JPS6348637Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for locking a heavy object that is being lifted or lowered at an arbitrary position. Conventionally, with heavy lifting means that lifts and lowers tension bars via hollow hydraulic cylinders, when lifting and lowering work is performed continuously, it is necessary to constantly connect and disconnect the tension bars, resulting in very poor work efficiency. When a chain is used instead, it is easy to connect and disconnect, but there is a drawback that it is impossible to lock (hold) heavy objects at locations other than the connection points, that is, between the pins of the chain.

The present invention uses a special chain instead of a tension bar, and a screw is carved on the outer periphery (Fig. 2 A) or two sides (Fig. 2 B) of this chain, and a nut is screwed into the chain and its drive. This is a device that locks heavy objects at any position by placing the source at the bottom of the cylinder and the head of the hollow piston rod.

To explain the figure in detail, the hollow hydraulic jack consists of a cylinder, a hollow piston rod, a hollow guide, a rod cover screwed onto the cylinder head, and passes through a chain with a thread cut on the outer periphery. A lock nut is mounted on the piston rod head to be screwed into the outer peripheral thread of the chain, a gear is formed on the outer periphery of the lock nut, and a drive case consisting of an intermediate gear meshing with the gear, a driving pinion, and a hydraulic motor is attached. A drive case with similar contents is also suspended from the lower end of the cylinder. Each link of the chain constitutes a screw, which screws into the lock nut continuously and smoothly.

The lifting and lowering work is automatically performed in an inchworm-like manner by expanding and contracting the hollow piston rod while holding the heavy object alternately with the upper and lower lock nuts.

That is, the lock nut that holds the heavy object pulls up the heavy object suspended from the chain as the hollow piston rod extends, and at this time the lock nut' inside the drive case is rotated by hydraulic pressure in accordance with the rising speed of the chain.

With the above structure and operation, the present invention uses a bendable chain instead of an upright tension bar, so the chain can be wound up via a winding drum, and the chain can be easily connected or disconnected. This is a locking device for a hollow hydraulic cylinder, which is characterized by improved workability even more than a tension bar, and can be locked at any position.

[Brief explanation of drawings]

Figure 1 shows the second embodiment of the present invention.
The figures show the appearance of each chain. indicates a pulley.

Claims (1)

[Scope of utility model registration request] A hollow piston rod is penetrated by a chain with a thread carved on its outer periphery, and a nut is provided on each of the hollow piston rod head and cylinder bottom to be screwed into the thread of the chain, and a device is attached for rotating the nut. A locking device for a hollow hydraulic cylinder.