Hexagonal rod manual ultrasonic water immersion detection assisting and identifying device

Abstract

The utility model discloses a hexagonal rod manual ultrasonic water immersion detection assisting and identifying device which comprises a hexagonal rod guide device, the top of the hexagonal rod guide device is connected with a probe mounting bracket, the side wall of the probe mounting bracket is in threaded connection with a probe set screw, and the side wall of the hexagonal rod guide device is connected with an identifying device. According to the device, in the detection process, the distance between the probe and the detection surface and the angle perpendicularity between the probe and the workpiece to be detected can be ensured.

Description

Technical Field

[0001] This utility model belongs to the field of ultrasonic non-destructive testing technology, specifically relating to a hexagonal rod manual ultrasonic water immersion testing auxiliary and marking device. Background Technology

[0002] With the continuous advancement of industrial production technology, material quality control and non-destructive testing (NDT) have gradually become crucial for ensuring product performance and safety. Among these, ultrasonic water immersion testing technology has gained widespread application due to its non-contact, real-time, and high-sensitivity characteristics. Ultrasonic water immersion testing is a commonly used method in ultrasonic testing. Using a water immersion probe with water as a coupling agent effectively reduces the detection blind zone and improves the detection capability for small defects. According to the ultrasonic water immersion testing process, manual ultrasonic water immersion testing requires maintaining a constant distance between the probe and the workpiece, as well as ensuring the probe is perpendicular to the workpiece. In manual ultrasonic water immersion testing of hexagonal bar workpieces, it is difficult for inspectors to maintain the distance and perpendicular angle between the test surfaces by holding the probe for extended periods, leading to low testing efficiency and a risk of missed defects.

[0003] To address these issues, there is an urgent need for a manual ultrasonic water immersion detection and marking device that can adapt to the geometric characteristics of hexagonal rods. Utility Model Content

[0004] The purpose of this invention is to provide a manual ultrasonic water immersion test auxiliary and marking device for hexagonal bars. During the test, it can ensure the distance between the ultrasonic water immersion probe and the test surface of the hexagonal bar under test, as well as ensure that the ultrasonic water immersion probe and the angle between the ultrasonic water immersion probe and the hexagonal bar under test are perpendicular.

[0005] The technical solution adopted in this utility model is a hexagonal bar manual ultrasonic water immersion detection auxiliary and marking device, including a hexagonal bar guide device, a probe mounting bracket connected to the top of the hexagonal bar guide device, a probe set screw threaded to the side wall of the probe mounting bracket, and a marking device connected to the side wall of the hexagonal bar guide device.

[0006] The feature of this utility model is that,

[0007] The hexagonal rod guide device includes a guide device body, a dovetail groove at the top of the guide device body passing through the center point of the upper surface of the guide device body, a through hole in the guide device body along its axial direction, the through hole communicating with the dovetail groove, a trapezoidal groove at the bottom end face of the guide device body, a notch in the side wall of the guide device body communicating with the through hole, the dovetail groove being connected to the probe mounting bracket, and a marking device being connected to the side wall of the guide device body.

[0008] The through hole includes a first through hole section and a second through hole section. The top end of the first through hole section is connected to the dovetail groove, the bottom end of the first through hole section is connected to the second through hole section, and the second through hole section is connected to the notch. The diameter of the first through hole section is smaller than the top width of the dovetail groove, and the diameter of the first through hole section is smaller than the diameter of the second through hole section.

[0009] A first threaded hole is provided on the side wall of the guide device body. The first threaded hole is connected to the dovetail groove, and a locking screw is connected to the internal thread of the first threaded hole.

[0010] The probe mounting bracket includes a mounting bracket body, the bottom of which is provided with a dovetail-shaped protrusion that mates with a dovetail groove, and the top of which is provided with a probe fixing body. The probe fixing body, the mounting bracket body, and the dovetail-shaped protrusion are all coaxially provided with probe guide holes, which are connected to through holes.

[0011] A second threaded hole is provided on the side wall of the probe fixing body, and a probe set screw is threaded into the second threaded hole.

