Device for preventing refrigerant leaks in air conditioning system service ports

A device for preventing refrigerant leaks in air conditioning system service ports includes a coupler to be coupled to the service port. A main body has a longitudinal direction and is disposed adjacent the coupler in the longitudinal direction. A stem is movable inside the main body in the longitudinal direction. A sealing element is disposed adjacent the stem. A head which is fastened to the main body has an internal thread, and a handle has a shaft with an external thread to be screwed into the internal thread of the head. The shaft has a free end remote from the handle for contacting the stem and pushing the sealing element adjacent the stem against an end of the service port upon turning the handle.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a device for preventing service ports in air conditioning systems from leaking refrigerant.

The main components of an air conditioning system are a compressor, a condenser, an evaporator, an expansion valve, a dryer or accumulator and refrigerant lines interconnecting the main components. Two refrigerant lines which are attached to the compressor are metal tubes having different diameters. The smaller diameter tube is a so-called high-pressure line and the larger diameter tube is a so-called low-pressure line. Each line has a service port which is used to service the air conditioning system. The service ports are each equipped with a check valve which is intended to prevent refrigerant leaks.

However, due to age, damage or soiling, the ports may begin to leak, requiring the system to be charged with refrigerant. The service ports cannot be replaced alone and instead the entire line to which the port is attached must be replaced. The lines cost several hundred and often more than one thousand Dollars. Simple plastic caps may prevent soiling of the port, but cannot prevent leakage.

Description of the Related Art

U.S. Patent Publication 2015/0184787A1 discloses an apparatus for sealing a pipe, not a port, to prevent refrigerant leaks. A cap assembly is provided with a washer 106. U.S. Patent Publication 2014/0069133A1 relates to an AC service port cap 11 in which a rubber plug 31 is placed in a seat 28 of a top 21 of the cap 11. The lower face of the plug has a bulge which extends partly into the port. U.S. Patent Publication 2014/0020781A1 teaches a locking mechanism for refrigerant line caps in which a cover 15 with a key 13 is applied into a housing body 12 for sealing a fill valve 75. U.S. Pat. No. 8,118,186B2 discloses a ratchet assembly for preventing slippage of a cap 100 for a service port 14. U.S. Pat. No. 3,985,007 relates to a screw cap 2 having a cap portion 1 and an inset member 11. A sealing washer 18 is disposed between the cap and the inset member 11. U.S. Pat. No. 3,843,015 teaches another screw cap having a cap part 1 for a threaded cap port 2. The cap part 1 extends around an overlapping rim 1′. Chinese Patent CN202646736U discloses a taper washer between a horn mouth of a connection tube and a taper joint.

None of the prior art documents adequately prevent refrigerant leaks in service ports of air conditioning systems.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a device for preventing refrigerant leaks in air conditioning system service ports, which overcomes the above-mentioned disadvantages of the heretofore-known devices of this general type and which ensures that even a refrigerant line having an aged, damaged or soiled port will be adequately sealed without the need to replace the port and thus the line.

With the foregoing and other objects in view there is provided, in accordance with the invention, a device for preventing refrigerant leaks in air conditioning system service ports. The device comprises a coupler to be coupled to an air conditioning system service port, a main body having a longitudinal direction and being disposed adjacent the coupler in the longitudinal direction, a stem movable inside the main body in the longitudinal direction, a sealing element adjacent the stem, a head fastened to the main body, the head having an internal thread, and a handle having a shaft with an external thread to be screwed into the internal thread of the head. The shaft has a free end remote from the handle for contacting the stem and pushing the sealing element adjacent the stem against an end of the service port upon turning the handle.

The device makes it possible to tightly press the sealing element against the end of the service port so that even if the valve in the service port leaks, refrigerant cannot escape.

In accordance with another feature of the invention, the coupler is a quick coupler having a detent for engaging in a groove formed in the service port. The detent may include a plurality of locking balls. Quick couplers are currently used for equipment that services air conditioning systems. They allow the equipment to be easily and quickly attached to service ports.

In accordance with a further feature of the invention, the sealing element is a disk-shaped washer, and the stem has one opening facing the coupler and receiving the washer. The stem may have a T-shaped cross section and a further opening facing the handle and receiving the free end of the shaft. The further opening may have a smaller diameter than the one opening. A stem spring is disposed between the head and the stem. The stem is therefore biased against the service port until the handle is turned, adding more pressure.

In accordance with an added feature of the invention, the main body is partially disposed within the coupler, the main body has a shoulder, the coupler has a shoulder, and a coupler spring surrounds part of the main body and is biased between the shoulder of the coupler and the shoulder of the main body permitting the coupler to act as a quick coupler with the service port. Although this represents one type of quick coupler, other types may be used in the invention.

In accordance with an additional feature of the invention, at least one O-ring is engaged in a groove formed in the one opening of the stem for sealing against an outer surface of the service port. The O-ring or O-rings provide an additional sealing effect for the service port.

In accordance with yet another feature of the invention, the coupler has a color identifying the device for use only on a low-pressure or high-pressure service port. This feature provides easy identification of the proper device to place on a particular service port.

In accordance with yet a further feature of the invention, according to a second embodiment, the sealing element is a cup, and the stem has one opening facing the coupler and receiving the cup. Once again, the stem may have a T-shaped cross section and a further opening facing the handle and receiving the free end of the shaft, the further opening having a smaller diameter than the one opening. The cup, which may be formed of rubber, may provide a larger contact surface with the outer surface of the service port than the O-ring.

