MXPA99008849A - Switching coaxial jack - Google Patents

Abstract

A switching coaxial jack includes first and second parallel aligned electrically conductive coaxial center conductors. The center conductors are divided into front and rear portions. The rear portions include movable springs to separate the rear portions from the front portions. A V-shaped switching spring connects the rear portions. Levers push the rear portions out of connection with the switching spring and into connection with the front portions upon insertion of plugs into forward ports of the jack.

Description

COAXIAL SWITCHING PLUG BACKGROUND OF THE INVENTION Field of the invention This invention relates to coaxial plugs. More particularly, this invention is concerned with a coaxial switching plug which is suitable for use in high speed frequency transmission applications.

Description of the prior art The coaxial switching sockets are well known. An example of such is shown in U.S. Patent Nos. 4,749,968 and 5,457,062 both issued to Burroughs. Another example is shown in U.S. Patent No. 5,246,378 issued to Seiceanu. The coaxial switching sockets of the prior art included two generally solid central conductors disposed in parallel alignment in an electrically conductive grounded box. A switching assembly is positioned between the two central conductors. The switching assembly includes a V-shaped spring with a first end driven against a first of the central conductors and with a second end urged against a second of the central conductors.

REF: 31088 As a result, the center conductors are in normal signal flow communication such that an electrical signal on one of the core conductors passes through the switching assembly to the other center conductor. Such coaxial switching plugs would be commonly used in the telecommunications or video transmission industries. A rear end of the box is provided with connectors for a semi-permanent or permanent connection to coaxial cables. The front end of the center conductors is provided with plug holes to receive a plug or plug of predetermined dimensions. Normally, such switching plugs are operated without plugs or plugs inserted in the holes. Thus, a signal entering a central conductor from one of the subsequent connectors passes through the switching assembly and is transmitted out of the plugging device by means of the other rear coaxial connector. From time to time, it is desirable to have access to the plug in order to derive the signal or introduce a new signal. To do this, insert a plug with coaxial cable attached to one of the front holes. After inserting the plug plug into the front hole, the plug plug engages with a V-shaped spring to cause it to be moved from the center conductor associated with the hole to which the plug is inserted. By causing the V-shaped spring to be moved away from the center conductor, the center conductor is no longer connected to the other center conductor such that the signal passes directly along the entire length of the center conductor and outward of the hole. In addition to breaking or interrupting the connection between the two central conductors of the plug, the insertion of the plug also causes the other central conductor to be electrically grounded through a resistor in such a way that the desired electrical impedance of the system is maintained. With the structure thus described, the normal signal flow from the connector after the rear connector passes through the V-shaped spring. There is a substantial length of the core conductors extending beyond the V-shaped spring without connection to any ground or other connection source. In the past, these free lengths of core conductors usually had little or no problem in the telecommunications industry. However, with progressively higher transmission frequencies, the free lengths of the center conductors may exhibit distortions to the signals or otherwise impair the integrity of the signal. Another problem associated with the coaxial switching sockets of the prior art is the admission of dust or other contaminants to the switching assembly. Such plugs commonly have free air flow through the front holes to the plug's switching assembly.

