Electrical plug connector with double casing

A plug connector suitable for connecting with a socket connector including a first internal screw thread is provided. The plug connector includes an internal casing having an inside space, a set of terminals disposed in said inside space, a sleeve tube and an external casing. The sleeve tube is fixed to said internal casing and includes an external hook. The external casing is movably covered to said internal casing and includes a first external screw thread, an internal hook and a concaved slot caving in the inner surface of the external casing facing to said internal casing. The internal hook forms one of walls of said concaved slot. The external hook is movably disposed in said concaved slot. When said socket connector screws to said plug connector, said external casing is pulled toward said socket connector, and said internal hook of said external casing contact said external hook of said sleeve tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date under 35 U.S.C. §119(a)-(d) of Taiwan Patent Applications No. 103203969 , filed Mar. 7, 2014.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a connector, and particularly to a plug connector.

Description of the Related Art

In general, a transmission cable and an electronic device are usually connected by a connector to transmit signals. The connector includes a plug connector, which is a male end, and a socket connector, which is a female end, for being connected with the plug connector. As to a prior plug connector, a casing of the plug connector is an integrally molded iron casing in which a the set of terminals is located, wherein conducting wires for signal transmission of the transmission cable are connected to the set of terminals in the iron casing by which the iron casing achieves electromagnetic shielding effect with respect to the set of terminals and the transmission cable. In addition, some plug connectors are injected with glue within the casing to achieve water-proof function.

Whereas, in the prior plug connector, it is very complicated to assemble the set of terminals and a transmission cable in an integrally-molded casing. Furthermore, after assembled, the assembled product needs to be transported to a glue-injection factory for the subsequent glue-injecting process, which consumes manpower and time cost.

SUMMARY OF THE INVENTION

The present invention provides a plug connector which is easily-assembled and provides excellent electromagnetic shielding and water-proof effect.

The present invention provides a plug connector suitable for connecting with a socket connector mainly comprising a first internal screw thread. The plug connector comprises an internal casing, a set of terminals, a sleeve tube and an external casing. The internal casing includes an inside space, a first end and a second end opposite to the first end. The set of terminals is located in the inside space. The sleeve tube is fixed on the second end and includes an external hook that extends toward the first end. The external casing, which is movably sleeved on the internal casing, comprises: a third end and a fourth end that opposite to the third end, a first external screw thread located in the third end, and an internal hook located in the fourth end, and a concaved slot located neighboring to the internal hook. The concaved slot is concaved on the inner surface of the external casing facing the outer surface of the internal casing, wherein the internal hook is on the walls of the concaved slot, and the external hook is movably received by the concaved slot. When the first internal screw thread of the socket connector is screwed into the first external screw thread of the plug connector, the external casing is pulled towards the socket connector such that the internal hook of the external casing contacts with the external hook of the sleeve tube.

According to an aspect of the present invention, the sleeve tube and the external casing are conductive.

According to an embodiment of the present invention, it further includes a transmission cable comprises: a plurality of first conducting wires covered by the isolating layer, and at least one second conducting wire which is exposed to the isolating layer wherein the first conducting wires pass through the sleeve tube and connects to the set of terminals, and the second conducting wire is contacted the sleeve tube.

According to an aspect of the present invention, it further includes a flexible ring that is disposed between the sleeve tube and transmission cable.

According to an aspect of the present invention, the second conducting wire which is extended from the sleeve tube and then is folded to insert into a gap between the flexible ring and the sleeve tube.

According to an aspect of the present invention, it further includes a retaining plug which is inserted into the second end of the internal casing, comprising a plurality of first holes and a plurality of second holes which are disposed along the extending direction of the set of the set of terminals and are connected with each other in which the plural set of terminals of the set of the set of terminals are disposed in the first holes of the retaining plug, the diameter of each first hole is larger than the diameter of each of the set of terminals, and the diameter of each set of terminals is larger than the diameter of each second hole.

According to an aspect of the present invention, the retaining plug is an insulator.

According to an aspect of the present invention, the internal casing includes a annular ring that is disposed in the first end, and the external diameter of the annular ring is larger than the internal diameter of the first screw thread of the external casing.

According to an aspect of the present invention, the internal casing includes a second external screw thread that is located in the second end, and the sleeve tube includes a second internal screw thread that corresponds to the second external screw thread; the sleeve tube is screwed into and fixed to the internal casing.

