AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION INNOVATION PATENT "Improvements in Relation to Valves" The following statement is a full description of this invention, including the best method of performing it known to me: 2 IMPROVEMENTS IN RELATION TO VALVES 5 Background and Summary of the Invention This invention concerns fittings for use in refrigeration and air conditioning systems and in particular those valves with a rotalock connector for connection to the pipework of the refrigeration or air conditioning system. The name rotalock is a 10 generic term which identifies a particular configuration of connector. Rotalock connectors are well known in the industry so their construction and operation do not need to be described in detail in this specification. In the refrigeration and air conditioning industry the term "rotalock valve" is generally 15 understood to mean a valve having a rotalock connector at one inlet/outlet port on the side of the valve and a tubular port at the end of the valve. The tubular port is intended for brazing or soldering to the piping/tubing in a system. The rotalock connector provides the convenience of a multi-positional valve with a seal tight locking joint. The worldwide demand for rotalock valves has increased greatly in 20 recent years. They are a convenient and adaptable means for terminating and isolating refrigeration and air conditioning components and compressors. However, some major drawbacks with traditional rotalock valves have been: - they are notoriously inefficient in terms of flow capacity; 25 - they have steel connectors for brazing onto the copper refrigeration tube; - they have steel to steel seating and can require high torque to seat them properly; and - they have generally poor corrosion resistance and can lock the spindle due to corrosion. 30 An aim of the present invention is to provide a valve and a method of manufacturing a valve which address at least some of these difficulties, 3 In one aspect the invention provides a valve adapted for use in a refrigeration or air conditioning system, said valve comprising: - a valve body portion having a first port and a second port for flow of fluid 5 being controlled by the valve, said ports being aligned substantially at right angles to each other, and said first port having a rotalock connection associated therewith, and - a spindle threadedly engaged with the valve body portion such that: - when the spindle is rotated in a first direction an enlarged head on the 10 spindle is moved towards and into engagement with a valve seat associated with said second port, and - when the spindle is rotated in the opposite direction said enlarged head is withdrawn away from said valve seat until, when fully withdrawn, the enlarged head of the spindle is withdrawn sufficiently that it does not 15 restrict the flow path of the fluid between the two ports. In another aspect the invention provides a valve adapted for use in a refrigeration or air conditioning system, said valve comprising: - a valve body portion having a first port and a second port for flow of fluid 20 being controlled by the valve, said ports being aligned substantially at right angles to each other, said first port having a rotalock connection associated therewith for connecting the valve to said system, said second port having a tubular connector associated therewith and projecting from the valve body for soldered or brazed connection to said system, and 25 - a spindle threadedly engaged with the valve body portion such that: - when the spindle is rotated in a first direction an enlarged head on the spindle is moved towards and into engagement with a valve seat associated with said second port, and - when the spindle is rotated in the opposite direction said enlarged head is 30 withdrawn away from said valve seat, wherein said tubular connector is made of copper.
4 In another aspect the invention provides a method of manufacturing a valve constructed as described above, said method comprising brazing said tubular connector to the remainder of the valve body portion. 5 In a further aspect the invention provides a method of manufacturing a valve constructed as described above, said method comprising attaching the tubular connector to the valve body and thereafter electroplating said valve body portion while, during the electroplating operation, preventing electroplating of the tail portion 10 of the copper connector. Brief Description of the Drawings In order that the invention may be more fully understood there will now be described, 15 by way of example only, preferred embodiments and other elements of the invention with reference to the accompanying drawings where: Figure 1 is a view from one side of a valve according to a first embodiment of the invention; Figure 2 is an end view of the valve in Figure 1; 20 Figure 3 is a cross section view along plane A-A indicated in Figure 2; Figure 4 is an isometric view of a valve according to a second embodiment of the invention; Figure 5 is an end view of the valve in Figure 4; Figure 6 is a cross section view along plane B-B indicated in Figure 5 with the 25 valve in its fully closed position; and Figure 7 is a cross section view as in Figure 6 but with the valve in its fully open position. In Figures 4 to 7, components which are generally equivalent to components shown in 30 Figures 1 to 3 are identified by a number which is 100 greater than the corresponding components in Figures 1 to 3.