BRIEF DESCRIPTION OF THE INVENTION In accordance with a preferred embodiment of the present invention, a coaxial switching plug device is described having an electrically conductive coaxial central conductor extending from a rear portion to a front portion. A second coaxial center conductor is also included in the device. The rear portion of the first central conductor includes an electrically conductive movable portion that is movable between a first position and a second position. The movable portion is disposed in electrical contact with the second central conductor and electrically disconnected from the front or front portion of the first central conductor when the movable portion is in the first position. The movable portion is disposed in electrical contact with the front portion and electrically disconnected from the second center conductor when the movable portion is in the second position. An actuator moves the movable portion from the first position to the second position when a coaxial cable is attached to the front or front portion of the first center conductor.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view (with a cover removed) of a coaxial switching plug device according to the present invention shown with a plug partially inserted into a front hole of the plug device but with the plug still not coupled with a switch actuator; Figure 2 is the view of Figure 1 with the plug inserted additionally to a first hole of the device; Figure 3 is the view of Figures 1 and 2 with the shown plug still inserted further into the device; Figure 4 is the view of Figures 1-3 with the plug shown fully inserted into the device; Figure 5 is a side sectional view of the plug device of Figure 1 without any pins inserted into the device; Figure 6 is a view taken along line 6-6 of Figure 1 (but with the peg removed for purposes of clarity); Figure 7 is a view taken along line 7-7 of Figure 1; Figure 8 is a view taken along line 8-8 of Figure 1; Figure 9 is a front perspective view of a new dielectric insert for retaining a central conductor; Figure 10 is a rear perspective view of the insert of Figure 9; Figure 11 is a front plan view of the insert of Figure 9; Figure 12 is a side elevational view of the insert of Figure 9; Figure 13 is a view taken along line 13-13 of Figure 11; Figure 14 is a view taken along line 14-14 of Figure 11; Figure 15 is a view taken along line 15-15 of Figure 12; Figure 16 is a front perspective view of an alternative embodiment of a new dielectric insert; Figure 17 is a rear perspective view of the insert of Figure 16; Figure 18 is a front or front plan view of the insert of Figure 16; Figure 19 is a view taken along line 19-19 of Figure 18; Figure 20 is a front perspective view of still a further embodiment of a new dielectric insert; Figure 21 is a front elevational view of the insert of Figure 20; Figure 22 is a side elevational view of the insert of Figure 20; Figure 23 is a view taken along line 23-23 of Figure 21; Figure 24 is a view taken along line 24-24 of Figure 21; and Figure 25 is a view taken along line 25-25 of Figure 22.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to the various figures of the drawings in which identical elements are numbered identically from beginning to end, a description of the preferred embodiment of the present invention is now provided. The present invention consists of a device coaxial switching plug. The plug device 10 includes an electrically conductive box 12 and electrically connected to molded ground. The box 12 includes a front wall 14, a rear wall 16 and upper and lower walls 18, 20. The plug device further includes a side wall 22 and a side cover 24 (shown only partially in Figure 1 in such a way that the internal elements can be visualized). The box 12 includes an inner wall 26 which extends parallel to the end or end walls 14, 16 and completely between the side walls 22, 24 and the upper and lower walls 18, 20. The inner wall 26 cooperates with a segment of 26a wall of cover 24 (Fig. 8) for dividing an interior of the box into a front orifice chamber 28 and a rear switch chamber 30. As shown in the figures, the front wall 14 of the case 12 includes a first plug hole 32 for receiving a pin 33 of predetermined dimensions. The front wall 14 further includes a second plug hole 34 for receiving such a plug. The holes 32, 34 are in parallel alignment and each aligned with first and second receiver coaxial connectors 36, 38 disposed on the rear wall 16. The connectors 36, 38 can be any well-known connector (such as so-called BNC connectors) or holes for semi-permanent or permanent connection to coaxial cables. Holes 32, 34 include grounding fasteners 40 for engaging the grounding sleeve of an inserted plug 33 and for electrically connecting the grounding sleeve to the box 12. Axially aligned within each of the holes 32, 34 there are first and second conductors 42, 44 front centrals respectively for defining a central needle or terminal of a plug plug 33 received in the holes 32, 34 respectively. The central conductors 42, 44 are held in axial alignment in the holes 32, 34 by dielectric insertion pieces 46, 48. The dielectric insertion pieces 46, 48 are received under pressure within the receptacles or cavities formed in the interior wall 26. .

