Patent Publication Number: US-8122819-B2

Title: Machine for injecting liquids

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority benefit from application Ser. No. 10/361,459, filed on Feb. 10, 2003 (now U.S. Pat. No. 6,976,421), which is a continuation-in-part of application Ser. No. 09/899,492, filed on Jul. 3, 2001 (now U.S. Pat. No. 6,763,760), each of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a machine for injecting liquids into materials having the consistency of foodstuffs. 
     2. Description of the Related Art 
     U.S. Pat. No. 5,053,237 of Deloy G. Hendricks and Conly L. Hansen provides an apparatus for the needleless injection of injectate into meat. 
     According to lines 33 through 40 in column 4 of that patent, “[A] nozzle injection apparatus causes the injectate to travel from a reservoir under pressure through a valve and out of a nozzle. Sufficient pressure must be provided such that the injectate can travel completely through the cut of meat, if desired. At the same time, temperature controls must be provided so that the injectate leaves the nozzle at a temperature within a desired temperature range.” 
     Lines 41 through 48 of column 6 and lines 3 through 26 of column 7 consistently explain: 
     “ . . . The injection apparatus 10 will, in most cases, include a temperature control feature, such as a water bath 12, for controlling the temperature of the fluid to be injected (“injectate”). The actual injectate fluid will be contained within reservoir 14 disposed within the confines of water bath 12. It is crucial that the temperature be controlled within certain ranges in order to provide for proper injection. 
     “The apparatus of the present invention also includes a pump 16 and an adjustable relief valve 18 or pressure control assembly. Thus, the injectate can be pumped in a controlled manner from the reservoir through a nozzle assembly 20. 
     “Also useful in the present apparatus is an electric solenoid valve 22, which may be placed in communication with an adjustable timer to control duration of the bursts of injectate. Thus, the volume of injectate can be carefully controlled as can the amount of injectate which leaves the system. This apparatus can then be connected to a starter and relay to operate the valve 22. 
     “The injection apparatus will include a nozzle assembly 20. The nozzle assembly will function to direct the injectate in the proper direction and to maintain the stream of injectate at the proper volume. The nozzle assembly 20 may include a plurality of individual nozzles 24. 
     “The various components of the apparatus are placed in fluid communication by lines including recycle line 26, a feed line 28, and reservoir line 30. 
     “Finally, the apparatus illustrated in FIG. 9 includes an injection table 32 to provide support for the meat being injected.” 
     U.S. Pat. No. 6,165,528 of Yoshihiko Tanaka et al. discloses another apparatus for the needleless injection of injectate into meat, which it terms a “pickle injector.” This patent asserts, on line 66 of column 9 through line 8 of column 10: 
     “The pickle injector of the invention is a device for injecting the liquid substance into the green meat. The pickle injector is provided with a high-pressure liquid generator, a liquid-substance injecting section, and a pressure controller which can control the injection pressure while injecting the liquid substance when the liquid substance is injected from the injecting section to the green meat.” 
     “The high-pressure liquid generator in the pickle injector the invention may be any mechanism, as long as it can increase the pressure of the liquid substance to a high level . . . ” 
     No recognition is given in U.S. Pat. No. 6,165,528 is given to the fact that the injectate will be heated by passing through the pump and the pressure controller; nor is there any discussion concerning reclaiming injectate that does not find its way into the meat. 
     The apparatus of U.S. Pat. No. 6,165,528 does, however, preferably employ a manifold, as described in line 33 through 60 of column 10: 
     “ . . . the high-pressure liquid substance is transferred from the high-pressure liquid generator via the high-pressure piping to the injecting section, and it is preferable to use the injecting section which has a member called a manifold for branching a single flow from the high-pressure piping to plural flows. The manifold is preferably placed on the tip end of the injecting section, but can be placed midway in the piping as the case may be. 
     “The injecting section of the conventional high-pressure liquid generator is of a single-hole type or has a form in which the piping in the manifold is branched radially. The present inventors have manufactured a manifold especially suitable for a pickle injector for meat, piping in the manifold is branched and the branched pipes are parallelly arranged. Here, the parallel arrangement includes not only the arrangement where the pipes are arranged parallel in a row but also the arrangement where the pipes are arranged zigzag or parallel in multiple rows. By arranging nozzles parallel, a nozzle interval can be narrowed to 10 mm or less, e.g., 5.6 mm for injection. Therefore, a highly dense and uniform injection is feasible. Further preferably used is a manifold which has multiple coherent stream injection nozzles arranged parallel in this manner. 
     “When the manifold is used, the high-pressure liquid substance is injected as the coherent stream from the nozzle on the tip end of each piping. The liquid substance is injected simultaneously from the parallel arranged nozzles to the green meat . . . . ” 
     Subsequently, U.S. Pat. No. 6,165,528 explains, in lines 44 through 47 of column 17, “The liquid substance is injected as a coherent stream from the tip end of the injection nozzle of the manifold 7 in contact with the green meat.” Thus, the nozzle actually touches the meat, creating an increased risk of contamination. 
     In lines 42 through 45 of column 18, similar language describes another embodiment. Also for this other embodiment, however, lines 34 through line 36 of column 18 indicate, “The manifold 7 is . . . lowered from above to hit against the green meat.” 
     Although in lines 10 through 11 of column 17 and in line 16 of column 18, U.S. Pat. No. 6,165,528 states that high-pressure piping 6 is “constituted of a flexible hose,” no purpose is given for this flexibility. Thus, it is logical to assume that the flexibility is for the traditional purpose in high-pressure lines, viz., absorbing forces associated with the pressure that could damage a more rigid line. 
     Finally, in its Description of the Related Art, U.S. Pat. No. 6,165,528 provides a summary of needleless injectors and related devices. 
     To the best of the inventors&#39; knowledge, all previous needleless injectors have utilized pumps, such as positive displacement pumps, which must run continuously in order to maintain the fluid to be used as an injectate under constant high pressure. Heat generated by such continuous operation is transferred to the injectate as it passes through the pump. 
     Moreover, in the practical implementation of U.S. Pat. No. 5,053,237, once the pressure in the system reached the desired level, a pressure relief valve 18 would prevent the continuously running pump 16 from further raising the pressure. This was accomplished by allowing the injectate to flow from the pump 16, through the pressure relief valve 18, and back to the reservoir 14 that supplied the pump 16 with injectate. A solenoid valve 22 allowed the injectate to flow to the nozzles 24 of the nozzle assembly 20 when desired. The re-circulation of the injectate through the continuously running pump 16 tended to raise the temperature of the injectate even more. 
     Not only is a cooling system necessary to keep the injectate within the required temperature range, but the added volume in plumbing necessary to provide the recycling and the additional capacity within the reservoir 14 to account for the injectate that is being cooled within the water bath 12 requires a greater quantity of injectate than would otherwise be necessary. This, in turn, mandated the use of a larger pump 16. More energy was required both because of the larger capacity of the pump 16 and because of the continuous operation. And since injectate is purged when it is desired to use another fluid as the injectate, the cost of injectate was higher. 
