JPS6312256Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission structure including a power transmission shaft for transmitting rotational power between a driving part and a driven part.

Usually, a simply rod-shaped shaft is used as the shaft for transmitting rotation between the driving part and the driven part.

However, coil springs are used in cases where the accuracy of the axis between the driving part and the driven part is not high.

In any case, such power transmission shafts are fixed to the driving part or the driven part by screws.

However, in such a power transmission shaft, if either the driving part or the driven part or both are frequently removed, the screws must be unscrewed each time they are removed, making the work very laborious. It had the drawback of becoming complicated.

Therefore, the purpose of the present invention is to provide a power transmission structure including a new power transmission shaft that eliminates the above-mentioned drawbacks. a small casing supported so as to be swingable, a drive motor attached to the small casing; one end connected to the end structure of the drive shaft on the drive shaft side of the drive motor in a winding direction; a coil spring whose other end is coupled and engaged with one end of a driven part side member in a winding direction; and an engagement member as an engagement structure with a driven shaft on the other end side of the driven part side member. A power transmission shaft comprising a structure that engages and holds the engaging member so as to be able to move a predetermined stroke in the direction of the non-rotatable shaft, and a compression spring that always biases the engaging member toward the driven shaft; a driven body including a driven shaft having an end corresponding structure that faces and can engage with the end of the engagement member on the other end side; and a power transmission shaft mounted on the drive shaft in the first attitude. a corresponding structure on the fixed housing side that positions and accommodates the driven body such that the corresponding structure for the end of the driven shaft is disposed at a position and direction where it can be press-fitted approximately coaxially and in the same direction as the end of the engaging member; By arranging the driven body at a predetermined position of the fixed casing and placing the small casing in the first posture, the structure is such that the driven shaft can be driven via the power transmission shaft, and the second This is achieved by making the driven body disengage from the driven shaft by taking the posture, thereby making it possible to remove the driven body.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a block diagram of the power transmission shaft portion of the present invention.

In the figure, 1 is the drive part side shaft, 2 is the driven part side shaft,
3 represents a coil spring, 4 represents a protrusion, and 5 represents a compression spring.

As shown in the figure, the power transmission shaft of the present invention has a coil spring 3 wound in a direction tightening in the forward rotation direction between the drive part side shaft 1 and the driven part side shaft 2.
The drive part side shaft 1 is directly connected or fixed by screws to a drive part (not shown). The coil spring 3 is a so-called clutch mechanism in which it is tightened in the forward rotational direction to transmit power, but loosened in the reverse rotational direction so that no rotation is transmitted. In addition, the driven part side shaft 2 is designed so that the driven part (not shown) can be easily removed.
The protrusion 4 is inserted into a hole at the end of the driven part (not shown).

The projection 4 is movable in the axial direction, and a compression spring 5 is provided inside the shaft 2, and normally protrudes to the outside of the projection 4, so that when an external force is applied to the projection, It has a structure that fits inside the chisel shaft.

Next, Figures 2 and 3 show an example in which the power transmission shaft of the present invention shown in Figure 1 is actually applied to a device.
Illustrated in the figure.

In FIGS. 2 and 3, the same symbols as in FIG.
1 and 2 respectively show an ink ribbon cassette as a driven body.

FIGS. 2 and 3 show the ink ribbon cassette 9 and its driving section of a printing device, and the ink ribbon cassette 9 is frequently removed from this device.

In the figure, FIG. 2 shows the ink ribbon cassette 9.
FIG. 3 shows the ink ribbon cassette 9 installed in the apparatus.

As shown in FIG. 2, before the ribbon cassette 9 is installed, the drive motor 7 and the power transmission shaft attached to the drive motor are retracted together with the casing 8, and the ribbon cassette 9 is not inserted into the apparatus. When installed, the casing 8 is pushed down by the ribbon cassette 9 and the power transmission shaft is set in the ribbon cassette 9, as shown in FIG.

In this case, the protrusion 4 of the power transmission shaft and the drive transmission hole 6 of the ribbon cassette 9, which is the driven part, do not necessarily match completely, so if they do not match, the protrusion 4 resists the compression spring 5 It's inside this.

However, when the drive motor 7 is driven to drive the ribbon cassette 9, the power transmission shaft rotates.
When the protrusions 4 and 4 are aligned, the protrusions 4 protrude from the shaft 2 and completely engage with the drive transmission hole 6.

In this way, by using the power transmission shaft of the present invention, the accuracy between the shafts is not relatively improved, and by using the configuration shown in Figs. 2 and 3, the driven side can be moved very easily. A replaceable power transmission structure can be provided.

[Brief explanation of the drawing]

Fig. 1 shows the configuration of the power transmission shaft portion of the present invention, Fig. 2 shows the state before the ribbon cassette is installed in a printing device using the power transmission structure including the power transmission shaft of the present invention, and Fig. 3 shows the state before the ribbon cassette is installed. Indicates the condition. Furthermore, in the figure, 1 is a drive part side shaft, 2 is a driven part side shaft, 3 is a coil spring, 4 is a protrusion, 5 is a compression spring, 6 is a drive transmission hole of the driven part, 7 is a drive motor, and 8 is a housing. , 9 indicate ink ribbon cassettes, respectively.

Claims (1)

[Claims for Utility Model Registration] A small casing that is swingably supported so as to take a first attitude and a second attitude with respect to a fixed casing, a drive motor attached to the small casing, a coil spring whose one end is coupled and engaged with the end structure of the drive shaft on the drive shaft side of the drive motor in the winding direction, and whose other end is coupled and engaged with one end of the driven part side member in the winding direction; A structure that engages and holds an engagement member as an engagement structure with a driven shaft on the other end side of the driven part side member so as to be movable by a predetermined stroke in the direction of the non-rotatable shaft, and the engagement member is always driven. A power transmission shaft composed of a compression spring biased toward the shaft side, and a driven shaft having an end corresponding structure that faces and can be engaged with an end of an engagement member on the other end side of the power transmission shaft. an end of the driven shaft in a position and direction that can be press-fitted substantially coaxially and in substantially the same direction as the end of the engagement member of the power transmission shaft mounted on the drive shaft in the first attitude; The driven body is arranged at a predetermined position of the fixed housing, and the small housing is arranged at a predetermined position of the fixed housing.
By adopting this posture, the driven shaft can be driven via the power transmission shaft, and by taking the second posture, the engagement with the driven shaft can be disengaged, allowing the driven body to be removed. A power transmission structure characterized by: