Abstract:
A device is disclosed for controlling the flow of refrigerant into a system and for controlling the application of a vacuum to evacuate the system via the same device prior to charging. The device is configured for controlling flow at the charging port to avoid loss of refrigerant from connecting lines. Piston operated valving internally mounted in a valve body controls the communication of refrigerant and vacuum sources to an outlet opening receiving a tubular charging port of the system to be charged. A pressure operated clamping piston actuates the gripping rings to secure the device to the charging port prior to both evacuation and charging and also acts to open the charging port valving as the fitting is clamped and sealed thereto. The outlet opening is defined by an end cap which is detachable from the fitting to allow use with different configuration charging ports by replacement with another end cap.

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns devices for use in dispensing fluid into a reservoir, such as in charging air conditioning systems with a refrigerant. 
     In charging auto air conditioning systems during production, a fitting is typically manually secured to a system charging port to enable the introduction therein of refrigerant received under pressure from a source connected to the fitting. 
     The air conditioning system is also typically evacuated prior to charging by being connected to a vacuum source for an interval just before charging. In such high volume auto production situations, a valving console is often employed which successively connects the fitting to vacuum and refrigerant sources, after the fitting has been manually secured to the charging port. 
     In such situations, the need for making the connection manually is burdensome and slows the operation. The use of a separate valving console results in the escape of refrigerant in the line connecting the console to the fitting, wasting this material and creating an environmental problem. The preciseness of the fill volume is also compromised by the loss of refrigerant in the connecting line. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a multifunction device having an end cap having a nozzle opening able to be received over a charging port and adapted to be fluid pressure clamped to the charging port. The clamping step also automatically opens a .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve associated with the charging port, and seals the nozzle opening to the charging port. 
     The device contains a pair of piston valves actuated by fluid pressure successively applied by a sequencing control to connect either an inlet port in communication with a vacuum source, or an inlet port communicating with a source of pressurized refrigerant, to a nozzle opening formed in an end cap of the fitting. 
     The valving pistons are movable in bores formed in a main valve body member and act in one porition thereof, assumed upon the application of .[.air.]. .Iadd.fluid .Iaddend.pressure, to place corresponding inlet ports in communication with the nozzle opening. 
     A clamping piston is mounted within the valve body to be movable in opposite directions upon the application of air presure supplied via internal passages on either side of the piston, and acts to cause gripping rings to move radially inward and at the same time brings an O-ring seal into contact with the open end, while also bringing an elongated element into contact with the .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve stem located within the charging port. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the device according to the present invention. 
     FIG. 2 is an upper end view of the device shown in FIG. 1, showing the various inlet ports, together with a schematic depiction of the system connections thereto. 
     FIG. 3 is an exploded perspective view of the components of the device shown in FIG. 1. 
     FIG. 4 is a view of the longitudinal section 4--4 taken in FIG. 2. 
     FIG. 5 is a fragmentary view of section 5--5 taken in FIG. 2. 
     FIG. 6 is a fragmentary view of the section 6--6 taken in FIG. 2. 
     FIG. 7 is an enlarged sectional view of the end cap of the device shown in FIG. 1 .[.showing the mating engagement with an inlet charging tube of a system to be charged.].. 
     FIG. 8 is a view of the transverse section 8--8 taken through the device shown in FIG. 4. 
     FIG. 9 is an exploded perspective view of the end of the main valve body and an alternately configured end cap and associated components attachable thereto. 
    
    
     DETAILED DESCRIPTION 
     In the following description, a particular embodiment is described in accordance with the requirements of 35 USC 112, and specific terminology employed for the sake of clarity, but it is to be understood that the same is not intended to be limiting, inasmuch as the invention is capable of taking many forms within the scope of the appended claims. 
     Referring to the drawings, the multifunction device 10 according to the present invention is comprised of a valve body assembly 12 including a generally elongate main valve body member 14 having an inlet porting cap 16 affixed at one end by capscrews 11 and an end cap 18 affixed at the other end. 
