GB2199197A

GB2199197A - A coaxial cable connector male plug

Info

Publication number: GB2199197A
Application number: GB08727307A
Authority: GB
Inventors: Georg Spinner
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-11-25
Filing date: 1987-11-20
Publication date: 1988-06-29
Also published as: FR2607328A1; GB8727307D0; IT8722589A0; IT1223095B; DE3640167A1; DE3640167C2

Abstract

A coaxial cable connector male plug or N-plug with improved stability of its inner conductor pin has an outer conductor part 2 whose leading end forms a cylindrical contact sleeve 5 which contains the inner conductor pin 7. On the cable side of the pin 7, the pin is located in an insulating support sleeve 8, which extends in the outer conductor contact sleeve 5 up to an inner conductor junction plane I. <IMAGE>

Description

A COAXIAL CABLE CONNECTOR MALE PLUG This invention relates to a coaxial cable connector male plug of the type commonly termed an N-plug. N-plugs have long been known and have main dimensions as defined by MIL standard C 39012.

Such a known plug has an annular outer conductor part carrying a rotatable securing nut and provides at its leading end a cylindrical contact bush for engagement with part of a cable connector female socket. An inner conductor pin extends in the bush almost to the outer conductor junction plane. An insulating sleeve in the form of a disk is arranged in a casing of the plug at the end of the cable reception area. This inner conductor pin is held in self-supporting manner by the disk and has a diametral step level with the inner conductor junction plane, which is set back by approximately 4 to 5 mm in the outer conductor bush from the outer conductor junction plane.Thus in the case of incorrect handling of the plug, the inner conductor pin can be displaced out of its axial position or bent back on itself, whilst a separate working process is required during the manufacture of the inner conductor pin to produce the diametral step.

There is thus a need for a generally improved coaxial cable connector male plug whose inner conductor pin preferably is of simplified manufacture, preferably has a reliable central position in the outer conductor sleeve and preferably is of reduced sensitivity to mechanical stressing.

According to the present invention there is provided a coaxial cable connector male plug including an annular outer conductor part having a reduced diameter leading end portion forming a cylindrical contact bush for engagement with part of a cable connector female socket, a rotable securing nut mounted on the outer conductor part and extending around the outer conductor part leading end portion, an inner conductor pin extending coaxially in the outer conductor part almost to the outer conductor junction plane located at the open leading end of the contact bush, and an insulating support sleeve engaged in the outer conductor part and extending in the contact bush as far as the inner conductor junction plane, with the inner conductor pin extending through and being supported by the insulating support sleeve.

Thus, in the same way as a known N-plug, a coaxial cable connector male plug of the invention satisfies the aforementioned MIL standard, but permits the use of an inner conductor pin with a constant diameter throughout (except for its tapered nose), because on choosing a dielectric having an appropriate relative dielectric constant as the material for the insulting support sleeve the characteristic impedance reduction brought about by the latter can just be compensated for by reducing the diameter of the inner conductor pin to the value of the latter between the inner conductor junction plane and its end. Since over a considerable part of its length, the inner conductor pin extends in the insulating support sleeve, it is positioned precisely centrally and is of reduced sensitivity to bending stresses.

Moreover, that part of the insulating support located in the cable reception area can be shortened to a collar acting as an axial abutment, so that the axial length of the plug is correspondingly reduced.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made to the accompanying drawings, in which the single Figure 1 shows in longitudinal part section a coaxial cable connector male plug according to an embodiment of the present invention.

In the accompanying drawings Figure 1 shows a coaxial cable connector male plug or N-plug of the invention having a casing 1, which electrically forms an outer conductor part 2 and carries a rotatable securing nut 3 mounted on the part 2 with an inner retaining ring 4. The outer conductor part 2 has a reduced diameter leading end portion forming a cylindrical central contact bush 5, which is slotted four times in the axial direction, as can be seen at 5a. The cylindrical contact bush 5 carries a seal 6 and is operative to engage part of a cable connector female socket (not shown). The plug contains an inner conductor pin 7 extending coaxially in the part 2. A cable-side part 7a of the pin 7 has a diametral step 7b, which serves as a stop face and with which the inner conductor pin 7 engages against the cable-side face of an insulating support sleeve 8.The sleeve 8 extends in the cylindrical contact bush 5 up to an inner conductor junction plane I, whose position relative to an outer conductor junction plane A is standardized. Only the diameter of the inner conductor pin 7 in its portion to the front or right of the inner conductor junction plane I in Figure 1 is standardized.

The dielectric constant of the insulating support sleeve 8 is chosen in such a way that in the case of a constant diameter d of the inner conductor pin 7, there is no characteristic impedance jump at the location ofthe insulating support sleeve. To obtain a constant characteristic impedance, a radial step 2a is provided at the transition of the outer conductor part 2 into the cylindrical contact bush 5 roughly level with the diametral step between the cable-side part of the inner conductor pin 7 and its plug-side part.

The construction of the insulating support sleeve 8 also has the advantage that the axial length of the plug is reduced, because that part of the insulating support sleeve 8 located in the cable reception bore 10 can be kept very short, whereas in known N-plugs the disk-like insulant support has been entirely received within the cable reception bore, which had to be correspondingly longer. To this end the sleeve 8 has an enlarged diameter portion at its trailing end forming an axially narrow collar 8a. This collar 8a only of the sleeve 8 extends into the complementary diameter cable reception bore 10 in the trailing end portion of the part 2.

Claims

1. A coaxial cable connector male plug including an annular outer conductor part having a reduced diameter leading end portion forming a cylindrical contact bush for engagement with part of a cable connector female socket, a rotable securing nut mounted on the outer conductor part and extending around the outer conductor part leading end portion, an inner conductor pin extending coaxially in the outer conductor part almost to the outer conductor junction plane located at the open leading end of the contact bush, and an insulating support sleeve engaged in the outer conductor part and extending in the contact bush as far as the inner conductor junction plane, with the inner conductor pin extending through and being supported by the insulating support sleeve.

2. A plug according to claim 1, wherein the insulating support sleeve has an enlarged diameter portion at its trailing end forming an axially narrow collar, which collar only of the sleeve extends into a complementary diameter cable reception bore formed in the outer conductor part in a trailing end portion of the outer conductor part.

3. A plug according to claim 1 or claim 2, wherein the inner conductor pin has a constant diameter over the major part of its length.

4. A coaxial cable connector male plug, substantially as hereinbefore described and as illustrated in Figure 1 of the accompanying drawings.