Marking device

Abstract

[Problem] To provide a marking device that can, with a simple structure, be restored reliably and correctly rotate an indicator body one full period. [Solution] Provided is a marking device to be fitted into a recess in a molding die, the marking device being characterized by comprising: a hollow cylindrical body with a first hole in the center of a bottom face thereof; a drive part comprising a first base body provided with a first sawtooth portion around the rim of the first hole in the hollow cylindrical body, a second base body provided with a second sawtooth portion that fits into the first base body, and a first connecting rod securing the second base body and extending through the first hole to a lower portion of the marking device; a first drive-driven part comprising a third base body which is provided with a third sawtooth portion that engages with the first sawtooth portion and the second sawtooth portion and which is provided with a fourth sawtooth portion on the face opposite the face on which the third sawtooth portion is provided; and a second drive-driven part comprising a fourth base body provided with a fifth sawtooth portion that engages with the fourth sawtooth portion, and a second connecting rod connected to said base body and provided with a cylindrically swollen head portion, wherein an indicator body is provided on the upper side of the head portion. [Selected drawing] FIG. 3

Description

Marking device

[0001] The present invention relates to a marking device.

[0002] In an injection molding machine, a movable mold base (movable mold) is driven in a direction to approach or move away from a fixed mold base (fixed mold), and the mold base is clamped (mold closing) and opened (mold opening). Molten synthetic resin is supplied to the cavity in the clamped mold, and the molten synthetic resin hardens to form a molded product.

[0003] When mass-producing products, a marking device is used to stamp the serial number and manufacturing date onto the surface of the product. The serial number and manufacturing date are stamped by inserting a marking device equipped with a marking display into the cavity side of the molding die, and by performing molding with the die inserted, the stamped content is directly stamped onto the surface of the molded product.

[0004] A marking device has been proposed for use in an injection molding machine, which allows an operator to change the marking on an index body without having to work in an awkward position or without being burned by contacting any part of the body with the mold base, and which has excellent heat resistance and durability, a simple structure, and is inexpensive (see, for example, Patent Document 1).The marking device described in Patent Document 1 includes a hollow cylindrical outer shell body on which letters or symbols are engraved circumferentially on the upper end surface, an upper drive / driven mechanism disposed above the hollow portion of the outer shell body, and a lower drive mechanism disposed below the hollow portion of the outer shell body.

[0005] The marking device in Patent Document 1 discloses a configuration in which a connecting rod is driven by air pressure generated in a lower drive mechanism, and a display unit is rotated by the engagement of sawtooth portions provided in an upper drive / driven mechanism with each other and the engagement of the sawtooth portions with protrusions provided on a rotor. This marking device comprises an outer shell body having letters or symbols engraved circumferentially on the upper end surface of a hollow cylindrical body, an upper drive / driven mechanism disposed above the hollow portion of the outer shell body, and a lower drive mechanism disposed below the hollow portion of the outer shell body, and the upper drive / driven mechanism comprises an outer cylinder fixed inside the outer shell body and provided with an engagement portion at its upper end, an inner cylinder loosely fitted within the outer cylinder and also having an engagement portion formed at its upper end, a rotor formed of a solid or hollow cylindrical body loosely fitted within the outer shell body, and a biasing means for biasing the rotor downward. The inner cylinder is connected to a piston via a connecting rod, the rotor and the outer cylinder are engaged in a first state and disengaged in a second state, the rotor and the inner cylinder are disengaged in the first state and engaged in the second state, the lower drive mechanism comprises a cylinder into which compressed air is introduced via an air passage connected to a compressed air source, and the piston is loosely fitted in the cylinder and driven by the compressed air, and the cylinder is fitted into the outer shell.

[0006] This marking device utilizes the engagement and disengagement between the rotor and the sawtooth portion of the outer cylinder, and between the rotor and the sawtooth portion of the inner cylinder, which is out of phase with the sawtooth portion of the outer cylinder, to move the protrusion of the rotor by one pitch and rotate the index body by one period. A vertical slit is provided on the inner surface of the outer cylinder, while a rib is provided on the outer surface of the inner cylinder.

