Coupling
[451 Apr. 15, 197s United States Patent Kraus et al.  
 PATENTEUAPR 5ms snm 1 gf if,  
 PATENTEUAPR 1 51975 SHEET 3 ur 3 coUPLlNG BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to a coupling.  
 2. Description of Prior Art Many quick-disconnect couplings have been devised in the past` yet none has met all the criteria for a completely satisfactory device of this type. Many quickdisconnect couplings use sleeves which are slid axially when the coupling is mated and unmated for activating the coupling mechanism. These devices are relatively complicated and expensive, involving springs and a substantial number of parts. The two coupling sections are different in these designs` so that they must be mated properly when the coupling is secured. Other quick-disconnect couplings have involved rotation through a partial turn in connecting and disconnecting the mating parts. Typically&#39;, this involves projecting L- shaped lugs which are to interengage when the two coupling parts are mated. The lugs of these couplings are vulnerable to damage and, when bent, will prevent the coupling from functioning. Such couplings are relatively expensive in that they must be machined from metal` not being adapted for molded construction out of plastic. Sealing is complicated with these couplings and overtravel normally is required in the functioning of the detent as the parts are moved axially&#39; beyond their ultimate mated position during the coupling operation. When fully mated, the exterior of the coupling is not smooth, resulting in spaces between the lugs which can accumulate dirt and prevent release of the coupling. Many couplings of the prior art do not provide a smooth inside joint when the coupling is mated, and may produce a severe restriction. resulting in resistance to the flow of fluid. Partial turn couplings. such as shown in U.S. Pat. No. 99,7l5 and 103,785. have relatively moving parts on each section. with attendant cost and difficulty of operation.  
 SUMMARY OF THE INVENTION The present invention provides an improved lowcost` universal` quick-disconnect coupling overcoming all the shortcomings of the prior designs. It is adapted for molding from plastic and is of durable and rugged construction. When mated, it presents a completely smooth exterior surface so that dirt and foreign matter cannot accumulate in any location. Its interior also is smooth and of large diameter. so that it affords almost no additional resistance to fluid flow.  
  The coupling includes two identical sections, so that there is never a problem in selecting the proper coupling components for mating. Each section includes both inside and outside threads. preferably a dual-lead thread in both instances, with the inside threads being positioned intermediate the outside threads. Full meshing is accomplished by only a quarter turn of relative rotation` with no axial overtravel. Tabs project forwardly&#39; from the end of the coupling member at the entrances to the outside threads, the member provided with axial recesses intermediate the tabs for receiving the tabs of the mating component. The tabs provide a convenient means to guide the coupling sections together so that they can be rotated to the fully mated position in which the inside and outside threads of the two members are meshed. They also act as stops upon reverse rotation of the coupling components prior to &#39;cli their rotation to the mated position. The tabs also may incorporate a detent, which may be in the form of a ridge on the exterior of the tab to mate with a groove formed in the circumferential wall of the recess.  
  The seal for the coupling is on an annular surface which is inside the threads and the tab elements. This surface may have a groove in which is received an O- ring so that the O-rings of the two mating coupling components abut and prevent fluid leakage. An alternate form of seal is an integral lip which projects from the radial surface and is inclined inwardly. The lips are deflectable so that they can maintain firm engagement on their outer surfaces when the coupling is mated. By virtue of their inward inclination, the lips can be reacted upon by fluid pressure to increase the force with which they bear against each other, thereby enhancing the sealing effect.  
