JPH0228059Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention has a built-in printing unit for changing the date inside the main case, and the printing unit is entirely covered by a decorative case. Regarding the markings, we have improved the mechanism that adjusts the height of the bottom stamp surface of each printing belt of the printing unit. The vertical height position of the unit can be adjusted.

[Conventional technology]

The prior art related to this type of date stamp will be explained with reference to the attached drawings. In the present invention, a printing unit 1 for changing the date is built in a bottomed cylindrical main case 2, and this printing The unit 1 has a plurality of printing belts 11 wound around a base frame 7 in parallel on the left and right between the top and bottom, and each printing belt 1
1 is configured to be rotatable by hand; the printing unit 1 is movable up and down within the main case 2 between the upper stamp surface change position and the lower printing position; The main case 2 has a stopper means for receiving the printing unit 1 at the stamp face changing position, and the printing unit 1 is in the upper stamp face changing position. Sometimes, the operation window 1 for operating the rotary dial 9
5 is formed as an opening in the main case 2; the cylinder bottom wall 16 of the main case 2 has a belt passage hole 17 through which the printing belt 11 enters and exits; and the main case 2 covers the operation window 15 so as to be openable and closable. The cylindrical decorative case 3 is fitted onto the outside of the decorative case 3, and when the decorative case 3 is in the closed position, the height adjustment mechanism 37 that pushes down and holds the printing unit 1 to the printing position against the spring means is attached to the decorative case 3. The basic configuration including the following has been previously proposed by the present applicant (Utility Application No. 116996/1983).

Furthermore, as shown in FIG. 9, the height adjustment mechanism 37 of the printing unit 1 is constructed by screwing an adjustment screw 38 onto the top wall 26 of the decorative case 3, and attaching the lower end of the adjustment screw 38 to the top wall 26 of the printing unit 1. By making contact with the top plate 5 of the base frame 7, the height of the printing unit 1 can be finely adjusted by rotating the adjustment screw 38, so that the lower end printing surface of the printing belt 11 is aligned with the printing surface of the fixed printing body 51. I try to make sure that they are all on the same page. The basic principle of the height adjustment mechanism 37 including the adjustment screw 38 is also known from Japanese Utility Model Application No. 58-39874.

[The problem that the idea aims to solve]

However, the biggest problem with the conventional height adjustment mechanism 37 is that operating the adjustment screw 38 requires a tool such as a screwdriver, or a coin as a substitute thereof. Furthermore, if the operating surface of the adjustment screw 38 is sunk below the top wall 26 of the cosmetic case 3 as shown in FIG. 9, it is difficult to insert a tool substitute such as a coin, making adjustment work difficult.

However, it is possible to integrally provide an operating head that can be rotated by hand at the upper end of the adjustment screw 38, but in that case, the operating head can be arranged so that the operating head almost covers the outer upper surface of the upper wall 26 of the cosmetic case 3. When the entire surface is covered, the adjustment screw 38 moves up and down by rotation, so that the lower surface of the operating head and the upper surface wall 26
An adjustment gap is required between the two, and the operating head protrudes significantly upward, making it rather unsightly. If this adjustment gap is made smaller, processing errors and assembly errors tend to accumulate, causing the operating head to first hit the top wall 26 of the cosmetic case 3, resulting in a situation where the printing unit 1 cannot be pushed down by the required amount. I learned that it would become

In other words, since the adjustment screw 38 including the operation head is screwed into the top wall 26 of the cosmetic case 3, there is a problem in that it moves up and down when rotated.

Therefore, the purpose of this invention is to create a date stamp that allows you to easily adjust the vertical height of the printing unit from outside the cosmetic case by simply rotating the operating head of the adjustment screw with your hand, without using a screwdriver or coin. be.

Another object of the present invention is to provide an appearance in which the operating head of the adjustment screw does not move up and down even when rotated, and thereby allows the vertical height of the printing unit to be reliably adjusted even if there are manufacturing or assembly errors. You are on your way to getting a good date stamp.