According to an aspect of the present invention, the internal casing includes an anti-rotation unit whose external diameter is larger than the internal diameter of the second internal screw thread.

Accordingly, in the present invention, the plug connector is assembled by, firstly, sleeving the sleeve tube on the transmission cable, sleeving the external casing on the internal casing, connecting the set of terminals to the transmission cable in the internal casing, and finally inserting the external hook of the sleeve tube into the internal hook of the external casing to complete the assembling of the plug connector. The present invention is appreciated that the above assembly is easier as compared to the prior plug connector which requires to assemble the set of terminals and the transmission cable within one integrally molded casing. Moreover, since the sleeve tube and the external casing are both conductive, the present invention provides better electro-magnetic shielding effect with respect to the set of terminals and the transmission cable. In addition, the present invention disposes a flexible ring between the sleeve tube and the transmission cable to achieve a water-proof function by which a manufacturer doesn't need to perform the glue injecting process within the casing to thus efficiently save cost and time. Since the second conducting wire is contacted with the sleeve tube, in a situation that the plug connector is being connected with the socket connector, thus, the sleeve tube is contacted with the external casing in such a manner that the second conducting wire is electrical conducted with the sleeve tube and the external casing to thus upgrade the electronic-magnetic shielding effect. Furthermore, the plug connector of the present invention, for purpose of acting as a stopper, is provided with the retaining plug located at the second end of the internal casing to avoid the detachment of the set of terminals.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

FIG. 1is a prospective view of a plug connector according to one embodiment of the present invention.FIG. 2is a cross-section view of the plug connector shown inFIG. 1.FIG. 3Ais a cross-section view of the plug connector100shown inFIG. 1from another viewing angle without the set of terminals and flexible ring.FIG. 3Bis a partial enlargement view ofFIG. 3A. Please refer toFIGS. 1 to 3B, which show that the plug connector100comprises an internal casing110, a the set of terminals120, a sleeve tube130, an external casing140, a transmission cable150, and a flexible ring160.

As shown inFIGS. 2 and 3A, the internal casing110comprises an inner space112, a first end114aand a second end114bthat are located on opposite sides, an annular ring116that is protruding from the first end114aand a second external screw thread118that is located in the second end114b. In this embodiment, the internal casing110is an insulator; the material of the internal casing is, for example, plastics, but not limited to this.

The set of terminals120is disposed in the inner space112, and in this embodiment, the set of terminals120appears from the first end114a, which means the socket connector10for connecting with the plug connector100(as shown inFIG. 4A) is able to be plugged into the first end114afrom the internal casing110to connect with the set of terminals120to transmit the signal.

The sleeve tube130comprises an external hook132that extends toward the direction of the first end114aand an second internal screw thread134that corresponds to the second external screw thread118, the external hook132and the second internal screw thread134are located in the end of the sleeve tube130near the internal casing110. In this embodiment, the sleeve tube130is fixed to the second end114bof the internal casing110by screwing the second internal screw thread134into the second external screw thread118of the internal casing110. Of course, in other embodiments, the sleeve tube130is also able to be fixed to the second end114bof the internal casing110by buckling or other methods.

In addition, to avoid the internal casing110over screwing into the sleeve tube130which also means that the internal casing110excessively screws towards the right ofFIG. 2or ofFIG. 3A, the internal casing110further includes an anti-rotation unit119that is located next to the second external screw thread118; the anti-rotation unit119has an external diameter D6larger than the internal diameter D7of the second internal screw thread134. Therefore, after the second external second screw thread118in the internal casing110that is the furthest from the second end114b(the second external screw thread118closest to the left ofFIG. 2orFIG. 3A) being screwed into the second internal screw thread134of the sleeve tube130, if the internal casing110keeps being screwed, the anti-rotation unit119would be stuck on the side wall of the second internal screw thread134of the sleeve tube130, and thus restrict the internal casing to move further towards the sleeve tube130.

