JPH0214434Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Fields> The present invention is designed to assemble a type wheel on a drive shaft that rotates in one direction, such as in a printing device of a check writer, so that it can be rotated integrally or rotated in two ways. With regard to a printer in which an arbitrary type character formed on the outer periphery of the type ring is selected at a position facing the printing paper, and the type ring is fixed at the selected position, especially when the type selection cycle ends. This invention relates to improvements to a type wheel stop mechanism that locks the rotation of the type wheel.

<Background Art and its Problems> Conventionally, there is a type wheel stop mechanism disclosed in Japanese Utility Model Application Publication No. 54-4012 which locks the rotation of a type wheel of a printer at the end of a type selection cycle. This stopping mechanism consists of a gear wheel provided integrally with a type wheel on which a plurality of type letters are formed at predetermined intervals in the circumferential direction on the outer circumferential surface, and a gear wheel provided on the outer circumferential surface of the gear wheel at an angle equal to the arrangement pitch of each of the above-mentioned type letters. A type ring locking pawl that is selectively engageable and detachable from a plurality of notches formed with pitches, and the locking pawl fits into a predetermined notch among the respective notches. This locks the rotation of the type wheel. In this way, by locking the type wheel, a predetermined type is selected from among the characters on the type wheel, and this type is held at the printing position.

Incidentally, in each of the cutout portions, the upper surface of the convex portion between adjacent cutout portions is a smooth surface. In this way, if each of the upper surfaces is a smooth surface, if the timing of the locking pawl entering the notch is delayed, the locking pawl will not fit into the predetermined notch. There is a risk that the printed characters may be mistakenly selected because the printed characters are fitted into a notch adjacent to the predetermined notch while slidingly contacting the upper surface of the convex portion.

<Purpose of the invention> Therefore, the present invention has been proposed in view of the conventional situation, and aims to improve the engagement timing of the locking pawl with the type wheel at a predetermined timing to lock the rotation of the type wheel at the end of the type selection cycle. To provide a new printer which enables a shield lock claw to engage with a predetermined position of the type wheel even if the timing is ahead of time or even if it is delayed, thereby accurately selecting type. The purpose is to

<Summary of the invention> In order to achieve the above object, the present invention includes a type ring that is detachably assembled to a drive shaft and has a plurality of type characters formed on the outer periphery at predetermined intervals in the circumferential direction; A gear wheel is integrally assembled with the type wheel and has a plurality of notches corresponding to the above-mentioned type characters formed on the outer periphery at predetermined intervals in the same direction; It has a removable locking pawl, and the upper end edge of the locking portion of the locking pawl in each notch of the gear wheel receives the locking pawl and guides insertion of the locking pawl into the notch. A protrusion for picking up the lock pawl is provided, and a sloped surface for guiding the insertion of the pawl into the notch is provided on a portion of the lock pawl that faces the outer peripheral surface of the gear wheel. It is characterized by:

<Example> Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a longitudinal sectional side view showing an example in which the printer of the present invention is applied to a printing device of an electric check writer. This printer is housed in a case 2 assembled on a base 1. This printer includes a drive shaft 4 connected to the rotating shaft of an electric motor 3 via a speed reduction mechanism (not shown), a plurality of type wheels 5 each rotatably fitted onto the drive shaft 4, and each of these type wheels 5. It has a plurality of gear wheels 6 which are rotatably fitted onto the drive shaft 4 so as to overlap each other in the axial direction. The type ring 5 is molded from synthetic resin, and has sixteen convex portions 5A to 5P formed at equal intervals in the circumferential direction on its outer peripheral surface, as shown in FIG. The surface of the first convex portion 5A has a printed character “0”, the surface of the second convex portion 5B has a printed character “1”, the surface of the third convex portion 5C has a printed character “2”, and a fourth The number "3" is printed on the surface of the fifth protrusion 5D, and the number "4" is printed on the surface of the fifth protrusion 5E.
, "5" is printed on the surface of the sixth protrusion 5F, "6" is printed on the surface of the seventh protrusion 5G, and "7" is printed on the surface of the eighth protrusion 5H. , on the surface of the ninth convex portion 5I, the number “8” is printed, and on the surface of the ninth convex portion 5I, the tenth convex portion 5J
The printed character "9" is engraved on the surface of , and the printed character "¥" or "*" is engraved on the surface of the eleventh convex portion 5K. In addition, the 12th, 13th, 14th, 15th and 16th
The convex portions 5L, 5M, 5N, 5O, and 5P are formed to have a lower height than the other convex portions, and their surfaces are blank portions on which no printed characters are engraved. Further, the gear wheel 6 is also molded from synthetic resin,
On the outer circumferential surface 6a, thirteen notches 6A to 6M are formed in the circumferential direction at equiangular pitches to the arrangement angle pitches of the first to thirteenth convex portions 5A to 5M. The first notch 6A is for the character "0", the second notch 6B is for the character "1", the third notch 6C is for the character "2", and the fourth notch is for the character "2". Part 6D is for the number "3", fifth notch part 6E
is for "4" type, and the sixth notch 6F is for "5"
The seventh notch 6G is for the "6" type, the eighth notch 6H is for the "7" type, the ninth
The notch part 6I is for the printed character "8", the tenth notch part 6J is for the printed character "9", the eleventh notch part 6K is for the printed character "¥" or "*", the twelfth and The thirteenth notches 6L and 6M are for blank parts.

