Abstract:
A tool assembly for connection to a charging inlet tube of a fluid receiving system, and for evacuating and dispensing a charging fluid to the fluid receiving system. The tool assembly includes a tool housing having an upper and a lower housing half and including a plurality of internal valve components. The internal valve components are assembled in sliding engagement with each other within the tool housing and are held in assembled engagement by assembly of the upper and lower housing halves together whereby the tool assembly may be quickly disassembled and assembled for replacement of components. Fluid flow through the tool assembly is directed by an inner body positioned between the upper and lower housing halves, and vacuum and fluid charging is controlled by a vacuum control poppet and fluid control poppet, respectively, which poppets are longitudinally moveable relative to the inner body and to each other. The fluid is discharged from the tool assembly at a charge gate, and a stem member extends through the charge gate for actuating a valve within the inlet tube. The stem member directly engages the charge gate in order to provide for accurate control of the travel distance of the stem member.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to devices for use in dispensing fluids to a fluid system and, more particularly, to a device for evacuating and dispensing a fluid to a system, such as a charging fluid to a refrigeration or air conditioning system. 
     2. Related Prior Art 
     In motor vehicle production lines, the vehicle air conditioning system is typically evacuated and filled at a charging port of the system. In order to facilitate the charging of the system, a tool is provided which is moved into engagement with the port and which opens a Schrader valve on the port. The port is alternately subjected to vacuum to substantially eliminate air from the system and subjected to a pressurized charging fluid for filling the system with a refrigerant. 
     It should be noted that in prior art tools, multiple parts forming the internal valve elements for the tool are stacked together and are held in position by bolts extending between the various valve elements, including bolts extending both in the axial and radial direction relative to the axis of the tool. This can lead to a time consuming overhaul process which can be undesirable in mass production assembly lines. In addition, such prior art tools include an element for actuating a Schrader valve wherein the actuating element is limited in movement toward the Schrader valve. However, the stop for the actuating element is often located on an internal valve element which is displaced from the Schrader valve by several other valve members, i.e., by the multiple parts forming the stacked internal valve elements, such that the combined tolerances of these members can result in a wide variation of travel for the actuating element between different tools. This can have a detrimental effect on the operation of the tool in that the actuating element may in some cases be overextended, resulting in damage to the Schrader valve, or in other cases, the actuating element will not extend to the point of fully opening the Schrader valve and thus limit the flow capacity through the tool. 
     It is generally desirable in a high volume vehicle production line to provide a fitting which may be quickly attached to the port by an automatic mechanism, and which will also evacuate and fill the system to be charged at a high rate. Accordingly, it is desirable to have a dispensing tool which is of simple and reliable construction in order to insure repeated performance on successive vehicles while minimizing maintenance on the tool. Further, it is desirable to provide a tool which provides for high vacuum and charging fluid flow rates through the tool in order to minimize the amount of time that the tool must remain attached to the vehicle. It is also desirable to have a tool which is easily disassembled and assembled by maintenance workers responsible for maintaining operation of the tool. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a tool assembly is provided for dispensing fluid to a fluid receiving system having a charging inlet tube, and typically including a Schrader valve for controlling flow of fluids into and out of the fluid receiving system. The tool assembly includes a tool housing having an upper housing half and a lower housing half, and enclosing a plurality of internal valve elements. 
     The lower housing half includes a lower end, and a clamp assembly is located at the lower end including radially moveable clamp members for coupling the tool assembly to a charging inlet tube for a fluid receiving system. The upper housing half includes an upper end defining a plurality of openings for selectively admitting fluids to an interior portion of the housing, and the plurality of valve elements are assembled in axially slidable engagement with each other within the upper and lower housing halves for controlling flow of fluids through the interior portion of the housing. 
     In accordance with one aspect of the invention, the upper and lower halves are connected to each other at connector portions of the upper and lower housing halves wherein engagement of the connector portions with each other closes the housing to maintain each of the valve elements in operable relation to other ones of the valve elements. 
     One of the plurality of valve elements comprises an inner body located in stationary relationship relative to the upper and lower housing halves, and the inner body includes passages for controlling flow of vacuum and a charging fluid, which fluid flows are provided to the assembly through the openings in the upper end of the upper housing half. The inner body defines a cavity for receiving a fluid control poppet, and the fluid control poppet includes a hollow cylindrical portion receiving a cylindrical portion of a vacuum control poppet therein. The fluid control poppet and vacuum control poppet are supported for longitudinal movement in an axial direction relative to the inner body and relative to each other for controlling flow of vacuum and flow of charging fluid through the tool assembly. 
     The inner body additionally defines a vacuum control air passage for controlling air to an area between the fluid control poppet and vacuum control poppet whereby the vacuum control poppet is actuated for movement to open a vacuum passage to the charging inlet tube. 
