JPS6243179B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant gap maintaining device for a working body mainly used in the recording section structure of an image information printer.

In the structure of a conventional printer recording section, as shown in FIG. 1, a dielectric drum D as a rotating body;
A pin electrode P is provided as a longitudinal effecting body disposed opposite to the width line of the circumferential surface of the drum D. Based on the action of an electric field, an information image is deposited and recorded using a toner developer.

In another method, an electrostatic charge pattern is formed on a dielectric material using a pin electrode P, and the pattern is recorded through development, transfer, and fixing steps. In this method as well, there is a method in which a gap is provided between the pin electrode P and the dielectric material as in the above-mentioned method. Of course, in this method, the toner remaining on the surface of the dielectric material after transfer is removed by a static elimination and cleaning process, and the dielectric material is made ready for re-recording.

However, if the size of the gap C changes during the rotation of the drum D, it will cause a decrease in the quality of the recorded image, so it is structurally important to always keep the gap C at a constant size. In this respect, in the conventional constant gap maintaining device shown in the figure, a pair of rollers 2 pivotally supported by an ear shaft 1 at the lower end of the electrode P is pressed and biased by a compression spring 3 to close the side end of the drum D. The guide ring 4 is brought into contact with and slid on the guide ring 4, thereby keeping the gap C constant.

However, in such a conventional constant gap maintaining device, foreign matter such as toner or dust is likely to intervene on the contact surface between the roller 2 and the ring 4, and as a result of foreign matter intervention, a problem occurs in which the gap C fluctuates. This also caused problems such as backlash and eccentricity of the roller 2, which affected the gap size.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to maintain a constant gap size between a rotary working body and a contact working body accurately and reliably. An object of the present invention is to provide a gap retaining device.

The present invention will be described below based on illustrated embodiments.

First, in the first constant gap maintaining device, as shown in FIGS. 3 to 5, the guide drum 5 as a rotary operating body has a cylinder 6A connected to a drum shaft 8 via two disks 7. The inner wall surface 6Aa serving as the rotation reference surface near the left and right ends of the cylinder 6A has an annular groove 6 into which the ball 9 is fitted.
A is drilled.

On the other hand, the pin electrode 10 as a working body has a cylinder 6
It has the shape of a thick plate with approximately the same width as A, and its lower edge with a semicircular cross section is in contact with the generatrix of the outer peripheral surface of the cylinder 6A, and on each left and right side of the lower edge,
A pair of U-shaped arm members 11 are fixed.

This arm member 11 includes an ear portion 11a that projects laterally from the pin electrode 10, and a folded portion 11C at the tip.
and a key portion 11b which is inserted along the inner circumferential surface 6Aa of the cylinder 6A, are integrally formed,
A ball 9 is fitted into a hemispherical recess formed in the folded portion 11C.

Further, the pin electrode 10 is pulled up and biased by two extension springs 13 stretched between it and the immovable part 12, and therefore the deposited part 1 of the key part 11b
1C is the annular groove 6 of the dielectric drum 5 via the ball 9.
It is in pressure contact with a.

According to the holding device configured in this way, since the contact portion between the arm member 11 and the cylinder 6A is hidden inside the drum 5, foreign matter does not enter the contact portion, and therefore, the pin electrode 10 is prevented from entering the contact portion. The gap size is precisely maintained at a fixed size, and even if the operating time is accumulated, the holding accuracy will not deteriorate.

The contact portion between the arm member key portion and the drum cylinder may be formed as shown in FIGS. 6 to 10 below instead of the above-described structure, and the same operation and effect can be obtained.

(a) An inner wall surface 6Ba (FIG. 6) serving as a rotational reference surface for the key portion 11b and the cylinder 6B has a structure in which a ball 9 is fitted into an annular shape 6b having a triangular cross section.

(b) Inner wall surface 6Ca (FIG. 7) serving as a rotational reference surface for the lock portion 11b and the cylinder 6C.The ball 9 is fitted into an annular groove 6c having a dish-shaped cross section.

(c) Inner wall surface 6Da that is the rotation reference surface of the key part 11b and the cylinder 6D (Fig. 8) Cylinder 6D without an annular groove
It has a structure in which the ball 9 is brought into contact with the smooth surface of the ball.

(d) Key part 11c and cylinder 6A (Fig. 9) Key part 1
The base end of the folded portion 1c is made thin.

(e) Key part 11c, cylinder 6A and collar 14 (10th
Figure) In addition to being formed in the same manner as in the previous section, the cylinder 6A has a structure in which a dust-proof collar 14 is fixed to the side end of the cylinder 6A.

In addition, the said collar may be provided protrudingly on the key part 11c side, and the shape of the collar may be, for example, like a ring gear described later.

Furthermore, similar operations and effects can be obtained even if the structure is formed as shown in FIGS. 11 to 14 below.

(a) Key part 11d and cylinder 6D (Figs. 11 and 12)
Figure) The upper surface of the tip of the key portion 11d is formed into a curved portion, and the curved surface is directly brought into contact with the inner wall surface 6Da, which is the rotation reference surface of the cylinder 6D.

(b) Inner circumferential surface 6Da, which is the rotational reference plane of the key part 11e and the cylinder 6D (Fig. 13), has a structure in which the cross-sectional shape of the key part 11e is formed into a boat-bottom shape, and is brought into contact with the cylinder 6D in the same way. do.

(c) Key part 11f and cylinder 6D (FIG. 14) The cross-sectional shape of the tip of the key part 11e is formed into a circular shape, and the structure is made such that the key part 11e is similarly brought into contact with the cylinder 6D.

