JPH0131486Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stopper structure for a print lever in an impact type print head. It is conventionally known to provide a stopper with a screw structure to adjustably determine the rest position of a printing hammer or printing lever, as disclosed in, for example, Japanese Patent Laid-Open No. 14017/1983. When adopting such a stopper structure, the movable side whose rest position is regulated by the stopper must be designed so that the metal parts come into contact with the stopper in consideration of wear in the event of a collision. In this case, depending on the structure, this may be a design constraint, and the number of parts may increase, making the structure complex. Therefore, in the present invention, when fixing the moving coil to the printing lever, the bottomed cylindrical bobbin with an opening at the rear end, around which the moving coil is wound, is fixed to the printing lever from the opening side using a metal locking pin. The object of this invention is to simplify the structure by making the locking pin also serve as a part that comes into contact with the stopper. One embodiment will be described with reference to the drawings.
In FIGS. 1 and 2, a support frame 1 has an L-shaped cross section, and its vertically bent portion 2 is mounted on a carriage (not shown). As is well known, the carriage is scanned over almost its entire width in a direction perpendicular to the direction in which the recording medium 3 is fed. A printing hammer device 4 having the following structure is installed on the front side of the support frame 1. The printing hammer device 4 is composed of a printing lever 5 and a leaf spring 6 connected to the lower end of the printing lever 5.
is fixed to the plate 7, which is a supporting member, via caulking pins 8, 8. The printing lever 5 is formed of a plate material, and gradually becomes thinner toward the tip, and a bar-shaped striking portion 9 is integrally formed at the end thereof to protrude. Print lever 5
are connected in the following structure so that their plate surfaces (side surfaces) are perpendicular to the surface of the leaf spring 6.
That is, as clearly shown in FIG.
has an inclined surface 1 that slopes diagonally downward at its lower end.
0 and 11, and a protrusion 12 with a rectangular cross section protrudes forward between both inclined surfaces. The leaf spring 6 is
A rectangular protrusion 13 corresponding to the protrusion 12 is formed,
U-shaped notches 14 and 15 are formed at the upper and lower sides, respectively. Further, two spring legs 17, 17 are formed by a window hole 16 formed between the hole 12 and the notch 15. Furthermore, holes 18, 18 are formed in the lower part of the leaf spring 6, through which the pins 8, 8 can be inserted. The projection 12 is fitted into the hole 13, and at this time the inclined surfaces 10 and 11 abut against the back surface of the leaf spring 6. While being held in this state, the printing lever 5 is connected to the leaf spring 6 by caulking or adhesive means. Therefore, since the printing lever 5 can be displaced in the direction of its plate surface via the leaf spring 6, even if the printing lever 5 is made of a relatively thin plate in order to reduce its weight, it has sufficient rigidity in the direction of displacement. The printing force can be transmitted reliably. In addition to mounting holes 19, 19 for connecting the pins 8, 8, the plate 7 is provided with a vertically long holding groove 20 and a triangular cutout window 21, respectively. The holding groove 20 is located between the mounting holes 19 and 19 when the print lever 5
is formed on the extension line of the cutout window 21, and its lower end
is connected to. A block-shaped receiving member 22 disposed below the printing lever 5 can be slidably inserted into the holding groove 20.
The receiving member 22 has a V-shaped support surface 23 on its upper surface, and the rounded lower end of the printing lever 5 can be rotatably received on this support surface. Further, the receiving member 22 has a round groove 24 on its lower surface, and when the wire spring 25 is applied to this round groove 24, the receiving member 22 is inserted into the holding groove 20.
At that time, both ends of the wire spring 25 are engaged with the side surfaces of the cutout window 21 as shown in the first figure. Therefore, during the assembly shown in FIGS. 1 and 2, the receiving member 22 receives an upward biasing force due to the spring force of the wire spring 25, and a clearance is created between the lower end of the printing lever 5 and the supporting surface 25. It will be incorporated in a completely intimate state without any formation. Thereafter, the receiving member 22 may be fixed to the plate 7 using an adhesive. In such a case, the wire spring 25 may be removed after adhesion, or it may be possible to assemble from the beginning without using the wire spring 25. Further, a bobbin 27 having a movable coil 26 wound thereon is attached to the intermediate portion of the print lever 5 via a metal locking pin 28. Locking pin 28
The bobbin 27 has a collar portion 30 having a larger diameter than the center hole 29 of the bobbin 27 at the rear thereof, so that the printing lever 5 can be inserted into the bobbin 27 by inserting the locking pin 28 from its inner bottom. back side and brim part 30
It is designed to be able to be held between the two. This locking pin 28 is provided with a slot 31 bored in the longitudinal direction at its front part, and both sides of the printing lever 5 are clamped to this slot 31. As shown in FIGS. 1 and 2, the printing hammer device 4 configured as described above has its plate 7 removably fixed to the support frame 1 with a spacer plate 32 interposed therebetween via screws 33. has been done. The spacer plate 32 is fixed to the support frame 1 via pins 34, 34.
are in contact with both sides of the plate 7 and also function as positioning parts for the printing hammer device 4. Next, the magnetic flux generating device 35 disposed on the back side of the support frame 1 in order to drive the movable coil 26 will be explained. and a permanent magnet 38.