5 Description of Examples of the Invention and the Preferred Embodiment The valve 10 shown in Figures 1 to 3 is a rotalock valve according to a first embodiment of the invention. It is a spindle valve having a rotalock connector at one 5 of its entry/exit ports. The valve 10 comprises a valve body 12 into which is engaged a spindle 14. The spindle 14 has, on its inward end, an enlarged head 17 which moves within a main valve cavity 19 formed within the body 12, The valve body 12 has two main ports 20 10 and 22 which in use typically carry the flow of refrigerant working fluid being controlled by the valve 10. The first port 20 is on the side of the valve body 12 and the second port 22 is on the end of the valve 10. The spindle 14 has a male threaded portion 15 which engages with a corresponding is female threaded portion 16 in a neck portion 28 of the body 12. Rotation of the spindle therefore moves the head 17 of the spindle towards and away from the end port 22. A generally conventional gland nut 70 and gland packing 72 provides a seal between 20 the spindle 14 and valve body 12 outwards of the threaded portion 16. The valve 10 controls the flow of fluid which moves between the ports 20 and 22. The side port 20 is associated with a freely turning nut portion 30 of a rotalock connector. The nut portion 30 is held captive to the valve body in the normal manner 25 of such connectors. The end port 22 is aligned axially with the axis 36 of the spindle 14. As the spindle is rotated in a first direction, its head 17 is moved towards the end port 22 until the head 17 engages an internal lip 40 on the port 22. A tapered face 38 on the periphery of the 30 front 62 of the head 17 seats against the sealing lip 40 on the port 22 to close off flow of the fluid.
6 The second port 22 is formed by a short length of copper tube 52 which is brazed into the circular open end 56 of the main body portion. The tube 52 has an inwardly directed shoulder 54 towards its inner end which allows the tube to be partly inserted into the circular open end of the main body portion 24. The peripheral tapered face 5 38 on the steel head of the spindle bears against the inner edge 58 of the inner rim 60 of the copper tube. The harder steel bearing onto the softer copper allows a good seal from a relatively low torque applied to the spindle. It also greatly reduces the possibility of the head 17 sticking to its seat 58 through corrosion. 10 When the spindle 14 is withdrawn fully (as shown in Figure 3) in order to provide for maximum fluid flow through the valve, a tapered face 64 on the rear 66 of the head 17 seats onto a shoulder 68 on the body 12 behind the head 17. This provides a seal to prevent fluid loss through the clearance between the spindle and the neck portion of the body. 15 The main body portion 24 carries a pair of access ports 32 and 34 which are typically used for system charging and recovery, connection of pressure transducers and gauges, vessel positive pressurization by manufacturers for shipment to original equipment manufacturers, and charging oil into reservoirs under pressure. The access 20 ports 32 and 34 are aligned diametrically opposite each other but are offset from each other in the direction of the axis 36 of the spindle. The access ports 32 and 34 are threaded to suit a standard Schrader core. The distal end 42 of the spindle has a short section 43 with a square cross section 25 which permits a valve handle (not shown) to be engaged with the spindle to facilitate turning the spindle. As it is normally only during installation or maintenance that the spindle 14 needs to be moved from its usual position, the handle is commonly not left attached to the spindle and instead, a moulded plastic cap 18 is normally attached to the valve body 12 over the distal end 42 of the spindle to protect the valve from 30 inadvertent manipulation and to keep the spindle clean.
