JPH0221206Y2 - - Google Patents

Description

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

Manholes are equipped with U-shaped steps for people to ascend and descend through them, but these steps are formed at the same time as concrete is poured in concrete forms. Conventionally, this step was embedded by providing a window in the inner frame of the formwork, inserting the base of the step embedded inside the manhole product into this window, and blocking the window to prevent leakage from inside. This was done by screwing the plates together and, after the concrete had solidified, unscrewing them and removing the plates. However, in order to install and remove this board, the operator must enter the inner frame and work, and in order to screw and fix the board to the window, a corresponding complicated process is required. The device must be installed inside the inner frame, which not only increases the cost of the manhole formwork, but also reduces the accuracy of step installation. Another point that has been criticized for a long time is that it takes a considerable amount of time to install and remove the boards that block the windows.

In view of these points, the present invention aims to provide a manhole formwork that allows steps to be easily installed on the outside of the inner frame, that can be removed extremely easily and in a short time, and that is inexpensive. The main purpose of this is that in a manhole formwork that has a chamber for forming a manhole by a cylindrical outer frame, an inner frame, and a bottom plate that connects these at the bottom, the inner frame has an uneven height. A recess is provided, and a fitting body is provided within the recess, the outer surface of which is flush with the surface of the inner frame and which can be inserted and removed in a substantially vertical direction, and the recess has a side wall and a bottom wall that extend inward. An engaging part is formed on this side wall to prevent the fitted body from coming off in the horizontal direction, and a hard rubber plate is laid on the bottom wall, and the base or arm of the U-shaped step is placed on this rubber plate. On the other hand, the fitting body has a rubber plate with a groove formed on the bottom surface that contacts the base of the U-shaped step or the upper half of the arm when it is fitted into the recess. It is characterized in that it is provided on the lower surface of the bottom wall.

The following description will be given with reference to the drawings. Reference numeral 1 indicates an inner frame of a manhole form whose side walls are inclined walls. 2 is
Although the outer frame is not shown, this is the bottom plate, which surrounds the inner frame 1 in a concentric circle, and connects the inner frame and the outer frame at the bottom. is formed. The outer frame is divided horizontally and is tightened with clamps when set up. Reference numeral 3 denotes two recesses formed at different levels on the side surfaces of the inner frame 1, and the recess 3 has at least a side wall 4 and a bottom wall 5, and has a back wall 6 if necessary. An upward wedge-shaped engaging portion 7 is provided on the side wall 4 in a protruding manner.
engages with a female engaging portion on the side wall of the fitting portion, which will be described later, to prevent the fitting portion from slipping out forward. Bottom wall 5
A rubber plate 8 made of hard rubber is laid on the top surface of the base 9' of the U-shaped step 9.
A groove 10 is bored into which the lower half of the . Rubber plate 8
It is not necessarily necessary to provide the grooves over the entire surface of the bottom wall 5, and in some cases, the grooves 10 may be provided only to a slightly deeper position from the front edge of the bottom wall 5, so that the grooves 10 do not have a U-shape. , two grooves may be cut into which only the arm 11 of the step 9 is fitted.

On the other hand, 12 is a fitted body whose front wall 13 fits flush with the outer surface of the inner frame 1 into the recess 3 so that it can be inserted and removed in a substantially vertical direction. This fitted body 1
A side wall 14 extends rearward from the front wall 13 of 2, and is provided with a female engaging portion 15 that engages with the wedge-shaped engaging portion 7. A rubber plate 17 is provided on the bottom wall 16 of the side wall 14. is provided below, and a groove 18 is bored in its lower surface into which the upper half of the base 9' is inserted into the step 9 when it is fitted. The depth of the rubber plate 17 may also be shortened so that there are only two grooves on each side so that only the arm portion 11 of the step 9 can fit into the grooves 18.

Since the present invention is constructed as described above, as shown in FIG. into this recess 3 from above. When inserted all the way down, the engaging parts 7 and 15 engage with each other, preventing the fitting part 12 from coming off forward. The upper half of the step 9 corresponds to the groove 18 of the rubber plate 17 provided on the lower surface of the bottom wall 16 of the fitting body 12.
covered with. In this way, the front wall 13 of the fitted body 12 forms a part of the circumferential surface of the inner frame 1, and only the free end of the step 9 faces outside the inner frame 1, and the step 9 has upper and lower rubber parts. The plates 8 and 17 are compressed.

