Abstract:
A high speed motion picture film processor has a developer tank having a positive pressure relative to an ambient air pressure outside of the tank. A gas make-up system adds nitrogen inside of the developer tank while a system of seals minimizes leakage. Two seals are used along a periphery of the developer tank; one is below a sprocket level while the other is above the sprocket level. These two barriers can utilize a liquid reservoir that is filled by operation of the processor with excess liquid returning to the developer tank and they are constructed so as to allow movement. A film entrance sealing device and a film exit sealing device, each with its own housing, are also used with the developer tank; these units use a pair of rollers and a pair of flexible barriers to separate a tank gas chamber from an air chamber which is at a lower pressure and which contains a partial pressure of nitrogen fed into the entrance sealing device. The level of developer fluid is maintained at approximately the centerline of a first roller shaft but below that of a second roller shaft. The sprocket shaft has two smaller shafts mounted in metal bearings and a center tube on which the sprockets are mounted. Oxygen sensors with throttling exhaust devices outside the developer tank sound an alarm when oxygen level is too high in the developer tank. Reservoir fluid seals may also be used on secondary tanks.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention is in the field of high speed motion picture film processors. 
       BACKGROUND OF THE INVENTION 
       [0002]    Generally, the processing, sometimes also referred to as developing, of motion picture films consists of passing an exposed film though numerous different chemical solutions. 
         [0003]    Modern film processors, sometimes referred to as film developers, consist of a set of tanks, sprockets, and rollers.  FIG. 1  shows one such tank  2 . The sprockets  1  usually located on a sprocket shaft  3 , located in the top of the tank or on top of the tank  2  pull the film  7  over a set of rollers  4  mounted on a roller shaft  5 , usually located in the bottom of the tank  2 . The sprocket shaft  3  rotates, thus rotating sprockets  1  and transporting the film. The distance between the top and bottom shaft may vary between 3 and 10 feet. The number of sprockets  1  on sprocket shaft  3  may vary from a single sprocket, for very a low speed processor, to up to twenty sprockets for a large high speed processor. On the early low speed processors, all of the sprocket shafts  3  were immersed below the solution level  8  as shown in  FIG. 1 . 
         [0004]    The design speed of these processors has been increased over the years. In 1975 the fastest processors were processing film at 300 feet per minute. In 2005 some processors are running at 1000 feet per minute. The problem with processing at high speeds is that the film tension or drag increases drastically as the speed increases. At processing speeds above 1000 feet per minute the film tension becomes excessive due to solution drag. An additional problem which occurs at high speed is the whirling, or bending, of the sprocket shaft  3  which causes severe vibrations in the processor. 
         [0005]    As a result of the tension increase at higher speeds, manufacturers began lowering the solution levels such that only a lower portion of the film was submersed in the solution as shown in  FIG. 2 . This works well for most solutions with the exception of the film developer solution. The film developer, the primary solution, is the solution which actually develops the film. All other solutions, which consist of such solutions as the fix, bleach, washes etc., are referred to as secondary solutions. Thus the secondary solutions only partially cover the film as shown in  FIG. 2 . 
         [0006]    The problem with the primary solution is that the developer will oxidize when exposed to excessive amounts oxygen. Since air contains oxygen, oxidation of the developer solution can be eliminated by replacing the air with a gas which will not oxidize the developer. 
         [0007]    One section of this patent deals with the design and method of maintaining a low oxygen concentration in the tank. A second section of this patent deals with eliminating the vibrations in the processor when it is running a high speeds 
         [0008]    Filling the developer tank  2  with a non-oxidizing gas has been tried several times and found to be unsuccessful. The reason for the failure was not the principle of the approach but rather the execution. In previous attempts to do this the developer tank  2  was not properly sealed, the oxygen concentration was not monitored, the tank  2  pressure was not monitored and the film entry and exit ports were not properly sealed. Sealing the developer tank is not a trivial problem. The wet transport beams  6  may be in excess of 20 feet long and need to be raised (for maintenance purposes) by a distance of up to 10 feet above the tank  2  and again lowered to the top of the tank  2 . 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is generally directed to a high speed motion picture film processor having a film feeder, a developer tank having a positive pressure relative to an ambient air pressure outside of the tank, multiple secondary tanks and a film takeup unit wherein film is fed by the film feeder into the developer tank and then into the plurality of secondary tanks before it enters the film takeup unit. 