[0007] However, in the marking device of Patent Document 1, a protrusion provided on the bottom of the rotor engages with the sawtooth of the second sawtooth portion of the inner cylinder to rotate the rotor. When returning to its original position, the protrusion engages with the outer cylinder. Therefore, there are cases where the sawtooth portion of the inner cylinder cannot be returned to the correct position simply by moving the inner cylinder up and down. This causes a problem in that the index body cannot be rotated correctly through one cycle.

[0008] Patent No. 7239195

[0009] The present inventors have conducted extensive research to solve the above problems, and have come to the conclusion that they can provide a marking device with a simple structure that can reliably return to its original position and correctly rotate the index body through one cycle.

[0010] A marking device according to a first aspect of the present invention is a marking device that is fitted into a recess of a molding die, the marking device comprising: a hollow cylindrical body having a first hole in the center of its bottom surface; a first base body having a first sawtooth portion provided on the periphery of the first hole inside the hollow cylindrical body; a second base body having a second sawtooth portion provided inside the first base body; and a drive unit that fixes the second base body and extends below the marking device via the first hole; and a first drive / follower unit that includes a third base body having a third sawtooth portion that engages with the first and second sawtooth portions, and a fourth sawtooth portion provided on a surface opposite to the surface on which the third sawtooth portion is provided. The device is characterized by comprising a second driving / following unit having a fourth base body on which a fifth sawtooth portion that engages with the fourth sawtooth portion is provided, and a second connecting rod that is connected to the fourth base body and has a cylindrically enlarged head, and an index body is provided above the head.

[0011] The marking device of claim 2 of the present invention is characterized in that the second driving / following unit further comprises a lid portion provided on the top of the hollow cylinder and having a cylindrical portion with a cylindrically protruding central portion, and a fifth base body on the underside of the lid portion and having a sixth sawtooth portion on its upper surface fixed to the hollow cylinder, the second connecting rod passes through the lid portion and the fifth base body, and the second connecting rod has a seventh sawtooth portion on the underside of its head that engages with the sixth sawtooth portion.

[0012] The marking device of claim 3 of the present invention is characterized in that the first sawtooth portion and the second sawtooth portion are sawtooth portions having the same period, and when the second base body is inserted into the first base body, the sawtooth portions of the first sawtooth portion and the second sawtooth portion are arranged with a shifted period, and the third sawtooth portion is engaged with the first sawtooth portion.

[0013] In the marking device according to a fourth aspect of the present invention, the deviation in the period between the saw teeth of the first saw-tooth portion and the saw teeth of the second saw-tooth portion is 0.1 to 0.9 periods.

[0014] In the marking device according to claim 5 of the present invention, the third saw-tooth portion has one tooth or two teeth.

[0015] In the marking device of claim 6 of the present invention, a first biasing means is provided between the third base body and the fifth base body, and a second biasing means is provided between the fourth base body and the fifth base body.

[0016] In the marking device according to claim 7 of the present invention, the index body is attached to the upper side of the head by using a connecting means.

[0017] In the marking device of claim 1 of the present invention, the sawtooth portion engages with the outer sawtooth of the two teeth that make up the third sawtooth portion. Therefore, when the first connecting rod rises, the second sawtooth portion engages with the inner sawtooth of the two teeth that make up the third sawtooth portion. This ensures that the movement of the first drive unit is transmitted reliably to the first drive / follower unit and the second drive / follower unit, allowing the index body to rotate one graduation reliably with a single operation. When the series of operations is completed, the second base body descends to the lowest surface within the hollow cylinder. At this time, the third base body also descends within the hollow cylinder, and the sawtooth of the first sawtooth portion engages with the outer sawtooth of the two teeth that make up the third sawtooth portion. Because the second base body cannot rotate within the hollow cylinder, the first and second sawtooth portions can be restored to their positional relationship before the start of the operation at the bottom of the hollow cylinder. The two teeth that make up the third sawtooth portion are fixed within the third base. Therefore, the sawtooth of the first sawtooth portion engages with the outermost one of the two teeth that make up the third sawtooth portion, allowing the first sawtooth portion, the second sawtooth portion, and the third sawtooth portion to return to their correct positions. As a result, a marking device can be obtained that has a simple structure, is reliably returned to its original position, and can correctly rotate the index body through one cycle.