While it is shown that the inserts 46, 48 are solid dielectric cylinders in Figs. 1-8 for ease of illustration, alternative designs may be used. A preferred design will be described later with reference to Figures 9-25. The first and second rear center conductors 50, 52 are held aligned coaxially within the rear connectors 36, 38 and held in axial alignment for supporting the dielectric insertion parts 54, 56 contained within the rear wall 16. The first front and rear center conductors 42, 50 cooperate to define a first complete central conductor. The second front and rear center conductors 44, 52 cooperate to define a second full center conductor. It will be noted that the dielectric inserts 46, 48 resist the flow of powder through the holes 32, 34 and through the wall 26 into the chamber 30. Similarly, the inserts 54, 56 resist the flow of powder to through the connectors 36, 38 to the chamber 30. The first front center conductor 42 includes a spring portion 42a extending from the insert 46 to the chamber 30. The first rear center conductor 50 includes a "spring" portion. 50a which similarly extends from the dielectric insert 54 to the chamber 30. Similarly, each of the central conductors 44, 52 includes spring portions 44a, 52a extending from the dielectric insert 48, 56 to the chamber 30. A switching assembly 60 is contained within the chamber 30. The switching assembly 60 includes a terminating fastener 62 having first and second termination contacts 64.66 arranged adjacent the free ends of the springs 42a, 44a. The termination holder 62 is connected to a box 12 electrically connected to ground through a resistor 68. The fastener 62 is carried on a dielectric base 63 inserted inside the chamber 30. The base 63 includes dielectric projections 65 that support the springs 42a, 50a, 44a and 52a. A V-shaped switching spring 70 is mounted within the chamber 30 on a dielectric support post 72 that is integrally formed with and extends from the base 63. The spring includes a first spring arm 70a and a second spring arm. dock 70b. The arm 70a of the spring is urged toward the electrical contact with the termination contact 64. The arm 70b of the spring is urged toward the electrical contact with the second termination contact 66.

