Patent Publication Number: US-RE38342-E

Title: Apparatus for detecting leaks in a pressurized air conditioning or refrigeration system

Description:
This application is a continuation of U.S. patent application Ser. No. 09/557,831, filed Apr. 26, 2000, now U.S. Pat. No. 6,253,810, which is a continuation-in-part of U.S. patent application Ser. No. 09/535,368, filed Mar. 24, 2000, now U.S. Pat. No. 6,186,197, which is a continuation of U.S. Application Ser. No. 09/003,021, filed Jan. 5, 1998, now U.S. Pat. No. 6,050,310, which is a continuation-in-part of U.S. patent application Ser. No. 08/710,486, filed Sep. 18, 1996, now U.S. Pat. No. 5,826,636 the entire contents of which are hereby incorporated by reference and relied upon. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The instant invention relates generally to the field of pressurized fluid systems and more specifically it relates to an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system. The purpose of the apparatus is to provide the technician with a simple method of injecting a predetermined amount of a secondary fluid, e.g., a fluorescent dye, and/or lubricant into a pressurized system. 
     2. Description of the Prior Art 
     Numerous pressurized fluid systems have been provided in the prior art that are adapted to operate optimally within a certain pressure range. If the internal pressure falls below this range, the system needs to be recharged with an appropriate lubricant. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described. 
     There does not presently exist a cost effective way to accomplish the task of inserting a predetermined amount of lubricant into a pressurized system. Added to this, is the fact that when a technician arrives on site they are faced with a myriad number of systems with service connection access ranging from the accessible to the acrobatic and often cramped working conditions. 
     Some systems contain a combination of fluids. For example, air conditioning and refrigeration systems generally contain a refrigerant (the primary fluid) in combination with a lubricating oil (the secondary fluid) for the compressor and other critical components. The lubricating oil is generally present in fairly low quantities, usually less than 5% of the total fluid. The present invention provides for the introduction of these and other secondary fluids into air conditioning or refrigeration systems charged with the primary fluids in order to detect leaks in the pressurized systems. 
     Furthermore, air conditioning or refrigeration system leaks are difficult to locate because refrigerants are generally odorless and colorless gases. The present invention provides for a device and method for injecting a small amount of a concentrated fluorescent additive or dye into the system, thereby making the leaks easier to find. The fluorescent dye can be injected into the system with the present device or they can be placed in the systems at the original equipment manufacturing facility prior to the system being put into service. These air conditioning and refrigeration systems are closed loop recirculating systems and the secondary fluid is a lubricant that also travels throughout the system while in operation. The dye will travel throughout the system and leak out with the refrigerant. The dye will leave a stain that can be further enhanced with the use of an ultraviolet (UV) lamp. The UV wavelength of light will excite the dye allowing the operator to more easily identify the exact location of the leak. The device can also be used to add the appropriate lubricant to the air conditioning or refrigeration system without stopping the system and without any special equipment. 
     A cartridge that is at or about atmospheric pressure while not in use contains the concentrated fluorescent dye and/or lubricant. The cartridge is connected to the device of the present invention in way that will raise the pressure of the dye above that of the operating system. The connection between the device and the operating system must be airtight. The connection can be a quick coupler, thread or other means of positive, sealed connection. 
     SUMMARY OF THE INVENTION 
     The preferred embodiment of the present invention is for an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system and includes an injection device with a receptacle portion for receiving a disposable or reusable lubricant canister and a connector assembly for attaching the lubricant canister to the pressurized system. The lubricant canister contains lubricant and/or fluorescent dye. It is a further aim of the present invention not to limit the mechanical means of lubricant and/or fluorescent dye delivery just to hand pressure, but to provide other embodiments using various types of hand tools and structures to accomplish the delivery of the lubricant and/or fluorescent dye to the pressurized system. 
