GB2030549A

GB2030549A - Feeding roller assembly

Info

Publication number: GB2030549A
Application number: GB7930894A
Authority: GB
Original assignee: Dainippon Screen Manufacturing Co Ltd
Current assignee: Dainippon Screen Manufacturing Co Ltd
Priority date: 1978-09-19
Filing date: 1979-09-06
Publication date: 1980-04-10
Also published as: JPS6016913Y2; JPS5547064U; FR2436733B1; DE2937387A1; FR2436733A1; GB2030549B

Abstract

In a film conveyor which comprises at least one drive roller (2), there is provided an idling roller (10) which is to be held by its own weight against the drive roller so as to co-rotate along with it. The ends of the drive roller are rotatably mounted to the first ends of two arms, and the second ends of these two arms are pivotally mounted to the body of the conveyer. By pivoting the arms relative to the body of the conveyor the idling roller may be moved between a first position wherein it rests against the drive roller and a second position wherein it is away therefrom so as to leave it unencumbered, for cleaning or the like. <IMAGE>

Description

SPECIFICATION An idling roller assembly for a film conveyer This invention relates to a film conveyer, and in particular relates to a film conveyer for, for example, an automatic film developer, which is well adapted to convey relatively wide films.

Film developers are well known, in which film is conveyed automatically through a developing tank, a fixing tank, a washing tank, etc. . The conveyers in such developers conventionally comprise a plurality of drive rollers which convey the film, sometimes in co-operation with guide plates.

A problem has arisen connected with the width of the film to be developed. When this film is wider than, say, 1 meter, the rollers also have to be correspondingly long (at least as long as the film), and hence there is a tendency for them to sag in the middle due to their own weight, since they are only supported at their ends. Even a small degree of sag can mean pressure variation along the length of the film which is being processed, and since such film is rather sensitive to pressure uneven development can thereby occur. It has generally therefore been regarded as rather difficu It to build a roller conveyer system for successfully processing wide film.

A conveyer such as proposed in Japanese Patent Publication No. 48-32132 is effective for overcoming this problem. Fig. 1 is a cross-sectional view for explaining this prior art. 1, 1 are roller guide supports fixed to the wall of a developing tank. 2 is a drive roller which drives the film, and is at least partially submerged in developing liquid. This roller 2 (of which two are shown in the drawing) is pivoted and horizontally supported by the walls the the tank, and it rotates as shown by the arrow. 3,3 denote idling rollers which are mounted in slots 5 in the roller guide supports 1, and which are pressed by their own weight against the drive roller 2, since the slots 5 angle downward and inward, as shown in the drawing. 6 denotes a spray tube, 7 and 8 are guide plates, and 9 is the film which is being processed.

In this conveyer the main drive roller 2 is formed as shown in Fig. 2; that is, it is hollow and its ends are sealed, so that it is filled with air. Thereby, the buoyancy generated along its length tends to support it, so that it does not sag. The idling rollers 3 are also formed in this way, but their weight and dimensions are adjusted so that they tend to sink in the liquid filling the tank, thus ensuring that they are pressed by the action of this sinking force against the drive roller 2. Typically, the pressing force may amount to about half the weight of the idling rollers.

4 denotes the ends of the idling rollers, which are formed into shafts which are engaged in the slots 5.

This kind of conveyer is well adapted to process wide pieces of film, but is difficu It to maintain and inspect. The removal of the idling and drive rollers for washing, for example, is very time-consuming.

The present invention has as its object the provision of a film conveyer for wide film which is not so inconvenient as the above-outlined prior art.

According to the present invention, this object and others are attained by, in a film conveyer which comprises a body and a drive roller which drives film through the conveyer and is mounted in the body along a generally horizontal axis pivotally by its two ends so as to be rotatable around said axis, an idling roller assembly, comprising an idling roller pivotable about its axis and extending generally parallel to the drive roller, and two arms, each of which extends in a direction oblique to the axis of the idling roller, and is pivoted at its one end to one end of the idling roller and at its other end to the body, the idling roller, by the pivoting of each of the arms relative to the body, being movable between a first position wherein it rests against the drive roller and follows its rotation and is kept in lengthwise contact therewith by the action of gravity, and a second position wherein it has been pivoted away therefrom so as to leave the drive roller unencumbered by it.

The present invention will become more fully understood from the following description of several preferred embodiments thereof, and from the accompanying drawings, which, however, are not to be taken as limitative of the present invention in any way, but are given for the purposes of illustration and exemplification only. In the drawings: Fig. 1 is a cross-sectional view of a prior art film conveyer; Fig. 2 is a partial cross-sectional view of a drive roller in the conveyer of Fig. 1; Fig. 3 is a cross-sectiona I view of a film conveyer which incorporates an idling roller assembly which is an embodiment of the present invention; Fig. 4 is a perspective view of the idling roller assembly of Fig. 3; and Fig. 5 is view similar to Fig. 3, showing some of the idling roller assemblies pivoted to their second positions.