  A hose may be bonded to the opposite end of the coupling member, being received in a counterbore so that the coupling has a smooth interior surface. For another connection to a hose, the member may be provided with an axial recess to receive the hose` the inner wall of the recess having an annular groove allowing the coupling member to be softened by a heated tool and deflected inwardly&#39; so as to force the wall of the hose into the annular groove and lock the hose to the coupling.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the components of the coupling of this invention. separated from each other;  
  FIG. 2 is an end elevational view of one of the coupling members;  
  FIGS. 3, 4 and 5 are enlarged fragmentary sectional views taken along lines 3--3, 4-4 and 5 5, respectively, of FIG. 2;  
  FIG. 6 is a fragmentary side elevational view. partially broken away, of the coupling with its two components held together. but prior to rotation to the mated position;  
  FIG. 7 is a fragmentary side elevational view, partially broken away. of the coupling in the mated position;  
  FIG. 8 is a transverse sectional view taken along line 8-8 of FIG. 6;  
  FIG. 9 is a transverse sectional view taken along line 9-9 of FIG. 7;  
  FIG. 10 is a longitudinal section view of the mated coupling taken along line 10-10 of FIG. 9;  
  FIG. ll is a fragmentary side elevational view of the coupling members angularly positioned for rotation to the mated position, but shown separated from each other for purposes of illustration.  
  FIG. l2 is a fragmentary side elevational view similar to FIG. ll, but with the coupling components angularly positioned as in a mated condition;  
  FIG. I3 is a side elevational view of the mated coupling;  
  FIG. 14 is an enlarged fragmentary sectional view showing an alternate seal,  
  FIG. lS is an enlarged fragmentary sectional view showing the seal of FIG. 14 with the coupling mated:  
  FIG. 16 is an enlarged fragmentary longitudinal sectional view of the coupling embodying a different means for attachment to the hose, shown in the process of securing the hose to the coupling; and  
  FIG. 17 is a view similar to FIG. 16, but with the hose secured to the coupling.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT The coupling of this invention consists of two identical tubular members l0, used to interconnect the ends of hoses 1l and 12 in the example shown. The members l may be made of plastic having resilience and a relatively high strength, such as that marketed by General Electric Company under the trademark LEXAN and the plastic marketed by E. I. duPont deNemours and Company under the trademark DELRIN. Each member 10 includes a central opening 13 of circular cross section interconnecting the rearward end 14 and the forward end where the elements of the locking mechanism are located. A counterbore l extends inwardly from the rearward end 14, defining a radial shoulder 16 at its inner end (see FIG. The ends of the hoses l1 and 12 fit into the counterbores l5 of the two members 10, with the hose ends abutting the shouldersl. The periphery&#39; of the hose is bonded to the surface of the coupling member l0 within the counterbore. The wall thickness of the hose approximates the width of the shoulder I6, so that the inner surface of the hose is substantially&#39; flush with the surface of the bore 13 beyond the hose.  
  At their forward ends, the coupling members 10 include both inside and outside threads which form inclined planes. There are two identical inside threads 18 and 19, which commence at diametrically opposed longitudinal shoulders 20 and 2l, and extend -through arcs of 90. Similarly&#39;, there are two outside threads 22 and 23 that are diametrically opposite and are 90 segments. The longitudinal shoulders 24 and 25 at the entrances to the outside threads 22 and 23, respectively, are spaced midway between the shoulders 20 and 21. The threads 18, 19, 22 and 23 are square in shape and are on similar helices.  
 The flanks` of the inside threads 18 and 19 formed by their axially outer surfaces 26 and 27, respectively, extend radially to the outer peripheral surface 28 of the member 10. Axially inwardly and at the root of the in-y side thread 18 is an inside surface 29 w&#39;hich is a fragment of a cylinder and provides the member l0 with a relatively thin wall at that location. A similar surface 30 is located axially inwardly of the thread 19. The surfaces 29 and 30 have substantially the same diameter as the crests of the outside threads 22 and 23.`  
  The outer surface 26 of the inside thread 18 continues in the same helix beyond the inner end of the thread at the shoulder 25, extending beneath and parallel to the outside thread 23. In a like manner, the surface 27 of the inside thread 19 has a continuation beneath the outside thread 22. The extensions of the surfaces 26 and 27 terminate at the shoulders 2l and 20, respectively, and with the adjacent outside threads define helical grooves. In other words, the continuation of the surface beyond the outer surface of one inside thread extends through an additional arc of 90 to the angular location where the other inside thread begins.  