[0018] In the marking device of claim 2 of the present invention, the second connecting rod penetrates the cover portion and the fifth base body. A cylindrically enlarged head portion provided on the second connecting rod can move up and down within the cylindrical portion and rotate within the cylindrical portion. The second connecting rod is guarded within the cylindrical portion, so that the second connecting rod can move and rotate reliably. Furthermore, a seventh sawtooth portion that engages with the sixth sawtooth portion is provided below the head portion, and an index body is provided above the head portion, so that the index body can be reliably rotated one cycle with a single operation.

[0019] In the marking device of claim 3 of the present invention, when no force is applied from below to the first connecting rod, the first sawtooth portion and the second sawtooth portion have sawtooth with the same period. Before starting operation, the sawtooth of the first sawtooth portion and the sawtooth of the second sawtooth portion are configured as two teeth with a shifted period. The third sawtooth portion is engaged with the first sawtooth portion when no force is applied from below to the first connecting rod. Therefore, when a single operation is completed, the first sawtooth portion and the third sawtooth portion can be returned to their fully engaged positions. As a result, operation can be performed reliably.

[0020] In the marking device of claim 4 of the present invention, if the deviation in period between the saw teeth of the first saw-tooth portion and the saw teeth of the second saw-tooth portion is 0.1 to 0.9 periods, the first saw-tooth portion and the third saw-tooth portion can be returned to their complete engagement positions.

[0021] In the marking device of claim 5 of the present invention, the third saw-tooth portion may have one tooth or two teeth. If it has one tooth, it has a simple structure and can be manufactured inexpensively. If it has two teeth, the first saw-tooth portion and the third saw-tooth portion can be more reliably engaged with each other, thereby ensuring reliable re-engagement.

[0022] In the marking device of claim 6 of the present invention, a first biasing means is provided between the third base body and the fifth base body, and a second biasing means is provided between the fourth base body and the fifth base body, so that when the sixth sawtooth portion and the seventh sawtooth portion engage with each other, the third base body moves downward and the fourth base body moves upward, returning the marking device to the state it was in before the start of operation.

[0023] In the marking device of claim 7 of the present invention, the index body is attached to the upper side of the head using a connecting means. Since the index body is attached to the head of the second connecting rod using a connecting means, the index body can be replaced depending on the purpose of use.

[0024] FIG. 1 is a cross-sectional view of a marking device according to the present invention attached to a mold substrate. FIG. 2 is a perspective view of the marking device according to the present invention. FIG. 3 is a cross-sectional view of the marking device of FIG. 2 taken along the line A-A'. FIG. 4 is an exploded perspective view of the marking device of FIG. 2. FIG. 5 is a conceptual diagram illustrating the operation of the marking device according to the present invention. FIG. 6 is a conceptual diagram illustrating another operation of the marking device according to the present invention. FIG. 7 is a conceptual diagram illustrating another operation of the marking device according to the present invention. FIG. 8 is a conceptual diagram illustrating another operation of the marking device according to the present invention. FIG. 9 is a conceptual diagram illustrating another operation of the marking device according to the present invention. FIG. 10 is a conceptual diagram illustrating another operation of the marking device according to the present invention.

[0025] An embodiment of the marking device of the present invention will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of the marking device of the present invention attached to a mold substrate. Fig. 2 is a perspective view of the marking device of the present invention, and Fig. 3 is a cross-sectional view of the marking device of Fig. 2 taken along the line A-A'. Fig. 4 is an exploded perspective view of the marking device of Fig. 2.

