JPS61290081A - Ink ribbon cartridge - Google Patents

Abstract

PURPOSE:To uniformize a tention on an ink ribbon and prevent defective printing from being caused by sagging of the ink ribbon at a printing part, by setting a rotation resistance to be larger when the roll diameter on a payout core is large and to be smaller as the roll diameter becomes smaller. CONSTITUTION:In the beginning stage after the start of use of the ink ribbon A, only a small portion of the ink ribbon A is taken up around a take-up core 12, so that the roll diameter on the take-up core 12 is a small, and the position of the core 12 is deviated to the right side. Therefore, the payout core 7 is pushed by a tip part of a tension spring 10, and a strong rotation resistance is exerted thereon. On the other hand, in the final stage of the use of the ink ribbon A, a major portion of the ribbon A is wound around the take-up core 12, so that the roll diameter on the core 12 is large, and the distance between the core 12 and a driving rotating body 18 is enlarged, resulting in that the core 12 is gradually moved leftward. As a result, the core 17 is pushed by a part near a fulcrum part 17 of the tension spring 10, so that a small rotation resistance is exerted thereon.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ink ribbon cartridge.

More specifically, the invention relates to an ink ribbon cartridge for storing ink ribbons used in typewriters, computer printers, and the like.

[Prior Art] Conventionally, ink ribbon cartridges include an unwinding core that is rotatably attached to a spindle in a cartridge case, a winding core that can move toward and away from the unwinding core, and a winding core that is rotatably attached to a spindle in a cartridge case. It consists of a driving rotating body for applying the winding drive. The drive single rotating body rotates while being in pressure contact with the outer peripheral surface of the ink ribbon wound around the winding core, thereby winding the ink ribbon around the winding core. The unwinding core is provided with resistance to its rotation and tension is applied to the ink ribbon to prevent the ink ribbon from becoming slack in the printing section.

[Problems to be Solved by the Invention] In conventional ink ribbon cartridges that provide rotational resistance to the unwinding core, as the ink ribbon is used more and more and the winding diameter of the unwinding core becomes smaller, the effect on the ink ribbon increases. As the tension increases, elongation occurs in the ink ribbon. Therefore, printing defects may occur at the end of the ink ribbon's use.

In order to prevent such printing defects from occurring, if the rotational resistance applied to the unwinding core is made small from the beginning, the ink ribbon will become sagging at the end of its use, which will also cause printing defects. .

As described above, in conventional ink ribbon cartridges, it is difficult to eliminate printing defects caused by elongation of the ink ribbon itself or sagging in the printing section.

In order to solve the above-mentioned problems, the present invention provides an ink ribbon cartridge configured to apply a uniform tension to the ink ribbon from the initial stage of use to the final stage of use of the ink ribbon. With the goal.

[Means for Solving the Problems] The ink ribbon cartridge of the present invention has an unwinding core that is rotatably and non-displaceably mounted in a cartridge case, and a side that is rotatable and can move toward and away from the unwinding core and that is away from the unwinding core. In the ink ribbon cartridge, a drive rotor is attached to the cartridge case, to which a take-up core is attached and which cooperates with the take-up core to nip the ink ribbon and drive the ink ribbon to be wound. The upper part of the winding core is attached to one end of a tension spring that presses the upper part of the winding core so as to be relatively rotatable but not relatively movable, and the upper part of the unwinding core is attached to the other end of the tension spring so that the upper part of the unwinding core can be relatively rotatable and relatively immovable. The tension is set such that as the upper part of the winding core approaches a fulcrum part that is slidably attached and that is provided between both ends and contacts the cartridge case, the holding force applied to the winding core is reduced. A configuration in which a spring is formed is adopted.

[Operation and Effects of the Invention] At the beginning of the ink ribbon's use, the winding diameter of the ink ribbon is large on the unwinding core side and small on the winding core side, but as the ink ribbon is used, the winding diameter of the unwinding core becomes smaller. The winding diameter of the winding core changes to become larger, and at the end of the ink ribbon's use, the winding diameter of the unwinding core becomes smaller and the winding diameter of the winding core becomes larger, which is exactly the opposite of the state at the beginning of use. There is.

Due to such a change in the winding diameter, the winding core gradually approaches the unwinding core from a distance, and since one end of the tension spring is attached to the winding core, the unwinding of the winding core is prevented. The tension spring moves as it approaches the core, and initially the tip of the other end of the tension spring was in contact with the upper surface of the unwinding core, but gradually the fulcrum part is displaced so that it is in contact with the upper surface of the core. Therefore, the pressing force exerted by the tension spring on the unwinding core, which was initially strong, is gradually and continuously reduced.

In this way, when the winding diameter of the unwinding core is large, the rotational resistance is large, and when the winding diameter is small, the rotational resistance is also small, so that the tension acting on the ink ribbon itself can be averaged.

However, in the present invention, since the ink ribbon does not stretch or sag, it is possible to eliminate printing defects caused by this.

[Example code] Next, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is an internal plan view of an ink ribbon cartridge according to an embodiment of the present invention, and FIGS. 2 and 3 are sectional views taken along the line (I)-it+x+ in FIG. It is a drawing explaining an effect|action.

