GB2108706A - Film processor - Google Patents

Abstract

A film processor comprises a pair of wheels (1, 2) located one above the other, an endless drive member (3) passing around both wheels, and means for driving at least one of the wheels. A bar arrangement (4) has means for carrying a film-receiving hanger (6). A lever (13) is pivotally connected at one of its ends (15) to the bar arrangement (13), pivotally connected at its other end (14) to the endless drive member (3), and pivotally connected at a point (16) intermediate its ends to a vertically reciprocatable plate (7). Movement of the endless drive member (3) causes the bar arrangement (4) to reciprocate both vertically and horizontally, thus moving film hangers 6 releasably carried by the bar 4 progressively through treatment baths. <IMAGE>

Description

SPECIFICATION Film processor This invention relates to a film processor.

Processors are known which are of the so-called dip-and-dunk type. In such processors hangers carrying the films to be processed are dipped in a succession of baths, the raising and lowering of the hangers which is necessary for this being carried out by mechanical means, The successive baths are located side by side which means that a hanger being transferred from one bath to the next must successively be lifted from the first bath, moved sideways to locate it over the second bath, and then lowered into that second bath.

In a known dip-and-dunk machine lifting and lowering of the hangers and their sideways movement are produced by a pair of bars which are secured to an endless chain passing around two sprocket wheels located one above the other and from which the hangers are freely suspended.

One of the sprocket wheels is driven by an electrical motor. When the motor is in operation the bars are caused to move up and down and also to reciprocate laterally. By appropriate means this lateral movement is used to cause movement of the hangers in a single lateral direction in order to move them from one bath to the next.

It is desirable to transfer the films being processed from one bath to the next as quickly as possible. The desirability of this arises from the need to reduce the amount of time for which the films are exposed to the air and also the need to reduce the difference in the times for which different portions of the films being processed are in each bath. It will be appreciated that portions of the films nearer the lower end of the hanger are in the bath for longer than portions of the films nearer the upper end of the hanger, and this difference is accentuated if the films are moved into and out of the baths only slowly. However, as noted above, the hangers are suspended freely from the above mentioned bars while they are being transferred from one bath to the next.If the hangers are moved too quickly during the portion of time in which they are being moved laterally this causes the hangers to swing, and this can give rise to serious difficulties, such as, for example, the hanger entering the wrong bath when it is lowered or becoming jammed against the dividing wall between two adjacent baths. In known machines, therefore, the electric motor mentioned above is a two-speed motor, its slower speed being used while the hangers are moving laterally, and its faster speed being used for the rest of the time.

However, the use of a two-speed motor does itself give rise to problems, such motors and their associated control circuitry being expensive and inclined to be unreliable.

It might be thought that the problem could be dealt with by suspending the hangers rigidly rather than allowing them freedom of pivotal movement.

In practice, however, no satisfactory way of fixing the hangers rigidly has been found. Nor is it possible to overcome the problems simply by making the baths narrower, thereby reducing the distance through which the hangers have to be moved laterally. An adequate clearance must be left between the films being processed and the walls of the baths.

Our prior patent application publication GB 2043490A provides a film processor comprising a pair of wheels located one above the other; an endless drive member passing around both wheels; means for driving at least one of the wheels; a first bar arrangement mounted for reciprocating vertical movement; a second bar arrangement extending parallel to the first bar arrangement; a lever pivotally connected at one of its ends to the said first bar arrangement, pivotally connected at a point intermediate its ends to the second bar arrangement and pivotally connected at its other end to the said endless drive member; and means on the said second bar arrangement for carrying a film-receiving hanger, whereby movement of this endless drive member causes the second bar arrangement to reciprocate both vertically and horizontally.

The film processor described in Publication GB2043490A has distinct advantages over previously known dip-and-dunk processors.

Neverthless, there are two particular respects in which it has been found to be not entirely satisfactory. The first of these is that the machine is very tall, which makes packing and transport difficult and expensive. The only way of avoiding this would be for the machine to be packed and transported in a substantially disassembled form and then assembled on site, but is clearly much less convenient than transporting it to a customer in substantially assembled form. It is an object of one aspect of the invention to provide an improved film processor of the dip-and-dunk type in which this disadvantage is overcome.

