JPH0223384Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a step embedding device for a manhole formwork.

Concrete manholes usually have U-shaped steps on the inner wall for people to climb up and down. In order to form such a step, a window is provided in the inner frame of the formwork, a closing plate that fits within the window is detachably attached, and the arm of the step passes through between the lower edge of the window and the closing plate. A hole is formed, the arm of the step is passed through this hole, and its tip is exposed between the outer frame and the inner frame. Concrete is poured into this part and allowed to harden. After hardening, the outer frame is removed. At the same time, the closing plate of the inner frame is removed and the solidified concrete manhole is pulled upward.

Conventionally, the closing plate has been installed and removed by extending a screw rod behind the closing plate and turning the screw with a handle to move the closing plate toward the inner frame or backward. However, it takes a considerable amount of time to rotate the screw rod with the handle to move the closing plate into and out of contact with each other, and in order to install these devices within the inner frame, various accompanying equipment is naturally required. This led to high cost of formwork. Also,
In conventional embedding devices, a semicircular notch is provided between the lower edge of the opening and the closing plate, and the step is supported by being inserted into the circular hole formed by aligning the notches. With this kind of support, not only is the position of the step shifted and the step is not embedded horizontally to a predetermined length in many cases, but also it is often impossible to remove the closing plate from the mold due to leakage.

The present invention was devised in view of these points, and its purpose is to make it possible to easily set the step, to prevent the step from leaking without shifting the set position, and to easily remove the closing plate. This invention relates to a step embedding device for manhole formwork that can be installed and removed.

The following description will be given with reference to the drawings. Reference numeral 1 denotes a cylindrical inner frame of a manhole form. Although the outer frame is not shown, it is placed on the bottom plate 2 surrounding the inner frame 1, leaving room for concrete injection, and is surrounded by the inner frame 1, the outer frame, and the bottom plate 2. Unset concrete is poured into the chamber. In the drawings shown as examples, the inner frame 1 is represented by a slanted wall, but the inner frame 1 may have a straight wall type.

3 is an opening formed on the circumferential side of the inner frame 1.
A plurality of openings 3 are provided at different levels, and include both those whose upper edges are open at the upper edge of the inner frame 1 and those whose upper edges are window-shaped. If the inner frame 1 is a straight wall, the upper edge of the inner frame 1 will be an opening, but if the inner frame 1 is a slanted wall type, the lower opening will be opened as shown in the figure. 3 may be a window type, and the upper opening 3 may be of an upper edge open type.

A support plate 4 is provided horizontally on the back side of the lower edge of this opening 3.
is protruded, and a first rubber plate 5 made of hard rubber is installed on top of this. First rubber plate 5
A groove 8 is bored in the upper surface into which only the lower half of the base 7 of the U-shaped step 6 fits. However, the first
Instead of extending the rubber plate 5 all the way to the rear, the groove 8 may be formed long enough to support only the arm 9 of the step 6.

On the other hand, 10 is a rotating body, which is rotatably attached to the support plate 4 via a hinge 11. This rotating body 10 has a second rubber plate 12 and a closing plate 13.
, whose surfaces are equal to the shape of the truncated opening. When the rotating body 10 rotates from the solid line position to the dotted line position in FIG.
A groove 8' is provided to fit into the upper half of the step 6 which is fitted into the groove 8 of the second rubber plate 5, and the closing plate 13 completely closes the opening 3 together with the front surface of the second rubber plate 12. Close tightly. A rotating body 10 is placed inside the opening 3.
When it is fitted, the second rubber plate 12 and the closing plate 13
The front surface of the opening 3 is adapted to match the continuous surface of the inner frame 1, and the closing plate 13 is formed with a step 14 that fits snugly with the edge of the opening 3, thereby ensuring airtightness. It is desirable that

Since the present invention is constructed as described above, the setting in step 6 involves tilting the rotating body 10 backward and opening the groove 8 of the first rubber plate 5 visible under the opening 3.
Fit the base 7 of the step 6 inside. At this time, the free end side of the step 6 is located outside the inner frame 1 (see FIGS. 1 and 2). After doing this, the fourth
The rotating body 10 is rotated in the direction of the dotted line in the figure. As a result, the base 7 of the step 6 is elastically compressed and firmly supported between the grooves 8, 8' of the first and second rubber plates 5 and 12, and the base 7 of the step 6 is firmly supported. The contact surfaces 5 and 12 are almost watertight. Further, the closing plate 13 completely and tightly closes the opening 3 with the front surface of the second rubber plate 12 (see FIG. 1).

In this state, if you place the half frames of the outer frame from both sides on the bottom plate 2 and tighten both half frames with clamps, etc., a chamber for concrete pouring will be formed between the outer frame, inner frame, and bottom plate. , put the fatty tuna here and wait for it to solidify.

When the concrete solidifies, the outer frame is first removed, and then the rotating body 10 is tilted backward to be removed from the opening 3 (see solid line in Figure 4). Rotating body 1
0 may be adhered to concrete, but a hammer may be used to break the adhesion. When such work is carried out, there will be no obstruction above the base 7 of the step 6 protruding from the inner wall of the manhole, so the concrete product is lifted upward and demolded from the inner frame 1.

As described above, in the present invention, the support plate 4 and the first rubber plate 5 are provided for setting the step 6, a groove 8 is bored in the rubber plate 5, and the step 6 is set along the groove 8. If you rotate the rotating body 10 toward the inner frame 1 side, step 6
The base 7 of the rubber plate 5, while fitting into the grooves 8, 8',
Since it is fixed elastically between the holes 12, there is no risk of displacement due to external force, and leakage can be prevented as much as possible.

Furthermore, since the opening 3 is opened and closed by rotating the rotary body including the closing plate 13 via the hinge 11, the operation is extremely simple and no special equipment is required, so that it can be manufactured at low cost. It is possible.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the inner frame with the step set and the opening closed by the rotating body, and Figure 2 is
FIG. 3 is a front view of the inner frame showing a state in which the rotating body is tilted horizontally backward, and FIG. Partially enlarged cross-sectional view when the body is tilted horizontally backward,
FIG. 5 is a perspective view of the step. 1...Inner frame, 2...Bottom plate, 3...Opening, 4...
Support plate, 5...first rubber plate, 6...step,
7... Base, 8, 8'... Groove, 9... Arm, 1
0... Rotating body, 11... Hinge, 12... Second rubber plate, 13... Closing plate, 14... Step portion.

Claims (1)

[Scope of utility model registration request] In a manhole formwork consisting of a cylindrical outer frame, an inner frame, and a bottom plate connecting these at the bottom, concrete is injected and solidified into the chamber formed by these, and the inner frame has a plurality of openings arranged at different levels. A support member is installed to horizontally support the first rubber plate inward from the lower edge of each opening, and on this rubber plate there is a groove into which only the lower half of the base or arm of the U-shaped step fits. On the other hand, a rotating body is rotatably supported via a hinge attached to the rear of the support plate, and this rotating body consists of a second rubber plate and a closing plate, the front surfaces of which are , which is equal to the opening shape, closes the opening as a continuous surface of the inner frame when the rotating body is rotated in the direction of the inner frame, and has a second
A step embedding device for a manhole form, characterized in that a groove formed on the lower surface of the first rubber plate is fitted into the upper half of the step fitted into the groove of the first rubber plate.