The contacts 42a, 44a of the spring of the central conductors 42, 44 are driven towards the termination contacts 64, 66 respectively. To prevent direct connection of the springs 42a, 44a with the termination contacts 64, 66, dielectric spacers 80, 82 are positioned between the springs 42a, 44a and termination contacts 64, 66. Thus, in the absence of deflection forces, the Springs 42a, 44a are spliced against dielectric spacers 80, 82 (Figure 1). The separators 80, 82 are formed with and project from the base 63. The springs 50a, 52a of the rear center conductors 50, 52 are urged towards the ends 70a, 70b of the V-shaped commutator spring 70. In the absence of any force acting to displace the springs 50a, 52a (Figure 1), the springs 50a, 52a have their free ends spliced to the free ends of the springs 70a, 70b. The springs 50a, 52a urge the springs 70a, 70b of the termination contacts 64, 66. The dielectric support posts 84, 86 (projecting from the base 63) prevent overflexing of the springs 70a, 70b and keep the spring pairs 50a, 70a and 52a, 70b in electrical contact. In the drawings, the springs 50a, 52a are shown urged against the springs 70a, 70b. In addition to the natural predisposition of the springs 50a, 52a (or as an alternative to such a predisposition) complementary springs (not shown) (eg, extending between the side walls 18, 20 and the levers 90, 92) could be provided. to drive the levers 90, 92 to the position shown in Figure 1. First and second dielectric levers 90, 92 are provided to act as actuators for moving the springs 50a, 52a from the first position shown in Figure 1 to a second position (shown with respect to spring 50a in Figure 4). The levers 90, 92 include cam ends 90a, 92a, positioned adjacent the holes 32, 34. The levers 90, 92 terminate at second ends 90b, 92b within the chamber 30. A cut 63a is formed in the base 63 for provide space for the movement of the lever 90. The ends 90b, 92b are provided with narrowly spaced posts 90b ', 92b'. The free ends of the springs 50a, 52a are received at the posts 90b ', 92b' for reasons that will become apparent. Each of the levers 90, 92 rotates about a common pivot pin 100. The pivot pin 100 is positioned within a central opening in the wall 26. The levers 90, 92 are sized to substantially fill the opening such that the powder can not easily pass through the opening from the chamber 28 to the chamber 30. The cam surfaces 90a, 92a are positioned in such a way that the levers are rotated about the bolt 100 after the insertion of a pin 30 to the holes 32, 34 respectively. With the structure thus described, the operation of the new plug of the invention creation will now be described with initial reference to Figure 1. In Figure 1, the plug device 10 is shown with a plug partially inserted into the hole 32 but still does not engage with the cam 90a. Thus, a signal flowing along the central conductor 50 passes through the arm 51a of the spring and the V-shaped spring 70. Then the signal is transmitted from the arm 52a of the spring and the central conductor 52. No portion of the The signal passes through the springs 42a, 44a or the central conductors 42, 44 since the free ends of 42a, 44a are spaced apart from the movable springs 50a, 52a. In Figure 1, the springs 50a, 52a are shown in a first position where they are in contact with the V-shaped spring (and hence in electrical contact with each other) and electrically and physically disconnected from the springs 42a, 44a. Figures 2-4 show the operation of the plug device 10 after insertion of the plug pin 33 into the hole 32. While the operation with the insertion of a plug plug into the hole 34 is not shown separately; it will be appreciated that it is identical to the insertion operation of the pin 33 into the hole 32. As a pin 33 is inserted into the hole 32, the forward end of the plug sleeve engages with the cam surface 90a to cause it to be displaced. The displacement of the cam surface 90a causes the alternative displacement of the end 90b. As the end 90b moves upward in the view of Figure 2, the post 90b urges the spring 50a away from its predisposed or driven position. As shown in Figure 2, the spring 50a is electrically contacted with the spring 42a before the V-shaped spring end 70a comes into contact with the termination contact 64. As shown in FIG. Accordingly, in this position, there is no grounding contact and the springs 50a, 42a and 52a are electrically connected. As the spring 50a moves further upwards in response to the further insertion of the pin 33 (Fig. 3), the end 70a of the spring of the V-shaped spring 70 moves in contact with the first termination contact 64. It will be noted that when the spring 70a is in electrical contact with the first termination contact 64, the end 70a of the V-shaped spring and the spring 50a are still in electrical and physical contact. Thus, a contact is made by means of the ground termination resistor 58 before the break or interruption of the signal path between the spring 50a and the spring 70. This sequence of operation is known as a sequence of "be done before the interruption". A communication plug made before the introduction is described in the aforementioned US patent 4,749,968 issued to Burroughs. After full insertion of the pin 33 into the hole 32 (Fig. 4), the free end of the spring 50a remains in electrical and physical engagement with the free end of the spring 42a and urges the spring 42a upwardly of the dielectric support 80. that the first termination contact 64 prevents further outward movement of the spring 70a, the electrical and physical connection between the spring 70 and the spring 50a is now interrupted. In addition, the downward predisposition of the spring 42a ensures continuous electrical and physical contact between the free ends of the springs 42a and 50a. By capturing the movable spring 50a between the posts 90b it is less likely that the vibration at which the plug 10 could be subjected during use causes an intermittent disconnection or other undesirable disconnection between the spring 50a and its desired connection with either the spring 70a or the pier 42a. As a result, the plug device 10 has the functional equivalence of the plug devices of the prior art. Mainly, with the absence of a plug in either of the holes 32, 34, the electrical connection between the rear center conductors 50, 52 is maintained. After the insertion of a plug plug to either one or the other of the plug holes, the electrical connection between the rear center conductors 50, 52 is interrupted and a new electrical connection of the rear center conductors 50, 52 to the front center conductors 42, 44 is established. The other rear center conductor is terminated through of resistance to an electrical ground connection. The plug device has the additional advantage that at no time is there a substantial length of the center conductor extending from the signal path as was the case with the prior art. That is, in the absence of a plug within the hole 32, the center conductor 42 and its associated spring portion 42a are electrically and physically disconnected from the rear center conductor 50. Accordingly, in high frequency applications, the center conductor 42 and its 42a dock portion does not deteriorate the signal. Also, at all times, the switching chamber 30 of the spring is substantially sealed from the exterior of the box 12. Accordingly, the passage of dust and other contaminants to the chamber 30 of the spring is resisted to minimize interference with the electrical connections within the chambers 30 of the spring. Also, the dielectric supports 80, 82, 84, 86 and needles or terminals 90b ', 92b' maintain the desired electrical contact or separation between the various springs in the mode of no plug insertion (Fig. 1) and in the mode of full pin insertion (Fig. 4) in the event that vibration forces act on the device 10. In the above description, the dielectric insertion parts 46, 48 were shown as cylindrical bodies that were solid throughout their volume. While such a design is functional, the present invention will preferably use a new design of a dielectric support. An example of such a new support is shown in Figures 9-15 as the dielectric insert 46 '. The insert 46 'provides the advantage that substantially all of the radial surfaces of the insert 46' are adjusted to a non-orthogonal angle with respect to the longitudinal axis of the central conductors 42, 44. With reference again to the figures 1 and 8, a cylindrical insert 46 having an axial face that is perpendicular to the axis of the center conductor 42 can result in an unsatisfactory return loss in an electromagnetic signal traveling along a coaxial transmission line such as the central conductor 42. That is, in a coaxial transmission line, an electromagnetic signal travels the line between the central and external conductors of a coaxial cable or between the central conductor 42 and the surrounding surfaces of the box 12 a external conductor that surrounds the central conductor 42. The signal propagates through any dielectric medium that is present between the conductors central and external bodies. For example, in a coaxial cable, the dielectric medium may consist of a plastic material positioned between the center conductor and the external grounding sleeve. Within a plug, the dielectric medium can be air filling a cavity between the center conductor 42 and the opposite surfaces of the box 12. As a result, there are different dielectric materials along the transmission line. Each time a signal passes from one dielectric medium to another, reflection occurs. An angle of incidence of a signal is the same as the angle of reflection. Accordingly, if a signal strikes a dielectric boundary that is perpendicular to the direction of travel of the signal, a portion of the electromagnetic energy will be reflected back in the opposite direction.

