JPH0646677Y2 - Structure of brush for rotary print head - Google Patents

Description

TECHNICAL FIELD The present invention relates to a structure of a brush for a rotary print head in which a force for holding a slip ring is constant.

2. Description of the Related Art A conventional rotary print head is constructed as shown in FIG. In FIG. 5, an ink tank 2 is provided in a print wheel 1, and the ink in this ink tank 2 passes through a feed tube 3 and a nozzle 4
Is supplied to. The feed tube 3 and the nozzle 4 are connected by a joint tube 5, and the nozzle 4 is arranged through the cylindrical piezo element 6. In such a rotary head, a plurality of nozzles 4 are radially arranged around the print wheel 1, and an orifice 4 ′ of the nozzle 4 is provided so as to face the outer circumference of the print wheel 1.

The print wheel 1 is connected to a pipe 8, and the pipe 8 is rotatably supported by ball bearings 7a and 7b fixed to a frame (not shown). A timing pulley 9 is fixed to the pipe 8,
The pipe 8 is rotated by the motor 11 via the timing pulley 9 and the belt 10 wound around the pulley of the motor 11. A slip ring shaft 13 is connected to the lower end of the pipe 8 via a spring 12. The slip ring shaft 13 is supported by ball bearings 14a and 14b, and the pipe 8
It rotates according to the rotation of. Further, a ring unit 15 in which a slip ring 16 in which lead wires 17a and 17b are soldered to the slip ring shaft 13 is integrated with a resin is mounted,
The brush 18 is brought into contact with the slip ring 16,
Driver circuit via signal lines 19 connected to 18 respectively
20 connected.

This rotary print head sends an electric signal to the piezo element 6 via the brush 18, the slip ring 16, and the lead wires 17a and 17b by the driver circuit 20 while rotating the print wheel 1 by the motor 11, and from the orifice 4a at the printing timing. Ink particles are ejected and printed on the recording paper.

In this conventional rotary printhead, brush 18
As shown in FIG. 6, a terminal piece 18a obtained by punching out a thin metal plate in a comb shape is molded with resin to form a fixing portion 18b, and a connecting portion 18c of the terminal piece 18a is cut off.
19 was connected, and the slip ring 16 was sandwiched between the terminal pieces 18a.

Problems to be Solved by the Invention However, this rotary printhead brush 18
Then, even if one of the terminal pieces 18a is damaged, it is necessary to replace all the brush pieces 18 and reconnect the signal lines 19, which causes a problem that the replacement work is troublesome.
Also, since the terminal piece 18a is only punched out of a thin plate, the clamping force of the terminal piece 18a is not constant, and when the clamping force of the terminal piece 18a is strong, the terminal piece 18a and the slip ring 16 are worn and contact failure occurs. In addition, when the pinching force of the terminal piece 18a is weak from the beginning, there is a problem such as contact failure.

Means for Solving the Problems In order to solve the above problems, the present invention provides a brush piece having a bent portion whose central portion is bent so that the terminal portions face each other, and the bent portion of the brush piece. It is characterized in that it comprises a sandwiching piece for sandwiching, and the bent portion of the brush piece is inserted into a holding portion between the outer flanges of the two divided holders, and is fixed by the sandwiching piece.

In the present invention, the brush pieces which are independent of each other are inserted into the holding portions between the brims of the holder, and the bent portions of the brush pieces are fixed together with the holding portions of the holder by the sandwiching pieces. The clamping force is always constant.

EXAMPLE FIG. 1 is an exploded perspective view of the structure of a slip ring for a rotary print head embodying the present invention. The slip ring shaft 21 has a cross-shaped cross section, and the slip ring shaft 21 has the ball of FIG. A ball bearing 22a corresponding to the bearing 14a is fitted. At this time, the ball bearing 22a is prevented from coming off by the projection 21b of the slip ring shaft 21. Then, a ring 23 is mounted thereon, and a ring holder 24 made of an insulating material such as synthetic resin is further mounted thereon. This ring holder 24 has a collar 24a and a cylindrical portion 24b, and a hold hole 24c is provided at a joint portion of the collar 24a and the cylindrical portion 24b, and a lead wire which is passed through a groove 21a between crosses of the slip ring shaft 21. Hold bare wire 25 'at the end of 25. After inserting the bare wire 25 ′ of the lead wire 25 into the hold hole 24 c of the ring holder 24, the metal ring 26 is fitted into the cylindrical portion 24 b of the ring holder 24. Then, the ring holder 24 holding the bare wire 25 'of the lead wire 25 and the metal ring 26 are sequentially fitted to the slip ring shaft 21, and finally the ball bearing 22b corresponding to the ball bearing 14a of FIG. 5 is fitted. Then, a washer is fitted to the screw end portion 21c of the slip ring shaft 21, and a nut (not shown) is screwed in and fixed.

