Patent Application
20190338992
The present invention relates generally to the field of pressurized fluid systems, and more specifically relates to an apparatus for injecting an amount of additive into a pressurized air conditioning or refrigeration system, for example for detecting and sealing leaks. The additive can be one or a combination of a fluorescent dye, a lubricant, a leak stop, a performance enhancer, an anti-moisture additive, a de-icing additive, an acid neutralizing additive, or an internal refrigerant leak detector.
Apparatus for injecting a predetermined amount of a fluorescent dye and/or lubricant into a pressurized system have already been proposed. These apparatus normally comprise a cartridge containing the dye to be injected in the system and having an outlet nozzle, a sealing piston slidable inserted in the cartridge to force the dye out the outlet nozzle, and a hose assembly having an end to be connected to the outlet nozzle and the other end suitable to be connected to a service valve of the pressurized air conditioning or refrigeration system. In one embodiment, known for example from U.S. Pat. No. 6,164,348, the hose assembly comprises a pipe thread to a Luer coupling thread adapter, having one end adapted to be mated with a Luer coupling of the outlet nozzle of cartridge; the other end of the adapter is threaded to a check valve fitting, preventing back flow to the syringe. The check valve fitting is in turn threaded to a hose end fitting connected to one end of a flexible high pressure hose segment. A SCHRADER valve coupling is connected to the other end of the hose segment, adapted to be threadably connected to a SCHRADER valve of the low pressure side of an air conditioning/refrigeration system compressor. A check valve is interposed between the cartridge and the hose assembly.
It is evident that such an arrangement requires the provision and the assembly of a number of components and therefore has a complicated structure, also expensive to manufacture and store for the supplier. This is a great drawback also because the market requires that the apparatus is entirely disposable.
Apparently, the length and volume of the hose is approximately the same of the cartridge. This is because in view of the above construction the hose segment must be able to withstand high pressure for safety reasons. In addition, the presence of many components, and in particular of the bulky hose segment, may cause the formation of air in the hose assembly. The user must pay attention to push out the air from the hose assembly to prevent that bubbles of air are dangerously injected into the system with the dye.
Another disadvantage of this arrangement is that, when the piston has forced all the dye out the cartridge, a large quantity of the dye remains contained in the hose assembly.
Another disadvantage of this arrangement is that it cannot be used in narrow spaces. In fact, in view of the fact that the hose of the hose assembly is a high pressure hose, it has a limited flexibility and is prone to kink if forced beyond this limit.
It is the object of the present invention to provide an apparatus for injecting an additive in an air conditioning or refrigeration system which is able to overcome the above cited drawbacks of the prior art devices.
A further object is to provide an apparatus for injecting an additive 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 injecting an additive in a pressurized air conditioning or refrigeration system that is economical in cost to manufacture.
A still further object is to provide an apparatus for injecting an additive in a pressurized air conditioning or refrigeration system that can be used also in narrow spaces.
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
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:
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views,
The apparatus 10 for injecting an additive in a pressurized air conditioning or refrigeration system comprises a cartridge 12. An adapter 20; 200 is for fluidly coupling the cartridge 12 to a service valve 30; 300 of the pressurized system 5; 5′. Moreover, a bending unit 100 interposed between the cartridge 12 and the adapter 20; 200 allows to inject the additive in the pressurized air conditioning or refrigeration system irrespective of the reciprocal orientation of the cartridge 12 and the adapter 20; 200.
The cartridge 12 defines an axis X and includes a tubular casing 14 for holding an additive to be injected in the pressurized air conditioning or refrigeration system. A threaded nozzle 16 is integral with and extends out from a first end of the tubular casing 14, to engage with one end of the bending unit 100. A sealing piston 40 is inserted within an open second end of the tubular casing 14 and is slidable within the tubular casing 14 to force the additive out the threaded nozzle 16.
The tubular casing 14 can be fabricated out of transparent material and can include a plurality of gradient markings, to aid in accurately dispensing a suitable amount of the additive therefrom.
In one embodiment, the cartridge 12 further includes a threaded cap—not shown—to engage with the threaded nozzle 16 when the cartridge 12 is not in use, so as to prevent leakage of the additive through the threaded nozzle 16.
In one embodiment, the cartridge 12 may be disposable, e.g. in the form of a disposable syringe of the kind commercially available, at low cost, being constructed of a molded plastic.
