JPS6377607A - Tool for male thread cutting - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to metalworking technology, and more particularly to die-type external thread cutting tools.

Within one and the same nominal thread diameter and pitch, the thread parameters depend on the tolerance and fit or the application of the threaded joint (e.g. threads for high or low temperature operation, threads to be electroplated, etc.). It's different.

It is known that each such thread is usually cut by a separate thread cutting tool or by a complex thread cutting head provided with means for precise readjustment.

Readjustment to a wide range of thread diameters is only possible with overly complex thread cutting heads.

Furthermore, it is known that a double bift screw with variable screw turn thickness and variable lead screw diameter ensures an even distribution of the load between the screw turns. Such threads can be cut using complex manufacturing techniques, for example by machining each side of the thread profile separately.

Thread-cutting dies are known in the art, which are provided with a groove on the end face and have a thread chaser, the groove on one end face being offset by half the angular pitch with respect to the groove on the other end face (e.g. Certificate No. 645.784 International Classification 823G
5104. Published in 1979). This type of die is machined with a continuous zigzag threaded ring,
This ring has a tendency to become wedged in, pushed into, caught on, or caught in the workpiece being processed.

With this technology, the Soviet Union Inventor's Certificate No. 1 released in 1966
Thread cutting dies such as those described in International Classification No. 99,644 823G5104 are also known. The end face of the die has a groove with a straight front face forming a cutting edge at the intersection with the central threaded hole.

However, this type of die is inherently disadvantageous due to the complexity associated with chip removal, the integral connection of the geometrical parameters, and the constructional difficulties due to the fact that the grooves can only be produced by milling.

Such a die (or group of such dies) cannot guarantee readjustment for cutting threads of different diameters or for different applications. Furthermore, this type of die does not evenly distribute the load between the thread turns of the threaded joint and does not solve other problems associated with the desire to extend thread cutting capacity.

SUMMARY OF THE INVENTION The object of the present invention is to provide a round die-type external thread cutting tool that is constructed to ensure easy manufacture, provide more favorable thread cutting conditions, and widen the range of uses of the tool.

The gist of the present invention is a round die-shaped external thread cutting tool having a housing with an end thread chaser, in which the thread chaser extends toward the interior of the housing, the housing is formed into an annular body, and The inner diameter of the annular body is greater than the diameter of the threaded blade of the threaded chaser by the height of the threaded chaser.

This structural arrangement of the proposed tool provides good cutting conditions by facilitating chip removal and disposal. Another advantage is that by overcoming the traditional constraints imposed by dimensional interrelationships, the above-mentioned distribution allows for optimal thread cutting conditions such as tool geometry (thickness of the die driver, number of die cutters, etc.). width, etc.), thereby making the tool itself more concise.

Preferably, the screw chaser has the shape of arcuate elements with a thickness not exceeding the thickness of the housing, these arcuate elements being cantilevered to the end face of the housing by their parts, and The outer and inner surfaces meet the outer and inner surfaces of the housing, respectively, while the portion of the screw chaser extending towards the interior of the housing is defined by at least the end of each arcuate element.

Since the structure of such a screw chaser is easy to realize, the housing and die chaser can be formed by using powder metallurgy or by plastic deformation of a tubular workpiece.

In contrast to the above, the screw chaser is shaped as a sector element.

This simplifies the manufacture of the tool and allows the housing and die chaser to be formed by stamping sheet steel workpieces.

Preferably, the tool is provided with additional thread chasers interposed between the main thread chasers, the end faces of these additional thread chasers substantially corresponding to the end faces of the housing.

The screw chasers are divided into groups such that preferably one group of chasers is interposed between another group of chasers and are offset from each other in the axial direction of the housing.

This allows improved cutting conditions by distributing functions between chasers that are differently offset relative to the tool housing.

Unlike the above, one group of chasers has thread cutting blades while the other group of chasers has calibrated thread blades.

This ensures optimal geometrical parameters (for example rake angle) of the tool elements, which parameters are most favorable for the die group performing its function.

