Elephant Chain Block Co., Ltd.

Munenobu Honda

Yoshio Ueno

Yasuo Wada

Haruo Kubota

Yoshio Nishi

Masaru Fujikawa

Kazunori Tsuda

One of the hand wheel and the brake ratchet wheel is provided with a cover portion extending toward the other thereof and having a circular peripheral surface which covers the lining plate, and the other of the hand wheel and the brake ratchet wheel is provided with a circular opposite peripheral surface opposed to the circular peripheral surface, so that opposite peripheral surfaces of those circular peripheral surfaces can be arranged adjacently to each other or have a scaling member interposed therebetween. Therefore, even when dust and rainwater enter a wheel cover for a hand wheel, these dust and rainwater can be prevented from further entering a mechanical brake.

Manual chain block

In a manual chain block with a driving shaft a wheel cover 15 is provided with a radial bearing 18 for supporting the driving shaft 7 at one axial end portion. The driving shaft 7 has an actuating mechanism side shaft portion for supporting an actuating mechanism 20 extended so as to be supported by the radial bearing 18, so that shaft deflection can be decreased at the time of actuating operation of the actuating mechanism 20.

A manual hoist and traction machine wherein an outer diameter of a first lining plate constituting a mechanical brake is made smaller than an inner diameter of a driven disc of a handwheel. The outer diameter of a second lining plate and of a driven disc are made smaller than an inner diameter of a cylindrical portion of a braking ratchet wheel, and the first and second lining plates are formed of a lining raw material having improved performance with a compressive strength of 15 (Kgf/mm.sup.2) or more and a maximum strain of 12 (10.sup.-3 mm/mm) or more.

Manual hoist and traction machine

An elastic hoist and traction apparatus in which a friction receiving surface is provided at a rotor of a motor, and an overload prevention device is provided at the reverse side to a load on a brake for stopping a driving shaft and between the motor shaft and the friction receiving surface of the rotor or between the motor shaft and the driving shaft, thereby solving the problem created in that the overload prevention device is provided at the load side of the brake.

Electric hoist and traction apparatus

A hoist and traction machine having a mechanical brake (13), wherein a not-relative (14)-rotatable operating handle (18) is axially movably an interposed between a stopper (17) provided at an axial end of a driving shaft (5) and a driving member (8) threadedably engaged with the driving shaft (5). Between the operating handle (18) and the stopper (17) there is provided an elastic biasing member (19) for biasing the operating handle (18) toward the driving member (8) The operating handle (18) is provided with engaging projections (31), the driving member (8) is provided with free rotation control surfaces (35) in elastic contact with the engaging projections (31) respectively, and the free rotation control surfaces (35) are formed in gradient surfaces for applying resistance against movement of the driving member (8) in the return direction with respect to free rotation operation by the operating handle (18) so as to enable the free rotation control state to be held up to a desired value, whereby an input range of a pulling force of a chain during the free rotation control is expanded without reducing operability of free rotation operation.

Free rotation control apparatus for a hoist and traction machine

A hoist and traction machine having a load sheave, a driving shaft and a driving member which is screw-threadedly engageable with the driving shaft. An operating handle 16 has an inner plate 16a and a brake cover 13a to cover a mechanical brake. The inner plate and the brake cover both have apertures of about the same size through which passes a portion of the driving member. A sleeve 102 which is separate from the brake cover and the operating lever is received in the apertures and held in place by a flange and a retaining ring so as to facilitate easy assembly.

Hoist including brake cover and operating lever coupling

A hoist and traction machine having a free rotation control device/apparatus for selectively controlling the mechanical brake to be inoperative and for maintaining the inoperative mode of the mechanical brake, so as to control the free rotation of the load sheave. The free rotation control device is designed such that improved free rotation control operation can be provided, and the range of the pulling force for the chain can be enlarged in the controlled free rotation of the load sheave; thus, allowing the chain to be pulled quicker, while requiring little operating skill. Further, free rotation operation is not provided when the load sheave (and thus the driving shaft) is subjected to a large load acting in the direction of hoisting down the load, thus achieving highly improved safety.

Hoist and traction machine with free rotation control

A mechanical brake for a hoist and traction machine, which is provided with brake releasing force control layers at braking surfaces of a driving member opposite to lining plates. Each of the brake releasing force control layers comprising a heat-treated plating layer made of nickel phosphate, nickel chromium or chromium, so that the surface condition of each braking surface of the driving member can be controlled and the surface hardness can be controlled, whereby an initial force for the brake releasing during the lowering of a load or the releasing traction of a load is adapted to be lower.

Mechanical brake for a hoist and traction machine

A hoist and traction machine having a mechanical brake, in which an operating handle is non-rotatably and axially movably interposed between a stopper provided at an axial end of a driving shaft and a driving member screwable with the driving shaft. Between the operating handle and the stopper is provided a regulation unit for regulating a relative rotation range of the driving member with respect to the driving shaft so as to enable release of the regulation by moving the handle away from the driving member, so that the driving member is moved away from a driven member by of moving the operating handle from the driving member to be normally rotated in a free-rotation operation mode whereby the braking action of the mechanical brake by a braking ratchet wheel and braking plates is released to control the free rotation of the driving shaft and the elastic biasing member biases it to maintain the state of free rotation control.

A hoist having an overload protection device is provided with a locking mechanism between a hoist body and a disc hub at a mechanical brake provided at the hoist body, the locking mechanism utilizing forward screwing of a driving member forming part of the mechanical brake to lock rotation of the disc hub during an overload condition.

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Osaka Sayama, Japan

Munenobu Honda