7 The cap 18 has a female thread 45 which engages with a male thread 46 on the valve body 12. When the cap 18 is screwed on tightly, a shoulder 48 on the valve body seats onto a tapered portion 50 of the cap. This provides a gas-tight seal which assists in preventing loss of working fluid which might exit the valve past the gland packing 5 between the spindle and the neck portion 28 of the body. When a valve 10 is being connected to external piping, a valve size is chosen to suit the size of copper piping/tubing being used. The outside diameter of the piping fits neatly into the tube 26. The installer inserts the pipe up to the shoulder 54, which 10 provides an appropriate stop, and heats the connection while applying a suitable soldering media and flux. The solder wicks readily into the small gap between the copper pipe and the copper tube 26 and this is much improved compared to a situation where the tube might be steel. 15 During manufacture of the valve 10, the main body portion 24 of the valve is formed from steel and the copper tube 26 is brazed into that body portion. The assembly is then electro-coated with a premium zinc CR3 "blue" plating, which provides superior corrosion protection to traditional electro-less nickel plating. While the assembly is being plated, a rubber boot is fitted over the end of the tube 26 so that the copper tube 20 is not coated externally or internally up to the shoulder 54. This facilitates much more efficient and effective soldering of the external piping to the tube 26. The valve 110 shown in Figures 4 to 7 has a body 112 comprising a steel spindle support portion 111 made of steel and a main flow portion 113 made entirely from 25 copper. The support portion carries the female thread 116 to engage the male thread 115 on the spindle 114. The spindle 114 has, on its inward end, an enlarged head 117 which moves within the main flow portion 113. The valve body 112 has two main ports, namely the side port 30 120 and the end port 122 which in use typically carry the flow of refrigerant working fluid being controlled by the valve 110. The side port 120 is associated with a freely turning nut portion 130 of a rotalock connector.
8 The valve seat 123 is made from a short brass ring brazed into the end port 122. The spindle 114 threadedly engages with the body 112 so that rotation of the spindle moves the head 117 of the spindle towards and away from the valve seat 123. 5 A gland nut 170 and gland packing 172 provides a seal between the spindle 114 and valve body 112 outwards of the threaded portion 116. The end port 122 is aligned axially with the axis 136 of the spindle 114. As the 10 spindle is rotated in a first direction, its head 117 is moved towards the end port 122 until the head 117 engages the valve seat 123. A tapered face 138 on the periphery of the front 162 of the head 117 seats against the sealing lip 140 on the valve seat 123 to close off flow of the fluid. 15 The steel face 138 bearing onto the softer brass valve seat 123 provides a good seal from a relatively low torque applied to the spindle. When compared to a steel spindle head seating onto a steel valve seat, it also reduces the possibility of the head 117 sticking to the seat 123 through corrosion. 20 When the spindle 114 is withdrawn fully (as shown in Figure 7) in order to provide for maximum fluid flow through the valve, a tapered face 164 on the rear 166 of the head 117 seats onto a shoulder 168 on the body 112 behind the head 117. This provides a seal to help prevent fluid loss through the gland packing 172. 25 It will be seen that for both valves 10 and 110, when the valve is fully opened the leading face 63, 163 of the head, is generally aligned with the portion of the wall of the respective side port 20, 120 which is furthest from the respective end port 22, 122. Thus the head of the spindle does not restrict the flow path of the fluid between the two ports. Prior art rotalock valves have not withdrawn the head of the spindle as far 30 as this from the valve seat and accordingly the fluid flowing through them has been hindered by the valve head.
9 During manufacture of the valve 110, the spindle support portion 11 is formed from steel and the main flow portion 113 is brazed onto it. The valve seat 123 is then brazed into the end port 122 and the whole assembly is then electro-coated with a premium zinc CR3 "blue" plating. While the assembly is being plated, a rubber boot 5 is fitted over the end of the tube at the end port 122 so that the copper port is not coated internally up to the valve seat 123. Brazing performance of the valve greatly improved when compared with existing designs. The tubular copper connector may be heated faster and more evenly than 10 traditional steel connector. It also allows the use of a lower silver content braising media which lowers the cost, there is less requirement for flux media and this produces better penetration of the braised joint leading to less leakage and stronger joint integrity. 15 Whilst the above description includes the preferred embodiments of the invention, it is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention. 20 It will be also understood that where the word "comprise", and variations such as "comprises" and "comprising", are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features. 25 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in Australia.