AU660129B1

AU660129B1 - Quick connect swivel coupling

Info

Publication number: AU660129B1
Application number: AU68818/94A
Authority: AU
Inventors: Daniel F Kiblawi; Bruce D Terry
Original assignee: Automotive Fluid Systems Inc
Current assignee: Automotive Fluid Systems Inc
Priority date: 1993-10-22
Filing date: 1994-07-29
Publication date: 1995-06-08
Anticipated expiration: 2014-07-29
Also published as: ITMI941958A1; FR2711761B1; CZ170494A3; PT101584A; FR2711761A1; IT1270089B; JPH07293776A; ES2121492B1; CA2127506A1; GB2283070A; ITMI941958A0; DE4432562A1; GB9414547D0; ES2121492A1

Description

1

AUSTRALIA

Patents Act 1990 AUTOMOTIVE FLUID SYSTEMS, INC.

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT c e r r 660129 Invention Title: "Quick connect swivel coupling" The following statement is a full description of this invention including the best method of performing it known to us:- BACKGROUND OF THE INVENTION i: FIELD OF THE INVENTION The present invention generally relates .to connections for securing refrigerant hoses or tubes to a housing or body. More specifically, this invention relates to a quick connect coupling which can be operated with one hand to selectively couple and uncouple one or two air conditioning refrigerant lines with an expansion valve body, compressor Smanifold, or a condenser block wherein the quick connect coupling incorporates a safety feature which positively secures the refrigerant lines until the refrigerant line pilot clears the mating connection refrigerant lines.

2. DESCRIPTION OF THE PRIOR ART The air conditioning system of an automobile conventionally 9.* 15 includes an expansion valve or fixed orifice which delivers a high pressure liquid refrigerant from the system's condenser to an evaporator, where the refrigerant is vaporized. The refrigerant is then drawn from the condenser by a vacuum created by the system's compressor, where the vaporized refrigerant is compressed and redelivered to the condenser. The condenser returns the refrigerant to a liquid state before being returned to the expansion valve or orifice.

The system components of an air conditioning system are typ-ca±ly interconnected with refrigerant-carrying lines such as tubes, hoses, or a combination of both. To per-it the connecting joint to be serviced in the field, it is generally preferable to couple refrigerant lines interconnecting the system components in a manner that readily permits disassembly. Various methods and devices for coupling refrigerant lines within the system have been suggested, as illustrated in U.S. Patent Nos.

3,869,153 and 3,929,356 to DeVincent et al.

For convenience, it is often preferable to couple the refrigerant lines interconnecting the system components in pairs. Such an arrangement allows the paired refrigerant lines to be simultaneously coupled with or uncoupled from the expansion valve body. Examples of coupling devices configured to achieve such a result are taught in U.S. Patent No. 3,869,152 to DeVincent et al. and U.S. Patent No. 4,468,054 to Orth.

A disadvantage with the coupling device taught by DeVincent et al.

is the complicated design of the device. The coupling device is composed of a cooperating pair of brackets, each of which must be physically interlocked with a clamp fitted to each refrigerant line. The assembly is secured by flanges formed on each clamp which must be bent to interlock the assemb..y.

Accordingly, the coupling device taught by DeVincent et al. permits only limited field servicing, in that the flanges will eventually fatigue and fracture.

**oo 15 Orth teaches a coupling device which can be more easily removed in service, and substantially without the concern for the formation of fatigue fractures in the device. The coupling device is composed of a flat plate having a pair of apertures formed therein. Each aperture is slotted, with each slot extending from its respective aperture to the periphery of the 20 plate. The apertures and slots are sized to closely receive a pair of tubes. Each tube is formed with an annular upset bead whose diameter is larger thin the diameter of its corresponding aperture. The plate is installed by slipping each tube through one of the slots and into one of the apertures, such that each tube's bead is between the plate and the end of the tube. As the plate is secured to an expansion valve body with a fastener, the periphery of each aperture abuts its corresponding bead.

Tightening the plate to the expansion valve body traps each bead between the plate and valve body, so as to positively secure the tubes to the valve body.