 The axially outer surface 32 ofthe outside thread 22 ism with the inside thread 18. The surface 32, including its continuation, describes a total arc of 180 and has its inner end at the shoulder 25. On the opposite side of the member 10, the axially&#39; outer surface33 of the V outside thread 23 has a similar extension beneath the inside thread 19, terminating at the shoulder 24.Thus` each outside thread has an outer surface which continues beneath an inside thread and ends at the angular location where the other outside thread starts. The sur faces 26 and 27 are spaced from the outside threads 23 and 22, respectively, a distance equal to the thickness of the inside threads 18 and 19. This is the same dis-` tance as that between the surfaces 32 and 33 and the inside threads-18 and 19, and corresponds to the thic&#39;kness of the outside threads 22 and 23.  
  The outside surfaces 26, 27, 32 and 33 of the threads are all flat and perpendicular to the longitudinal axis of the member 10. The outer ends ofthe threads. both inside and outside, fall in the same plane, which is radial with respect to the coupling member 10. With the helices of the threads being similar and their arcs the inner ends of thethreads likewise are in the same radial plane.  
 Projecting axially forwardly&#34; from the coupling ele-k ment 10 are two diametrically opposed tabsy 34 and 35 which are shaped as cylindrical segments. The tabs 34 and 35 are positioned at the beginning of the outside threads 22 and 23, respectively, and extend angularly inwardly a short distance with `respect to these threads. Hence, the forward edge of the tab 34 is formed bythe shoulder 24 that also forms the outer end of the outside thread 22. The shoulder 25 Provides the forward edge of the other tab 35. The rearward edges 37 and 381of the tabs 34 and 35, respectively&#39;, are parallel to the edges provided by the shoulders 24 and 25.  
 Intermediate the tabs 34 and 35 are relatively deepl inwardly&#39; to the end walls 41 and 42 of the recesses 39 and 40, respectively, and act as one end for each recess. The other ends of the recesses 39 and 40 `are formed by extensions of the tab edges 37 and 38,y re-y spectively.  
 A flat radial` surface 47 interconnectsthe central V bore 13 of the coupling member 10 and the recesses 39 and 40. An annular groove 48 in the midpart of the sur-` face 47 receives an O-ring 49, which projects above this surface and acts as a seal when the coupling is se` cured. The surface 47 is in a plane within which also falls the surfaces 26 and 27 at the locations of the inner ends of the outside threads 22 and 23. The surfaces 32 and 33 at the inner ends of the inside threads 18 and 19 are also in this plane.  
  Prior to securing the coupling` the entrances to the inside threads of one coupling unit l0 are placed adjacent to the entrances to the outside threads of the other.  
 coupling unit 10. In the example of FIGS. 6 and 8, the  
 entrance to the inside. thread 18 of the coupling unit 10 on the left is adjacent the yentrance to the outside, .y  
 thread 23 of the` other coupling unit on the right. Also, the entrancerto the inside thread 19 of the latter cou.-  
 pling unit l0 can be seen next to the entrance to the l outside threadof the coupling unit 10 located to the left in this view. In this position, the outer surfaces of the inside threads are brought into engagement with each other and. similarly, the outer surfaces of the outside threads are pressed together. As illustrated in FIG. 6, the surfaces 26 and 27 of one coupling unit l0 engage the surfaces 26 and 27, respectively, of the other. This brings the outer surface 32 of the coupling unit l0 shown on the left into engagement with the outer flank surface 33 of the outside thread 23 of the other coupling section l0 shown on the right. When this is done. the tab 34 of each coupling section l0 enters the recesses 40 of the other coupling section l0. Similarly. the tab 35 of each coupling section received in the recess 39 of the other section. These tabs. by fitting within the recesses` help guide in two coupling sections to assume an axially aligned position.  