[0026] The marking device 2 according to the present invention is attached to a mold base plate when in use. As shown in FIG. 1, for example, the top surface of the marking device 2 according to the present invention is tightly fitted into a recess in the mold base plate 1 so that it is flush with the cavity surface. A display plate 28 bearing numbers, letters, etc. is attached to the periphery of the top surface of the marking device 2 in FIG. 2. The mechanism connecting to the lower part of the first connecting rod (9) extending from the bottom surface of the marking device 2 is not shown in FIG. 1. The marking device 2 is driven by moving the first connecting rod (9) in the vertical direction. There are no particular limitations on the driving means for causing the vertical movement, and high-pressure air from a compressed air source or the like may be used to move the marking device in the vertical direction, or an electric motor or the like may be used to move the marking device in the vertical direction. Any known driving means may be used.

[0027] [First embodiment] [Configuration] As shown in Figures 3 and 4, the marking device 2 according to the present invention comprises a hollow cylindrical body 3 having a first hole 4 in the center of its underside, and a driving unit A, a first driving / driven unit B, and a second driving / driven unit C.

[0028] (Drive unit) In the present invention, the drive unit A comprises a first base body 5 having a first sawtooth portion 6 provided on the periphery of a first hole 4 in a hollow cylinder 3, a second base body 7 having a second sawtooth portion 8 provided thereon and fitted inside the first base body 5, and a first connecting rod 9 that fixes the second base body 7 and extends to the bottom of the marking device 2 through the first hole 4.

[0029] The driving unit A serves to drive the first driving / following unit B to move upward and rotate in the axial direction using an upward force of the device applied from the outside to the first connecting rod 9.

[0030] The first base 5 is cylindrical and is fixed to the periphery of the first hole 4 in the hollow cylinder 3. The outer side of the first base 5 contacts the inner surface of the hollow cylinder 3, and the bottom surface is fixed to contact the upper surface of the bottom surface of the hollow cylinder 3. The first sawtooth portion 6 is provided on the upper part of the first base 5.

[0031] The second base 7 is fixed to the first connecting rod 9 and moves vertically as the first connecting rod 9 moves vertically. The first connecting rod 9 is only allowed to move vertically. The second sawtooth portion 8 has sawtooth arranged at the same period as the first sawtooth portion 6. When the second base 7 is fully inserted into the first base 5, the first sawtooth and second sawtooth are arranged with a period offset. The period offset is suitably selected, preferably in the range of 0.1 to 0.9 periods. The sawtooth structure is not particularly limited and may be a single-edged structure or a double-edged structure. In the example of FIG. 3, the sawtooth of the first sawtooth portion 6 has a single-edged structure, and the sawtooth of the second sawtooth portion 8 has a double-edged structure.

[0032] The first connecting rod 9 is provided so as to be coaxial with the hollow cylindrical body 3 .

[0033] (First driving / follower part)

[0034] The first driving / follower unit B moves upward in response to the driving of the driving unit A. The third sawtooth unit 15 provided on the lower part of the third base 10 of the first driving / follower unit B rotates coaxially with the rotation generated by the driving of the driving unit A. The first driving / follower unit B transmits the upward movement and rotation of the first driving / follower unit B to the second driving / follower unit C, thereby driving the second driving / follower unit C.

[0035] The first driving / following unit B includes a third base 10. The third base 10 has a disk-like shape that is coaxial with the hollow cylinder 3. The first driving / following unit B can move up and down within the hollow cylinder 3 and can rotate while remaining coaxial with the hollow cylinder 3. The third base 10 is not connected to a connecting rod.

[0036] The third base 10 is provided with a third sawtooth portion 15 on the second base 7 side, which engages with the first sawtooth portion 6 and the second sawtooth portion 8. The third sawtooth portion 15 is composed of two teeth, one that engages with the sawtooth of the first sawtooth portion 6 and the other that engages with the sawtooth of the second sawtooth portion 8. Of the teeth of the third sawtooth portion 15, the teeth that engage with the sawtooth of the first sawtooth portion 6 and the other that engage with the sawtooth of the second sawtooth portion 8 are arranged so that the third sawtooth portion 15 does not simultaneously engage with the first sawtooth portion 6 and the second sawtooth portion 8. By forming the third sawtooth portion 15 into two teeth in this shape, it is possible to reliably engage with the sawtooth of the first sawtooth portion 6 and the sawtooth of the second sawtooth portion 8. Alternatively, the third sawtooth portion 15 may be a single tooth.

