JPH0739660Y2 - Printer cover open / close mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a mechanism for opening and closing a cover body arranged on an upper part of a main body of a printer device.

[Conventional technology]

As shown in FIG. 8, a printer device, for example, a line thermal type thermal transfer recording device, has a mechanism portion 1, a cover body 2 disposed on the upper portion of the mechanism portion 1, and an opening / closing shaft portion 3 for opening and closing the cover body 2. It has a lock part 4 for keeping the cover body 2 closed, and a paper 7 is provided between the head part 6 installed in the mechanism part 1.
The ink sheet 8 is sandwiched between them and printing is performed by a heat pulse from the head unit 6.

Torsional springs 9a and 9b are used for this opening / closing mechanism. As shown in FIG. 4, the opening / closing shaft portion 3 penetrates through the side surface holes 11a and 11b of the mechanism portion 1 and the side surface holes 21a and 21b of the cover body 2, and the bearing 10
Has been inserted through. Further, a pair of symmetrically shaped torsion springs 9a, 9b are passed through the opening / closing shaft portion 3 through the shaft. Torsion springs 9a, 9b
The arms 91a, 91b on one side are fitted into the holes 12a, 12b provided in the mechanism portion 1, and the other arms 92a, 92b are fitted in the notches 22a, 22b provided in the cover body 2. That is, the cover body 2 is biased in the open state about the opening / closing shaft portion 3 by the combined twisting moment of the twisting angles formed by the both torsion springs.

On the other hand, when the cover body 2 is closed, the lock portion 4 supported by the mechanism portion 1 is used as shown in FIG. The lock part 4 has a catch part 40a at the tip of the arm part 40,
The cover body 2 is pulled toward the opening / closing shaft portion 3 by the 1
The hooked portion 40a of the arm portion 40 is hooked in the hole portion 23 provided in the closed state, whereby the closed state is achieved. The angle portion 42 is fixed to the arm portion 40 with a screw 43, and by pushing the angle portion 42 downward, the arm portion 40 rotates and the catch is removed, and the cover body 2 is centered around the opening / closing shaft portion 3. It opens by the resultant moment of the torsion spring.

[Problems to be solved by the device]

However, the above-mentioned cover opening / closing mechanism has the following problems when the lock body 4 is opened to open / close the cover body 2.

The moment required for opening and closing is as shown in FIG. 7G. When the cover body 2 is closed, a moment larger than the moment when the cover body 2 is opened is required at an opening and closing angle of 0 to 20 degrees due to factors such as the weight and inertia of the cover body 2. Therefore, when the lock is released, the combined twisting moments H and I by the two torsion springs 9a and 9b become larger than the opening and closing moment G of the cover body 2, and the cover body 2 opens vigorously.

Further, when the opening / closing angle is about 40 degrees, if the resultant moment of both torsion springs 9a and 9b is set to be smaller than the opening / closing moment G of the cover body 2 as H, the opening momentum can be reduced, but on the other hand, the maximum opening / closing When the angle is about 90 degrees, the cover body 2 cannot be held in the state of the maximum opening / closing angle. Further, if the resultant moment of both torsion springs 9a, 9b is set to be larger than the opening / closing moment G of the cover body 2 as shown by 1, the cover body 2 will open vigorously.

As described above, the conventional cover opening / closing mechanism has many problems in its opening / closing balance.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention inserts a double torsion type torsion spring that works only from the initial stage to the middle stage of the opening / closing angle together with both torsion springs to cover the combined torsional moment at the initial opening / closing angle. Is larger than the opening / closing moment of the cover body, the opening / closing angle is smaller than the cover body opening / closing moment in the middle period, and the final opening / closing angle is larger than the cover body opening / closing moment. .

[Action]

That is, since the opening / closing angle, the initial twisting moment of the total torsion spring is larger than the opening / closing moment of the cover body, the cover body does not vigorously close due to the weight or inertia of the cover body when it is closed, and The cover body can be opened reliably. Further, since the combined twisting moment is set to be smaller than the opening / closing moment of the cover body in the middle of the opening / closing angle, the cover body can be prevented from opening vigorously and the cover body can be opened in a substantially balanced state. Furthermore, at the end of the opening / closing angle, the combined twisting moment was made larger than the opening / closing moment of the cover,
The cover body does not close by its own weight and can be held in the open state.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an opening / closing mechanism according to the present invention, and FIG. 2 is a sectional view showing the action of a double torsion spring.

As described above, the cover body 2 is disposed on the upper portion of the mechanism portion 1, and the opening / closing shaft portion 3 penetrates the both side surface holes 21a and 21b of the cover body 2 and the both side surface holes 11a and 11b of the mechanism portion 1, Two torsion springs 9a and 9b having a symmetrical shape and a double torsion type torsion spring 9c are axially passed through the opening / closing shaft portion 3. The arms 91a, 91b on one side of the two torsion springs 9a, 9b having the symmetrical shape are fitted into the holes 12a, 12b provided in the mechanism portion 1, and the other arms 92a, 92b.
Fits into the notches 22a and 22b provided in the cover body 2.