  The coupling is most easily prepared for rotation to the secured position by first being given reverse rotation as the two sections are pushed together, so that the rearward edges of the tabs are in abutment. With the parts assembled in the manner shown in FIGS. 6 and 8, this brings the rearward edges 37 of the tabs 34 into contact with the rearward edges 38 of the tabs 35. The tabs are proportioned such that, when the rearward edges are so in engagement` there is a small gap between the entrances of the threads that are to be meshed when the coupling is mated.  
  With the end faces of the coupling sections held together` they are then rotated relative to each other for just over a quarter turn, bringing the coupling to its full)l mated position, as shown in FIGS. 7 and 9. (For purposes of illustration, the left-hand coupling section I0 is shown in the same position in FIGS. 6-9, while the right-hand coupling section l0 is rotated in mating the coupling.) The outside thread 22 of the left-hand coupling section l0 meshes with the inside thread 19 of the coupling section positioned to the right, while the outside thread 23 ofthe left coupling section meshes with the inside thread 18 of the other. The rotation brings the shoulders at the entrances to the outside threads and the forward edges of the tabs into abutment. That is to say` the shoulders of the two coupling halves are brought into interengagement, as are the shoulders 24. Also, the shoulders 20 at the outer ends of the inside threads 18 are engaged by the shoulders 21 at the entrances to the inside threads 19 when the two coupling halves are brought into interengagement by being rotated from the position of FIGS. 6 and 8 to that of FIGS. 7 and 9. The inside threads enter the helical grooves formed by the outside threads and the extensions of the flank surfaces 26 and 27 of the inside threads. The outer flank surfaces 26 and 27 of one coupling section 10 engage the continuations of the flank surfaces 26 and 27 of the other coupling section when the coupling is mated. As a result of this, the coupling is entirely closed off from the outside when mated, leaving no gaps or openings. The entire lengths of the threads are in engagement and concealed, protected from any injury when the coupling is secured. The long area of thread engagement gives strength to the assembled coupling.  
  When the coupling is mated, the radial surfaces 47 of the two sections are brought into adjacency. This causes the O-rings 49 to press against each other and form an effective seal. The inside of the mated coupling is smooth, with no restrictions to the free flow of fluid. The full diameter of the hoses ll and l2 is maintained throughout the length of the coupling.  
  Rotation of the coupling members 10 in mating and separating the coupling is facilitated by longitudinal grooves 50 in the outer surface 28 of each coupling member. These grooves allow the coupling members to be gripped more securely, and have the added advantage of conserving material.  
  A detent is provided to hold the parts in the mated position. The detent may be simply longitudinal ridges 51 and 52 on the two tabs 34 and 35, which are adapted to enter complementary longitudinal grooves 53 and 54 in the outer circumferential walls 44 and 46 of the recesses 39 and 40. When the tabs 34 and 35 enter the recesses 39 and 40, the ridges 51 and 52 slide along the outer circumferential surfaces 44 and 46, deflecting the tabs 34 and 35 slightly inwardly. When the grooves 53 and 54 are reached, the tabs spring outwardly. forcing the ridges 51 and 52 into their mating grooves 53 and 54. Reverse rotation will release the detent by forcing the ridges 5l and 52 out ofthe grooves 53 and 54, again allowing the ridges 51 and 52 to slide along the circumferential surfaces of the recesses as the coupling sections are unthreaded.  
  Alternative to the O-ring seals 49, an integral seal may be provided on the end face 47, as shown in FIGS. 14 and l5. The integral seal is merely a lip 56 which is thin and deflectable, projecting outwardly from the outer edge of the surface 47 and curved so as to incline inwardly. When the two lips 56 are in engagement. they form a seal. and the fluid pressure within the coupling bearing against the inner surfaces of the sealing lips 56 urges them more tightly together to enhance the sealing effect. The radial surfaces 47 are recessed axially a short distance when the integral seal is used, compared with the O-ring version, so that they are not quite as close together when the coupling is mated.  
