A DEVICE FOR CONNECTING A PLUG TO A SOCKET IN COAXIAL CONNECTORS

Abstract: A device for connecting a plug (14) to a socket (12), in a coaxial connector, in which the coupling thereof is obtained by engagement of a coupling member (48, 50, 148) within a corresponding slot (18) of socket (12). Said coupling member (48, 50, 148) comprises a locking element (48, 148) radially movable within plug (14), the motions of which are controlled by the resilient projections (150) of an annular ring (160), or by engagement of a cylindrical projection (50) thereof with differential thickness portions (40, 42) of a sleeve (30), axially displaceable on plug (14), spring means (38) being then provided in order to keep sleeve (30) in a position corresponding to the engagement of said locking element (48) within groove (18).

Description: "A DEVICE FOR CONNECTING A PLUG TO A SOCKET IN COA¬ XIAL CONNECTORS" This invention relates to a device for connec- ting a plug to a socket in coaxial connectors. The coaxial connector the present invention refers to is particularly usable in telecommunica¬ tion apparatus for radiofrequency signal transmis¬ sion. Coaxial connectors of the type mentioned above are known and it is also known that the coupling between a connector plug and socket is presently performed by using two types of junctions, as spe¬ cified hereinafter. A first type of coupling is known as a threaded ring nut plug-to-socket cou¬ pling so defined in that the plug is provided with a threaded ring nut freely rotatable thereon, which can be screwed onto the threaded end of the socket. This type of coupling ensures a stable and secure junction between said members, therefore it provi¬ des a pulling apart resistance at such a level as to prevent undesired disconnections of the plug from the socket, in that said disconnection can be obtained only by completely unscrewing the threaded ring nut from the socket. The above approach proves advatangeous only when the plurality of plug-and-socket assemblies are located quite apart from each other on support boards. In fact, the threaded ring nut coupling has the disadvantage of being difficult to handle when the connectors are quite close together, due to the limited room available, whereby it is difficult, and sometimes impossible to operate the ring nut manually in order to screw it on. in order to overcome the above limitation and drawback, there has been provided a second type of coupling defined as snap-on coupling. In this type of coupling there is provided a resilient stop spring built into the plug, which gets deformed while the plug is inserted into the socket and, when said insertion operation is over, goesback to a normal position, which is now a wor¬ king position, by engagement of the end thereof in¬ to a suitable recess provided within the socket bo- dy. The snap-on coupling or connection mentioned above is used in order to obtain a fast making or breaking of the connection, and it is in general preferred to the threaded ring nut coupling in case of space availability problems i.e. when the con- nectors are a large number and they are located ve¬ ry close to each other. However, this type of connection has the draw¬ back that the pulling apart resistance of the cou- pling mechanism is determined by the force of enga¬ gement of the resilient spring within the socket, whereby the value thereof is certainly lower than that of the threaded ring nut coupling. Therefore, it may happen that the uncoupling of one or more coaxial connectors causes the breaking of other connectors which instead have to stay coupled to each other. Therefore the operator, besides the in¬ herent difficulties in breaking only the connectors whose uncoupling is required, finds it difficult to correctly reconnect those connectors which have been unnecessarily uncoupled. There has now been contrived, and it makes the subject of this invention, a device for connecting the plug to the socket of coaxial connectors, which overcomes all the drawbacks of conventional cou¬ pling devices. A first advantage of the inventive device is the fact that it is able to provide a pulling apart resistance comparable to that of a threaded ring nut coupling, while making the handling thereof ea- A further associated advantage obtainable through the device of this invention is the fact that it may be advantageously used, without any particular problem, in those cases where the room available is extremely limited. The features as well as further advantages of the device according to this invention will become apparent from the following detailed description of a non limiting embodiment thereof, made referring to the attached drawing, wherein: Figure 1 is a side view, partially cut away, showing the plug and the socket before they are coupled; Figure 2 is a view similar to Figure 1, which shows the beginning of the coupling of the plug to the socket; Fugure 3 is a view similar to Figure 1, which shows an intermediate step in the coupling opera- tion of the socket with the plug; Figure 4 is a view similar to Figure 1, sho¬ wing the plug and the socket coupled to each other; Figure 5 is a side view, partially cut away, of a further embodiment of the invention, showing a modified plug and the socket before they are coupled; Figure 6 is a view similar to Figure 5, that shows an intermediate step in the coupling opera¬ tion of the plug to the socket; Figure 7 is a view similar to Figure 5, sho¬ wing the plug and socket coupled to each other; Figure 8 is a side view, partially cut away, of a ring nut forming part of the modified plug of Figure 5; Figure 8A is a front view of the ring nut of Figure 8; Figure 9 is a longitudinal cross section of a locking ring to be inserted into the ring nut of Figures 8 and 8A; Figure 9A is a front view of the locking ring of Figure 9; and Figure 10 is a side view, partially cut away, of an annular-ring to be secured to the outer pe¬ riphery of the ring nut of Figures 