Hose coupling

An arrangement for locking a male connecting member adapted to be inserted into a bore of a coupling member in which the female coupling member is provided with two cutouts generally at right angle to each other, of which one breaks through a portion of the wall forming the bore; a locking member of sheet-metal material is loosely inserted into the one cutout whereupon a spring is loosely placed over the locking member to urge the locking member inwardly, and a cap-like member is mounted over the female coupling member which covers externally the cutouts and holds the spring in place in prestressed condition.

The present invention relates to a locking arrangement for a coupling of 
the type, in which a connecting nipple is adapted to be axially secured 
within the bore of the female coupling member by the use of a spring ring 
or the like. 
Locking arrangements of the type described above are known as such in the 
prior art, as disclosed, for example, in my prior Swiss Pat. No. 397,358 
in which the straight portion of a spring ring, extending chord-like 
through a milled-out recess, is adapted to engage into an external annular 
groove in the connecting nipple when the latter is inserted into the bore 
of the coupling member. For purposes of enabling disconnection, a 
rotatable ring member itself provided with an actuating member in the form 
of a spring ring or screw, engages the free end of the straight portion of 
the spring ring when rotated in the appropriate direction so as to lift 
the straight portion out of the annular groove and thereby enable 
disengagement of the connecting nipple from the female coupling member. 
While couplings of the type described in my aforementioned Swiss patent 
proved commercially very successful because of their excellence in 
performance, they also entailed certain drawbacks as regards manufacture 
and assembly. More particularly, the parts of this type of prior art 
couplings not only involved relatively high manufacturing costs, but also 
were relatively costly to assemble. All prior attempts by me to obviate 
these shortcomings and drawbacks could be deemed, at best, only moderately 
successful. Moreover, other prior art couplings, based on the same 
principle of operation such as the U.S. Pat. No. 794,110 to McDowell, the 
U.S. Pat. No. 2,805,089 to Hansen, the Danish Pat. No. 75,910 to Hansen, 
the British Pat. No. 480,959 to Smith et al., and the Italian Pat. No. 
566,359 to High Pressure Components, Ltd. entail the same shortcomings and 
disadvantages as regards ease of manufacture and assembly. 
With ever-increasing labor and material costs, the success in the 
marketplace of any product is frequently dependent on its price 
competitiveness, taking into consideration its performance characteristics 
which, in case of a coupling, also involve considerations of energy 
savings in operation. 
The present invention is concerned with the primary task to provide a 
locking arrangement of the type described in my prior Swiss Pat. No. 
397,358 which assures the same high performance standards, yet permits a 
significant reduction in the costs of manufacture and assembly. 
Another drawback in the prior art couplings of this type resided in the 
dependence of the external dimensions of both the connecting nipple and 
the female coupling member on the diametric dimension of the fluid line 
reflected by the internal bore of the connecting nipple. In other words, 
for connecting nipples with larger external diameters, female coupling 
members of larger external diameters were normally necessary. Accordingly, 
another important object of the present invention resides in a coupling of 
the aforementioned type permitting far-reaching standardization of the 
parts by the use of female coupling members having the same external 
dimensions for connecting nipples of widely varying external diameters. 
The underlying problems are solved according to the present invention with 
a locking arrangement for a coupling of the type described above in that 
the female coupling member is provided with two cutouts formed by two 
recesses milled into the female coupling member substantially at right 
angles to each other, of which one breaks through the wall of the coupling 
member to provide a direct communication with the internal bore of the 
female coupling member, in that a locking or latching member of flat sheet 
metal material is inserted into the milled-out recess intersecting the 
internal bore of the coupling member and in that the sheet-metal locking 
or latching member is spring-loaded inwardly by a coil spring placed on 
the outside of the sheet-metal locking or latching member and is held in 
place by a rotatable cap-like member. No mechanical connection exists 
thereby between the latching member, the spring, and the cap-like member. 
According to a particularly advantageous construction of the present 
invention, the cap-like member is made of any suitable plastic material 
and includes one or two inwardly directed entrainment projections formed 
in one piece with the cap-like member. Additionally, the plastic cap-like 
member thus constructed is provided with an annular bead-like enlargement 
or with circumferentially spaced bead-like enlargements near the free 
axial end thereof which are adapted to engage by snap-action into a 
circumferential groove provided in the outer surface of the female 
coupling member so as to fasten the cap-like member rotatably with respect 
to the female coupling member in a readily detachable manner. 
