External thread repairing tool

Abstract

The invention relates to a device for repairing an external thread. A thread repair tool (1) comprises a first tool body (2), a second tool body (3) and rollers (4, 6) mounted on the tool bodies (2, 3), respectively. The first tool body (2) and the second tool body (3) are movably connected to each other at their first ends (2.1, 3.1), each of said tool bodies (2, 3) having an arcuate shape so as to form an annular shape when the thread repair tool (1) is in a closed state. The technical result of the invention is that the external thread is repaired and prevented from being cut while maintaining the diameter of the external thread at a desired value during the reshaping of the thread material.

Description

Technical Field

[0001] The invention relates to a device for repairing external threads. Background Art

[0002] It is known that repairing external or outer threads (especially small threads) is a complex task. It is not always a workpiece with damage (i.e., with defects), and the external thread can also be replaced with a new external thread due to long lead time or high overall cost. Another problem with most known repair tools is that these repair tools do not perform the repair of damaged threads in this way. Instead, the damaged thread is cut by the tool to make the thread workable again. Obviously, cutting the damaged thread leads to the removal of a part of the material made of the thread, which leads to a weakening of the thread after repair, especially weakening of threads with a small pitch. Another problem is that the diameter of the thread after repair is slightly smaller than the required diameter.

[0003] The closest analogue of the pending invention is a thread rolling tool disclosed in US10543524 B2 and intended to repair or roll an external thread. The known tool comprises a base body and an arm connected to the base body by a snap connection. A slide is movably mounted in the base body. When the base body and the arm are closed, the slide body can be moved forward and backward, or moved to and from the arm, respectively, by means of a set screw. The base body is provided with two reverse rollers, and the slide body is provided with a forming roller. When the tool is closed, the rollers perform the repair of the damaged external thread and apply rotation to it around the thread. The advantage of this closest analogue over other known tools is high functionality. It can be used for a wide range of external threads and also allows reducing the effect of cutting the thread being repaired.

[0004] The drawback of the closest analogues is that in some cases the diameter of the repaired thread appears to be smaller than that required, for example, according to the ISO standard, because too much material is removed in an attempt to restore the original shape of the thread. However, the teeth of the thread can still remain in accordance with the ISO standard, which means that it is fully formed, even if the diameter becomes smaller than required or specified. This is due, among other reasons, to the fact that, in the known tools, the working plane defining the effective working direction of the roller is parallel to the set screw that moves the slide with the forming roller mounted thereon. Here, the working plane is always in a constant position.

[0005] Furthermore, the shape of the closest analog is not suitable for use with an external tool such as a power screwdriver which may be required in some cases. For example, if the external thread to be repaired is made of a hard material, the use of a power screwdriver may be superior to a manually operated tool in terms of the time and effort required to repair the external thread to the desired quality. Summary of the invention

[0006] The object of the present invention is therefore to provide a thread repair tool for repairing external threads which eliminates the disadvantages of known tools, allows only reshaping the thread profile instead of cutting it, while maintaining the desired diameter of the thread, and offers the possibility of easily operating the claimed thread repair tool using an external tool.

[0007] The technical effect of the present invention is to repair the external thread and avoid cutting it when reshaping the external thread material, while maintaining the diameter of the external thread at a desired value.

[0008] To achieve the above-mentioned purpose and technical effect, a thread repair tool for repairing an external thread includes a first tool body, a second tool body, at least one first roller mounted on the first tool body, and at least two second rollers mounted on the second tool body. The first tool body and the second tool body are movably connected to each other at their first ends, and each of the tool bodies has an arc shape so as to form a ring shape when the thread repair tool is in a closed state.

[0009] Although the claimed thread repair tool equipped with a first roller and a second roller of a given diameter and a given pitch allows repairing an external thread substantially having a specific diameter and a specific pitch, it has been demonstrated to reshape the external thread so as to fully maintain its desired diameter. In contrast to the closest analogs, due to the curved shape of the bodies, the working plane of the claimed tool moves when starting to close the first tool body and the second tool body.

[0010] Some of the first and second rollers may be made to float along the axis on which they are mounted. This will allow the user to better control the initial engagement of the rollers with the thread to be repaired.

[0011] Furthermore, the thread repair tool may be provided with a fixing device to securely and precisely fix the first tool body against the second tool body in the closed state of the claimed tool, thus providing a more precise handling of the thread to be repaired. In particular, the fixing device may be made in the form of a screw, but other variants are also possible.

