JPH0436938Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) This invention relates to a printer in which a carriage with a printing head mounted on a guide rod extending parallel to the longitudinal direction of the platen is mounted. ,
This invention relates to a support device for a carriage guide rod.

(Problem that the invention aims to solve) If the printer frame is molded from synthetic resin, it can be prevented from deforming due to the difference in thermal expansion coefficient with the metal guide rod, and the guide rod can be attached to it according to the thickness of the printing paper. Together with the suspended printing head, it is necessary to move it close to and away from the platen so that the appropriate printing interval can be adjusted.To do this, the bearings at both ends of the guide rod must be placed in a position that takes into account expansion and contraction due to thermal expansion and also in relation to the platen. It has no choice but to have a complex structure that allows it to be moved.

This invention attempts to achieve the above requirements with a simple structure and at low cost.

Structure of the invention (means for solving the problem) This invention is a printer in which a carriage with a print head mounted is mounted on a guide rod extending parallel to the length of the platen, and at both ends of the guide rod: An eccentric shaft formed eccentrically with respect to the axis of the guide rod, a frame, and a frame that is fitted into a fitting hole formed in the frame so that the eccentric shaft can be slid in the axial direction and around the axis. A configuration is adopted that includes a bearing member having a bearing hole that is rotatably inserted and supported, and an adjusting means that rotates the eccentric shaft portion about the shaft.

(Function) Therefore, in this invention, deformation due to the difference in thermal expansion between the guide rod and the upper frame can be absorbed by the guide rod sliding in the axial direction with respect to the bearing member. Further, the distance between the platen and the guide rod is adjusted by means of an adjusting means fitted to the guide rod.

(Example) Hereinafter, an example of a printer embodying this invention will be described in detail with reference to the drawings.

Now, in the printer of this embodiment, the second
As shown in Figures 1 to 4, a lower frame 1 is formed of synthetic resin into a substantially box shape with an open top, and an upper frame 2 made of synthetic resin is attached to the rear upper part of the lower frame 1. A pair of left and right fitting holes 3 are formed on the rear wall of the lower frame 1, and a pair of left and right protrusions 5 are formed on the rear surface of the upper frame 2 to fit into the fitting holes 3 via elastic caps 4 made of rubber. has been done. lower frame 1
A pair of left and right rubber elastic cylinders 6 are fitted to the front edges of the upper frame 2. By screwing screws 8 from the upper surface of the upper frame 2 into the nuts 7 held at the lower ends of the upper frame 2, the upper frame 2 is fixed. It is removably fixed on the lower frame 1.

A bottom cover 10 is fixed to the opening 9 provided at the bottom of the lower frame 1 with a plurality of screws,
A circuit board 11 that supports the control circuit of this printer is fixed to the upper surface thereof by the screws. A power supply unit 13 is removably attached to the front right end of the lower frame 1, and includes power supply-related electrical parts such as a transformer, a capacitor, and a switch. To the left of the power supply unit 13, a front cover 14 is attached to the front upper part of the lower frame 1 so that it can be opened and closed, and a transparent cover 15 is attached to the front upper part of the upper frame 2 so that it can be opened and closed.

As shown in FIGS. 2 to 4, a platen 16 is rotatably supported between the left and right side walls 2a and 2b of the upper frame 2 via a bearing member 17, and an operation knob 18 is attached to the left end of the platen 16. There is. Platen 16
Both side walls 2a, 2b of the upper frame 2 in the vicinity of
A metal guide rod 19 is installed between them and extends in parallel along the longitudinal direction of the platen 16. Platen 16 with this guide rod 19 in between.
A metal guide rail 20 having a substantially horizontal U-shaped cross section is installed between both side walls 2a and 2b of the upper frame 2 so as to be located on the opposite side of the upper frame 2, and extends parallel to the guide rod 19.