The rotary printhead slip ring 27 thus constructed has the screw end portion 21c facing downward as shown in FIG. 2 and the spring 12 shown in FIG. 5 at the end portion 21d of the slip ring shaft 21.
Connected to. The ball bearings 22a and 22b of the slip ring 27 are rotatably supported by both ends of a holder 28 which is split in two, and a brush 29 is mounted on a holding portion 28b between the collar 28a of the holder 28.

FIG. 3 is a perspective view of a brush according to an embodiment of the present invention.
Is a bent contact part 29a formed by bending an elongated metal piece, a terminal part 29b that holds the ring 23, and a contact part 29 provided on the bent contact part 29a.
and c and a holding piece 30 for holding the brush 29.

Next, a procedure for mounting the brush 29 on the holder 28 will be described.
First, the brush 29 is placed in the holder 28 as shown in FIG. 4 (a).
Is inserted between the brims 28a so as to sandwich the holding portion 28b. Then, as shown in FIG. 4 (b), the bent portion 29a is attached to the holding portion 28b.
When sandwiched by the sandwiching portion 30, the length of the terminal portion 29b of the brush 29 becomes constant, so that the sandwiching force of the terminal portion 29b becomes constant, and as shown in FIG. The ring 26 can always be clamped with a constant clamping force.

As described above, in this embodiment, the independent brush pieces 29 are inserted into the holding portions 28b between the collars 28a of the holder 28, and the bent portions 29a of the brush pieces 29 are sandwiched together with the holding portions 28b of the holder 28. Since it is fixed, the terminal part 29 of the brush piece 29 is
The holding force of b is always constant, and it is easy to mount, and even if one brush 29 is damaged, only that one needs to be replaced.

As is apparent from the above description, the present invention inserts independent brush pieces into the holding portions between the collars of the holder,
Since the bent portion of the brush piece is fixed by the holding piece of the holder together with the holding portion of the holder, the holding force of the terminal portion 29b of the brush piece is always constant and only one brush needs to be replaced. The advantages are that the structure is simple, the assembly is easy, and the cost is low.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a structure of a slip ring for a rotary print head embodying the present invention, FIG. 2 is a perspective view of a slip ring and a holder of FIG. 1, and FIG. 3 is a brush of one embodiment of the present invention. FIG. 4 is a view showing a state in which the brush is mounted on the holder, FIG. 5 is a sectional view of a conventional rotary print head, and FIG. 6 is a perspective view of the conventional brush. 28 …… holder, 28a …… brim, 29 …… brush, 29a …… bent section, 29b …… terminal section, 29c …… terminal section, 30 …… sandwiching section.

Claims (1)

[Scope of utility model registration request] 1. A plurality of piezo elements provided on a rotatably supported print wheel, a plurality of lead wires for sending an electric signal to each piezo element and arranged in a rotary pipe of the print wheel, and the rotary pipe. The slip ring shaft connected to the slip ring shaft, the bearing supported on the outer circumference of the slip ring shaft, the ring holders with the collar and the cylindrical part that are fitted and fixed on the outer circumference of the slip ring shaft, and the ring holder are fitted to the cylindrical parts respectively. A holder having a plurality of metal rings that are connected to the ends of the lead wires, a holder that fits in the bearing, and that has a plurality of collars and a holding portion that face the collar and the cylindrical portion of the ring holder; The U-shaped piece is provided with bent portions at both ends of the U-shaped piece and is in contact with the peripheral surface of the metal ring. The structure of the brush for the rotary print head, which is composed of a plurality of U-shaped brushes that are fitted to and connected to the signal line, and a gripping part that is fitted to the curved contact part of the brush and that fixes the brush to the holder of the holder.