     In one embodiment of the invention, the clamp assembly includes a clamp cylinder having a plurality of radially extending apertures wherein each aperture in the clamp cylinder includes a piston which is radially moveable for biasing respective clamp balls radially inwardly into engagement with the charging inlet tube in order to clamp the assembly to the charging inlet tube. The clamp balls are supported in a charge gate cylinder which is positioned within the clamp assembly. The charge gate cylinder comprises an upper cavity and a lower cavity and a charge gate located between the upper and lower cavities and defining a passage for fluid between the tool housing and the charging inlet tube. 
     An elongated stem member is supported for longitudinal movement through the tool housing and includes an upper portion and a lower portion. The stem member extends through the vacuum control poppet, and the lower portion of the stem member extends through the charge gate for engagement with a Schrader valve. The stem member includes s shoulder adjacent to the lower portion for engaging against the charge gate for limiting movement of the stem member in a direction from the upper housing half toward the lower housing half. The stem member is actuated for movement by air pressure provided at a stem port located centrally of the upper housing half and applying air pressure to the upper portion of the stem member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of the tool assembly of the present invention; 
     FIG. 2 is a top perspective view of the tool assembly; 
     FIG. 3 is a top perspective view of the inner body of the tool assembly; 
     FIG. 4 is a bottom perspective view of the inner body of the tool assembly; 
     FIG. 5 is a perspective view of the charge gate assembly; 
     FIG. 6 is a top perspective view of the charge gate cylinder; 
     FIG. 7 is a bottom perspective view of the charge gate cylinder; 
     FIG. 8 is a cross sectional view taken along line A—A in FIG. 2 showing the tool assembly in an unclamped position; 
     FIG. 9 is a cross sectional view taken along line B—B in FIG. 2 showing the tool assembly in a clamped position; 
     FIG. 10 is a cross sectional view taken along line C—C in FIG. 2 showing the clamp signal flag; 
     FIG. 11 is a cross sectional view taken along line A—A in FIG. 2 showing the stem member of the tool assembly in an actuated position; 
     FIG. 12 is a cross sectional view taken along line B—B in FIG. 2 showing actuation of the vacuum control poppet; 
     FIG. 13 is a cross sectional view taken along line A—A in FIG. 2 showing actuation of vacuum to remove air from a fluid receiving system; and 
     FIG. 14 is a cross sectional view taken along line A—A showing actuation of a charging fluid and movement of a fluid control poppet to provide the charging fluid to a receiving system. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, the tool assembly of the present invention includes a tool housing  10  comprising an upper housing half  12  and a lower housing half  14 . The upper housing half  12  includes an upper connector portion  16 , and the lower housing half  14  includes a lower connector portion  18  wherein the upper and lower connector portions  16 ,  18  of the illustrated embodiment comprises threaded portions for cooperating with each other whereby the cooperation of the threaded connector portions  16 ,  18  forms a fully enclosed housing  10  as will be discussed further below. 
     A charge gate assembly  20  is positioned within the lower housing half  14  and includes a lower end  22  located adjacent a lower end  24  of the lower housing half  14 . The charge gate assembly includes a clamp assembly  26  and a charge gate cylinder  28  extending within the clamp assembly  26 . 
     An inner body  30  is located above the charge gate assembly  20  and includes a lower extension  32  extending into an upper cavity  34  (FIGS. 5 and 6) of the charge gate assembly  20 . The inner body  30  includes an interior cavity  36  (FIG. 3) receiving a fluid control poppet  38  and a vacuum control poppet  40  therein. A stem member  42  is provided extending through the vacuum control poppet  40  and passing to a location adjacent the lower end  22  of the charge gate assembly  20 , and includes an upper portion  44  and a lower portion  46  wherein the lower portion  46  includes an end  48  for engaging and actuating a Schrader valve on a charging inlet tube for a fluid receiving system. An enlarged upper end  50  of the stem member  42  extends into a stem port  52  which is positioned through a central opening of the upper housing half  12 . 
     A spring  54  is provided extending between a flange  56  on the stem port  52  and the vacuum control poppet  40  for biasing the vacuum control poppet downwardly toward the inner body  30 . Further, a spring  58  is provided engaging a lower surface of the enlarged head  50  of the stem member  42  and engaging the vacuum control poppet  40  for biasing the stem member  42  in a direction toward an upper end  60  of the upper housing half  12 . 