     Further, there is an interest in a needleless injection apparatus that can inject a liquid into a subject with minimal damage to the subject itself. There is also an interest in a needleless injection apparatus that can be easily maintained and cleaned in accordance with applicable governmental food safety standards. In addition, there is a need for a needleless injection apparatus that is capable of operation within an existing continuous food preparation/production manufacturing facility without a significant investment in additional equipment and without significant modification of an existing manufacturing process. 
     Accordingly, reducing exposure of machine components to moisture in the production environment is required to minimize maintenance of the machine. Further, minimizing exposure of the threading on key machine components to the injection fluid or a cleaning solution is required to enhance longevity of the machine and to reduce possible contamination of the injection subjects. 
     In addition, operation in a continuous environment requires immediate reaction to subtle changes in production process variables. For example, an injection spray that is substantially uniform, without any hesitation during or between injection bursts is required. Accordingly, a method to ensure steady and consistent injection bursts is needed. In addition, the ability to automatically refresh the fluid supply is also desirable. 
     SUMMARY OF THE INVENTION 
     The present inventors recognized the preceding disadvantages of the systems in the prior art and developed a needleless injection apparatus that utilizes one or more commercially available air booster pumps. Such a pump generates less heat by operating only when necessary to maintain a desired pressure. 
     The Machine also employs a head which preferably, but not necessarily, has injectate introduced into the head through apertures in the walls of a hollow tube inside the head that is in fluid communication with the air booster pump. The head has apertures for one or more nozzles. The apertures are preferably, but not necessarily, preferably, but not necessarily, designed so that an input end of the nozzle lies within the head at a point with enough distance to the interior of the wall of the head that any particles within the injectate will tend to fall to a level below the input end of the nozzle and not enter and thereby clog the nozzle. 
     The head is preferably, but not necessarily, designed so that upon installation one point of the inside of the head will be at substantially the highest elevation. Near such point the head has an escape aperture so that any gas within the injectate that enters the head will tend to flow to and through such escape aperture. Furthermore, a return line preferably, but not necessarily, takes injectate that flows through the escape aperture to the low-pressure side of the air booster pump. And also, a drain, in a work surface to which the head is preferably, but not necessarily, mounted, preferably, but not necessarily, reclaims injectate and transports it to the low-pressure side of the air booster pump. 
     In order to improve performance of the Machine and minimize outgassing from the injectate, either the source of the injectate is pressurized or a pump is inserted between the source and the air booster pump. 
     Preferably, but not necessarily, a main injectate filter is located between the source of the injectate and the air booster pump; and, preferably, but not necessarily, the design of the Machine permits this main injectate filter can be replaced while the Machine is operating. 
     A cleaning aperture is preferably, but not necessarily, located in each end of the head. 
     A conveyor belt is preferably, but not necessarily, in a work surface to which the head or heads are, preferably, but not necessarily, mounted and has an endless belt containing so that the head or heads can be mounted either above or below the conveyor belt. The conveyor belt is preferably, but not necessarily, one which may operate at different speeds. 
     Ozone may be added by the Machine to the injectate or applied to the subject of the injection. 
     And a computer device preferably, but not necessarily, controls many of the components and functions of the Machine. 
     Further, it may be seen that an improved machine for injecting liquids includes least one injection head movably mounted to an enclosure, with each injection head having an escape aperture, a plurality of injection apertures and nozzles attached thereto. End caps are installed on to each injection head in such a manner that prevents the injection fluid from contacting any threading present in the injection head, which simplifies cleaning of the machine and reduces the possibility of injection fluid contamination. 
     In addition, stand-alone, easily removable filters are provided within the injection heads over the feed entry ports to remove particulate matter from the injection fluid and to increase the turbulence of the entering fluid. These filters also are positioned within the injection head so as to prevent the injection fluid from contacting any threading present in the injection head. 
     Further, fast acting solenoid valves are attached to the escape apertures for quickly and automatically releasing any air build-up located within the injection heads. The solenoid valves are located within the enclosure and away from the wet working production environment, thereby improving the ability to clean the machine during production downtime. 
     In addition, the air pumps are mounted within the enclosure and provide the high-pressure liquid to the injection heads. A controllable, high-pressure regulator is used to automatically adjust the output pressure of the air pumps thereby ensuring that the injection spray is substantially uniform and the air pumps function without any hesitation during or between injection bursts. 
     Further, the injection fluid coming out of the high-pressure air pumps is first directed to an injection manifold system which includes a number of high-pressure solenoid valves. The manifold system further ensures the fluid and going to each manifold head during an injection burst is substantially similar in pressure and volume. 
     It may therefore be seen that the present invention teaches both a machine for needleless injection of liquids into a subject, and a method of injecting subjects using high-pressure injection bursts that do not contact the injection subjects. Further, the machine for injecting liquids of the present invention provides for improved injection of subjects by reducing the risk of contamination of the injection subject and simplifying cleaning of the machine. Further, automatic control of the machine by an operator and easy integration into a production facility are also features of the improved machine for injecting liquids of the present invention. 
     The machine for injecting liquids of the present invention is of a construction which is both durable and long lasting, and which will require little or no repair to be provided by the user throughout its useful lifetime. The machine of the present invention is also of relatively inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the machine for injecting liquids of the present invention are achieved without incurring any substantial relative disadvantage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  represents in schematic form the Machine for Injecting Liquids in an embodiment with no reservoir and no recycling of injectate; 
         FIG. 2  represents in schematic form the Machine for Injecting Liquids in an embodiment with one reservoir but no recycling of injectate; 
         FIG. 3  represents in schematic form the Machine for Injecting Liquids in an embodiment with one reservoir and recycling of injectate; 
         FIG. 4  represents in schematic form the Machine for Injecting Liquids in an embodiment with two reservoirs and recycling of injectate; 
         FIG. 5  represents in schematic form the Machine for Injecting Liquids in an embodiment with the capability of adding ozone to the injectate; 
         FIG. 6  shows the exterior of the Machine for Injecting Liquids in an embodiment having a drain; 
         FIG. 7  illustrates the exterior of the Machine for Injecting Liquids in an embodiment having a catch basin in conjunction with the drain; 
         FIG. 8  is an isometric view of the injection apparatus of the present invention, showing a front side thereof; 
         FIG. 9  is top plan view of the injection apparatus shown in  FIG. 8 ; 
         FIG. 10  a plan view of the injection apparatus shown in  FIGS. 8 and 9 , showing a back side of the cabinet; 
         FIG. 11  is side plan view of a portion of the injection apparatus shown in  FIGS. 8 through 10 , showing a channel and a conveyor system mounted within the channel; 
         FIG. 12  is a bottom plan view of an injection head of the injection apparatus shown in  FIG. 11  taken along line  12 - 12 ; 
         FIG. 13  is a cross-sectional view of an injection head of the needleless injection apparatus shown in  FIGS. 8 through 12 , showing a tubular filter disposed therein; 
         FIG. 14  is a vertical section of a fluid-in end cap of the injection apparatus shown in  FIGS. 8 through 13 ; 
         FIG. 15  is a partial cross-sectional view of an injection head of the injection apparatus shown in  FIGS. 8 through 13 , showing a disk filter disposed therein; and 
         FIG. 16  is a plan view of the injection apparatus shown in  FIG. 8 , showing a back side thereof with doors removed. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1 through 8  illustrate several embodiments of a needleless injection systems constructed in accordance with the present invention. Accordingly, the present invention is a needleless injection apparatus  30  that utilizes one or more commercially available air booster pumps  32  which employs relatively low-pressure compressed air typically less than 150 psi) to generate an output pressure sufficiently intense to propel injectate efficiently and without imparting any substantial heat to the injectate. Rather than operating continuously to maintain a desired pressure, the air booster pump  32  stops once that pressure has been attained. Each air booster pump  32  is connected to one or more heads  34 . And preferably, but not necessarily, control valve  36  in a feed line  38  going from the high-pressure side  40  of the air booster pump  32  to one or more heads  34  opens to allow injectate on the high-pressure side  40  of the air booster pump  32  to flow through the nozzle or nozzles  42  of the one or more heads  34 . When this occurs, the pressure is lowered, and the air booster pump  32  operates only long enough to re-establish the desired pressure. 
