PHOTOGRAPHIC PROCESSOR AND CLIP

Abstract: A processor for photographic prints comprises a pair of slotlike tanks (13, 14) for holding processing chemicals for immersion of the prints. The tanks have V-shaped tops and lie on opposite sides of a common heating core in the form of a water-filled compartment (15) containing a heater and thermostat unit (18). In order to prevent the prints from sticking to the tank walls the walls are provided with a textured finish. Each print is held by a clip comprising a clip body (24) having a pair of jaws (29, 30) one of which carries biting means (31). The resilience of the body biasses the jaws together so that biting means (31) closes against a rigid support surface (32) carried by the other jaw. The jaws are moved apart by a wedge (37) carried by a plunger (25). A doctor blade (16) located above the central compartment (15) removes chemical from the print as it is removed from the tank.

Description: PHOTOGRAPHIC PROCESSOR AND CLIP The development of exposed photographic prints involves immersing them in various chemicals for specified periods of time, the chemicals being heated above ambient temperature. These chemicals are prone to oxidise rapidly on exposure to air (often ωithin one hour) and it has previously been proposed to use them in narrow heated tanks to keep the exposed area to a minimum. * This can increase the useful life of the chemicals to several months. It also reduces the volume of chemical which has to be heated, so cutting down warm-up time. There is also a further advantage in that the escape of toxic vapours is reduced. There is, however, a major drawback ωith the use o f a narrow tank, namely that the print has to be held in a special frame in order to stop the print from sticking to the tank sides, When the frame is removed from the tank it tends to carry a considerable amount of chemical with it so that in order to prevent contamination o f the next chemical in the process the print and frame must first be dipped in a stop bath or rinse. The present invention arises from the notion that if the print frame could be eliminated, the processing time could be _ QUVl significantly reduced, the stop bath could be done away with, and the tanks could be made even narrower. Now, the present invention provides apparatus for processing photographic printsj comprising a tank for holding processing chemicals for immersion of prints, in which the interior surface of the tank that might otherwise adhere to the prints is provided with a textured finish whereby such adhesion is prevented. It has been found that by using such a finish the previous problem of adhesion can be completely eliminated and the volume of the tank can be further rediced by at least half. Ulhilst it is envisaged that many different forms of textured finish could be used ( bumps, ridges, grooves, pits etc.) the finish preferably incorporates surface indentations. There are preferably between 1 and 100 such indentations per square cm. The invention also provides apparatus for processing photographic prints comprising a pair of slot-like tanks for holding processing chemicals for immersion of prints, the tanks being disposed on opposite sides of a common heating core with which they are in thermal conducting relationship. The slot-like nature of the tanks and their disposition relative to the core enables then to rapidly attain the required working temperature. The tanks are preferably provided ωith stop members at opposite ends of the slots and projecting from the side of the tank remote from the heating core. The invention further provides a clip (which may form part of the apparatus or a separate item of commerce) comprising a pair of jaws one of which carries biting means, the jaws being biassed OMP togethβr.- so that the biting means closes against a rigid support surface carried by the other j aw, and means for moving the jaws apart. The biting means may be a blade, or preferably teeth, two teeth being preferred. A preferred embodiment o f the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view o f a print processor in accordance ωith the invention, Figure 2 is a transverse section through the processor, Figure 3 is an enlarged de tail of the processor, Figure 4 is an end view o f a print clip for use with the processor, Figure 5 is a side view o f the clip , and Fi gures 6 a to f are various schematic representations o f the processor and clip illustrating hoω they may be used. Re ferring to Fig. s 1 and 2, the processor comprises a rectangular base 1 provided ωith rubber feet 2. Upstanding from and integral with the base are two trapezoidal end walls 3, 4, o f substantially identical shape. Four further walls 5 - 8 are cemented into grooves 9 - 12 in the base 1 and end walls 3, 4, to form two slot-like processing tanks 13, 14 , each o f about 1 litre capacity, separated by a central heating compartment 15. The upper edge portions 5a - 8a_ o f the tank walls are turned outwardly to provide the tanks with U-shaped tops. The top edges o f the outer tank walls 5, 8, are inset from the converging edges 3a, 3 and 4a, 4b of the OMPI , IPO walls 3 and 4, the reason for which will be revealed below. The central compartment 15 is closed by a top member 16 containing a hole 17. An electrical heater and adjustable thermostat unit 18 is inserted into the lower part of compartment 15 through one of the end walls 4. The processing tanks 13, 14, have drainage taps 19, 20, also inserted through the lower part of end wall 4. The inner faces of the tank walls 5 — 8 have textured surfaces (Fig. 3) formed by two sets of parallel ridges 21, 22, which intersect to create tβtrahedral indentations 23. The ridges are about 3*7 mm apart giving about 9 indentations per square cm. The clip shown in Fig.s 4 and 5 is formed of an integral plastics or stainless steel body 24 and a plunger 25. The body includes a flat square top part 26, opposed edges of which lead into under- turned sloping shoulders 27, 28, which in turn lead into a pair of opposed downwardly directed jaws 29, 30. One of the jaws 30 carries a pair of spike-like teeth 31 directed towards a flat, rigid support surface 32 provided by a downward extension of the opposed jaw 29. The inherent resilience of the clip body biasses the jaws together so that the teeth 31 close against the surface 32. The jaw 29 also carries a stop member 33 positioned above the teeth 31. The plunger 25 comprises a stem 34 which carries a cap 35 and extends through the top of the body 24. A retaining collar 36 is secured to the stem beneath the top of the body 24 and the stem terminates in a wedge—shaped member 37 directed between the jaws 29, 30. In use, water pre-heated to 35 to 40 C is introduced into the central compartment 15 through hole 17. The tank 13 is filled to the bottom of the V-shaped top with developer, also at 35 to 40 C, and tank 14 is similarly filled with a fix solution. The heater and thermostat unit 13 is then connected to a suitable power source and the temperature of the chemicals is checked at 15 minute intervals until they stabilise at the required temperature * In practice the central compartment 15 operates some 5 C higher than the outer tanks. There is a continuous lateral heat flow from the central compartment, through the tanks to atmosphere so that the chemicals quickly attain the required temperature both on initial filling and on topping-up> and once that temperature is achieved there is minimal temperature fluctuation ωithin the tanks. The clip is attached to an exposed print by grasping the clip in one hand with the fingers below one of the shoulders 27, 28, and the thumb below the other. Light pressure is then applied to the button 35 using the root of the forefinger so that the wedge-shaped member 37 is urged between the jaws 29, 30 forcing them apart. The print is then slid between the jaws ωith its back against surface 32 until it reaches stop 33 whereupon the pressure on button 35 is released allowing the jaws to close. The teeth 31 bite into the print but since it is rigidly supported by surface 32 there is minimal damage to the print and practically no masking of the print during the development process. The apparatus is designed for ease of use in low ambient light levels or total darkness. Holding the print by the clip, the back of the print is presented to the top edge of ωall 5 (Fig. 6_a), The end ωalls 3, 4, act as stops to enable the correct lateral position of the print to be determined. The print is then drawn upωards and backωards until it is felt to drop into the U-shaped top of the tank 13 (Fig. 6b_). The print is then moved to an upright position and lowered into the tank until the clip rests in the V-shaped top (Fig. 6c_). The print can be agitated in the developer using the clip. After an appropriate time the print is slowly withdrawn towards the second tank 14 (Fig. δjj). The member 16 acts as a doctor blade to wipe developer from the rear of the print whilst the front of the print drains by surface tension. Little if any developer is held by the clip, liihen the ' print is felt to locate in the second tank 14 (Fig. 6 ) it is lowered into the fix in an upright position. The print is again agitated as necessary and then removed after the appropriate time. It has been observed that with a textured surface as described above, not only is the print prevented from adhering to the interior of the tank but the surface actually appears to repel the print. The mechanism by which this occurs is not fully understood. The apparatus is suitable for processing colour or monochrome prints and up to 30 prints per hour can be processed. The chemicals can be left in the tanks for several months without oxidising. The clip may have other uses apart from the processing of photographic prints. OMPI