     It should be noted that the charge gate assembly  20 , inner body  30 , fluid control poppet  38 , vacuum control poppet  40  and stem member  42  all comprise internal valve elements, and that these internal valve elements are assembled in sliding engagement with each other. In order to facilitate alignment in a circumferential direction, an alignment dowel pin  62  is located between the clampe assembly  26  and the charge gate cylinder  28 , an alignment dowel pin  64  is located between the charge gate assembly  20  and the inner body  30 , and an alignment dowel pin  66  is located between the inner body  30  and an interior surface of the upper end  60  of the upper housing half  12 . The alignment dowel pins  62 ,  64 ,  66  insure alignment of fluid passages through the internal valve elements while permitting slidable assembly of the internal valve elements. 
     Referring to FIG. 8, the tool assembly  10  is illustrated in an unclamped position wherein the tool assembly is illustrated located over a charging inlet tube  11  having a circumferential fitting groove  13  formed adjacent an end  15  thereof. The end  15  of the inlet tube  11  is located within a lower cavity  68  of the charge gate cylinder  28  below a charge gate  70  (see also FIG. 7) and in engagement with a resilient sealing member  72 . In the position illustrated, a plurality of clamp balls  74 , supported within radially extending apertures formed in the charge gate cylinder  28 , are located adjacent to, but not engaged in, the groove  13 . 
     Referring to FIG. 9, the tool assembly  10  is clamped to the inlet tube  11  by means of air actuation wherein an air pressure acts upon a plurality of pistons  76  supported for radial movement within apertures  77  (FIG. 1) formed in the clamp assembly  26  which are aligned with and act upon respective clamp balls  74  to push the balls  74  into engagement with the groove  13 . The air pressure for actuating the cylinders  76  is provided by a clamp control air passage extending from the upper housing half  12  to the pistons  76 , as illustrated by heavy stipling. Specifically, the upper end  60  of the upper housing half  12  is provided with a clamp control air port  78  (FIG. 2) which is aligned with a clamp control air passage  80  formed in the inner body  30  (see also FIGS.  3  and  4 ). An outlet of the clamp control air passage  80  at the bottom of the inner body  30  is aligned with a clamp control air passage  82  formed in the charge gate cylinder  28 , and the passage  82  opens into a gap  84  formed between adjacent surfaces of the charge gate cylinder  28  and the clamp assembly  26 . The gap  84  is in fluid communication with a gap  86  defined between an outer surface  88  of the clamp assembly  26  (FIG. 5) and an inner surface of the lower housing half  14 . The gap  86  is in fluid communication with the apertures  77  containing the pistons  76 . 
     Referring to FIG. 10, it should be noted that an additional clamp control air passage is provided extending from the area of the gap  84  up to a signal flag  90  at the upper end  60  of the upper housing half  12 . The additional clamp control air passage comprises a passage  80 ′ formed in the inner body  30  and a passage  82 ′ formed in the charge gate cylinder  28  wherein the passages  80 ′ and  82 ′ are substantially identical to the passages  80  and  82  for providing pressurized air from the port  78 . The passages  80 ′,  82 ′ convey air to the signal flag  90  whereby air acting on a lower piston end  92  of the signal flag  90 , causes the signal flag  90  to extend from the upper end  60  of the upper housing half  12  and thereby indicate that the clamp assembly  26  has been actuated to clamp onto the inlet tube  11 . The signal flag  90  further includes a spring  94  acting against a cover plate  95  to bias the signal flag back into the upper housing half  12  when the clamp control air is deactivated. 
     Referring to FIG. 11, the stem member  42  is actuated in longitudinal movement downwardly by application of stem member actuation air (illustrated by heavy stipling) to an opening  96  at an upper end of the stem port  52  wherein the stem member  42  is caused to move against the biasing force of the spring  58  and moves from the position shown in FIG. 9 to that shown in FIG.  11 . Actuation of the stem member  42  causes the end  48  thereof to move into engagement with a Schrader valve element  49  in order to open the Schrader valve located in the inlet tube  11 . 
     The stem member  42  is formed with a shoulder portion  98  which extends radially outwardly from a diameter of the lower portion  46  of the stem member  42 . The shoulder portion  98  engages against an upper surface area  100  of the charge gate  70  to thereby limit movement of the stem member  42  toward the Schrader valve of the inlet tube  11 . It should be noted that the travel of the stem member  42  is capable of being highly accurately controlled by controlled machining of the distance between the shoulder portion  98  and the end  48  of the stem member  42 . Further, it should be noted that this controlled tolerance is provided in combination with engagement of the shoulder portion  98  on the same component as is used to position the tool assembly relative to the inlet tube  11 , i.e., the charge gate cylinder  28 . Thus, accurate control of the travel distance of the stem member  42  is provided to accurately control opening of the Schrader valve in the inlet tube  11  and thereby both avoid over-actuation and possible damage of the Schrader valve, while also insuring full opening of the Schrader valve. 