[0012] The marking device includes a front-to-back position adjustment rod, a height adjustment rod, and a left-to-right position adjustment rod. A first strip-shaped hole is provided on the side wall of the front-to-back position adjustment rod along its axial direction. The first strip-shaped hole is connected to the side wall of the guide device body via a marking device connecting screw. A second strip-shaped hole is provided on the side wall of the height adjustment rod along its axial direction. A third strip-shaped hole is provided on the side wall of the left-to-right position adjustment rod along its axial direction. The end of the front-to-back position adjustment rod on the same side as the notch is connected to the third strip-shaped hole via a first connecting screw. The end of the left-to-right position adjustment rod on the same side as the hexagonal bar guide device is connected to the second strip-shaped hole via a third connecting screw. The side wall of the height adjustment rod near the notch is connected to a marking pen holder via a second connecting screw. A pen hole is provided inside the marking pen holder, and a marking pen is inserted into the pen hole. The axis of the marking pen is parallel to the axis of the front-to-back position adjustment rod, and the tip of the marking pen faces the hexagonal bar guide device.

[0013] The side wall of the marker pen holder is provided with a third threaded hole, which is connected to the pen hole and is threaded with a marker pen set screw.

[0014] The beneficial effects of this utility model are:

[0015] (1) The hexagonal bar manual ultrasonic water immersion detection auxiliary and marking device of this utility model can connect the hexagonal bar guide device and the probe mounting bracket by setting dovetail groove and dovetail protrusion. By adjusting the relative position of the dovetail groove and dovetail protrusion, the hexagonal bar guide device and the probe mounting bracket are coaxially set, which is convenient for adjustment and easy to disassemble and install.

[0016] (2) The present invention provides a manual ultrasonic water immersion test auxiliary and marking device for hexagonal bars. By setting a trapezoidal groove 16 at the bottom of the guide device body, the hexagonal bar guide device can be tightly fitted with the hexagonal bar workpiece. By cooperating with the hexagonal bar guide device and the probe mounting bracket, the distance between the ultrasonic water immersion probe and the test surface of the hexagonal bar to be tested can be flexibly adjusted. During the test, the distance between the ultrasonic water immersion probe and the test surface of the hexagonal bar to be tested can be kept constant, which has strong stability. At the same time, it can ensure that the angle between the ultrasonic water immersion probe and the test surface of the hexagonal bar to be tested is perpendicular, which improves the accuracy of the test results.

[0017] (3) The hexagonal bar manual ultrasonic water immersion detection auxiliary and marking device of this utility model can mark the location of the detected defect by setting the marking device, which has high detection efficiency and is easy to operate. Attached Figure Description

[0018] Figure 1 This is the front view of the hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device of this utility model;

[0019] Figure 2 This is a left view of the hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device of this utility model;

[0020] Figure 3 This is a top view of the hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device of this utility model;

[0021] Figure 4 This is a front view of the marking device in the hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device of this utility model;

[0022] Figure 5 This is a left view of the marking device in the hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device of this utility model;

[0023] Figure 6 This is a schematic diagram of the operation of the hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device of this utility model.

[0024] In the figure, 1. Hexagonal bar guide device, 2. Locking screw, 3. Probe mounting bracket, 4. Probe set screw, 5. Marking device connecting screw, 6. Marking device, 7. Ultrasonic water immersion probe, 8. Hexagonal bar workpiece;

[0025] 11. Guide device body; 12. Through hole; 13. Notch; 14. Dovetail groove; 15. First threaded hole; 16. Trapezoidal groove;

[0026] 121. First through-hole section; 122. Second through-hole section;

[0027] 31. Mounting bracket body; 32. Dovetail protrusion; 33. Probe guide hole; 34. Second threaded hole; 35. Probe fixing body;

[0028] 61. Front and rear position adjustment rod; 62. Height and low position adjustment rod; 63. First connecting screw; 64. Second connecting screw; 65. Marking pen; 66. Marking pen set screw; 67. Marking pen holder; 68. Third connecting screw; 69. Left and right position adjustment rod.

