JPS592630B2 - Thermal recording device housing opening/closing mechanism - Google Patents

Description

[Detailed description of the invention] The present invention relates to a housing opening/closing mechanism for a thermal recording device.

Referring to FIG. 1, the mechanism of the opening/closing part of the housing of a conventional thermal recording device such as a facsimile will be explained.

Between the pair of side plates 1 and 2, which are the base of the device, there is a roll of thermal recording paper 4 below, a recording paper guide Tb diagonally above it, a platen roller 16 above it, and a thermal roller in pressure contact with the platen roller. A cutter unit 17 with a cutter γ attached thereto is disposed diagonally to the side of the head unit 11 and the platen roller. The thermosensitive recording paper 4 is inserted into the groove of the recording paper insertion guide 3 attached to the side plates 1 and 2 via the paper holder 5, which is fitted into the paper tube, and the brake plate is pressed into contact with the paper holder 5. 6 and tensioned.

The thermal recording paper 4 is guided by a recording paper guide T, is sent upward by a platen roller 16, and is thermally recorded by a thermal head unit 11 that is in pressure contact with the thermal recording paper 4. The fed recording paper on which thermal recording has been completed is cut by a cutter unit 17. A microswitch 8 attached to the recording paper guide T detects the presence or absence of thermal recording paper 4, and has the role of stopping the operation of the thermal head unit 11 and the rotation of the platen roller 16 when the thermal recording paper runs out. are doing. The front cover 18, which is the opening/closing part of the housing,
It covers the front side of the device and forms a housing together with the main body cover 19. Inside this front cover 18, a rotary side plate unit 18, which is another opening/closing member, is arranged.
The rotating side plate unit is supported so as to be rotatable approximately 900 degrees in the direction of arrow A around a fulcrum shaft 9 stretched between the lower ends of the side plates 1 and 2. At the upper end of the rotating side plate unit 10,
A pair of lock levers 14 are rotatably mounted around the support shaft 14, and the lock levers engage lock pins 13 provided on the side plates 1 and 2 to position the rotating side plate unit 10 when closed. and lock. The tips of the pair of lock levers 14 are fixed to both ends of the handle shaft 15. Further, the rotating side plate unit 10 is connected to the platen roller 1.
The thermal head unit 11 is elastically supported by a compression spring 12 on a bracket 117 fixedly installed on the 6 side, and when the rotating side plate unit 10 is closed, the thermal head unit 1 is
1 is urged to come into pressure contact with the platen roller 16.

In such a configuration, when loading the thermal recording paper 4 into the recording paper insertion guide 3 or when removing paper scraps attached to the thermal head unit 11, the rotating side plate unit 10 is moved to the position shown by the dashed line. It needs to be opened up.

In this case, first open the front cover 18, then grasp the handle shaft 15 by hand, rotate the lock lever 14 upward around its support shaft 11, and release the engagement with the lock pin 13. , the procedure for opening the rotating side plate unit 10 is extremely poor in operability.This is particularly important for general office applications such as thermal recording devices such as facsimiles, where the operability of the opening/closing part of the housing is one of the important selling points. The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a mechanism for opening and closing the housing of a heat-sensitive device that is easy to operate and has a simple structure.

The purpose of this is to elastically support the thermal head unit on the front cover that constitutes the opening/closing part of the casing, and to use the reaction force of the compression spring that urges the thermal head unit to come into pressure contact with the platen roller. This is achieved by a configuration that obtains a turning moment to open the cover.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 2, the same symbols as in FIG. 1 represent the same parts or equivalent parts.

The front cover 20, which is the only opening/closing part of the casing, covers the front side of the thermal recording device, and together with the main body cover 19 constitutes the casing of the device.

The front cover 20 is supported by a shaft hole drilled in its lower end so as to be rotatable about 900 degrees around a fulcrum shaft 9 in the direction of arrow A, and has lock pins 21 projecting outward from both sides of its upper end. ing. The locking means of the front cover 11 is as follows:
A lever shaft 23 pivotally supported by the side plates 1 and 2, and the lever shaft 2
3, and a spring (not shown) that biases the lock lever 22 upward (clockwise in the figure) around the lever shaft 23. The lock lever 22 resists the biasing force of the spring.
There is also a release button (not shown) that is pressed down. The lock lever 22 has an upwardly inclined portion at its tip, followed by an upwardly directed groove. Elastic means for buffering the rotational moment of the front cover 20 that opens due to its own weight are the support body 24 and the mounting plate 25 fixed to the side plate 1.
and a coil spring 26 stretched between the two. The point P at which the coil spring 26 is latched to the support body 24 is the position where the front cover 20 rotates in the direction of arrow A and begins to open under its own weight, that is, the vertically projected position of its center of gravity. When it is on the axis of the fulcrum shaft 9, it is fixed to the lower end of the side surface of the front cover 20 so that it is on the straight line L connecting the point on the mounting plate 25 where the coil spring 26 is hooked and the axis of the fulcrum shaft 9. It is set up. With this configuration, the coil spring 26 is attached to the support body 2.
In a range where the latching point P of the coil spring 4 is below the straight line L, a turning moment is applied to the front cover 20 in the opening direction, and in a range beyond the straight line L, a turning moment is applied to the front cover 20 in the closing direction. 2 and 3, the thermal head unit 2
7 to the front cover 20 will be explained.