     More specifically, the present invention is for an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system, comprising a canister containing a second fluid, where the secondary fluid comprises a fluorescent dye; means for fluidly coupling the canister to the pressurized system; and means for forcing the secondary fluid out of the canister, through the fluidly coupling means and into a service valve of the pressurized system. 
     In a preferred embodiment, the canister includes a tubular casing for holding the secondary fluid therein; a threaded nozzle integral with and extending out from a first end of the tubular casing to engage with one end of the fluidly coupling means; and a piston inserted within an open second end of the tubular casing to engage with a secondary fluid forcing means. 
     In a more preferred embodiment, the tubular casing is fabricated out of transparent material and includes a plurality of gradient markings to aid in accurately dispensing a predetermined amount of the secondary fluid therefrom. In another embodiment, the canister further includes a threaded cap, to engage with the threaded nozzle when the canister is not in use, so as to prevent leakage of the secondary fluid through the threaded nozzle. 
     In another preferred embodiment, the fluidly coupling means is a connector assembly having a first end connected to the threaded nozzle of the canister and a second end connected to the service valve of the pressurized system. In a more preferred embodiment, the connector assembly includes a flexible conduit; a thread on the first end of the flexible conduit, to engage with the threaded nozzle of the canister; and a release valve on a second end of the flexible conduit, to engage with the service valve of the pressurized system. 
     In another preferred embodiment, the connector assembly further includes a one-way check valve at the first end of the flexible conduit, which prevents any material from back flushing into and contaminating the secondary fluid in the canister. 
     In yet another preferred embodiment, the release valve includes a closeable valve, which prevents any material from back flushing into the flexible conduit from the service valve of the pressurized system, and to allow the release valve to disconnect from the service valve of the pressurized system, to prevent leakage of the secondary fluid therefrom. 
     In more preferred embodiments, the release valve includes a snap lock fitting to engage with the service valve of the pressurized system or includes a threaded fitting to engage with the service valve of the pressurized system. 
     In another more preferred embodiment, the secondary fluid forcing means is an injection device. In yet another more preferred embodiment, the injection device includes a housing having a receptacle portion to receive the canister therein; and a drive mechanism to force the piston into the tubular casing, to cause the secondary fluid to exit the threaded nozzle through the fluidly coupling means, past the service valve, and into the pressurized system. 
     In another preferred embodiment, the drive mechanism includes a hand grip integral with and extending downwardly on the housing; a trigger pivotally mounted to the housing adjacent the hand grip; a central drive shaft extending longitudinally through the housing and transversely past a pivotal portion of the trigger; a cylindrical head on an inner end of the central drive shaft, to engage with the piston of the canister; a first pawl spring biased on the central drive shaft forward the pivotal portion of the trigger; and a second pawl spring biased on the central drive shaft rearward the pivotal portion of the trigger, the second pawl having a tongue extending out through a rear wall of the housing above the hand grip, so that when the trigger is squeezed, the first pawl will move into contact with the central drive shaft, to push the central drive shaft forward with the cylindrical head making contact with the piston, while the second pawl prevents reverse movement of the central drive shaft, until the tongue disengages the second pawl, allowing the central drive shaft to be pulled back to a desired position. 
     In a more preferred embodiment, the drive mechanism includes a hand grip integral with and extending downwardly on the housing; a trigger pivotally mounted to the housing adjacent the hand grip; a central drive shaft extending longitudinally through the housing and transversely above a pivotal portion of the trigger, the central drive shaft having a plurality of teeth extending therealong; a cylindrical head on an inner end of the central drive shaft, to engage with the piston of the canister; and a pawl pivotally mounted between the pivotal portion of the trigger and the housing, so that when the trigger is squeezed, the pawl will move into contact with the teeth on the central drive shaft, to push the central drive shaft forward with the cylindrical head making contact with the piston. 
     In another more preferred embodiment, the drive mechanism includes a second pawl spring biased in the housing to make contact with the teeth on the central drive shaft forward the first pawl, to prevent reverse movement of the central drive shaft. 
