Male Screw Repair Tool

Abstract

The present invention relates to a means for repairing a male screw. The thread repair tool (1) comprises a first tool body (2), a second tool body (3), and rollers (4, 6) respectively attached to the tool bodies (2, 3). 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), and each of the aforementioned tool bodies (2, 3) has a warped shape, so that when the thread repair tool (1) is in a closed state, it forms a ring shape. The technical effect of the present invention is to repair the male screw by reforming the material of the thread while maintaining the required diameter value of the male screw and avoiding its cutting.

Description

Summary of the Invention

[0001] The present invention relates to a means for repairing male threads.

[0002] The repair of male threads, i.e., external threads, especially the repair of small ones, is known to be a complex operation. A workpiece with damaged male threads, in other words, a defective one, cannot always be replaced with a new one due to the long lead time and high total cost. Another concern regarding many of the known repair tools is that they do not actually perform the repair of the damaged thread itself. Rather, the damaged thread by the aforementioned tools is cut in order to be reusable. Naturally, when cutting the damaged thread, a part of the material constituting the thread is removed, which leads to the weakening of the repaired thread, especially those with a small pitch. Another concern is that the diameter of the repaired thread is slightly smaller than the required size.

[0003] The closest analogue to the present invention is the thread rolling tool disclosed in US Patent No. 10543524, which is intended for the repair or rolling of male threads. This known tool comprises a base body and an arm connected thereto by snap connection means. In the base body, a slide is movably attached. When the base body and the arm are closed, the slide body can be moved back and forth or towards and away from the arm respectively by means of a set screw. Two counter rollers are provided on the base body, and a profiled roller is provided on the slide body. The rollers perform the repair of the damaged male thread in the closed state of the tool and apply rotation thereto around the thread. The advantage of this closest analogue over other known tools of this kind is its high functionality. It can be used for a wide range of male threads and can suppress the influence of cutting the thread during repair.

[0004] The drawback of this closest prior art is that as an excessive amount of material is removed in an attempt to restore the initial shape of the thread, the diameter of the thread being repaired sometimes becomes smaller than the required size, for example, smaller than the size according to ISO standards. However, the teeth of the thread can be maintained in a state that conforms to the ISO standard, that is, even if the diameter becomes smaller than the required size, i.e., the specified size, the teeth of the thread are formed in a complete state. Leaving other reasons aside, this is because in this known tool, the working surface that determines the effective working direction of the roller and the setscrew that moves the slide to which the profiled roller is attached are parallel. Here, the working surface is always in a fixed position.

[0005] Furthermore, the shape of this closest prior art is not suitable for using a thread repair tool together with an external tool such as an electric driver that may be required in a specific case. For example, when the male thread to be repaired is made of a hard material, in terms of the time and labor required to repair the male thread with the required quality, the use of an electric driver may be more beneficial than manually operating the tool.

[0006] Accordingly, an object of the present invention is to provide a thread repair tool for repairing a male thread that eliminates the drawbacks of known tools and enables the outer shape of the thread to be simply reformed to its original state without cutting while maintaining the required diameter of the thread, and also to provide the possibility of convenient use of an external tool for operating the claimed thread repair tool.

[0007] The technical result of this invention is to repair the male thread by reforming the material of the thread while keeping the diameter of the male thread at the required value and avoiding cutting.

[0008] To achieve the above object and technical result, a thread repair tool for male thread repair comprises a first tool body, a second tool body, at least one first roller attached to the first tool body, and at least two second rollers attached to 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 above-mentioned tool bodies has a warped shape so as to form a ring shape when the thread repair tool is in a closed state.

[0009] The claimed thread repair tool, comprising first and second rollers having a predetermined diameter and a predetermined pitch, enables the repair of male threads having substantially a specific diameter and a specific pitch, and it has been proven that the male thread is reformed while maintaining the required diameter sufficiently. Unlike the closest prior art, due to the warped shape of the body, the working surface of the claimed tool moves when the first and second tool bodies start to close.

[0010] Some of the above-mentioned first and second rollers may be adapted to float along the axis to which they are attached. This enables the user to better control the initial engagement between the thread to be repaired and the rollers.