[0037] A fourth sawtooth portion 17 is provided on the surface of the third base 10 opposite to the surface on which the third sawtooth portion 15 is provided.

[0038] (Second driving / follower part) The second driving / follower part C moves upward in response to the driving of the first driving / follower part B, and rotates coaxially with the rotation caused by the driving of the first driving / follower part B, thereby rotating the index body 14.

[0039] The second driving / driven unit C includes a fourth base 11, a fifth base 19, a cover 12, and a second connecting rod 13. The second connecting rod 13 is integral with the fourth base 11. The fifth base 19 and the cover 12 have holes in their centers through which the second connecting rod 13 passes, but they are fixed to the hollow cylindrical body 3 and do not move.

[0040] The fourth base body 11 has a fifth sawtooth portion 20 that engages with the fourth sawtooth portion 17 on the side facing the third base body 10. A fifth base body 19 is provided on the opposite surface of the fourth base body 11. A sixth sawtooth portion 22 is provided on the surface of the fifth base body 19 opposite the fourth base body 11. When no force is applied to the first connecting rod 9 from below, the sawtooth of the fourth sawtooth portion 17 and the sawtooth of the fifth sawtooth portion 20 are positioned so that their opposing surfaces do not fit together.

[0041] The lid portion 12 is provided to cover the entire upper part of the hollow cylindrical body 3. A cylindrical portion 18 that protrudes cylindrically is provided in the center of the lid portion 12. The lid portion 12 supports the vertical movement of the second connecting rod 13 within the cylindrical portion 18. The sixth sawtooth portion 22 is also present within the cylindrical portion 18.

[0042] The second connecting rod 13 fixes the fourth base body 11 coaxially to the hollow cylindrical body 3. The second connecting rod 13 has a cylindrically swollen head portion 21 provided within the cylindrical portion 18. A seventh sawtooth portion 23 that engages with the sixth sawtooth portion 22 is provided below the head portion 21. The second connecting rod 13 moves up and down. In addition, the second connecting rod 13 and the fourth base body 11 can rotate coaxially. The cylindrically swollen head portion 21 of the second connecting rod 13 can move up and down within the cylindrical portion 18 of the lid portion 12.

[0043] An index body 14 is provided at the tip of the head 21. The index body 14 indicates a specific letter or number on a dial on which letters and numbers are written. Specifically, an arrow or the like is attached. The index body 14 may be integrated with the head 21 of the second connecting rod 13 as shown in FIG. 3, or may be attached to the upper side of the head using a connecting means as shown in FIG. 4. A known connecting means such as a screw is used as the connecting means.

[0044] In the marking device 2 of the present invention, a first biasing means 24 is provided between the upper side of the third base body 10 and the lower side of the fifth base body 19, and a second biasing means 25 is provided between the upper side of the fourth base body 11 and the lower side of the fifth base body 19. The biasing means may be any known means, such as a spring.

[0045] [Operation] The operation of the marking device of the present invention will be described below using Figures 5 to 10. In this series of operations, an example in which the third sawtooth portion has two teeth will be described, but the basic operation remains the same even if the third sawtooth portion has one tooth. (Step 1) Figure 5 is a conceptual diagram illustrating the state of the marking device of the present invention before use (Step 1). In Figure 5, the sawtooth of the first sawtooth portion 6 is engaged with the sawtooth of the third sawtooth portion 15. The sawtooth of the second sawtooth portion 8 is not engaged with the sawtooth of the third sawtooth portion 15'. The sawtooth of the second sawtooth portion 8 and the sawtooth of the third sawtooth portion 15' are not engaged and are each positioned with a period offset from the sawtooth of the first sawtooth portion 6. The fourth sawtooth portion 17 and the fifth sawtooth portion 20 are positioned with a period offset from each other. These period offsets are each appropriately selected, preferably in the range of 0.1 to 0.9 periods. The sixth sawtooth portion 22 and the seventh sawtooth portion 23 are engaged with each other.

