JPH0241515B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a lever-type hoisting machine used to raise and lower cargo by operating a control lever.

Conventional technology Conventional devices of this type include, for example, the
The one disclosed in Publication No. 43398 is known.
In the device introduced in this publication, the drive member and the adjacent driven member are both screwed into threaded parts formed on the drive shaft, and the boss part of the driven member protrudes toward the drive member. is fitted with a ratchet wheel whose both sides are sandwiched between friction plates.
This ratchet wheel is locked to a ratchet pawl so that it can rotate only in the driving direction of the driven member, that is, in the winding direction of the load sheave, and is hooked onto the hook by repeatedly operating the operating lever in the left and right directions. The system is designed to intermittently lift and lower the loaded baggage.

Problems to be Solved by the Invention In the above-mentioned conventional device, when lifting and lowering cargo, the driven member screwed onto the drive shaft is fitted into the boss portion thereof and is latched to the ratchet pawl. Because of the rotating contact with the mating surface of the ratchet wheel, the ratchet wheel wears the inner peripheral surface of the hole. In order to eliminate this drawback, conventionally,
Ratchet wheels have been subjected to heat treatment.

However, when a ratchet wheel is heat-treated, both sides of the ratchet wheel do not come into uniform contact with the friction plate due to the quenching distortion that occurs on the side surfaces of the ratchet wheel. There was an inconvenience that both sides had to be polished parallel.

Means for Solving the Problems This invention was made to solve the above problems, and includes rotating a drive shaft by operating a control lever,
In a lever-type hoisting machine that moves a lower hook for hanging cargo in the vertical direction via a load sheave attached to the drive shaft, a pressing member having a ratchet wheel attached to the boss portion is fixed to the drive shaft. The engagement portion between the ratchet wheel and the pressing member, which is fitted into the boss portion of the driven member and engaged with the ratchet pawl, is formed in the radial direction of the two and has a groove that prevents the relative rotation of the two by a certain amount. One friction member is fitted into the boss portion of the pressing member on the driven member side facing the ratchet wheel, and the other friction member is fitted into the boss portion of the pressing member facing the pressing member and the driving shaft It is designed to fit into a boss portion on the drive member side that is fixed to the drive member.

Function Since the present invention has the above-mentioned configuration, when lifting or lowering a load by operating the operating lever, the ratchet wheel fitted to the boss portion of the pressing member is directly connected to the driven member that rotates together with the drive shaft. Since there is no contact and the movement relative to the pressing member in the rotational direction is restricted to a small amount, reducing the possibility of sliding, the inner circumferential surface of the hole in the ratchet is aligned with the boss of the pressing member. Some parts are no longer subject to wear effects.

Embodiment In FIG. 1, a load sheave 3 is rotatably held in the center of side plates 1 and 2 that are kept at a constant interval. Reference numeral 4 denotes a drive shaft that is integrally attached to the load sheave 3, and the drive shaft 4 has a right-handed thread 4a on a shaft portion protruding from one side plate 2. A driven member 5 is screwed into the drive shaft 4 on the side closer to the side plate 2, and a drive member 6 having a switching gear 6a is screwed on the side farther from the side plate 2.

A pressing member 7 is fitted into the boss portion 5a of the driven member 5 between the driven member 5 and the driving member 6, and the pressing member 7 has a claw on the boss portion 7A on the driven member 5 side. A wheel 8 and a friction member 9 are attached, and a friction member 10 is attached to the boss portion 7A on the drive member 6 side. As shown in FIG. 3, the ratchet wheel 8 has three engaging recesses 8a formed in the radial direction at equal intervals on the inner circumferential surface of the portion that is attached to the pressing member 7. As shown in FIG. On the other hand, a ratchet wheel 8 is provided on the outer peripheral surface of the boss portion 7A of the pressing member 7.
Three engaging protrusions 7a with slightly shorter lengths in the circumferential direction are formed to allow reciprocating rotation in the rotational direction within the engaging recesses 8a (Fig. 4a, Fig. 5). In addition, an annular notch 7b of a constant depth is provided on the outer circumference of the side surface in contact with the ratchet wheel 8. A spring 11 that presses the driving member 6 outward with respect to the driven member 5 is installed in the through hole of the pressing member 7 fitted into the driven member 5 . The drive shaft 4 is provided with a small diameter threaded portion 4b at its right end, and a washer 1 held by a nut 13 screwed into this small diameter threaded portion 4b.
2 prevents the drive member 6 rotated in the loosening direction from falling off the drive shaft 4.

