JPH0130760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a safety device for a lever-type or hand-chain-type traction hoist.

[Prior art and its problems] Conventionally, as a safety device for preventing forcible towing or hoisting exceeding a predetermined limit value, for example,
No. 48-40316 is known, but when the load exceeds a certain limit, the claws of the switching pawl plate disengage from the special tooth profile of the switching wheel, causing the lever to idle.
Although this idling of levers and hand chains may seem reasonable at first glance, it was extremely dangerous when working at heights. In other words, if a worker at a high place is pushing down or pulling the lever or hand chain of a towing hoist with all his might, and the lever or hand chain suddenly spins, he may become dazed and fall, resulting in an accident resulting in personal injury. There was a danger of letting it happen.

[Means for solving problems]

The safety device for a traction hoist of the present invention is a safety device for a traction hoist equipped with a drive transmission member that transmits rotational torque on the side of an operating member such as a lever or a hand chain, wherein the drive transmission member has an outer periphery; A main body having an uneven surface formed thereon and a shaft center hole serving as a screw hole for screwing into a screw of a drive shaft; and being able to slide in sliding contact with the uneven surface of the main body and move in the inner and outer radial directions;
If the rotational torque is less than the predetermined limit value, the abutting portion is moved by the elastic force of the elastic member interposed between the uneven surface and the fixed portion such as the inner circumferential surface of the housing cover. When it comes into contact with the concave portion of the uneven surface and forms a predetermined gap with the fixing portion, and the rotational torque exceeds a predetermined limit value, the corresponding contact portion corresponds to the convex portion of the uneven surface. and a movable member that sequentially moves in the outer radial direction against the elastic force of the elastic member, presses against the fixed portion, and does not move the operating member.

[Effect]

With the above configuration, if the rotational torque is less than the predetermined limit value, the driving force transmission member can rotate because a predetermined gap is formed between the movable member and the fixed portion. Furthermore, when the rotational torque reaches a predetermined limit or more, the movable member sequentially moves in the outer radial direction and presses against the fixed part, preventing the operating member from moving, thereby eliminating the possibility of the operating member slipping unexpectedly during operation. .

〔Example〕

Hereinafter, the present invention will be explained in detail based on drawings showing examples.

FIG. 1 shows a towing hoist according to the present invention, and this towing hoist has an operating member 1 such as a lever or a hand chain.
Drive transmission member 2 that transmits rotational torque on the side
0.

The drive transmission member 20 is composed of a main body 20a whose shaft center hole is a screw hole 24 that is screwed into the screw 10 of the drive main shaft 8, and a movable member 20b which is movable in the inner and outer radial directions, When the rotational torque reaches a predetermined limit value or more, the operating member 1 is not moved.

Further, a brake desk hub 11 is screwed onto the screw 10 of the drive main shaft 8. That is, this hub 1
1 is integrally composed of a small diameter cylindrical part 13 and a large diameter disc part 14, and two brake discs 15 and 16 are fitted onto the outer peripheral surface of the small diameter cylindrical part 13. , 16, a ratchet desk 17 is disposed as a clamp. This ratchet desk 17 has many inclined teeth 1 on the outer periphery.
8, and the claw (not shown) is always connected to the tooth 18 by a spring.
It is elastically pressed to the side and allows rotation in only one direction. A cover 28 is fixed to the inner peripheral surface of the bolt 29 in the housing 2.

Therefore, the main body 20a has an uneven surface 3 on the outer peripheral surface.
5 is formed, and the inner end surface abuts against the brake disk 16. Furthermore, the movable member 20b is shown in FIGS. 2 and 3.
As shown in the figure, the resilient member 27 interposed between the uneven surface 35 and the fixing portion 30 on the inner peripheral surface of the cover 28 is resiliently biased in the inner radial direction. It consists of a rod-shaped body. Specifically, the movable member 20b
is disposed in the radial direction on the outer cylinder body 20c that is externally fitted onto the main body 20a, and a contact portion 38 at the tip thereof slides into contact with the uneven surface 35 using the resilient member 27. The elastic member 27 is housed in a hollow elastic member storage chamber 40 provided in the outer cylinder 20c, and is locked to an outer collar 41 of the movable member 20b. 31 is an uneven tooth portion provided on the outer peripheral surface of the outer cylinder body 20c,
A tip claw portion 33 of a lever pawl 32, which is attached so as to be movable in the axial direction of the operating member 1, is removably locked therein.