In Figures 1 and 2, (1) is a box-shaped cartridge case body, which is made up of a ribbon storage section (2), a ribbon ejection arm (3), and a ribbon return arm (4), and is used for printers and other devices. When set in a typewriter, the ribbon passing path (5) between the tips of the two arms (3) and (4) faces the recording paper, and the ink ribbon (A ) is transferred onto the recording paper to form a printed image on the recording paper. (
6) is a lid serving as a top plate of the cartridge case, and is fitted onto the top surface of the case body (1). (The sword is an unwinding core, and is rotatably supported by a fixed shaft (8) erected at a location on the minus side of the ribbon storage section (2). (12) is a winding core, a cylindrical projection (14) is formed at its lower part, and a cylindrical projection (15) is formed at its upper part. It is formed.

Reference numeral (13) denotes a guide groove, which is formed at the bottom of the ribbon storage section (2) on the other side (the right side in the figure).

The winding core (12) has its protrusion (14) loosely fitted into the guide groove (13), and the winding core (12) has a position far away from the sword (shown in Figures 1 and 2) and an unwinding core (12). It is adapted to move and hang between a position (shown in Figure 3) close to the core ('7).

(18) is a drive rotating body, and the winding core (12)
) in the figure (that is, the part opposite to the side facing the unwinding core (71)), and is located on the right side in the figure of the winding core (
The ink ribbon (A) is rotated by an external drive while being pressed between the winding core (12) and the winding core (12).
Wind up the ink ribbon (A). Reference numeral (10) denotes a tension spring, which is shaped like a strip in plan view, and is bent at one place in the center so that the cross-sectional shape in the longitudinal direction is dogleg-shaped, and the bending point is used as a fulcrum part (17). And the tension spring (10) is on the right side in the figure (fully wound core (12)).
) side) is equipped with a biasing spring (20
) is formed on the left side in the figure (that is, the part on the unwinding core (71 side)) with a length approximately half the length of the tension spring (10). long hole (
11) is formed. And this tension spring (
10) has a small hole (16) at one end of the winding core (12).
) is inserted into and supported by the protrusion (15) of the lid (6), and the fulcrum portion (17) at the center is attached to resiliently abut against the back surface of the lid (6). Meanwhile, the tension spring (10)
The free end side of the long hole (11) is an unwinding core
) and is slidably contacted with the upper surface of the unwinding core (7). In this way, the tension spring (10) has a core (7), (
12) and the lid (6), so that the free end side elastically presses down the upper surface of the unwinding core (sword).
) is an iron spring with a protrusion (22) on the case body (1).
), and its free end is engaged with the protrusion (21) of the tension spring (10).

The winding core (12) is pressed against the driving rotary body (18) via the tension spring (10) by the elastic force of the biasing spring (20).

Next, the operation of the above embodiment will be explained. As shown in Fig. 2, when the ink ribbon (A) is first used, the ink ribbon (A) is not wound around the winding core (12), so the ink ribbon (A) is unwinded. Core (12)
The winding diameter is small and its position is on the right side in the figure. Therefore, the unwinding core (sword) is pressed by the tip of the tension spring (10), and strong rotational resistance is applied. At the end of the process, a large amount of the ink ribbon (A) is wound around the winding core (12), and as its winding diameter increases, the distance between it and the driving rotor (18) widens.
2) is gradually moved to the left side of the figure. When the winding diameter of the unwinding core (7) is reduced in this way, the unwinding core (sword) is pressed at a portion close to the fulcrum (17) of the tension spring (10), so a small rotational resistance is generated. It will be added.

As described above, since rotational resistance proportional to the winding diameter is applied to the unwinding core (7), the ink ribbon (A
), a tension that is neither too large nor too small is applied on average to the middle shrine during use. In this way, the occurrence of printing defects due to insufficient tension or excessive force is effectively prevented.

[Brief explanation of drawings]

FIG. 1 is an internal plan view of an ink ribbon cartridge according to an embodiment of the present invention, and FIGS. 2 and 3 are sectional views taken along the line (1)-(1) in FIG. It is a drawing explaining the action of the cartridge. (Main symbols in the drawing) (1): Cartridge case body (7): Unwinding core (10): Tension spring (12): Winding core (13): Guide groove (171: Support part (20): Included Force spring 1: Cartridge case body 7: Unwinding core 20: Force spring

Claims (1)

[Claims] 1. An unwinding core is installed in a cartridge case so as to be rotatable and non-displaceable, and a winding core is installed so as to be rotatable and capable of moving toward and away from the unwinding core, and is urged to move away from the unwinding core. In an ink ribbon cartridge in which a driving rotating body is attached to the cartridge case for cooperating to nip and drive the ink ribbon to take it up, one end of a tension spring that presses the tops of both cores has an upper part of the take-up core. is relatively rotatably and relatively immovably attached, the upper part of the unwinding core is relatively rotatably and relatively slidably attached to the other end of the tension spring, and the cartridge is provided between both ends. An ink ribbon cartridge, wherein the tension spring is formed so as to reduce the pressing force applied to the take-up core as the upper part of the take-up core approaches the fulcrum part that contacts the case.