     Preferably, but not necessarily, the control valve  36  is capable of directing injectate from the air booster pump  32  to the specific head or heads  34  which a user wishes to provide injection; alternately, however, a separate valve is located between the air booster pump  32  and each head  34  supplied with injectate by that air booster pump  32  so that a user may determine which heads  34  will be used for injection. 
     Alternatively, in lieu of either the control valve  36  or the separate valve between the air booster pump  32  and each head  34  supplied with injectate by that air booster pump  32 , a separate pilot valve activates, deactivates, and controls the pressure provided by a given air booster pump  32 . 
     The air booster pump  32  holds only a small quantity of injectate and preferably, but not necessarily, receives such injectate from a nearby supply reservoir  46 , minimizing the total quantity of injectate that must be within the machine. 
     Each head  34 , itself, has a number of unique features. 
     The head  34  is a hollow body having apertures  48  near the bottom into which one or more nozzles  42  may be releasably connected. Each nozzle  42  has an input end and an output end. Preferably, but not necessarily, the input end lies within the head  34  at a point with enough distance to the interior of the wall of the head  34  that any particles that may be within the injectate will tend to fall to a level below the input end of the nozzle  42  and, therefore, be unlikely to enter and clog the nozzle  42 . 
     The interior diameter of the nozzles  42  is preferably, but not necessarily, selected to be such that surface tension of a liquid injectate will preclude the injectate from passing through a nozzle  42  unless the air booster pump  32  has pressurized the injectate above atmospheric pressure. This diameter is preferably less than 0.025 inch. 
     Within the head  34  is, preferably, but not necessarily, located a hollow tube  52  which communicates with the feed line  38  from the air booster pump  32  so that any injectate entering the head  34  must do so through the tube  52 . Multiple apertures exist in the wall of the tube  52  that is perpendicular to the longitudinal access of the tube  52 ; preferably there is an aperture in the vicinity of each nozzle  42  in order to tend to equalize the pressure of the injectate at each nozzle  42 . Introduction of the injectate into a head  34  at multiple locations, rather than from a single location, tends to increase turbulence within the injectate inside the head  34  and, therefore, to minimize the tendency of any particles within the injectate to accumulate and block a nozzle  42 . 
     Again preferably, but not necessarily, a filter is located between the feed line  38  and any nozzle  42  associated with that head  34 . When the hollow tube  52  is employed, such hollow tube  52  communicates with such aperture; and the hollow tube  52 , preferably, but not necessarily, has, as the filter, a screen which removably surrounds the wall of the hollow tube  52  that is parallel to the longitudinal access of the hollow tube  52 . 
     The head  34  is preferably, but not necessarily, designed so that upon installation one point of the inside of the head  34  will be at substantially the highest elevation. Near such point the head  34  has an escape aperture  60  so that any gas within the injectate that enters the head  34  will tend to flow to and through such escape aperture  60 . Removal of gas from the injectate within the head  34  is important because, although liquid injectate is essentially incompressible, gas can be compressed; so, when the air booster pump  32  stops, injectate would not be forced through any nozzle  42  by the air booster pump  32  but would be by any entrapped, expanding compressed gas. 
     A return line  62  is preferably, but not necessarily, attached to the escape aperture  60  in order to return any liquid injectate that is forced through the escape aperture  60  by entrapped, compressed gas to the reservoir  46 . 
     Preferably, but not necessarily, the feed line  38  and the return line  62  are flexible in order to facilitate moving the head or heads to alternate locations. The feed line  38  and the return line  62  could, however, be inflexible. 
     Preferably, but not necessarily, a valve  64  is located in the escape aperture  60  (or the return line  62 ). This valve  64  may be a manually operated valve but is preferably an electronically actuated valve. 
     Each head  34  is preferably, but not necessarily, mounted to a surface termed the “work surface,”  66  which is preferably, but not necessarily, the top of a cabinet. Preferably, but not necessarily, the mounting is such that the head  34  may be rotated about one or more axes and preferably about three orthogonal axes. This is accomplished through any means that is well known in the art, such as by securing the head with a clamp that can be opened and then closed or loosened and then tightened. Additionally, it is preferable to have the height of the head above the work surface  66  adjustable. Again, this is accomplished through any means that is well known in the art, such as mounting the clamps on a bracket that can be raised or lowered, e.g., with a hydraulic cylinder or a rotatable screw. 
     When there are multiple, independently orientable heads  34 , a variety of optional techniques for injection exist. For example, injection can occur from multiple directions simultaneously or in timed succession; the angle of entry for the injection from one or more heads  34  can be changed simultaneously or in timed succession; offsetting forces of two or more injection heads  34  can be utilized to stabilize the position of the subject of the injection, precluding or minimizing the movement of the subject that can be caused when injection occurs from a single direction; and the pattern of injection produced by the nozzles  42  of different heads  34  can be overlapped to achieve a higher injection density at one time than could be obtained by using just one head  34 , because of physical limitations dictating the space required between adjacent nozzles  42 . 
     The top of the work surface  66 , which, as noted above, is preferably, but not necessarily, the top of a cabinet, is preferably, but not necessarily, sloped to collect excess injectate and use gravity to cause it to flow through a drain  68  and preferably, but not necessarily, a screen. The screen can be upstream from the drain  68  or within the drain  68 . Optionally, instead of just relying upon gravity, a reclamation pump could be placed in or adjacent to, and in fluid communication with, the drain  68 . And the drain  68  optionally could include a catch basin into which injectate reclaimed from the work surface  66  would first flow. 
     There exist a variety of options for providing injectate to the air booster pump  32 . Of course, a source  44  of injectate is connected to and in fluid communication with the input side  70  of the air booster pump  32 . 
     Preferably, but not necessarily, a filter  72  designated the main injectate filter is located between the source of injectate  44  and the air booster pump  32 , especially if pre-filtered injectate is not used. 