[Means to solve the problem]

In the date stamp having the above-mentioned basic configuration, the height adjustment mechanism 37 has a vertically penetrating shape that protrudes downward from the center of the top wall 26 of the cosmetic case 3, as shown in FIGS. 2 and 5. and an adjustment screw 38 rotatably supported on the top wall 26 of the cosmetic case 3; 41, and a short shaft portion 42 protruding downward from the center of the lower surface of the operating head 41.
and a screw shaft 43 protruding downward from the center of the lower surface of the short shaft portion 42, and the short shaft portion 42 and screw shaft 43 of the adjusting screw 38 are fitted into the guide boss 27 from above. In particular, between the inner circumferential surface of the guide boss 27 and the outer circumferential surface of the short shaft portion 42, a circumferential groove 35 is formed on one side, and a circumferential groove 35 is formed on the other side, and the guide boss 27 is fitted into the circumferential groove 35 rotatably but in a manner that prevents it from coming off. The guide is provided with an engaging protrusion 44, and has a threaded cylinder 39 that is screwed onto the threaded shaft 43 of the adjustment screw 38 and whose lower end comes into contact with the top plate 5 of the base frame 7 of the printing unit 1. The upper part of the threaded cylinder 39 is fitted into the boss 27 so as to be vertically movable, and a rotation prevention means is provided between the guide boss 27 and the threaded cylinder 39 to prevent the threaded cylinder 39 from rotating together with the adjustment screw 38. It is a requirement that there be.

[Effect]

To adjust the height of the printing unit 1, the user holds the operating head 41 and rotates the adjusting screw 38 to the right or left. At this time, the entire adjustment screw 38 including the operating head 41 only rotates around the vertical axis and does not move up or down.

The screw tube 39, which is screwed onto the screw shaft 43 that is integrated with the adjustment screw 38, has an upper part that is movable up and down relative to the guide boss 27 on the decorative case 3 side, but is fitted inside in a non-rotating manner. Threaded cylinder 3 with 38 rotations
9 moves up and down without rotating with this. As a result, since the lower end of the threaded tube 39 is in contact with the top plate 5 of the base frame 7 of the printing unit 1, which is urged upward by the spring means, the lower end of the threaded tube 39 is moved up and down. The height of the stamp surface is adjusted to a predetermined height.

[Effect of idea]

According to the present invention, the vertical height of the internal printing unit 1 can be adjusted by directly grasping the operating head 41 of the adjusting screw 38 located on the outer upper surface of the upper wall 26 of the decorative case 3 and rotating it without any tools. The position can be easily adjusted, making it extremely easy to use. At that time, even if the entire adjustment screw 38 is rotated, only the internal threaded cylinder 39 moves up and down, and the adjustment screw 38
Since this itself does not move up and down, the operating head 41 of the adjusting screw 38 can be placed closely on the top wall 26 of the cosmetic case 3 without creating an unnecessary gap, and the shape of the operating head 41 is also decorative. You can make it look good according to Case 3. Since there is no need for the operation head 41 to be sunk below the upper surface wall 26, rotating operation by hand can be easily performed in this respect as well.

Further, the short shaft portion 42 of the adjustment screw 38 is fitted into the guide boss 27 provided on the top wall 26 of the cosmetic case 3 from above, and the guide boss 27 and the short shaft portion 42 are fitted and engaged with each other. Since the circumferential groove 35 and the protrusion 44 are provided, the rotational performance of the adjustment screw 38 relative to the decorative case 3 and the function of preventing it from coming off upwards are ensured by the fitting engagement of these, with a simple configuration and ensuring ease of assembly. This can definitely be achieved.

〔Example〕

FIGS. 1 to 8 illustrate a date stamp according to the present invention, which includes a printing unit 1, a main case 2 that houses it, and a decorative case 3 that is externally fitted onto the main case 2 from above. The main case 2 and the decorative case 3 completely cover the outer surface of the printing unit 1.

In FIG. 3, the printing unit 1 has a base frame 7 which is gate-shaped when viewed from the front and has a top plate 5 and left and right side plates 6, 6.
A plurality of rotary dials 9 (five in the figure) are arranged on the left and right and rotatably supported on this support shaft 8,
A U-shaped plate metal bridge 10 when viewed from the side is installed between the U-shaped notches 6a, 6a at the lower ends of the side plates 6, 6, and an endless rubber printing belt extends between each rotary dial 9 and the bridge 10. 11, and each printing belt 11 can be manually fed and rotated individually using a rotary dial 9.

On the outer peripheral surface of each printing belt 11, character blocks for displaying year, month, day, etc. are arranged at regular intervals. As shown in FIG. 2, a spring receiving plate 12 for receiving a spring member 20, which will be described later, is mounted between the upper ends of the notches 6a, 6a.