The external casing140movably sleeves the internal casing110, and comprises a third end142aand a fourth end142bthat are located on opposite sides, a first external screw thread144located in the third end142a, an internal hook146located in the fourth end142band, a concaved slot148located next to the internal hook146. In this embodiment, when the socket connector10connects to the plug connector100, the third end142aof the external casing140contacts with the socket connector10, and the fourth end142bis the end which is far from the socket connector10. The concaved slot148is concaved on the surface of the external casing140that faces the surface of the internal casing110, and the internal hook146is one of walls of the concaved slot148. In this embodiment, the internal hook146is the right wall of the concaved slot148which is shown inFIG. 2orFIG. 3A. The external hook132of the sleeve tube130is contained in the concaved slot148, and in this embodiment, the width of the concaved slot148is larger than that of the external hook132of the sleeve tube130, and thus, the external casing140is relatively movable with respect to the sleeve tube130towards left and right of the figure.

As shown inFIG. 2, the transmission cable150comprises a plurality of first conducting wires154which are covered by an isolating layer152and at least one second conducting wire156that appears outside the isolating layer152. In this embodiment, the first conducting wires154are for signal transmitting; they pass through the sleeve tube130and then connect to the set of terminals120. In this embodiment, the second conducting wire156is a grounding wire, and the transmission cable150includes a plurality of second conducting wires156, but the number is not exclusive.

The flexible ring160is disposed between the sleeve tube130and the transmission cable150; more precisely, the flexible ring160is located in the sleeve tube130far from the internal casing110. In this embodiment, the flexible ring160is an O ring; its material could be flexible material such as rubber or silicone, rendering the flexible ring160to tightly seal the gap between the sleeve tube130and the transmission cable150, and thus the flexible ring achieves water-proof effect. Manufacturers can choose the flexible ring160sized by public scale present in the market according to the internal size of the sleeve tube130; thus to isolate fluid from the space enclosed by the internal casing110, the external casing140, the sleeve tube130and the flexible ring160. In this embodiment the flexible ring160is disposed in the plug connector to replace the conventional glue injecting process, which effectively saves producing cost and time.

In addition, as shown inFIG. 2, in this embodiment, the grounding second conducting wires156pass through the flexible ring160in the sleeve tube130and then is folded to reach into the gap157between the flexible ring160and sleeve tube130to contact with the sleeve tube130. In this embodiment, the sleeve tube130is made of metal, which makes the sleeve tube130conductive with the second conducting wire156. Of course, in other embodiments, it is not necessary to fold the second conducting wire156; after entering from the right end of the sleeve tube130shown inFIG. 2, the second conducting wire can directly be pinched by the flexible ring160and the sleeve tube130; the disposition of the second conducting wire156in the sleeve tube130is unlimited, as long as the second conducting wire156contacts with the sleeve tube130.

The socket connector10is connected with the plug connector100of this embodiment, making the device conductive from the set of terminals120; the relative position between the socket connector10and plug connector100is able to be maintained by screw connection after they are bolted. Through this screw connection of the two-pieces external casing140and sleeve tube130, the plug connector100in this embodiment is able to build electro-magnetic shielding effect with respect to the internal the set of terminals120and the transmission cable150. The detail is described below.

FIG. 4Ais cross-section scheme of the plug connector100bolted to the socket connector10, which is shown inFIG. 3A.FIG. 4Bis partial enlargement view ofFIG. 4A. Please refer toFIGS. 4A and 4B, in this embodiment, the socket connector10comprises a first internal screw thread12, and the external casing140comprises a first external screw thread144which corresponds to the first internal screw thread12. In this embodiment, once the plug connector100and socket connector10are connected, the relative positions between them is able to be fixed by screwing the first internal screw thread12of the socket connector10into the first external screw thread144of the external casing140of the plug connector100. More specifically, because the external casing140movably sleeves the internal casing110, in the process of screwing the first internal screw thread12into the first external screw thread144of the plug connector100, the external casing140is pulled toward the socket connector10(in the left of the figure) in relation to the sleeve tube130and the internal casing110, making the concaved slot148of the external casing140move toward left, which makes the internal hook146of the external casing140contact with the external hook132of the sleeve tube130. In this embodiment, the external casing140is made of metal, under this condition, the external casing140is electrically connected with the sleeve tube130.

In this embodiment, because the grounding second conducting wire156(as shown inFIG. 2) contacts with the sleeve tube130, and the external hook132of the sleeve tube130contacts with the internal hook146of the external casing140, and the first external screw thread144of the external casing140contacts with the first internal screw thread12of the socket connector10, the would-be grounding current goes through the second conducting wire156, and then goes through the sleeve tube130and the external casing140to the socket connector10. In this embodiment, the electro-magnetic shielding effect is effectively enhanced by grounding the sleeve tube130and the external casing140.

