Abstract:
Processing solution is delivered to a processing apparatus by means of a syringe type delivery system.. The container in which the solution is stored acts both as the storage container and as part of the metering system for delivering an accurate volume of solution.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to the photo-processing industry. In particular it relates to the delivery of processing solutions to a processor.  
         BACKGROUND OF THE INVENTION  
         [0002]    Containers in the form of cartridges are used to supply ready to use processing solutions to photographic processing apparatus. These containers are designed to be easily and quickly coupled to the apparatus. With respect to both kiosk and highly dispersed processing it is of interest to be able to supply the customer with easily replaceable chemical concentrate cartridges that are apparently dry, i.e. there is no contact with the solution itself It is also desirable to be able to deliver the concentrates accurately from the said cartridges into the processing apparatus. This invention combines these two criteria to provide a method that achieves both requirements in a robust cost-effective way.  
           [0003]    Commonly mastics and sealant are available from DIY stores packaged in a large syringe type canister. Normally the syringe end is cut and the piston depressed with a “gun” to squeeze the sealant from the syringe. The contents of the syringe are normally of high viscosity, being paste or gel or Acrylic based. For example, Alpha Metals, a manufacturer, packs “Fernox”™, a central heating corrosion inhibitor gel into similar containers. They use a metal foil to seal the plunger end. As the packaging is made from high-density polyethylene and the plunger from low-density polyethylene the cartridge is easily recycled when empty.  
           [0004]    It is an aim of the invention to provide a low cost accurate method of delivering processing chemistry to the customer and into the machine. It is an aim to provide a syringe delivery system for low viscosity fluids in which there is substantially no leakage and in which the containers for the processing solutions are recyclable. It has been have found by experimentation that the same container as described above can hold a low viscosity liquid without spillage even when the plunger is activated. This is due to the integrity of the seal and the hydrophobicity of the plastic material.  
         SUMMARY OF THE INVENTION  
         [0005]    According to the present invention there is provided a method of delivering processing solution to a processing apparatus wherein the solution is supplied in a storage container, the container forming part of a metering system.  
           [0006]    The invention further provides a delivery unit for supplying processing solution to a processing apparatus, the unit comprising a storage container having a nozzle at one end thereof and incorporating a piston therein, and means for activating the piston such that a fixed amount of solution is delivered out of the container via the nozzle each time the piston is activated.  
           [0007]    It has been found that solution can be delivered with remarkable accuracy by means of a simple, low cost yet effective mechanism described below.  
           [0008]    Preferably a plastic seal is provided behind the piston.  
           [0009]    The invention provides for the solutions used in a photoprocessing apparatus to be housed in an air tight, leak proof, robust, “apparently dry” container. This container is also part of the delivery mechanism. As the container is air-tight there is no solution movement within the container. This is particularly advantageous since the container therefore acts as a solid component during transport, installation and operation. It is not flexible and therefore does not require any external packaging for protection.  
           [0010]    The invention avoids the need to supply the processing chemistry in separate containers which then require use of accurate pumping equipment for delivery.  
           [0011]    The mechanism of the piston allows highly accurate delivery of the solutions at low cost.  
           [0012]    The container size and fill volume can be easily adjusted to suit the solution to be housed. The volumes may be such that all containers empty at one time or at different times.  
           [0013]    The containers are fully recyclable.  
           [0014]    The invention may be used in all processes and at all process stages.  
           [0015]    Use of a separate plastic seal ensures a “dry” system.  
           [0016]    It would be advantageous to use a plastic seal (as is used over Kodak™ SM™ chemical packaging couplings) to ensure no chemical leak and to aid recycling of the container.  
           [0017]    A conventional inexpensive “off the shelf” dispensing gun can be used to provide the dispensing apparatus.  
           [0018]    The invention is particularly useful for single part chemistry, e.g. Kodak Ektacolor Prime SP™. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    The invention will now be described, by way of example, with reference to the accompanying drawings, in which:  
         [0020]    [0020]FIG. 1 is a schematic side view of a container suitable for use with the invention;  
         [0021]    [0021]FIGS. 2 and 3 are schematic views of such a container with alternative ends to the nozzle;  
         [0022]    [0022]FIG. 4 is a schematic side view of a delivery unit in accordance with the invention;  
         [0023]    [0023]FIG. 5 shows the same unit once it has been emptied;  
         [0024]    [0024]FIG. 6 is a schematic view showing the operation cycle of the cam;  
         [0025]    [0025]FIGS. 7A and 7B illustrate two methods of changing the stroke of the piston within the container;  
         [0026]    [0026]FIG. 8 illustrates a further container suitable for use with the invention;  
         [0027]    [0027]FIG. 9 illustrates a method of activating the piston within the container; and  
         [0028]    [0028]FIG. 10 illustrates a further method of activating the piston within the container. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]    [0029]FIG. 1 shows the general arrangement of the photographic chemical delivery and supply container.  