[0012] Furthermore, the thread repair tool may be provided with a stopper for fixing the first tool body and the second tool body in any intermediate relative position, for example for initial processing of the thread to be repaired and subsequently fully closing the tool for final processing.

[0013] It is also preferred that if both the first tool body and the second tool body are provided with a hexagonal head portion at their side surfaces, the hexagonal head portion forms a closed hexagonal head shape when the thread repair tool is in a closed state. This will make the claimed tool more convenient to use with an external tool (such as an electric screwdriver, etc.).

[0014] Further, at least one of the rollers may be configured to vibrate, preferably at a frequency of up to 20 kHz or more. This provides a more accurate and precise repair of the external thread and in some cases, such as printed threads, increases its density, especially for threads made of hard materials, and helps to homogenize the structure of the material of the external thread. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be described in more detail with reference to the accompanying drawings, in which:

[0016] Figure 1 An overall view of the claimed thread repair tool in an open state is provided;

[0017] Figure 2 An overall view of the claimed thread repair tool in a closed state is provided;

[0018] Figure 3 A side view of the claimed thread repair tool in an open state is provided;

[0019] Figure 4 A side view of the claimed thread repair tool in a closed state is provided;

[0020] Figure 5 An overall view of the claimed thread repair tool in use is provided. DETAILED DESCRIPTION

[0021] The thread repair tool 1 comprises a first tool body 2 and a second tool body 3 movably connected to each other at a first end 2.1 and a first end 3.1 thereof, respectively. Figure 3 As shown by the arrows in FIG. 2 , the second end 2.2 of the first tool body 2 and the second end 3.2 of the second tool body 3 are respectively free to move.

[0022] Figure 1 The open state of the thread repair tool 1 is shown when the second end 2.2 and the second end 3.2 are away from each other, and Figure 2 In FIG. 1 , the thread repair tool 1 is shown in its closed state when the second end 2.2 and the second end 3.2 are close to each other, preferably in contact with each other.

[0023] The first tool body 2 and the second tool body 3 both have similar curved shapes or arc shapes. More specifically, as Figure 3 As shown, the tool bodies 2 , 3 both have a substantially semi-annular shape, so that when the thread repair tool 1 is in a closed state, the thread repair tool 1 has an annular shape.

[0024] The first tool body 2 comprises at least one first roller 4 mounted thereon. The first roller 4 is made rotatable about its axis (or the axis of the pin 5), and in addition but not necessarily, the first roller can move along said axis, i.e. float, to better control the initial engagement of the roller 4 with the thread to be repaired.

[0025] The second tool body 3 comprises at least two second rollers 6 mounted thereon, for example by means of pins 7 or the like. Each of the second rollers 6 is made rotatable about its axis (or the axis of the corresponding pin 7), and in addition, but not necessarily, the second rollers 6 are movable along said axis, i.e. floating, to better control the initial engagement of the rollers 6 with the thread to be repaired.

[0026] Each of the rollers 4 , 6 is provided on its outer surface with a thread which corresponds only to the outer thread to be repaired with regard to the diameter and pitch of the outer thread to be achieved.

[0027] Although one first roller 4 and two rollers 6 are sufficient for repairing the external thread, more rollers may be advantageous, for example when the diameter of the external thread is large or the external thread is made of a hard material.

[0028] To repair the external thread 8 (see Figure 5 ), the thread repair tool 1 is opened, and the external thread 8 is arranged between the rollers 4 and 6. Then, the thread repair tool 1 is closed so that the rollers 4 and 6 are in contact with the external thread 8, and rotation is applied to the thread repair tool 1. Only a few turns are sufficient to repair the external thread 8. However, more turns may be required depending on the degree of damage to the external thread 8, the material from which the external thread 8 is made, and some other factors.

[0029] If roller 4, roller 6 are made interchangeable, then thread repair tool 1 can be used for external threads of different diameters. In this case, the user replaces roller 4, roller 6 with those rollers with required diameter and pitch, and continues to repair external thread 8 as mentioned above.

[0030] Typically, when the thread repair tool 1 is in a fully closed state, the external thread 8 is repaired, such as Figure 2 , Figure 4 , Figure 5In order to securely fix the thread repair tool 1 in this position, the fixing device 9 may be provided at the second end 2.2 of the first tool body 2 and / or the second end 3.2 of the second tool body 3. For example, the fixing device 9 may be a screw, such as Figure 1 , Figure 5 shown.