8 and 8A. Referring first to Figure 1, the junction of the pair of coaxial connectors made by means of the device of this invention is shown in general at 10 and it comprises substantially a socket shown in general at 12 and a plug shown in general at 14. Socket 12 is known per se, therefore only that much thereof which is necessary to the understan¬ ding of the inventive device is shown and described herein. Said socket comprises a substantially cylin- drical body 16 provided, at the end thereof, with an annular peripheral groove 18 having a substan¬ tially semicircular shape in cross-section. Within socket 12 there is located the terminal member for the effective electrical connection, which is neither shown nor described in detail, since it is known per se. Still referring in parti¬ cular to Figure 1, plug 14 will be described, which is provided with the device of this invention. Plug 14 is substantially comprised of an es- sentially tubular ring nut 20 which is fastened in a known fashion, at an end thereof, to the end of connector body 22. Within ring nut 20, whose mouth 24 is frusto- conically flared, there is located an effective e- lectrical connection member, only partially repre¬ sented in that it is known per se, and shown at 26, which is adapted to connect with the inside of body 16 of socket 12. Ring nut 20 has a constant thickness for al- most the whole length thereof and is provided, at the free end thereof, with a peripheral annular projection 28 of a suitable width, adapted to pro¬ vide a stop part for a member slidingly engaged thereon as it will be described in the following. Ring nut 20 bears a sleeve 30 mounted in a substantially coaxial position thereon, and which comprises the actuating member of the inventive coupling, and for that reason is provided, in a substantially intermediate area thereof, with a pe- ripheral slot 32, adapted to enable the user to control the axial displacements of sleeve 30. Slee¬ ve 30, behind slot 32, is provided with an outwar¬ dly bent edge which extends into an essentially tu¬ bular wall 34, which is substantially parallel to the opposite face of ring nut 20. Wall 34 and the face of ring nut 20 opposite thereto define a cavi¬ ty 36 wherein there is located a coil spring 38, surrounding the corresponding portion of ring nut 20. Tubular wall 34 has a diameter which is sli¬ ghtly larger than the diameter of body 22, whereby sleeve 30 may be moved back as it is more clearly shown in Figure 3, against the action of spring 38. According to a further particularly advanta- geous feature of the device of this invention, sleeve 30 is provided, in the portion thereof lying between slot 32 and the free end thereof, with a variable diameter cross section, as it will be pointed out in the following. in particular sleeve 30 has, in said portionm a variable thickness, for actuating a coupling mem¬ ber or pin. Sleeve 30, as it is shown in the atta¬ ched Figures, has a first portion 40 of such a thickness that the inner surface thereof substan- tially contacts the outer surface of ring nut 20. First portion 40 extends and merges therewith at a thinner second portion 42, and the latter portion 42 extends into a still thinner further portion 44, a shoulder 46 being provided between portions 42 and 44, said shoulder being adapted to abut against the inner end of projection 28 of ring nut 20. In this way, when sleeve 30 is not actuated by the u- ser, spring 38 pushes it against projection 28 which therefore provides a stop member for sleeve 30. The member or pin of the coupling of the in¬ ventive device comprises, in the exemplary embodi¬ ment considered herein, a substantially semi- spherical body 48, which is inserted in a suitable bore provided in the wall of ring nut 20, being a- ble to move in a substantially radial direction. Substantially semispherical body 48 is provi¬ ded, rearwardly thereof, and integrally therewith, with a substantially cylindrical projection 50 a- dapted to be received, in rest conditions (Figure 1), or coupling conditions (Figure 4), in a larger diameter portion of the bore wherein substantially semispherical body 48 is inserted. This shape has been studied in that the displacements the coupling member or pin 48, 50 is able to perform must com¬ prise only a backward motion from the Figure 1 po¬ sition to the Figure 3 position, and the return mo¬ tion to the position shown in Figure 1. From what has been described above, there should be apparent the advantages deriving from the use of the coupling device of this invention, the most remarkable among which will become understan¬ dable from the following detailed description of how said device can make or break the coupling of plug connector 14 relative to socket 12. It is assumed that operations start from the Figure 1 condition, wherein socket 12 is uncoupled from plug 14. Sleeve 30, under the action of spring 38, is kept in the position shown in the above Fi- gure, wherein shoulder 46 of sleeve 30 abuts against projection 28 of ring nut 20. The pin mem¬ ber of coupling 48, 50, partially projects within ring nut 20. Then plug 12 is partially inserted into socket 14, as shown in Figure 2, until the end of cylin¬ drical member 16 abuts against semispherical por¬ tion 48 of pin 48, 50. At this point, through a ma¬ nual actuation or by means of a suitable tool ha- ving a fork-shaped end, inserted into slot 32, sleeve 30 is made to move backwards to the position shown in Figure 3, wherein it is retained by com¬ pression spring 38. In this condition, owing to the first reduced thickness portion 42 of sleeve 30, and to the simultaneous further introduction of cy- lindrical body 16 of socket 12, the pin of coupling 48, 50 is made to move radially back in order to enable a further forward motion of cylindrical body 16 of socket 12 until groove 18 thereof moves to a position corresponding to the pin of snap-on cou- pling 48, 50. At this point sleeve 30 is released, whereby spring 