Abstract: The present invention provides an overload-preventing device for a winch, by which even an overload is caused to descend. The overload-preventing device includes an accommodation hole that is formed in a rotation drive member and is open in the contact plane with a pressing drive member and accommodates a movable piece pressing member and a movable piece. The movable piece is pressed to the side of the pressing drive member by the movable piece pressing member. An engagement groove having a depth in which approx. half of the movable piece can be driven is formed at a part of the contact plane of the pressing drive member. The unwinding side of the engagement groove is formed at the fitting plane while the winding-up side thereof is formed on the inclined surface.

Abstract: A lever hoist with an overload preventing device comprises a pressing member for rotatably pressing a pressed member via a reverse rotation preventing ring and a pair of friction members, and a rotation drive member capable of transmitting rotating force of a chain wheel to the pressing member and movable in an axial direction. The rotation drive member is urged toward the pressing member by a disk spring. Locking teeth are formed at surfaces facing each other, of the pressing member and the rotation drive member, respectively. Respective pressed surfaces during a hoisting-down operation, of the locking teeth are sharply inclined, while respective pressed surfaces during a hoisting-up operation are moderately inclined. A rotation limiting member is interposed between the rotation drive member and the disk spring. Even if the rotation drive member is rotated in an overload state, the rotating force of the rotation drive member cannot be transmitted to the disk spring and a nut.

Abstract: The object is to provide a chain hoist with an overload prevent device, ensuring an easy and secure adjustment of load limit numerical values. It comprises a pressing drive member 8 for pressing and rotating a pressure receive member 7 by way of a backstop wheel 11 and friction members 9 and 10, and an axially displaceable, rotary drive member 14 adapted to transmit a rotational force of a hand chain wheel 15 to the pressing drive member. The rotary drive member is urged toward the pressing drive member by a belleville spring 24. The pressing drive member and the rotary drive member have lock teeth 80 and 140 that are formed on their respective confronting faces. The lock teeth 80 and 140 include steeply sloped wind-down press faces 80a and 140a, respectively, and gently sloped wind-up press faces 80b and 140b, respectively.

Abstract: A hoist is a hoisting device wherein a pressure receiving member 6 rigidly secured to a drive shaft 5 is rotated by a press drive member 7 through a reverse rotation stop ring 10 and a pair of friction members 8,9 disposed on both sides of said stop ring. The member 7 is formed with a spring-loading hole 71 opening at the axially base side for accepting the tip 13d of a left hand coil spring 13 and a second engaging groove 7e opening at the axially base side extending radially outwardly. The groove 7e is inclined in the wind-down direction as it approaches the axially forward surface. The angle .alpha. formed between the wind-down directional inclined surface 7k of said groove 7e and the axially backward surface 7j of said member 7 is an acute angle.

Abstract: A lever-type hoist comprising a pressure receiving member 6, a press drive member 7 adapted to press-drive the pressure receiving member 6 through friction members 8, 9 and a reverse rotation stop ring 10, and a coil spring 13 interposed between the pressure receiving member and press-drive member, the base engaging portion 13b of coil spring 13 being engaged by an engaging groove 6d of pressure receiving member and the tip engaging portion of coil spring 13 being engaged by an engaging surface 7k of press-drive member, with an inclined surface 7h formed in the wind-up side of the engaging surface 7k.

Abstract: If the load applied on the load sheave is small, the pressing drive member contacts tightly with the friction members to make secure the braking of rotation of the drive shaft, so that the small load is prevented from moving downward by its own gravity, and moreover the operation wheel is engaged with and held in the rotation limiting member spline-coupled with the drive shaft so as to be free to idle even in a no-load state, and a spring for pressing the operation wheel to the rotation limiting member is inserted between the outer end surface of the operation wheel and the spring retainer held on the drive shaft projecting from the rotation limiting member.

Abstract: In an unloaded state, by pulling the pressing drive member apart from the pressure bearing member by moving to the operation wheel side, the load sheave is allowed to rotate freely without disengaging the pinion of the drive shaft and the load sheave. In this lever operated hoist, at this time, since the conical friction member to be engaged with the pressing drive member in the rotating direction, and the intermediate member spline-coupled on the drive shaft adjacently to this conical friction member respectively have engaging parts to be engaged with each other in the rotating direction, disposed at their confronting ends, these engaging parts are engaged with each other when the load sheave rotates freely, and the contact of the torque transmitting member and other constituent members is effectively prevented, so that the load sheave is permitted to idle continously and smoothly.

Abstract: A lever-operated hoist having a structure for continuously lowering the lower hook side chain and end side chain of load chains in no-load state comprising a pressure drive member movably screwed in the axial direction on a drive shaft, a rotation limiting member spline-fitted on the drive shaft adjacently to the pressure drive member, and an operation wheel rotatably disposed on the rotation limiting member, a first projection and a second projection extending in the radial direction are disposed at specified intervals in the circumferential direction at the outer end face in the axial direction of the pressure driving member, two circumferential spaces are divided and formed by them, and the rotation limiting protuberance of the rotating limiting member and the pressure release protuberance of the operating wheel are projecting into these two spaces.

Abstract: A lever-operated hoist with an operation lever support structure capable of operating smoothly, especially in the horizontal position. The operation lever has an inner tubular part which is slidably and rotatably supported in or on the a tubular part of the brake cover. A tubular assembly member is radially inward of the innermost of these tubular parts and has flanges at the ends to arrest and hold the tubular parts against movement in the axial direction of a drive shaft of the hoist.