[0046] (Step 2) Figure 6 is a conceptual diagram illustrating the state in which the driver A begins to drive and begins to apply a force that moves the first connecting rod 9 upward. In Figure 6, as the driver A moves upward, the sawtooth of the first sawtooth portion 6 disengages from the sawtooth of the third sawtooth portion 15. As the driver A moves upward, the sawtooth of the second sawtooth portion 8 abuts against the sawtooth of the third sawtooth portion 15'. When the driver A is moved further upward, the sawtooth of the second sawtooth portion 8 engages with the sawtooth of the third sawtooth portion 15'. This engagement rotates the first driver / follower portion B. This rotation also rotates the third base 10 and the fourth sawtooth portion 17. By this rotation, as shown in FIG. 6, the fourth sawtooth portion 17 moves to a position where the inclined portion 17' of the fourth sawtooth portion 17 and the inclined portion 20' of the fifth sawtooth portion 20 face each other.

[0047] When the third saw-tooth portion 15 has a single tooth, the saw teeth of the third saw-tooth portion 15 are engaged with the saw teeth of the first saw-tooth portion 6 when no force is applied from below to the first connecting rod 9. When force begins to be applied from below to the first connecting rod 9, the first saw-tooth portion 6 and the second saw-tooth portion 8 come into contact with the third saw-tooth portion 15. When further force is applied from below to the first connecting rod 9 and it moves upward, the third saw-tooth portion 15 rotates and engages with the second saw-tooth portion 8. This engagement rotates the first driving / following portion B. The subsequent movement of the first driving / following portion B is the same as in the case of a two-toothed portion.

[0048] (Step 3) Figure 7 is a conceptual diagram illustrating a state in which a force is being applied to move the drive unit A further upward. As shown in Figure 7, when the second connecting rod 13 moves further upward, the slanted portions of the sawtooth teeth of the fourth sawtooth portion 17 come into contact with the slanted portions of the sawtooth teeth of the fifth sawtooth portion 20. At this time, the second connecting rod 13 begins to rise, and the tips of the sawtooth teeth of the sixth sawtooth portion 22 come into contact with the tips of the sawtooth teeth of the seventh sawtooth portion.

[0049] (Step 4) In the state shown in Figure 7, when the first connecting rod 9 of the driving unit A is further moved upward, both the first driving / follower unit B and the second driving / follower unit C continue to rise. At this time, the fourth sawtooth unit 17 and the fifth sawtooth unit 20 rise while being in contact with each other. When the first driving / follower unit B is further raised, the sawtooth of the fifth sawtooth unit 20 slides down the sawtooth of the fourth sawtooth unit 17, as shown in Figure 8. The fourth sawtooth unit 17 and the fifth sawtooth unit 20 have grooves 26 and 27 between their respective sawtooths. The sawtooth of the fourth sawtooth unit 17 and the sawtooth of the fifth sawtooth unit 20 mesh within the grooves 26 and 27. The number of sawtooths in the fourth sawtooth portion 17 and the number of sawtooths in the fifth sawtooth portion 20 are half the number of sawtooths in the third sawtooth portion. Meanwhile, grooves 26, 27 provided between the sawtooths of the fourth sawtooth portion 17 and the fifth sawtooth portion 20 are present on the surfaces of the third base body 10 and the fifth base body 11 in the same number and at equal intervals as the number of sawtooths in the fourth sawtooth portion 17 and the number of sawtooths in the fifth sawtooth portion 20. Therefore, by engaging with the grooves 26, 27, the second connecting rod 13 rotates by half the number of sawtooths in the fifth sawtooth portion 20 (i.e., the number of sawtooths in the third sawtooth portion). These operations cause the second connecting rod 13 to rotate one cycle.