The main case 2 is formed as a cylinder with a bottom as a whole, and an operation window 15 for rotating the rotary dial 9 back and forth is formed in the upper half of the cylinder body 14 with a large opening, as shown in FIG. The flange 1 has a rectangular belt passage opening 17 in the cylinder bottom wall 16 through which the printing belt 11 enters and exits, and has a flat end surface 21 for determining the printing direction in the lower half of the cylinder body 14.
8 is a plastic molded product with an overhang.

A printing unit 1 is housed in the main case 2 so as to be vertically movable from above. In FIG. 7, the side plates 6, 6 of the printing unit 1 are located on the left and right inner surfaces of the barrel 14.
The printing unit 1 has a printing position where the lower end of the printing belt 11 protrudes downward from the belt passage opening 17, and the printing belt 11 is rotatable. The guide groove 1
It moves up and down along lines 9 and 19 in a non-rotating manner.

A spring member 20 housed in the main case 1
The printing unit 1 is pushed upward toward the stamp surface changing position, and the printing unit 1 is received by a ring-shaped stopper 22 fixed to the inner surface of the upper end of the cylinder 14. When the rotary dial 9 of the unit 1 is in the state of being received by the stopper 22,
The seal is held at the upper limit of movement, that is, the stamp face changing position.

In FIGS. 2 and 3, the illustrated stopper 22 is fixed to the barrel 14 with a screw 23 screwed into the barrel 14 from the outside surface thereof. This screw 23 also serves as a guide pin for the cosmetic case 3, which will be described later.
The guide head 24 protrudes outside the outer peripheral surface of the barrel 14.

The spring member 20 in the illustrated example is made of a spring plate such as a phosphor bronze plate, and extends from the left and right sides of a flat connecting part 20a by extending the contact legs 20b downward to the left and right outside through a curved part in the middle. It is bent to form an Ω-shape as a whole. Thus, the spring member 20 is entirely housed in the dead space S between the front and rear plate surfaces of the bridge 10, as shown in FIGS.
The lower end of the contact leg 20b protrudes laterally outwardly from below the side opening of the bridge 10, and is received and supported by the cylindrical bottom wall 16 of the main case 2.

The cosmetic case 3 covers the outer surface of the rotary dial 9,
This is for opening and closing the operation window 15 of the main case 2 as necessary.

That is, as shown in FIGS. 3 and 5, the decorative case 3 includes a cylindrical wall 25 which is fitted onto the cylindrical body 14 of the main case 2 in a substantially intimate manner, an upper surface wall 26 continuous to the upper end of the cylindrical wall 25, and an upper surface. It is a plastic molded product having a vertically penetrating guide boss 27 projecting downward from the center of the wall 26, and on the outer peripheral surface of the cylindrical wall 25, there is a stamp direction continuous to the flat end surface 21 of the flange 18 on the front side. A determination surface 28 is formed over the entire length in the vertical direction.

In FIGS. 3 and 7, sliding grooves 30 are formed in the vertical direction at two places on the left and right sides of the opposing inner surface of the cylinder wall 25 to allow the guide head 24 of each fixing screw 23 of the stopper 22 to engage. It has been done. This sliding groove 30 prevents the decorative case 3 from rotating relative to the main case 2, and further prevents the decorative case 3 from slipping upward relative to the main case 2. Specifically, at a position where the lower end of the cosmetic case 3 coincides with the upper edge of the operation window 15, further upward movement is prevented.

Therefore, each sliding groove 30 is not formed all the way to the lower edge of the opening of the cylindrical wall 25. However, in order to guide and engage the guide head 24 of each screw 23 in each sliding groove 30 from below, the guide head 24 of each screw 23 is inserted from the lower half of each sliding groove 30 to the lower edge of the cylindrical wall 25 as shown in FIG. An introduction groove 31 is formed therethrough. This introduction groove 31 consists of a vertical groove 32 that starts from the lower edge of the cylindrical wall 25 and is parallel to the sliding groove 30, and a horizontal groove 33 that bends at a right angle from the vertical groove 32 and connects to the sliding groove 30. When the horizontal groove 33 is slightly shifted upward from the lower end of the sliding groove 30 and the cosmetic case 3 is slid up and down, the guide head 24 may be inadvertently moved from the sliding groove 30 to the introduction groove 31 side. Prevent it from moving.