     Referring to FIG. 12, a vacuum control air passage extends from a port  102  (see also FIG. 2) in the upper end  60  of the upper housing half  12  to a passage  104  formed in the inner body  30 . The passage  104  extends to the interior cavity  36  of the inner body  30  at a location between a radially extending flange  106  of the fluid control poppet  38  and a radially extending flange  108  of the vacuum control poppet  40 . When air pressure is applied to the port  102  (as illustrated by heavy stipling), it causes the vacuum control poppet  40  to move upwardly into engagement with a pair of spacing tabs  110  (see FIG. 1) located on the bottom of the stem port  52 , against the biasing force of the spring  54 . 
     It should be noted that upward movement of the vacuum control poppet  40  causes a cylindrical body  114  of the vacuum control poppet  40  to move relative to a cylindrical body  112  of the fluid control poppet  38  whereby a seal  116  at a lower end of the cylindrical body  114  moves out of engagement with a lower end  118  of the cylindrical body  112  to thereby open a passage to the charge gate  70  from a cavity  120  located between the cylindrical bodies  112 ,  114 . 
     Referring further to FIG. 13, the cavity  120  between the cylindrical bodies  112 ,  114  is connected to a vacuum port  122  at the upper end  60  of the upper housing half  12  through a plurality of radially extending apertures  124  formed in the cylindrical body  114 . In addition, the vacuum is communicated through a gap  126  formed between a reduced portion  128  of the stem member  42  and the interior of the cylindrical body  114 , and passes through an area above the flange  108  in the interior cavity  36  of the inner body  30 , and connected to the port  122  through a vacuum passage  130  formed in the inner body  30  (see also FIG.  3 ). It should be understood that the spacing tabs  110  permit fluid communication between the inner and outer portions of the stem port  52  across the upper surface of the flange  108 . Further, it should be noted that fluid flow through the charge gate  70  is provided at arcuate portions  132  (see FIGS. 6 and 7) forming openings around the surface area  100  of the charge gate engaged by the shoulder portion  98  of the stem member  42 . 
     After vacuum is applied to the port  122  for a predetermined amount of time, whereby a fluid receiving system associated with the inlet tube  11  is evacuated, the vacuum control air pressure applied to port  102  is deactivated whereby the spring  54  will cause the vacuum control poppet  40  to return downwardly for engagement of the seal  116  with the end  118  of the cylindrical body  112 . 
     Referring to FIG. 14, a charging fluid (illustrated by heavy stipling) is provided to the evacuated fluid receiving system through a fluid fill port  134  which is connected to a fluid fill passage  136  defined in the inner body  30  (see also FIGS.  3  and  4 ). The charging fluid is fed to a first cavity area  138  formed between a surface  140  of the inner body and an interior surface of the lower housing half  14 , and subsequently enters a second cavity area  142  located between a surface  144  of the inner body  30  and an upper surface of the charge gate cylinder  28 . The charging fluid then flows to a third, annular cavity area  146  extending around a portion of the lower extension  32  of the inner body adjacent an inner surface of the charge gate cylinder  28 . From the annular cavity area  146 , the charging fluid passes through a plurality of apertures  148  formed in the lower extension  32  of the inner body  30  to an annular cavity  150  between the cylindrical body  112  of the fluid control poppet  38  and the lower extension  32  of the inner body  30 . The pressure of the charging fluid acts on the end  118  of the fluid control poppet  38  to cause the fluid control poppet  38  to move upwardly out of sealing engagement with a charge gate seal  152  against the biasing force of the spring  54 . 
     The charging fluid will flow through the arcuate open areas  132  of the charge gate  70  until the fluid pressure applied at the port  134  is deactivated. At this time, the spring  54  will act through the vacuum control poppet  40  to bias the fluid control poppet  38  downwardly back into engagement with the charge gate seal  152 . The charging operation is completed by deactivating the pressure to the stem member  42  through the stem port  52  and deactivating the clamp control air applied at port  78  whereby the activation of the Shrader valve and clamping applied at the inlet tube  11  is released to permit the tool assembly  10  to be moved out of engagement with the fluid receiving system. 
     It should be noted that, although not specifically referenced, O-rings are provided in a conventional manner to provide sealing between the internal valve components in order to insure fluid flow along the described paths. 
     Further, from the above description, it should be apparent that connection between the housing halves  12 ,  14  causes the internal valve components to be sealingly compressed together in sliding engagement with each other without requiring connecting fasteners between the components. It should also be apparent that the connection between the upper and lower housing halves  12 ,  14  may be performed by a simple twisting operation causing relative movement between the two housing halves  12 ,  14  to quickly engage and disengage the housing halves to each other. Also, a locking ring  154  may optionally be provided to resist disengagement of the housing halves  12 ,  14 . Further, other engagement structures may be incorporated, other than a threaded connection, whereby the relative movement of the housing halves  12 ,  14  results in a positive engagement between the housing halves for containing the internal valve components. 
     While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.