CN-122009999-A - Braking device, lever block and ratchet mechanism

Abstract

A brake device (70) is provided with a brake bracket (71) which is rotatably supported by a drive shaft (25) and has a flange (71 a) and a boss (71 b), a female screw member (35) which is rotatably supported by the boss (71 b) and is screwed with a male screw portion (26) on the outer periphery of the drive shaft (25), a ratchet (80) which is sandwiched by the flange (71 a) and the female screw member (35) which are opposed to each other and has a ratchet (83) which restricts the rotation direction to one direction on the outer periphery, brake plates (71 a, 72 b) which are disposed between at least one of the flange (71 a) and the female screw member (35) and the ratchet (80), and a pair of pawl members (90) which are engaged with the ratchet (83) and are disposed at symmetrical positions around the drive shaft (25), and a ratchet (80) having high and low teeth 831) protruding from the center (832).

Inventors

• KITA AKINORI

Assignees

• 株式会社开道

Dates

Publication Date

20260512

Application Date

20210128

Priority Date

20200414

Claims (5)

1. 1. A ratchet mechanism comprising a ratchet wheel having a plurality of ratchet teeth formed on the outer periphery thereof and at least two pawl members engaged with the ratchet teeth, wherein the ratchet wheel is allowed to rotate in only one direction, The ratchet mechanism is characterized in that, The ratchet is provided with high teeth and low teeth having a lower protruding height from the rotation center of the ratchet than the high teeth, On the ratchet, the high teeth and the low teeth are alternately arranged, the high teeth and the low teeth are alternately adjacent and the pitches in the circumferential direction are set equal, At the same time, at least one other of the pawl members engages another of the tooth valleys between adjacent ratchet teeth when the pawl member engages the tooth Gu Buka between adjacent ratchet teeth.
2. 2. The ratchet mechanism according to claim 1, wherein, When one of the pawl members engages the tooth Gu Buka on the back side of the high tooth, at least another of the pawl members engages the other tooth Gu Buka on the back side of the low tooth.
3. 3. The ratchet mechanism according to claim 1 or 2, wherein, The two pawl members are arranged at symmetrical positions about the rotation axis.
4. 4. The ratchet mechanism according to claim 3, wherein, The ratchet teeth are provided with an odd number of 2 times.
5. 5. The ratchet mechanism according to any one of claims 1 to 4, wherein, The tip-side low tooth tip portion of the low tooth is formed as a part of an arc.

Description

Braking device, lever block and ratchet mechanism (The application is the division of patent application entitled "brake device, lever block and ratchet mechanism". In the application: the application made by Kagaku Kogyo Co., ltd., china application No. 202180028007.2, application date 2021, month 01 and day 28.) Technical Field The invention relates to a braking device, a lever handle and a ratchet mechanism (RATCHET MECHANISM). Background In order to perform operations such as lifting and lowering a load, or fixing a load (tightening a load) by a hoist chain or the like, lever blocks are widely used. The lever block can perform winding (reeling) and rewinding (unreeling) of the chain by operating the lever by hand. As such a lever block, for example, a type shown in patent document 1 is known. In the lever block disclosed in patent document 1, a driving member is driven by operating an operation lever, and a drive shaft is rotated by the driving member, whereby a load pulley is rotated. Thereby, the cargo can be lifted or unloaded. The lever block is provided with a switching knob, and the switching operation of the switching knob can switch between the winding direction and the rewinding direction when the driving force is transmitted from the operation lever. [ Prior Art literature ] [ Patent literature ] Patent document 1 Japanese patent application, JP 2011-102182A Disclosure of Invention (Problem to be solved by the invention) However, when the switching knob is erroneously switched to the winding direction side during the winding operation of the lever block, the brake mechanism may not function. Specifically, if the switching knob is erroneously switched to the winding direction in a state where the tip of the pawl member is in contact with the tip of the ratchet teeth of the ratchet wheel, the ratchet wheel may start to rotate violently under the load of the load. When the tip of the pawl member is brought into the gap between the ratchet teeth at the stage where the ratchet starts rotating, the rotation of the ratchet can be stopped. However, if the ratchet wheel is rotated strongly by switching the switching knob in a state where the tip of the pawl member is in contact with the tip of the ratchet wheel, the next ratchet wheel (next tooth) may come earlier than the time required to enter the tooth bottom, and the pawl member collides with the tip of the next tooth to spring up, and then the same state occurs, and the tip of the pawl member may not enter the tooth bottom, and the rotation of the ratchet wheel may not be stopped. The structure disclosed in patent document 1 cannot prevent the rotation of such a ratchet. The present invention has been made in view of the above circumstances, and an object thereof is to provide a brake device, a lever block, and a ratchet mechanism capable of preventing reverse rotation of a ratchet. (Means for solving the problems) In order to solve the above-described problems, according to a first aspect of the present invention, there is provided a brake device for preventing reverse rotation of a load pulley by stopping reverse rotation of a drive shaft that transmits rotation to the load pulley around which a chain is suspended. The braking device has the following features. The brake device is provided with a brake bracket which is rotatably supported by a drive shaft and has a flange portion and a boss portion, a female screw member which is rotatably supported by the drive shaft and is screwed with a male screw portion provided on the outer periphery of the drive shaft, a ratchet wheel which is sandwiched by the flange portion and the female screw member which are opposed to each other and has a ratchet for restricting the rotation direction to one direction on the outer periphery side, a brake plate which is arranged between at least one of the flange portion and the female screw member and the ratchet wheel, and at least one pawl member which has a tip side engaged with a tooth Gu Buka located between adjacent ratchet teeth and is engaged with the ratchet wheel, and a high tooth and a low tooth which protrudes from the rotation center of the ratchet wheel to a height lower than the high tooth are provided on the ratchet wheel. In the above-described invention, it is preferable that the pawl member is provided in a pair, and the pair of pawl members are arranged at symmetrical positions about the drive shaft. In addition, in another aspect of the present invention, it is preferable that in the above invention, the ratchet is alternately provided with high teeth and low teeth. In the present invention, the number of the ratchet teeth is preferably 2 times the number of the ratchet teeth. In the above-described invention, the low-tooth-tip end portion on the low-tooth-tip side is preferably formed as a part of an arc. In order to solve the above problems, according to a second aspect of the present invention, there is provided a lever block having the follo