The thread cutting blade has a full profile variable pitch,
The thread pinch can also be increased at the beginning of the thread turn of the threaded blade and tapered down to the nominal pitch at the final thread turn of the threaded blade.

This allows threading to be performed according to the manufacturing procedure.

In contrast to the above, different groups of screw chasers can also be arranged at both ends of the housing.

This improves the conditions for centering the tool on the workpiece to be machined.

Preferably, the proposed tool is provided with at least one additional annular housing arranged concentrically with the main housing, the additional housing having end thread chasers arranged between the thread chasers of the main housing. and has a threaded blade diameter substantially equal to a threaded blade diameter of the main housing.

This provides new thread-cutting capabilities by allowing threads to be cut by chasers fixed to different housings.

Unlike above, the additional annular housing has an outer diameter that is substantially equal to the inner diameter of the main housing, and the additional housing is received concentrically within the main housing.

Such an arrangement makes it possible to design a tool in which one of the housings is accommodated inside another housing, with the thread cutter being carried alternately in these housings.

Preferably, the main housing and the additional housing are axially and angularly settable displaceable relative to each other.

This allows threads with different mating and designations to be cut with the same tool by displacing the housing angularly and axially.

In contrast to the above, the main housing and the additional housing are interconnected by flexible elements.

This improves the dimensional stability of the tool by automatically maintaining the desired pitch diameter.

Preferably, the main housing and the additional housing of the proposed tool are axially displaceable with respect to each other, and the screw blades of the screw chasers of the main housing and the additional housing have different pitches.

Such a distribution provides a double-pinch screw with variable spacing, which can more evenly distribute the loads applied over the screw turns of the threaded joint.

In contrast to the above, the proposed tool is provided with at least two additional annular housings which can be inserted further into the main housing, one within the other so as to be able to rotate with respect to each other, these housings having the inner surface of each of the housings is placed eccentrically with respect to the outer surface of the
The number of thread chasers is equal to the number of housings, each housing having one such thread chaser, and all thread blades of all screw chasers are arranged on one helical line.

The above arrangement ensures readjustment of the tool to cut threads of different diameters.

Preferably, in the proposed thread cutting tool, the thread blades of the thread chasers of the main housing and the additional housing have the following formula S = P (n 10%), where S is the magnitude of the axial deviation and P is the thread pinch , n is the number of screw turns required for automatic tool tightening).

This feature of the tool according to the invention ensures that a cylindrical surface is obtained by cutting a thread turn cut by a chaser mounted on the main housing and a thread turn cut by a chaser fixed on the additional housing. do.

Referring now to FIG. 1 of the accompanying drawings, there is shown an external thread cutting tool embodying the invention in the form of a round thread cutting die with a radial thread chaser. The tool according to the present invention consists of a housing 1 having an annular shape and a screw chaser 2 arranged on an end face of the housing 1 and offset with respect to the housing 1. The thread diameter of the chaser 2 is smaller than the inner diameter of the annular housing 1 by the height of the chaser 2.

The screw chaser 2 has an arcuate element whose thickness does not exceed the thickness of the housing. The chaser 2 is cantilevered to the end face of the housing by a portion 3 having inner and outer surfaces corresponding to the inner and outer cylindrical surfaces of the housing 1, respectively.

Tools embodying the invention are manufactured with geometrical parameters determined solely by the most favorable cutting conditions, thus eliminating the traditional limitations imposed by the interdependent dimensions of conventional thread cutting dies. There is. As a result, the number, height, width, and arrangement of the thread chasers, as well as the inner and outer diameters of the housing, are selected from a purely structural point of view, independent of the threads to be cut. These advantages provide new design capabilities that are discussed in detail below.

When threading with such a tool, favorable conditions for chip removal are ensured by the fact that the thread chaser projects into the interior of the tool housing, thereby creating a cavity for accommodating the chips. Also, the number of chesas,
Since the width, height and position can be selected arbitrarily, thread cutting conditions are also optimized.