Inside the case 2, a number of elongated locking claws 7 corresponding to the number of each type ring 5 are arranged. Each of these lock pawls 7 is rotatably supported by a support shaft 8 mounted midway in the length direction. The tip 7a of each of the lock claws 7 is L.
It is formed in a downwardly bent shape and is placed facing the outer circumferential surface 6a of each of the gear wheels 6.

Furthermore, a flap type solenoid 10 is attached to the base end 7b of each of the lock pawls 7 via an actuator 9. When a current is supplied to the solenoid 10 and the solenoid 10 is attracted and driven, the actuator 9 rotates around the support shaft 11 in the clockwise direction in FIG. Rotate. By rotating the lock pawl 7, the tip 7a of the pawl 7 is fitted into any one of the notches 6A to 6M.

As shown in FIG. 3, a ratchet pawl 13 is disposed between the type wheel 5 and the gear wheel 6, and its tip 13a engages and disengages from a notch 12 formed on the outer periphery of the drive wheel 4. The ratchet pawl 13 is rotatably supported by a boss portion 14 projecting from the type ring 5. A boss portion 15 projecting toward the gear wheel 6 is formed at the base end of the ratchet pawl 13, and the boss portion 15 is inserted into an engagement hole 16 formed in the gear wheel 6. .
Therefore, the gear wheel 6 is assembled integrally with the type wheel 5. The type ring 5 also has a tip 13a of the ratchet pawl 13.
A leaf spring 17 is attached that always biases the plate in the direction of fitting into the notch 12.

Further, an ink roller 18 is rotatably supported in the case 2 so as to face the outer periphery of each type wheel 5. The ink roller 18 rolls into contact with each type wheel 5 when it rotates (rotation in the direction of arrow A in FIG. 1), so that ink is deposited on each type wheel. It should be noted that the ink roller 18 does not roll into contact with the blank portion of each type wheel 5.

Further, a platen 19 is arranged on the base 2 so as to face the outer periphery of each type ring 5.
The platen 19 is rotatably assembled to one end of a platen support plate 20 rotatably mounted on the base 2, and is attached via the support plate 20 in the direction of arrow B or in the direction of arrow C in FIG. It can be swung freely. The rotating shaft 21 of the platen 19 is connected to the rotating shaft of the drive motor 3 via a link mechanism 22 and the like. When the electric motor 3 drives the platen 19 in the direction of arrow B in FIG. It is held between the above-mentioned type wheels 5, and predetermined characters from each of the above-mentioned type wheels 5 are printed on the printing paper.

Next, one printing cycle of the above printer will be explained. In the following explanation, only the operation of the type wheel 5 for printing the "1 yen" digit of the amount will be explained.

