Coupling for pressure gas lines

A coupling for lines carrying gas under pressure in which a tubularly shaped male member is adapted to be inserted into a bore of a sleeve-like female member containing a valve assembly automatically opened upon insertion of the tubularly shaped male member. The tubularly shaped male member which is provided with an annular groove is held in its inserted position by a locking mechanism in the sleeve-like female member which consists of a latching member, a ring-like member surrounding the sleeve-like female member and a spring between the latching member and the ring-like member. For purposes of releasing the locking action of the latching member which is operable to engage in the annular groove by movement in a milled-in recess, the ring-like member is provided with an inwardly projecting actuating element. To permit a reduction in the dimensions of the ring-like member, the latching member includes a short leg portion bent with respect to the main portion of the latching member at such angle as to point toward the actuating member.

The present invention relates to a coupling for pressure gas lines which 
consists of two members adapted to be detachably connected one within the 
other in order to extend the line and thus enable the further conduction 
of the pressure gas. 
Many types of couplings are known in the prior art. My prior U.S. Pat. Nos. 
2,722,399; 2,795,438 and 3,174,774 are representative of some of my 
couplings which have proved successful heretofore. In another commercially 
successful construction of a coupling of this type which has been sold in 
large quantities and proved very satisfactory from an operational 
reliability, the latching member is constructed as cylindrical segment and 
is retained in the engaging position by means of a ring spring. The 
disengagement of the latching member takes place by means of an outer ring 
which is provided internally with a cam, connected with the ring from the 
outside by means of a screw. 
The disadvantages of this last-mentioned coupling construction are as 
follows: 
(1) The ring spring is difficult to install and may fatigue in the course 
of time. 
(2) The cylindrical segment requires a relatively large amount of space so 
that a large outer diameter results for the coupling. 
(3) A cylindrical segment is relatively complicated to manufacture because 
it requires machining and milling and therefore represents a machined part 
which is rather expensive. 
(4) The fastening of the inwardly projecting cam at the outer ring from the 
outside by means of a screw is also a complicated assembly operation and 
therefore relatively expensive. 
(5) The danger always exists that the screw will become loose in due 
course. 
(6) The cam itself is also relatively complex and expensive. 
To obviate these drawbacks, my prior U.S. Pat. No. 4,357,037 proposed a new 
approach which significantly reduced the costs involved in the manufacture 
and assembly of the couplings of this type. However, the coupling 
disclosed in my prior U.S. Pat. No. 4,357,037 which consisted of a 
rotatable cap-like member provided with an inwardly projecting entrainment 
member adapted to engage with a latching member made from flat sheet metal 
material, did not yet permit a reduction in the outside dimensions of the 
coupling. Such reduction in outside dimensions, without loss in 
through-flow capacity, becomes important, particularly for all-metal 
constructions as desired by some customers. 
Accordingly, it is the principal object of the present invention to provide 
a coupling of the type described above which assures low cost in 
manufacture and assembly, a reduction in outside dimensions and reliable 
operation without loss of through-flow capacity of the coupling. 
The underlying problems are solved according to the present invention in 
that, differing from my prior U.S. Pat. No. 4,357,037, the latching member 
which is punched or stamped-out from flat plate material, is bent with its 
shorter leg portion from its original position at an acute angle pointing 
toward the inwardly projecting actuating member which, in the case of an 
all-metal construction, is a rivet secured to the ring member. As a result 
of this particular configuration of the latching member, in which the 
shorter leg portion is bent in the direction toward the inwardly 
projecting actuating member, the actuating member seeks to displace the 
latching member in the direction of the shorter leg portion during 
rotation of the ring member in the disengaging direction. This, in turn, 
permits the diametric dimensions of the ring member to be significantly 
reduced since the opening movement of the latching member against the 
spring force which takes place in a more or less pivot-like manner about 
the free end of the main portion of the latching member, now takes place 
in the direction of the shorter leg portion. 
A coupling made in accordance with the present invention permits a 
reduction of the maximum outer diameter thereof by about 25%, a reduction 
in weight of about 30% and a reduction in manufacturing costs of about 30% 
when the coupling is made completely of metal parts. 
In a particularly advantageous construction according to the present 
invention, the inwardly projecting actuating member is secured to the ring 
member from the outside by a so-called pop rivet which, in addition to the 
function as actuating member, then also secures the ring on the housing of 
the coupling so as to prevent it from falling off. This type of 
manufacture offers the significant advantage that an extraordinarily rapid 
assembly is made possible and the coupling cannot be disassembled by 
unauthorized persons. On the other hand, any disassembly necessary for 
repairs is extraordinarily simple for the manufacturer of these couplings 
because the pop rivet can be simply bored-out and then be replaced with a 
new once, once the repair is completed. Even under strongest vibrations, 
these pop rivets cannot become loose, thereby eliminating any accident 
danger. 