     In yet another more preferred embodiment, the drive mechanism includes a stationary nut mounted vertically within a rear wall of the housing; an elongated threaded rod extending longitudinally through the stationary nut; a cylindrical head on an inner end of the elongated threaded rod, to engage with the piston of the canister; and means on an outer end of the elongated threaded rod for rotating the elongated threaded rod through the stationary nut and moving the elongated threaded rod with the cylindrical head forward, to make contact with the piston. 
     In another preferred embodiments, the rotating means is a bolt head which can be turned by an open end and box wrench, is a socket head which can be turned by a ratchet socket wrench or is a handle rod extending transversely through the outer end of the elongated threaded rod which can be turned by a hand of a person. 
     In another preferred embodiment, the drive mechanism includes a rear chamber formed within the housing and having an inlet port to allow compressed gas to enter the rear chamber; a central drive shaft carried longitudinally within the tubular casing of the canister; a cylindrical head on an inner end of the central drive shaft, to engage with the piston; and a transverse drive plate on an outer end of the central drive shaft within the tubular casing adjacent the rear chamber, so that when the compressed gas is introduced through the inlet port into the rear chamber, the transverse drive plate will push the central drive shaft forward with the cylindrical head to make contact with the piston. 
     The present invention also discloses a canister or cartridge for charging a closed, pressurized air conditioning or refrigeration system with a fluid. The cartridge comprises a closed, non-pressurized cylindrical cartridge, where the cartridge has two ends, a first open end and a second open end, where the first open end comprises an inner nozzle which connects to the system being charged and an outer nozzle; a predetermined amount of the fluid; and a piston sealably disposed with the second open end of the cartridge, where the cartridge is adapted to connect sealably and releasably to the pressurized air conditioning or refrigeration system to form a closed binary system. 
     In a preferred embodiments of the cartridge, the fluid comprises a lubricant for the air conditioning or refrigeration systems; the fluid comprises a fluid dye for the air conditioning or refrigeration systems; or the fluid comprises a lubricant and a fluid dye for the air conditioning or refrigeration systems. 
     In other preferred embodiments of the cartridge, the fluid is maintained in the cartridge at about ambient pressure; and/or the cartridge is fabricated out of transparent material and includes a plurality of gradient markings. 
     In yet other preferred embodiments of the cartridge, the inner nozzle is surrounded by an internal thread; the outer nozzle is surrounded by an external thread; the outer nozzle comprises a threaded cap for engagement with the external thread; and/or the inner nozzle is surrounded by an internal thread and the outer nozzle is surrounded by an external thread. 
     In still other preferred embodiments of the cartridge, the piston further comprises an O-ring; or the piston further comprises a recessed double O-ring. 
     The present invention also discloses a method for detecting leaks in a pressurized air conditioning or refrigeration system. The method comprises the steps of charging the pressurized air conditioning or refrigeration system with a fluorescent dye with the apparatus of the present invention; inspecting the pressurized air conditioning or refrigeration system for leaks of the fluorescent dye from the pressurized air conditioning or refrigeration system; and detecting any leaks in the pressurized air conditioning or refrigeration system. In a preferred embodiment, the inspecting is done with ultraviolet light. 
     Thus, a primary object of the present invention is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that will overcome the shortcomings of the prior art devices. 
     Another object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that will allow a technician to inject a predetermined amount of lubricant and/or fluorescent dye into the pressurized system. 
     It is yet a further object of the invention to provide a method and apparatus for charging a pressurized air conditioning/refrigeration line with a lubricant and/or fluorescent dye from a closed, non-pressurized charging cartridge containing a predetermined amount of such lubricant and/or fluorescent dye. 
     An additional object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system which can be readily carried to a site, be easily operated, and can deliver a measured amount of lubricant and/or fluorescent dye into the pressurized system. 
     A further object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that is simple and easy to use. 
     A still further object is to provide an apparatus for detecting leaks in a pressurized air conditioning or refrigeration system that is economical in cost to manufacture. 