[0029] 611. First strip hole, 621. Second strip hole, 671. Third threaded hole, 672. Pen hole, 691. Third strip hole. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] This utility model relates to a hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device, the structure of which is as follows: Figure 1 , Figure 2 and Figure 3 As shown, the device includes a hexagonal bar guide device 1, with a probe mounting bracket 3 connected to its top. The probe mounting bracket 3 is used to mount an ultrasonic water immersion probe 7. The ultrasonic water immersion probe 7 extends into the hexagonal bar guide device 1 through the probe mounting bracket 3. During use, the hexagonal bar guide device 1 is placed on the side wall of a hexagonal bar workpiece 8. Moving the hexagonal bar guide device 1 along the axial direction of the hexagonal bar workpiece 8 allows for the detection of the side wall of the hexagonal bar workpiece 8. By setting the hexagonal bar guide device 1, the distance between the ultrasonic water immersion probe 7 and the hexagonal bar workpiece 8 can be ensured. The distance between the ultrasonic immersion probe 7 and the hexagonal bar workpiece 8 is ensured by the cooperation of the probe mounting bracket 3 and the hexagonal bar guide device 1. The probe mounting bracket 3 is threaded with a probe set screw 4, which is used to fasten the ultrasonic immersion probe 7 and limit the position of the ultrasonic immersion probe 7 to ensure that the distance between the ultrasonic immersion probe 7 and the hexagonal bar workpiece 8 remains unchanged during the test. The hexagonal bar guide device 1 is connected to a marking device 6, which is used to mark the defect location.

[0033] Example 2

[0034] Based on Embodiment 1, the hexagonal bar guide device 1 includes a guide device body 11. A dovetail groove 14 is provided on the top of the guide device body 11. The dovetail groove 14 is used to fix the probe mounting bracket 3. The dovetail groove 14 passes through the center point of the upper surface of the guide device body 11, meaning the axis of the dovetail groove 14 is perpendicular to and coplanar with the axis of the guide device body 11. A through hole 12 is provided inside the guide device body 11 along its axial direction. The through hole 12 communicates with the dovetail groove 14. The through hole 12 allows the ultrasonic water immersion probe 7 to extend into the guide device body 11 to guide the sidewall of the hexagonal bar workpiece 8. The bottom surface of the guide device body 11 is provided with a trapezoidal groove 16, which mates with the hexagonal bar workpiece 8. That is, the three sides of the trapezoidal groove 16 are equal in length. In use, the trapezoidal groove 16 is attached to the side wall of the hexagonal bar workpiece 8. The side wall of the guide device body 11 is provided with a notch 13, which is connected to the through hole 12. When the ultrasonic water immersion probe 7 is installed, air is discharged through the notch 13 during the process of placing the guide device body 11 on the side wall of the hexagonal bar workpiece 8. The dovetail groove 14 is connected to the probe mounting bracket 3. The side wall of the guide device body 11 is connected with an marking device 6.

[0035] Example 3

[0036] Based on Embodiment 2, the through hole 12 includes a first through hole section 121 and a second through hole section 122. The top end of the first through hole section 121 is connected to the dovetail groove 14, and the bottom end of the first through hole section 121 is connected to the second through hole section 122. The second through hole section 122 is connected to the notch 13. The diameter of the first through hole section 121 is smaller than the top width of the dovetail groove 14, and the diameter of the first through hole section 121 is the diameter of the ultrasonic immersion probe 7 plus 0.15 mm. The ultrasonic immersion probe 7 extends into the second through hole section 122 through the first through hole section 121 to detect the side wall of the hexagonal bar workpiece 8. The diameter of the first through hole section 121 is smaller than the diameter of the second through hole section 122.

[0037] Example 4

[0038] Based on embodiment 3, a first threaded hole 15 is provided on the side wall of the guide device body 11. The first threaded hole 15 is connected to the dovetail groove 14. A locking screw 2 is internally threaded into the first threaded hole 15. By tightening the locking screw 2, the end of the locking screw 2 is pressed against the probe mounting bracket 3, thereby limiting and fixing the probe mounting bracket 3 and preventing relative movement between the probe mounting bracket 3 and the guide device body 11.