38 makes it to move axially forward in such a way that sleeve 30 gets engaged again, at higher thickness portion 40 thereof, with pin 48, 50, dri- ving semispherical member 48 into position within groove 18 of socket 12 cylindrical body 16. In such a way the locking position is obtained. From the above it should be readily understood how easily the coupling may be obtained, and it is also apparent that the pulling apart resistance of said coupling is remarkable, in that pin 48, 50, once it is locked, is securely maintained in the locking condition by sleeve 30. The uncoupling operation is accomplished by performing in a substantially reverse sequence the operations described above, therefore it should be apparent that this type of actuation is extremely easy and fast. Referring now to Figures 5 to 10 showing an alternative embodiment of the present invention, wherein corresponding parts have the same reference members as in Figures 1 to 4, the plug 14 is sub¬ stantially comprised of an essentially tubular ring nut 120 which is fastened at one of its ends, in a manner known per se to the end of a connector body 22. Within ring nut 120 there is located an effec¬ tive electrical connection member, only partially represented in that it is known per se, and shown at 26, which is adapted to connect with the inside of body 16 of socket 12. Ring nut 120 has a constant thickness for al¬ most the whole length thereof and is provided, at the threaded end thereof , with a peripheral annular projection 154 of a suitable width, adapted to pro¬ vide a stop part for a member slidingly engaged thereon as it will be described in the following. Ring nut 120 bears a sleeve 130 mounted in a substantially coaxial position thereon, and which comprises the actuating member of the coupling, ac¬ cording to the invention, and for that reason is provided, in a substantially intermediate area the¬ reof , with a peripheral slot 32 , adapted to enable the user to control the axial displacements of sleeve 130 . Sleeve 130 , behind outside slot 32 , is provided with an inner circular slot 156 which is substantially parallel to the opposite face of ring nut 120 . Slot 156 and the face of ring nut 120 op¬ pos ite thereto define a circular gap 136 wherein there is located ' a peripheral rib 158 protruding from the outer surface of ring nut 120 . According to a further particularly advanta¬ geous feature of the device of this inventionm sleeve 130 is provided, at the free end 124 or mouth thereof with an inner rim having an essen- tially trapezoidal cross section for actuating a coupling member or locking element 148. In particu¬ lar the mouth 124 of sleeve 130 is frusto-conically flared. A locking element is shaped as an annular ring 160 having at least two longitudinally extended projections 150, the ends of which are enlarged to form each two opposite protruding portions 148. Annular ring 160 is frontally coupled with ring nut 120 so as to allow its projections 150, 148 to enter corresponding slots 162, and therea¬ fter a locking ring 152 is engaged on a further pe¬ ripheral rib 164 of ring nut 120 in order to pre¬ vent the annular ring 160 from getting free of ring nut 120. The thus obtained assembly is surrounded by a sleeve 130 as discussed above. When the whole assembly is at rest, the loc¬ king ring 152 does generally not interfere with the protruding portions 148 of annular ring 160. In the circumstances plug 14 may easily be inserted in a socket 12 (Figure 6) because of an opening out ac¬ tion by the front end of socket 12 on the inner parts of protruding portions 148 of plug 14. As a matter of fact, when plug 14 is inserted into soc- ket 12 the outer contour of the cylindrical body of socket 12 moves axially the projections 150 of an¬ nular ring 160 thus releasing the protruding por¬ tions 148 from the constraint of locking ring 152 that would otherwise prevent the resilient projec¬ tions 150 from radially widening, and allows the complete connection of socket 12 and plug 14 by snapping the protruding portions 148 into groove 18. The locking ring 152 has an inner flaring at its end corresponding to the protruding portions 148 of annular ring 160, which flaring acts as an inclined plane 166 with respect to the outer cor¬ ners of protruding portions 148. As a consequence any tractive force applied to socket 12 or connec¬ tor body 22 in order to disconnect them moves sli¬ ghtly the locking ring 152 together with ring nut 120 and connector body 22 to the right of Figures 5 to 7, thus pressing upon the inclined plane 166 the protruding portions 148 that remain forced within the groove 18 of the socket 12, and stopping the disconnection (Figure 7) . The disengagement of socket and plug is on the contrary easily feasible by applying the above tractive force to the slidably movable sleeve 130 that can axially shift with regard to the connector body 22 and ring nut 120 integral therewith between two stop positions formed by its own inner rim 170 at mouth 124 and the side face 168 of annular projection 154 of ring nut 120. The axial movement of sleeve 130 to disconnect plug 14 causes the inner rim 170 to abut against annular ring 160 and to push radially it so as to * open out its projections 150 and disengage protru- ding portions 148 from groove 18 of socket 12 (Fi¬ gure 6) . Plug 14 can thus be disconnected from soc¬ ket 12. A particular advantage of this embodiment is to allow the use of this connection even when the plug is secured at its back to a board and the soc¬ ket is free; as a matter of fact both said members can also be disconnected by applying to the sleeve 130 a pushing force (from left, Figures 5 to 7) in¬ stead of a tractive force (from right) . It should eventually be understood that varia¬ tions and/or modifications may be made to the devi¬ ce for connecting a plug to a socket in the coaxial connectors according to this invention, without thereby exceeding the scope of protection thereof.