     It is yet a further object to present an apparatus and method for detecting leaks in air conditioning or refrigeration systems by injecting a fluorescent dye into the systems and then inspecting the system for leaks of the fluorescent dye from the systems. 
     Further objects of the invention will appear as the description proceeds. 
     To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     Various other objects, features and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein; 
     FIG. 1 is a side view of a first embodiment of the present invention. 
     FIG. 2 is an enlarged side view of the injection device shown in FIG.  1 . 
     FIG. 3 is a cross sectional view taken along like  3 — 3  in FIG.  2 . 
     FIG. 4 is an enlarged side of the lubricant canister in FIG.  1 . 
     FIG. 5 is a cross sectional view taken along line  5 — 5  in FIG.  4 . 
     FIG. 6 is a side view of the connector assembly in FIG.  1 . 
     FIG. 7 is a top view taken in the direction of arrow  7  in FIG.  6 . 
     FIG. 8 is an end view taken in the direction of arrow  8  in FIG.  6 . 
     FIG. 9 is a side view of a second embodiment of the connector assembly. 
     FIG. 10 is an end view taken in the direction of arrow  10  in FIG.  9 . 
     FIG. 11 is a top view taken in the direction of arrow  11  in FIG.  9 . 
     FIG. 12 a perspective view of a second embodiment of the injection device. 
     FIG. 13 is a cross sectional view taken along line  13 — 13  in FIG.  12 . 
     FIG. 14 is an enlarged cross sectional view of an area in FIG. 13 as indicated by arrow  14 . 
     FIG. 15 is a cross sectional view similar to FIG. 13, showing a single pawl mechanism to propel the toothed central shaft in the injection device. 
     FIG. 16 is a perspective view of a third embodiment of the injection device. 
     FIG. 17 is a crossectional view taken along line  17 — 17  in FIG.  16 . 
     FIG. 18 is a perspective view similar to FIG. 16, showing a socket wrench to turn the operating screw in the injection device. 
     FIG. 19 is a perspective view similar to FIG. 18, showing a transverse handle to turn the operating screw in the injection device. 
     FIG. 20 is a cross sectional view of a fourth embodiment of the injection device, whereby compressed gas is introduced within a chamber to drive the piston forward in the lubricant canister. 
     FIGS. 21A-F show a preferred embodiment of the cartridge of the present invention. FIG. 21A is a front view of the cartridge. FIG. 21B is a back view of the cartridge. FIGS. 21C and 21D are the left and right side view respectively, of the cartridge. FIG. 21E is a top view and FIG. 21F is a bottom view of the cartridge. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, FIG. 1 illustrates the present invention being an apparatus  22  for detecting leaks in a pressurized air conditioning or refrigeration system  24 . With regard to the reference numerals used, the following numbering is used throughout the various drawings figures. 