With reference to FIG. 2, an improved version of the proposed thread cutting tool is characterized by a tangential arrangement of the chaser with respect to the workpiece to be machined. The threaded blade 4 of the chaser 2 in this tool is provided on the inner side of the chaser 2, and the width of the screw chaser 2 is substantially equal to the width of the cylindrical land designated by number 5 in FIG. equal. The tangential arrangement of the chaser 2 provides rigidity to the chaser 2.

The tools described with reference to FIGS. 1 and 2 can be manufactured from tubular workpieces by using stamping or powder metallurgy techniques.

Next, referring to FIG. 3, the screw chasers 6 and 7 are
A chaser 6 is interposed between chasers 7 and is configured as a sector element offset in the axial direction with respect to the chasers 7.

4 and 5 show a modification of the thread cutting tool, in which the chaser 6 is axially displaced relative to the housing,
It is arranged between other chasers 8, and the end face of the housing 8 is formed at the same height as the end face of the housing 1.

Grouping of screw chasers is done by varying both the size and the direction of axial displacement. Groups of such chasers can have different functions in the proposed tool. For example, referring to the tool shown in FIG. 4, chaser 6 houses a cutting screw blade, while chaser 8 is provided with a calibrating screw blade.

To optimize the cutting conditions, the geometrical parameters of the cutting blade and the calibration screw blade must be different, so that the cutting blade 6 has a more pronounced rake angle and smaller serrations than the calibration blade 8. Referring to FIG. 6, the chaser 6 has a full profile variable pitch threaded blade 9, with a large pitch (P+Δ'') in the front threading turns tapering to a nominal pinch value P in the back threading turns.

For comparison, FIG. 6 also shows the nominal thread profile 10 of the thread cutting blade. Since the length of the contact line between the thread cutting tool and the workpiece is determined by the distance between the chaser groups that are most axially offset from each other, the centering of the thread cutting tool on the workpiece is determined by the magnitude and direction of such offset. You can control the degree of

During thread cutting, the tool exhibits the degree of centering required for the predetermined shape of the workpiece being machined.

Assuming that the longitudinal axis of the workpiece is straight, the groups of screw chasers are offset to either side of the ends of the tool housing so that the tool tends to center more easily. The thread cutting blade removes most of the thread metal, while the calibrating blade operates to protect and calibrate the thread. Thread cutting and calibration blade parameters designed to perform different functions provide optimal conditions for forming threads on the workpiece.

Full profile thread cutting blade with variable pinch thread cutting edges can cut threads according to production procedures. This reduces the lip angle φ, but distributes the intersections between a large number of threads without significantly increasing the amount of friction between the workpiece and the tool.

The tools shown in Figures 3.4.5 and 6 can be manufactured by stamping sheet steel.

The geometry of the housing present in the diameter of the threaded blade (in particular the inner and outer diameters of the housing) makes it possible to provide the proposed tool with several housings, one of which is arranged concentrically inside the other. .Each of the housings accommodates a dedicated chaser of the same thread diameter. Chasers placed on separate housings occupy spaces between chasers of the main housing.

FIG. 7 shows two improved examples of the proposed tool, both of which are substantially the same as the tool shown in FIG. The main annular housing 11 has an inner diameter equal to the outer diameter of the further annular housing 12. 8.9 and 10
The figure shows another annular housing placed within the main annular housing 11 and a chaser 13 fixed to this additional housing.
The tool is shown assembled into an integral tool by placing the die between chasers 14 of the main housing.

The outer surface of the additional housing 12 has an annular groove 15 (FIGS. 7 and 10) of trapezoidal or triangular cross section, whereas the main housing 11 is provided with threaded holes 16 axially offset from each other. , Therefore, the screws 17 (FIG. 10) that engage with these holes 16 are inserted into the grooves 15 by the tapers 18.
is touching the other side of the

During the manufacture of the tool, the additional housing 12 is attached to the main housing 1.
1 and then the tool is screwed onto a male gauge or master screw corresponding to the screw to be manufactured. By rotating the additional housing 12 and displacing it axially relative to the main housing 11, the tool can be adjusted to the screw to be produced by means of the screw 17, after which the mutual position of the housings is locked by means of the screw 17.