Although not shown in the drawings, a similar operation can be obtained by a structure in which a roller is pivotally supported at the tip of the arm member key portion and the roller is brought into contact with the inner peripheral surface 6Da of the cylinder 6D.

In addition, as shown in FIG. 15, in the case of an induction drum formed in such a manner that an internal gear 15 is fixed to the side end of the cylinder 6D and the cylinder 6D is driven by a pinion 16 meshed with the gear 15, , arm member 11c
(already described), no special dust-proofing means are required.

Next, instead of bringing the arm member into contact with the inner circumferential surface of the cylinder, a tapered surface may be formed on the end of the cylinder, and the arm member may be held by the tapered surface. Specifically, As shown in FIG. 16, the ball 9 fitted in the arm member key portion 11g is
A structure in which the cylinder 6E is brought into contact with a tapered surface 6d serving as a rotational reference surface, or as shown in FIG. 14,
A structure in which the roller 17 supported by the key member 11H is brought into contact with the tapered surface 6d, or as shown in FIG. A structure in which they are in contact with each other can be used.

In this way, when the arm member is held by the tapered surface of the cylinder, only the vector amount of the amount of wobbling at the contact portion affects the gap size, so the gap size can be maintained even better. .

Next, in the constant gap maintaining device according to the second embodiment method, as shown in FIGS. 19 and 20, L
A ball 9 is fitted into the inner surface of the lower end of the arm member 18A, and an annular groove 6c into which the ball 9 is fitted is bored in the side end surface 6Fa, which is the rotation reference surface of the cylinder 6F. In this holding device, the arm member 18 and the cylinder 6 are held together by compression springs 19 from both sides.
Even if foreign matter gets into the contact part of F, that is, the fitting surface of the ball 9, it will only cause rattling in the left and right directions of the contact part, and will not affect the gap size of the pin electrode 10. Therefore, the size of the gap is precisely maintained at a fixed size, and no deterioration occurs over time.

The contact portion between the arm member and the cylinder may be formed as shown in FIGS. 21 to 23 below instead of the above-described structure, and the same operation and effect can be obtained.

(a) Arm member 18A and cylinder 6G (FIG. 21) The annular groove 6f of the end surface 6Ga of the cylinder 6G into which the ball 9 is fitted is formed with a groove having a triangular cross section.

(b) Arm member 18A and cylinder 6H (FIG. 22) The annular groove 6g of the end surface 6Ha on the side of the cylinder 6H has a cross-sectional shape shaped like a dish.

(c) Arm member 18B and cylinder 6J (Fig. 23) The side end surface 6Ja, which is the rotational reference surface of cylinder 6J, is formed to have a chevron-shaped cross section, and opposing recesses with triangular cross-section are bored in the arm member 18B, and the same concave part 2
It has a structure in which one small diameter ball 20 is fitted on each surface.

As described above, according to the constant gap maintaining device according to the present invention, a longitudinal effecting body is passed between a pair of arm members and fixed thereto, and the end portions of the arm members are brought into contact with each other by the effecting body. side end surface of the rotary operating body;
or make it come into contact with the inner wall surface near the side edge with elastic pressure,
As a result, the acting body is joined to the working body, so
This has the effect of improving the reliability of the holding device, such as making it possible to accurately and reliably hold the contact gap between the working bodies at a fixed size without causing any deterioration in the holding performance.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the printer recording section, FIG. 2 is a side view of FIG. 1, FIG. 3 is a front view of a constant gap maintaining device showing the first embodiment of the present invention, and FIG. 4 is a side view of FIG. 3, FIG. 5 is an enlarged view of the main part of FIG. 4, FIGS. 6 to 10 are approximate structure diagrams of the main part of FIG. 3, and FIG. 5 is a diagram of the approximate structure, FIG. 12 is a sectional view of FIG. 11, FIGS. 13 and 14 are diagrams of the approximate structure of FIG.
Figure 5 is a diagram showing an application example of Figure 3, and Figure 16 is a diagram showing an application example of Figure 3.
The approximate structure in FIG. 3, FIGS. 17 and 18 are enlarged views of the approximate structure of the main parts in FIG. 16, and FIG.
The figure is a front view of the constant gap holding device showing the second embodiment, FIG. 20 is a side view of FIG. 19, and FIGS. 21 to 23 are approximate structures of the main parts of FIG. 19. It is an enlarged view. 5... Inductive drum as a rotary working body, 10...
...Pin electrode as a longitudinal effect body, 11, 18A,
18B...Arm member, 6Aa, 6Ba, 6Ca, 6
Da...inner wall surface, 6Fa, 6Ga, 6Ha...side end surface,
13,19...Spring.

Claims (1)

[Scope of Claims] 1. A constant gap holding device that supports a longitudinal effecting body arranged along the generatrix of a cylindrical rotary working body while maintaining a constant gap from the outer peripheral surface of the rotary working body, Either end surfaces of the cylindrical rotary actuating body or inner wall surfaces near both ends, which serve as a reference surface for keeping the longitudinal effecting body at a constant position with respect to the cylindrical rotary actuating body. a rotational reference surface, and each provided on both sides of the cylindrical rotary working body, each one end being fixed to the longitudinal working body;
A constant gap maintaining device comprising: an arm member whose respective other ends slide against the rotation reference surface; and a biasing means which urges the respective other ends in a direction to cause the respective other ends to slide against the rotation reference surface.