A circular circumferential groove 35 is formed in the upper inner surface of the guide boss 27, as shown in FIG. As shown in the figure, the hole is formed into a D-shaped cross section with a flat anti-rotation surface 36.

The height adjustment mechanism 37 of the printing unit 1 is composed of the guide boss 27, the adjustment screw 38, and a nut-shaped threaded cylinder 39 that is operated to move up and down with the guide boss 27. It has 37 characteristics.

That is, in FIGS. 4 and 5, the adjustment screw 38 has an operating head 41 having the same diameter as the arc surface at the upper end of the cosmetic case 3, and a short shaft portion 42 that projects downward from the center of the lower surface of the operating head 41. and a small-diameter screw shaft 43 projecting downward from the center of the lower surface of the short shaft portion 42.

The operation head 41 of the adjustment screw 38 is placed in close contact with the outer upper surface of the top wall 26 of the cosmetic case 3, and the short shaft portion 42 and screw shaft 43 are fitted into the guide boss 27 from above. It matches.

A circumferential protrusion 44 is formed on the outer peripheral surface of the short shaft portion 42, and the short shaft portion 42 is connected to the guide boss 27.
By press-fitting the upper part of the operation head 41
The protrusion 44 fits into the circumferential groove 35 while the lower surface is received by the outer upper surface of the upper wall 26, and the adjustment screw 38 is moved upward with respect to the guide boss 27 while being free to rotate only around the vertical axis. We are trying to prevent this from falling out.

The threaded cylinder 39 is formed in a vertically elongated cylindrical shape with an internal thread carved on the inner circumferential surface, and the threaded shaft 4
3 and the upper part is fitted into the guide boss 27.

A flat abutment surface 45 is formed on a part of the outer peripheral surface of the threaded cylinder 39 so as to correspond to the D-shaped cross-section boss hole of the guide boss 27, as shown in FIG. The threaded cylinder 39 is held by the rotation prevention surface 36 of the boss 27 so that it can move vertically but cannot rotate. In other words, the rotation prevention surface 36 and the contact surface 45 constitute a rotation prevention means for restricting the screw cylinder 39 from rotating together with the adjustment screw 38.

When the decorative case 3 is closed as shown in FIG. The base frame 7 is brought into contact with the top plate 5 of the base frame 7, thereby pushing the entire printing unit 1 downward against the elasticity of the spring member 20 to the printing position. In this state, the height of the printing unit 1 is adjusted using the adjusting screw 38 so that the lower end printing surface of the printing belt 11 is located on substantially the same plane as the printing surface of the fixed printing body 51, which will be described later.

2 and 4, in order to hold the cosmetic case 3 in a closed position, there is a circumferential engagement groove 46 near the lower end of the inner surface of the cosmetic case 3, and a flange 18 on the cylindrical body 14 of the main case 2. Minute protrusions 47 that fit into the engagement grooves 46 are formed at the upper portions of the ends.

A fixed print body 51 made of rubber is attached to the lower end of the main case 2 via a print body holder 50. In FIGS. 3 and 5, this print body holder 50
consists of an end wall 52 for pasting the fixed printed body 51 on the lower surface, and an annular regulating wall 53 projecting downward from the circular outer periphery of the end wall 52, and is formed into a dish shape as a whole. 52, there is a rectangular egress window 5 corresponding to the belt passage hole 17 of the main case 2.
It is a plastic molded product with 4 transparent parts.

The fixed printing body 51 has a disk shape, and has a rectangular exit/exit opening 55 in the center of the disk surface through which the printing belt 11 enters and exits.
are opened, and confirmation items such as receipt and reception date, personal name, etc. are printed on both sides of the entrance/exit 55. The fixed printed body 51 has an exit/exit opening 55.
The end wall 52 is aligned with the exit/egress window 54.
The printed body holder 50 is integrated with the printed body holder 50 by being fixedly attached to the printed body holder 50. In this pasted state, the fixed printed body 51
The lower end stamp face slightly protrudes from the lower end of the regulating wall 53, and the stamp face of the fixed print body 51 can be deformed according to the stamping force only within the range of this protrusion amount.

In order to replace or repair the fixed print body 51 and the print body holder 50, the holder 50 is separably fixed to the main case 2 via a mechanical connection means 57.