First, by pressing the key button 23 for setting the amount located on the top of the case 2, "1 yen" is set.
Set the digit to "0". As a result, a type selection cycle begins in which the first convex portion 5A for the character "0" is selected from among the convex portions 5A to 5P of the type wheel 5. Then, the print key (START key) 24 arranged on the top surface of the case 2 is pressed to drive the electric motor 3. At this time, the tip 13a of the ratchet pawl 13 is fitted into the notch 12 of the drive wheel 4, and the type wheel 5 is integrated with the drive wheel 4 as shown in FIG. Rotate in the direction of arrow A. When the drive wheel 4 rotates to a position where the tip 7a of the lock pawl 7 faces the first notch 6A, working current is supplied to the solenoid 10, and the lock pawl 7 moves counterclockwise in FIG. The tip 7a of the lock pawl 7 fits into the first notch 6A to lock the rotation of the gear wheel 6, that is, the rotation of the type wheel 5.
As a result, each of the convex portions 5A to 5P of the type ring 5
The convex part 5A of the printed character "0" in the middle is the platen 19
The print character is held at the print position opposite to the print position, and the type selection cycle is completed.

Then, put a ``0'' in the ``1 yen'' digit on the printing paper.
The print cycle begins. The above type selection cycle begins. As the rotation of the drive wheel 4 progresses from the end of the type selection cycle, a pressing force is applied to the gear wheel 6 in a direction opposite to the direction of rotation of the drive wheel 4 (in the direction opposite to arrow A in FIG. 1). In this way, when a pressing force is applied to the gear wheel 6, the boss portion 15 of the ratchet pawl 13 is pressed by one side wall 16A (see FIG. 3) of the engagement hole 16 of the gear wheel 6, and this ratchet The pawl 13 is rotated in the direction of arrow D in FIG. 3 against the elastic force of the leaf spring 17, and the tip 13a of the ratchet pawl 13 separates from the notch 12 and touches the outer peripheral surface of the drive shaft 4. Climb up. In this way, the tip 1 of the ratchet pawl 13
3a rides on the outer circumferential surface of the drive shaft 4, thereby releasing the engagement between the drive shaft 4 and the type wheel 5. As a result, the printing wheel 5 stops at the position where the printing character "0" is selected, and the driving wheel 4
Only the shaft is driven to rotate. When the drive shaft 4 rotates once, a clutch mechanism (not shown) provided between the drive shaft 4 and the rotation shaft of the electric motor 3 is disengaged, so that the drive shaft 4 and the rotation shaft of the electric motor 3 are separated. The connection status of
The rotation of the drive shaft 4 stops.

Then, the platen 19 is connected to the link mechanism 2.
The paper to be printed (not shown) is gradually swung in the direction of arrow B in FIG. The character "0" is printed on the printing paper. As a result, the printing cycle (embossing cycle)
ends. Immediately after printing, the platen 19 further swings in the direction of arrow B in FIG. 1 and is temporarily held at one end of the swing.

Then, when a reset cycle is started in which the type wheel 5 is rotated so that the first convex portion 5A returns to its initial position, when the platen 19 reaches one end of its swing, the clutch mechanism operates to connect. However, when the drive shaft 4 and the rotating shaft of the electric motor 3 are reconnected, the base end 7b of the lock claw 7 is pushed down by the control shaft 25, which moves downward in conjunction with the connecting operation of the clutch mechanism, and the lock is locked. The claw 7 is rotated clockwise in FIG. By the rotation of the lock claw 7,
The tip 7a of this lock pawl 7 is located at the first end of the gear wheel 6.
The type wheel 5 is released from the notch 6A, and the type ring 5 is released from the locked state.

Then, when the drive wheel 4 rotates again and the notch 12 of the drive shaft 4 and the tip 13a of the ratchet pawl 13 fit together, the type wheel 5
rotates again in the direction of arrow A in FIG. 1 together with the drive wheel 4, and the type wheel 5 returns to the initial position shown in FIG. This completes the reset cycle. At the same time as the type wheel 5 returns to the initial position, the platen 19 swings in the direction of arrow C in FIG. 1 via the link mechanism 22 and the like, and returns to the initial position held at the other end of swing.
At this time, since the portion of the type wheel 5 facing the platen 19 is the thirteenth convex portion 5M, that is, a blank portion, the platen 19 does not come into contact with the thirteenth convex portion 5M of the type wheel 5. It can swing smoothly.