     If it is not desired to have a return line  62  from the head  34  and if it is not desired to reclaim injectate from the work surface  66 , either a container in which the injectate is delivered or a reservoir  46  into which the injectate is placed can serve as the source  44  of injectate. Gravity can cause the injectate to flow from the source to the air booster pump  32 . Preferably, but not necessarily, however, either the source is pressurized, by any means  74  that is well known in the art, with gas to cause the injectate to flow or a pump  76  is inserted between the source and the air booster pump  32 . This improves performance of the Machine for Injecting Liquids  30  and tends to preclude outgassing from the injectate which is caused when the air booster pump  32 , in the absence of a pressurized source  74  or a pump  76  between the source and the air booster pump  32 , creates a vacuum on its low-pressure side  70 . 
     When a pump  76  is inserted between the source and the air booster pump  32  and when there is a return line  62  or a drain  68  from the work surface  66  or both the return line  62  and the drain  68 , it is preferable, but not necessary, to have the return line  62  and the drain  68  flow into the container or the reservoir  46 , whichever serves as the source  44 . In this case, were the source pressurized, check valves could be employed in the return line  62  and the drain line  78 , in any manner that is well known in the art; but the reclamation pump would have to provide flow from the drain line  78 . And, as a further alternative when the reclamation pump stimulates flow from the drain line  78 , a line from the source could combine with the return line  62  and the drain line  78  utilizing check valves in any manner that is well known in the art with the combined line proceeding to the pump  76  between the source and the air booster  32  if such a pump  76  is employed and otherwise going to the low-pressure side  70  of the air booster pump  32 . 
     It is further preferable, but not necessary, to have the ability to remove the main injectate filter  72  while the Machine  30  is still operating. This would permit the main injectate filter  72  to be cleaned or replaced without interfering with production. 
     One example of a structure for accomplishing this is to have a line  80  from the source that branches into two parallel lines, each having a main injectate filter  72 . A valve at the point of branching or on-off valves  82  in each parallel line prior to the main injectate filter  72  select which parallel line will operate. The parallel lines could rejoin prior to or upon entering any pump. An alternate exemplary structure has an auxiliary reservoir  84  located downstream from the main injectate filter  72  prior to any pump. This permits the main injectate filter  72  to be removed when there is no injectate in the first reservoir  46  while sufficient injectate remains in the second reservoir  84  to supply the needs of the Machine  30  at least for the time that is required to replace the main injectate filter  72 . 
     Each head  34 , preferably, but not necessarily, has a first end  86  and a second end  88  as well as an aperture  90  designated the “cleaning aperture,” which is preferably, but not necessarily, located in either the first end  86  or the second end  88  of the head  34  or, most preferably, both ends  86  and  88  of the head  34 . As its name implies, the cleaning aperture  90  facilitates cleaning of the head  34 . A brush, a high-pressure flush, or a spray may be introduced to the inside of the head  34  through the cleaning aperture  90 . The cleaning aperture  90  is closed preferably, but not necessarily, with a valve located within the cleaning aperture  90 . Optionally, a cap designated the “end cap” is removably attached to the head  34  over the cleaning aperture  90 . This may be done in any manner that is well known in the art, such as by having mating threads in the cleaning aperture  90  and on the end cap. 
     Within or adjacent to the top of the work surface  66  is, preferably, but not necessarily, located an endless-belt conveyor  94 . The conveyor  94  moves subjects near the head or heads  34  so that such subjects can be injected. Preferably, but not necessarily, the belt  96  of the conveyor contains apertures  98  so that a head or heads  34  can even be mounted below the belt  96  as well as above or substantially even with the belt  96 . 
     Preferably, but not necessarily, the speed of the conveyor  94  is variable; movement of the conveyor  94  can be continuous or incremental; and preferably the conveyor  94  employs electronic braking to insure that the conveyor  94  is stopped rapidly and completely when desired. 
     Although the Machine  30  can be operated manually, it preferably, but not necessarily, includes a computer device such as a programmable logic controller. 
     The computer device, thus, preferably utilizes programmable microprocessors and includes the traditional features of a computer, such as a memory. 
     The length of the injection burst, injection pressure, and the delay between bursts can be programmed into the computer device by a user, although optional default settings can be placed into the computer device at the factory. The computer device is preferably, but not necessarily, capable of storing multiple programs that can be used when desired. Preferably, but not necessarily, the length of the injection burst can be varied from no injection to a continuous injection. 
     The computer device, furthermore, is preferably, but not necessarily, capable of controlling the movement of the conveyor  94  and synchronizing such movement with the injection burst in order to select the desired effect of the injection. For example, the computer device can, preferably, but not necessarily, cause injection to occur only when the conveyor  94  is stopped and thereby create virtually unnoticeable points of entry for the injectate into the subject; or, alternatively, the computer device can cause injection to transpire while the conveyor  94  is moving to create a slit in the subject that will result in mechanical tenderizing when the subject is material such as meat. 
     Optionally, the computer device may also be interfaced with various sensors, such as a sensor that detects the thickness of the subject. A program in the computer device then adjusts one or more injection parameters to accomplish a pre-selected goal with regard to the subject, e.g., attainment of a selected concentration of injectate within the subject. 
     Additionally, all valves in the Machine, including but not limited to, the valve in the cleaning aperture  90  and the valve in the escape aperture  60  can preferably, but not necessarily, be controlled by the computer device. When this is done for the valve in the escape aperture  60 , the computer device is preferably, but not necessarily, 
     programmed to open the valve in the escape aperture  60  for a specified duration after a specified number of injections. Experience with the Machine  30  will enable a user successfully to predict the rate of accumulation of gas and, therefore, the number of injections after which the valve in the escape aperture  60  should be opened as well as the duration for such opening, although again default settings can be placed into the computer at the factory. Alternatively, the computer device can be programmed with algorithms based upon formulae that are well known in the art to calculate the theoretical pressure anywhere on the high-pressure side  40  of the air booster pump  32 , e.g., in the feed line  38 . A pressure sensor then measures the actual pressure. The computer device is programmed to compare the actual and theoretical pressures. Since air within the portions of the Machine  30  that are in fluid communication on the high-pressure side  40  of the air booster pump  32  is generally responsible for the actual pressure being lower than the theoretical pressure, the computer device is programmed with a range below the theoretical pressure within which the actual pressure must be. The computer device is further programmed to actuate, i.e., open, the valve in the escape aperture  60  one or more times until the actual pressure has risen so that it is above the lower limit of the acceptable pressure range. And in a still further option when the electronically actuated valve is employed in the escape aperture  60 , a sensor is located in the head  34  near or, preferably, in the escape aperture  60 . This sensor may be any sensor that is capable of distinguishing between liquid and gas, such as an optical sensor or a pressure sensor. The sensor is connected to the electronically actuated valve and causes the electronically actuated valve to be in the open position whenever gas is detected by the sensor. 
     Also, when there are multiple heads  34 , some or all of the parameters can, preferably, but not necessarily, be varied independently for each head  34 . This may be done with or without a computer device, but it is more practical to employ a computer device for such purpose. 