If the present invention is applied to a coupling with a plastic cap-like 
member as disclosed in my prior U.S. Pat. No. 4,357,037, the advantages of 
smaller outside dimension and reductions in weight on the part of the 
housing can also be achieved. However, in that case, the inwardly 
projecting integrally molded actuating member is provided with an 
actuating surface disposed at such an angle as to be substantially 
parallel to the flat end face of the shorter leg of the latching member. 
This will also assure an actuation of the latching member substantially in 
the direction of the shorter leg thereof when the cap-like ring member is 
rotated in the disengaging direction.

Referring now to the drawing, wherein like reference numerals are used 
throughout the various views to designate like parts, and more 
particularly to FIGS. 1-4, the coupling in accordance with the present 
invention is composed of a two-partite sleeve-like member generally 
designated by reference numeral 10 which forms the female coupling part, 
and of a tubularly shaped member generally designated by reference numeral 
30 which forms the male coupling part and is in the form of a nipple or 
the like. The two-partite sleeve-like member 10 includes a right 
sleeve-like coupling part 11 containing a normally closed valve assembly 
generally designated by reference numeral 40 and screwed together with the 
left sleeve-like coupling part 12 at 13. The right sleeve-like part 11 is 
provided with a threaded connecting bore 14 or the like for connection 
with the pressure line (not shown) carrying pressure gas. The internal 
bore 14 is connected by way of a bore 16 of reduced dimension with an 
internal chamber 15 containing the valve assembly 40. 
The left sleeve-like coupling member 12 is provided with an internal bore 
18, the diameter of which is related to the outer diameter of the 
tubularly shaped male member 30. The bore 18 is connected by way of a 
tapering section with a short bore section 29 of reduced diametric 
dimensions which leads into the chamber 15. 
As can be best seen in FIG. 2, the left coupling part 12 is provided with 
two milled-out recesses 20 and 21 disposed at right angle to one another, 
of which the milled-out recess 20 intersects with the internal bore 18 to 
provide a direct communication between the inside of the bore 18 and the 
milled-out recess 20. 
The tubularly shaped male coupling member 30 is provided with an internal 
bore 31 for conducting therethrough the pressure gas, once the valve 40 is 
opened when the tubularly shaped male coupling member 30 is inserted into 
and locked-in within the sleeve-like coupling member 10. The tubularly 
shaped male coupling member 30 which may be of any conventional 
construction for connection with a pressure line extension, includes a 
first portion 32 of a diametric dimension complementary to the dimension 
of the internal bore 18 and a second diametric portion 33 of reduced 
diametric dimension, complementary to the internal bore 29. Additionally, 
the tubularly shaped 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-out recess 20 when the 
tubularly shaped male coupling member 30 is in its engaged position within 
the sleeve-like coupling member 10. To avoid energy losses, when no 
connecting nipple 30 is inserted into the sleeve-like coupling member 10, 
the valve assembly generally designated by reference numeral 40 is urged 
into its closing position by a spring 41 in such a manner that the annular 
sealing surfaces 42 thereof engage the gasket or packing 43 suitably 
seated in a corresponding recess provided in the sleeve-like female 
coupling part 12. An annular actuating disk 44 which is integral with the 
remaining valve structure 40, for example, by way of ribs 45 is adapted to 
be engaged by the free end face of the tubularly shaped male coupling part 
30 when the latter is inserted into the bore 18 so as to open the valve 
structure 40 when the tubularly shaped male coupling part 30 reaches its 
engaged, locked position. 
As disclosed in my prior U.S. Pat. No. 4,357,037, the locking arrangement 
in accordance with the present invention basically involves also only 
three parts; namely, a latching member generally designated by reference 
numeral 50 (FIGS. 3 and 4), a coil spring 53 (FIGS. 1 and 2) and a ring 
member generally designated by reference numeral 55 which is provided with 
an inwardly projecting actuating element generally designated by reference 
numeral 58. Except for dimensions and certain details to be described more 
fully hereinafter, the coupling so far described is similar to that 
disclosed in my prior U.S. Pat. No. 4,357,037. 