In addition, to prevent the external casing140that sleeves the internal casing110from detaching easily, in this embodiment, by the disposition that the third end142ain the third end of the external casing140is on the right-hand side of the annular ring116protruding from the first end114aof the internal casing110, and the external diameter D3of the annular ring116is larger than the internal diameter D4of the third end142aof the external casing140, the annular ring116can thus restricts the moving distance of the external casing140that is away from the sleeve tube130(in the left of the figure) to prevent the external casing140detaching from the internal casing110.

Traditional plug connectors only comprise single iron case with tiny space which causes difficulties while assembling the set of terminals and transmission cable. In addition, the glue injecting process must be executed to achieve water-proof function, which increases the complexity of producing procedure. Compared with prior plug connectors, the plug connector100in this embodiment comprises two metal cases including the external casing140and the sleeve tube130, and the assembly steps are: at first, plugging the flexible ring160into the sleeve tube130, and make the sleeve tube130sleeve the transmission cable150; make the external casing140sleeve on the internal casing110; connecting the set of terminals120inside the internal casing110with the transmission cable150; then screw the second external screw thread118of the internal casing110into the second internal screw thread134of the sleeve tube130; finally, insert the external hook132of the sleeve tube130into the concaved slot148of the external casing140, then the assembly is completed. The assembling procedure applied by the present invention is not only much simpler than that of the prior plug connectors, but also achieve excellent water-proof effect. The plug connector100in this embodiment has passed IP67dust and water proof test (remain operational in water at 1 meter deep for 40 minutes) in experiment.

FIG. 5is a partial schematic diagram of the plug connector of another embodiment of the present invention.FIG. 6is a schematic diagram ofFIG. 5from another viewing angle.FIG. 7is a cross-section view of the plug connector shown inFIG. 5that has been attached with the sleeve tube. Please refer toFIGS. 5 to 7; the main difference between the plug connector200in this embodiment and the plug connector100of the last embodiment is that the plug connector200in this embodiment further comprises an electrically isolated retaining plug270, which is inserted into the second end214bof the internal casing210.

As shown inFIG. 7, the retaining plug270comprises a plurality of first holes272and second holes274which are disposed along the extending direction of the set of terminals and are connected with each other; a plurality of the set of terminals222of the set of terminals220are contained in the first holes272of the retaining plug270, and the diameter D1of each first holes272is larger than the diameter D5of the terminal222, and the diameter D1of each the first holes is larger than the diameter D2each second holes274. The first conducting wires of the transmission cable (not revealed in the Figures) is able to connect with the set of terminals222through the second holes274. The plug connector200of this embodiment is able to prevent the detachment of the set of terminals222by contracting the passages between the first holes272and the second holes274on the retaining plug270, which effectively restrain the position of the set of terminals222.

To summarize the above, the plug connector revealed by the present invention could be assembled by, firstly, sleeving the sleeve tube on the transmission cable, sleeving the external casing on the internal casing, connecting the set of terminals to the transmission cable in the internal casing, and finally inserting the external hook of the sleeve tube into the internal hook of the external casing to complete the assembling of the plug connector. The present invention is appreciated that the above assembly is easier as compared to the prior plug connector which requires to assemble the set of terminals and the transmission cable within one integrally-molded casing. Moreover, since the sleeve tube and the external casing are both conductive, the present invention provides better electro-magnetic shielding effect with respect to the set of terminals and the transmission cable. In addition, the present invention disposes a flexible ring between the sleeve tube and the transmission cable to achieve a water-proof function by which a manufacturer doesn't need to perform the glue injecting process within the casing to thus efficiently save cost and time. Since the second conducting wire is contacted with the sleeve tube, in a situation that the plug connector is being connected with the socket connector, thus, the sleeve tube is contacted with the external casing in such a manner that the second conducting wire is electrical conducted with the sleeve tube and the external casing to thus upgrade the electronic-magnetic shielding effect. Furthermore, the plug connector of the present invention, for purpose of acting as a stopper, is provided with the retaining plug located at the second end of the internal casing to avoid the detachment of the set of terminals.