In accordance with yet an additional feature of the invention, the main body has an inner surface with a step formed therein defining a stop preventing the stem from sliding beyond a predetermined distance in the main body toward the port. Therefore, the stem will be located in the proper position between the stop and the stem spring.

In accordance with a concomitant feature of the invention, the head is screwed to the main body, although any other suitable connection is possible.

Although the invention is illustrated and described herein as embodied in a device for preventing refrigerant leaks in air conditioning system service ports, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of the specific embodiment when read in connection with the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first, particularly, toFIGS. 1A and 1Bthereof, there is seen a device1for preventing refrigerant leaks in air conditioning system service ports. The device1includes a handle or cap2(also seeFIGS. 7A and 7B) having a threaded shaft4extending into a main body6(also seeFIGS. 10A-10C) attached to a coupler20, which will be described in detail below.FIG. 1Cshows the handle2and the main body6as well as two ports30,40to which the device1is to be attached. The port30having the larger diameter is the low-pressure port and the port40having the smaller diameter is the high-pressure port. The ports30,40are attached at their right side as shown in the figure to respective refrigerant lines. The ports30,40each have a respective undercut or groove32,42formed therein to which the device1is attached, a respective extension34,44beyond the undercut or groove, a collar38,48between the undercut or groove32,42and the extension34,44and a respective end36,46.

FIGS. 2A, 2B and 2Cshow a device1′ having a handle or cap2′ (also seeFIGS. 8A and 8B) with a threaded shaft4′, a main body6′ and a coupler20′. The device1′ is to be attached to a port30,40in the same manner described above with regard toFIGS. 1A-1C. The difference between the devices1and1′ is that the handle2is round whereas the handle2′ is elongated making it easier to distinguish between the devices1,1′. The couplers20,20′ are also provided in different colors. In particular, the coupler20on the device1for the low-pressure port30is blue whereas the coupler20′ on the device1′ for the high-pressure port40is red. The handles2,2′ may also be made in different colors. One of the devices will be used for the high-pressure port and the other will be used for the low-pressure port and the shapes and colors of the couplers and handles will prevent the user form attempting to use the wrong device for a particular port. However, since the ports and therefore the main bodies have different diameters, it is not possible to actually attach a device to the wrong port.

The exploded view ofFIG. 3shows the entire device1to be used on a port30,40. Although the device1will be described below, the explanations are the same for the device1′. The handle2having the threaded shaft4is seen at the left side of the figure. The handle2is followed by a head8having an external thread10, a stem spring12, a stem14(also seeFIGS. 9A-9C), two O-rings15, the main body6having holes16for receiving locking balls, a coupler spring18, a lock-release coupler20and a locking ring22. The coupler20is a quick coupler which has been modified for use in the device according to the invention.

The assembled device1is shown inFIGS. 4 and 5. It may be seen therein that the external thread of the shaft4is screwed into an internal thread5of the head8and the external thread10of the head8is screwed into an internal thread7of the main body6while enclosing the stem14and biasing the stem spring12between the head8and the stem14. The stem14is prevented from sliding too far toward the port30,40in the longitudinal direction of the main body6by a stop11, which is a step formed in the inner surface of the main body6. The coupler spring18is biased between a shoulder21of the coupler20and a shoulder9of the main body6. The two O-rings15are disposed in annular grooves formed in the stem14, although one O-ring may be used. The O-rings15are sealed against the outer surface of the extension34,44of the port30,40. The stem14has a T-shaped cross section defining a smaller opening17receiving the shaft4and a larger opening19receiving a disk-shaped washer or pad23, which may be formed of Teflon® (polytetrafluroethylene or PTFE), nylon, rubber or any other material suitable for sealing the end36,46of the port30,40. The holes16in the main body6are filled with locking balls24which are shown as being engaged in the undercut or groove32,42of the port30,40. However, another type of detent other than locking balls may be used. Finally, the locking ring22is snapped into a groove25formed in the main body6.

In order to attach the device1to the port30,40, the handle2is turned counter clockwise so that the shaft4is partially extracted from the head8. The user can then place the handle2in the palm of one hand and grasp the lock-release coupler20between the thumb and index finger of the same hand. The user then pulls the coupler20toward the handle2against the force of the coupler spring18and inserts the end36,46of the port30,40into the open end26of the main body6. Since the coupler20has been pulled toward the handle2, the locking balls24are adjacent a wider diameter recess27of the main body6which allows the collar38,48of the port30,40to slide past the locking balls24. The coupler20is then released and the coupler spring18pushes the coupler20away from the head8and locks the locking balls24in the undercut or groove32,42of the port30,40. The O-rings15are simultaneously sealed against the outer surface of the extension34,44of the port30,40.

The handle2is then turned in the clockwise direction causing the shaft4to be inserted father into the head8and to push the stem14so that the disk-shaped washer or pad23is pushed against the end36,46of the port30,40. The port30,40is locked in place by the locking balls24in the undercut or groove32,42so that an air-tight and liquid-tight seal is established between the disk-shaped washer or pad23and the end36,46of the port30,40. In order to release the port, the handle2is turned in the counter clockwise direction and the coupler20is retracted, freeing the port for removal.

In an alternative embodiment shown inFIG. 6, the disk-shaped washer or pad23and the O-rings15are replaced by a rubber cup28which sits inside the opening19and receives the end36,46and the extension34,44of the port30,40. The cup may also be formed of Teflon® or nylon or any other suitable sealing material.