[0050] By performing the operations in steps 3 and 4 above, the seventh sawtooth portion 23 rotates through one cycle. This rotation allows the index body 14 to rotate through one cycle. In order to rotate the index body 14 through one cycle in this manner, the number of sawtooths on the first sawtooth portion 6, the second sawtooth portion 8, the third sawtooth portion 15, the sixth sawtooth portion 22, and the seventh sawtooth portion 23 only needs to be twice the number of sawtooths on the fourth sawtooth portion 17 and the fifth sawtooth portion 20. For example, as shown in FIG. 2 , if the dial is numbered 0 to 9, a single operation is sufficient to rotate the index body 14 36°, so the number of sawtooths on the first sawtooth portion 6, the second sawtooth portion 8, the third sawtooth portion 15, the sixth sawtooth portion 22, and the seventh sawtooth portion 23 only needs to be 10, and the number of sawtooths on the fourth sawtooth portion 17 and the fifth sawtooth portion 20 only needs to be 5.

[0051] (Step 5) Figure 9 is a conceptual diagram illustrating the state in which the force moving the driver A upward is released. When the force moving the first connecting rod 9 upward is released, the driver A moves downward. The force moving the first driver / follower B upward is also released, so it moves downward. As a result, the fourth sawtooth portion 17 and the fifth sawtooth portion 20 are disengaged.

[0052] (Step 6) Figure 10 is a conceptual diagram illustrating the state when the operation is completed. The first connecting rod 9 and the second base body 7 are lowered completely. The second base body 7 is inserted inside the first base body 5. The sawtooth of the third sawtooth portion 15 engages with the sawtooth of the first sawtooth portion 6. This ensures that the first driving / driven part B is rotated and reset, completing the operation.

[0053] To place the index body 14 in the desired position, steps 1 to 6 are repeated.

[0054] In this specification, the deviation between sawtooth portions having the same period may be 0.1 to 0.9 periods, and the deviation in period may be selected appropriately within this range.

[0055] The marking device of the present invention is provided with a first biasing means 24 and a second biasing means 25. The first biasing means 24 is provided between the third base body 10 and the fifth base body 19. The second biasing means 25 is provided between the fourth base body 11 and the fifth base body 19. During the operations shown in Figures 6 to 8, the first biasing means 24 is in an extended state, and the second biasing means 25 is in a compressed state. When the upward force applied to the first connecting rod is released, the first biasing means 24 and the second biasing means 25 return to their original states, causing the fifth sawtooth portion 20 and the fourth sawtooth portion 17 to quickly separate.

[0056] [Second embodiment] In the second embodiment, the driving unit and the first driving / following unit are the same as those in the first embodiment, but the second driving / following unit is different. Only the differences will be described below.

[0057] The second driving / following unit C of the second embodiment includes a fourth base body 11 provided with a fifth sawtooth portion 20 that engages with the fourth sawtooth portion 17, and a second connecting rod 13 that is connected to the base body 11 and has a cylindrically enlarged head portion 21, and an index body 14 is provided above the head portion 21.

[0058] The second embodiment is a simplified version of the first embodiment. In this embodiment, the fifth base 19, the cover 12, the sixth sawtooth portion 22, and the seventh sawtooth portion 23 are not present. An index body 14 is provided at the tip of the head 21 of the second connecting rod 13.

[0059] 4, the fourth sawtooth portion 17 and the fifth sawtooth portion 20 have grooves 26 and 27 formed between the sawtooths, respectively, which allows the index body 14 to rotate by one period.

[0060] (Step 1) and (Step 2) are as described above.

[0061] (Step 3') As the first connecting rod 9 moves further upward, the driving unit A also moves upward. Because the sawtooth of the second sawtooth portion 8 and the sawtooth of the third sawtooth portion 15 are engaged, the first driving / follower unit B also moves upward. When the first driving / follower unit B is moved further upward, the slanted portions of the sawtooth of the fourth sawtooth portion 17 come into contact with the slanted portions of the sawtooth of the fifth sawtooth portion 20. This causes the second connecting rod 13 to move upward.

