JPH0738587Y2 - Pulley device for telescopic columns - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) A telescopic column that expands and contracts by sequentially raising and lowering a plurality of elevating columns nested in a fixed column fixed on the ground by winding and unwinding a wire rope. In the above, the winding drum for winding the wire rope is fixed to the fixed lower part, and the wire rope pulled out from this is folded back via the pulley device attached to the fixed upper part and stored in the fixed column. It is guided to the lower end of the lifted column in the first stage. The present invention relates to an improvement of this pulley device.

(Prior Art) In a telescopic column of a type in which a wire rope is wound to raise a first-stage lifting column housed in a fixed column on the ground, a winding drum is provided below the fixed column. The wire rope to be wound around is hung around a pulley device provided on the fixed upper part and guided to the lower end part of the first-stage lifting column, where it is folded back again through the pulley and hung on the upper part of the fixed column. Be stopped. Thus, in the conventional pulley device, the bracket that supports the pulley is fixed to the fixed column.

(Problems to be solved by the invention) In the pulley device, since the wire rope is wound smoothly on the winding drum in sequence, the winding position of the wire rope is axially moved on the drum according to winding or unwinding. Need to move. However, in the conventional sheave device, since the direction of the sheave is fixed, the wire rope may be slanted on the sheave depending on the winding position. For this reason, smooth winding of the wire rope is hindered, and the wire rope bites into the lower layer portion or irregular step winding occurs. For this reason, the wire rope may be damaged or may be subjected to an unreasonable impact due to slippage from the step winding portion, and in the worst case, the wire rope may come off the pulley.

Therefore, an object of the present invention is to provide a pulley device for a telescopic column that can change the direction of the pulley by following the movement of the winding position of the wire rope with respect to the winding drum.

(Means for Solving the Problems) In order to solve the above problems, in the present invention, the fixed column T ₁
The bracket 2 is rotatably and horizontally pivotally attached to the upper end of the pulley 3, and the pulley 3 is horizontally supported on the bracket 2. As the wire rope R moves axially on the winding drum D, the pulley 3 is moved left and right. The pulley device 1 for a telescopic column was constructed so as to swing.

(Operation) In the pulley device for a telescopic column of the present invention, when the wire rope R is wound or unwound by the winding drum D, the winding position of the wire rope R moves on the winding drum D in the axial direction. Then, when the extending direction of the wire rope R changes, the bracket 2 is rotationally displaced horizontally, and the pulley 3 follows the extending direction of the wire rope R. Therefore, the pulley 3 does not impede the movement of the winding position of the wire rope R on the winding drum D, and the wire rope R is wound around the pulley without largely deviating in direction.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings.

In FIG. 5, a telescopic column T has a vertically fixed column T ₁ whose lower portion is buried in the ground, and a plurality of lifting columns T ₂ , T ₃ , ... There is. Fixed column T ₁
The hoisting machine M is provided at the lower portion, and the pulley device 1 is provided at the upper end portion. The first-stage lifting column T ₂ has a pulley P at the lower end. The wire rope R pulled out from the winding drum D of the hoisting machine M is folded back downward through the pulley device 1 and fixed column.
It passes through the inside of T ₁ and is hung around the pulley P of the elevating column T ₂ of the first stage, folded back again and locked to the upper part of the fixed column T ₁ . Therefore, when the wire rope R is wound or sent out by the hoist M, the first-stage elevating column T ₂ is moved up and down.

As shown in FIGS. 1 to 3, the pulley device 1 comprises a bracket 2 on which a pulley 3 is axially supported, and the pulley 3 is horizontally mounted on a fixed column so as to be swingable.

The bracket 2 has a box shape that surrounds the upper and lower sides and both sides of the pulley 3 and has an open front and back. Pivots 2a, 2a vertically project from the upper and lower parts of the bracket 2.

On the other hand, bearing plates 4 and 5 are horizontally provided at the upper end of the fixed column T _{1 so} as to face each other vertically. The upper bearing plate 4 has a notch recess 4a into which the pivot 2a of the bracket 2 is inserted and then the retaining plate 6 prevents the pivot 2a from coming off. The lower bearing plate 5 has a bearing hole 5a into which the lower pivot 2a of the bracket 2 is inserted. Further, between the bearing plates 4 and 5 of the fixed column T ₁ , an opening 7 for receiving the pulley 3 in a horizontally rotatable manner is provided.

Next, the operation of the above embodiment will be described. When the telescopic column T is telescopically operated by the hoisting machine M, the take-up drum D takes up or sends out the wire rope R. At this time, the winding position of the wire rope R moves in the axial direction on the winding drum D, and the extending direction of the wire rope changes. On the contrary,
The bracket 1 is horizontally rotated about the pivots 2a, 2a so that the pulley 3 of the pulley device 1 extends along the extending direction of the wire rope R. Therefore, the pulley 3 always properly receives the wire rope R along the extending direction. Further, the movement of the wire rope R on the winding drum D is not hindered by the pulley 3, and there is no possibility that the wire rope R will come off the pulley 3. The wire rope R is evenly and regularly wound around the entire drum surface. Therefore, the expansion / contraction operation of the expansion / contraction column T can be smoothly performed.

(Effect of the Invention) As described above, according to the present invention, the bracket 2 is horizontally rotatably and pivotally attached to the upper end of the fixed column T ₁ , and the pulley 3 is horizontally supported on the bracket 2 for the telescopic column. Since the pulley device 1 is configured, the pulley 3 horizontally swings along the wire rope extending direction following the movement of the wire rope R on the winding drum D in the axial direction. There is no danger of coming off the pulley 3. Further, since the wire rope R is uniformly and uniformly wound around the entire drum surface, the wire rope R is smoothly sent without being damaged, and the telescopic column T can be smoothly expanded and contracted.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a plan view of a pulley device for a telescopic column, FIG. 2 is a front view thereof, FIG. 3 is a side view thereof, and FIG. 4 is a winding drum. A front view, FIG. 5 is a side view of the telescopic column, and FIG. 6 is a front view of the same. 1 ...... pulley device 2 ...... bracket 3 ...... pulley D ...... winding drum T ₁ ...... fixed column T ₂ ...... lift columns T ...... expandable column

Claims (1)

[Scope of utility model registration request] 1. An extendable column that expands and contracts by raising and lowering a plurality of elevating columns nested in a fixed column by winding and rewinding the wire rope, for winding the wire rope fixed to the lower part of the fixed column. It is a pulley device for folding the wire rope pulled out from the take-up drum at the upper part of the fixed column and guiding it to the lower end of the first-stage lifting column in the fixed column, which is pivotally attached to the upper end of the fixed column. An extendable column that is composed of a horizontally rotatable bracket and a pulley supported by the bracket, and is characterized in that the pulley swings horizontally as the rope moves axially on the winding drum. Pulley device.