JP7789314B2 - Bolt and nut marking tools - Google Patents

Description

This invention relates to a bolt and nut marking tool used to mark bolts, nuts, washers, and fastened components, such as steel, after the initial tightening process when joining fastened components using bolts, nuts, and washers.

When fastened components such as steel materials are joined with bolts, nuts, and washers in steel frame construction, these fastening components are tightened in the following order: primary tightening, marking, and final tightening. Specifically, the nut is first rotated to a specified torque value to perform primary tightening, and a series of linear marks are made on the bolt, nut, washer, and fastened components (collectively referred to as "marking objects") that have been primarily tightened. Final tightening is then performed, and by inspecting the positional deviation angle of the linear marks made on the marking objects during primary tightening, it is possible to determine whether the bolts and nuts are rotating or axially rotating.

Marking is generally done manually using a pen or similar tool, but the task of writing by hand on numerous objects one by one is a significant burden. Furthermore, in dangerous locations such as high places or locations where workers are forced to assume awkward positions, it is difficult to mark accurately or ensure worker safety using handwriting. Therefore, a bolt and nut marking tool that can mark bolts and other objects has been proposed.

Patent Documents 1 and 2 describe bolt and nut marking tools that include a roller arm rotatably supported on a marking holder, with a marking roller supported on the end of the roller arm. However, with these bolt and nut marking tools, when the marking roller is pressed against a surface that is approximately perpendicular to the axial direction of the bolt, such as the top surface of a nut or a washer, the roller arm rotates, causing the marking roller to move away from the top surface. As a result, the marking roller cannot contact approximately right-angled corners that are the boundaries between components, such as the boundary between a bolt and a nut or the boundary between a washer and a fastened component, resulting in broken marks and preventing clear, continuous linear markings.

Patent No. 5953877 Patent No. 6056995

The object of the present invention is to provide a bolt and nut marking tool that solves the above-mentioned conventional problems, suppresses marking discontinuities, and allows for the creation of clear, continuous marks in a straight line.

To solve the above problem, a bolt and nut marking tool is provided that includes a marking holder that is placed over the fastened bolt, nut, or washer (the object to be marked) and is movable from the tip to the base end of these fastening members, and a marking roller that is attached to the marking holder so that it can be displaced only in a direction approximately perpendicular to the axial direction of the bolt.

It is also preferable that the marking roller is held and attached by a roller holding member provided on the marking holder.

Furthermore, it is preferable that the support shaft of the marking roller engages with a horizontal groove extending in a direction approximately perpendicular to the axial direction of the bolt and slides freely within the horizontal groove, and it is even more preferable that the marking roller be equipped with an elastic body that biases it in a direction approaching the shank of the bolt.

Furthermore, it is preferable that a guide slider that fits over the fastened bolt, nut, and washer is provided below the marking holder, and that the marking holder be configured to be slidable relative to the guide slider in the axial direction of the bolt.

This invention makes it possible to provide a marking tool for bolts and nuts that can produce clear, continuous marks in a straight line, while minimizing the need for interrupted marks.

FIG. 1 is a front view of a bolt and nut marking tool according to an embodiment. 1 is a central vertical cross-sectional view of a bolt and nut marking tool according to an embodiment, showing the tool attached to a primarily tightened bolt that is the target of marking. 2 is an enlarged view of the main part of FIG. 1, showing the marking roller and the roller holding member. FIG. 4 is a bottom view of the marking roller and the roller holding member shown in FIG. 3 . 3 is a cross-sectional view showing the state in which the bolt and nut marking tool shown in FIG. 2 is pressed down in a direction approaching the fastened member, and the marking roller comes into contact with the top surface of the nut or the like. FIG. 6 is a cross-sectional view showing a state in which the bolt and nut marking tool shown in FIG. 5 is further pressed down so that the marking roller is pressed against a corner portion that is the boundary between members such as a bolt and a nut. 6 is an explanatory diagram showing the resultant force acting on the support shaft, in which hatching of the cross section is omitted.

The following describes an embodiment of the invention. As shown in Figures 1 and 2, the bolt and nut marking tool 1 of this embodiment comprises a marking holder 2 that is generally cylindrical overall, and a marking roller 3 that is rotatably supported inside the marking holder 2.

As shown in Figure 2, the bolt and nut marking tool 1 is used to make linear marks on the surfaces of fastening members such as bolts 4, nuts 5, and washers 6, and of fastened members 7 (71, 72) such as steel materials fastened by these fastening members, the fastened member 71 is located on the fastening member side.