  The hose may be attached to the coupling through the arrangement shown in FIGS. 16 and I7, rather than by bonding. ln this construction, the coupling includes an annular recess 57 at its rearward end, dimensioned to receive the wall of a hose 58, and may have a cylindrical outer surface 59 at that end. The annular recess 57 includes a circumferential groove 60 in its inner wall. With the hose 58 received in the recess 57, a suitable heated tool 61 is brought into engagement with the outer periphery 59 of the coupling in radial alignment with the groove 60, locally heating and softening the material of the coupling. The tool is pressed against the surface of the coupling to force the softened material inwardly toward the groove 60. When the material then cools, it has a slight groove 62 in its outer surface and is deflected inwardly at this location so as to force the hose into the groove 60, thereby locking the hose to the a second inside thread extending partway therearound from an entrance thereto at at a different location from said entrance to said first outside thread to an inner end thereof at a different location from said inner end of said first outside thread such that when said end portions of said members are brought into engagement and relatively rotated said first thread of each of said members meshes with said second thread of the other of said members so that said members assume a mated position` at least one of said first yand second threads of each of said members having a shoulder adjacent the entrance thereto. said shoulders of said members being opposite from each other and in adjacency&#39; when said members so assume said mated position. and sealing means.  
 said sealing means being in interengagement when said members are in said mated position. 2. A device as recited in claim l in which said end portions of said members are identical.  
 3. A device as recited in claim l in which said members are of plastic material.  
 4. A device as recited in claim 1 including in addition detent means for holding said members in said mated position.  
  5. A device as recited in claim&#39;l in which said outside thread and said inside thread of each `of said members are of substantially the same thickness.  
  6. A device as recited in claim l in which &#39;said outside thread is in at least two parts` and said inside thread is in at least two parts.  
 with said parts of said inside thread being intermediate said parts of said outside thread. 7. A device as recited in claim 6 in which said parts of said outside thread are diametrically opposed. and said parts of said inside thread are diametrically opposed.  
 8. A device as recited in claim 6 in which the entrances to said outside threads and said inside threads are in the same plane, which plane is radial with respect to said member.  
 9. A device as recited in claim 1 in which said outside thread is in two diametrically opposed parts. each of said parts of outside thread extending through an arc of substantially&#39; 90, and said inside thread is in two diametrically opposed parts. each of said parts of said inside thread extending through an arc of substantially 90, said parts of said inside thread being intermediate said parts of said outside thread. l0. A device as recited in claim 1 in which said outside thread has an axially outer flank surface extending to the entrance to said inside thread, said surface of said outside thread having a continuation thereof extending beyond said outside thread in parallelism with said inside thread to define a first helical groove, said inside thread has an axially&#39; outer flank surface extending to the entrance of said outside thread. said surface of said inside thread having a continuation thereof extending beyond said inside thread `in spaced parallelism with said outside threadt define a second helical groove,  
 and in which when said members assume said mated position said outside thread of each of saidmembers is received in said first helical groove ofthe other of said members, and said inside thread of each of said members is received in said second helical groove of the other of said members.  
 ll. A device as recited in claim l0 in which the axially&#39; outer flank surfaces of said inside and said outside threads fall in the same plane at diametrically. opposed locations. which plane is radial with respect to said member.  
 12. A device as recited in claim l0 in which. when said members are in said mated position.  
 each of said members has at least one tab extending axially outwardly&#39; of said end portion thereof. and: has a recess extending axially inwardly&#39; of said end` portion for receiving said tab of the other of said members. 14. A device as recited in claim 13 in which each of said members includes a duality of said tabs.  
 said tabs extending axially outwardly from the entrances to said outside threads.  
 and in which said recess of each of said members in-y cludes a dualityl of portions extending between said` tabs. said recess portions being shaped as cylindrical segments. l5. A device as recited in claim l4 in which said tabs are shaped as cylindrical segments.  