Claims: CLAIflS 1. Apparatus for processing photographic prints, comprising a tank for holding processing chemicals for immersion of prints, in which the interior surface of the tank that might otherwise adhere to the prints is provided with a textured finish whereby such adhesion is prevented. 2. Apparatus according to Claim 1, in which the textured finish incorporates surface indentations ( ' 23). •3. Apparatus according to Claim 2, in which there are between 1 and 100 surface indentations per square cm. 4. Apparatus according to Claim 1, comprising a pair of slot¬ like tanks (13, 14) for holding processing chemicals for immersion of prints, the tanks being disposed on opposite sides of a common heating core (15) with which they are in thermal conducting relationship. 5. Apparatus according to Claim 4, in which the tanks (13, 14) are provided with stop members (3, 4) at opposite ends of the slots and projecting from the side of the tank remote from the heating core (15). 6. Apparatus according to Claim 4, including a member (16) capable of acting as a doctor blade and located above the heating core (15). 7. Apparatus according to Claim 4, in which the heating core comprises a compartment (15) for containing water and including a heater and thermostat (18). 8. Apparatus according to Claim 4, in which the tanks (13, 14) both have V-shaped tops. 9. Apparatus according to Claim 1, including a clip comprising * a pair -of jaws (29, 30) one of which carries biting means (31), the jaws being biassed together so that the biting means closes against a rigid support surface (32) carried by the other jaw, and means (25) for moving the jaws apart. 10. Apparatus according to Claim 9, in which the biting means (31) consists of two teeth. 11. Apparatus according to Claim 9, in which the jaw that carries the rigid support surface ( 32) is provided with a stop member (33) that defines a registered stop position for an article to be gripped by the biting means. 12. Apparatus according to Claim 9, in which the jaws (29, 30) are provided by a single member ( 24) , the inherent resilience o f which biasses them together. 13. Apparatus according to Claim 9 , in which the means for moving the j aws apart comprises a wedge-shaped member ( 37) directed between the jaωs ( 29 , 30 ) . 14. A clip comprising a pair o f j aωs ( 29 , 30 ) one o f which carries .biting means (31 ) , the jaωs being biassed together so that the biting means closes against a rigid support surface (32) carried by the other j aw, and means ( 25) for moving the j aωs apart.

Inventors: NEW HARRY GRAHAM, WHETTON ROBIN ANTHONY, NEW, HARRY, GRAHAM, WHETTON, ROBIN, ANTHONY
Applicants: NEW HARRY GRAHAM, WHETTON ROBIN ANTHONY, NEW, HARRY, GRAHAM, WHETTON, ROBIN, ANTHONY
Application year: 1984
Main classification: G03D13
IPC codes: G03D13