     The device 10 is sized to be manually grasped as at central knurled area 15, to be placed on a charging port, comprised of an inlet tube .[.20.]. connected to the system to be charged. A .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve is typically employed, having a valve stem .[.22.]. which when pushed controls opening of the valve in the manner well known to those skilled in the art. 
     The inlet porting cap 16 carries three pairs of line connector fittings, &#34;on-off&#34; clamping air pressure connector fittings 24, 26, vacuum &#34;on&#34; air pressure connector fittings 28, refrigerant &#34;on&#34; air pressure connector fitting 30, vacuum source connector fitting 32, and refrigerant connector fitting 34. 
     FIG. 2 illustrates the corresponding ports 24A-34A formed in porting cap 16, and schematic of the remaining fluid circuit. 
     Fluid lines (not shown) are connected to each connector fitting 24-34. Port 24A is connected to a two-way valve 36 which in turn connects port 24A either to a source of air pressure 38 or to a vent as shown, and port 26A is connected to a two-way valve 40, connecting port 26A to a pressure source 42 or vent. 
     Similarly, port 38A is connected to a two-way valve 44 which in turn connects port 28A either to pressure source 38 or vent, and port 30A is connected to a two-way valve 46 which in turn connects port 30A to pressure shource 42 or vent. 
     The operation of the two-way valves 36, 40, 44, 46, is by solenoids (not indicated) under the control of the sequencing control circuit indicated at 48. 
     Port 32A is directly connected to a source of vacuum 50 while port 34A is connected to a source of pressurized refrigerant 52. 
     Valving means is provided to provide selective control over communication between each port 32A and 34A and an outlet in the end cap assembly 18 (FIG. 4), with actuation by means of air pressure introduced at ports 28A and 30A. 
     The valving means includes a pair of valving pistons 56, 58 slidably fit within bore 60, 62 respectively formed in the main valve body member 14 while O-rings 71, 73 seal each bore 72 and 74 against the escape of air pressure through the interface of porting cap 16 and main valve body member 14. O-ring seals 64, 66 and 68, 70 create fluid tight chambers 72, 74 above each piston 56, 58 respectively while O-rings 71, 73 seal each bore 72 and 74 against the escape of air pressure through the interface of porting cap 16 and main valve body member 14. Recesses 76, 68 are formed into the top of each piston to ensure application of air pressure introduced into chamber 72 or 74 via ports 28A and 30A is exerted on an appreciable area of each piston 56, 58. 
     Each piston 56 and 58 is formed with a hollow 80, 82 in the lower end receiving a compression spring 84, 86 respectively each of which urge the associated spring upwardly in opposition to fluid pressure in chamber 72 or 74. 
     When either piston 56 or 58 is in the down position, ports 88 or 90 extending about the skirt of piston 56 or 58 respectively and into hollows 80, 82 thereof respectively, are brought into alignment with annular groove 92, 94 and when in the normal up position grooves 92 or 94 are blocked by the outside of piston 56 or 58. 
     Groove 92 and 94 are in turn continuously pressurized during operation of the apparatus via ports 32A, 34A with a vacuum and pressurized refrigerant respectively. FIG. 8 shows that this is accomplished by internal passsages 96 and 98 extending length wise from ports 32A and 34A alongside bores respectively, intersection cross passages 100, 102 respectively. The outside section may be plugged after drilling as by welding as shown. O-ring seals 104, 106, 108 and 110 prevent leakages to or from grooves 92, 94 respectively. 
     Vacuum or pressurized refrigerant is applied via central bore 112, and thence through a bore 114 extending through a clamping piston 116; past openings 118 in a .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve operating member 120; through a clearance between a rod element 122 of member 120 and a smaller diameter bore 124 in piston 116; and through an internal cavity 126 of piston 116 to outlet nozzle opening 54. 