Reference numeral 14 denotes a shaft fixed to the upper part of the side plates 1 and 2, and a ratchet pawl 16 that is pressed toward the ratchet wheel 8 by a spring 15 is attached to a portion of the shaft 14 protruding from the side plate 2. This prevents the ratchet wheel 8 from reversing when loading and unloading the load. Further, an upper hook 18 is provided on the shaft 14 between the side plates 1 and 2 via a connecting fitting 17. A load chain 19 is wound around the load sheave 3, and a lower hook 21 for hanging cargo is connected to the lower end of the load chain 19 via a connecting fitting 20.

The drive member 6 has a switching gear 6a portion accommodated within the operating lever 22. This control lever 2
2 is composed of an inner lever case 23 and an outer lever case 24 that are formed separately. The inner lever case 23 has a circular shape that includes a circumferential surface 23a that slides on the outer peripheral surface of the pressing member 7 and a locking surface 23b that has a circular opening 23c that is locked in the annular notch 7b of the pressing member 7. A protruding part is formed, and the inner lever case 23 has an outer peripheral part formed on the circumferential surface 2.
It is bent at right angles in the direction opposite to the protruding side of 3a. The outer lever case 24 is integrally connected to the inner lever case 23 by a plurality of screws 25 and nuts 26.
A circular opening 24a is provided in a portion corresponding to the operation grip 6b, through which the operation grip 6b is inserted without contact.

A rotational direction switching pawl 28 rotatably held by a shaft 27 with respect to both lever cases 23 and 24 is housed in the operating lever 22 on the lower side of the drive member 6 . Reference numeral 29 denotes a pressing member that urges the lower end of the rotational direction switching pawl 28 upward by a spring 30. The switching pawl 28 is connected to the switching gear 6 of the drive member 6.
Press a at all times. Also, on the right side of the side plate 2,
A brake cover 32 that covers the driven member 5, the friction member 9, the ratchet wheel 8, and the ratchet pawl 16 that engages with the ratchet wheel 8 has a plurality of screws 33 and nuts that keep the side plates 1 and 2 at a constant interval. 34 so that it does not come into contact with the inner lever case 23.

Since this embodiment is constructed as described above, when a load is applied to the lower hook 21 with the switching pawl 28 locked to the switching gear 6a, the load sheave 3 and the load sheave 3 are integrally attached to the lower hook 21. The drive shaft 4 is slightly rotated clockwise when viewed from the left side of FIG. Since the thread 4a of the drive shaft 4 has a right-handed thread, when the drive shaft 4 rotates slightly, the drive member 6, which is threaded onto the screw 4a but is prevented from rotating by the switching pawl 28, moves in the direction of the side plate 2, pressure is applied to the pressing member 7, ratchet wheel 8, and friction member 9 via the friction member 10, and the surface of the driven member 5, which is fixed in position by the stepped portion of the drive shaft 4, and Braking force is also applied during this period. Furthermore, at this time, since the ratchet wheel 8 is prevented from reversing by the ratchet pawl 16, neither the drive shaft 4 nor the load sheave 3 rotates after a slight rotation, and the load remains applied.

When the operating lever 22 is operated clockwise in this state, the rotation direction switching pawl 28 rotates the drive member 6 in the load lifting direction, so that the friction member 10, the pressing member 7, and the pressure member 7, which are rotated together by the drive member 6,
The ratchet wheel 8, the friction member 9, and the driven member 5 rotate the load sheave 3 in the load lifting direction and move the load suspended from the lower hook 21 to the operating lever 22.
Lift by the amount of operation. On the other hand, when the rotational direction switching claw 28 is engaged with the switching gear 6a in the opposite manner, the drive member 6 is moved to the right by the operation of the operating lever 22, and the friction member 10 is moved to the right.
Therefore, the friction member 10, the pressing member 7, the friction member 9, and the driven member 5 are rotated together with the drive shaft 4 in the direction of unloading the load by the load suspended from the lower hook 21, and the switching is performed. Claw 2
The drive member 6 whose rotation is prevented by the drive shaft 8 is pressed by the friction member 10 and moves the cargo downward until the rotation of the drive shaft 4 is stopped.