Since the cap-like member with its inwardly projecting actuating parts can 
be readily made by any known process using plastic materials, such as 
suitable molding processes with the use of appropriate synthetic resinous 
materials, since the female coupling member only requires two recesses, 
milled-in at substantially right angle by simple machining operations, and 
since the locking arrangement basically includes only three parts; namely, 
the substantially flat sheet-metal latching member, the coil spring, and 
the cap-like member, ease of manufacture of the locking arrangement is 
assured by the present invention. Furthermore, since the sheet-metal 
latching member is merely loosely placed into the milled-out recess and 
since the coil spring is merely loosely placed against the back side of 
the sheet-metal latching member and can be manually compressed when the 
cap-like member is slipped over the same which itself is fastened by 
snap-in action, ease of assembly is also assured by the locking 
arrangement according to the present invention. 
To use a female coupling member with the same external dimensions for male 
connecting members of larger size couplings, it is only necessary in the 
arrangement of the present invention to replace the flat sheet-metal 
latching member of generally planar configuration with a flat sheet-metal 
latching member of approximately L-shaped configuration and to omit one 
inwardly projecting entrainment member so as to permit displacement of the 
locking or latching member away from the axis of the coupling to thereby 
accommodate larger size connecting nipples with the remainder of the 
external dimensions of the parts remaining the same. In practice, 
cross-sectional area ratios greater than 2:1 can be accommodated with 
female coupling members having the same external configuration by the use 
of the locking arrangement in accordance with the present invention. 
Still another feature of the present invention resides in a locking 
arrangement for a coupling in which the female coupling member is normally 
closed by a valve structure until the connecting nipple is inserted into 
place. The ever-increasing costs of energy require an energy consciousness 
not only as regards manufacturing costs, but also as regards energy-saving 
performance of such product in actual operation. The locking arrangement 
of the present invention which avoids unnecessary losses in the pressure 
lines, satisfies these requirements in an excellent manner.

Referring now to the drawing wherein like reference numerals are used 
throughout the various views to designate like parts, reference numeral 10 
generally designates therein a two-partite female coupling member 
consisting of a left coupling part 11 and of a right coupling part 12 
which are threadably secured together by the internally threaded portion 
provided in the external sleeve-like extension 13 of left coupling part 11 
and the externally threaded portion of the sleeve-like extension 17 of 
right coupling part 12. The left coupling part 11 is provided with an 
internal bore 14, the diameter of which is related to the size of the male 
coupling member or connecting nipple it can accommodate. Bore 14 in the 
coupling part 11 is connected with the reduced bore section 15 by way of 
the tapered bore section 16. The right coupling part 12 is provided with a 
threaded connecting bore 18 for connection with the pressure line and 
leads to chamber 20 formed within extension 17 by way of bore 19 of 
reduced diameter. As can be seen best in FIG. 2, the coupling part 11 is 
also provided with two recesses 23a and 23b milled in at right angle into 
the coupling part 11, of which the milled-in recess 23a intersects with 
its imaginary chord the internal bore 14, i.e., breaks through the wall of 
the coupling part 11 to provide a direct communication between the inside 
of the bore 14 and the milled-out recess 23a. Additionally, the left 
coupling part 11 is provided with an annular groove 25 for purposes to be 
explained hereinafter. 
The male coupling member or connecting nipple generally designated by 
reference numeral 30 is provided with an internal bore 31 for conducting 
therethrough the medium under pressure and includes a first portion 32 of 
larger diametric dimensions which terminates in an end portion of reduced 
diametric dimension 33 by way of a tapered section 34. Additionally, the 
male coupling member 30 is provided with a circumferentially extending 
groove 35 at such location that it will be in substantial axial alignment 
with the milled-in recess 23a when the connecting nipple 30 is in its 
engaged position. The circumferentially extending groove 35, as can be 
seen best in FIG. 1, forms a substantially right angle between its forward 
end surface and bottom surface of the groove 35 while its rear end surface 
passes over into the bottom surface by way of a rounded-off portion 35a. 
To keep the pressure line (not shown), which is normally connected with the 
female coupling member 10, closed when no connecting nipple 30 is inserted 
and thereby avoid energy losses, a valve member generally designated by 
reference numeral 40 is provided within the chamber 18 which is urged into 
its closing position by spring 41 in such a manner that the annular 
sealing surfaces 42 thereof engage the gasket 43 suitably seated in a 
corresponding recess provided in the female coupling part 11. An annular 
actuating disk 44 integral with the valve structure 40, for example, by 
way of support ribs 45, is adapted to be engaged by the free end face of 
the connecting nipple 30 when the latter is inserted into the bore 14 of 
the left coupling part 11 so as to open the valve structure 40 when the 
connecting nipple 30 reaches its engaged, locked position. 