Since the groove 15 is annular and the tapered portion 18 of the screw 17 contacts the other side of the groove 15, the additional housing 1
2 can take any axial position, and the chaser 1
Main housing 11 even to the point where 4 and Chaser 13 come into contact.
It can be rotated at any angle.

Therefore, in practice, a certain misalignment may occur in the geometrical positions of the screw blades of chasers 14 and 13.

When cutting threads with this tool, due to misalignment of the thread blades during adjustment of the tool, the chaser fixed to one housing will act to undercut the thread profile formed by the chaser fixed to the other housing. Therefore, the pitch diameter of the thread during processing can be adjusted. Since one chaser is arranged between the chasers of the other housing, the chasers operate in parallel, thereby preventing insufficient threading or the formation of incorrectly threaded sections. When switching to manufacturing screws with other tolerances and d-fits, or when the blades are worn, readjust the tool as described above.

Another variant of the proposed tool is possible, as shown in FIGS. 11 and 12, in which automatic readjustment is possible after the blade is worn.

The tool is further provided with a ring member 19 which is arranged between the main housing 11 and the additional housing 12.

The outer surface of the ring member 19 is provided with an annular groove, and the ring member 19 is connected to the additional housing 12 by a sliding key (not shown). The additional housing 12 has a groove 20 (a first
1) and threaded holes 22 of the main housing 11 are provided with screws 21 passing through these holes 20 to engage them. The head of the screw 21 is in contact with the disc spring 23.

To adjust the tool, it is necessary to loosen the screw 17, and by rotating the housing 12 relative to the housing 11, the tool is adjusted to the desired thread diameter using the male gauge. After this, screw 17 is tightened to lock the relative angular position of housings 11 and 12. Rotating the screw 21 compresses the spring to a predetermined force that reacts to the axial displacement of the additional housing 12 relative to the main housing 11.

When threading with this tool after the thread cutting blade has worn out, an axial cutting force is generated and the housing is moved axially relative to the housing 11 overcoming the resistance force of the disc spring 23. This result Chaser 1
The misalignment of the thread blades 3 and 14 becomes more pronounced, and the thread profile cutting becomes wider than that of the thread profile cutting 18, and the pitch diameter is reduced to a predetermined value.

The off-centering of the threaded blade makes it possible to control the pitch diameter within the desired nominal value. This advantage allows such a tool to cut threads with different fittings and different names, resulting in a smaller thread cutting tool and more efficient tool operation. The ability to reduce the pitch diameter of the thread that is cut after the chaser blade wears out improves the dimensional stability of the tool.

The improved tool according to the invention shown in FIGS. 13 and 14 includes a main housing 11 and an additional housing 1.
2 is a sliding key 24 that does not rotate (can be relatively displaced in the axial direction).The chaser of the main housing 11 (Fig. 13)
The thread pitch at is different from the thread pitch of the chaser of the additional housing 12 and is related to the latter pitch by the following formula:

c+g α p, = 2P-P.

Here, P is the pinch of the thread to be cut, Pl is the thread pitch of the main housing chaser, and P2 is:
Thread pinch of the chaser of the additional housing, ω is the half-taper angle of the main diameter of the thread to be cut, α is the thread profile angle of the screw chaser.

When thread cutting is performed with such a tool, the axial movement speeds of the main housing chaser 12 and the additional housing chaser 13 differ due to the difference in the thread pitch of the chaser blades.

Therefore, the thread 25 (first
In FIG. 5), the chaser 13 cutting the thread 26 cuts the side surface of the profile on the side surface of the thread. Since the allowance removed varies continuously, the screw 27 has a variable main diameter.
(shown by hatching in FIG. 15) is formed. One side of the resulting thread 27 is cut by a chaser with a thread pitch that is substantially different from the pitch of the chaser cutting the other side of the thread profile.

The resulting direction of change (increase/decrease direction) of the screw scraping is determined by the initial axial set value of the chaser 12 relative to the chaser 13, and is determined by the Taber angle (angle ω) of the screw scraping.
is determined by the relationship between the thread pitches of chasers 12 and 13.