[0011] Furthermore, the thread repair tool may comprise fixing means for securely and accurately fixing the first tool body to the second tool body in the closed state of the claimed tool, thereby providing more precise handling of the thread to be repaired. In particular, the fixing means may be formed in the shape of a screw, although other shapes are also possible.

[0012] Still further, the thread repair tool may comprise a stopper for fixing the first and second tool bodies in an arbitrary intermediate relative position, for example, this is for completely closing the tool for the final treatment after the initial treatment of the thread to be repaired.

[0013] Also, it is preferable that each of the first tool body and the second tool body has a hexagonal head on its side surface, and when the thread repair tool is in a closed state, the hexagonal heads form the shape of a closed hexagonal head. This makes the claimed tool more convenient to use with external tools such as, for example, an electric driver or the like.

[0014] Furthermore, at least one of the rollers may preferably be configured to vibrate at a frequency of up to 20 kHz or more. This provides more accurate and precise male thread repair, increasing the density in the case of, for example, printed threads, which is particularly significant for threads made of hard materials, and also helps to homogenize the structure of the male thread material.

[0015] This invention is further described in more detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0017] As shown by the arrows in Fig. 3, the thread repair tool 1 includes a first tool body 2 and a second tool body 3 that are movably connected to each other at a first end 2.1 and a first end 3.1, respectively. The second ends 2.2 and 3.2 of the first tool body 2 and the second tool body 3 can move freely, respectively.

[0018] Fig. 1 shows the open state of the thread repair tool 1 when the second ends 2.2 and 3.2 are separated from each other, while Fig. 2 shows the closed state of the thread repair tool 1 when the second ends 2.2 and 3.2 are adjacent to each other and preferably in contact with each other.

[0019] Both the first tool body 2 and the second tool body 3 have a similar curved shape, in other words, a warped shape. More specifically, as can be clearly seen in Fig. 3, the aforementioned tool bodies 2 and 3 each have a substantially semi-circular shape, and when the thread repair tool 1 is in the closed state, it is shaped like a ring as shown in Fig. 4.

[0020] The first tool body 2 includes at least one first roller 4 attached by, for example, a pin 5 or similar means. The first roller 4 is made rotatable about its axis (or the axis of the pin 5), and further, although not necessarily required, it may be movable along the axis in order to better control the initial engagement between the roller 4 and the thread to be repaired, in other words, it may float.

[0021] The second tool body 3 includes at least two second rollers 6 attached by, for example, a pin 7 or similar means. Each of the second rollers 6 is made rotatable about its axis (or the axis of each pin 7), and further, although not necessarily required, it may be movable along the axis in order to better control the initial engagement between the roller 6 and the thread to be repaired, in other words, it may float.

[0022] On each of the roller 4 and the roller 6, a thread that simply corresponds to the male screw being repaired in terms of the diameter and pitch of the male screw to reach the standard is provided on its outer surface.

[0023] For repairing the male screw, one first roller 4 and two rollers 6 are sufficient. However, for example, when the diameter of the male screw is large or the male screw is made of a hard material, it may be convenient to have more rollers.

[0024] To repair the male screw 8 (see Fig. 5), open the thread repair tool 1 and place the male screw 8 between the roller 4 and the roller 6. Next, close the thread repair tool 1 to bring the roller 4 and the roller 6 into contact with the male screw 8, and apply rotation to the thread repair tool 1. Probably, only a slight rotation is sufficient to repair the male screw 8. However, depending on the degree of damage of the male screw 8, the material constituting the male screw 8, and other factors, more rotations may be required.

[0025] If the rollers 4 and 6 are made replaceable, the thread repair tool 1 can be used for male screws of different diameters. In this case, the user replaces the rollers 4 and 6 with those having the required diameter and pitch, and then repairs the male screw 8 as described above.

[0026] In many cases, as shown in Figs. 2, 4, and 5, the male screw 8 is repaired when the thread repair tool 1 is in a completely closed state. For the purpose of securely fixing the thread repair tool 1 in this position, the fixing means 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 means 9 may be a screw as shown in Figs. 1 and 5.