The second aspect in which the processor of Publication GB2043490A has been found not to be entirely satisfactory arises from the fact that, in the described embodiment, two chains are used.

The reason for using two chains was to keep adequate squareness of the bar arrangements as they were being driven up and down, but it has been found difficult to align the two chains with one another. Although this problem can be overcome by using adjustable sprockets, this adds additional cost and complexity to the processor. It is an object of a second aspect of the invention to deal with this problem.

According to a first aspect of the invention there is provided a film processor comprising a pair of wheels located one above the other; an endless drive member passing around both wheels, means for driving at least one of the wheels; a bar arrangement having means for carrying a film-receiving hanger; and a lever pivotally connected at one of its ends to the bar arrangement, pivotally connected at its other end to the endless drive member, and pivotally connected at a point intermediate its ends to a vertically reciprocable member, whereby movement of the endless drive member causes the bar arrangement to reciprocate both vertically and horizontally.

As will become apparent from the ensuing description with reference to the drawing, such a film processor can be so constructed as to be capable of being easily disassembled into two parts for packing and transport and then easily reassembled.

According to a second aspect of the invention there is provided a film processor comprising a pair of wheels located one above the other; an endless drive member passing around both wheels; a bar arrangement having means for carrying a film-receiving hanger; a lever pivotally connected at a first point to the bar arrangement, pivotally connected at a third point to a member arranged for vertical reciprocating movement, the distance from the first point to the third point being less than the distance from the second point to the third point; and means for guiding the vertical reciprocating movement of the vertically reciprocating member.

An example of a device embodying both aspects of the invention is shown in the accompanying drawing.

This shows a pair of sprocket wheels 1 and 2 around which an endless chain 3 passes. At least one of the sprocket wheels is driven by a singlespeed electric motor (not shown), preferably the sprocket wheel 2. The processor has a pair of horizontally disposed bars 4 (only one of the bars is shown, the other being behind that illustrated), and the bars are provided with notches 5 which receive the upper ends of film-receiving hangers 6.

One of these hangers is shown in the drawing. The bars 4 are mounted for horizontal reciprocating movement on a plate 7. The plate 7 is arranged to be vertically reciprocatable in a pair of vertically extending U-section members 8. The plate 7 is guided in the members 8 by four arrangements of guide rollers 9, one arrangement of rollers at each corner, and part of one of the guide members 8 is broken away to show one of these arrangements.

This comprises a pair of rollers 10, one of which can be seen face on, which bear against the base of the U, and a single roller 11 which can be seen end on, which bears against one of the side walls of the U.

A lever 1 3 interconnects the endless chain 3 and bars 4. One end of the lever 13 is connected to the endless chain 3 by a pivotal connection 14.

The other end of the lever 13 is connected by a pivotal connection, denoted by numeral 15, to a framework which includes the bars 4 and cross members (not shown) which extend between the bars 4, and is thus effectively connected to the bars themselves. An intermediate point on the lever 13 is connected by a pivot 1 6 to the plate 7.

The weight of the plate 7 is counterbalanced by an arrangement which includes a cord 17 attached at one end to a point 20 intermediate the pivots 14 and 1 6. The cord passes over a pulley 18 and then over a second pulley (not shown) to a counterweight.

Operation of the processor is as follows. As the sprocket wheels rotate the chain 3 moves so that the pivotal connection 14 travels in a downward direction. This causes the plate 7 and the bars 4 to move downwards, the bars 4 carrying with them the hanger 6. When the hanger 6 has descended a sufficient distance the films thereon enter a respective one of the baths of the processor, the upper level of the baths being denoted diagrammatically in the drawing by a broken line 1 9. As the hanger 6 continues to travel downwardly the upper end thereof, which hitherto has been resting in a pair of respective notches 5, engages a fixed carrier (not shown) positioned adjacent the baths, and further downward movement of the bars 4 takes them out of contact with the hanger 6.At this point in the operation the motor is automatically stopped and the films on the hanger are ieft in the baths for a predetermined length of time. When this time has elapsed the motor is restarted and the pivotal connection 1 4 passes around the lower sprocket wheel 2. Because of the presence of the lever 13 the bars 4 are caused to move laterally in a rightwards direction. This brings another notch 5 below the upper portion of the hanger 6 and continued movement of the chain 3 causes this further notch to engage the hanger 6 and lift it upwardly and out of the bath. When the pivotal connection 14 reaches the upper sprocket wheel 1 it travels around that wheel and thus causes the bars 4 with its notches 5 and hanger 6 to move leftwardly.It shouid be noted that the amount of leftward movement of the bars 4 is less than the diameter of the sprocket wheel 1 , the difference depending on the lever ratio of the lever 1 3.