[0031] However, it may be preferred if the first turn (or the first few turns) is performed when the thread repair tool 1 is not completely closed (i.e. there is a gap between the second end 2.2 and the second end 3.2). For example, when a stepwise repair is preferred, it may be the choice of large-sized external threads or hard materials. In this case, the thread repair tool 1 may be provided with a stop (not shown in the figure) which allows the relative position of the tool bodies 2, 3 to be fixed.

[0032] In addition or in addition, the thread repair tool 1 may be provided with means for connecting (engaging) an external tool available on the market, such as a mechanical or electric screwdriver. For this purpose, the means may be hexagonal head portions 10, 11 provided on the side surfaces of the first tool body 2 and the second tool body 3, respectively. When the thread repair tool 1 is in the closed position, the hexagonal head portions 10, 11 form a closed hexagonal head shape, such as Figure 2 , Figure 5 Using an external tool engaging said hexagonal head allows a higher force to be applied to the thread repair tool 1 , also more evenly and more precisely, which will positively affect the shape of the repaired external thread.

[0033] It is preferred if the claimed thread repair tool 1 is designed so that at least one of the rollers 4, 6 is configured to vibrate preferably at a frequency of up to 20kHz or more. The vibration may be substantially in a direction perpendicular to the pins 5, 7, i.e. perpendicular to the axis of the external thread 8 being repaired and the axis of the pins 5, 7, or substantially in a direction along the axis of the external thread 8 and the pins 5, 7, or in a combination of said directions. The amplitude of the vibration may be small, for example smaller than the pitch of the external thread 8.

[0034] The vibration can be provided by any vibration device (not shown) or actuator, which is obvious to those skilled in the art. For example, an actuator can be incorporated into the claimed thread repair tool 1, connected to at least one of the pins 5 and 7 and forcing the corresponding pins 5 and 7 to vibrate in any of the above directions. Alternatively, the vibration device can be any suitable external tool, for example, a specially designed electric screwdriver with a dedicated mechanism, which contacts or engages with the corresponding pins 5 and 7 and causes the corresponding pins to vibrate. However, other variations that force at least one pin 5 and 7 to vibrate are also possible. Obviously, the vibrating pins 5 and 7 should be configured to allow movement in the desired direction.

[0035] In fact, it is a reciprocating vibration of the first roller 4 and the second roller 6 with a small amplitude and a relatively high frequency. It provides a more accurate and precise repair of the external thread 8, especially an external thread made of a hard material, and also helps to homogenize the structure of the material and, in some cases, increase the density of the external thread 8 by breaking up large pieces like carbide islands within the external thread 8 into small islands, thereby increasing the density of the material of the external thread 8.

[0036] Thus, the claimed thread repair tool for external threads allows for immediate reshaping of the thread profile instead of cutting it, thereby maintaining the desired diameter of the thread, and is easy to operate with an external tool.

Claims

1. A thread repair tool for repairing an external thread, comprising: a first tool body having a first end and a second end; a second tool body having a first end and a second end; at least one first roller mounted on the first tool body; as well as at least two second rollers, the at least two second rollers being mounted on the second tool body, wherein the first tool body and the second tool body are movably connected to each other at a first end of the first tool body and a first end of the second tool body, thereby providing an open state and a closed state of the thread repair tool when the second end of the first tool body and the second end of the second tool body are away from each other and approach each other, respectively; and Wherein, the first tool body and the second tool body both have an arc shape to form a ring shape when the thread repair tool is in a closed state.

2. The thread repair tool according to claim 1, wherein: At least one of the at least one first roller and the at least two second rollers is made floating.

3. The thread repair tool according to claim 1, further provided with a fixing device, wherein the fixing device is located at the second end of the first tool body and / or the second end of the second tool body.

4. The thread repair tool according to claim 3, wherein: The fixing means are made in the form of screws. 5 . The thread repair tool according to claim 1 , further comprising a stopper for fixing a relative position of the first tool body and the second tool body.

6. The thread repair tool according to claim 1, wherein: The first tool body and the second tool body are each provided with a hexagonal head portion at a side surface thereof, and when the thread repair tool is in the closed state, the hexagonal head portion forms a closed hexagonal head shape.

7. The thread repair tool according to claim 1, wherein: At least one of the rollers is configured to vibrate at a given frequency.

8. The thread repair tool according to claim 7, wherein: The given frequency is up to 20 kHz.

Images