[0027] However, in some cases, it may be preferable to perform the first rotation (or the first few rotations) when the thread repair tool 1 is not fully closed, that is, when there is a gap between the second end portion 2.2 and the second end portion 3.2. For example, this can be an option for male threads made of hard materials or large sizes when step-by-step repair is desired. In this case, the thread repair tool 1 may be provided with a stopper (not shown) that enables fixing of the relative positions of the tool body 2 and the tool body 3.

[0028] Furthermore, alternatively or in addition to this, the thread repair tool 1 may be provided with means for connecting (engaging) to a commercially available external tool, such as a mechanic screwdriver or an electric screwdriver, for example. For this purpose, the means may be hexagonal heads 10 and hexagonal heads 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, as shown in FIGS. 2 and 5, the hexagonal heads 10 and the hexagonal heads 11 form a closed hexagonal head shape. By using an external tool that engages with the hexagonal head, a large force can be applied to the thread repair tool 1, and the force can be applied more uniformly and accurately, which will have a positive impact on the shape of the male thread after repair.

[0029] The claimed thread repair tool 1 is preferably designed such that at least one of the rollers 4 and 6 is configured to vibrate, preferably at a frequency of at most 20 kHz or more. The vibration may be performed substantially in a direction perpendicular to the pins 5 and 7, in other words, in a direction perpendicular to the axis of the male thread 8 being repaired and the axes of the pins 5 and 7, or substantially in a direction along the axes of the aforementioned male thread 8 and the pins 5 and 7, or a combination of the aforementioned directions. The amplitude of the aforementioned vibration may be small, for example, smaller than the pitch of the male thread 8.

[0030] The above-mentioned vibration may be imparted by any vibration means (not shown) or an actuator, which is probably self-evident to those skilled in the art. For example, the actuator may be incorporated into the claimed thread repair tool 1 and connected to at least one of the pins 5 and 7, and each of the pins 5 and 7 may be vibrated in any of the above directions. Alternatively, the vibration means may be any suitable external tool, for example, a specially designed electric driver having a dedicated mechanism that contacts or engages each of the pins 5 and 7 and vibrates the latter. However, other variations of vibrating at least one of the pins 5 and 7 are also possible. Of course, the vibrating pins 5 and 7 need to be configured to be able to move in the required directions.

[0031] In fact, this is the mutual vibration of the first roller 4 and the second roller 6 with a small amplitude and a relatively high frequency. This provides a more accurate and precise repair of the male thread 8 made of a particularly hard material, and it also helps to make the structure of the material homogeneous. In some cases, it helps to increase the density of the male thread 8 by breaking a large piece such as a carbide island in the male thread 8 into small islands.

[0032] Therefore, the claimed thread repair tool for male threads reforms the shape of the thread back to its original state instead of cutting the thread, while maintaining the required diameter of the thread, and further enables the convenient use of an external tool for operating the claimed thread repair tool.

Claims

1. A thread repair tool for repairing a male thread, wherein the thread repair tool comprises: a first tool body having a first end portion and a second end portion; a second tool body having a first end portion and a second end portion; at least one first roller attached to the first tool body; at least two second rollers attached to the second tool body; The first tool body and the second tool body are movably connected to each other at their first end portions, and when the second end portions are separated from each other and when they are adjacent to each other, the thread repair tool provides an open state and a closed state respectively. The first tool body and the second tool body each have a warped shape so as to form a ring shape when the thread repair tool is in the closed state. Thread repair tool.

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 to float.

3. The thread repair tool according to claim 1, further comprising fixing means located at the second end portion of the first tool body and / or at the second end portion of the second tool body.

4. The thread repair tool according to claim 3, wherein the fixing means is formed in the shape of a screw.

5. The thread repair tool according to claim 1, further comprising a stopper for fixing the relative positions 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 each have a hexagonal head on their side surfaces, and when the thread repair tool is in the closed state, the hexagonal heads form a closed hexagonal shape.

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

8. The thread repair tool according to claim 7, wherein the predetermined frequency is 20 kHz or less. ​

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