JPS647876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention This invention relates to a print head holding mechanism for a printing device.

TECHNICAL BACKGROUND OF THE INVENTION AND PROBLEMS THEREOF In a printing device, the means for moving a carrier holding a printing head along a platen generally includes fixing a portion of a belt driven by a motor to the carrier using a belt holder. Further, the print head is fixed to the carrier by screws or a clamp mechanism. However, since these clamp mechanisms and belt holders are individually assembled to the carrier, there are many parts to be attached, which complicates the assembly work accordingly.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a printing head holding mechanism for a printing device that can be easily assembled with a reduced number of parts.

SUMMARY OF THE INVENTION This invention includes a pair of left and right head clamps attached to the carrier, the printing head being fixed to the carrier by these head clamps, and a belt holder for fixing a part of the belt for driving the carrier to the carrier. A part of the belt holder is used to support the head clamp, so that the head clamp can be easily assembled by reducing the number of assembly parts.

Embodiment of the Invention An embodiment of the invention will be described with reference to FIGS. 1 to 3. A carrier 3 is slidably held on a carrier shaft 2 parallel to a platen 1. A mounting surface 4 on which a ribbon cassette (not shown) is mounted is formed on the upper surface of the carrier 3, and cassette clamps 5 for mounting the ribbon cassette are attached to both sides of this mounting surface 4. A ribbon drive shaft 6 is attached to the mounting surface 4 so as to be rotatable and elastically movable up and down. Further, on the lower surface of the mounting surface 4, a ribbon drive mechanism 8 is provided which has a pulley 7 and a plurality of gears and transmits rotation of the pulley 7 in one direction to the ribbon drive shaft 6. The wire 9 wound around the pulley 7 is pulled out to both sides and fixed to a pair of left and right frames (not shown). Further, a cover 10 that covers the ribbon drive mechanism 8 is attached to the lower surface of the carrier 3.

Next, the print head 11 is installed at the front of the carrier 3.
Mounting surfaces 13 that support mounting flanges 12 provided on both sides of the mounting surface 13 and a belt receiver 14 that connects these mounting surfaces 13 are formed. A pin-shaped projection 16 for positioning is formed on the mounting surface 13 and is fitted into a hole 15 formed in the mounting flange 12 .
The tops of these protrusions 16 are formed into a round dome shape, and a slope 17 is formed inside the top that slopes outward as it goes upward. Furthermore, U-shaped bearing portions 18 that are open downward are formed on both walls of the mounting surface 13 in the front and rear directions. A pair of left and right head clamps 19 are provided. These head clamps 19 include a hinge shaft portion 20 whose both ends are held by the bearing portion 18, and a pressing portion 21 formed of a projection that presses the mounting flange 12.
and a protrusion 22 that comes into contact with the slope 17 of the protrusion 16;
A knob 23 is integrally formed.

Next, a belt presser 24 is provided. The belt presser 24 includes a mounting piece 26 that is attached to the upper surface of the belt receiver 14 with a screw 25;
A holding piece 28 that holds a part of the timing belt 27, which is a belt, in an engaged state, and a receiving part 29 that extends to both sides and supports small diameter parts at both ends of the hinge shaft part 20 are integrally formed. These receiving portions 29 are formed with stoppers 30 that limit the rotation angle of the head clamp 19 in the releasing direction within a certain range.

In such a configuration, the head clamp 19
Insert the hinge shaft part 20 of the bearing part 18 from the lower open side, and attach the mounting piece 26 of the belt presser 24 to the screw
fix it to the top surface of the head holder 14 and attach it to the belt holder 1.
The timing belt 27 is held between the lower surface of the timing belt 4 and the holding piece 28. At this time, head clamp 19
The hinge shaft portion 20 is supported by the receiving portion 29 and will not fall downward. Therefore, the assembly of the head clamp 19 is easy without increasing the number of parts to be attached. To install the print head 11, first, the mounting flange 12 is placed on the mounting surface 13, and the projections 16 and holes 15 are fitted to position the print head 11. Since the opening angle of the installed head clamp 19 is limited by the stopper 30, the left and right head clamps 1 can be opened with the thumb of one hand and the fingers of the other hand.
You can easily pull the knob 23 of 9 inward,
As a result, the pressing portion 21 of each head clamp 19 presses the mounting flange 12 of the print head 11, and the protrusion 22 engages with the slope 17 of the protrusion 16 of the carrier 3, so that the head clamp 19 is maintained in the clamped state. . When removing the printing head 11, the head clamp 19 is opened outward using a force greater than the engagement force between the projections 16 and 22.

As shown in FIG. 4, by screwing the tip of the screw 25 passed through the mounting piece 26, the belt receiver 14, and the timing belt 27 into the holding piece 28, the timing belt 27 can be attached to the belt receiver 14 and the holding piece. 28 can be firmly tightened.
As shown in FIG. 5, a nut 3 is attached to the tip of the screw 25.
A similar effect can be obtained by tightening 1. Note that the belt presser 24 is made of elastic synthetic resin.

Effects of the Invention Since the present invention is constructed as described above, the hinge shaft portion of the head clamp inserted into the U-shaped bearing portion of the carrier can be supported using a portion of the belt holder, that is, the receiving portion. Therefore, the number of head clamp assembly parts can be reduced and the assembly work can be easily performed.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a plan view, the second figure is an exploded perspective view, and the third figure is a first
4 and 5 are longitudinal sectional side views taken along the line A--A in the drawings, and partial longitudinal sectional front views showing modified examples of the attachment means for the belt presser. DESCRIPTION OF SYMBOLS 1...Platen, 3...Carrier, 11...Printing head, 12...Mounting flange (part of printing head), 13...Mounting surface, 18...Bearing portion, 19
... Head clamp, 21 ... Pressing part, 24 ...
Belt holder, 27...Timing belt (belt), 29...Receptacle.

Claims (1)

[Scope of Claims] 1. A mounting surface that supports a part of the print head is formed on a carrier that moves along the platen, and a belt holder that holds a belt for driving the carrier is screwed to the carrier, and each of the print heads is attached to the carrier. A pair of left and right head clamps each having a pressing part that presses both sides of the carrier against the mounting surface and a hinge shaft part are provided, and a U-shaped bearing part with one side open into which the hinge shaft part is inserted is formed on both sides of the carrier. A printing head holding mechanism for a printing device, characterized in that a receiving portion for supporting the hinge shaft portion of the head clamp from the open side of the bearing portion is integrally formed on the belt holder. 2. Claim 1, characterized in that the rotation angle of the head clamp in the release direction is regulated within a certain range by a part of the receiving part of the belt presser.
Print head holding mechanism of the printing device described in Section 1. 3. A printing head holding mechanism for a printing device according to claim 1, characterized in that a belt holder is tightened to the carrier with a screw, and the belt is held between the belt holder and the carrier.