CS215451B1 - Method of making the holes in the jump of the wall of helical corrugated drain pipe - Google Patents

Description

SUMMARY OF THE INVENTION The present invention provides a method for making holes in the nipple protrusions of a wall of a helical corrugated plastic drainage tube located in a valley of wool (hereinafter referred to as tubes) and a device for carrying out this method - a cutting head provided with knives. to the bottom of the wave valley. The present invention is linked to the author's certificate No. 157 579.

In the prior art devices, each knife carries out one simple cut and the overall cut-out of the nipple protrusions is achieved by composing two diverted cuts. By means of this device, infiltration apertures of lenticular shape are produced, which is disadvantageous with respect to the shape of soil grains. Another disadvantage of this device is its high sensitivity to the geometric accuracy and the strength of the pipe. As a result, some of the holes created by the nipple protrusion through the device are larger, while others are smaller or even not cut at all.

Another known method of making holes is that the holes are finished in several rows so that the blades are mounted on a rigid holder inside the pipe and, as the pipe moves through the blades, "ruptures" the holes in the walls of the pipe helix. The disadvantage of this method is the weakening of the thread support profile and hence the lower radial pressure strength of the pipe, which is a basic requirement for drainage pipes.

Prior to the preparation of this application, the genesis files were studied:

NSR 1203940 - Method and apparatus for the manufacture of drainage pipes

Disclosure document NSR 1459414 - Method and apparatus for the manufacture of drainage pipes

Cs. U.S. Pat. 168 568 - Equipment for the manufacture of plastic pipes

The method and apparatus of the present invention eliminate the above drawbacks by providing three cutting blades on each of the cutting heads (equal to the number of threads of the tube) that are symmetrical about the intended helical surface passing through the center of the wave valley. The holders are radially adjustable by an adjusting screw and locked in position by a locking screw. Each pair of blades has one pair of thin blades arranged on the holder so; that the distance between their cutting edges is equal to the desired width of the infiltration opening being produced. This pair performs two smooth parallel cuts in the nipple ridges in the wave valley of the tube, which are simultaneously parallel to the imaginary helical surface passing through the center of the wave valley. The overall nipple cut-out is achieved by means of a third knife, which is placed on a common holder behind a pair of thin knives (in terms of head rotation) and punctures a portion cut by them. The holes thus produced have a desirable regular rectangular shape and their edges are smooth. The blades are simple in shape and cheap to manufacture. Adjusting the knife holders in the radial direction and securing them in the set position allows the blades to be adjusted to the correct distance from the bottom of the pipe according to possible manufacturing deviations of the pipe diameter. The actual embodiment of the invention is set forth in the following description and in the accompanying drawing.

Fig. 1 is a front view of a cutting head with knife holders. Fig. 2 is a vertical section taken through the knife holder and the axis of rotation of the knife hlaw.

Exemplary embodiment

In the center of the cutting head 1, a drainage tube 3 with nipple protrusions 5 extends in the axial direction in a valley of helical waves. On the cutting head 1, the carriers with the adjusting screw 10 are fastened by axial bolts 6 and pins 7. On each of the carriers 8, a holder 9 is fixed, which by means of the adjusting screw 10 is radially displaceable and locked in position by a locking screw 11. 2 cutting blades 12 and a stabbing knife 13, which is located behind the pair of blades 12 in the direction of rotation of the cutting head, are fastened to the grooves. The adjusted position of the blades 12 and 13 is secured by the screw 14.

By rotating the cutting head 1, the drainage tube 3 is advanced by means of centering rollers 2 with an exhaust collar 4 in the axial direction through the cutting head 1. The blades 12 and 13 are adjusted on the holder 9 so that they do not completely reach the bottom of the valley of the drainage tube 3 and cut the tops of the projections 5, whereby rectangular water inlet openings are formed in the wall of the drainage tube 3. Possible manufacturing deviations of the drainage pipe diameter are compensated by the radial adjustment of the knife holders

Claims (3)

SUBJECT 1. A method of making holes in the nipple protrusions of a helical corrugated plastic drainage pipe characterized in that the peaks of the protrusions in the valley of the drainage tube are cut by rotating the blades around the punched tube axis so that the protrusions are first two cuts - passing through the center of the valley of the wave - cut and further cut, the cut apex of the protrusion is punctured, the apertures thus made having a rectangular shape at a perpendicular diameter to the plane intersected by the axis of the tube. 2. Apparatus for making holes in accordance with BACKGROUND OF THE INVENTION according to claim 1, characterized in that 1 to 5 holders (9) are disposed on the cutting head body (1) and on each of them are arranged blades (12) such that the blades are spaced apart by the desired width of the infiltration hole a cutting knife (13) which is located behind the blades (12) in the direction of rotation of the cutting head, the surfaces of the holder (9) on which the blades (12) and (13) are clamped with an angle equal to the plane perpendicular to the tube axis (3) angle of helix tube. Device according to claim 2, characterized in that the number of holders (9) is equal to the number of threads of the helical corrugated pipe (3).