         [0010]    In a separate group of aspects of the present invention, the high speed motion picture film processor also has a gas make-up system for adding a non-reactive gas (such as nitrogen) inside of the developer tank and a system of seals to minimize leakage of the non-reactive gas from inside of the developer tank outside of the developer tank. The system of seals includes a first seal along a periphery of the developer tank below a sprocket level plus a tank cover and a second seal along a second periphery of the tank cover above the sprocket level, the sprocket level being determined by a centerline of a shaft that supports a plurality of sprockets used for high speed processing of film inside of the developer tank. 
         [0011]    In another, separate group of aspects of the present invention, the first and the second seals are barriers, such as a knife-edge, with a lower end in a liquid reservoir which is filled with the developer solution by operation of the high speed motion picture film processor when the high speed motion picture film processor is in operation. Both the liquid reservoir and the barrier are constructed so as to allow movement of the barrier within the liquid reservoir without allowing the non-reactive gas to exit the developer tank when the high speed motion picture film processor is in operation. The liquid reservoirs are formed by an outer wall, a trough and an inner wall, and the height of the inner wall is less than the height of the outer wall so that when the liquid reservoir overflows any overflow will flow over the inner wall into the developer tank. A mechanism (such as an overpressure relief valve) may also be used to prevent the tank cover from being lifted up by the positive pressure inside of the developer tank. 
         [0012]    In still another, separate group of aspects of the present invention, the secondary tanks may also have a dual sealing system similar to that described for the developer tank, although the secondary tank is maintained at a slight negative pressure relative to the ambient air pressure external the secondary tank. 
         [0013]    In yet another, separate group of aspects of the present invention, the developer tank also has a film entrance sealing device and a film exit sealing device, each of which has a housing, a pair of rollers located inside the housing to deflect the path of the film within the housing and a pair of flexible barriers located in the housing. The pair of flexible barriers (which may be a pair of wiper blades or a barrier pair of rollers) are located in the path of the film between the pair of rollers so that the film passes between a gap (which may be approximately a few thousands of an inch or less) between the pair of flexible barriers when the film processor is in operation. The pair of flexible barriers separate a tank gas chamber located in the housing in communication with the developer tank from an air chamber located in another portion of the housing in communication with ambient air and the tank gas chamber contains the non-reactive gas contained in the developer tank at a pressure slightly higher than the pressure in the air chamber. The air chamber of the film entrance sealing device also contains a partial pressure of the non-reactive gas contained in the developer tank and non-reactive gas can be fed into the air chamber to maintain the partial pressure. 
         [0014]    In a further, separate group of aspects of the present invention, the developer tank has a sprocket shaft with multiple sprockets and two roller shafts which each have multiple rollers located proximate a bottom of the tank but at different levels relative to one another in the tank while the developer solution is maintained at a fluid level which is approximately located at a centerline of the first roller shaft so that the rollers of the second roller shaft are above the centerline and thus above the developer solution. 
         [0015]    In still a further, separate group of aspects of the present invention, the sprocket shaft in the developer tank has a two small shafts mounted on two sets of bearings (which may be metal bearings) inside two beams with two flexible seals for preventing gas from leaving the developer tank on two sides of the developer tank opposite each other and a tube (which may be solid, but is preferably hollow) with a larger diameter than the small shafts is affixed at each of its ends to one of the small shafts, while sprockets are mounted on the tube. Rotational and lateral movement of the sprockets on and relative to the tube can be prevented. One way to prevent rotational movement of the sprockets is to use pins inserted through the tube and held in place by opposing indents formed in the sprockets. The inside of the two beams can be slightly pressurized relative to the positive pressure of the developer tank. 
         [0016]    In yet a further, separate group of aspects of the present invention, an oxygen sensor is located outside of the developer tank for sounding an alarm whenever oxygen concentration exceeds a desired set point. A gas line feeds the non-reactive gas inside of the developer tank to a filter and then to the oxygen sensor due to the positive pressure of the non-reactive gas within the developer tank, and the gas may be exhausted through a throttling device. A secondary oxygen sensor, with its own exhaust throttling device, may also be located outside of the developer tank and the flow of gas may periodically be switched between the two oxygen sensor devices. 
