JPH028077Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a step that is fixed to the mass of the side wall of a manhole entrance, and its purpose is to install the step safely, reliably, and firmly, and to improve its appearance and workability. This invention relates to a manhole step mounting structure.

Conventionally, steps have been fixed to this type of manhole to allow workers to enter and exit, but conventional steps have two methods: one is to embed them integrally when the manhole is formed, and the other is to pierce the manhole wall after forming. There was a way to install the steps later into the holes.

First of all, with the former method, there is no problem in terms of safety, but the formwork where the steps are attached is fine and it takes a lot of time to assemble, and the joints of the formwork cause vibration when compacting the concrete. This makes it easy for molded products to become misaligned, and the skin of the molded product will show tromole and marks of misalignment at the joints of the molds, resulting in a very poor appearance.

The latter is a method designed to solve the appearance and workability of the former, but in this method, the hole penetrated through the manhole wall is made larger than the diameter of the step.
Insert the step into the hole, tighten it with bolts and nuts from the outside of the manhole, and fill the tightened part with mortar from the outside to attach it. With this method, the hole drilled through the manhole is larger than the diameter of the step, so the step tends to wobble, and the outer mortar may crack, causing water to leak from the outside of the manhole to the inside, and from the inside to the outside. In time, harmful acidification will occur and there is a risk of extraction due to corrosion of the steps.

As described above, both methods were unsatisfactory in terms of safety, reliability, strength, appearance, and workability.

The present invention was devised to solve the above-mentioned drawbacks of the conventional structure, and a guide steel pipe with a retaining plate etc. fixed to it is buried in the step installation position of the manhole side wall block. A manhole that ensures safety by inserting a mounting part with a step engagement part into a steel pipe and fixing it with mortar or milk cement, and by engaging a guide steel pipe retaining plate to the step engagement part. This provides a step mounting structure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of manholes 1 and 2 according to the present invention, and 3 is a step. In step 3, as shown in Fig. 3, an engagement part 4a with a ring-shaped groove is formed on the attachment part side of the U-shaped steel material 4, and the parts other than this attachment part are made of polypropylene or the like. The step portion 4b is coated with resin.

On the other hand, in the manhole side wall blocks of the manholes 1 and 2, a guide steel pipe 6 is embedded with a retaining plate 5 fixed thereto as shown in FIGS. 4A and 4B at the mounting position of the step 3. The guide steel pipe 6 is formed to have a larger diameter than the mounting portion of the step 3, and the bottom plate 6a is formed to be larger than the guide steel pipe 6. Further, the retaining plate 5 is formed of spring steel or the like, is inserted into the inner side of the groove formed in the side wall of the guide steel pipe 6, and has its base end welded to the outside of the guide steel pipe 6. The tip is narrowed in an eight-shape shape within the guide steel pipe 6 so that the engaging portion 4a of the step 3 engages with it.

FIG. 5 is a cross-sectional view of the main part showing the installation structure of the step 3 according to the present invention, in which the guide steel pipe 6 is integrally buried in the manhole side wall block in advance, and then the step 3 is installed with mortar or milk-based cement. Insert the attachment part of and attach the retaining plate 5 to the engagement part 4a.
The caulking material 7 is embedded in the inlet portion.

As explained in detail above, the step mounting structure according to the present invention is such that the ring-shaped grooved engagement part formed on the step mounting part is inserted into the guide steel pipe with a retaining plate embedded in the manhole side wall block. The step is inserted and fixed with mortar or milk cement, ensuring reliable and strong fixation. Therefore, even if a crack occurs, there is no fear that the step will come off, and safety can be ensured, which provides practical effects.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of the manhole according to the present invention, Figure 3 is a top view of the step according to the present invention, and Figures 4 A and B are top views of the guide steel pipe to which the retaining plate according to the present invention is fixed. FIG. 5 is an enlarged sectional view of essential parts showing the step mounting structure according to the present invention. 1, 2...manhole, 3...step, 4...
Steel material, 4a... Engaging part, 4b... Step part, 5... Retaining plate, 6... Guide steel pipe, 6a... Bottom plate, 7
...Caulking material.

Claims (1)

[Scope of utility model registration request] forming an engagement part with a ring-shaped groove at the end of the U-shaped steel member on the mounting part side of the manhole step, burying a guide steel pipe at the step mounting position in the wall mass on the entrance side of the manhole; The proximal end of a slip-off prevention plate whose distal end becomes narrow in a figure-eight shape within the guide steel tube and engages with the engagement portion is fixed near the entrance of the guide steel tube, and the engagement portion of the step is secured to prevent the slip-out of the guide steel tube. A manhole step mounting structure characterized by engaging a stop plate.