The locking arrangement in accordance with the present invention basically 
involves only three parts; namely, the locking or latching member 50 (FIG. 
3) which is made from flat sheet-metal material and is basically 
rectangular, a coil spring 53, and a cap-like member generally designated 
by reference numeral 55 made of any suitable plastic material. For ease of 
assembly of the male connecting member 30 with the female coupling part 
10, the locking member 50 is provided with an approximately V-shaped notch 
51 in its rear end face, as viewed in the inserting direction of the 
connecting nipple, while its opposite forward end face is provided with a 
flattened, approximately U-shaped cutout 52 to assure secure locking of 
the parts 10 and 30. 
Two inwardly projecting entrainment members 56a and 56b as also a bead-like 
annular enlargement or spaced enlargements 57 are formed in one piece with 
the cap-like member 55 by being molded integrally therewith. The serrated 
or knurled external configuration 59 of the cap-like member 55 is also 
readily feasible by the use of an appropriate mold. 
For purposes of assembly, it is only necessary to place the locking or 
latching member 50 loosely into the milled-out recess 23a, then place the 
spring 53 loosely against the back surface of the latching member 50 and 
thereafter compress the spring 53, for example, with the thumb, while the 
cap-like member 55 is slipped over the outside surfaces of the left 
coupling part 11 until its bead-like enlargement 57 snaps into the annular 
groove 25, thereby securely fastening the cap-like member 55 in a readily 
detachable manner to the left coupling part 11. 
The parts of the coupling are shown in the locked, connected condition in 
FIGS. 1 and 2 in which the spring-loaded locking member 50 engages 
securely in annular groove 35. In order to disengage the connecting nipple 
30, it is only necessary to rotate the cap-like member 55 in the 
counterclockwise direction as viewed in FIG. 2, in which case the 
entrainment member 56a engages with the left free end of the locking 
member 50, lifting it out of the groove 35 against the force of spring 53 
and therewith enabling disconnection of the connecting nipple 30. With 
appropriate selection of the type of material and thickness, the 
entrainment member 56b may function as elastic abutment during rotation of 
the cap-like member 55 in the clockwise direction and additionally assumes 
the function of entrainment member when the entrainment member 56a is 
omitted with a larger connecting nipple as shown in FIGS. 4 and 5, in 
which case a locking or latching member 50' made of flat sheet-metal 
material and bent into approximately L-shape is used, as shown in FIGS. 5 
and 6. In that case, counterclockwise rotation of the cap-like member 55 
will cause engagement of the entrainment member 56b with the free end of 
the short leg 54 of the L-shaped latching member 50', causing the same to 
lift out of the annular groove 35 to permit disconnection of the 
connecting nipple 30. 
As to the rest, the embodiment of FIGS. 4-6 is similar to that of FIGS. 1-3 
and operates in the same manner. Both locking members 50 and 50' are made 
from flat sheet-metal stock by simple punching-out or stamping-out 
operations providing also notches 51 and cutouts 52. Moreover, as can be 
readily recognized, the external dimensions of the female coupling member 
10 of FIGS. 4 and 5 can be kept the same as in FIGS. 1 and 2 as also the 
dimensions of the cap-like member 55 thereof except for the elimination of 
one of its entrainment members. Standardization is also possible insofar 
as spring 53 is concerned. 
It is readily apparent from the foregoing that the locking arrangement in 
accordance with the present invention is extremely simple to manufacture 
and to assemble. Additionally, the locking arrangement according to the 
present invention permits ready accommodation of connecting nipples of 
different diameters over a relatively wide cross-sectional area ratio 
exceeding the ratio of 2:1. Furthermore, standardization of the parts is 
far-reachingly possible. Finally, by using plastics material of different 
color, readily realized by different color additives to the same basic 
material, the use of the coupling can be made easily recognizable, e.g., 
blue for compressed air, red for oxygen, etc. 
While I have shown and described only two embodiments in accordance with 
the present invention, it is understood that the same is not limited 
thereto but is susceptible of numerous changes and modifications as known 
to those skilled in the art, and I therefore do not wish to be limited to 
the details shown and described herein but intend to cover all such 
changes and modifications as are encompassed by the scope of the appended 
claims.