While the coupling device taught by Orth can potentially be operated with a single hand, a disadvantage with this coupling device is that two hands are required in order to more readily uncouple the refrigerant lines from the valve body. Specifically, the tubes cannot be readily disconnected from the valve body until the plate is completely removed, and the fastener must be completely removed before the plate can be removed. While it is at times a matter of convenience to require only one hand to operate a device, the limited amount of space within the engine compartment of an automobile often makes it difficult, if not impossible, for service personnel to use two hands to couple or uncouple the air conditioning refrigerant lines interconnecting the system components.

An additional disadvantage with the coupling device taught by Orth is that, if the plate is sufficiently loosened or a tube is sheared at the valve body, it is possible for a tube to slip out of its aperture through the corresponding slot. The potential for such an occurrence exists because the width of each slot is slightly greater than the diameter of its 15 corresponding tube.

o *From the above discussion it can be readily appreciated that the prior art does not disclose a device for coupling a pair of air conditioning refrigerant lines interconnecting the system components, wherein the coupling device can be readily operated with one hand to permit coupling and 20 uncoupling of the refrigerant lines interconnecting the system components.

Furthermore, the prior art does not disclose a coupling device which is able to reliably secure the refrigerant lines even after the refrigerant lines have become disengaged from the system components.

Accordingly, what is needed is a reusable coupling device suitable for use in the automotive industry to couple a pair of air conditioning refrigprant lines between air conditioning system components, wherein the coupling device is capable of being operated with a single hand to allow the refrigerant lines to be uncoupled from the respective system components for service, while simultaneously providing a safety feature which prevents the refrigerant lines from becoming accidently or prematurely disengaged from the coupling device, even after the coupling device has become partially loosened.

SUMMARY OF THE INVENTION According to the present invention there is provided a quick connect coupling for securing a pair of air conditioning refrigerant lines between components of an automotive air conditioning system. The quick connect coupling is capable of being operated with one hand so as to allow both refrigerant lines to be simultaneously disconnected from the expansion valve body. The quick connect coupling also incorporates a safety feature which prevents the refrigerant lines from being disengaged from the coupling unless the coupling is sufficiently loosened so as to be rotatable out of 10 engagement with the refrigerant lines.

Conventionally, the system component includes a pair of bosses, each of which is equipped to be engageable with a pair of air conditioning refrigerant lines. In accordance with this invention, each refrigerant line terminates with an enlarged diameter portion from which a flange portion extends radially. Each enlarged diameter portion is sized to closely couple with a corresponding pilot member provided by the system component. In ac:ordance with this invention, each pair of refrigerant lines is secured to the system component with a single quick connect coupling which is rotatably mounted to the system component.

The quick connect coupling is generally a clamping member which is configured to engage the flange portions of the pair of refrigerant lines, and clamp the flange portions against the system component when the quick connect coupling is fully secured with a suitable fastener. The clamping member includes a pair of apertures, each of which is sized to receive one of the refrigerant lines. More specifically, each aperture is sized to closely receive the enlarged diameter portion of its corresponding refrigerant line.

A particular aspect of this invention is that at least one of the apertures has a retention feature which is contiguous with the aperture and the periphery of the clamping member. The retention feature allows limited access by the corresponding refrigerant line to the aperture. More particularly, the access provided by the retention feature has a maximum width which is less than the diameter of its corresponding aperture and the enlarged diameter portion of the corresponding refrigerant line, but is greater than the diameter of the refrigerant line immediately adjacent the enlarged diameter portion. As a result, the refrigerant line can only be inserted into the aperture by passing the smaller diameter portion of the refrigerant line through the retention feature, a maneuver which can be accomplished by rotating the clamping member about an axis of rotation which is 'substantially normal to ehe surface of the system component. When the clamping member is moved into engagement with the refrigerant line's enlarged diameter portion, the refrigerant line is effectively prevented from becoming dislodged from the aperture unless the clamping member is again aligned with the smaller diameter portion of the refrigerant line.

.The clamping member is secured to the system component so as to permit the clamping member to rotate about an axis which is substantially normal to the surface of the system component. Accordingly, the clamping *06. member cannot be rotated unless the clamping member is displaced relative to the system component, such that the aperture with the retention feature is disengaged from the enlarged diameter portion of its refrigerant line and aligned with the refrigerant line's smaller diameter portion.