         [0030]    A cylinder  2  houses the photographic solution  1 . The cylinder  2  has a nozzle  4  at one end. This nozzle is sealed with a break off tip  3  at the end thereof. The cylinder  2  is also provided with a movable piston  6 . The front end of the piston has a protrusion or shaped member sized to fit into the nozzle  4  of the cylinder  2 . A removable or pierceable seal  5  is provided behind the piston  6 . The seal  5  is provided in case some photographic solution seeps past the piston  6  during storage before use.  
         [0031]    In storage the container is full of photographic solution  1  and the piston  6  is at the opposite end of the cylinder from the nozzle  4 . When the solution is required to be delivered to the processing apparatus the piston  6  is operated to push the solution out of the nozzle  4 . FIGS. 2 and 3 illustrate two alternative ends for the nozzle  4 . It will be understood by those skilled in the art that the invention is not limited to the two embodiments illustrated.  
         [0032]    [0032]FIG. 2 shows a non-return valve  7  fitted to the end of the nozzle  4 . This valve  7  will lift to pass solution only when the piston  6  raises the pressure in the cylinder  2  during a solution delivery cycle.  
         [0033]    [0033]FIG. 3 shows a plug  8  fitted into the end of the nozzle  4 .  
         [0034]    In the operation of the embodiment shown in FIG. 3 the cylinder  2  full of solution  1  is pushed into the opening  50  of the processing apparatus. This opening includes a conical rubber seal  9  which seals against the nozzle  4  with the aid of a moulded feature  10 . A hollow probe  12  then pierces the plug  8  and enters the cylinder  2  where the solution is held. The piston  6  then pushes out the solution through the probe  12 .  
         [0035]    [0035]FIG. 4 shows the cylinder  2  fixed firmly within a cam operated delivery unit  13 . The delivery unit has two chambers, one housing the cylinder  2  and the second housing activation means for the piston  6 . The chambers are connected via a bore to allow passage of a push rod plunger  15 . A front stop plate  14  is located at the front of the delivery unit  13 . The front of the cylinder  2  is pushed up to the front stop plate  14  by means of the push rod plunger  15 . The nozzle passes through a corresponding opening in the front wall of the first chamber. A cam-plate  16 , located external to the delivery unit  13 , has an operating pin  17  attached thereon. The operating pin  17  bears against one end of a lever  19 . The other end of the lever  19  bears against a one way clutch plate  20 . The clutch plate  20  is movably located on the push rod plunger  15  and is biased by spring  21 . The spring is retained between the clutch plate  20  and the front wall of the second chamber.  
         [0036]    In use, as the cam-plate  16  rotates the operating pin  17  moves with it. The movement of the pin  17  pushes the operating lever  19  back and forth in the direction of the arrow shown in FIG. 4. The lever  19  bears against the clutch plate  20  causing it to tip and grip the push-rod plunger  15 . This causes the plunger  15  to advance. As it advances it pushes piston  6  forward and delivers a shot of solution. The cam-plate  16  and pin  17  continue to rotate, releasing the clutch plate  20  from the push-rod where upon spring  21  pushes it back to its starting position.  
         [0037]    Since the cam  16  moves a predetermined distance and this in turn moves the piston  6  a fixed amount of solution is delivered at each stroke. The cam is operated by an electric motor, not shown.  
         [0038]    [0038]FIG. 5 illustrates how the shape of the piston  6  ensures that all of the solution  1  is delivered.  
         [0039]    The front end of the piston  6  has a shaped member or protrusion  22 . As explained above, the protrusion  22  is designed to fit exactly into the delivery nozzle  4  so that when the piston has swept the full length of the cylinder  2  the shaped protrusion has also displaced any solution that might remain in the nozzle.  
         [0040]    [0040]FIG. 6 illustrates the motion of the cam-plate pin  17  and lever  19  as it completes one cycle.  
         [0041]    The amount of solution dispensed from the cylinder can be very accurately varied and controlled by simply changing the stroke of the clutch and hence the displacement by the piston. FIG. 7 shows two method of doing this. FIG. 7A illustrates how the stroke is changed by moving the position of the pin  17  on the cam-plate  16 . FIG. 7B illustrates how the stroke is changed by moving the whole cam-plate assembly back or forth, as indicated by the arrow, with respect to the lever  19 .  
         [0042]    As the piston only advances one way no air gets into the container. There is therefore no solution movement within the container once it is packed. It therefore acts as a “solid” component, having the aforementioned advantages.  
         [0043]    Another method of actuating the piston would be to use a screw thread mechanism. This is illustrated in FIG. 9. A screwthread  30  is attached to the rear of the movable piston  6 . The screwthread  30  passes through a threaded central hole in gear  31 . Gear  31  is in drive connection with the gear  32 . Gear  32  is connected via drive shaft  35  to motor  33 . The cylinder  2  is supported by support member  34 .  