       22  charging apparatus 
       24  pressurized system 
       26  canister of  22   
       28  fluidly coupling facility of  22   
       30  lubricant or secondary fluid forcing assemblage of  22   
       32  lubricant and/or fluorescent dye of  26   
       33  central nipple or inner nozzle 
       34  service valve of  24   
       35  internal thread 
       36  tubular casing of  26   
       37  outer nozzle 
       38  threaded nozzle of  26  on  36   
       39  external thread 
       40  piston of  26  in  36   
       42  transparent material for  36   
       44  gradient marking on  36   
       46  threaded cap of  26  on  38   
       47  connector assembly for  28   
       48  flexible conduit of  47   
       50  threaded fitting of  47  on  48   
       52  release valve of  47  on  48   
       54  one-way check valve of  47   
       56  closeable control knob or valve of  52   
       58  snap lock fitting of  52   
       60  threaded fitting of  52   
       62  injection device for  30   
       64  housing of  62   
       66  receptacle portion of  64   
       68  drive mechanism of  30   
       70  hand grip of  68   
       72  trigger of  68   
       74  central drive shaft of  68   
       76  cylindrical head of  68  on  74   
       78  first pawl of  64   
       80  spring of  78   
       82  second pawl of  64   
       84  spring of  82   
       86  tongue of  82   
       88  teeth on  74   
       90  first pawl pivotally mounted between  72  and  64   
       92  second pawl on  64   
       94  stationary nut of  68   
       96  elongated threaded rod of  68   
       98  rotating structure of  68  on  96   
       100  bolt head for  98   
       102  open and wrench 
       104  socket head for  98   
       106  ratchet socket wrench 
       108  handle rod for  98   
       110  rear chamber of  68  in  64   
       112  inlet port of  110   
       114  transverse drive plate of  68   
     The apparatus  22  for detecting leaks in a pressurized air conditioning or refrigeration system  24  comprises a lubricant canister  26 . A facility  28  is for fluidly coupling the lubricant canister  26  to the pressurized system  24 . An assemblage  30  is for forcing lubricant and/or fluorescent dye  32  out of the lubricant canister  26 , through the fluidly coupling facility  28  and into a service valve  34  of the pressurized system  24 . 
     The lubricant canister or cartridge  26 , as shown in FIGS. 1,  4 ,  5 ,  13 ,  14 ,  15 ,  17  and  20  includes a tubular casing  36  for holding the lubricant and/or fluorescent dye  32  therein. A threaded nozzle  38  is integral with and extends out from a first end of the tubular casing  36 , to engage with one end of the fluidly coupling facility  28 . A piston  40  is inserted within an open second end of the tubular casing  36 , to engage with the lubricant forcing assemblage  30 . 
     The tubular casing  36  can be fabricated out of transparent material  42  and can include a plurality of gradient markings  44 , to aid in accurately dispensing a predetermined amount of the lubricant and/or fluorescent dye  32  therefrom. The lubricant canister  26  further includes a threaded cap  46 , as shown in FIGS. 4 and 5, to engage with the threaded nozzle  38  when the lubricant canister  26  is not in use, so as to prevent leakage of the lubricant and/or fluorescent dye  32  through the threaded nozzle  38 . 
     In a preferred embodiment of the lubricant canister or cartridge  26 , as shown in FIG. 21, a central nipple or inner nozzle  33  is integral with and extends out from the first end of the tubular casing  36 , to engage with one end of the fluidly coupling facility  28 . The central nipple or inner nozzle  33  is surrounded by an internal threaded  35  to facilitate engagement with one end of the fluidly coupling facility  28 . The lubricant canister or cartridge  26  further includes an outer nozzle  37  surrounded by an external thread  39  to engage with a threaded cap when the lubricant canister  26  is not in use, so as to prevent leakage of the lubricant and/or fluorescent dye  32  through the threaded nozzle. The external threads  39  are fitted for a drip cap with a standard size. 
     In practice, the central nipple or inner nozzle  33  can be made to extend slightly beyond the end of the outer nozzle  37 . A cap with an induction seal, which seals on the central nipple or inner nozzle  33 , can be used. These caps are lined with tinfoil, so that a heated, sealed end results which is able to withstand pressure and which seals directly to the lubricant or dye, if there is any present. 
     The design of the internal thread  35  allows a threaded check valve to mate with and to force the sealing area down the central nipple or inner nozzle  33 . The central nipple  33  is tapered slightly to allow easy installation and sealing with an O-ring on the inside of the check valve of the fluidly coupling facility  28  and seals to the outside circumference of the central nipple. This design results in a very cost effective and quick connect and disconnect mating system. The system has been designed to be one single turn for full connection. The seal that is formed is capable of withstanding very high pressures (300+psi) with very little operator effort for connecting and disconnecting. 