Abstract: A hand-operated chain block which is lightweight and simplified in the structure of the hand chain wheel portion, and safe and smooth in the hand chain operation is provided with a hand chain wheel cover for covering the upper, lower and front parts of the hand chain wheel, and a hand chain guide cover for covering the sides of the hand chain wheel such that the entire circumference of the hand chain wheel is covered. The hand chain guide cover is a one-piece body folded and formed from one metal plate, comprising drooping parts for guiding the UP side and DOWN side of the hand chain, and a bottom part for coupling the lower ends of the drooping parts. Upper support parts are formed in the upper end portions of the drooping parts and are inserted and supported on the upper stays, and a lower support part formed in the middle of the bottom part of the hand chain guide cover is positioned and supported on the lower stay.

Abstract: A lever type hoist the lower hook of which can be positionally adjusted with a continuous lowering of the load chain on the end side under the no-load condition.

Abstract: A hand-operated chain block having a hand chain wheel portion light in weight and simplified in construction and which permits safe and smooth hand chain operation. A hand chain wheel cover is mounted on a plurality of stays disposed on side plates of a chain block body in such a manner as to cover the upper, lower and front portions of the hand chain wheel, and a pair of hand chain guide plates are mounted on an upper pair of stays to cover the side portions of the hand chain wheel, thereby covering substantially the entire periphery of the hand chain wheel. Each of the hand chain guide plates is formed of one metal plate in a folded pattern, and the pivotal support portion at its upper end part is inserted into the upper stay, and the hand chain guide plate is oscillatably suspended and supported, while a hand chain wound around the hand chain wheel is inserted through a hand chain guide portion formed at the lower end portion so as to be guided.

Abstract: A lever-operated hoist chain equipped with a cargo chain slip-out preventive mechanism. A slip-out preventive member linked to the unloaded side end part of a link chain in a hoist chain is made of a metal block excelling in impact resistance, and has a width greater than the interval between both side plates of the main body frame. Therefore, whether the load applied on the cargo lifting hook is large or small, if the let-off of the link chain unexpectedly exceeds the limit and the free end part side is excessively drawn out to the load side having the hook, the slip-out preventive member abuts against the outer circumference of the both side plates of the main body frame, and securely blocks the slip-out of the link chain free end part, so that the safety of the work is guaranteed.

Abstract: A hand-operated chain block having a hand chain wheel portion light in weight and simplified in construction and which permits safe and smooth hand chain operation. A hand chain wheel cover having a leftwardly laid-down U-shaped configuration which covers the upper, lower, and front portions of the hand chain wheel is mounted on a plurality of stays disposed on side plates of a chain block body, and hand chain guide plates are mounted on the upper right and left ones of the stays so as to cover substantially entire periphery of the hand chain wheel. Each of the hand chain guide plates is formed of one metal plate in a folded pattern. A pivotal support portion formed in a crooked pattern on the top end portion of each hand chain guide plate is inserted through one of the upper stays.

Abstract: A lever type hoisting machine capable of easily and securely pulling down a lower hook in no-load state. An operation wheel is rotatably supported in contact with a drive shaft and a pressure drive wheel, and an inside collision part and an outside collision part are disposed at the pressure drive wheel side part of the operation wheel and at the opposite side part, respectively, while a collision wall capable of being engaged with the inside collision part is formed on the pressure drive wheel, and a collision element capable of being engaged with the outside collision part is formed in a regulating member held movably only in the axial direction on the drive shaft in contact with the opposite side of the pressure drive wheel of the operation wheel, and a secure rotation in the hoist-down direction of the pressure drive wheel in no-load state is guaranteed, so that it is possible to pull down the lower hook in continuous state.

Abstract: A manual hoist with overload preventer wherein rotation in the winding direction under overload is automatically arrested; however, when an overload develops after hoisting or pinching of a load, unwinding is possible. The apparatus includes an operation ring, and a friction ring and a drive ring both being capable of engaging the operation ring. When the driving ring is turned in the winding direction, the operation ring remains engaged with both the friction ring and the drive ring, enabling the relative rotation of the drive ring and the friction ring. When the drive ring is turned in the unwinding direction, the drive ring and the friction ring are rotated as a unit through the operation ring.

Abstract: In a hand hoist in which a driven member 15 and a biasing drive member 16 are threaded onto a driving shaft 11, an overload avoiding arrangement for the hoist, which is so arranged that a manually rotated member 21 is supported by a support frictional surface 16d of the biasing drive member 16 and a frusto-conical frictional surface 22b of a frusto-conical friction member 22, while the frusto-conical friction member 22 unrotatably supported on the biasing drive member 16 so as to be displaceable in an axial direction, is depressed in the direction of the support frictional surface of the biasing drive member 16, by an adjustable nut 26 of the outer end of a boss 16a of the biasing drive member 16 and a belleville spring 23.

Abstract: A U-shaped suspension ring is pivotally supported on a horizontal pin inserted through a suspension shaft supported by the top plate of a load suspending tripod or by a support member disposed at a high place. In order to lift a chain block to the position of the suspension ring, a rope passed around the hook of the chain block is divided into a hook lifting rope portion extending around the opposite ends of the horizontal pin and tension rope portions to be pulled from the ground.

Abstract: A hand hoist or pulling apparatus including a drive clutch assembly, and a drive shaft and transmission gears associated with the assembly for pulling a chain on a load sheave by oscillating a lever. A holding member and a stop lever for preventing the member from movement are provided to hold a pinion on one end of the drive shaft in meshing engagement with the transmission gears and also to hold the pinion disengaged therefrom when the drive shaft is shifted. The holding member is held stationary against rotation, mounted on the clutch assembly and restrained from axial movement by the stop lever which is biased by a spring and pivotally mounted on a side plate.