It is to be noted that in addition to counterbalancing the weight of the plate 7 the counterweight arrangement described above also has the effect of urging the chain 3 outwardly.

This is useful since for guide purposes it is necessary to provide a guide plate between the sprocket wheels 1 and 2, and in the absence of the above mentioned effect the chain would tend to rub on that plate, thus causing wear. The lever 1 3 has stops to prevent it moving too far outwards, and so taking outside a vertical line between the pitch circles of the sprockets.

The film processor described above can readily be made so that it can be quickly disassembled into two parts and quickly re-assembled. When the plate 7 is in the lower position, all that remains above the sprocket wheel 1 is the counterweight arrangement (which can easily be disconnected), and members 8 and another pair of vertical members (not shown) which lie in front of the members 8 and which serve to support the front of the machine. If those other members are made to be detached at their lower ends of the rest of the machine, and the members 8 are made in two sections joined in the region of the top of the sprocket wheel 1, the whole of the machine above the sprocket wheel 1 can be detached preferably as a single unit, and the height of the machine is thus much reduced.

It is also to be noted that the processor employs only a single chain, rather than the two chains employed in the embodiment described in Publication GB 2043490A, so that the alignment problem mentioned above does not arise.

Claims (12)

1. A film processor comprising a pair of wheels located one above the other; an endless drive member passing around both wheels; means for driving at least one of the wheels; a bar arrangement having means for carrying a filmreceiving hanger; and a lever pivotally connected at one of its ends to the bar arrangement, pivotally connected at its other end to the endless drive member, and pivotally connected at a point intermediate its ends to a vertically reciprocatable member, whereby movement of the endless drive member causes the bar arrangement to reciprocate both vertically and horizontally.

2. A film processor according to claim 1, comprising means for guiding the vertical reciprocating movement of the vertically reciprocating member.

3. A film processor according to claim 2, wherein the vertical reciprocating member is a plate.

4. A film processor according to claim 3, wherein the plate is guided by a pair of vertically extending members.

5. A film processor according to claim 4, wherein the vertically extending members are U-section members and the plate is guided therein by a plurality of rollers.

6. A film processor according to any one of claims 2 to 5, which comprises a single pair of wheels and a single endless drive member.

7. A film processor according to any one of claims 2 to 6, which is arranged for ready disassembling into substantially two parts, one part being formed by a portion of the processor located above the upper one of the pair of wheels, and the other part being formed by a portion of the machine from the said upper wheel downwards.

8. A film processor according to any one of claims 1 to 7, wherein the weight of the vertically reciprocatable member is counterbalanced.

9. A film processor according to claim 8, wherein counterbalancing is provided by a member which exerts an upward force on the said lever at a location intermediate the points at which it is connected to the endless drive member and the vertically reciprocatable member.

10. A film processor according to any preceding claim which is arranged to be readily capable of disassembly into two parts, one of which consists of substantially all the components located above the upper wheel and the other of which consists of substantially all the remaining components.

11. A film processor comprising a single pair of wheels located one above the other; a single endless drive member passing around both wheels; a bar arrangement having means forcarrying a film-receiving hanger; a lever pivotally connected at a first point to the bar arrangement, pivotally connected at a second point to the endless drive member and pivotally connected at a third point to a member arranged for vertical reciprocating movement, the distance from the first point to the third point being less than the distance from the second point to the third point; and means for guiding the vertical reciprocating movement of the vertically reciprocating member.

12. A film processor substantially as herein described with reference to the accompanying drawing.