[0039] Example 5

[0040] Based on embodiment 4, the probe mounting bracket 3 includes a mounting bracket body 31. The bottom of the mounting bracket body 31 is provided with a dovetail-shaped protrusion 32, which cooperates with the dovetail groove 14 to connect the probe mounting bracket 3 with the hexagonal rod guide device 1. The top of the mounting bracket body 31 is provided with a probe fixing body 35. The probe fixing body 35, the mounting bracket body 31, and the dovetail-shaped protrusion 32 are all coaxially provided with probe guide holes 33. The probe guide holes 33 are connected to the through hole 12 and are coaxially arranged with the through hole 12. The diameter of the probe guide hole 33 is the diameter of the ultrasonic water immersion probe 7 plus 0.15mm.

[0041] A second threaded hole 34 is provided on the side wall of the probe fixing body 35. The second threaded hole 34 is threaded with a probe set screw 4, which is used to limit the position of the ultrasonic water immersion probe 7.

[0042] In use, the ultrasonic immersion probe 7 is inserted into the probe guide hole 33 and the through hole 12 in sequence. The distance between the ultrasonic immersion probe 7 and the side wall of the hexagonal bar workpiece 8 is adjusted. After adjustment, the probe set screw 4 is tightened so that the end of the probe set screw 4 presses against the ultrasonic immersion probe 7, thereby limiting the position of the ultrasonic immersion probe 7.

[0043] Example 6

[0044] Based on Example 5, the structure is as follows Figure 5 and Figure 6 As shown, the marking device 6 includes a front-to-back position adjustment rod 61, a height adjustment rod 62, and a left-to-right position adjustment rod 69. The axis of the front-to-back position adjustment rod 61 is perpendicular to the axis of the hexagonal bar workpiece 8, the axis of the left-to-right position adjustment rod 69 is parallel to the axis of the hexagonal bar workpiece 8, the axis of the height adjustment rod 62 is perpendicular to the axis of the hexagonal bar workpiece 8, and the axis of the height adjustment rod 62 is perpendicular to the axis of the front-to-back position adjustment rod 61.

[0045] A first strip hole 611 is provided on the side wall of the front and rear position adjustment rod 61 along its axial direction. The first strip hole 611 is connected to the side wall of the guide device body 11 through the marking device connecting screw 5. That is, the screw end of the connecting screw 5 passes through the first strip hole 611 and is threadedly connected to the side wall of the guide device body 11. The guide device body 11 and the nut of the connecting screw 5 are located on both sides of the front and rear position adjustment rod 61. Therefore, the front and rear position adjustment rod 61 is fixed by tightening the connecting screw 5. By loosening the connecting screw 5, the relative position of the first strip hole 611 and the connecting screw 5 is adjusted to adjust the position of the front and rear position adjustment rod 61.

[0046] A third strip hole 691 is provided on the side wall of the left and right position adjustment rod 69 along its axial direction. The end of the front and rear position adjustment rod 61 on the same side as the notch 13 is connected to the third strip hole 691 by a first connecting screw 63. That is, the screw end of the first connecting screw 63 passes through the third strip hole 691 and is threadedly connected to the end of the front and rear position adjustment rod 61. The end of the front and rear position adjustment rod 61 and the nut of the first connecting screw 63 are located on both sides of the front and rear position adjustment rod 61. Therefore, the left and right position adjustment rod 69 is fixed by tightening the first connecting screw 63. By loosening the first connecting screw 63, the relative position of the third strip hole 691 and the first connecting screw 63 is adjusted to adjust the position of the left and right position adjustment rod 69.

[0047] A second strip hole 621 is provided on the side wall of the height adjustment rod 62 along its axial direction. The end of the left and right position adjustment rod 69 on the same side as the hexagonal bar guide device 1 is connected to the second strip hole 621 through the third connecting screw 68. That is, the screw end of the third connecting screw 68 passes through the second strip hole 621 and is threadedly connected to the end of the left and right position adjustment rod 69. The end of the left and right position adjustment rod 69 and the nut of the third connecting screw 68 are located on both sides of the height adjustment rod 62. Therefore, the height adjustment rod 62 is fixed by tightening the third connecting screw 68. By loosening the third connecting screw 68, the relative position of the second strip hole 621 and the third connecting screw 68 is adjusted to adjust the position of the height adjustment rod 62.