     The external threads  39  allow the operator to cap the device with an airtight seal for disposal or when not in use. The cartridge can be fabricated out of transparent material  42  and can include a plurality of gradient markings  44 , to aid in accurately dispensing a predetermined amount of the lubricant and/or fluorescent dye  32  therefrom. The lubricant canister  26  may further include a piston sealed therein. The piston may be made without any O-rings and uses pressure to further seal on the bore. 
     Furthermore, the design of the fluidly coupling facility  28  and the mating central nipple  33  ensures that only a minimal amount of fluid is left behind when the connection is disengaged. The fluorescent dye is very concentrated and expensive. In some applications, as little as two ml of fluid is injected per air conditioning or refrigeration system being tested so minimizing fluid loss is critical to the effectiveness of the diagnostic method. 
     The fluidly coupling facility  28 , as shown in FIGS. 1 and 6 through  11 , is a connector assembly  47  having a first end connected to the threaded nozzle  38  of the lubricant canister  26  and a second end connected to the service valve  34  of the pressurized system  24 . The connector assembly  47  consists of a flexible conduit  48 . A threaded fitting  50  is on the first end of the flexible conduit  48 , to engage with the threaded nozzle  38  of the lubricant canister  26 . A release valve  52  is on the second end of the flexible conduit  48 , to engage with the service valve  34  of the pressurized system  24 . 
     The connector assembly  47  further includes a one-way check valve  54  between the threaded fitting  50  and the first end of the flexible conduit  48 , which prevents any material from back flushing into and contaminating the lubricant and/or fluorescent dye  32  in the lubricant canister  26 . The release valve  52  contains a closeable control knob or valve  56 , which prevents any material from back flushing into the flexible conduit  48  from the service valve  34  of the pressurized system  24 , and allows the release valve  52  to disconnect from the service valve  34  of the pressurized system  24 , to prevent leakage of the lubricant and/or fluorescent dye  32  therefrom. 
     The release valve  52  in FIGS. 1,  6 ,  7  and  8 , includes a snap lock fitting  58  to engage with the service valve  34  of the pressurized system  24 . The release valve  52  in FIGS. 9,  10  and  11 , includes a threaded fitting  60 , to engage with the service valve  34  of the pressurized system  24 . 
     The lubricant forcing assemblage  30 , as shown in FIGS. 1 to  3  and  12  to  20 , is an injection device  62 . The injection device  62  contains a housing  64  having a receptacle portion  66 , to receive the lubricant canister  26  therein. A drive mechanism  68  forces the O-ring piston  40  into the tubular casing  36 , to cause the lubricant and/or fluorescent dye  32  to exit the threaded nozzle  38  through the fluidly coupling facility  28 , past the service valve  34  and into the pressurized system  24 . 
     The drive mechanism  68  in FIGS. 1 to  3  includes a hand grip  70  integral with and extending downwardly on the housing  64 . A trigger  72  is pivotally mounted to the housing  64  adjacent the hand grip  70 . A central drive shaft  74  extends longitudinally through the housing  64  and transversely past a pivotal portion of the trigger  72 . A cylindrical head  76  is on an inner end of the central drive shaft  74 , to engage with the O-ring piston  40  of the lubricant canister  26 . 
     A first pawl  78  is spring biased at  80  on the central drive shaft  74  forward the pivotal portion of the trigger  72 . A second pawl  82  is spring biased at  84  on the central drive shaft  74  rearward the pivotal portion of the trigger  72 . The second pawl  82  has a tongue  86  extending out through a rear wall of the housing  64  above the handgrip  70 . When the trigger  72  is squeezed the first pawl  78  will move into contact with the central drive shaft  74 , to push the central drive shaft  74  forward with the cylindrical head  76  making contact with the recessed O-ring piston  40 . The second pawl  82  prevents reverse movement of the central drive shaft  74 , until the tongue  86  is lifted up to disengage the second pawl  82 , allowing the central drive shaft  74  to be pulled back to a desired position. 