The marking holder 2 is placed over the fastened bolt 4, nut 5, and washer 6, which are the objects to be marked, and is moved from the tip to the base end of these fastening members. As shown in Figures 1 and 2, the marking holder 2 of this embodiment has a hollow body 21 that is open on the lower side in the figure and is sized to fit over the fastening member, and a protrusion 22 with a roughly U-shaped cross section that is formed integrally with the body 21 and can accommodate at least part of the mounting mechanism for the marking roller 3.

The marking roller 3 is capable of applying a substantially linear mark to an object to be marked by rotating and contacting it. The marking roller 3 of this embodiment is a felt printing element that can be impregnated with marking ink, and is equipped with a support shaft 31 that serves as the center of rotation. The ink impregnated into the marking roller 3 is not particularly limited, as long as it is ink that can be used for outdoor marking. While it is possible to provide an ink reservoir that supplies ink to the marking roller 3, the ink-impregnated system of this embodiment contributes to the miniaturization of the bolt and nut marking tool 1. Furthermore, while the bolt and nut marking tool 1 of this embodiment is equipped with two marking rollers 3 (3A, 3B), it can also be equipped with one or three or more marking rollers 3.

As shown in Figure 2, a roller holding member 23 that holds the marking roller 3 is provided inside the convex portion 22 of the embodiment. Note that the marking roller 3 is not limited to being held by the roller holding member 23 as in the embodiment, but may be directly attached to the marking holder 2. As shown in Figures 3 and 4, the roller holding member 23 of the embodiment has a pair of wall portions 24 that are generally L-shaped when viewed from the front, and the marking roller 3 (3A, 3B) is disposed between the opposing wall portions 24, 24.

The wall portion 24 is provided with a horizontal groove 25 into which the support shaft 31 can engage. In this embodiment, the horizontal groove 25 is an elongated hole that extends in a direction approximately perpendicular to the axial direction of the bolt 4 when assembled to the marking holder 2. The support shaft 31 (31A, 31B) engaged with the horizontal groove 25 can slide freely within the horizontal groove 25 along its longitudinal direction. This allows the marking roller 3 to be supported so that it can be displaced only in a direction approximately perpendicular to the axial direction of the bolt 4 housed inside the marking holder 2.

In this embodiment, horizontal grooves 25 (25A, 25B) are formed in each wall portion 24, 24, and horizontal grooves 25A and 25B are positioned so that their centers are offset from each other in the vertical and horizontal directions. As a result, the upper marking roller 3A in Figure 3 is positioned relatively closer to the center of the marking holder 2, and the lower marking roller 3B in Figure 3 is positioned further outward than the marking roller 3A.

With this configuration, marks can be applied to approximately the upper half of the object using marking roller 3A, and to approximately the lower half using marking roller 3B. This shortens the stroke distance of the bolt and nut marking tool 1, allowing the longitudinal size of the marking holder 2 to be reduced.

As shown in Figures 2 and 4, the roller holding member 23 of this embodiment is provided with a leaf spring 26, which is an elastic body that urges the marking roller 3 in a direction approaching the shaft 41 of the bolt 4. In this embodiment, two leaf springs 26 are provided for one marking roller 3, and these leaf springs 26 press the support shaft 31 toward the inside of the marking holder 2. This urges the marking roller 3 in a direction that brings it into close contact with the object to be marked.

The bolt and nut marking tool 1 is also preferably provided with a guide slider 8, which is an inner tube sized to fit over the fastened bolt 4, nut 5, and washer 6 of the object to be marked. As shown in Figures 1 and 2, the guide slider 8 in this embodiment is provided below the marking holder 2, and is slidable up and down relative to the marking holder 2. A return compression coil spring 81 is provided between the top surface of the marking holder 2 and the top surface of the guide slider 8.

In this embodiment, the guide slider 8 fits along the inner surface of the body 21 of the marking holder 2, allowing them to slide up and down relative to each other. Therefore, the marking roller 3 is naturally positioned inside the guide slider 8. Therefore, the guide slider 8 in this embodiment is formed with a slit 82 large enough to allow the roller holding member 23 to pass through, so that the marking roller 3 does not interfere with the guide slider 8 even when the marking holder 2 slides.

A bolt and nut marking tool 1 equipped with this guide slider 8 allows for accurate and easy positioning when placing the tool on the bolt 4. Furthermore, because the guide slider 8 is biased by a compression coil spring 81, it automatically returns to its initial position after the marking operation, providing excellent continuous marking capabilities.

Next, the behavior of the bolt and nut marking tool 1 in this embodiment when applying a mark to an object to be marked will be described. First, as shown in Figure 2, the bolt and nut marking tool 1 in this embodiment is placed over the bolt 4, nut 5, and washer 6, which are the primary tightened fastening components, and the lower end of the guide slider 8 is brought into contact with the surface of the fastened component 71. In this state, both the upper marking roller 3A and the lower marking roller 3B in the figure are spaced apart from the object to be marked.