That is, as shown in FIGS. 3, 5, and 8, the connecting means 57 in the figure is connected to a total of three locations on the upper surface of the end wall 52 of the print body holder 50, one location at the rear center and two locations on the front left and right sides. A coupling protrusion 58 is provided respectively on the cylindrical bottom wall 1 of the main case 2.
By making three connecting holes 59 transparent in 6 and press-fitting the connecting protrusions 58 into the connecting holes 59 from below, the printed body holder 50 is fixed to the main case 2 in a manner that prevents it from coming off but allows it to be removed by force. do. These coupling protrusions 58 and coupling holes 59 are arranged asymmetrically across the egress window 54 and the belt passage hole 17, so that the print body holder 50 can always be positioned in the correct posture without changing the direction of the stamp surface. and can be assembled.

In FIG. 2, the cap 4 that covers the stamp surface of the fixed print body 51 is formed into a cylindrical shape with a bottom, and a sponge-like ink storage mat 60 is laid on the inner bottom of the cap 4. When the cap 4 is fitted onto the lower end of the main case 2, the stamp surface of the fixed print body 51 and the lower end stamp surface of the printing belt 11 each contact the ink storage mat 60, and ink adheres to each stamp surface in preparation for next use. do. In order to hold the cap 4 in this state, minute protrusions 61 and 62 are formed on the upper inner surface of the cap 4 and on the circumferential surface of the barrel 14 near the flange 18, respectively, to prevent the cap from falling off, as shown in FIG. There is.

When not in use, the outer surface of the main case 2 is completely covered with the decorative case 3 and cap 4, leaving the flange 18, as shown in Fig. 2, to prevent dust from adhering to the stamp surface and conversely to prevent ink remaining on the stamp surface. It completely prevents it from sticking to other objects, making it convenient to carry and store. When stamping, the seal can be stamped simply by pulling out the cap 4 as shown in Figure 1.

When it is desired to change the date, as shown in FIGS. 4 and 5, the cosmetic case 3 is pulled up from the main case 2, the operation window 15 is opened, and the rotary dial 9 is exposed to the outside. At this time, the printing unit 1 is pushed by the spring member 20 and automatically moves upward from the printing position shown in FIG. 2 to the stamp surface changing position. Next, the whole body is turned over, and the rotary dial 9 is rotated while looking at the lower end of the printing belt 11 through the exit/exit opening 55, exit/exit window 54, and belt pass-through opening 17, and the necessary date numerals are selected. After that, when the decorative case 3 is closed and fixed to the main case 2, the printing unit 1
is lowered to the original printing position against the spring member 20, and becomes ready for printing.

If the fixed printing body 51 and the printing belt 11 are not flush due to different print densities, directly grasp the operating head 41 of the adjustment screw 38 with your hand and remove the adjustment screw 38.
is rotated to the right or left to move the entire printing unit 1 up and down, and adjust the heights of the stamp surface of the fixed print body 51 and the lower end stamp surface of each printing belt 11 to be flush with each other. At this time, the entire adjustment screw 38 only rotates around the vertical axis without moving up or down. On the other hand, the threaded cylinder 39 that is threaded onto the threaded shaft 43 of the adjustment screw 38 is fitted inside the guide boss 27 in a non-rotating manner, so that only the screw body 39 moves up and down when the adjustment screw 38 rotates. do. Thus, the screw tube 39
When it moves up and down, the lower end of the screw tube 39 comes into contact with the top plate 5 of the base frame 7 of the printing unit 1, so that the overall vertical height position of the printing unit 1 can be adjusted. Therefore, problems caused by the vertical movement of the adjustment screw 38, which have been a problem in the past, can be eliminated.

In addition, an operating head 41 having the same diameter as the arc surface of the decorative case 3 is exposed at the upper end of the decorative case 3, and the height can be adjusted by directly operating the screwdriver with fingers, so it is especially convenient to use tools. You can instantly adjust the height by hand when necessary. Even if the lower surface of the operating head 41 is received in a neat and intimate manner on the outer upper surface of the upper wall 26 of the cosmetic case 3, no hindrance is caused to the rotation of the adjusting screw 38 by the operating head 41.