         [0017]    Accordingly, it is a primary object of the present invention to provide an improved high speed motion picture film processor. 
         [0018]    This and further objects and advantages will be apparent to those skilled in the art in connection with the drawings and the detailed description of the preferred embodiment set forth below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic representation of a single rack of a developing solution tank of a prior art high speed motion picture film processor. 
           [0020]      FIG. 2  is a schematic representation of a single rack of a secondary tank of a prior art high speed motion picture film processor with a lower fluid level than of  FIG. 1 . 
           [0021]      FIG. 3  is a schematic representation of a single rack of a high speed motion picture film processor in accordance with the present invention. 
           [0022]      FIG. 3A  is a top planar view of a partial cutaway along line  3 A- 3 A of  FIG. 3 . 
           [0023]      FIG. 4  illustrates a sprocket shaft design for use in a high speed motion picture film processor in accordance with the present invention. 
           [0024]      FIG. 4A  is a cross section view of  FIG. 4 . 
           [0025]      FIG. 4B  is an end view cross section of  FIG. 4 . 
           [0026]      FIGS. 5 and 7  illustrate sealing devices for a developer tank used in a high speed motion picture film processor in accordance with the present invention. 
           [0027]      FIG. 6  is a diagrammatic view of an oxygen sensor mechanism in accordance with the present invention. 
           [0028]      FIG. 8  illustrates an especially preferred fluid level in a developer tank in accordance with the present invention. 
           [0029]      FIG. 9  illustrates a pressure relief mechanism for a tank in accordance with the present invention. 
           [0030]      FIG. 9A  is a cross section view of  FIG. 9 . 
           [0031]      FIG. 10  is a diagrammatic view of a high speed motion picture film processor in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    In accordance with the present invention, a high speed motion picture film developer is disclosed that can be represented in a simplified schematic diagram as shown in  FIG. 10 . The high speed motion picture film developer, shown generally as  100 , has a film feed  103  to developer tank  101  and then secondary tanks  102  and a film takeup  104 . 
         [0033]    The present invention will now be described in connection with several especially preferred embodiments that illustrate various aspects of the inventive concepts described herein. In the Figures and the following more detailed description, numerals indicate various features of the invention, with like numerals referring to like features throughout both the drawings and the description. Although the Figures are described in greater detail below, the following is a glossary of the elements identified in the Figures:
     1  Sprocket     2  Tank     3  Sprocket Shaft     4  Roller     5  Roller Shaft     6  Beam     7  Film     8  Solution Level     9  Tank Cover     10  Gap     11  Tank Seal Channel     12  Beam Seal Channel     13  Bearing     14  Solution     16  Knife Edge     17  Liquid     18  Inside Lip     19  Seal Roller     20  Wiper Blades     21  Wiper Blade Housing     22  Filter     23  Primary Oxygen Sensor     24  Two-way Valve     25  Secondary Sensor     26  Gas Exhaust     27  Throttling Device     28  Pressure Gauge     29  Differential Pressure Gauge     30  Air Chamber     31  Tank Gas Chamber     32  Tube     33  Retainer Ring     34  Small Shaft     35  Pin     36  Ambient Air     37  Keyway     38  Direction of Film Travel     39  Upper Roller Shaft     40  Lower Roller Shaft     41  Flexible Sheet     42  Weight     43  Clamp     44  Make-up nitrogen system     46  Upper Knife Edge     48  Outside Lip of Beam Seal Channel  12       51  Lower Liquid Reservoir     52  Upper Liquid Reservoir     100  High Speed Film Processor     101  Developer Tank     102  Secondary Tanks     103  Film Feeder     104  Film Takeup   
 
         [0086]    In accordance with an especially preferred embodiment of the present invention shown in  FIG. 3 , to ensure that developer tank  101  containing developer solution  14  does not have any, or very little, oxygen, the entire tank is pressurized with a tank gas which does not oxidize the developer solution. One such gas is nitrogen. There are many other gasses which will prevent oxidation; from here on nitrogen is used as an especially preferred example in view of its ease of use and cost advantage over other gasses. 