A flange 39 is integrally formed at the rear of the center yoke 37, and a permanent magnet 38 is held between the outer yoke 37 and the flange 39 in a sandwich-like manner.
and are mutually bonded via adhesive. This magnetic flux generating device 35 is connected to the screw 4 shown in FIG.
The movable coil 26 is removably fixed to the support frame 1 via wires 0 and 40, and is located in an annular magnetic path gap formed between the center yoke 36 and the outer yoke 37. Therefore, when a driving current is applied to the moving coil 26, the moving coil 26 magnetically interacts with the magnetic flux in the magnetic path gap that is generated across it, and according to Fleming's law, the magnetic flux shown in FIG. Can operate to the left. A stopper shaft 42 is slidably fitted into a through hole 41 at the center of the center yoke 36 , and a threaded portion 43 at the rear thereof is screwed into a screw hole 44 at the rear of the through hole 41 . The front end surface of the stopper shaft 42 comes into contact with the rear surface of the pin 28 to determine the rest position of the printing lever 5 (printing hammer device 4). This rest position is located slightly forward of the natural position of the printing hammer device 4 and is set to bend the leaf spring 6 forward, so that a bias force acts on the printing hammer device 4 rearward. ing. and,
The angle of inclination of the inclined surfaces 10 and 11 at the lower end of the print lever 5 is designed to be similar to the angle of deflection of the leaf spring 6 at this time. In FIG. 2, a platen 45 is installed to face the printing hammer device 4, and this platen 45 has a length sufficient to cover almost the entire width of the recording medium 3, and has a plurality of A protrusion 46 is formed to protrude substantially parallel to the axial direction. The platen 45 is configured to be driven to rotate continuously in a clockwise direction, so that each of the protrusions 46 can face the striking portion 9 of the printing lever 5 in a crosswise manner in front thereof. A dot can be formed at the intersection of the two. That is, as a result of the rotation of the platen 45, the protrusion 46
can change the cross position in the row (longitudinal direction) with respect to the striking part 9, and as a result of the head scanning carried out in parallel with the rotation of the platen 45, the striking part 9 can change its cross position relative to the corresponding projection 46. The intersection position can be changed in the column (horizontal) direction. Rotation of the platen 45 and scanning of the head are simultaneously performed in parallel, and a drive current is selectively applied to the movable coil 26 at the same time, thereby displaying desired characters, numbers, symbols, figures, images, etc. Formed in dot matrix. In this printing operation, the printing lever 5 rotates about the support surface 23 of the receiving member 22, and the striking part 9 pushes the recording medium 3 and the ink ribbon 47 against the protrusion 46.
, and a dot is formed on the recording medium 3 at the collision (intersection) position of the striking portion 9 and the protrusion 46 . According to the structure of the present invention, when fixing the movable coil to the printing lever, the bottomed cylindrical bobbin with the opening at the rear end, around which the moving coil is wound, is connected to the printing lever from the opening side using the metal locking pin. While adopting a structure in which the locking pin is fixed to the stopper, this locking pin also functions as a part that comes into contact with the stopper, so even in the moving coil method, the rest position can be regulated using a screw type stopper with a small number of parts. The practical effects are significant, such as guaranteeing durability.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention,
FIG. 1 is a front view thereof, FIG. 2 is a right side view partially cut away, and FIG. 3 is an exploded perspective view of a printing hammer device, a movable coil, etc. 5... Printing lever, 6... Leaf spring, 26... Moving coil, 27... Bobbin, 28... Locking pin, 3
5... Magnetic flux generator, 36... Center yoke, 37
... Outer yoke, 38 ... Permanent magnet, 41 ... Through hole, 42 ... Stopper, 43 ... Threaded portion.

Claims (1)

[Claims for Utility Model Registration] A printing lever supported in a cantilevered manner via a leaf spring, a cylindrical moving coil attached to this printing lever, and a magnetic flux crossing this moving coil to generate the printing lever. In a moving coil type printing head, the shape of the bobbin around which the moving coil is wound is:
The magnetic flux generating device has a bottomed cylindrical shape with a rear end opening into which the central yoke can enter, and a metal locking pin is inserted from the rear end opening side to fix the bobbin to the printing lever. A stopper structure for a print lever, characterized in that the head of the stop pin is in contact with the tip of a stopper which is screwed through the center yoke so that it can move forward and backward from behind.