Fluid coupling

A fluid coupling is disclosed. The fluid coupling includes first and second coupling parts which define a passageway. A valve is provided in the passageway. The valve is adapted to open upon interconnection of the coupling parts. One of the coupling parts includes at least one guide groove, while the other coupling part includes at least one key pin receivable by the guide groove. The coupling parts can only be interconnected upon alignment of the key pin with the guide groove.

BACKGROUND OF THE INVENTION 
The present invention relates to a fluid coupling and particularly to a 
two-part or two piece fluid handling coupling. Fluid couplings of this 
type are often used to join conduits together. For example, low spill 
hydraulic lines may be connected together with a two-part fluid handling 
coupling. In the chemical industry, fluid couplings are used to join 
conduits or hoses to fill and dispense chemicals from tanks. 
The primary objective of the present invention is to provide an improved 
fluid coupling which includes a keying system to ensure that only the 
correct male coupling part or half can be connected to the mating female 
coupling part or half. This prevents cross-mixing of fluids. 
SUMMARY OF THE INVENTION 
The present invention is directed to a fluid coupling having 
interconnectable male and female coupling parts or halves. Each of the 
coupling parts includes a coupling connection end and an axial passageway. 
The coupling parts include a valve adapted to open upon interconnection of 
the male and female coupling parts. One of the coupling parts includes at 
least one guide groove. The other of the coupling parts includes at least 
one key pin receivable by the guide groove. The key pin and guide groove 
must be aligned to interconnect the parts. If there are insufficient guide 
grooves or if the guide grooves are not in correct circumferential 
alignment with the key pins, the coupling parts cannot be interconnected. 
The fluid coupling, according to the present invention, ensures that the 
correct coupling parts are joined together and tends to prevent conduit or 
container connections which are improper.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, a fluid coupling, according to the present 
invention, is generally indicated by the reference number 10. The fluid 
coupling 10 is described in detail below. Another embodiment of a fluid 
coupling, similar to the fluid coupling 10, is disclosed in the assignee's 
U.S. pat. application No. 07/726,031 filed July 5, 1991 now U.S. Pat. No. 
5,123,446 issued Jun. 23, 1992. That disclosure is incorporated herein by 
reference. 
The fluid coupling 10 includes first and second coupling parts. The parts 
include an interconnectable female coupling part 11 and an 
interconnectable male coupling part 13. 
The female part 11 includes an outer tube 14. A longitudinal passageway 15 
is defined within the tube 14 and is generally parallel with a 
longitudinal axial centerline 17. An adaptor 18 is threadably connected to 
the tube 14. Threads 19 of the adaptor 18 permit the female coupling part 
11 to be connected to a tool fitting or to a conduit, for example a tube 
fitting 21, as shown in FIG. 3. 
A spider 22 is mounted within the passageway 15 and is provided with 
openings 20 whereby fluid may flow therethrough. The spider 22 supports a 
valve stem 23 which terminates at a valve head 24. A seal 25 is positioned 
adjacent the valve head 24. 
A tubular valve sleeve 26 is reciprocally mounted within the passageway 15 
and surrounds the valve stem 23. The valve sleeve 26 includes an outwardly 
extending shoulder 27. A compression spring 28 engages the shoulder 27 and 
urges the valve sleeve 26 toward the right, as shown in FIG. 3. 
An annular detent sleeve 30 surrounds the valve sleeve 26 and includes an 
inwardly directed shoulder 27. The detent sleeve 30 is positioned between 
the tube 14 and the valve sleeve 26 and functions as a lost-motion means 
for operating the valve sleeve 26. A compression spring 32 biases the 
detent sleeve 30 toward the right, as shown in FIG. 3. 
The connecting or locking of the parts of the connector parts 11 and 13 
together is accomplished by an annular lock collar 35 which is 
reciprocally mounted on the tube 14. The lock collar 35 includes an 
internal groove 34 defining an inclined surface 36. Detent balls 37 are 
biased inwardly into engagement with the detent sleeve 30 by the biasing 
force of a compression spring 38 which tends to move the lock collar 35 to 
the right, as shown in FIG. 3. When the fluid coupling 10 is in the 
connected position, as shown in FIG. 3, the detent balls 37 are positioned 
in a groove 39 and the lock collar 35 is moved to the position, shown in 
FIG. 3, to maintain the female and male parts 11 and 13 in the locked or 
interconnected mode, shown in FIG. 3. 
A seal 40 is positioned adjacent the spider 22, to provide a seal with the 
tube fitting 21. Seals 41 and 42 are provided in a surrounding and opposed 
relationship with the valve sleeve 26. 
The male coupling part 13 includes a generally tubular body 45 which 
defines internal threads 46 adjacent an outer end 47. In the present 
embodiment, a tube fitting 48 is threadably connected to the outer end 47 
of the tubular body 45. Various types of fittings may be utilized other 
than the fitting 48. 
The tubular body 45 defines a longitudinally extending axial passageway 49. 
The passageway 49 is in alignment with the passageway 15 of the female 
coupling part 11 to provide an overall passageway through the entire fluid 
coupling 10. A seal 50 is provided adjacent the inner end of the tube 
fitting 48. 