According to a preferred aspect of this invention, the quick connect coupling described above is an uncomplicated, reusable and relatively low cost device which can reliably secure a pair of refrigerant lines to a system component. The clamping load necessary to secure the refrigerant lines to the system component can be generated with a single fastener which also serves to secure the quick connect coupling to the system component.

In addition, the quick connect coupling of this invention is capable of being operated with a single hand, so as to allow the refrigerant lines to be coupled and uncoupled from the system component with only a minimal amount of clearance within an engine compartment. Uncoupling of the refrigerant lines only requires that the quick connect coupling be sufficiently loosened so as to align the retention feature with the smaller diameter portion of its corresponding refrigerant line, such that the quick connect coupling can be rotated clear of the refrigerant line.

In addition, a significant advantage of the present invention is that the quick connect couplin, incorporates a safety feature which prevents the refrigerant lines from becoming disengaged from their respective apertures unless the quick connect coupling has been sufficiently loosened so as to align the retention feature with the smaller diameter portion of its corresponding refrigerant line. As a result, the refrigerant lines are restrained and remain coupled to the quick connect coupling while the sealing member of the quick connect coupling is moved clear of its mating part, allowing the refrigerant, under pressure, to escape without dislodging the tube from the system component, even if the quick connect coupling is o 15 partially loosened.

Accordingly, it is an object of the present invention to provide a coupling device for simultaneously securing a pair of refrigerant lines to an air conditioning system component, such as a pair of air conditioning refrigerant lines to an expansion valve body.

20 It is a further object of the invention that the coupling device be operable with a single hand, so as to allow an operator to couple and uncouple the refrigerant lines from the system component with minimal clearance between the system component and its surrounding environment.

It is still a further object of the invention that the coupling device incorporate a positive retention feature which cooperates with an enlarged diameter portion of at least one of the refrigerant lines to positively retain the refrigerant line within an aperture formed in the coupling device.

It is another object of the invention that the retention feature be formed so as to permit selective disengagement of at least one of the refrigerant lines with the coupling device.

It is yet another object of the invention that the coupling device be securable to the system component with a single fastener which also serves to generate a clamping load that secures the refrigerant lines to the system component.

It is still another object of the invention that the coupling device be uncomplicated, reusable and relatively low cost.

Other objects and advantages of this invention will be more 0 apparent after a reading of the following detailed description taken in conjunction with the drawings provided.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an automotive ai- conditioning expansion valve body equipped with a quick connect coupling in accordance with a preferred embodiment of this invention; Figure 2 is a cross-sectional side view of the expansion valve 15 body taken along lines 2-2 of Figure 1 in accordance with the preferred embodiment of this invention; 9 Figure 3 is an isolated view of the clamping member of the quick connect coupling of Figures 1 and 2; and *Figure 4 is a cross-sectional side view of a portion of an .999 20 alternative expansion valve body and conduit assembly equipped with the 99 quick connect coupling of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to Figure 1, there is shown an expansion valve body for an automotive air conditioning system. As illustrated, the expansion valve body 10 is configured to be coupled with a pair of air conditioning refrigerant lines 14 and 16. A pair of mounting bolts 12 enables the expansion valve body 10 to be mounted within the engine compartment of an automobile in a conventional manner.

It is conventional to furnish an expansion valve body with a pair of oppositely disposed surfaces, only one of which is shown in Figure 1.

Each boss is equipped to receive a corresponding pair of refrigerant lines, as illustrated in Figure 1. Typically, a first refrigrant line, such as the refrigerant line 14, is coupled to the expansion valve body 10 and delivers high pressure liquid refrigerant from the air conditioning system's condenser (not shown) to the expansion valve body 10, while a second refrigerant line 16 on the opposite boss delivers the refrigerant at a much lower pressure to the system's compressor (not shown), where the refrigerant is compressed. A third refrigerant line (not shown), transports the compressed refrigerant from the compressor to the condenser (not shown).