 16. A device as recited in claim 14 in which each of said tabs has a forward surface aligned with the entrance of said outside thread adjacent thereto, and a rearward surface opposite said forward surface. said members being positionable prior to said relative rotation to said mated position with said rearward surfaces of said tabs of one of said members abutting said rearward surfaces of said tabs of the other of said members` the entrance to said inside thread of each of said members being then adjacent but spaced angularly outwardly of the entrance to said outside f thread of the other of said members. 17. A device as recited in claim 13 including a detent for holding said members in said mated position,  
 said detent including cooperable protuberance and recess means,  
 one portion of which is on said tab and the other portion of which is on said member within said recess means. 18. A device as recited in claim 17 in&#39;which for said detent each of said tabs is provided with a longitudinal ridge thereon. and in which said member is provided with a longitudinal recess engageable by said ridge when said members are in said fully mated position.  
 19. A device as recited in claim l in which each of said members includes a substantiallyl radial surface radially inwardly of said threads. said sealing means projecting from said radial surface.  
  20. A device as recited in claim 19 in which said sealing means includes an O-ring, said radial surface having an annular groove therein receiving a portion of said O-ring.  
 21. A device as recited in claim l9 in which said sealing means includes an integral deflectable lip extending outwardly from said radial surface and inclined inwardly&#39; toward the axis of each of said members` whereby said lips can abut when said members are mated and fluid pressure can be exerted against said lips for urging the same into interengagement.  
  22. A device as recited in claim l in which at least one of said members has a counterbore in the opening therethrough at the opposite end portion thereof&#39;for receiving the end portion of a hose.  
 23. A device as recited in claim l in which each of said members includes an axially extending annular recess in the opposite end portion thereof adapted to receive the end portion of a hose,  
 said recess having an inner circumferential wall h and an outer circumferential wall.  
 said inner circumferential wall having groove means therein, whereby the end portion of such a hose can be deflected into said groove means upon inward deflection of said outer circumferential wall for thereby securing said hose to said member.  
  24. A device as recited in claim 23 in which said members are of heat softenable plastic material. whereby said outer circumferential wall can be so deflected inwardly upon the application of heat and pressure to the exterior of said member 25.&#39;A coupling device comprising a duality of members. l  
 each of said members including an end portion having a plurality of substantially identical outside threads. and a plurality of substantially identical inside threads` said inside and outside threads being fixed relative to each other with said inside threads being intermediate said outside threads, and having entrances positioned at different locations such that when said end portions of said members are brought into engagement and relatively rotated said outside threads of each of said members mesh with said inside threads of the other of said members so that said members assume a mated position.  
  26. A device as recited in claim 25 in which each of said members includes recess means in said end portion thereof.  
 and a projecting guide element for entry into said recess means ofthe other of said members for facilitating said movement of said members to said mated position.  
  27. A device as recited in claim 25 in which said threads of said members so mesh with each other substantially throughout the lengths thereof and provide thread meshing around the entire circumference of said members when said members so assume said mated position.  
  28. A device as recited in claim 25 in which said outside thread includes an axially&#39; inner surface having an extension which extends outwardly beyond said entrance to said outside thread and to a position adjacent said entrance to said inside thread.  
  29. A device as recited in claim 28 in which said inside thread includes an axially&#39; outer surface on a helix substantially parallel to the helix of said extension of said axially inner surface of said outside thread.  
  30. A device as recited in claim 29 in which said axially inner surface of said outside thread and said extension thereof are substantially perpendicular to the longitudinal axis of said thread.  
  31. A device as recited in claim 30 in which each of said members includes two of said outside threads and two of said inside threads, said entrances to said inside threads being intermediate said entrances to said outside threads.  