A spider 52 is located within the passageway 49 of the tubular body 45 and 
defines a plurality of fluid passageways 51 whereby fluid may pass through 
the spider 52. The spider 52 also defines an elongated spider bore 53. A 
poppet valve 54, having an outer end 55 and a tubular shank 56, is mounted 
adjacent the spider 52. The tubular shank 56 of the poppet valve 54 is 
mounted for reciprocation within the spider bore 53. A compression spring 
57 urges the outer end 55 of the poppet valve 54 to the left, as shown in 
FIG. 3. 
Referring to FIGS. 2 and 3, an important feature of the present invention 
is a keying assembly. In the present embodiment, a plurality of grooves, 
namely two guide grooves 60 are located on a nose surface 61 of the male 
connector part 13. In the present embodiment, the guide grooves 60 are 
located in a diametrically opposed relationship, 180.degree. apart from 
one another. However, the number of grooves and their circumferential 
positioning with respect to the nose surface 61 may be varied and still 
fall within the scope of the present invention. The guide grooves 60 are 
parallel to the centerline 17 of the coupling parts 11 and 13. 
Key pins 63 are positioned on the second part of the fluid coupling 10. In 
other embodiments, the grooves can be placed in the female part while the 
keys are placed in the male part. In the present embodiment, the key pins 
63 are mounted on the annular lock collar 35 of the female coupling part 
11. Two key pins 63 are provided and extend inwardly perpendicular to the 
centerline 17 of the respective coupling parts 11 and 13. 
Referring to FIG. 2, when the coupling parts 11 and 13 are in a 
disconnected mode, in order to connect the parts, the key pins 63 must be 
received by aligned grooves 60. In the present embodiment, as indicated in 
FIG. 2, the diametrically opposed key pins 63 are suitable for alignment 
with the two diametrically opposed guide grooves 60. Therefore, as shown 
in FIG. 3, the first and second coupling parts 11 and 13 may be moved from 
the disconnected position shown in FIG. 2, where the valving is closed, to 
the connected position shown in FIG. 3, where the valving is open and the 
fluid passageways 15 and 49 are aligned allowing fluid to pass through the 
connected fluid coupling 10. 
The fluid coupling 10 of the present invention requires at least one lock 
pin 63 and at least one mating guide groove 60. However, as mentioned 
above, the location of the guide grooves and the lock pins may be reversed 
with respect to the female and male connectors, and still fall within the 
scope of the present invention. In addition, there can be a varying 
plurality of lock pins and connectors. There always must be sufficient 
aligned guide grooves to mate with the number of lock pins provided in 
order to permit the fluid coupling 10 to be connected. However, there may 
be additional guide grooves provided in excess of the number of lock pins 
provided. In addition, the circumferentially positioning of the lock pins 
and guide grooves may be varied. For example, rather than having the 
locking pins at twelve o'clock and six o'clock, as shown in FIG. 2, the 
pins could be, for example, at twelve o'clock and two o'clock. Or in the 
alternative, four pins could be provided. One each located at twelve 
o'clock, three o'clock, six o'clock and nine o'clock, with corresponding 
aligned grooves on the other connector part. 
Referring to FIG. 1, a use of a fluid coupling 10', according to the 
present invention, is diagrammatically illustrated. Three chemical 
containers 66, 67 and 68 are indicated. The three containers 66, 67 and 68 
contain chemical solutions which are different from one another. Each of 
the containers 66-68 includes a conduit 69 which mount respective first 
coupling parts 70, 71 and 72, according to the present invention. In the 
present embodiment, the first coupling parts 70-72 are female coupling 
halves and each has a different number or circumferential alignment of key 
pins. These first coupling parts 70-72 mate with second coupling parts, 
which are male coupling halves. A second coupling part 74 is attached to a 
conduit supply line 77 and includes guide grooves which are of the correct 
number and alignment of the first coupling part 71. A supply container 79 
is connected through a pump and motor assembly 80 to the conduit supply 
line 77. The supply container 79 contains the same chemical solution which 
is desired in the container 67. Because the second coupling 74 will only 
mate with the first coupling part 71 of the container 67 and will not mate 
with the first coupling parts 70 and 72 of the containers 66 and 68, the 
supply container 79 can only be connected to the correct container 67. In 
other embodiments, the coupling part connected to the container is mounted 
on the top of the container. 
The use shown in FIG. 1 is only one use of the fluid coupling 10, according 
to the present invention. The fluid coupling, according to the present 
invention, may also be used in connection with tool supply systems where 
fluid conduits under specified fluid pressures are desired for certain 
tools. Again, the key system, found in the fluid couplings, according to 
the present invention, ensure that a proper connection is made. While the 
present invention may be utilized in high pressure systems, most 
applications fall within a low pressure field for the chemical industry 
with operating pressures generally in the range of 10 psig to 100 psig. 
Many modifications and revisions may be made to the fluid coupling, 
disclosed in the present application without departing from the spirit and 
the scope of the present invention and of the following claims.