With the cylindrical configurations such as the inserts 46, 48, two surfaces are provided on the opposite axial ends of the inserts 46, 48 that are perpendicular to the direction of travel of the signal. Accordingly, such an insert produces two reflections that travel along the transmission line to a source. Other insulators of the prior art have a combination of solid dielectric material and air spaces to provide a composite effect of two dielectric coefficients in order to produce a specific impedance. Such insulators may have fins that extend radially from a center. However, such fins commonly have surfaces that are perpendicular to the direction of travel of the signal. Also, such insulators that include air spaces may also have a thin membrane of dielectric material that is perpendicular to the direction of travel of the signal in order to reasonably seal a device from dust or other contaminants. Such a membrane usually results in a significant impedance mismatch (that is, an impedance different from that of the rest of the transmission line) over the small thickness of the membrane. An impedance mismatch is undesirable since such mismatch is another source of reflection and also exhibits a loss of signal strength. The preferred insert 46 'includes a cylindrical outer wall 111 having a cylindrical outer surface 110 dimensioned to be received within the box in the wall 26 in the same manner as the inserts 46, 48. The insert 46 'includes a central hub 112 having a bore 114 extending axially to closely receive the central conductor 42. The hub 112 is conical in configuration and is supported by a plurality of ribs 116 extending radially between the conical hub 112 and a internal surface of the outer cylindrical wall 111. A first axial face 121 of the insert 46 'is shown in Figure 9. A reverse axial face 123 is shown in Figure 10. The reverse side 123 further includes a plurality of ribs 118 extending radially supporting the conical hub 112. The ribs 118 have opposite interior surfaces spaced apart to define additionally. s the perforation 114. The axial edges of the outer cylindrical body 111 are tapered to provide beveled faces 120. Similarly, the edges of all the ribs 116, 118 are tapered to provide beveled faces 122. Thus, substantially none of the surface areas either of the first or second axial ends 121, 122 is perpendicular to the axis XX of the insert 46 '. By substantially, it will be appreciated that the sharp knife edges on the tapered face 120, 122 can not be received in most molding processes. Thus, small dull areas 124 of the limitations in manufacturing processes can result. It is the purpose of the present invention that such surface areas be minimized as much as practical by means of manufacturing processes. With the embodiment shown in FIGS. 9-15, the complete axial face 121, 123 of the insert 46 'on both sides of the insert 46' has a non-orthogonal surface in relation to the travel path of the signal electromagnetic approaching the insert 46 '. As a result, the signal is not reflected axially of the insert 46 'to thereby reduce retroreflection. While the conical surface 112 may be curved, it would be preferable for the conical surface to be flat since a curved surface may reflect a signal in many different directions. However, the curvature may be acceptable in order to obtain a desired impedance matching in each cross section along the axial length of the insert 46 '.

