevents the locking mechanism 40 from returning to the reset state due to the rocking force. Then, this locked state is released and the locking mechanism 40
To return to the reset state, press the support shaft 43 of the driven member 41 in the direction of arrow H with your fingers in FIG. Then, as the support shaft 43 presses and moves, the driven member 41 also moves against the axial elastic biasing force of the resilient member 47, as shown by the imaginary line, and the convex portion 52 separates from the locking hole 51. As a result, the driven member 41 swings back until the locking piece 44 contacts and locks the adjustment bolt 39 of the gripping portion 33 due to the rotational urging force of the resilient member 47, and At the same time, the lowering claw piece 19 also swings away from the gear 17 due to the resilient urging force of the resilient member 23, and thus the lock mechanism 40 returns to the reset state. Then, when the finger is released from the support shaft 43, the driven member 41 and the support shaft 43 move in the direction opposite to the H direction due to the axial elastic urging force of the resilient member 47, and return to their original positions as shown by the solid line.

Therefore, during actual hoisting work, the object to be transported with a weight within the allowable range is
By grasping the gripping part 33 of and shaking it,
The object is hoisted or towed by normal operation, but when the weight of the object to be carried exceeds the allowable amount, when the handle 1 is attempted to swing by gripping the grip portion 33, the object swings in the hoisting direction C. At this time, the handle body 32 remains as it is, and the grip part 33 swings and bends in the E direction to notify the operator of the overload condition, and at the same time, the locking mechanism is activated in conjunction with the swinging movement of the grip part 33. 40 is activated, thereby stopping the operation of the ratchet mechanism 5 to prevent damage to the gear mechanism, etc. of the device due to the above-mentioned overload.

It should be noted that the present invention is of course not limited to the above-described embodiments, and is open to various design changes. For example, in the embodiment described above, the ratchet mechanism 5
has a pair of left and right hoisting claws 18 and 19, and a locking mechanism 40 is connected to and operated by the hoisting claws 19, but the ratchet mechanism 5
It is also preferable to use other configurations as long as they have the same function. In this case, it is also preferable to have a configuration in which the lock mechanism 40 is not connected to the pawl of the ratchet mechanism 5 but directly stops the operation of the ratchet mechanism 5. . Also, the structure of the lock mechanism 40 and the grip portion 33 of the handle 1, and the configuration of these 40, 33.
The connection structure of the two can also be changed as long as they have the same function.

The present invention has the configuration as detailed above,
The intended purpose was effectively achieved. In particular, the handle 1 is composed of a handle body 32 and a gripping part 33 pivotably attached to the tip of the main body 32, and the gripping part 33 swings when a load exceeding an allowable amount is applied to the device. A locking mechanism 40 for stopping the operation of the ratchet mechanism 5 is disposed in the main body 32, and the locking mechanism 40 works in conjunction with the swinging movement of the gripping part 33. Therefore, when the weight of the object to be transported exceeds the allowable amount of the device, the gripping portion 33 bends to notify the operator of the overload condition, and the locking mechanism 40 operates to actively prevent It is possible to completely prevent the gear mechanism from being damaged and causing an unexpected accident by making the hoisting operation of the device impossible. Moreover, since the structure is extremely simple, it can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of a traction and hoisting device using one embodiment of the present invention, and FIGS. 2 and 3 are sectional views taken along the line X--X in FIG. 1 showing the above embodiment. FIG. 2 shows the hoisting operation state of the ratchet mechanism, and FIG. 3 shows the operation stop state of the ratchet mechanism. FIG. 4 is a side sectional view of the above embodiment in the state shown in FIG. 3, and FIG. 5 is a partial front view of the above apparatus. DESCRIPTION OF SYMBOLS 1...Handle, 3...Load sheave, 5...Ratchet mechanism, 32...Handle body, 33...Gripping part,
40...Lock mechanism.

Claims (1)

[Claims] 1 The ratchet mechanism 5 is activated by the swinging action of the handle 1.
In the traction and hoisting device for rotationally driving the load sheave 3 through Lock mechanism 40 for stopping the operation of 5.
is disposed on the main body 32 and interlocked with the gripping portion 33, so that when a load exceeding an allowable amount is applied to the device, the gripping portion 33 swings and the locking mechanism 40 is activated. An overload prevention device for a traction hoisting device.