[0048] The side wall of the height adjustment rod 62 near the notch 13 is connected to the marking pen holder 67 by the second connecting screw 64. That is, the second connecting screw 64 passes through the height adjustment rod 62 and is threaded to the side wall of the marking pen holder 67. The marking pen holder 67 is provided with a pen hole 672, and a marking pen 65 is inserted into the pen hole 672. The axis of the marking pen 65 is parallel to the axis of the front and rear position adjustment rod 61. The tip of the marking pen 65 is set towards the hexagonal rod guide device 1. The marking pen 65 is used to mark the detected defect location.

[0049] The front and rear position adjustment rod 61 can adjust the distance between the marking pen 65 and the hexagonal bar workpiece 8 through the first strip hole 611. By loosening the second connecting screw 64 and rotating the marking pen holder 67, the marking position of the marking pen 65 on the hexagonal bar workpiece 8 can be adjusted.

[0050] Example 7

[0051] Based on embodiment 6, a third threaded hole 671 is provided on the side wall of the marker pen holder 67. The third threaded hole 671 communicates with the pen hole 672. A marker pen set screw 66 is threadedly connected to the third threaded hole 671. The marker pen set screw 66 is used to limit the position of the marker pen 65. Specifically, by tightening the marker pen set screw 66, the end of the marker pen set screw 66 is pressed against the marker pen 65, thus fixing the position of the marker pen 65. By loosening the marker pen set screw 66, the relative position of the marker pen 65 and the marker pen holder 67 is adjusted.

[0052] The working process of this utility model's hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device is as follows:

[0053] When performing ultrasonic water immersion testing on hexagonal bar workpiece 8, such as Figure 6 As shown, the dovetail protrusion 32 is installed into the dovetail groove 14, thereby connecting the hexagonal bar guide device 1 and the probe mounting bracket 3. The relative positions of the dovetail protrusion 32 and the dovetail groove 14 are adjusted so that the hexagonal bar guide device 1 and the probe mounting bracket 3 are coaxial. The locking screw 2 is then tightened for fixation. The ultrasonic immersion probe 7 is inserted into the probe guide hole 33. The ultrasonic immersion probe 7 is rotated according to the ultrasonic testing process to determine its circumferential position. Simultaneously, the distance between the ultrasonic immersion probe 7 and the hexagonal bar workpiece 8 is adjusted. After adjustment, the probe set screw 4 is tightened to fix the position of the ultrasonic immersion probe 7. The marking pen 65 is fixed in the marking pen holder 67 using the marking pen set screw 66. The marking pen 65 is adjusted so that its axis is perpendicular to the axis of the height adjustment rod 62. The marking pen holder 67 is fixed to the height adjustment rod 62 using the second connecting screw 64. The height adjustment rod 62 is connected to the left and right position adjustment rod 69 via the third connecting screw 68. The left and right position adjustment rod 69 is connected to the first connecting screw at the rear end of the front and rear adjustment rod 61. Screw 63 is connected to the front and rear position adjustment rod 61. Adjust the relative position of the first strip hole 611 and the marking device connecting screw 5 so that the tip of the marking pen 65 is about 20mm away from the hexagonal bar workpiece 8. Tighten the marking device locking screw 5. Loosen the first connecting screw 63 and move the left and right position adjustment rod 69 so that the tip of the marking pen 65 is aligned with the axis of the ultrasonic water immersion probe 7. Tighten the first connecting screw 63. Loosen the third connecting screw 68 and adjust the height adjustment rod 62 so that the tip of the marking pen 65 is flush with the axis of the hexagonal bar workpiece 8. Tighten the third connecting screw 68. Place the trapezoidal groove 16 on the hexagonal bar workpiece 8 and move it along the axis of the hexagonal bar workpiece 8 for ultrasonic water immersion testing. If a defect is found during the test, slightly loosen the marking device locking screw 5 and rotate the front and rear position adjustment rod 61 so that the marking pen 65 is close to the hexagonal bar workpiece 8. Use the marking pen 65 to mark the defect location. After marking, adjust the marking device 6 back to its original position and tighten the marking device locking screw 5 to continue the hexagonal bar testing.