[0062] (Step 4') When the first connecting rod 9 of the driving unit A is further moved upward, both the first driving / follower unit B and the second driving / follower unit C continue to rise. At this time, the fourth sawtooth unit 17 and the fifth sawtooth unit 20 rise while being in contact with each other. When the first driving / follower unit B is further raised, the fifth sawtooth unit 20 slides down the fourth sawtooth unit 17's slanted portion, and the fourth sawtooth unit 17 and the fifth sawtooth unit 20 each fall into the other's groove and mesh with each other. These operations cause the second connecting rod 13 to rotate one cycle. This also causes the index body to rotate one cycle.

[0063] (Step 5') When the force moving the first connecting rod 9 upward is released, the driving unit A moves downward. The force moving the first driving / following unit B upward is also released, so it moves downward. As a result, the fourth sawtooth portion 17 and the fifth sawtooth portion 20 are disengaged.

[0064] (Step 6') The first connecting rod 9 and the second base body 7 are lowered completely. The second base body 7 is inserted inside the first base body 5. The saw teeth of the third saw tooth portion engage with the saw teeth of the first saw tooth portion. This ensures that the drive unit A is repositioned, completing the operation.

[0065] The present invention makes it possible to reliably change the marking of an index body in a marking device for marking a serial number or a manufacturing date on the surface of a molded product in an injection molding machine.

[0066] REFERENCE SIGNS LIST 1 mold substrate 2 marking device 3 hollow cylinder 4 first hole 5 first base body 6 first sawtooth portion 7 second base body 8 second sawtooth portion 9 first connecting rod 10 third base body 11 fourth base body 12 cover portion 13 second connecting rod 14 index body 15 third sawtooth portion 17 fourth sawtooth portion 18 cylindrical portion 19 fifth base body 20 fifth sawtooth portion 21 head portion 22 sixth sawtooth portion 23 seventh sawtooth portion 24 first biasing means 25 second biasing means 26, 27 groove portion 28 display plate A driving portion B first driving / following portion C second driving / following portion

Claims

1. A marking device to be fitted into a recess of a molding die, said marking device comprising: a hollow cylinder with a first hole in the centre of its underside; a first base body with a first sawtooth portion provided on the periphery of the first hole inside said hollow cylinder; a second base body with a second sawtooth portion provided to be fitted into the first base body; a drive unit comprising a first connecting rod that fixes said second base body and extends below said marking device via said first hole; and a first drive / follower unit comprising a third base body with a third sawtooth portion that engages with said first and second sawtooth portions, and a fourth sawtooth portion provided on the surface opposite to the surface on which said third sawtooth portion is provided. a second driving / following unit including a fourth base body having a fifth sawtooth portion that engages with the fourth sawtooth portion, and a second connecting rod that is connected to the fourth base body and has a cylindrically enlarged head portion, and an index body is provided above the head portion.

2. The marking device described in claim 1, wherein the second driving / driven unit further comprises a lid portion provided on the top of the hollow cylinder and having a cylindrical portion with a cylindrical protruding central portion, and a fifth base body attached to the underside of the lid portion and having a sixth sawtooth portion on its upper surface, which is fixed to the hollow cylinder body; the second connecting rod passes through the lid portion and the fifth base body; and the second connecting rod has a seventh sawtooth portion on the underside of its head that engages with the sixth sawtooth portion.

3. The marking device described in claim 1, characterized in that the first sawtooth portion and the second sawtooth portion are sawtooth portions having the same period, and when the second base body is inserted into the first base body, the sawtooth portions of the first sawtooth portion and the sawtooth portions of the second sawtooth portion are arranged with a shifted period, and the third sawtooth portion is engaged with the first sawtooth portion.

4. The marking device according to claim 3, wherein the difference in period between the sawtooth of the first sawtooth portion and the sawtooth of the second sawtooth portion is 0.1 to 0.9 periods.

5. The marking device according to claim 1, wherein the third sawtooth portion has one tooth or two teeth.

6. The marking device according to claim 1, wherein a first biasing means is provided between said third substrate and said fifth substrate, and a second biasing means is provided between said fourth substrate and said fifth substrate.

7. The marking device according to claim 1, wherein the index body is attached to the upper side of the head by a connecting means.

Images