Figures 16-19 show an alternative embodiment for an insert 46"having an outer cylindrical surface 110 'and a hub 112' defining a bore 114 '. The insert 46"is completely conical and does not include an external cylindrical wall nor does it include internal ribs to reinforce the structure of the insert 46". The embodiments of Figures 9-18 present a substantially closed surface after a central conductor is received in the perforations 114, 114 '. Such a closed surface can reduce the migration of dust beyond the insert 46 ', 46".While the prevention of dust migration is not required, the insert may have air cavities passing through it. the axial faces of the insert 1. Such insert is shown in Figures 20-25 where the insert 46 '' 'includes an outer cylindrical wall 111' '' with a cylindrical external surface 110"with axial ends beveled 120"and with inwardly protruding ribs 116" each having beveled axial ends 122". Opposite surfaces of ribs 116" define bore 114"for receiving the center conductor In all the modes shown, a surface not orthogonal is opposite to the signal path.The only portion that can be orthogonal is "a small resulting portion on the blunt edges of the beveled surfaces that may result from the manufacturing limitations. Having described the present invention in a preferred embodiment, it will be appreciated that modifications and equivalents of the described concepts can easily be presented to those skilled in the art. For example, while the preferred embodiment is shown with two front holes 32, 34, it will be appreciated that only one front hole 32 may be required. Also, as is conventional, a pre-verification circuit or verification plug may be connected to the plug 10 to allow non-intrusive verification of a signal. It will be appreciated that such verification plugs and the connection of verification plugs to coaxial switching plugs is well known. An example of such is shown in U.S. Patent Nos. 4,749,968 and 5,467,062 issued to Burroughs. Finally, the central conductors 42, 44 are shown solid in the drawings. For ease of manufacture, such conductors can be formed from a stamping or lamination process to produce a hollow tubular conductor. To resist migration of the powder, the thus formed conductor will preferably have a detent or tab projecting inwardly to present a blocking surface to the dust that would otherwise pass through the hollow central conductor. It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention is the conventional one for the manufacture of the objects to which it relates.

Claims (13)