A metal carriage 21 is movably mounted on the guide rod 19, and a printing head 22 is mounted on the upper surface of the carriage 21. As shown in FIGS. 3 and 4, the guide rail 2 is mounted on the carriage 21.
A protruding piece 23 is formed to protrude toward 0, and an engaging body 24 is attached to the tip thereof. And the third
As shown in the figure, this engaging body 24 is connected to the guide rail 2.
Engage to sandwich the upper side of 0 from above and below,
The guide rail 20 guides the movement of the carriage 21 along the longitudinal direction of the platen 16. Platen 1 across print head 22
A ribbon cassette 25 is removably mounted on the upper frame 2 so as to be located on the opposite side from the ribbon cassette 6. An ink ribbon 26 is housed inside the ribbon cassette 25, and a part of the ink ribbon 26 is stored inside the ribbon cassette 25.
Externally, it is located between the platen 16 and the print head 22.

As shown in FIG. 4, a metal support plate 27 is attached to the lower right side of the upper frame 2, a platen drive motor 28 is supported on its right side, and a carriage drive motor 29 is supported on its lower surface.
is supported. When the platen drive motor 28 is rotated, the platen 16 is rotated in either forward or reverse direction via the reduction gear mechanism 30.
A feed is applied to the printing paper on the platen 16.
Further, when the carriage drive motor 29 is rotated, a reduction gear mechanism (not shown) and a toothed pulley 3 are rotated.
1 and the carriage 21 via the toothed belt 32.
is moved either to the left or right in the longitudinal direction of the platen 16, and the print head 22 on the carriage 21 prints on the print paper on the platen 16 via the ink ribbon 26. Furthermore, when the carriage drive motor 29 rotates, a ribbon feed shaft 33 on the ribbon cassette 25 is rotated in one direction via a reduction gear mechanism (not shown), so that the ink ribbon 26 is fed by a predetermined amount. .

Next, the support device for the guide rod 19, which is the main part of this invention, will be explained. As is clear from FIG. 1 and FIGS. 5 to 9, the upper frame 2 is attached below the platen 16 and guide rod 19. It has a bottom wall 2c located in parallel, and left and right side walls 2a, 2b standing upright at both left and right ends thereof, which are integrally formed, and the left and right side walls 2a, 2b have inner walls 2a-1, 2b-1, respectively. It consists of outwardly spaced outer walls 2a-2, 2b-2. The inner and outer walls are connected to each other at the upper end,
The bottom end is open.

Each inner wall 2a-1, 2b-1 has a fitting hole 41.
are respectively formed, and the outer wall 2a- of the left side wall 2a
A through hole 42 is formed in 2 in correspondence with the fitting hole 41. A bearing member 43 made of synthetic resin is rotatably fitted and supported in each fitting hole 41 on one side of the outer circumferential shaft portion 43a, and the center of the outer circumferential shaft portion 43a is parallel to the axis of the outer circumferential shaft portion 43a. A bearing hole 43b is formed extending on an axis eccentric to the axis, and an engaging protrusion 43c is provided protruding from one side of the outer periphery.

On the other hand, eccentric shaft portions 19b are formed at both ends of the guide rod 19 to protrude so as to extend on an axis that is parallel to the axis of the central guide shaft portion 19a and eccentric with respect to the axis. A notch 19c is formed in the shaft portion 19b. The guide rod 19 has eccentric shaft portions 19 at both ends.
b is fitted into the bearing hole 43b of the both-end bearing member 43, and is mounted and supported between both the bearing members 43 so as to be rotatable around its axis, and the eccentric shaft portion 1
A stop ring 44 attached to the tip of 9b prevents it from coming off to the left across the bearing member 43 on the same side.

A plurality of positioning recesses are provided on the outer surfaces of both inner walls 2a-1 and 2b-1 of the upper frame 2, which are located on the outer periphery of each of the fitting holes 41 and can be engaged with the engagement protrusions 43c on each bearing member 43. 45 are formed respectively. The positioning recess 45 and the engagement protrusion 4
3c constitutes a positioning means 46, and during assembly, each bearing member 43 is rotated and adjusted so that the engagement protrusion 43c and any positioning recess 45 are aligned.
The axis of the guide shaft portion 19a of the guide rod 19 can be adjusted to be parallel to the axis of the platen 16 by positioning it at a predetermined rotational position by engaging with the guide rod 19.