Claims: CLAIMS 1. A device for connecting a plug to a socket in coaxial connectors, wherein the socket comprises a substantially tubular body provided with an outer peripheral groove wherein a plug coupling member gets engaged when the socket gets inserted into the plug, characterized in that on the outside of the plug (14) there is mounted an axially movable slee¬ ve (30, 130), said coupling member comprising a locking element (48, 148) radially movable within a cavity through the plug (14), between a protruding position where it partially projects inside the plug (14) in order to get engaged within a proove (18) of the socket (12), and a retracted position where it has completely re-entered into said cavity for uncoupling the socket (12) from the plug (14), clamping means being provided to avoid an undesired disconnection of both said socket (12) and plug (14). 2. The device of claim 1, characterized in that said clamping means comprises a contoured pin (48, 50) to be engaged with portions (40, 42) ha¬ ving different thickness of said sleeve (30), the locking of sleeve (30) in a position where it keeps the pin (48, 50) protruded into said groove (18) being provided by the engagement of a pair of oppo¬ site projections (46, 28) of the sleeve (30) and a ring nut (20), said locking condition being main¬ tained by spring means (38). 3. The device of claim 2, characterized in that said contoured pin (48, 50) comprises a sub¬ stantially semispherical body (48) adapted to par¬ tially project inside plug (14), said body being provided, in the rear portion thereof, with an in- tegral projection (50) having a cross-section lar¬ ger than that of body (48) , adapted to engage in a larger cross-section portion of the bore through which said pin (48, 50) can slide. 4. The device of claim 2, characterized in that said differential thickness portions (40, 42) of sleeve (30) have such a thickness that the first of said portions is substantially contacting the outer surface of plug (14), while the second of said portions has a lower thickness, and joins first portion (40) through a fillet. 5. The device of claim 4, characterized in that said lower thickness portion (42) ends with a shoulder (46), adapted to abut against an outer projection (28) of plug (14). 6. The device of claim 1, characterized in that sleeve(30) is provided, in the rear portion thereof, with a substantially tubular wall (34), having a slightly larger diameter than connector body (22), between said tubular wall (34) and plug (14) there being located a spring (38) having an end thereof engaged against an edge of sleeve (30) substantially perpendicular to said wall (34), and the other end abutting against body (22). 7. The device of claim 1, characterized in that said clamping means comprises a locking ring (152) provided with an inclined plane (166) that keeps forced within said groove (18) the protruding portions (148) of an annular ring (160) when an un¬ due tractive fore is applied to both said socket (12) and plug (14) . 8. The device of claim 7, characterized in that said locking ring (152) is axially integral with a ring nut (120) which is in turn integral with a connector body (22) of said plug (14), and that said protruding portions (148) are integral with said annular ring (160) through resilient projections (150). 9. The device of claim 7 or 8, characterized in that an outer surrounding sleeve (130) is provi- ded around said plug (14) to disengage said protruding portions (148) of the annular ring (160) from said inclined plane (166) of the locking ring (152) so as to enable the disconnection of said socket (12) and plug (14). 10. The device of claim 1, characterized in that sleeve (30, 130) has on the periphery thereof, holding means for the operator. 11. The device of claim 10, characterized in that said means comprise a peripheral slot (32) of sleeve (30, 130). 12. A device for connecting a plug to a socket of coaxial connectors, substantially as described above and shown in the attached figures.

Inventors: CRIPPA SIRO, CRIPPA, SIRO
Applicants: CM SRL, CM S.R.L.
Application year: 1991
Main classification: H01R13
IPC codes: H01R13