The thermal head unit 27 is connected to its platen roller 16.
Guide grooves 28 are fixed at both ends of the front cover 20, and two mounting bosses 2' are provided at both ends of the front cover 20.
r' is provided protrudingly.

The guide groove 28 has a width that engages with the outer diameter of the shaft support 29, and the bearing 29 is fixed to the side plates 1 and 2 and pivotally supports the platen roller 16. The thermal head unit 27 is pressed by four compression springs 30 stretched between its mounting boss 277 and mounting seats 2σ protruding from both vertical edges of the front cover 20, and the guide groove 28 is pressed against the bearing. When not engaged with the front cover 29, both ends thereof are locked by bent portions 31' of a guide body 31 fixed to both side surfaces of the front cover 20.

In this state, the thermal head unit 27 is elastically supported by the front cover 20 and is freely rotatable in the direction of arrow B, and freely movable in the directions of arrows C and D. Further, when the front cover 20 is closed, the thermal head unit 27 is urged by the compression spring 30 so as to come into pressure contact with the platen roller 16. This compression spring 30
The biasing force becomes a reaction force that tries to open the front cover when the closing lock of the front cover 20 is released. In the figure, F: Reaction force of the biasing force of the compression spring 30 T2: F Arm of the moment around the fulcrum axis 9 of W: Weight t1 of the front cover 20: Arm of the moment around the fulcrum axis 9 of W: Friction torque G that prevents rotation of the front cover 20 in the direction of arrow A
: When the center of gravity of the front cover 20 is F-4>W-T, +T, and at least the force of the front cover 20 (the position where it starts to open due to its own weight, that is, the vertical projection position of G (W until the position where the extension line of ) exceeds the axis of the fulcrum shaft 9,
The spring constant of the compression spring 30 is set to be sufficient to rotate the front cover 20.

The operation of this embodiment configured as above will be explained.

When the front cover 20 is rotated and closed, the thermal head unit 27 that is elastically supported by the front cover is rotatable in the direction of arrow G and movable in the direction of arrow D, so that the guide groove 228 first closes. At the rounded corner of the tip,
The groove then engages the bearing 29 to position the thermal head unit 27.

At the same time, the locking pin 21 of the front cover 20 first engages with the sloped portion at the tip of the lock lever 22, and then engages with the groove to position and lock the front cover 20 when closed. When opening the front cover 20, the release button is pressed down, and the lock lever 22 rotates downward (counterclockwise in the figure) around the lever shaft 23, disengages from the lock pin 21, and releases the lock.

Then, the rotation moment due to the reaction force F of the biasing force of the compression spring 30 set as described above is generated by the front cover 2.
0 begins to open due to its own weight, the front cover 20 is urged and fixed in the direction of arrow A. At this time, the coil spring 26 of the elastic means is also compressed by the compression spring 3 as described above.
0 to urge the front cover 20 to rotate in the direction of arrow A. Subsequently, the front cover 20 rotates in the direction A due to its own weight, but the rotation moment in the opening direction is buffered by the tension of the coil spring 26.
Smoothly rotate about 900 times to the position indicated by the chain double-dashed line.

According to this embodiment, the front cover 20 can be closed and opened with a single touch, resulting in extremely good operability.

As described in detail above, according to the present invention, a thermal recording device can be operated by utilizing the reaction force of a compression spring disposed to bias and press a thermal head unit against a platen roller with a simple structure. This has the effect of providing good opening/closing operability of the housing opening/closing section.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing a housing opening/closing mechanism of a conventional thermal recording device, Fig. 2 is a side sectional view showing an embodiment of the present invention, and Fig. 3 is a sectional view taken along the X arrow in Fig. 2. It is. 1, 2... Side plate, 9... Fixed shaft, 10... Rotating side plate unit, 11, 27... Thermal head unit, 12, 30... Compression spring, 13, 21... Lock pin , 14, 22... Lock lever, 15... Handle shaft, 16... Platen roller, 17... Cutter unit, 18, 20... Front cover, 19... Body cover, 23... Lever shaft, 24...Support, 2
6... Coil spring, 28... Guide groove, 29... Bearing, 31... Guide body.

Claims (1)

[Claims] 1 A fulcrum shaft provided at the lower end of the base of the thermal recording device,
a front cover rotatably supported around the fulcrum axis and forming an opening/closing part of the housing of the thermal recording device; a locking means for positioning, locking and unlocking the front cover when closed; A compression spring that elastically supports a thermal head unit in charge of recording on the front cover and urges the thermal head unit to come into pressure contact with a platen roller that feeds thermal recording paper when the front cover is closed, and a compression spring that is released by its own weight. The housing opening/closing mechanism of a thermal recording device is provided with elastic means for buffering the rotational moment of the front cover, and the front cover is moved in the opening direction by the reaction force of the biasing force of the compression spring when the front cover is unlocked. When the front cover is rotated to a position where the rotational moment biasing the front cover is greater than the sum of the rotational moment in the closing direction due to the front cover's own weight when closing and the frictional moment resisting the opening of the front cover, the front cover is rotated to the position where it starts to open due to its own weight. 1. A housing opening/closing mechanism for a heat-sensitive recording device, characterized in that the mechanism is sufficient for movement.