     End cap 18 is comprised of a nose piece 128 secured by capscrews 130 to an intermediate sleeve 132, in turn secured with capscrews 133 to the end face of main valve body member 14. 
     Clamping piston 116 is formed with a first reduced diameter end 136 piloted in bore 138 of main valve body member 114, and a second reduced diameter end 140 piloted in a bore 142 formed in intermediate sleeve 132. 
     An intermediate larger diameter piston portion 144 is received in bore 146 to define upper and lower chambers 148 and 150, isolated from each other by O-ring 152 carried by piston portion 144, and sealed with O-rings 154 and 156. 
     Air pressure is supplied to either chamber 148 or 150 by internal passages 158 and 160 extending from ports 24A and 26A respectively (FIGS. 5 and 6) through main valve body member 14, and internal passages 162 and 164 in intermediate sleeve 132. O-ring 166, 168, 170, 172 seal the passages 158, 160 at the interface of porting plac 16 and main valve body member 14, and intermediate sleeve 132. Clamping piston 116 thus is forced either up or down by the application of air pressure at port 24A or 26A. 
     Clamping piston 116 is formed with a pair of opposed curved blades or tangs 174 extending into corresponding peripheral recesses 176 formed in a sleeve 178 defining nozzle outlet 54, sleeve 178 pressed into bore 180 of nos piece 128. Sleeve 178 carries a pair of gripping rings 182 received in circumferential opposed slots 184 machined into sleeve 178. 
     FIG. 7 illustrates that as clamping piston 116 descends, tangs 174 cam the gripping rings 182 radially inward towards the inlet the .[.20.]. inserted into opening 54. .[.A groove 186.]. .Iadd.An annular feature of the inlet tube .Iaddend.therein is aligned with the gripping rings 182, so that a clamping action occurs by the rings 182 moving into the .[.groove 186 .Iadd.annular feature.Iaddend.. 
     A retainer ring 188 is pressed into cavity 16 of clamping piston 116 bringing O-ring 190 aligned with chamber opening 192. 
     Thus, inlet tube .[.20.]. is sealed by movement of the clamping piston 116 bringing O-ring 190 against the end face .[.194.]. thereof. 
     Simultaneously, rod element 122 is moved against .Iadd.the .Iaddend.valve .Iadd.of the Schrader type valve, .Iaddend.stem .[.22.]. to open the .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve (not shown) establishing communication between the vacuum port 24A or refrigerant port 26A and the system to be charged. 
     A spring 196 and annular retainer 198 act to urge the member 120 outward, allowing some .[.last.]. .Iadd.lost .Iaddend.motion as the .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve is fully opened and the piston 116 moves to the full down position. 
     Thus, the operator need only position the device 10 over the inlet tube .[.20.]., with clamping, sealing and opening of the .[.Schroeder.]. .Iadd.Schrader type .Iaddend.valve completed by the application of clampng air pressure. 
     The application of vacuum and then refrigerant is accomplished by the same fitting by application of air pressure to piston 58 and thereafter piston 60. The valving of the refrigerant is at the point of charging to eliminate the loss of refrigerant and the imprecision resulting from the use of long connecting lines. 
     Disconnect is also simply achieved by the application of air pressure to move piston 116 upward, after both vacuum and refrigerant ports are sealed by movement of pistons 58 and 60 upward, as viewed in FIG. 4, by the release of air pressure in chambers 72 and 74. 
     The end cap 18 is detachable so as to be repalced with end caps of differing configurations, as to be fit to different size valves, and for different installations. Such an end cap 18A is shown in FIG. 9, extended in length so as to facilitate reaching relative inaccessible inlet tubes .[.20.].. In this case a longer length nose piece 128A is employed as well as .[.a.]. .Iadd.an .Iaddend.extended length clamping piston 116A, necessitating a .[.space.]. .Iadd.spacer .Iaddend.tube 200 to reach member 120. This is mated to the remaining components without any modification to enable use of the same fitting 10 for various requirments. 
     Many variations of the specific arrangement are of course possible.