Next, the marking holder 2 is pressed toward the fastened member 71 and moved from the tip to the base end of the bolt 4. This causes the marking roller 3A to come into contact with the shank 41 of the bolt 4, and the marking roller 3B to come into contact with the upper edge of the nut 5, which is the boundary between the top surface 51 and the outer surface 52.

When the marking holder 2 is further pressed, the marking roller 3 moves toward the base end of the bolt 4 while contacting the surface of the object to be marked, leaving a mark along its trajectory. Then, as shown in Figure 5, the marking roller 3A comes into contact with the top surface 51 of the nut 5, and the marking roller 3B comes into contact with the top surface 61 of the washer 6 and the surface of the fastened member 71.

Furthermore, as shown in Figure 6, when the marking holder 2 is pressed until its lower end abuts the fastened workpiece 71, the marking roller 3A, which receives a pressing force from above in the figure, is pressed against the top surface 51 of the nut 5, and the marking roller 3B is pressed against the top surface 61 of the washer 6 and the surface of the fastened workpiece 71.

At this time, the marking roller 3 is subjected to a force pushing downward in the figure, as well as an upward stress from the object to be marked. In this embodiment, the engagement between the support shaft 31 and the horizontal groove 25 restricts the movement of the marking roller 3 in the vertical direction in the figure, preventing the marking roller 3 from escaping in the upward direction in the figure. This causes the marking roller 3 to be compressed and deformed to conform to the uneven shape of the object to be marked.

This allows the marking roller 3 to adhere closely to the approximately right-angled corners S (S1, S2, S3) that form the boundaries between components, such as the boundary between the bolt 4 and nut 5 or the boundary between the washer 6 and the fastened member 71, preventing the mark from being interrupted and leaving a clear, continuous mark in a straight line. Furthermore, depending on the size of the nut 5 and marking roller 3, it is possible that the marking roller 3 will not adhere closely to the corner S, such as the corner S2 between the nut 5 and washer 6 shown in Figure 6. However, even in this case, the compressed deformation of the marking roller 3 will eject the impregnated ink, preventing the mark from being interrupted.

Furthermore, if a leaf spring 26, which is an elastic body that biases the support shaft 31 in a direction approaching the central axis of the bolt 4, is provided, the marking roller 3 is further pressed against the corners S (S1, S3). Specifically, as shown in Figure 7, a force P pressing downward on the support shaft 31 in the figure and a biasing force F from the leaf spring 26 are applied, and the resultant force R presses the marking roller 3 against the corners S (S1, S3). This allows the bolt and nut marking tool 1 to produce even clearer markings.

The present invention has been described above using exemplary embodiments, but the present invention is not limited to these and can be implemented in various other forms. For example, the embodiment is configured so that marks can be placed at any position on either the flat surface or corner of the outer surface 52 of the nut 5, but it is also possible to provide a positioning member that guides the position of the marking roller 3 so that the mark is placed at a specific position.

In addition, in the case of a bolt and nut marking tool 1 that does not include a roller holding member 23,
The marking holder 2 may be configured to have a horizontal groove 25 and/or a leaf spring 26 provided therein.

REFERENCE SIGNS LIST 1 Bolt and nut marking tool 2 Marking holder 21 Body 22 Convex portion 23 Roller holding member 24 Wall portion 25 Horizontal groove 26 Leaf spring 3 Marking roller 31 Support shaft 4 Bolt 41 Shaft portion 5 Nut 51 Top surface 52 Outer surface 6 Washer 61 Top surface 7 Fastened member 8 Guide slider 81 Return spring 82 Slit

Claims (5)

a marking holder that is placed over the fastened bolt, nut, and washer and is movable from the tip to the base end;
a marking roller attached to the marking holder so as to be displaceable only in a direction substantially perpendicular to the axial direction of the bolt ,
The marking roller is a marking tool for bolts and nuts that can be deformed to conform to the uneven shape of the object to be marked when compressed . The bolt and nut marking tool according to claim 1, wherein the marking roller is held and attached by a roller holding member provided on the marking holder. A bolt and nut marking tool as described in claim 1 or 2, wherein the support shaft of the marking roller engages with a horizontal groove extending in a direction approximately perpendicular to the axial direction of the bolt and slides freely within the horizontal groove. A bolt and nut marking tool according to any one of claims 1 to 3, further comprising an elastic body that biases the marking roller in a direction approaching the bolt shaft. A bolt and nut marking tool according to any one of claims 1 to 4, wherein a guide slider that fits over the fastened bolt, nut, and washer is provided below the marking holder, and the marking holder is slidable relative to the guide slider in the axial direction of the bolt.