Such a tool makes it possible to obtain double pinch screws with variable main diameter and variable thread turn thickness without using special tools or readjusting the equipment in use. Cutting screws of this type, such as bolts, after fitting them into a conventional nut, ensures a threaded joint with an even load distribution between the thread turns.

Referring now to FIGS. 16 and 17, these figures include the main housing 11 and the additional housing 12, as well as the second additional housing 28. Each of the housings carries one end chaser. The main housing 11 carries a chaser 29 , the first additional housing 28 carries a chaser 30 , and the second additional housing 28 carries a chaser 31 . The tool is provided with a shell 32, the inner surface of which, the main housing 11, and the additional housings 12 and 28 are offset by a predetermined amount with respect to their outer surfaces. The second additional housing 28 occupies space within the additional housing 12 , which is fixed within the main housing 11 , which in turn is housed within the shell 32 .

The attached drawing shows the separate elements of the tool.

18 shows the shell 32, FIG. 19 shows the main housing 11 with the thread chaser 29, FIG. 20 shows the additional housing 12 with the chaser 30, and FIG. 21 shows the screw chaser 31. Second additional housing 28 is shown, shell 32 and housings 11.12 and 2
8 are formed with splits 33, 34, 35 and 36, while the outer surface of shell 32 is provided with holes 37 for receiving clamp screws (not shown) of the die stock.

The tool is adjusted to produce the desired diameter thread with a male gauge or master screw using a device that properly centers the gauge relative to the outer surface of shell 32. Since the inner surface of the shell and each of the housing are eccentric with respect to their outer surfaces, rotating the housing changes the radial position of the chaser, thereby adjusting the produced screw to the desired diameter. After adjusting the blades of chasers 29, 30 and 31 to the gauge screws and making them equiangularly spaced, insert the die driver screw into hole 3.
7. Together with this, the slots 33, 34, 35 and 36 compress the shell and housing and lock them together.

Threads are cut with such tools in substantially the same manner as threads are cut with conventional tools.

The use of the proposed tool offers substantial economic advantages due to the cylindrical structure and ease of manufacture. The tool does not have complex contoured surfaces; both the inner and outer surfaces of all housings are cylindrical and can be amenable to machining with conventional general-purpose equipment. The thread cutting die and the eccentric surface of the housing form one unit which eliminates the need for a kinematic link between the eccentric point and the thread cutting element.

Another advantage of the proposed tool is that it can be readjusted to cut a wide range of thread diameters while maintaining a simple construction.

FIGS. 22 and 23 show an improved tool consisting of a main housing 11 with a group of thread cutting chasers 14 and an additional housing 12 with a group of chasers 13 as described above.

The thread cutting blades in chasers 13 and 14 have equal pitch. The profile of the blades is trapezoidal, but their internal diameter is equal to the pinch diameter of the corresponding triangular screw, and the additional housing 12 is internally connected to the main housing 1.
Accommodates 1. The relative axial positions of these housings are permanently locked by screws 38 so that the chasers of one group are moved axially relative to the blades of the chasers of the second group by a distance determined from the equation: It shifts.

S=P (n+’/z) Here P is the thread pitch n is the number of screw turns required for automatic tightening.

During operation of such a tool, the chasers of the first group form a thread that ensures tool feeding with automatic tightening. Not only do the trapezoidal blades of the two groups of chasers overlap in the spaces between the screw turns when the axial portions are aligned, but the crests or cutting edges of the threads of the second group of chasers of such an arrangement are similar to those of the first group. occupies a helical line with the root of the thread of the chasers, so the second group of chasers attempts to remove the thread cutting by the first group of chasers and form a smooth cylindrical surface. The lack of thread cutting with such tools is determined by the number of screw turns required for automatic tightening. Rotating the tool in the opposite direction removes the tool from the machined surface. Along with this, if one group of chasers scratches the surface, a second group of chasers will remove these scratches. If the rear rack angle of the chaser is negative, the risk of surface seeding is eliminated.