In one preferred embodiment, the additive will be prepackaged by the supplier of the additive in the cartridge. The cartridge 12 preferably has a volume of 6 ml, which will allow for one sufficient volume to leak test a typical automotive air conditioning system, or, for one injection of dye into a building air conditioning system.
In one preferred embodiment, the threaded nozzle 16 comprises an outlet tube 16′ communicating with the interior space of the cartridge. The tube 16′ is surrounded with a “Luer” coupling 16″ which comprises an internal thread of a form which creates a tight seal with an element advanced thereinto.
The adapter 20; 200 is in the form of a fitting having a fitting body defining an axis Y and having a first end portion 20; 200′ and a second end portion 20″; 200″ connected to the service valve 30; 300 of the pressurized system 5, 5′. The first end portion 20′, 200′ has an outer thread and an inner frusto-conical portion 21′; 210′.
In a preferred embodiment, the second end portion 20″; 200″ of the fitting body forms a SCHRADER valve coupling to be connected to a SCHRADER valve of the service valve 30; 300 of the pressurized air conditioning or refrigeration system 5; 5′.
In one embodiment (
In one alternative embodiment (
In a preferred embodiment, a check valve 50 is housed in the fitting body of the adapter 20; 200, between the first end portion and the second end portion, in order to prevent back flow of the fluid from the air conditioning or refrigeration system to the cartridge and to the bending unit. For example, the check valve is a ball check valve. In this manner, it is possible to connect the apparatus 10 to the pressurized air conditioning or refrigeration system without the danger of bursting of the bending unit.
In a preferred embodiment, the adapter 20; 200 is disposable, e.g. constructed of a molded plastic, for example Nylon.
In a preferred embodiment, the adapter 20; 200 is fabricated out of transparent material and a sealing ring 52 contained in the second end portion and/or the ball of the check valve 50 can have different colors for identifying the different sizes of the second end portion 20″; 200″.
The bending unit 100 consists of a central flexible capillary tube 110 and two end fittings 120, 130. In order to allow to inject the additive in the pressurized air conditioning or refrigeration system irrespective of the reciprocal orientation of the cartridge 12 and the adapter 20; 200, the flexible capillary tube 110 is adapted to pass from an unbent state in which axes X and Y are coincident to each other (
To this end, the flexible capillary tube 110 must be sufficiently flexible without incurring kinking. Suitably, the flexible capillary tube 110 is adapted to be bent at least at 90° without kinking. Advantageously, the flexible capillary tube 110 is made of an elastomer, e.g. polyurethane, and has a Shore A hardness of at least 80, e.g. 95.
Suitably, the flexible capillary tube 110 has a very low internal volume. For example, the flexible capillary tube 110 has a length of 35 mm, an internal diameter of 2 mm and an outer diameter of 4 mm, i.e. a wall thickness of 1 mm.
In a preferred embodiment, the flexible capillary tube 110 is made of a transparent material, in order to allow visual inspection of the additive content.
The fittings 120, 130 are monolithically fixed to the flexible capillary tube 110 to form a unitary piece. In a preferred embodiment, the whole bending unit 100 is disposable. For example, the fittings are constructed of a molded plastic, e.g. Nylon.
The fitting 130 has an outer thread 131 to be connected to the internal thread of the Luer coupling 16″ of the threaded nozzle 16 of the cartridge 12 and a frusto-conical inner portion 132 configured to receive the frusto-conical outlet tube 16′ of the nozzle 16 of the cartridge 12.
The fitting 120 has a frusto-conical outlet tube 121 surrounded with a “Luer” coupling 122 which comprises an internal thread. The frusto-conical outlet tube 121 is designed to be received by the inner frusto-conical portion 21′; 210′ of the adapter 20; 200. The internal thread of the “Luer” coupling 122 is designed to be connected to the outer thread of the first end portion 20′, 200′ of the adapter 20; 200.
Advantageously, the bending unit has a maximum additive content of less than 0.2 ml, e.g. of 0.160 ml. In this manner, All the amount of additive to be charged in the air conditioning or refrigeration system is really injected therein, since no additive can remain in any intermediate part.
Another advantage of the apparatus 10 is that it is entirely disposable.
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 arrangement 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.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14210489 | Mar 2014 | US |
| Child | 16516820 | US |
