DE607283C - Thread chaser for the production of double-conical threads with two jointly controlled rows of cutting teeth lying next to each other in the same radial plane - Google Patents

Description

GERMAN EMPIRE

ISSUED ON DECEMBER 20, 1934

REICH PATENT OFFICE

PATENT LETTERING

CLASS 49e GROUP

Mannesmannröhren works in Düsseldorf

Rows of cutting teeth

Patented in the German Empire on May 28, 1931

So far, double-conical workpieces have been machined in such a way that the thread first cut into one cone, then spanned the workpiece and then created the thread in the other cone.

Since the reclamping is too time-consuming and therefore too expensive, you have to deal with different ones Tried way to thread in double-tapered workpieces in one Cut passage.

So one has z. B. Taps used with tools next to or behind one another, of which each tool has only one inclination and that, each one for itself, an additional radial movement, namely z. B. makes consecutive tools in the opposite direction. These The type of arrangement requires a certain clamping play of the tools, and from this there is a certain inaccuracy in the manufacture of the double-conical thread. Furthermore, a tool with two angularly adjoining one another is in the same Radial plane lying, jointly controlled rows of cutting teeth known. This tool however, it has the disadvantage that a perfect cut of the tool is very difficult to achieve. All normal cuts cause an incorrect change compared to the profile placed in the chaser the same, which is above all in an incorrect and for both halves of the cone has a particularly unequal flank angle. Another disadvantage is that that the last finishing cutting teeth of the first row of cutting teeth when cutting the thread of the second cone through the second row of cutting teeth on the tool act so that they become blunt and more or less unusable with the next cut are.

The disadvantages outlined are now avoided by a tool in which the two rows of cutting teeth, of which the first row of cutting teeth in the one cone and then the second row of cutting teeth in the other cone cuts the thread are a gap apart.

The drawing shows in

Fig. Ι schematically according to the invention crafted tool shown while

Fig. 2 shows the known design in which the cutting edges are adjacent.

In Fig. R, α is the double-conical body to be threaded; b is the tool; d and e are the two rows of cutting teeth, one of which is intended for a cone, as indicated by the tools shown in dashed lines,

the cutting teeth row d for the cone / and the cutting teeth row e for the cone «·. The tool travels in the direction of the arrow. Naturally, the teeth of both rows of cutting teeth d and e are at the same angle as the workpiece to be threaded.

The rows of cutting teeth d and e are through

separated by a gap h . The teeth

ίο Both rows of cutting teeth have a distance corresponding to the thread pitch. The gap h now initially gives the opportunity to regrind the rows of cutting teeth ά and e properly and easily on the chest in such a way that the profile is always uniform and precise with sufficient accuracy.

Another advantage, depending on the size of the gap, lies in the total or also partial protection of the first row of cutting teeth.

To ensure complete protection, the size of the gap depends on the cone slope and the to increasing depth of cut. In this case, with very small gradients, the result is pre-cutting a gap size that is determined by using the feed and speed commonly used in thread cutting causes a relatively large loss of time. To avoid the same, the thread cutting device of the relevant Machine designed so that the idle travel by high speed or is automatically bridged quickly by means of a fast feed.

In cases where the tapping device is not designed and you The first row of cutting teeth does not want to make the gap too large to save time only partially spared. But this is also an advantage. Added to this are the advantages of manufacturing and grinding.

The rows of cutting teeth d and e can be part of a one-piece tool. However, they can also be individual tools that are brought into the specific position by an intermediate piece k , but at the same time they are held firmly together with the intermediate piece k in some way.

When thread cutting, the tool is controlled in a known manner, z. B. by a Kejgel ruler.

The thread cutting tool can be used for both internal and external tapered Threads are needed.

The advantages of the described innovation lie in the fact that two of each other separate, but firmly connected rows of cutting teeth ensure greater accuracy, that also compared to other acquaintances a longer edge retention of the first row of cutting teeth and in general perfect grinding of the tool is achieved.

Claims (2)

Patent claims: 1. Thread chaser for the production of double-conical thread with two angularly side by side in the same radial plane, jointly controlled rows of cutting teeth, of which the first row of cutting teeth in one cone and then the second row of cutting teeth in the other cone cuts the thread, characterized in that the two rows of cutting teeth (d and e) are separated from each other by a gap (Ji) \ '. 2. Thread chaser according to claim 1, characterized in that the two rows of cutting teeth (d and e) with an intermediate piece (k) are either in one piece or consist of several parts. 1 sheet of drawings