         [0087]    To ensure that no oxygen enters developer tank  101 , the nitrogen is under positive pressure relative to the air outside the tank. To maintain the positive pressure and compensate for gas leakage, a small amount of nitrogen is continuously pumped into the tank by a make-up nitrogen system  44 . To maintain this pressure, the system has to be sealed. In an especially preferred embodiment of the present invention, gaps  10  between beams  6  and developer tank  101  are sealed by a u-shaped tank seal channel  11  (having an outer wall, a trough and an inner wall) that is welded to the entire periphery of the tank as shown in  FIG. 3 . A barrier, which may be a knife edge  16 , is attached to beams  6  as shown is  FIG. 3 . This knife edge extends into the tank seal channel  11  around the entire periphery of the tank. When tank seal channel  11  is filled with a liquid  17  to form lower liquid reservoir  51 , gaps  10  between beams  6  and developer tank  101  are sealed. (A knife edge barrier is especially preferred because there is movement in high speed film processor  100  in use so a more solid seal will not work as effectively, especially over time.) 
         [0088]    Similarly, a tank cover  9  with a similar barrier or knife edge  46  is placed into beam seal channel  12 . Beam seal channel  12  is connected to beams  6  and runs around the entire periphery of tank cover  9 . Beam seal channel  12  can be constructed with a u-shaped channel that is itself affixed to beams  6  or an outside lip  48  of the u-shaped channel can be formed by using the beam itself as a wall. Filling beam seal channel  12  with a liquid forms upper liquid reservoir  52  that provides a seal for the top of developer tank  101  in the same fashion as lower liquid reservoir  51  provides a seal for the developer tank  101  below sprockets  1 . 
         [0089]    Small shaft  34  is mounted on bearings  13 . Bearings  13  have a flexible seal on both sides of bearing  13  which seals the bearing and thus seals the inside of developer tank  101  from ambient air  36 . 
         [0090]    Since the entire developer tank  101  is under positive pressure, tank cover  9  must be of sufficient weight or must be mechanically latched to beams  6  so that tank cover  9  is not lifted up by the pressure in developer tank  101 . 
         [0091]    The seals as described above serve an additional purpose. As film  7  moves through the developer solution, a substantial amount of solution is carried to the top of developer tank  101 . The seals and covers as described above form a substantially complete seal, if not a complete seal, which prevents the solution from spilling outside developer tank  101 . 
         [0092]    As film  7  is transported through developer tank  101 , there is a tremendous amount of splashing of solution  14  throughout the tank. Inside lip  18  (i.e., the vertical section of tank seal channels  11 ) must be lower than the top edge of developer tank  101  to prevent liquid  14  from leaving developer tank  101  by spilling over the outside side of the tank. For the same reason, inside lip  18  of beam seal channel  12  (i.e., the vertical section of beam seal channel  12 ) must be lower than the top of beams  6  to prevent spilling outside of the tank since the tremendous amount of solution splashing within the tank enclosure will automatically fill seal channels  11  and  12  with developer fluid  14 . 
         [0093]    An important aspect of this especially preferred embodiment of design of tank seal channel  11  and beam seal channel  12  is that the both channels remain full of solution, due to the solution  14  splashing, at all times and thus sealing the tank  2 . 
         [0094]    The seals described above may also be employed on secondary tanks  102  having secondary solutions to prevent such solutions from spilling outside secondary tanks  102  and to also prevent undesired fumes from escaping from such tanks. Sealing the undesired fumes and preventing them from escaping into the immediate environment is extremely important. There are very pungent and environmentally damaging fumes in the tanks which do present health hazards. Secondary solution tanks  102  are usually provided with a slight negative pressure relative to the ambient pressure to ensure that any leakage into the secondary tanks will be exhausted to the outside of the processor building. 