Claims

1. A hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device, characterized in that, It includes a hexagonal bar guide device (1), the top of which is connected to a probe mounting bracket (3), a probe set screw (4) is threaded onto the side wall of the probe mounting bracket (3), and an marking device (6) is connected to the side wall of the hexagonal bar guide device (1).

2. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 1, characterized in that, The hexagonal rod guide device (1) includes a guide device body (11), a dovetail groove (14) is provided on the top of the guide device body (11), the dovetail groove (14) passes through the center point of the upper surface of the guide device body (11), a through hole (12) is provided in the guide device body (11) along its axial direction, the through hole (12) communicates with the dovetail groove (14), a trapezoidal groove (16) is provided on the bottom end face of the guide device body (11), a notch (13) is provided on the side wall of the guide device body (11), the notch (13) communicates with the through hole (12), the dovetail groove (14) is connected to the probe mounting bracket (3), and an marking device (6) is connected to the side wall of the guide device body (11).

3. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 2, characterized in that, The through hole (12) includes a first through hole section (121) and a second through hole section (122). The top end of the first through hole section (121) is connected to the dovetail groove (14), and the bottom end of the first through hole section (121) is connected to the second through hole section (122). The second through hole section (122) is connected to the notch (13). The diameter of the first through hole section (121) is smaller than the top width of the dovetail groove (14), and the diameter of the first through hole section (121) is smaller than the diameter of the second through hole section (122).

4. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 2, characterized in that, The guide device body (11) has a first threaded hole (15) on its side wall. The first threaded hole (15) is connected to the dovetail groove (14). A locking screw (2) is threaded into the first threaded hole (15).

5. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 2, characterized in that, The probe mounting bracket (3) includes a mounting bracket body (31). The bottom of the mounting bracket body (31) is provided with a dovetail protrusion (32), which cooperates with the dovetail groove (14). The top of the mounting bracket body (31) is provided with a probe fixing body (35). The probe fixing body (35), the mounting bracket body (31), and the dovetail protrusion (32) are all coaxially provided with probe guide holes (33), which are connected to the through hole (12).

6. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 5, characterized in that, The probe fixing body (35) has a second threaded hole (34) on its side wall, and the second threaded hole (34) is threaded with a probe set screw (4).

7. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 2, characterized in that, The marking device (6) includes a front-to-back position adjustment rod (61), a height adjustment rod (62), and a left-to-right position adjustment rod (69). A first strip-shaped hole (611) is provided on the side wall of the front-to-back position adjustment rod (61) along its axial direction. The first strip-shaped hole (611) is connected to the side wall of the guide device body (11) via a marking device connecting screw (5). A second strip-shaped hole (621) is provided on the side wall of the height adjustment rod (62) along its axial direction. A third strip-shaped hole (691) is provided on the side wall of the left-to-right position adjustment rod (69) along its axial direction. The end of the front-to-back position adjustment rod (61) on the same side as the notch (13) is connected via a first connecting screw (5). The connecting screw (63) is connected to the third strip hole (691). The end of the left and right position adjustment rod (69) on the same side as the hexagonal bar guide device (1) is connected to the second strip hole (621) through the third connecting screw (68). The side wall of the high and low position adjustment rod (62) near the notch (13) is connected to the marker pen holder (67) through the second connecting screw (64). The marker pen holder (67) is provided with a pen hole (672). A marker pen (65) is inserted into the pen hole (672). The axis of the marker pen (65) is set parallel to the axis of the front and rear position adjustment rod (61). The tip of the marker pen (65) is set towards the hexagonal bar guide device (1).

8. The hexagonal rod manual ultrasonic water immersion detection auxiliary and marking device according to claim 7, characterized in that, The marking pen holder (67) has a third threaded hole (671) on its side wall. The third threaded hole (671) is connected to the pen hole (672). The marking pen set screw (66) is threaded into the third threaded hole (671).

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