JPS64430Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field to which the invention belongs) The present invention relates to a drain paper guide device at the lower end of a mandrel that is provided with detection means for detecting objects to be detected attached to the drain paper at predetermined intervals. .

(Issues of the invention and its features) In order to facilitate the work of penetrating the drain paper into the mandrel, which is done prior to penetrating the drain paper into the ground, a gap was created in the internal space at the lower end of the mandrel for the drain paper to pass through. It has been considered to arrange two sets of a pair of guide plates arranged in the same plane at a distance from each other laterally.

On the other hand, a technique has already been developed by the present applicants to confirm the installation status of drain paper underground by detecting objects to be detected attached to drain paper at predetermined intervals using a detection means provided on a mandrel.
If an attempt is made to arrange the above-mentioned guide plate at the lower end of the mandrel provided with this detection means, the following problems arise.

The detection means for detecting the detected object attached to the drain paper is necessarily provided at a position close to the drain paper, but since the aforementioned guide plate is also arranged close to the drain paper, the position of both When the two objects approach each other, detection is obstructed by the metal guide plate.

The present invention has succeeded in overcoming this problem and disposing the above-mentioned guiding plate at the lower end of the mandrel in the prior art. In the internal space of the lower end of the mandrel, which is equipped with a detection means for detecting the object to be detected, two pairs of plates are arranged horizontally in the same plane with a gap for the drain paper to pass through. The plate extends from the lower end of the mandrel to an appropriate position above, and a notch of an appropriate size is provided in a portion of the plate near the detection means.

That is, in the present invention, the portion of the plate for guiding the drain paper close to the detection means is cut out to an appropriate size to prevent the presence of the plate from having an adverse effect on the function of the detection means. It goes without saying that it is desirable that this notch be as small as possible so long as its purpose is achieved.

(Explanation with Drawings) The figure shows the lower end of the mandrel 1, and 2 is a detection means installed in its internal space.

The detection means 2 is attached to the drain paper at predetermined intervals in advance when the mandrel 1 is pulled up to the ground while leaving it in the ground after penetrating the ground with the drain paper inserted into the mandrel 1. By detecting objects to be detected such as metal pieces,
It is used to confirm the underground installation state of the drain paper, and is installed near one side of the drain paper passing through the center of the mandrel 1.

3 is a plate constituting the guide device of the present invention;
There are two rows of a pair of plates 3, 3 lined up in the same plane, spaced apart horizontally so as to sandwich the detection means 2, and there is a gap 4 between each row of plates 3, 3 through which the drain paper passes. is provided.

Each plate 3 extends from the lower end of the mandrel 1 to an appropriate position above, and a notch 5 is formed in a portion close to the detection means 2 midway therebetween.

In addition, in the figure, 6 is a diagonal guiding notch provided at the upper end of the plate 3.

(Effects) Since the guide device of the present invention is composed of the plate body as described above, the drain paper can be guided smoothly and reliably at the lower end of the mandrel, increasing the efficiency of the work of inserting the drain paper into the mandrel. improves. Moreover, even if the plate is disposed close to the detection means, the function of the detection means is not hindered at all, so the practical effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the lower end of a mandrel according to the present invention, and FIG. 2 is a cross-sectional view taken along line A--A in FIG. 1. In the figure, 1... mandrel, 2... detection means, 3
... plate, 4 ... gap, 5 ... notch, ...

Claims (1)

[Scope of utility model registration request] In the internal space of the lower end of the mandrel, which is equipped with detection means for detecting objects to be detected attached to the drain paper at predetermined intervals, two of a pair of plates are arranged in the same plane with a gap for the drain paper to pass through. The plate body extends from the lower end of the mandrel to an appropriate position above the mandrel, and a cutout portion of an appropriate size is provided in a portion near the detection means in the middle of the plate body. Features a drain paper guide device at the lower end of the mandrel.