A guide rod 1 is installed so as to protrude outward from a through hole 42 on the left outer wall 2a-2 of the upper frame 2.
An operating member 47 made of synthetic resin as an adjustment means is fitted and fixed to the tip of the left eccentric shaft portion 19b of 9.
A regulating recess 47a for regulating the rotational range and a plurality of holding recesses 47b for setting and holding the rotational position at a predetermined rotational position are formed on its outer periphery.
As shown in FIG. 5, an indicator 48 corresponding to the thickness of the printing paper is provided on the outer surface of the left outer wall 2a-2 of the upper frame 2 facing the operating member 47. The member 47 can be rotated.

As shown in FIGS. 1, 5, 6, and 8, a holding member 4 made of synthetic resin is provided between the inner and outer walls of the left side wall 2a of the upper frame 2 in the vicinity of the operating member 47.
9 is installed. Each holding member 49 has a locking claw 49b on the upper surface of one end, a stacking portion 49c on the lower surface of the same end,
A locking piece 49a is integrally formed on the upper surface of the other end. Also, a pair of arms 50 are formed protrudingly on the upper surface of the other end, and the tip of one arm 50 engages with the regulating recess 47a of the operating member 47, so that the operating member 4
A regulating protrusion 50a for regulating the rotation of the operating member 7 within a predetermined range is formed protrudingly, and a holding recess 47 of the operating member 47 is provided at the tip of the other arm 50.
A holding protrusion 50b is formed to protrude and selectively engage with the holding protrusion 50b to set and hold the operating member 47 at a predetermined rotational position. And this holding member 49
The upper holding protrusion 50b and the holding recess 47b on the operating member 47 constitute a holding means 51.

A U-shaped recess 2d is formed in the left side wall 2a corresponding to the operation knob 18 of the platen 16, and the bottom wall 2e bridges the inner and outer side walls 2a-1 and 2a-2 at the lower end, It is cut out from the arcuate wall of the recess 2d. The holding member 49 has a hook 49b and a hook 49a removably attached to both ends of the wall 2e, and the pair of arms 50 are positioned corresponding to the operating member 47 as described above.

On the other hand, as shown in FIG. 5, a bearing member 17 for supporting the platen 16 has a pair of flanges 17a and 17b sandwiching the periphery of the U-shaped notch 2f in the side walls 2a and 2b, and one of the flanges A projecting piece 53 is integrally formed at the bottom of the recess 2d to be inserted through the insertion hole 52 formed at the bottom of the recess 2d. 54 is formed. In this embodiment, when the holding member 49 is attached to the lower surface of the upper frame 2, one side of the holding member 49 is arranged to face the lower end of the protrusion 53, and the protrusion 53 is located at the ninth
It is configured to prevent the latch claw 54 from coming out of the engaged state when moved in the direction of the arrow in the figure.

Now, in the printer configured as described above, after the platen 16 is assembled to the upper frame 2,
When assembling both ends of the guide rod 19, it is inserted into the fitting holes 41 of both inner walls 2a-1 and 2b-1, and then the bearing holes 43b of the bearing member 43 are fitted to both ends of the guide rod 19. The outer peripheral shaft portion 43a of the coaxial bearing member 43 is fitted into the fitting hole 41. In this state, the rotation of both bearing members 43 is adjusted separately, and the engagement protrusion 43c and the arbitrary positioning recess 45 are adjusted.
When positioned at a predetermined position by engagement with the guide shaft portion 19a, the axes of both eccentric shaft portions 19b are moved separately, and the axis of the guide shaft portion 19a can be easily and accurately adjusted to be parallel to the axis of the platen 16. can.