In accordance with a preferred embodiment of this invention, at least one of the pair of refrigerant lines 14 and 16 is secured to the expansion valve body 10 with a quick connect coupling 20 which is rotatably mounted to the expansion valve body 10 with a threaded fastener 18 and a washer 44. Preferably, the fastener 18 is received within a bolt hole 36 0* which is intermediate a pair of apertures 38 and 40 formed in the quick connect coupling 20. The pair of apertures 38 and 40 are sized to closely C receive the refrigerant lines 14 and 16, respectively. The quick connect *fee 0000 coupling 10 secures the pair of refrigerant lines 14 and 16 to the expansion valve body 10 by engaging radial flanged portions 46 and 48 formed on the .refrigerant lines 14 and 16, respectively. The flanged portions 46 and 48 are clamped to the expansion valve body 10 by the quick connect coupling Accordingly, the quick connect coupling 20 is preferably formed from a suitably strong material, such as ASH 6061 aluminum alloy, though it is foreseeable that other structural materials, such as an engineering plastic or steel, could be used.

As shown in Figure 2, the flanged portions 46 and 48 are formed at the terminal ends of the refrigerant lines 14 and 16. The terminal ends define enlarged diameter portions 52 and 54 of the refrigerant lines 14 and 16, respectively. The enlarged diameter portions 52 and 54 are sized to fit over appropriately sized inserts 26 and 28, respectively. The inserts 26 and 28 are preferably permanently secured within the expansion valve body _Y C by an interference fit integrated with an O-ring seal or, more preferably, by being brazed or welded within their corresponding bores 22 and 24. The inserts 26 and 28 serve to pilot the enlarged diameter portions 52 and 54, respectively, as the refrigerant lines 14 and 16 are being coupled with the S expansion valve body 10. Preferably, each insert 26 and 28 is provided with a pair of seals 30 which are disposed between backup rings 32. As is conventional, the seals 30 must be formed from an elastic material which is i* compatible with an air conditioning cooling refrigerant, which is conventionally the refrigerant R-134-a. A conventionally suitable, material 10 for the seals 30 is HNBR or Neoprene, while a suitable material for the

S.

o. backup rings 32 is a nylon, though it is foreseeable that other materials could be used.

In a conventional manner, the refrigerant line 16 and its 4..

oe corresponding enlarged diameter portion 54, insert 28, seals 30, backup rings 32 and aperture 40 are each illustrated as being larger than their counterparts corresponding to the refrigerant line 14.

0*66 From Figures 1 and 3, it can be seen that the quick connect coupling 20 of the preferred embodiment is generally S-shaped, with each S* aperture 38 and 40 being provided with a retention feature in the form of a chamfered slot 42a and 42b, respectively. In accordance with this invention, the maximum width of each slot 42a and 42b is less than the outer diameter .of the enlarged diameter portion 52 and 54 of its corresponding refrigerant line 14 and 16, as can be more readily seen in Figure 1. The purpose of this feature is to prevent the refrigerant lines 14 and 16 from becoming disengaged with their respective apertures 38 and 40 while the quick connect coupling 20 is engaged with the enlarged diameter portions 52 and 54 of the refrigerant lines 14 and 16. To disengage the refrigerant lines 14 and 16 from the quick connect coupling 20, the quick connect coupling 20 must be aligned with a smaller diameter region 56 and 58 of the refrigerant lines 14 and 16 above the enlarged diameter portions 52 and 54, so as to enable the refrigerant lines 14 and 16 to disengage their corresponding apertures 38 and 40 by passing through the slots 42a and 42b, respectively. While the slots 42a and 42b are each illustrated as being formed with a chamfer, it is foreseeable that the geometry of the slots 42a and 42b could be considerably altered while still providing the functional aspects of the slots 42a and 42b, namely, the ability to retain the refrigerant lines 14 and 16.

Aligning the quick connect coupling 20 with the smaller diameter regions 56 and 58 of the refrigerant lines 14 and 16 requires the quic connect coupling 20 to be displaced from the expansion valve body Preferably, the fastener 18 is formed to be long enough to allow the quick connect coupling 20 to be sufficiently backed off from the expansion valve body 10 without requiring removal of the fastener 18. As a result, the fr tener 13 is able to serve as a pivot that defines an axis of rotation which is substantially nL mal to the surface of the expansion valve body Accordingly, the quick connect coupling 20 is able to rotate free of the refrigerant lines 14 and 16 once the apertiures 38 and 40 clear the enlarged diameter portions 52 and 54 of the refrigerant lines 14 and 16.