Thus, if the rotational torque m is small and is less than the predetermined limit value, the abutting portion abuts against the recess 37 of the uneven surface 35 to form a predetermined gap A with the fixed portion 36. In other words, the driving force transmission member 20 is rotatable.

Further, when the rotational torque M becomes larger than a predetermined limit value, the contact portion 38 moves from the concave portion 37 of the uneven surface 35 to correspond to the convex portion 38, as shown in FIG. 3, and the movable member 20b moves. The movable member 20b moves in the outer radial direction against the elastic force of the elastic member 27, and the predetermined gap A becomes zero, and the outer end of the movable member 20b is connected to the fixed part 3 of the housing 2.
0 to brake rotation. In other words, the operating member 1
is not movable.

Next, FIGS. 4 to 7 show other embodiments,
This driving force transmission member 20 includes a main body 20a having a wavy uneven surface 35 on a part of its outer circumference, and this uneven surface 3.
A roller-shaped movable member 2 disposed in the recess 37 of 5
0b, and an outer cylindrical body 20c that is fitted onto the outside and holds a number of roller-shaped movable members 20b via elastic members 27 such as plastic or rubber, and the outer cylinder body 20c is made of Then, an inner collar protruding from the inner circumferential surface of the housing 2 is provided as a fixing part 30.
As shown in the figure, there is a predetermined gap A, but when the rotational torque M reaches a predetermined limit value or more, the resilient member 27 is compressed and the movable member 20b moves in the outer radial direction and presses against the fixed part 30. The rotation of the driving force transmission member 20 is stopped.

It should be noted that the present invention is of course not limited to the above-described embodiments, but, for example, this safety device may be freely applied to a hand chain wheel type towing hoist. Furthermore, the fixed part to which the movable member 20b is pressed is
It is also possible to use members other than the housing 2 and the cover 28, and it is also possible to interpose a wear-resistant member between them.

〔Effect of the invention〕

The safety device for a towing hoist according to the present invention has the above-described configuration, so that if the load is below a predetermined limit value, the load is hoisted by operating the operating member 1 such as a lever or hand chain. When the load exceeds a predetermined limit value (overload), the movable member 20b is pressed against the fixed part 30 and braked even if the operating member 1 is not operated, thereby preventing damage to the gear mechanism, etc. It can play a role in security, and in particular, when a worker is climbing up to a high place and pushing and pulling the operating member 1, there will be no accidental idling, and if the operating member 1 is overloaded, it will stop. This has the great effect of completely preventing the danger of workers falling from a high place, as well as preventing unexpected shocks and allowing smooth operation.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of essential parts showing one embodiment of the present invention, Fig. 2 is a sectional view taken along line DD in Fig. 1 with some parts omitted, and Fig. 3 is an overload FIG. 4 is an enlarged sectional view of the main part of another embodiment, and FIG.
The figures are a cross-sectional view taken along the line E-E in FIG. 4, FIG. 6 is a cross-sectional view of the same during overload, and FIG. 7 is a cross-sectional view taken along the line H-H in FIG. 4. DESCRIPTION OF SYMBOLS 1... Operation member, 2... Housing, 8... Drive main shaft, 10... Screw, 20... Drive transmission member,
20a... Main body, 20b... Movable member, 27...
Resilient member, 28...cover, 30...fixing part, 3
5... Uneven surface, 37... Concave portion, 38... Contact portion,
39...Protrusion.

Claims (1)

[Scope of Claims] 1. A safety device for a traction hoist equipped with a drive transmission member 20 that transmits rotational torque on the side of an operating member 1 such as a lever or hand chain, wherein the drive transmission member 20 is A main body 20a is formed with an uneven surface 35 and has a shaft center hole as a screw hole 24 that is screwed into the screw 10 of the drive shaft 8, and is movable in the inner and outer radial directions by slidingly contacting the uneven surface 35 of the main body 20a. At the same time, if the rotational torque is less than a predetermined limit value, the elasticity of the elastic member 27 interposed between the uneven surface 35 and the fixed part 30 such as the inner peripheral surface of the housing 2/cover 28 will be reduced. Due to the force, the contact portion 38 contacts the recess 37 of the uneven surface 35 to form a predetermined gap A with the fixed portion 30, and
When the rotational torque exceeds a predetermined limit value, the corresponding contact portion 38 corresponds to the convex portion 39 of the uneven surface 35 and moves sequentially in the outer radial direction against the elastic force of the elastic member 27. A movable member 20b that presses against the fixed part 30 and prevents the operating member 1 from moving. A safety device for a traction hoist.