JPS6243841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a formwork tightening device for molding concrete products.

A formwork for molding concrete products consists of a bottom frame and surrounding frames raised around the bottom frame, and at least one pair of surrounding frames can be opened and closed to facilitate demolding of concrete members. The molded formwork is known.

In order to mold a concrete member using such a formwork, it is necessary to tighten the above-mentioned openable and closable surrounding frame with a fastener.

Concrete is placed while vibrating the formwork using a vibrator, so if the pair of surrounding frames are tightened with the fasteners, if used for a long period of time, the abutting parts of the surrounding frames may wear out or vibrations may occur. Concrete gets deformed by entering the gap between the abutting parts, causing concrete leakage.

If elastic members are used as fasteners, tightening can be done easily, but when actually pouring concrete, the vibrations of the vibrator cause the members to expand and contract, making it difficult to tighten them. Concrete gets into the abutment area of both surrounding frames with each vibration, causing concrete leakage.

Therefore, the formwork tightening tool uses a rigid body with no elasticity as its member, and after tightening, both circumferential frames are integrated, and even if deformed or worn, the tightening width can be finely adjusted. Therefore, a structure that prevents concrete leakage is desired.

By the way, conventionally, formwork was tightened using long bolts and nuts, but when using such fasteners using long bolts and nuts,
Depending on individual differences, the tightening may be over-tightened or under-tightened, resulting in concrete leakage and impairing the durability of the formwork itself. Further, a lot of time and effort was required for tightening.

Thus, this invention was devised to address the above-mentioned conventional difficulties, and it is possible to assemble and disassemble the formwork with simple operations, thereby increasing work efficiency, and also to attach fasteners to the surrounding frame. To provide a formwork tightening device that uses a rigid member that does not expand or contract, which allows fine adjustment of the tightening width even after the tightening, and allows both tightened peripheral frames to be integrated after tightening. The purpose is to

The present invention will be explained below based on embodiments shown in the drawings.

First, the formwork tightening device according to the present invention includes a long bolt 1, a thick arm 2 having a substantially inverted U-shape, and a pedestal 3 having a U-shaped groove 3a having a width that allows the arm to be inserted therein. It is composed of. One end of the arm 2 is pivotally attached to one side of the pedestal 2 by a pin 6 passing through the side wall of the groove 3a.
It rotates around the axis and can be inserted into and retracted into the groove 3a. Further, a screw hole 5 is formed at the other end of the arm 2 so as to penetrate from the outside into the groove.
The tip of the long bolt 1 screwed into the screw hole 5 is the pin 6
It is formed so that it faces in the direction of , and is screwed so that the length of the screw insertion can be adjusted.

An insertion hole 9 is formed on the other side of the pedestal 2 to allow the pedestal 2 to rotate through the shaft 8 attached to the peripheral frame 11 of the formwork A through the side wall of the groove 3a. rotates around the shaft 8, and when the shaft 8 touches the bottom of the groove of the arm 2, the axis of the long bolt 1 is located below the center of the shaft as shown in FIG. has been done.

Note that in the embodiment shown in the drawings, a rotation operation hole 10 is provided in the axial direction at the bottom of the pedestal 3 and a rod-shaped body is inserted so that the pedestal 2 is rotated about the shaft 8; The rotating means is not limited to this.

Next, the state of use of this invention will be explained.

As shown in FIG. 2, a locking portion 12 is provided on one side of the surrounding frames 11, 11, which are capable of freely opening and closing the formwork A. The bolt head 1 of the long bolt 1 is attached to the locking portion 12.
Lock 3. Next, the pedestal 3 is rotatably attached to the other peripheral frame 11 by the shaft 8. Note that, on the contrary, the pedestal 3 may be attached to the surrounding frame 11 first, and then the bolt head 13 may be locked to the locking portion 12.

Next, arm 2 is rotated and tightened.

Here, if the tightening width is not appropriate,
Long bolt 1 screwed into female thread 5 of arm 2
Rotate to adjust the tightening width.

Thus, the present invention has the above-described configuration, and even after it is arranged on the peripheral frame of the formwork, the tightening width can be finely adjusted, and there is no need to bother with work such as determining the tightening width in advance. When the arm rotates and the shaft contacts the groove bottom, the center axis of the long bolt is below the shaft center axis, so the arm will not rotate and come off due to vibrations during concrete pouring. It is possible to securely tighten the formwork.

In this invention, the long bolt, the inverted U-shaped arm, and the concave pedestal are each formed as separate parts, and these parts are combined to form one fastener body. Even if a certain part is damaged during long-term use, it is only necessary to replace the damaged part, so the cost is very low and it can withstand long-term use.

In addition, since the arm and the long bolt are separate pieces, the arm can be made thick and rigid by casting only, making it easy to obtain the desired strength. Since the part absorbs bending force and the long bolt only generates tensile force, the overall strength and reliability are high, and it is recommended to provide a pedestal rotation operation hole that penetrates in the axial direction at the bottom of the pedestal. For example, a simple rod-shaped tool can be used as a rotating tool at the site, and is excellent in terms of adaptability and economy.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, and the first
The figure is a front view showing the tightening device, FIG. 2 is a perspective view showing the main parts of the tightening device according to the present invention, FIGS.
The figures are a plan view and a front view of the main parts, and FIGS. 5, 6, and 7 are sectional views. 1...Long bolt, 2...Arm, 3...Base, 4, 5...Screw, 6...Pin, 7...Mounting part, 8...Shaft, 9...Mounting hole, 10... Pedestal rotation operation hole, 11... Surrounding frame, 12... Locking part, A... Formwork.

Claims (1)

[Claims] 1. Consists of a long bolt, a thick-walled, approximately inverted U-shaped arm, and a pedestal having a U-shaped recessed groove wide enough to fit the arm, and the arm has one end is pivotally attached to one side of the pedestal by a pin that passes through the side wall of the groove, and is inserted into the groove so that it can freely protrude and retract, and the screw at the tip of the long bolt is inserted into the screw hole at the other end of the arm. When the insertion hole of the shaft attached to the formwork on the other side of the pedestal is formed through the side wall of the groove, and the shaft and the bottom of the groove of the arm are in contact with each other. A tightening device for concrete formwork, characterized in that the central axis of the long bolt is located below the central axis of the shaft.