S* Preferably, a compression spring 34 is provided in a countersink 50 formed in the expansion valve body 10 which circumscribes the fastener 18. The spring 34 biases the quick connect coupling 20 in a direction away from the expansion valve body 10, so as to eliminate the requirement to manually lift the quick connect coupling 20 away from the expansion valve body 10. Consequently, as the fastener 18 is loosened, the quick connect coupling 20 is automatically displaced from the expansion valve body Sufficient loosening of the fastener 18 eventually aligns the apertures 38 and 40 with the smaller diameter regions 56 and 58 of the refrigerant lines 14 and 16, which permits the quick connect device 20 to be rotated relative to the expansion valve body 10. As the quick connect coupling 20 is rotated, the refrigerant lines 14 and 16 pass out of their respective apertures 38 and 40 through their respective slots 42a and 42b.

With the quick connect coupling 20 descril above, a novel method is enabled for coupling and uncoupling the pair of refrigerant lines 14 and 16 from the expansion valve body 10. The method for coupling the refrigerant lines 14 and 16 to the expansion valve body 10 is generally commenced by connecting the refrigerant lines 14 and 16 to their respective inserts 26 and 28. Preferably, the quick connect coupling 20 is previously mounted to the expansion valve body 10 prior to connecting the refrigerant lines 14 and 16 to the expansion valve body 10, so as to avoid the requirement to maneuver the fastener 1B between the refrigerant lines 14 and 16 in order to mount the quick connect'coupling 20. The quick connect coupling 20 is then coupled with the refrigerant lines 14 and 16 by rotating the quick connect *coupling 20 about the fastener 18 so as to slip the refrigerant lines 14 and 16 through their respective slots 42a and 42b and into their respective apertures 38 and 40. C'amping of the flanged portions 46 and 48 of the 15 refrigerant lines 14 and 16 can then be achieved simply by tightening the fastener 18 until the cquick connect coupling 20 clamps the flanged portions :t o 46 and 48 against the surface of the expansion valve body Uncoupling of the refrigerant lines 14 and 16 simply involves loosening the fastener 18 so as to permit the compression spring 34 to 20 disengage the quick connect coupling 20 from the flanged portions 46 and 48 of the refrigerant lines 14 and 16, and displace the quick connect coupling away from the surface of the expansion valve body 10. The fastener 18 is loosened to the degree necessary to allow the apertures 38 and 40 to be displaced from the enlarged diameter portions 52 and 54 of the refrigerant lines 14 and 16, so as to allow the quick connect coupling 20 to be rotated about the fastener 18. By rotating the quick connect coupling 20, the refrigerant lines 14 and 16 are disengaged from their respective apertures 38 and 40 and pass through their corresponding slots 42a and 42b, so as to free the refrigerant lines 14 and 16 from tY- quick connect coupling The refrigerant lines 14 and 16 can then be disconnected from their inserts 26 and 28 to allow servicing of the expansion valve body 10 or replacement of the refrigerant lines 14 and 16.

The quick connect coupling 20 of this invention is also suitable for securing refrigerant lines which differ structurally from that shown in Figures 1 and 2. With reference to Figure 4, there is represented a second valve body 110 which employs a pair of refrigerant lines that, in a manner similar to the refrigerant lines 14 and 16 of Figure 2, are to be secured to the expansion valve body 110. Only one of the refrigerant lines are illustrated in Figure 4, for the sake of brevity.

The refrigerant line 116 shown in Figure 4 corresponds to the refrigerant line 16 of the first embodiment, and includes a small diameter region 158 and an enlarged diameter portion 154 formed at one end thereof.

The enlarged diameter portion 154 is sized to be received in a bore 124 formed in the expansion valve body 110, as shown. The refrigerant line 116 differs structurally from that shown in Figure 2 by having a swaged flange 148 formed on the enlarged diameter portion 154. The swaged flange 148, 15 which can be formed in any suitable manner, is clamped against the surface of the expansion valve body 110 by the quick connect coupling 20 of this c. invention. A pair of aeals 130, corresponding to the seals 30 employed in Figure 2, are received in a pair of grooves 132 formed in the bore 124. As before, the seals 130 provide a refrigerant-tight seal between the 9 20 refrigerant line 116 and the expansion valve body 110. Because the seals 130 are to be installed prior to insertion of the refrigerant line 116 into the bore 124, it is preferable to form a chamfer 128 on the refrigerant line 116 so as to reduce the likelihood of damaging the seals 130 during assembly.