     Preferably, but not necessarily, input by the user to the computer device is accomplished with a sealed touch panel because this can withstand a wet environment. Any other input device that can withstand a moist environment is also acceptable. And any input device known in the art could be used if kept a sufficient distance from the moist environment associated with the Machine. 
     Preferably, but not necessarily, the mounting of each head  34  is accomplished with gears and motors that are well known in the art so that each head  34  is moved in three axes as well as raised and lowered using the motors and gears. Such motors and gears are preferably, but not necessarily sealed as are their connections to power, using any technique that is well known in the art, so that they will not be impaired by a moist environment. Also preferably, but not necessarily, using any technique that is well known in the art, such as wires, radio frequency communication, or infrared communication, such motors and gears are remotely controllable. As is well known in the art, this can be done directly through the input device, preferably, but not necessarily, a touch panel or through an input device and the computer. 
     All features of the Machine  30  except the work surface  66 , the heads  34 , the motors and gears, and the lines are preferably, but not necessarily, contained within a sealed cabinet  100 . Moreover as discussed above, the work surface  66  is preferably, but not necessarily, the top of a cabinet; and, in the preferred embodiment, this would be the sealed cabinet  100 . 
     Anything which enters the sealed cabinet  100 , e.g., wires or lines, such as a line to fill an non-pressurized reservoir, preferably, but not necessarily, enter through apertures which are sealed, preferably, but not necessarily, with rubber gaskets. For maintenance, one or more doors  102  preferably, but not necessarily, exist in the outer surface of the cabinet  100 ; but these doors  102  and the sealed cabinet  100  incorporate a seal, preferably, but not necessarily one or more gaskets, around the opening or openings formed when the door  102  is not closed. 
     Optionally, in order to minimize the presence of microorganisms in the injectate, a source of ozone  104  is connected to a non-pressurized reservoir in any manner that is well known in the art. The ozone  104  is then allowed to bubble through the injectate in such reservoir. This may, for example, be accomplished by connecting the source of ozone  104  through a pressure regulator and valve to the reservoir near the bottom of such reservoir. And, as indicated above, this valve and, indeed, every valve associated with the Machine  30  are, preferably, but not necessarily controlled by the computer device. 
     Because the introduction of ozone  104  is somewhat consumptive of time, it is preferable, but not necessary, to have a non-pressurized reservoir in each of two parallel lines and to have one or more valves control which reservoir is receiving ozone and which is being used to supply injectate. This is done in a similar fashion as discussed above for the use of two main injectate filters. 
     Also, as discussed with respect to the main injectate filter, the two reservoirs could be in series with the upstream reservoir being used for introduction of ozone  104  into the injectate while the downstream reservoir supplies the operational needs of the Machine for injectate. 
     Similarly, the subject of injection is preferably, but not necessarily, treated with ozone  104  prior to injection. In the same manner as described above for the injectate, ozone  104  is bubbled through a water reservoir containing water. Then there are three options. The subject can be passed through the water reservoir, the water containing ozone can be transferred by any method that is well known in the art to a holding reservoir through which the subject is passed, or the water containing ozone can be sprayed on the subject by any method that is well known in the art. 
     Preferably, but not necessarily, any portion of the Machine  30  that will contact either the subject or the injectate must meet the food grade specifications that are well known in the art. 
     Also preferably, but not necessarily, a removable safety shield  106  covers the working surface  66  and heads  34  to such an extent that a user cannot touch the nozzles  42  or the stream of injectate. 
     Preferably, but not necessarily, this safety shield  106  is transparent. And preferably, but not necessarily, sensors or interlocks, in any manner that is well known in the art, determine when the safety shield  106  has been installed and preclude the Machine  30  from injecting whenever the safety shield  106  has not been installed. 
     It can be seen that the above-described needleless injection apparatus can take several preferred forms, depending on the application of use for the machine. However, in food manufacture or production facilities, there is an interest in a needleless injection apparatus and method for using that can be incorporated into a continuous production line. In addition, the needleless injection apparatus of the present invention must also incorporate features that permit the machine to be easily operated, maintained and cleaned within a continuous production environment. Further, the improved needleless injection apparatus of the present invention minimizes down time for cleaning between runs and reduces potential contamination of the injection subjects by eliminating exposure of the injection fluid to threaded connection points within the manifold head. 
     In light of the foregoing,  FIGS. 8 through 16  illustrate a further embodiment of a needleless injection apparatus  130  of the present invention.  FIG. 8  illustrates a front side of the needleless injection apparatus  130  which includes a cabinet  134 , a large catch basin  136 , an endless-belt conveyor system  138 , injection heads  140  and a control panel  142 . Further, the apparatus includes a primary fluid reservoir  144  that is removably connected to the cabinet  134 . It will be understood that the needleless injection apparatus  130  of the present invention can further include a safety shield attached to the cabinet  134  for protecting an operator from contacting the moving components or the injection spray while the apparatus is operating. 
     As shown in  FIGS. 8 and 9 , the cabinet  134  is of a generally box-like construction and includes a front  146 , a back  148 , a right end  150 , a left end  152 , a top  154  and a bottom  156 . Further, the cabinet  134  can include casters  158 . The cabinet  134  also contains a channel  160  formed integrally in the top  154  for capturing and directing excess fluid to the catch basin  136 . The catch basin  136  is integral with the cabinet  134  and extends outward from the right end  150  of the cabinet  134  to collect excess injection fluid. 
     The catch basin  136  contains a drain  162  which releases the collected injection fluid directly back into the primary reservoir  144 , or alternatively, to a drain line which is piped directly to a floor drain. Also, the catch basin  136  can instead be removably attached to the right end  150  of the cabinet  134  in any manner known to those skilled in the art that prevents any excess injectate from spilling onto unwanted surfaces or equipment. 
     Turning for the moment to  FIG. 10 , the back side of the injection apparatus  130  is shown. The back  148  of the cabinet  134  contains large doors  164 , door hinges  166 , a door sealing and locking mechanism  168 , a main power inlet  170 , multiple quick-connect air outlet ports  172  for powering external air actuated pumps or valves, and a feed inlet port  174  through which fluid pumped from the primary fluid reservoir  144  to the injection heads  140  must travel. The back  148  of the cabinet  134  further includes a compressed air inlet port  175  for supplying compressed air to the cabinet  134 . Further, it can be seen that the control panel  142  is mounted to the back  148  of the cabinet  134  with mounting post  177 . 
     Best shown in  FIG. 11 , the conveyor system  138  is mounted within the channel  160  in order to move injection subjects through the apparatus  130 , from the right end  150 , past the injection head  140 , to the left end  152  of the injection apparatus  130 . The conveyor system  138  includes a conveyor belt  176  having a plurality of apertures  178  (best shown in  FIG. 9 ) formed therein so that excess injection fluid can pass through the conveyor belt  176  to the channel  160 . Further, the apertures  178  allow a subject to be injected by an injection head  140  positioned at a point below the conveyor belt  176 . 