Other improvements of the proposed tool to prevent surface cutting are also possible. For this purpose, the chaser must have a thread of one pitch with a different number of starts.

The proposed tool for cutting external threads has the following advantages:

It can be machined by equipment without a feeding mechanism and by automatic equipment that automatically tightens tools.

Ability to machine non-rigid workpieces that deform when machined with a direct rotating thread cutting tool. The quality of the workpiece surface is improved because it is machined with a multi-blade tool. The ability to machine workpieces with curved axes since the tool is centered according to the surface being machined.

Easy adjustment of multi-station automatic equipment since machining and thread cutting are carried out under the same cutting conditions.

Able to be lathe-processed using an automatic centering tool fixed to a floating chuck.

The main advantage of the proposed threading tool is that the workpiece clamped in a vise can be machined by hand. At present, bench tools for turning lathes are not available.

In view of the above, all the structural improvements of the proposed thread cutting tool are characterized by its cleanliness and ease of manufacture. These tools can be manufactured from pipe or sheet workpieces by stamping.

The thread cutting process can be optimized by means of separate axial displacement of the thread chaser relative to the tool housing. This can be achieved by dividing the different functions of the chaser groups and optimizing the geometry of the chasers in each group to perform separate functions. More particularly, this functional division principle is utilized when the chaser of one die has a thread cutting blade while the other chaser has a calibration blade.

Because the thread of the thread cutting blade has a full-profile variable pinch, the axial offset of the chaser group is varied, allowing control of the degree of tool alignment on the workpiece while still allowing the chaser to be controlled. By providing some thread cutting blades, threads can be cut according to the thread manufacturing process.

The capacity of the end chaser to be radially offset relative to the cylindrical housing is such that the tool chaser can be accommodated in a separate housing located within the other, thus providing unprecedented thread cutting capacity.

This design principle allows for the production of double-pitch threads with variable main diameters and threads with a wide range of pitch diameters, as well as tools that can be readjusted to produce threads intended for different mating and operating conditions. It is unique in that it is a tool that can be readjusted.

New capabilities are also available to utilize the proposed thread cutting tool for non-threaded profile forming with automatic tool tightening, in particular to obtain smooth cylindrical surfaces.

[Brief explanation of the drawing]

FIG. 1 is an axonometric projection view of the male thread cutting tool according to the present invention;
FIG. 2 shows an external thread-cutting tool with tangentially arranged chasers, FIG. 3 shows a thread-cutting tool with a chaser in the form of a sector element, and FIG. 4 shows an additional chaser with an end face corresponding to the end face of the housing. 5th sectional side view of the tool
Figure 4 is a top plan view of the tool shown in Figure 4; Figure 6 is a cross-sectional view of the full profile variable pitch thread cutting blade;
8 shows the tool shown in FIG. 7 in assembled condition; FIG. 8 shows the tool shown in FIG. 7 in assembled condition;
FIG. 9 is a top plan view of a thread cutting tool that can adjustably displace the additional housing in the angular and axial directions with respect to the main housing, FIG. 10 is a sectional view taken along the line X-X in FIG. 9, and FIG. The figure shows a top plan view of a modification of the tool in which the main housing and the additional housing are connected via a flexible element, FIG. 12 is a sectional view taken along the line XII-XII in FIG. 11, and FIG. 13 14 is a side view of the tool shown in FIG. 13, and FIG. 15 shows a double pitch screw with variable spacing. Figure 16 is a top plan view of a tool that can be readjusted to cut threads of variable diameter;
Figure 17 is a side sectional view of the tool shown in Figure 16;
19 is a view of the main housing of the tool shown in FIG. 16; FIG. 20 is a view of the additional housing of the tool shown in FIG. 16; FIG. Figure 16 is a view of the second additional housing of the tool shown in Figure 16;
2 is a side sectional view of a tool for forming a cylindrical surface, and FIG. 23 is a top view of the tool shown in FIG. 22. Listed with reference numbers: housing, 2... screw chaser, 3...
Part of thread chaser, 4... Thread cutting blade, 5... Cylindrical land, 6.7... Chaser, 8... Additional chaser, 9.10... Thread blade, 11... Main Housing, 12... Additional housing, 13.14... Thread chaser, 15... Annular groove, 16... Hole, 17... Thread, 18... Thread taper, 19... Ring member , 20... Groove, 21... Screw, 22... Hole, 23... Spring, 24... Key, 25.26
．． 27... Screw, 28... Additional housing, 29.30.31... Chaser, 32... Shell, 33.34, 35.36... Split, 37...
Hole, 38...screw.