[Another example]

In addition to the above, the adjustment screw 3 for the cosmetic case 3
8, a circumferential groove 35 is formed on the short shaft portion 42 side of the adjusting screw 38, and protrusions 44 that fit into the circumferential groove 35 are formed at several locations on the inner edge of the opening of the guide boss 27. Good too.

In addition, the peripheral surface of the operating head 41 of the adjusting screw 38 is knurled to form an anti-slip groove, and the operating head 41 is equipped with a semicircular operating knob that can be raised and lowered freely, so that the knob can be operated when not in use. head 4
It is expected that modifications will be made, such as making it possible to self-maintain the state within the outline of 1 by fitting and engaging.

[Brief explanation of the drawing]

1 to 8 show examples of date stamps according to the present invention, and FIG. 1 is a perspective view of the overall appearance;
Figure 2 is an overall vertical sectional front view, Figure 3 is an exploded perspective view, Figure 4 is a schematic vertical sectional front view when the stamp face is changed, and Figure 5
The figure is a vertical side view of the state shown in Fig. 4, and Fig. 6 is a longitudinal side view of the state shown in Fig. 5.
7 is a sectional view taken along line BB in FIG. 5, and FIG. 8 is a sectional view taken along line A-A in FIG. 5.
-C line sectional view. FIG. 9 is a longitudinal side view showing the schematic structure of a previously proposed date stamp cited as a comparative example of the present invention. 1... Printing unit, 2... Main case, 3...
Cosmetic case, 4...Cap, 5...Top plate of base frame, 6...Side plate of base frame, 7...Base frame, 8...Spindle, 9...Rotary dial, 10...Bridge, 1
1...Printing belt, 15...Operation window, 16...Cylinder bottom wall of main case, 17...Belt passage opening, 20...
... Spring member, 22 ... Stopper, 26 ... Top wall of cosmetic case, 27 ... Guide boss, 35 ...
Circumferential groove, 36... Rotating surface, 37... Height adjustment mechanism, 38... Adjustment screw, 39... Threaded tube, 41
. . . Operation head of the adjustment screw, 42 . . . Short shaft portion of the adjustment screw, 43 .

Claims (1)

[Claims for Utility Model Registration] A printing unit 1 for changing the date is built into the main case 2 which is a cylinder with a bottom. Wrap them in parallel on the left and right between the top and bottom, and rotate each printing belt 1 using the rotary dial 9.
1 is configured to be rotatable by hand, and within the main case 2, the printing unit 1 is vertically movable between an upper stamp surface change position and a lower printing position; The main case 2 has a stopper means for receiving the printing unit 1 at the stamp face changing position, and when the printing unit 1 is in the upper stamp face changing position, , operation window 1 for operating the rotary dial 9
5 has an opening formed in the main case 2, has a belt passage hole 17 in the cylinder bottom wall 16 of the main case 2 through which the printing belt 11 goes in and out, and a cylinder in the main case 2 that covers the operation window 15 so as to be openable and closable. A decorative case 3 of the shape of the shape is attached to the outside, and a height adjustment mechanism 37 is attached to the decorative case 3 to push down and hold the printing unit 1 to the printing position against the spring means when the cosmetic case 3 is in the closed position. In the date stamp shown in FIG. The adjusting screw 38 includes an operating head 41 located on the outer upper surface of the upper wall 26 of the decorative case 3, and a short shaft portion protruding downward from the center of the lower surface of the operating head 41. 42
and a screw shaft 43 protruding downward from the center of the lower surface of the short shaft portion 42, and the short shaft portion 42 and screw shaft 43 of the adjustment screw 38 are fitted into the guide boss 27 from above, Between the inner circumferential surface of the guide boss 27 and the outer circumferential surface of the short shaft portion 42, a circumferential groove 35 is formed on one side, and a circumferential groove 35 is formed on the other side, and the circumferential groove 35 is fitted into the circumferential groove 35 so as to be rotatable but not slip out. The guide boss 27 is provided with a projection 44 that is screwed into the screw shaft 43 of the adjustment screw 38 and has a screw cylinder 39 whose lower end comes into contact with the top plate 5 of the base frame 7 of the printing unit 1. The upper part of the threaded cylinder 39 is fitted inside the threaded cylinder 39 so as to be able to move vertically, and a rotation preventing means is provided between the guide boss 27 and the threaded cylinder 39 to prevent the threaded cylinder 39 from rotating together with the adjustment screw 38. Features a date stamp.