     The conveyor system  138  is mounted to the cabinet  134  using a support structure  180  and drive mechanism  182  (shown in  FIG. 16 ). While  FIG. 11  illustrates the conveyor system  138  mounted within the channel  160 , the conveyor system  138  can be mounted on top of or onto the cabinet  134  in any manner known to those skilled in the art that permits movement of the injection subject past the injection heads  140 . In addition, the conveyor system  138  may contain a sensor, such as an optical sensor, for sensing the location of the injection subjects along the conveyor belt  176 . These sensors can be remotely linked to a controller or computer to indicate when the subjects are in position to be injected or in position to be off-loaded from the conveyor belt  176 . 
     The injection heads  140  are affixed to the top  154  of the cabinet  134  by a mounting system  184 . The mounting system  184  includes a mounting post  186  and a bracket  188  which movably support each injection head  140 , permitting the injection head  140  to be raised or lowered to any vertical position along the mounting post  186 , including below the conveyor belt  176 . Preferably, the injection heads are positioned to be no more than two inches from the injection subject; however, any injection height may be used. 
     The mounting system  184  further permits each injection head  140  to be rotated about its center axis  190 , allowing the angle of the injection bursts to be varied. In addition, the mounting system  184  can be provided with set-screws  192  or other adjustment mechanism for further elevating the height of the injection head  140 . 
     Alternatively, the injection heads  140  may be mounted to the cabinet  134  in any location or in any manner that allows each injection head  140  to be moved about three orthogonal axes, including electronically automated mounting systems that are controllable via a remote controller or computer. In addition, while two injection heads  140  are shown, it will be appreciated that a single injection head  140  or more than two injection heads  140  may be required for a given injection application. 
     Referring next to  FIGS. 12 and 13 , a detailed view of the injection head  140  is shown. The injection head  140  includes a hollow, tubular member  194 , a plurality of injection nozzles  196  and end caps  198 ,  200 . The injection head and related components are preferably constructed of stainless steel; however, the injection head may be constructed of any material known to those skilled in the art capable of withstanding the high system pressures required to needlelessly inject subjects. 
     As illustrated in  FIG. 13 , the tubular member  194  has cylindrical, outer surface  202 , a top portion indicated generally at  204 , a bottom portion indicated generally at  206  and opposing open ends  208  and  210 . The open ends  208 ,  210  of the tubular member  194  include threads  212  for removably attaching the end caps  198 ,  200  to the tubular member  194 . The tubular member  194  further includes injection apertures  214  disposed along the bottom portion  206 . When the nozzles  196  are removed from the tubular member  194 , the injection apertures  214  and the open ends  208 ,  210  in the tubular member  194  can be used as cleaning apertures when cleaning of the apparatus  130  is required. Alternatively, cleaning of the nozzles  196  and the injection head  140  can occur with the nozzles  196  in place on the manifold. 
     The tubular member  194  further includes an escape aperture  216  disposed on its top portion  204  of near the end  210 . The escape aperture  216  is used as an air bleed/pressure relief port to prevent build-up of air within the injection head  140  during operation of the apparatus  130 ; thus, the escape aperture  216  is preferably at the point of highest elevation along the injection head  140 . A quick-connect fluid line  218  is attached to escape aperture  216  to evacuate air build-up in the injection head  140  during operation. 
     Best shown in  FIG. 13 , the injection nozzles  196  are removably attached to each of the injection apertures  214  by a retaining screw  197 . While the nozzles  194  are shown secured into the injection apertures  214  using a retaining screw, the nozzles  196  may be integral to the injection head  140  or otherwise removable attached to the injection apertures  214  in any manner known to those skilled in the art. 
     Referring again to  FIG. 12 , each injection nozzle  196  has an orifice  220  for delivery of the injection fluid to the subject. The orifice  220  in each injection nozzle  196  is preferably less than 0.025 inches and more preferably approximately 0.006 inches. The nozzles  196  and set screw  197  are removable for cleaning and can be easily changed depending on the subject to be injected and the desired injection objectives. In addition, consistent with the teachings of the present invention, it will be apparent to one skilled in the art that the orifice  220  in the injection nozzles  196  may be greater than 0.025 inches depending on the type and/or the thickness of the subject to be injected. 
     The nozzles  196  are constructed of sapphire, or any material known to those skilled in the art capable of withstanding the high-pressure fluid bursts required for the needleless injection of subjects. 
       FIG. 14  illustrates the fluid-in end cap  198  which is used to removably seal the open end  208  of the tubular member  194  closed. The end cap  198  includes a feed port  222  having a threaded inlet  224  and a threaded outlet  226  through which the injectate fluid pumped to the injection head  140  is first received. The threaded inlet  224  is sized to receive a fluid feed connection. The threaded outlet  226  is sized to receive open end  208 . 
     In addition, the end cap  198  includes a small compartment  228  bored into the feed port  222 , adjacent to the threaded outlet  226 . The end cap  198  further includes an O-ring  230  (shown in  FIG. 15 ) positioned within the threaded outlet  226  to ensure a tight seal between the end  208  of the tubular member  194  and the end cap  198 . 
     Likewise, an end cap  200 , shown in  FIGS. 12 and 13 , is used to removably seal the open end  210  of the tubular member  194  closed. The end cap  200  includes a threaded cavity  232  in the center of the end cap  200  and is sized to receive the end  210  of the tubular member  194 . Further, the end cap  200  includes an O-ring  234  to ensure a tight seal between the end  210  of the tubular member  194  and the end cap  200 . 
     The ends  208 ,  210  of the tubular member  194  are sealed for a production run by threading and hand tightening end caps  198 ,  200  onto the tubular member  194  so that the peripheral edge of each end  208 ,  210  abuts or contacts the O-rings  230 ,  234 , as shown in  FIG. 13 . Accordingly, during a production run, the incoming fluid does not contact any threading, grooves or pitting that may be present in either the end caps  198 ,  200  or the ends  208 ,  210 , thereby making cleaning easier to perform. 
     Further, because residual injection fluid does not become trapped within the threading or pass through it, the risk for fluid contamination is decreased. In addition, the configuration of the injection head  140  may increase the useful life of the injection head  140 , as threads or grooves exposed to acidic conditions (cleaning fluid or injectate) tend to pit easily and rust. 
     The O-rings  230 ,  234  can be constructed of a material such as those sold under the trademark TEFLON by DuPont, Inc. or its licensees, EPDM (Ethylene Propylene Diene Monomer), silicone, rubber, or any other material appropriate for the particular application and known to those skilled in the art that can seal the ends  208 ,  210  of the tubular member  194  closed. 
     Referring back to  FIG. 13 , a first filter  236  is shown. The filter  236  is generally a hollow tube having a cylindrical exterior surface  238  and opposing ends  240  and  242 . The end  240  is open to channel the fluid entering through the feed port  222  in the end cap  198  directly into the filter  236  when it is installed within the injection head  140 . The length and width of the filter  236  are selected to permit the filter  236  to fit within the injection head  140 . 
     The filter  236  includes apertures  244  formed in the surface  238  along the length of the filter  236 . The apertures  244  can be located anywhere along the longitudinal or circumferential extent of the filter  236 . The number and placement of the apertures  244  in filter  236  is dependent on the flow volume required for a given injection run, which is in turn also affected by the number of injection nozzles used, the type of injectate fluid used, the required injection time, the required burst pressure or a combination thereof. 