The right end of the guide rod 19 is connected to the right inner wall 2b.
-1, with a bearing member 43 interposed between them, and is prevented from coming off by a stop ring 44. Left bearing member 4
3 is pressed and held against the left inner wall 2a-1 by the side surface of the arm portion 50 by attaching the holding member 49 to the wall 2e as described above. The operating member 47 is fitted into the end of the guide rod 19 from the outside of the frame 2 through the through hole 42. upper frame 2
The lower surface of the holding member 49 is also covered by the lower frame 1. When the guide rod 19 becomes hot due to friction with the carriage 21 while using the printer, or when the temperature changes, the guide rod 1
The difference in thermal expansion between the guide rod 19 and the frame 2 is absorbed by the eccentric shaft portion 19b of the guide rod 19 sliding on the left bearing member 43 in the axial direction. For this purpose, the left eccentric shaft portion 19b is formed sufficiently long to a position inwardly away from the inner wall 2a-1, as shown in FIG.

Furthermore, if the thickness of the printing paper on the platen 16 changes during use of the printer, the operation member 47 is rotated in accordance with the instructions of the index 48 corresponding to the thickness of the printing paper, so that the holding recess 47b and the desired When the guide rod 19 is set and held in a predetermined position by engagement with the holding protrusion 50b, the guide rod 19 is attached to the eccentric shaft portion 19b.
The guide shaft portion 19a is moved toward or away from the platen 16 while its axis remains parallel to the axis of the platen 16. Therefore, print head 2
The second printing section is arranged at a predetermined distance from the surface of the printing paper, and uniform printing can be performed in this state. Note that when the operating member 47 is rotated, the regulating recess 47a and the regulating protrusion 50a on the holding member 49 engage with each other, so that the operating member 47 is rotated.
Since the rotation of the operating member 47 is restricted within a predetermined range, the rotation setting position of the operating member 47 will not be deviated.

It should be noted that this invention is not limited to the configuration of the above-mentioned embodiments, and it is also possible to embody the invention by changing the configuration of each part arbitrarily within a range that does not depart from the spirit of this invention.

Effects of the invention As described above, this invention has a simple structure, prevents deformation due to the difference in coefficient of thermal expansion between the guide rod and the frame, and allows appropriate adjustment of the distance between the printing head and the platen.

[Brief explanation of the drawing]

Fig. 1 is a partially exploded perspective view showing a support device for a carriage guide rod in a printer embodying this invention, Fig. 2 is a perspective view showing the entire printer, and Fig. 3 is a longitudinal cross-sectional view of essential parts of the printer. Fourth
The figure is also a partial horizontal sectional view, FIG. 5 is a partially exploded perspective view showing the mounting configuration of the platen bearing member, and FIG.
7 is a partial sectional view taken along line A-A in FIG. 6; FIG. 8 is a partial sectional view taken along line BB in FIG. 6; FIG. 9 is a partial sectional view taken along line CC in FIG. 6. 2... Upper frame, 16... Platen, 19...
...Guide rod, 19a...Guide shaft portion, 19b...
... Eccentric shaft portion, 21 ... Carriage, 22 ... Print head, 41 ... Fitting hole, 43 ... Bearing member, 4
3a...Shaft portion, 43b...Bearing hole, 46...Positioning means, 47...Operation member, 51...Holding means.

Claims (1)

[Claims for Utility Model Registration] A printer in which a carriage 21 on which a printing head 22 is mounted is mounted on a guide rod 19 extending parallel to the length direction of the platen 16, wherein the guide rod 19 is mounted at both ends of the guide rod 19. an eccentric shaft portion 19b formed eccentrically with respect to the axis of the frame 2; and a frame 2, which is fitted into a fitting hole 41 formed in the frame 2, and is capable of sliding on the eccentric shaft portion 19b in the axial direction thereof; A guide rod support device for a printer carriage, comprising: a bearing member 43 having a bearing hole 43b that is inserted and supported so as to be rotatable around an axis; and an adjusting means 47 that rotates the eccentric shaft portion 19b about the shaft.