It is desirable that the fitting between the fitting body 12 and the recess 3 be made a little tight, but if the concrete is uniformly solidified by applying vibration when pouring concrete, it is thought that the fitting body 12 may float if only a strong fit is applied. However, in such a case, as shown in FIG.
Windows 20 and 21 communicating with the recess 3 are provided, and the fitting body 12 is placed in the recess 3 using a clamp 22 that uses the back wall 6 as a fulcrum.
It may be tightly clamped inside. It is easier to perform this work before setting the outer frame.
After setting step 9 as described above, the outer frame is placed on the bottom plate 2 and tightened with clamps, and a chamber for concrete pouring is formed between the outer frame, the inner frame and the bottom plate. In this way, unsolidified concrete is placed in this chamber and allowed to harden. After solidification, the outer frame is removed and the concrete product is pulled upwards. Step 9
The part facing the room has solidified inside the concrete product, so when the whole is lifted, the inner frame 1 and the concrete product will separate, but the fitted body 12
Since it is located above the step 9, it escapes from the recess 3 together with the concrete product and is lifted up while adhering to the inside of the concrete product. Once the concrete product has been lowered to the ground, the fitting body 12 can be removed from the product. Product and mating body 12
may not be removed by hand due to the adhesive action of concrete, but the adhesion is only between the front wall 13 of the fitted body 12 and the inner wall of the product, and can be easily removed by tapping with a hammer.

As described above, in the present invention, the recess 3 is provided in the inner frame 1, and the fitting body 12 that is fitted from the outside is used to form the step 9 between the recess 3 and the fitting body 12.
Since the base 9' or arm 11 of the
The setting work of the step 8 can be performed from the outside of the inner frame 1, and since it is sufficient to just insert it in the vertical direction, the work can be performed extremely easily and quickly.
In addition, unlike conventional products, there is no need to equip the interior of the inner frame with a complicated loading/unloading device, which is advantageous in terms of manufacturing time and parts, and the cost is low. Furthermore, since the step is held by the narrow pressure between the rubber plates 8 and 17, so-called leakage can be prevented, and
By replacing the rubber plates 8, 17 with various grooves 10, 18, it can be applied to various steps.

[Brief explanation of the drawing]

Figure 1 is a front view of the inner frame of the formwork, and Figure 2 is the front view of the inner frame of the formwork.
3 is a perspective view of the step set in one of the recesses, FIG. 4 is a perspective view of the fitting body entering the upper recess, and FIG. FIG. 6 is a perspective view of the fitting body that fits into the lower recess, and a partial cross-sectional view of the embodiment in which a clamp is attached. 1...Inner frame, 2...Bottom plate, 3...Recess, 4...
Side wall, 7... Engaging portion, 8... Rubber plate, 9... Step, 9'... Base, 10... Groove, 11... Arm, 12... Fitting body, 13... Front wall, 14... ...Side wall, 15...Engaging portion, 17...Rubber plate, 18...
Groove, 22...clamp.

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, which form a chamber for concrete injection for forming a manhole, the inner frame has a plurality of A recess is provided, and a fitting body whose outer surface fits flush with the inner frame surface and is removable in a substantially vertical direction is provided in the recess, and the recess has the following features:
It has an inwardly extending side wall and a bottom wall, the side wall including:
An engaging part is formed to prevent the fitting body from escaping forward, and a rubber plate is laid on the bottom wall of the engaging part, and the base or arm part of the U-shaped step is placed on this rubber plate.
A groove is drilled into which only the lower half can fit, and a rubber plate is attached to the lower surface of the fitted body, and a groove is also formed on the lower surface of the rubber plate into which only the upper half of the base or arm of the U-shaped step can fit. A step embedding device for a manhole formwork, characterized in that the U-shaped step is held between the upper and lower grooves when the fitting body is fitted into the recess.