     The filter  236  further includes an O-ring  246  near the end  240  for removably sealing the filter  236  relative to the feed port  222  when the filter  236  is installed within the injection head  140 . 
     Typically, the filter  236  is installed into the injection head  140  with the end cap  200  already in place over the open end  210  of the tubular member  194 . The end  242  of the filter  236  is inserted into the tubular member  194  and is positioned such that it rests on and is maintained within the cavity  232  in the center of the end cap  200 , as shown in  FIG. 13 . When the end cap  198  is installed on the end  208  of the tubular member  194 , the end  240  of the filter  236  rests and is maintained within the small compartment  228  over feed port  222 . The O-ring  246  in the end  240  of the filter  236  threadlessly seals the injectate filter  236  in place. 
     The filter  236  can, alternatively, be installed into the injection head  140  before the end caps  198 ,  200  are installed on the injection head  140  with the end caps  198 ,  200  being positioned on to the injection head  140  after the filter  236  has been placed inside. 
     The injectate filter  236  prevents nozzle plugging without being integral to the fluid-in end cap and without requiring a steel mesh encasing or another filter-type material affixed to the filter  236 . Further, the filter  236  is a stand-alone filter that rests within the injection head  140 , allowing easy change-out of the filter  236  during breaks in a continuous operation or during cleaning. 
     In addition, the filter  236 , by virtue of the O-ring  246  seal, reduces the risk of contamination of the injectate fluid and the needleless injection apparatus  130  by preventing the fluid from contacting any threading present in the filter  236 , the end caps  198 ,  200 , or the tubular member  194 . The filter  236  may also increase the useful life of the injection head  140  and/or the end caps  198 ,  200  over other filter configurations, as threads or grooves exposed to acidic conditions (cleaning fluid or injectate) tend to pit easily and rust. 
     Referring next to  FIG. 13 , there is shown a second, alternate filter  248  for the needleless injection apparatus  130  of the present invention. The filter  248  is generally a disk-shaped element having a front side  250  and a back side  252 . The filter  248  includes a flat, peripheral edge  254  and a plurality of apertures  256  formed within the filter  248 . 
     To install the filter  248  into the injection head  140 , the back side  252  of the filter  248  is placed into the end cap  198 , without O-ring  230  present within the end cap  198 , such that the feed port  222  is covered by the filter  248 . The O-ring  230  is then placed over the disk filter  248  so that the O-ring  230  engages the filter&#39;s peripheral edge  254 . The end cap  198  is then threaded onto the end  208  of the tubular member  194 , thereby threadlessly sealing the filter  248  in place within the injection head  140 . During operation, injectate fluid passes through the apertures  256  in the filter  248  to remove particulate in the injection fluid. 
     It will appreciated by those skilled in the art that the injection head  140  may be of any shape or size, provided that adequate fluid pressure can be achieved at the outlet of the nozzles  196  to provide for the needleless injection of the subject. For example, the injection head  140 , rather than being tubular in shape, can be round or generally cylindrical in shape having apertures within any surface of the cylinder. In addition, the injection head  140  can have injection nozzles that are formed integrally therein, rather than including a tubular member with apertures for removable nozzles. Therefore, the injection head can be a single piece component, lending itself to easier cleaning and assembly. 
     Further, the injection head  140  may contain apertures  214  and/or nozzles  196  configured in any pattern desirable for a given injection application. For example, the nozzles may be concentrated in a circular pattern or a rectangular pattern, depending on the type of injection subject. 
     Turning next to  FIG. 16 , the primary reservoir  144  is a generally rectangular container having four sides  258 , an open top  260  and a bottom  262  supported by casters  264 . The bottom  262  of the primary fluid reservoir  144  is sloped downward to the center  266  of the bottom  262  such that the center  266  is the lowest point in the bottom  262  of the reservoir  144 . Accordingly, any particulate matter present in the injectate fluid will accumulate at the center  266  of the bottom  262 . A cleaning aperture  268  is formed within the center  266  of the bottom  262  of the reservoir  144 . Further, a cleaning valve  270  is attached to the cleaning aperture  268  to facilitate draining and cleaning of the reservoir  144 . 
     A fluid-feed aperture  272  is formed within the sloped bottom  262  of the primary fluid reservoir  144  at a point higher up along the bottom  262  than the center  266  to minimize the introduction of unwanted particulate into the system. A fluid-feed air pump  274  is attached to the fluid-feed aperture  272 . The air pump  274  draws fluid from the primary reservoir  144  and pumps the fluid to a main injectate filter  276  via a fluid line  278 . 
     The fluid leaving the main injectate filter  276  enters the cabinet  134  via a fluid line  280 , ultimately feeding the injection head  140 . The main injectate filter  276  may be mounted to the reservoir  144 , to the cabinet  134 , may be free standing or may be mounted to the apparatus  130  in any way known to those skilled in the art. Further, there may be more than one main injectate filter, as described above, that permits filter change-out during continuous operation of the injection apparatus  130 . For added food safety and to prevent clogging, additional fluid filters can be positioned anywhere within the fluid path of the apparatus  130 . 
     The primary fluid reservoir  144  further contains a float valve  282  for replenishing the volume of injectate fluid within the reservoir  144 . The float valve  282  may automatically open to refresh the injectate supply within the primary fluid reservoir  144  via another injectate source or a secondary reservoir when the fluid level within the primary fluid reservoir  144  reaches a specified level. Alternatively, the float valve  282  may be combined with a level sensor that will indicate via the control panel  142  that the level of fluid in the primary fluid reservoir  144  is low, permitting an operator to replenish the fluid remotely via the control panel  142 . 
     Further, while both the primary fluid reservoir  144  and the cabinet  134  are shown generally rectangular in shape, it is apparent that the shape of either the primary fluid reservoir  144  or the cabinet  134  or both can be cylindrical or any geometrical shape. 
       FIG. 16  further illustrates the back  148  of the cabinet  134  showing the doors  164  open. As can be seen, the fluid line  280  feeds two high-pressure air pumps  284  mounted within the cabinet  134 . In turn, the air pumps  284  feed injectate to a high-pressure manifold system  286  which includes multiple fast-acting, electronically actuated solenoid valves  288 . A pressure sensor  290  for monitoring the pressure output of each air pump  284  is also located within the manifold system  286 . 
     The solenoid valves  288  are used to control the timing and duration of injection bursts and evenly distribute the injectate fluid between the injection heads  140 . It will be appreciated by those skilled in the art that the number or air pumps  284  and the number of solenoid valves  288  will vary depending on the number of injection heads  140  used in the machine. Further, the need to ensure a steady stream of fluid to the injection subject without experiencing a pressure drop or supply hesitation during an injection burst also will dictate the number of air pumps used in the machine. 
