JPH0352804Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a sheave block with a rope breakage prevention device that is applied to intermediate supports of hauling ropes used for pulling out or transporting strands during suspension bridge cable construction work. This is related to.

(Prior Art) The hauling rope 1 used for the construction work of suspension bridge cables is as shown in FIGS. 9 and 10.
A carrier 2 constituting a transport device is fixed in the middle of the rope 1, and is configured to transport strands and other materials suspended from the carrier 2 by moving the hauling rope 1 in the longitudinal direction.

The carrier 2 is normally fixed to the hauling rope 1 by means of a carrier clamp 3. As will be described later, the carrier clamp 3 has a spindle shape in order to pass through the sheave block. When the hauling rope 1 extends over a long span, support structures (not shown) are provided at appropriate intervals in the longitudinal direction of the rope, and the middle of the hauling rope 1 is supported by the support structures. There is. The sheave block is fixed to the support structure and used for the purpose of supporting the hauling rope 1 while allowing the rope or the carrier clamp 3 to move freely.

FIG. 5 shows a conventional sheave block, in which reference numeral 4 denotes a mounting member that is attached to the support structure via a pin, and an upper frame 6 having an upper sheave 5 axially mounted on both ends thereof is fixed to the middle part of the mounting member 4. At the lower end, a lower framework 8 with a lower sheave 7 pivoted on both ends is connected to a pin 9.
are connected via.

As shown in FIGS. 7 and 8, when the hauling rope 1 moves in the direction of the arrow and the carrier clamp 3 passes through the sheave block,
The lower framework 8 swings about the pin 9, and the lower sheaves 7 at both ends of the framework 8 are displaced up and down, allowing the carrier clamp 3 to easily pass through the sheave blocks.

(Problem to be solved by the invention) However, in this case, in the conventional sheave block, the lower sheave 7 does not have restoring force, so after the carrier clamp 3 passes, the upper and lower sheaves 5 and 7 remain spaced apart. There is a risk that the hauling rope 1 may deviate from the upper and lower sheaves 5 and 7.

For this reason, as shown in FIG. 6, a leaf spring 10 is attached to give the lower sheave 7 resilience, but since the lower sheaves 7, 7 are connected to each other, the movement of each individual sheave is is affected by the movement of other sheaves, and there is a risk that the rope may fall off.

(Means for solving the problem) The present invention is an attempt to solve the above problem, and the present invention is to solve the above-mentioned problem. It is characterized by being equipped with a movable sheave that is movable along the members, and an urging member that always moves the movable sheave toward the framework. An object of the present invention is to provide an improved sheave block which can be freely displaced in accordance with the movement of a rope or a carrier clamp, and which prevents the sheave block from coming off the rope.

(Function) In the present invention, as described above, a plurality of sheave mounting members are arranged on the sheave block framework on which the fixed sheave is mounted, and the sheave mounting member has a movable sheave that is movable along the sheave mounting member. , and an urging member that always moves the movable sheave toward the framework, so that when a carrier clamp having a larger diameter than the hauling rope passes between the fixed sheave and the movable sheave, The movable sheave moves along the sheave mounting member against the biasing force of the biasing member and away from the framework on which the fixed sheave is mounted, thereby allowing passage of the carrier clamp.

After passing through the carrier clamp, the movable sheave is returned to its original position by the biasing member.

Since each movable sheave independently performs the above-described movement, the hauling rope and carrier clamp smoothly pass through the sheave block without coming off the rope.

(Effect of the invention) As described above, in the sheave block according to the present invention, each movable sheave is attached to a plurality of sheave mounting members disposed on the sheave block framework on which fixed sheaves are mounted, respectively. The movable sheave is mounted so as to be movable, and each movable sheave is individually provided with an urging member, and each movable sheave can be freely displaced in accordance with the movement of the rope or carrier clamp, and It is possible to prevent cables.

(Example) The present invention will be described below with reference to the illustrated embodiments.

In FIGS. 1 and 2, numeral 11 is a sheave block framework on which a pair of left and right upper fixed sheaves 12 are pivoted, and numeral 13 is a mounting portion for connecting the framework to another support structure with a pin.

A pair of left and right cylinders 14 constituting the above-mentioned sheave mounting member are suspended from the framework 11, and a long hole 15 is vertically bored in the outer peripheral wall near the center of the cylinder 14. A shaft 17 on which a lower movable sheave 16 is mounted is slidably loosely fitted, and the coaxial shaft 1
The base end of the cylinder 7 is supported by a bearing 19 that moves up and down within the cylinder 14 using a vertical shaft 18 fixed to the lower portion of the cylinder 14 as a guide. Further, a coil spring 20 wound around the vertical shaft 18 is interposed between the bearing 19 and the inner bottom surface of the cylinder 15.
An upward force is constantly applied to the bearing 19 and the lower movable sheave 16 by the urging force of the coil spring 20.

Note that the coil spring 20 constitutes a biasing member for the movable sheave 16.

In the embodiment, the hauling rope 1 and the carrier clamp 3 are connected to an upper fixed sheave 12 and a lower movable sheave 16 as shown in FIGS. 3 and 4.
The distance between the two sheaves 12 and 16 in the vertical direction is normally maintained at a distance that allows the hauling rope 1 to pass through.

When the carrier clamp 3, which has a larger diameter than the hauling rope 1, passes between the two sheaves 12 and 16, the shaft 17 and bearing 19 of the lower movable sheave 16 resist the biasing force of the coil spring 20 and press against the cylinder 14. The lower movable sheave 16 is pushed down along the
is displaced downward to allow the carrier clamp 3 to pass through.

After the carrier clamp 3 has passed, the lower movable sheep 16 returns to its original position due to the biasing force of the coil spring 20.

Since the lower movable sheave 16 performs the above-described movements independently, the hauling rope 1 and the carrier clamp 3 can be prevented from coming off.
Can pass through the sieve block smoothly.

As described above, according to the embodiment, the left and right cylinders 14 are vertically disposed on the sheave block frame 11.
The lower movable sheaves 16 are mounted so as to be movable up and down along the cylinder 14, and each lower movable sheave 16 is equipped with a coil spring 20 that always applies an upward force to the sheave 16. Each of the lower movable sheaves 16 independently connects the hauling rope 1
By configuring it so that it can be freely displaced according to the movement of the carrier clamp 3, the hauling rope 1 and the carrier clamp 3 are prevented from coming off.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of a sheep block with a rope escape prevention device according to the present invention, and Fig.
3 and 4 are respectively front views showing the operating state of the sheave block of the present invention, FIGS. 5 and 6 are front views of the conventional sheave block, and FIGS. FIG. 8 is a front view showing the operating state of a conventional sheep block, FIG. 9 is a front view of a hauling rope, and FIG. 10 is a side view thereof. 11... Sheave block framework, 12... Upper fixed sheave, 14... Cylinder, 16... Lower movable sheave, 20... Coil spring.

Claims (1)

[Scope of utility model registration request] A plurality of sheave mounting members disposed on a sheave block framework on which a fixed sheave is mounted are provided with movable sheaves that are movable along each of the sheave mounting members, and a force that causes the movable sheaves to always move toward the framework. A sheave block equipped with a rope breakage prevention device, which is equipped with a member.