In use within the environment described above, the quick connect coupling 20 functions in a substantially identical manner as that shown in Figure 2. The quick connect coupling 20 is mounted to the expansion valve body 110 with a fastener (not shown), such that the quick connect coupling is able to pivot about the fastener when sufficiently displaced from the surface of the expansion valve body 110. Tightening the fastener causes the quick connect coupling 20 to clamp the swaged flange 148 to the expansion valve body 110, so as to positively retain the refrigerant line 116 within the bore 124. The refrigerant line 116 cannot be removed from the bore 124 until the quick connect coupling 20 is sufficiently displaced from the expansion valve body 110 by loosening the fastener, at which point the quick connect coupling 20 can be pivoted in order to rotate clear of the refrigerant line 116. Accordingly, this safety feature is present with each of the two environments disclosed for the quick connect coupling 20 of this invention.

From the above, it can be seen that a significant advantage of 10 this invention is that the quick connect coupling 20 of this invention is capable of being loosened and tightened with a single hand, so as to allow S* refrigerant lines to be coupled and uncoupled from an expansion valve body with minimal clearance within an engine compartment. Specifically, uncoupling of the refrigerant lines requires only that the quick connect 15 coupling 20 be sufficiently displaced from the expansion valve body so as to align the slots 42a and 42b with the smaller diameter region of the corresponding refrigerant line, such that the quick connect coupling can be rotated to allow the refrigerant lines to be disconnected from the expansion valve body.

20 Another significant advantage of the present invention is that the refrigerant lines cannot be disengaged from the expansion valve body unless the quick connect coupling 20 has been sufficiently loosened so as to align the slots 42a and 42b with the smaller diameter region of their corresponding refrigerant lines. As a result, the refrigerant lines are positively restrained and remain coupled to the expansion valve body, even if the quick connect coupling 20 is partially loosened.

In addition, the advantages of the quick connect coupling can be realized with minimal hardware and can be readily adapted to a conventional expansion valve body. Accordingly, the quick connect coupling of this invention is an uncomplicated coupling device which is relatively inexpensive and reusable, yet is able to reliably secure a pair of refrigerant lines to an expansion valve body without requiring significant space within the engine compartment and without contributing significant weight to the vehicle.

While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the shapes of the quick connect coupling 20, the apertures 38 and 40, and the slots 42a and 42b could be modified from that shown in the Figures, the quick connect coupling 20 could be secured to an expansion valve body with a fastening device other than the threaded fastener shown, the manner in which the refrigerant lines are interconnected to the expansion valve body could be altered, and the quick connect coupling 20 could be used in applications other than to secure air conditioning refrigerant lines to an expansion valve body. Accordingly, the scope of the invention is to be limited only by the following claims.

Claims

6.i 13 corresponding one of said air conditioning refrigerant lines. 1 16. A method for coupling a pair of conduit members to a body, 2 said method comprising the steps of: 3 rotatably mounting a clamping member to said body, said 4 clamping member having a first receiving means formed therein; rotating said clamping member such that a first diameter 6 portion of a first member of said pair of conduit members passes through a 7 slot formed in said clamping members so as to engage said first receiving 8 means; 9 displacing said clamping member toward said body such that said first receiving means engages an enlarged diameter portion of said 11 first member; 12 further displacing said clamping member toward said body such 13 that said clamping members engages flanged portions formed on said pair of 14 conduit members; and securing said clamping member to a surface of said body so as 16 to clamp said flanged portions of said pair of conduit members to said 17 surface of said body. 1 17. The method of Claim 16 wherein said rotating step includes 2 passing a second member of said pair of conduit members through a slot so as 3 to engage a second receiving means formed in said clamping member. L 18. The method of Claim 17 wherein said displacing step includes 2 engaging said second receiving means with an enlarged diameter portion of a 3 said second member. a. 1 19. The method of Claim 16 wherein said displacing, said further 2 displacing and said securing steps include threadably tightening a fastener 3 which secures said clamping member to said body. 1 20. The method of Claim 19 wherein said rotating step includes 2 rotating said clamping member about said fastener. DATED THIS 29 DAY OF JULY 1994 AUTOMOTIVE FLUID SYSTEMS, INC. Patent Attorneys tor the Applicant:- F.B.RICE CO.