         [0095]    In addition to all of the seals mentioned above, developer tank  101  needs a sealing device which seals film  7  as it enters and exits developer tank  101 .  FIG. 5  shows such a sealing device which seals film  7  as it exits developer tank  101 . The direction of film travel  38  is shown in  FIG. 5 . Film  7  passes over two seal rollers  19 . Each of these rollers  19  deflect the film path by a slight amount as the film bends around the rollers such that film  7  is not free to flutter between the rollers. Between rollers  19  there are two flexible barriers. In an especially preferred embodiment, the flexible barriers are wiper blades  20 , although the barriers might also be another set of rollers or some other barrier device that will not damage the film but still serve to create two chambers. Wiper blades  20  may be adjusted such that they just touch film  7  or such that there is a small gap between film  7  and the wiper blade  20  (which can be made of a suitable flexible material such as rubber or plastic). Wiper blades  20  and rollers  19  are enclosed by a housing  21 . The width of wiper blades  20  is only a few thousands of and inch wider than the width of film  7 . The width of the cavity in the wiper blade housing is slightly wider (which can be a few thousands of an inch) than the wiper blade. This ensures that only a small amount of gas escapes into the environment. Housing  21  is mounted either on top of the tank cover  9  or through a wall separating developer tank  101  from the adjoining tanks. The lower portion of housing  21 , which is connected to the tank cover, is automatically filled with nitrogen from developer tank  101 , and this is called tank gas chamber  31 . The wiper blades separate tank gas chamber  31  from air chamber  30 . A small amount of nitrogen will escape to ambient air  36  as the film exits the tank through tank gas chamber  31  and air chamber  30 . This nitrogen has to be replenished by an outside source. 
         [0096]    As liquids are added or removed from developer tank  101  the tank pressure may change. If the tank pressure becomes negative the tank will suck in air and therefore oxygen. Consequently, the nitrogen pressure must be controlled with a pressure regulator and must at all times be positive relative to the pressure external to developer tank  101 . This positive pressure assures that there is a positive pressure gradient moving from tank gas chamber  31  to air chamber  30 . Also, when high speed film processor  100  is turned off, the gas temperature of gas inside of developer tank  101  will cool (the solution might be at 100° F. when running) and additional nitrogen must then be added to the inside of developer tank  101  to maintain its positive pressure (according to Boyle&#39;s Law). 
         [0097]    The film seal device for sealing the film as it enters developer tank  102  is shown in  FIG. 7 . This is quite similar to the device shown in  FIG. 5  with the following difference. 
         [0000]    As a result of nitrogen passing from tank gas chamber  31  to air chamber  30  there is a certain tank gas concentration in air chamber  30 . This is important for the film entering developer tank  101 . A partial tank gas atmosphere in air chamber  30  ensures that the perforations in the film are at least partially purged of oxygen. This causes less oxygen to be drawn into developer tank  101 . Also, air chamber  30  can be designed to be very large and the partial pressure of tank gas inside of air chamber  30  can be controlled through addition of tank gas into air chamber  30  to minimize oxygen that might be carried into tank gas chamber  31  by film perforations. 
         [0098]    Running processors at high speeds requires that sprocket shaft  3  is quite straight.  FIG. 4  shows an especially preferred sprocket shaft design in accordance with the present invention which is capable of carrying a high load while still remaining quite straight. The shaft consists of a tube  32  which is at least 2 inches in diameter and is much more rigid than a traditional sprocket shaft  3 . It is especially preferred that tube  32  be at least partially hollow due to weight and cost concerns, although a solid shaft would still be an improvement over prior devices because of its increased stiffness. Sprockets  1  (only two sprockets are shown in  FIG. 4 ) are held on the shaft by a retainer ring  33 , or a circular clamp, at each end of the shaft. Screwed or welded into each end of the shaft is a solid smaller shaft  34  with a diameter small enough to fit into a metal bearing  13 . The individual sprockets  1  are kept from rotating on the shaft by pins  35  as shown in  FIG. 4 . Pins  35  are longer than the diameter of the shaft and protrude from each side of the shaft. Sprockets  1  have two keyways  37  on the inside bore which are spaced 180 degrees apart. It is these keyways  37  which keep pins  35  from falling out of tube  32 . 
         [0099]    In an especially preferred embodiment of the present invention small shafts  34  are not submersed. Submersed shafts can ordinarily only be run on plastic bearings because of corrosion problems encountered in the liquids. When small shafts  34  are mounted on the surface, they can be mounted on metal bearings which have a far longer life than plastic bearings. In order to prevent the developer solutions from migrating into the bearings, the inside of beams  6  are slightly pressurized relative to the inside of developer tank  101 . This pressure causes any fluid which might migrate into the bearing to be forced out of the bearing and back into developer tank  101 . 
         [0100]    In order to ensure that developer tank  101  is always pressurized the tank must be equipped with a pressure gauge and an alarm which will sound if the pressure in the tank falls below a minimum set point. 