 32. A hermaphroditic coupling, which comprises:  
 a first coupling element adapted to be connected to one component to be coupled.  
 a second coupling element adapted to be connected to another component to be coupled, so that said components are connected to each other when said first and second coupling elements are interengaged, said first and second coupling elements having end portions substantially identical to each other, and a male thread section and a female thread section provided at said end portion of each of said coupling elements, each of said male and female thread sections of each of said coupling elements having an entrance and extending therefrom for only a fraction of one revolution,  
 said male thread section of each of said coupling elements extending from said entrance thereof to an inner end thereof in juxtaposition with said entrance to said female thread section thereof, said female thread section of each of said coupling elements extending from said entrance thereof to an inner end thereof in juxtaposition with said entrance to said male thread section thereof, said male thread section of each of said coupling elements being at a circumferential position different from that of said female thread section of the same coupling element,  
 said male thread section of said first coupling element being complementary to and shaped to mate with said female thread section of said second coupling element.  
 said female thread section of said first coupling element being complementary to and shaped to mate with said male thread section of said second coupling element,  
 said male and female thread sections of both of said coupling elements being so located and shaped that when said end portions of said first and second coupling elements are in predetermined initial rotated positions relative to eachother` rotation of said first coupling element relative to said second coupling element through less than one revolution will cause said male thread section of said first coupling element to mesh with said female thread section of said second coupling element, and will also cause said female thread section of said first coupling element to mesh with said male thread section of said second coupling element, thereby interengaging and closing the coupling.  
  33. The invention as claimed in claim 32, in which each of said coupling elements has two of said male thread sections and two of said female thread sections. each of said thread sections extending for about onequarter revolution` said male and female thread sections of each of said coupling elements alternating with each other.  
  34. The invention as claimed in claim 32, wherein said male thread section on each coupling element is immovably fixed in position relative to said female thread section on the same coupling element.  
  35. The invention as claimed in claim 32, in which said thread sections are inclined relative to a plane which is perpendicular to the axis of the coupling,  
 whereby said relative rotation causes axial movement of said first coupling element relative to said second coupling element.  
  36. The invention as claimed in claim 35, in which said components to be coupled are fluid conduits, and in which seal means responsive to said axial movement are provided to prevent fluid leakage from the closed coupling.  
  37. A hermaphroditic thread coupling, which comprises:  
 a first coupling element adapted to be connected to one component to be coupled, and  
 a second coupling element adapted to be connected to another component to be coupled, so that said components are connected to each other when said first and second coupling elements are interengaged` said first and second coupling elements having end portions substantially identical to each other, each of said coupling elements having at said end portion thereof an inclined thread wall, said thread wall forming along onepart of its length the side wall of a male thread sections. and said thread wall forming along another part of its length the side wall ofa groove which is part of a female thread section.  
  38. The invention as claimed in claim 37, in which an end of said male thread section is adjacent an end of said female thread section.  
 39. A hermaphroditic coupling` which comprises:  
 a first coupling element adapted to be connected yto one component to be coupled, a second coupling element adapted to be connected to another component to be coupled, so that said t components are connected to each other when said t each of said inclined planes partially overlapping another of said inclined planes, one portion of each of said inclined plaines being a surface of a ridge of a male thread section,` another portion of each of said inclined planes defining a wall of a groove in a female thread section. 40. The invention as claimed in claim 39, in which one end region of each of said inclined planes overlaps another of said inclined planes, in which the other end` region of each of said inclined plane overlaps still another of said inclined planes, said one end region and said another inclined plane being on opposite sides of` a groove in a female thread section. said other end region and saidrstill another inclined plane being on op-y posite sides of a ridge of a male thread section.  
 4l. The invention as claimed in claim 40, in which` the forward ends of all of said inclined planes are located subs-tantially in a plane which is perpendicular to the axis of the coupling.  
 42. A coupling device comprising a duality of members,  
 each of said members including an end portion` having an outside thread, and an inside thread,  
 said inside and outside threads being fixed relal tive to each other, and having entrances positioned at different locations such that when said end portions of said members are brought into engagement and relatively rotated said `outside. thread of eachrof said members meshes with said inside thread of the other of said members so that said members assume a mated position,  
 said members being configured and arranged such that the outer edge surfaces of said members are in juxtaposition when` said members so assume said mated position and said members provide a substantially gap-`