         [0044]    When solution is to be dispensed from the cylinder  2  the motor  33  is activated. The motor  33  drives gear  32  which in turn drives gear  31 . As the gear  31  has a threaded central hole the screwthread  30  is moved linearly by the movement of the gear  31 . The screwthread is not rotated by movement of the gear  31 . As the screwthread moves linearly it pushes the piston  6  towards the nozzle of the cylinder, thus dispensing the solution. This mechanism can be continuously variable by altering the number of rotations of the threaded screw. Accurate and variable control of solution delivery is hence obtained.  
         [0045]    A further method of actuating the piston is illustrated in FIG. 10. In this embodiment a magnet  40  is provided on the piston  6 . A pneumatic or hydraulic cylinder  42  is in connection with the rear of the piston  6  via a push rod  45 . The cylinder  42  is provided with control means  43 . An electromagnetic sensing coil  41  is located adjacent the cylinder  2 . Sensing means  44  is in electrical connection with the coil  41 .  
         [0046]    When solution is to be dispensed from the cylinder  2  the pneumatic or hydraulic cylinder  42  is activated. The piston  6  moves forward, pushing solution out of the nozzle. As the piston moves magnet  40  moves with it. The movement of the magnet  40  cause a change in the electromagnetic field of the sensing coil  41 . This change is detected by the sensing means  44 . When the piston has moved a predetermined distance, and thus dispensed a predetermined volume of solution, a signal is sent from the sensing means  44  to the control means  43  causing the cylinder to stop moving the piston rod  45 .  
         [0047]    Although a pneumatic/hydraulic cylinder has been illustrated it will be understood that any linear drive mechanism could be used.  
         [0048]    In both FIGS. 9 and 10 the piston  6  is shown without the nozzle shaped front for simplicity.  
         [0049]    The above are examples of actuating the piston. It will be understood that any suitable method may be used.  
         [0050]    In all of the examples described above the sealing membrane  5  has been removed prior to use. In the embodiment shown in FIG. 8 this membrane  5  can be left in place as the push rod is provided with a spiked cutter  24 . The spiked cutter opens a hole in the membrane, pierces the piston and punctures the outlet end of the cylinder before the plunger engages with the piston.  
       EXAMPLE  
       [0051]    In Run  1  a 1 liter cylinder supplied by Fisbach, a manufacturer, was fitted to a delivery gun supplied by Kennet, a manufacturer, which was actuated via a cam to deliver a set movement of the gun&#39;s trigger. After each rotation of the cam the mass of water delivered from the cylinder into a container on a balance was measured. After a predetermined number of strokes the mean volume (ml) delivered, the standard deviation, the maximum and the minimum volumes (ml) were calculated. The experiment was repeated in Run  2  with a reduced trigger movement. The data below show the results obtained were quite accurate considering the low cost and complexity of the delivery gun.  
                                             Run 1                                     1   16.27            2   16.16            3   16.28            4   16.37            5   16.43            6   16.45            7   16.42            8   16.29            9   16.21           10   16.22           11   16.24           12   16.2            13   16.22           14   16.18           15   16.12           16   16.19           17   16.27           18   16.14                      
 
         [0052]    [0052]                                                       Mean   16.26           Standard deviation   0.099           Max   16.45           Min   16.12                        
         [0053]    [0053]                                             Run 2                                     1   5.501            2   5.466            3   5.513            4   5.492            5   5.48             6   5.514            7   5.414            8   5.561            9   5.49            10   5.51            11   5.585           12   5.509           13   5.496           14   5.546           15   5.5            16   5.47            17   5.61            18   5.5            19   5.6            20   5.52            21   5.48            22   5.51            23   5.46            24   5.46            25   5.56                         
         [0054]    [0054]                                                       Mean   5.509           Standard deviation   0.046           Max   5.61           Min   5.414                        
         [0055]    The interface between the processing equipment and the syringe could either be via moulded threaded part that mates with a corresponding fitting on the machine or by a system that punctures the moulded seal as the unit is screwed into a housing.  
         [0056]    It is possible that the syringes that contain different photochemicals have different pin registrations, to ensure that the wrong solution is not fitted to the chemical delivery system. This would be deleterious to the process. Other means of ensuring that the correct solutions are supplied to the system is to have different threads or other moulded parts of the containers for different solutions. It is apparent that any photographically useful chemical could be packed in this way and syringes of various volumes are available. Air is excluded from the packaging and photochemicals should display good storage. The delivery unit is apparently dry. As no air is included it will not feel like solution is contained within.  
         [0057]    The invention has been described in detail with reference to preferred embodiments thereof. It will be understood by those skilled in the art that variations and modifications can be effected within the scope of the invention.