         [0101]    Additionally, it is especially preferred that developer tank  101  is equipped with a primary oxygen sensor  23  ( FIG. 6 ) which will indicate the oxygen level and sound an alarm whenever the oxygen level exceeds a desired set point. Because the sensing element of primary oxygen sensor  23  may become damaged in time from pollutants from the developer solution, a filter  22 , such as an activated charcoal filter, should be placed in line between the tank and the oxygen sensor as shown in  FIG. 6 . To ensure that oxygen sensor  23  is operational, it is especially preferred that a secondary oxygen sensor  25  be installed in the system and gas flow from the tank may be switched periodically by a two-way valve  24  to determine if primary oxygen sensor  23  is operating properly. The pressure for the gas flow through the oxygen sensor is provided automatically by the pressure inside developer tank  101 . The gas leaving sensors  23  and  25  is exhausted to the ambient air through gas exhaust  26 . To ensure that the concentration of gas inside the oxygen sensors  23 ,  24  reflects the gas concentration inside developer tank  101 , a throttling device  27  is placed at the exhaust end of gas exhaust  26 . Throttling device  27  may consist of a small orifice or a porous material. An additional purpose of throttling device  27  is to limit the amount of gas escaping the system. To ensure that the tank  101  pressure is positive, a pressure gauge  28  is connected to the tank  101 . See  FIG. 6 . To ensure that filter  22  is not clogged, a pressure gauge  29  is connected between the input and the output of filter  22 . Pressure gauge  28  must have an alarm which rings when the pressure in the tank falls below a certain set point and an alarm set point which rings when the pressure exceeds a predetermined point. 
         [0102]      FIG. 3  shows a single roller shaft  5  at the bottom of tank  2 . In practice and for practical reasons there are often two roller shafts, upper roller shaft  39  and lower roller shaft  40 , as shown in  FIG. 8 .  FIG. 3  shows the solution level  8  covering all rollers  4 . As shown in  FIG. 8 , when the rollers  4  are divided between upper roller shaft  39  and lower roller shaft  40 , it is possible to have the solution level  8  cover only the lower rollers  4 . Covering only half the rollers with a solution cuts the film drag in half. This in turn reduces the horsepower required to run the entire processor. Additionally, for purposes of reducing the film drag, it is especially preferred that solution level  8  be lowered to the centerline of lower shaft  40 . 
         [0103]    Upon starting the processor  100 , referring to  FIG. 8 , the gas above the solution level  8  is typically at a lower temperature than the solution at the bottom of the tank. Once the solution is mixed with the gas covering the solution, the gas in developer tank  101  rapidly increases in temperature. This increase in temperature will cause an increase in gas pressure. To prevent this pressure from forcing the liquid  17  out of seal  12  developer tank  101  has to be equipped with a pressure relief valve. One design of such a valve is shown in  FIG. 9 . This particular pressure relief valve may be placed on top of a small hole of the tank cover  9 . This particular relief valve consists of a flexible sheet  41 . This flexible sheet may consist of either a rubber-like or plastic material. Attached to the top of the flexible sheet  41  is a weight  42 . This weight  42  must be of sufficient weight to maintain the gas pressure within developer tank  101  but light enough to prevent liquid  17  from being forced out of seal  12 . Flexible sheet  41  may be attached to the tank cover by a clamp  43  as shown in  FIG. 9 . It is especially preferred that an overpressure relief valve is used in both developer tank  101  and in secondary tanks  102 . 
         [0104]    While the invention has been described herein with reference to several especially preferred embodiments, these embodiments have been presented by way of example only, and not to limit the scope of the invention. Additional embodiments thereof will be obvious to those skilled in the art having the benefit of this detailed description, especially to meet specific requirements or conditions. For example, while the preferred embodiments have been disclosed as using a liquid reservoir system for seals along the periphery of the developer or secondary tanks, a different suitable seal system could also be put into place, such as an inflatable seal that could replace the liquid reservoir system and still accommodate movement which is common when the high speed motion picture film processor is in operation. Further modifications are also possible in alternative embodiments without departing from the inventive concept. 
         [0105]    Accordingly, it will be apparent to those skilled in the art that still further changes and modifications in the actual concepts described herein can readily be made without departing from the spirit and scope of the disclosed inventions as defined by the following claims.