By the way, each of the notches 6A to 6 of the gear wheel 6
M and the tip 7a of the lock pawl 7 are formed as shown in FIG. In addition, each of the above notches 6
Since the configurations of A to 6M are the same, only the first notch 6A will be described in the following description. That is, the notch 6A has a concave shape with a rectangular cross section in which the depth D is slightly larger than the width _W1 . A locking surface 60 that locks the tip 7a of the lock pawl 7 in the notch 6A is formed on the radial line of the gear wheel 6, and one side surface 30A is formed on the upper edge of the locking surface 60. The locking surface 60
protrusion 3 for picking up the locking claw that is flush with the
0 is set. Therefore, the locking surface 6
The height H of the surface formed by the locking surface 60 and the one side surface 30A of the protrusion 30 that follows the locking surface 60 is greater than the depth D of the notch 6A. By providing the protrusion 30, even if the timing at which the tip 7a of the lock pawl 7 fits into the notch 6A is delayed at the end of the type selection cycle, the tip 7a remains in the protrusion as shown in FIG. It is received by one side 30A of 30 and guided to be inserted into the notch 6A. Therefore, the tip 7a of the lock claw 7 can be reliably fitted into the notch 6A, and the character "0" can be selected accurately.

Further, an inclined surface 31 is formed at a portion of the tip 7a of the lock pawl 7 that faces the outer circumferential surface 6a of the gear wheel 6. By providing the inclined surface 31, even if the tip 7a of the lock pawl 7 fits into the notch 6A earlier at the end of the type selection cycle, the tip 7a will not get caught on the outer circumferential surface 6a. As shown in FIG. 6, the inclined surface 31 slides on the outer circumferential surface 6a, thereby guiding the insertion into the notch 6A. Therefore, the tip 7a of the lock claw 7
can be reliably fitted into the notch 6A, and the character "0" can be accurately selected.

Furthermore, since the width W ₁ of the notch 6A and the width W ₂ of the tip 7a of the lock pawl 7 are formed to have the same dimension, the tip 7a fits into the notch 6A. The above-mentioned notch 6 of 7a
There is no play against A. Therefore, even if the sliding resistance when the paper to be printed is held between the type wheel 5 and the platen 19 becomes a force that rotates the type wheel 5, the type wheel 5 remains stopped. This makes it possible to obtain a printing condition with no misalignment of type.

Furthermore, the length l of the tip 7a of the lock pawl 7 and the depth D of the notch 6A are formed to have the same dimension. Therefore, the tip 7a of the lock pawl 7 is fitted into the notch 6A without bouncing, and a stable fitted state can be obtained.

<Effects of the invention> As described above, according to the invention, when the engagement timing of the locking pawl that locks the rotation of the type wheel at the end of the type selection cycle with respect to the type wheel is earlier than the predetermined timing, as well as when the timing is delayed. Even in such a case, the lock pawl can be reliably engaged with a predetermined position of the type ring. Therefore,
The selection of type can be made accurately.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional side view of an electronic check writer showing an embodiment of the present invention, Fig. 2 is a side view for explaining the relationship between the type ring and the gear wheel, and Fig. 3 is an enlarged view showing the ratchet pawl. 4 is an enlarged side view for explaining the relationship between the lock pawl and the notch of the gear wheel, and FIG. 5 is a state when the timing of fitting the lock pawl into the notch is delayed. FIG. 6 is an enlarged side view showing the state when the above-mentioned fitting timing is advanced. 4... Drive shaft, 5... Type wheel, 6... Gear wheel,
6A~6M...Notch, 7...Lock claw, 30
... protrusion for picking up the lock claw, 30A ... one side, 31 ... inclined surface, 60 ... locking surface.

Claims (1)

[Scope of utility model registration request] a type wheel which is detachably attached to the drive shaft and has a plurality of type letters formed on its outer periphery at predetermined intervals in the circumferential direction; It has a gear wheel in which a plurality of corresponding notches are formed at predetermined intervals in the same direction, and a lock pawl that can be selectively engaged and disengaged from the notches of the gear wheel, and each of the notches of the gear wheel A protrusion for picking up the lock pawl that receives the lock pawl and guides insertion of the lock pawl into the notch is provided on the upper end edge of the locking portion of the lock pawl in the notch. A printer characterized in that a portion of the pawl facing the outer peripheral surface of the gear wheel is provided with an inclined surface for guiding insertion of the pawl into the notch.