The arms 91c and 92c of the double torsion spring 9c are attached to the holes 22c and 22d provided in the cover body 2, and the free angle α of the spring, the opening / closing angle β of the cover body 2 and the arm 93 of the spring 9c from the horizontal plane.
Angle γ until c is brought into contact with the frame portion 11 of the mechanism portion 1
When the relation of β + γ <α is satisfied, the double torsion type torsion spring 9c gives a torsion moment to the cover body 2 in the opening direction.

In such a state, the cover body 2 receives a combined torsional moment formed by the two torsion springs 9a, 9b and the double torsion type torsion spring 9c having symmetrical shapes in the opening direction.

Next, the relationship between the combined twisting moment and the opening / closing angle of each torsion spring having the above-mentioned configuration will be shown.

As shown in FIGS. 3 and 6, the torsion springs 9a and 9b have a free angle θ of 105 degrees, for example, when the cover body 2 is closed,
Each has a twisting moment c corresponding to 105 degrees, and the two have a twisting moment D.

On the other hand, in the double torsion type torsion spring 9c, the second
As shown in FIG. 2B, for example, when the free angle of the spring is α = 135 degrees and γ = 90 degrees, the torsion angle is 45 when the cover body 2 is closed.
It has a torsion moment E corresponding to degrees.

When the two torsion springs 9a and 9b having such a symmetrical shape and the double torsion torsion spring 9c are used, as shown in FIG. 6, when the opening / closing angle is 0 to 20 degrees, the three torsion springs are combined. Twisting moment F works to open securely, and it does not close with force. Further, in the vicinity of the opening / closing angle of 40 degrees, the moment E of the double torsion type torsion spring 9c disappears, and the combined torsion moment F becomes smaller than the opening / closing moment G of the cover body 2. Therefore, it is possible to prevent the cover body 2 from opening vigorously. When the torsion moment E of the double torsion type torsion spring 9c disappears, the double torsion type torsion spring 9c itself must be stopped, but the holes 22c and 22d are opened in the cover body 2 and the arm 91 is provided here.
If the structure is such that the c and 92c are attached, it will be prevented from coming off.

Further, when the cover body 2 reaches the maximum opening / closing angle, the opening / closing moment G of the cover body 2 becomes smaller and the cover body 2 has a symmetrical shape.
The torsional moments remaining on the individual torsion springs 9a and 9b make the cover body 2 self-supporting and hold it in the open state.

In this embodiment, the case where a single torsion spring of a double torsion type is used is described, but the same effect can be obtained even if a plurality of torsion springs are used.

[Effect of device]

As described above, the cover opening / closing mechanism of the present invention combines the torsion spring that acts from the early to late stages of opening and closing and the double torsion type torsion spring that acts from the early to mid stages of opening and closing to make the cover body smoothly over the entire opening and closing cycle. It can be opened and closed. As a result, the usability of the thermal recording device or the like is significantly improved, and maintenance such as ink sheet replacement can be efficiently and safely performed with the cover body open.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 (a) is an explanatory view when a double torsion type spring is closed, and FIG. 2 (b) is an explanation when the double torsion type spring is opened. Figure,
3 is an explanatory view showing the relationship between the torsion angle and the opening / closing angle of a torsion spring, FIG. 4 is a perspective view showing a conventional example, FIG. 5 is a sectional view showing a conventional example, and FIG. FIG. 7 is an explanatory view showing the relationship between the opening / closing angle of the cover and the moment, FIG. 7 is an explanatory view showing the relationship between the opening / closing angle of the cover and the moment in the conventional method, and FIG. 8 is a schematic side view showing the lock portion and the head portion. . 1 …… Mechanism part, 2 …… Cover body 3 …… Opening / closing shaft part, 4 …… Lock part 5 …… Platen, 6 …… Head 7 …… Paper, 8 …… Ink sheet 9a, 9b …… Torsion spring 9c ...... Double torsion type torsion spring 10 …… Bearing

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A cover body disposed on the upper part of the main body of the apparatus is opened and closed by a combined torsional moment of a plurality of torsion springs, and the torsion springs other than the both ends have a double torsion in which the opening and closing angle acts only from the initial stage to the middle period. By using the torsion spring of the mold, the combined twisting moment in the initial stage of opening and closing is made larger than the opening and closing moment of the cover in synchronization, the combined torsional moment in the middle of opening and closing is made smaller than the opening and closing moment of the cover in synchronization, and A cover opening / closing mechanism for a printer device, wherein the final twisting moment is made larger than the opening / closing moment of the cover body in synchronization.