Claims (15)

[Claims] (1) Housing (1) with end thread chaser (2)
), the thread chaser (2) extends toward the inside of the housing (1), the housing (1) is formed in the shape of an annular body, and the inner diameter of this annular body is the diameter of the thread. A male thread cutting tool characterized in that the height of the chaser (2) is larger than the diameter of the thread plate of the chaser (2). (2) The screw chasers (2) have the shape of arcuate elements with a thickness not exceeding the thickness of the housing (1), and these arcuate elements are cantilevered by their portions (3) into the housing. (1), the outer and inner surfaces of these parts coincide with the outer and inner surfaces of the housing (1), respectively, while the part of the screw chaser (2) extends towards the interior of the housing (1). 2. A tool according to claim 1, characterized in that is formed by at least an end of each arcuate element. 3. Tool according to claim 1, characterized in that the screw chaser (6) is designed as a sector element. (4) A patent characterized in that additional thread chasers (8) are provided interposed between the main thread chasers (6), and the end faces of these additional thread chasers substantially coincide with the end faces of the housing (1). A tool according to claim 1 or 3. (5) The screw chasers (6, 7) are divided into groups such that one group of chasers (6) is interposed between another group of chasers (7) and are offset from each other in the axial direction of the housing (1). Claim 1 characterized in that
The tool according to any one of items 1 to 3. (6) Tool according to claim 4 or 5, characterized in that one group of chasers (6) has thread cutting blades, while the other group of chasers (8) have calibrating screw blades. (7) The thread cutting blade (9) is of full profile variable pitch, the thread pitch being large at the beginning of the thread turn of the thread blade and tapering down to the nominal pitch at the last turn of the thread blade. Range 6th
Tools listed in section. (8) A tool according to claim 5, characterized in that different groups of screw chasers (6, 7) are arranged at both ends of the housing (1). (9) there is provided at least one additional annular housing (12) arranged concentrically with the main housing, the additional housing (12) having an end located between the screw chasers (14) of the main housing (11); Part screw chaser (13
) and having a diameter of the threaded blade substantially equal to the diameter of the threaded blade of the main housing. (10) The additional annular housing (12) is the main housing (
11) The tool according to claim 9, characterized in that the additional housing (12) is housed concentrically within the main housing (11) and has an outer diameter substantially equal to the inner diameter of the main housing (11). . 11. Tool according to claim 10, characterized in that the main and additional housings (11, 12) are capable of axially and angularly settable displacements relative to each other. 12. Tool according to claim 10, characterized in that the main and additional housings (11, 12) are interconnected via flexible elements. (13) The main and additional housings (11, 12) are axially displaceable with respect to each other;
11. The tool according to claim 10, wherein the screw blades of the screw chasers 1 and 12) have different pitches. (14) At least two additional annular housings (12, 28) are provided which can be inserted into the main housing (11) one within the other for mutual rotation, these housings (11, 12, 28 ) are arranged so that the inner surfaces of each of the screw chasers (29, 30, 31
) is equal to the number of housings (11, 12, 28), each housing (11, 12, 28) having one such thread chaser and all thread chasers (29, 30
, 31) are arranged on one helical line. (15) The thread blades of the thread chasers (14, 13) of the main and additional housings (11, 12) are determined by the following formula S=P
(n + (1/2)) (where S is the size of the deviation in the axial direction, P is the screw pitch, and n is the number of screw turns required for automatic tool tightening). The tool according to any one of claims 1 to 10, characterized in that the tool is offset.