     The drive mechanism  68  in FIGS. 12 to  15  includes a hand grip  70  integral with and extending downwardly on the housing  64 . A trigger  72  is pivotally mounted to the housing  64  adjacent the handgrip  70 . A central drive shaft  74  extends longitudinally through the housing  64  and transversely above a pivotal portion of the trigger  72 . The central drive shaft  74  has a plurality of teeth  88  extending therealong. A cylindrical head  76  is on an inner end of the central drive shaft  74 , to engage with the O-ring piston  40  of the lubricant canister  26 . 
     A pawl  90  is pivotally mounted between the pivotal portion of the trigger  72  and the housing  64 . When the trigger  72  is squeezed, the pawl  90  will move into contact with the teeth  88  on the central drive shaft  74 , to push the central drive shaft  74  forward with the cylindrical head  76  making contact with the O-ring piston  40 . As best seen in FIGS. 13 and 14, the drive mechanism  68  can include a second pawl  92  spring biased in the housing  64  to make contact with the teeth  88  on the central drive shaft  74  forward the first pawl  90 , to prevent reverse movement of the central drive shaft  74 . 
     The drive mechanism  68  in FIGS. 16 to  19  includes a stationary nut  94  mounted vertically within a rear wall of the housing  64 . An elongated threaded rod  96  extends longitudinally through the stationary nut  94 . A cylindrical head  76  on an inner end of the elongated threaded rod  96  engages with the O-ring piston  40  of the lubricant canister  26 . A structure  98  on an outer end of the elongated threaded rod  96  is for rotating the elongated threaded rod  96  through the stationary nut  94  and moves the elongated threaded rod  96  with the cylindrical head  76  forward, to make contact with the O-ring piston  40 . 
     The rotating structure  98  in FIGS. 16 and 17 is a bolt head  100 , which can be turned by an open end or box wrench  102 . The rotating structure  98  in FIG. 18 is a socket head  104 , which can be turned by a ratchet socket wrench  106 . The rotating structure  98  in FIG. 19 is a handle rod  108  extending transversely through the outer end of the elongated threaded rod  96 , which can be turned by a hand of a person. 
     The drive mechanism  68 , shown in FIG. 20, includes a rear chamber  110  formed within the housing  64  and has an inlet port  112  to allow compressed gas to enter the rear chamber  110 . A central drive shaft  74  is carried longitudinally within the tubular casing  36  of the lubricant canister  26 . A cylindrical head  76  is on an inner end of the central drive shaft  74  to engage with the O-ring piston  40 . A transverse drive plate  114  is on an outer end of the central drive shaft  74  within the tubular casing  36  adjacent the rear chamber  10 . When the compressed gas is introduced through the inlet port  112  into the rear chamber  110 , the transverse drive plate  114  will push the central drive shaft  74  forward with the cylindrical head  76 , to make contact with the O-ring piston  40 . 
     Thus, the present invention provides for a device and method for injecting a small amount of a concentrated fluorescent additive or dye into the system, thereby making any leaks easier to find. The fluorescent dye can be injected into the system with the present device or they can be placed in the systems at the original equipment manufacturing facility prior to the system being put into service. These air conditioning and refrigeration systems are closed loop recirculating systems and the secondary fluid is a lubricant that also travels throughout the system while in operation. The dye will travel throughout the system and leak out with the refrigerant. The dye will leave a stain that can be further enhanced with the use of an ultraviolet (UV) lamp. The UV wavelength of light will excite the dye allowing the operator to more easily identify the exact location of the leak. The device can also be used to add the appropriate lubricant to the air conditioning or refrigeration system without stopping the system and without any special equipment. 
     Finally, a cartridge that is at or about atmospheric pressure while not in use contains the concentrated fluorescent dye and/or lubricant. The cartridge is connected to the device of the present invention in a way that will raise the pressure of the dye above that of the operating system. The connection between the device and the operating system must be airtight. The connection can be a quick coupler, thread or other means of positive, sealed connection. 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type describe above. 
     While certain novel features of this invention have been shown and described are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.