In addition, when changing the position of the load chain 19 freely in an unloaded state with no cargo hanging from the lower hook 21, first move the rotation direction switching pawl 28 to the neutral position shown in FIG. 1 using the handle 31. position and disengages from the switching gear 6a. Next, when the operating grip portion 6b of the drive member 6 is grasped and rotated counterclockwise, the drive member 6 is moved away from the friction member 10 with the help of the biasing force of the spring 11. When the movement of the drive member 6 is stopped by the washer 12 and you release your hand from the operation grip part 6b, the drive member 6, which is separated from the friction member 10 and released from the braking force, moves through the drive shaft 4. Since it idles together with the load sheave 3, the position of the lower hook 21 connected to the load chain 19 can be quickly and easily moved to any desired position.

Moreover, in this embodiment, the ratchet pawl 16
The ratchet wheel 8, which is locked to and can rotate only in one direction, is
The outer peripheral surface of the boss portion 7A of the pressing member 7 and the engaging uneven portion 7
Since they are connected by a and 8a and undergo almost no relative movement, the inner circumferential surface of the hole of the ratchet wheel 8 is hardly abraded by the pressing member 7.
Therefore, heat treatment of the ratchet wheel 8, which was conventionally required to prevent wear, can be omitted.

In addition, since no quenching distortion occurs in the ratchet wheel 8 by omitting heat treatment, when the ratchet wheel 8 is brought into uniform contact with the friction member 9, the side surfaces of the ratchet wheel 8 are ground parallel to each other to remove the quenching distortion. There is no need to go through the trouble of doing so.

Furthermore, the ratchet wheel 8 in which the pawl portion and the engagement recess 8a are formed can be punched out at once by simultaneous press working, resulting in good productivity, so that manufacturing costs can be reduced.

Effects of the Invention The present invention provides a lever-type winding machine in which a ratchet wheel, which is locked to a ratchet pawl so as to be able to rotate only in one direction, is attached to a pressing member fitted to the outer periphery of a boss portion of a driven member. At the same time, the pressing member and the fitting part of the ratchet wheel attached to the boss part thereof are connected by engaging uneven parts that are provided in the radial direction of both and restrict relative rotation between the two. Because they are connected, the rotation of the ratchet wheel relative to the pressing member is minimized when the load is unloaded, and the relative rotational sliding action of the two allows the inner circumferential surface of the ratchet wheel to Abrasion can be effectively prevented without subjecting the ratchet to heat treatment.

If the heat treatment of the ratchet wheel can be omitted, there is no need to remove the hardening distortion that occurs when the ratchet wheel is heat treated. It is possible to reduce the process and labor involved in polishing the side surface of the material to remove quenching distortion.

Furthermore, since the ratchet wheel provided with the engagement recess can be punched out efficiently by simultaneous press working, the number of man-hours for quenching distortion can be reduced, and the device can be provided at a low cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of one embodiment of the present invention;
3 is a plan view of the ratchet wheel, FIG. 4 is a drawing of the pressing member, where a is a plan view, b is a longitudinal sectional view, and FIG. 5 is a drive shaft, pressing member, ratchet wheel, FIG. 6 is a drawing of the inner lever case, where a is a longitudinal sectional view and b is a right front view of the same. 3... Load sheave, 4... Drive shaft, 5... Driven member, 5a... Boss portion of driven member, 7...
Pressing member, 7A...Boss portion of pressing member, 7a, 8
a... Engaging uneven portion, 8... Ratchet wheel, 9, 10... Friction member, 21... Lower hook, 22... Operating lever.

Claims (1)

[Scope of Claims] 1. A lever-type hoisting machine in which a drive shaft is rotated by operating a control lever and a lower hook for hanging cargo is moved vertically via a load sheave attached to the drive shaft, The pressing member having a ratchet wheel attached to the boss portion is fitted into the boss portion of the driven member fixed to the drive shaft, and the fitting portion of the ratchet wheel and the pressing member that engages with the ratchet pawl includes: An engagement uneven portion is formed in the radial direction of the two and restricts relative rotation between the two to a certain amount, and one friction member is a boss portion of the pressing member on the driven member side facing the ratchet wheel. The lever-type winding machine is fitted with a boss portion on the driving member side, and the other friction member is fitted with a boss portion on the drive member side that is fixed to the drive shaft facing the pressing member.