Differing from my prior U.S. Pat. No. 4,357,037, the latching member 50 
which is again punched or stamped-out out of flat material, consists of a 
flat main portion 51 and of a shorter leg portion 52 which is bent at an 
angle .alpha. (FIG. 3) with respect to the original position corresponding 
to the plane in which the main flat portion 51 lies in such a manner that 
it points toward the inwardly projecting actuating element 58. The angle 
.alpha. may be of the order of 60.degree. to 80.degree., in the 
illustrated embodiment, is about 75.degree.. By bending the shorter leg 
portion 52 in the manner shown in FIGS. 2 and 3, it is possible to reduce 
the overall diametric dimension of the coupling, particularly insofar as 
it relates to the diametric dimensions of the ring member 55. This is 
important with an all-metal construction in which savings in weight and 
material are an important factor. 
In the embodiment illustrated in FIGS. 1-4, the ring member 55 is rotatable 
on the end portion 19 of the left sleeve-like coupling part 12, which is 
of such reduced diametric dimension that the outer surface of the ring 
member 55 is substantially flush with the outer surfaces of the 
sleeve-like coupling member 10. These reduced dimensions of the coupling 
are possible in accordance with the present invention since rotation of 
the ring member 55 in the disengaging direction (counterclockwise rotation 
in FIG. 2) will cause the latching member 50 to more or less pivot about 
the free end of the main portion 51 by displacement of the shorter leg 
portion 52 at least approximately parallelly to itself through the gap 
formed between the internal surface of the ring member 55 and the 
90.degree. intersection of the milled-in recesses 20 and 21. In other 
words, in the disengaging movement of the latching member 50, the shorter 
leg portion 52 is displaced generally in its own direction, as indicated 
by angle .alpha., when actuated by actuating member 58. 
In a preferred embodiment of an all-metal construction in accordance with 
the present invention, the inwardly projecting actuating member 58 is 
realized by the use of a commercially available so-called pop rivet (FIG. 
5A) which consists of a stem portion 59 having an enlarged head 60 and of 
a sleeve 61 surrounding the stem portion 59 and including a flange 62 of a 
diameter greater than the hole in the ring member 55, into which the rivet 
is inserted. When the flange 62 is applied against the outside of the ring 
member 55 while the stem 59 is pulled out, the enlarged head 60 forces the 
sleeve 61 to bulge outwardly along the inside of the ring member 55 until 
the stem 59 breaks. The stem 59 may be provided with reduced portions, as 
shown in FIG. 5A, to facilitate breaking when the sleeve 61 is enlarged 
into the more or less spherical configuration 61a as shown in FIG. 5B. 
The thus-installed rivet 58 not only serves as actuating member for 
displacing the shorter leg portion 52 generally in its own direction, but 
additionally secures the ring member 55 against falling off the reduced 
diametric portion 19. Additionally, it prevents disassembly by 
unauthorized personnel, yet permits such disassembly by the manufacturer 
in case of needed repairs, by merely boring out the rivet 58, whereupon 
the ring member 55 can be slipped off the reduced diametric portion 19 and 
the remaining parts of the locking mechanism can be disassembled. 
The coupling in accordance with the present invention is not only easy to 
manufacture accompanied by savings in material and weight, but is also 
easy to assemble. The valve structure 40 is assembled within chamber 15 in 
a conventional manner. With respect to the locking mechanism, it is only 
necessary to insert the latching member 50 into the milled-out recess 20, 
mount the spring 53 over the outside of the main portion 51 and then slip 
the ring member 55 over the reduced diametric portion 19 while compressing 
the spring 53. Thereafter, the pop rivet is installed by slipping the 
non-deformed rivet into the position shown in FIG. 5A and thereafter 
deforming the rivet as shown in FIG. 5B. 
The present invention which enables reduced diametric dimensions, is also 
applicable to a coupling in which the ring member 55 of FIGS. 1 and 2 is 
replaced by a plastic cap-like ring member 155 as shown in FIGS. 6 and 7 
in which similar parts are designated by corresponding reference numerals 
of the 100 series. As can be seen in particular in FIG. 7, the inwardly 
projecting actuating member generally designated by reference numeral 158 
which is molded integrally with the cap-like ring member 155 made of 
plastic material, includes an inclined actuating surface 158a 
substantially parallel to the end face of the shorter leg portion 152 to 
assure actuation of the latter by displacement thereof generally in its 
own direction. 
The cap-like member 155 can be retained on the portion 119 of reduced 
diametric dimension in the manner described in my prior U.S. Pat. No. 
4,357,037 by the use of a bead-like enlargement 157 which snaps into the 
annular groove 125 and/or by the use of a clip ring or snap ring (not 
shown). 
Thus, the present invention assures by extremely simple means considerable 
savings in labor and material both in the manufacture and assembly of the 
coupling, permits a reduction in outside dimensions without reduction in 
through-flow capacity and provides for a competitively priced all-metal 
construction which is reliable in operation. 
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.