1. Claims Having described the invention as above, the content of the following claims is claimed as property: 1. A coaxial switching plug device characterized in that it comprises: a first electrically conductive coaxial central conductor having a front or front portion and a rear portion; a second electrically conductive coaxial central conductor; the front portion and the rear portion include attachment ends of fixed front and rear positions respectively for attachment to a coaxial conductor; the second coaxial conductor has a fixed connection joint end for its connection to a coaxial conductor; the rear portion includes an electrically conductive movable portion that is movable between a first position and a second position while maintaining the electrical connection with the rear joining end; the movable portion is disposed in electrical contact with the second central conductor and electrically disconnected from the front portion when the movable portion is in the first position; the movable portion is disposed in electrical contact with the front portion and electrically disconnected from the second center conductor when the movable portion is in the second position and an actuator for moving the movable portion from the first position to the second position when a coaxial cable it is attached to the front union end.
2. 2. A coaxial plug device according to claim 1, characterized in that it comprises a box electrically connected to ground surrounding the first and second central conductors.
3. 3. A coaxial plug device according to claim 1, characterized in that it comprises termination means for electrically terminating the second central conductor through a ground resistance when the movable portion is in the second position.
4. 4. A coaxial plug device according to claim 3, characterized in that the termination means includes an electrically terminated contact; an electrically conductive switching spring in electrical contact with the second conductor, the commutator spring is urged to an electrical contact with the terminated contact and electrically disconnected from the movable portion when the movable portion is in the second position; the movable portion is positioned to be electrically connected to the second central conductor by means of the commutating spring with the movable portion which is electrically coupled to the commutating spring as the movable portion is moved to the first position and the commutator spring is driven from the finished contact by the movable portion moving to the first position. A coaxial plug device according to claim 4, characterized in that the finished contact, the switching spring, the front portion and the movable portion are mutually positioned so that the commutator spring is electrically coupled with the finished contact before the commutator spring is separated from the movable portion as the movable portion is moved to the second position. 6. A coaxial plug device according to claim 4, characterized in that the movable portion is first spring-loaded to the electrical contact with the commutator spring in the first position. A coaxial plug device according to claim 6, characterized in that the front portion of the first central conductor * includes a second spring with the first spring that engages the second spring and displaces the second spring against its custom-made predisposition that the first spring is moved to the second position. A coaxial plug device according to claim 1, characterized in that the actuator includes a lever having a cam end positioned to be displaced in response to the coaxial cable that is connected to the front attachment end; the lever has a second end arranged to drive the movable portion to the second position in response to the displacement of the cam end. A coaxial plug device according to claim 8, characterized in that the second end of the lever includes means for preventing the movable portion from moving relative to the second end. 10. A coaxial plug device characterized in that it comprises: a case having a rear end and a front or front end; the front or front end has at least a first plug hole for slidably receiving a plug having a pin or central terminal connected to an attached coaxial cable, a front center conductor disposed within the hole for receiving the needle or central terminal after the insertion of the plug into the hole; the rear end has at least a first coaxial connector and a second coaxial connector each having first and second rear center connectors respectively for connection to the central conductors of coaxial conductors attached to respective first and second coaxial connectors; the box includes walls for defining a sealed enclosed chamber of the first plug hole and the first and second coaxial connectors; a first front conductor connected to the central conductor and extending through the walls to the chamber and an insulator to electrically isolate the first front conductor from the box and to seal the chamber to resist the flow of particles from the first hole to the chamber; a first rear conductor connected to the first rear center conductor and extending through the walls to the chamber and an insulator to electrically insulate the first rear conductor from the box and to seal the box to resist the particle flow of the first coaxial connector after the camera; a second rear conductor connected to the second rear conductor and extending through the walls to the chamber and an insulator to electrically insulate the second rear conductor from the housing and to seal the chamber to resist the particle flow of the first rear coaxial connector to the camera; a lever extending through the walls with a cam end of the lever disposed outside the chamber and with a second end of the lever disposed within the chamber; the cam end is positioned to be displaced in response to a plug inserted into the first hole, the second end moves from a non-commutated position to a switched position in response to the displacement of the cam end; a switching circuit arranged within the chamber and including switching means for electrically connecting the first and second rear conductors and electrically separating the first front and rear conductors when the second end of the lever is in the non-switched position, the means The switching means further include means for electrically connecting the first front and rear conductors and electrically separating the first rear conductor and the second rear conductor when the second end of the lever is in the switched position and sealing means to resist the flow of more particles. Beyond the lever and the camera. A coaxial plug device according to claim 10, characterized in that the seal includes a pivot portion of the lever positioned within an opening in the walls and sized to substantially fill the opening. 12. A coaxial plug device characterized in that it comprises; a box having a rear end and a front or front end; the front or front end has at least a first plug hole for slidably receiving a plug having a central needle or terminal connected to an attached coaxial cable, a first front or front central conductor disposed within the first plug hole for receiving the needle or central terminal after the insertion of the plug of the first hole of the plug; the rear end has at least a first rear coaxial connector and a second rear coaxial connector, each having first and second rear center conductors respectively for connection to the central conductors of the coaxial conductors connected to the respective first and second coaxial connectors; a first electrically terminated contact; an electrically conductive switching spring in electrical contact with the second rear center conductor, the switching spring has a first end driven to an electrical contact with the finished contact; the first rear center conductor includes a first electrically conductive movable portion that is movable between a first position and a second position; the first movable portion is positioned to electrically couple with the first end of the commutating spring as the first movable portion is moved to a first position and the commutating spring is urged from the finished contact by the movable portion moving to the first position; the first movable portion is arranged in electrical contact with the first front central conductor and electrically disconnected from the first end of the switching spring when the movable portion is in a second position; a first lever having a cam end positioned to be displaced in response to the plug inserted into the first front hole; and the lever has a second end arranged to drive the first movable portion to the second position in response to the displacement of the cam end. A coaxial switching plug according to claim 12, characterized in that it comprises: a second plug hole for slidably receiving a plug having a central needle or terminal connected to an attached coaxial cable, a second central front conductor arranged inside the second plug hole to receive the central pin after the insertion of the plug into the second plug hole; a second electrically terminated contact; the switching spring has a second end driven to an electrical contact with the second terminated contact; the second rear center conductor includes a second electrically conductive movable portion that is movable between a first position and a second position; the second movable position is arranged in electrical contact with the second end of the switching spring and electrically disconnected from the second front center conductor when the second movable portion is in the first position; the second movable portion is positioned to electrically couple with the second end of the commutating spring as the second movable portion is moved to a first position and the second end of the commutating spring is driven from the second terminated contact by the second movable portion that moves to the first position; the second movable portion is arranged in electrical contact with the second leading central conductor and electrically disconnected from the second end of the switching spring when the second movable portion is in a second position; a second lever having a cam end positioned to be displaced in response to the plug inserted into the second front hole; and the second lever has a second end arranged to drive the second movable portion to the second position in response to the displacement of the cam end.