Referring to Figs. 3 - 5, the idling rollers 10, which are similar to the idling rollers of the prior art, are each mounted to a pair of arms 12 by their shafts 11, so as to be rotatable about their axes. The arms 12 extend at an oblique angle to the axes of the rollers 11 (typically at right angles), and the other ends of the arms 12 are pivoted, via shafts 13, to the body of the film conveyer (which is not shown). The numerals 2 designate drive rollers, and the numerals 14 and 15 designate guide plates for the film. As before, 6 are spray tubes, and 9 is a film passing through the conveyer.

Referring particularly to Fig. 5, the idling rollers on the left hand side of the drawing are shown by phantom lines in their first positions where they rest against the drive rollers and follow the rotation of the drive rollers, by the action of gravity. On the other hand, these idling rollers are shown by the solid lines in their second positions, wherein they are pivoted away from the drive rollers so as to leave them unencumbered, for washing or the like. This pivoting is accomplished by moving each of the arms supporting the idling roller relative to the body of the conveyer.

The idling roller at the top in Fig. 5 (atthe left hand side) is arranged differently from the others. All of the rollers, when in their first positions, are maintained therein by the action of gravity, which presses them against their respective drive rollers. However, the top roller in Fig. 5, when it is in its second position, is also kept therein by the action of gravity; this is because its first and its second position lie on opposite sides of a vertical plane drawn through the ends of its arms which are pivoted to the body. As for the lower rollers, when they are pivoted to their second positions, they are held therein by catches which are not shown in the drawing.

By the arrangement for supporting the idling rollers, according to the present invention, a significant improvement is attained over the described prior art, and it is much easier to inspect and clean the rollers of such a film conveyer. The present invention has been described in terms of several preferred embodiments thereof, but it should not be considered as limited to these, however, or mere and simple generalizations, or other detailed embodiments; yet further alterations and variations of the form and the details of any particular embodiment might be made therein, without departing from the spirit of the present invention.

For example, in the shown embodiment the idling rollers and their mounting structures are provided in pairs, each drive roller being mounted between the two idling rollers of a pair. However, although this is a preferred construction, it is not essential to the present invention.

Claims

1. In a film conveyer which comprises a body and a drive roller which drives film through the conveyer and is mounted in the body along a generally horizontal axis pivotally by its two ends so as to be rotatable around said axis: an idling roller assembly, comprising: an idling roller pivotable about its axis and extending generally parallel to the drive roller; and two arms, each of which extends in a direction oblique to the axis of the idling roller, and is pivoted at its one end to one end of the idling roller and at its other end to the body; the idling roller, by the pivoting of each of the arms relative to the body, being movable between a first position wherein it rests against the drive roller and follows its rotation and is kept in lengthwise contact therewith by the action of gravity, and a second position wherein it has been pivoted away therefrom so asto leave the drive roller unencumbered by it.

2. In a film conveyer which comprises a body and a drive roller which drives film through the conveyer and is mounted in the body along a generally horizontal axis pivotally by its two ends so as to be rotatable around said axis: an idling roller assembly, comprising two idling rol lersubassemblies, each of which comprises: an idling roller pivotable about its axis and extending generally parallel to the drive roller; and two arms, each of which extends in a direction oblique to the axis of the idling roller, and is pivoted at its one end to one end of the idling roller and at its other end to the body; the idling roller, by the pivoting of each of the arms relative to the body, being movable between a first position wherein it rests against the drive roller and follows its rotation and is kept in lengthwise contact therewith by the action of gravity, and a second position wherein it has been pivoted away therefrom so as to leave the drive roller unencumbered by it; wherein, when the idling rollers are each in its first position, they lie on opposite sides of a vertical plane through the axis of the drive roller.

3. An idling roller assembly according to claim 1 or claim 2, wherein, when every said idling roller is in its second position, it is kept therein by the action of gravity.

4. An idling roller assembly according to claim 1 or claim 2, further comprising for every said idling roller a catch which operates to maintain it in its second position.

5. An idling roller assembly according to claim 1 or claim 2, wherein for every said idling roller its first position and its second position lie on opposite sides of a vertical plane drawn through the ends of the arms which are attached to that idling roller which are pivoted to the body.

6. An idling roller assembly according to claim 1 or claim 2, wherein for every said idling roller its first position and its second position lie on the same side of a vertical plane drawn through the ends of the arms which are attached to that idling roller which are pivoted to the body, and further comprising, for every said idling roller, a catch which operates to maintain it in its second position.

7. In a film conveyer comprising at least one drive roller, an idling roller assembly constructed, arranged and adapted for use substantially as hereinbefore described with reference to Figures 3 to 5 of the accompanying drawings.