     Further shown in  FIG. 16 , an air pressure regulator  292  and a filter assembly  294  are mounted within the cabinet  134  for regulating the compressed air supply used to operate the air pumps  284 . The pressure regulator  292  permits an operator to adjust the pressure of the air going to the air pumps  284  thereby influencing the outlet fluid pressure from the air pumps  284 . In addition, the valves  293  control the air flow to the pumps  284 . In addition, a second air pressure regulator  295  is included within the cabinet  134  for regulating the air pressure supply to the external pump  274 , or any additional external equipment requiring compressed air. 
     Pressure regulator  292  may be electronically actuated and linked with the pressure sensor  290 , allowing an operator to automatically adjust the injection burst pressure via the control panel  142 , or recall a saved program which automatically adjusts the regulator  292  for a given injection subject or at a given output pressure. Further, the air pressure regulator  292  allows an operator to correct both an unsteady injection stream or variations in compressed air supply pressure while the machine is running. In addition, pressure sensor  290  and pressure regulator  292  can be used to automatically adjust the air pressure. In this instance, the required air pressure will be maintained and controlled automatically via the controller, requiring no operator intervention. 
       FIG. 16  further shows how the fluid lines  218  from each escape aperture  216  of the injection head  140  enter the cabinet  134 . As can be seen, a fast-acting solenoid valve  296  is connected to each line  218  for quickly releasing any air build-up in the injection head  140  during operation. Since injection fluid may also be released through the escape aperture  216 , fluid exiting the valves  296  may be piped to a drain or recycled back into the primary reservoir  144  or another injectate source. Importantly, the valves  296  are not located within each escape aperture  216 ; rather, the valves  296  are located within the cabinet  134  at the end of fluid lines  218 , thereby eliminating exposure of the valves to a damp working environment. Also, the valves  296  can be automated and programmed to open at predetermined intervals for a given injection subject without requiring an affirmative action by the operator, simplifying operation of the injection apparatus  130 . 
     The conveyor drive mechanism  182  is positioned within the cabinet  134  along with any components of the conveyor support structure  180  necessary for using the conveyor system  138 . 
     Referring back to  FIG. 8  for the moment, the control panel  142  is shown attached to the cabinet  134 . The control panel  142  includes a sealed touch screen  298  which is linked to a programmable logic controller (PLC)  300  within the cabinet  134  (shown in  FIG. 16 ) for storing and controlling operational information. A button  302  is also included on the control panel  142 . The button  302  is rotated in the clockwise direction to turn the machine on. The button  302  is also an emergency stop button that instantly stops the machine when depressed. Also, when a production run is over, the button  302  will be depressed to stop the machine. 
     The PLC  300  may control all process variables including complete synchronization of the conveyor system  138  with the injection bursts to be delivered to the subject. This can include automatic control of the injection pressure, duration of the bursts, spacing between injection bursts and timing of the injections. Further, every valve used in the injection apparatus  130  may be automated using the PLC  300 . Variables such as the air pressure supplied to the air pumps  284 , the output pressure of the air pumps  284 , the direction of injection spray, the orientation of the injection heads  140  or the fluid level in the reservoir  144  may be monitored and controlled by the PLC  300 , thereby simplifying both operation of the machine and integration of the machine into a continuous production line. While a programmable logic controller is disclosed, one skilled in the art will appreciate that any computer control device may be used to store injection and process variables and/or operate the machine. 
     It can be seen that the present invention includes a method of using a substantially uniform, high-pressure injection burst to needlelessly inject a subject with injectate fluid. In this way, damage to the external surfaces of the subject is minimized. The present invention also includes a method of delivering injection fluid to a subject using substantially uniform, high-pressure injection bursts of a sufficient pressure to needlelessly add flavor, color, preservatives, binders, antimicrobial solutions and/or tenderize an injection subject without significant damage to the external surfaces of the injection subject. 
     Accordingly, referring to  FIGS. 8 through 16 , operation of the needleless injection apparatus  130  of the present invention will now be described. First, an operator uses the touch screen  298  to retrieve from the PLC  300  a stored set of process variables for a given injection subject or for a given injection effect. The preprogrammed process variables can include control of the injection pressure, duration of the injection bursts, spacing between injection bursts, timing of the injections, the output pressure of the air pumps  284 , the direction of injection spray, the orientation of the injection heads  140 , the number of injection subjects or any other information necessary to inject a given type of subject. If no predetermined program exists for the production run, an operator may enter variables via the touch screen  298  and/or adjust the variables during the production run in accordance with the required injection effect to be achieved by the machine. 
     The reservoir  144  is filled with the desired injection fluid. In addition, if a secondary reservoir is used, the secondary reservoir must be also filled with injection fluid. When the primary reservoir reaches a low level, the controller may be programmed to automatically replenish the primary reservoir from the secondary reservoir. Accordingly, no operator intervention will be required to maintain a high level of fluid within the primary reservoir. 
     Alternatively, if the primary reservoir  144  becomes low, the touch screen  298  may indicate to the operator that the level is low and will permit the operator to refresh the injectate fluid automatically using the controller. In addition, the operator can pause the operation of injection apparatus  130  and manually refill the primary reservoir  144 . 
     During operation, injection fluid will be pumped from the reservoir  144  through the fluid feed aperture  272  to the main injectate filter  276  by the feed pump  274 . The fluid then flows from the main injectate filter  276  to the low-pressure side of the injection air pumps  272  within the cabinet  134 . The air pumps  284  pump the fluid to the injection manifold system  286 . At this time, the output pressure of the fluid is measured by the sensor  290  to determine if the required injection pressure has been attained. If not, the program automatically adjusts the air pressure to the pumps  284  using the air pressure regulator  292 , or the operator may adjust the regulator  292  via the touch screen  286 . The fluid is evenly distributed among the injection heads  140  by the injection manifold  286  which directs fluid to the high-pressure solenoid valves  288 , ensuring that each injection head  140  receives an adequate and substantially equal flow of fluid. 
     Injection subjects are placed on the conveyor belt  176  near end  150  either manually by an operator, or preferably, automatically by another conveyor system or machine in the production line. The injection subject is moved towards the injection heads  140  and is injected according to the desired results. When the subject is in place, solenoid valves  288  in the manifold system  286  open allowing fluid to be delivered to the subject through the nozzles  196  on each injection head  140 . After an injection burst is complete, the valves  288  are closed. 
     Periodically, the fast-acting solenoid valves  296  connected to the escape apertures  216  are opened to relieve any air build-up within the injection heads  140 . If the valves  296  are not programmed to open at a given interval, the operator can use the touch screen  298  to cause the valves  296  to open periodically. 
     Subjects can be injected in place, with the conveyor belt  176  stopped, or the subjects can be injected while the conveyor belt  176  is moving relative to the injection heads  140 , depending on the desired results. 
     Excess injection fluid flows into the channel  160  and then into the catch basin  136 . If recycling of the injection fluid is desired, the catch basin may drain directly back into the primary reservoir  144  or into a reserve reservoir. Alternatively, the excess injection fluid may be piped directly to a drain. 
     After injection, the injection subjects may be off-loaded automatically from the conveyor belt  176  for further processing and/or packaging. However, off-loading of subjects can be performed manually.