Connector plug

A connector plug for connection at the end of a cable comprises a plug body of conductive material having a generally tubular common connector extending from an end thereof and integrally formed therewith, and a hole for receiving the end portion of the cable. The common contactor has a substantially central hole extending therethrough and a hot contactor is attached at one end of the common contactor electrically insulated from the common contactor. A connecting member is disposed in the central hole of the common contactor and has one end which is electrically connected to the hot contactor and another end which is located in the interior of the cable receiving hole of the plug body. The connecting member has a receiving portion with an axially extending receiving hole for receiving the tip of one of the conductors of the cable therein. An insulating cap is provided to cover the plug body.

BACKGROUND OF THE INVENTION 
This invention relates to a connector plug for coaxial cables used for 
electrical connection between electrical equipment such as components of 
audio systems. 
A conventional connector plug attached to the end of a coaxial cable 
comprises a common contactor integrally formed at the tip end of a plug 
body and a hot contactor fitted at the end of the common contactor and an 
insulating member placed between the contactors. A connecting member or 
rod penetrating through the common contactor is connected at its one end 
to the hot contactor and has a connecting portion at the other end to 
which is connected one of the conductors of the cable. The oher conductor 
is connected to the plug body directly. 
In the known connector plug the connecting member has a shape of a simple 
rod so that it is difficult to determine the correct position on the rod 
shaped connecting member to which the conductor of the cable is to be 
connected by soldering. Also, this construction does not give a secure 
connection therebetween. This results in disconnection of the conductor 
from the rod due to any shock or the like and in short circuiting between 
both conductors of the cable. 
SUMMARY OF THE INVENTION 
The object of this invention is to provide an improved connector plug in 
which disconnection of the conductor of a cable and short circuiting of 
the conductors of the cable are prevented. 
Therefore, it is an object of this invention to provide a connector plug 
having a secure connection to the cable conductors. 
Another object of this invention is to provide a connector plug having 
means for securely retaining a cable to the plug, thereby preventing 
disconnection of the conductors even when the cable is pulled from the 
plug.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIG. 1, the reference numeral 1 generally designates a 
tubular plug body of conductive material, one end of which is provided 
with an opening 3 into which a coaxial cable 2 is inserted. The other end 
of the body 1 is integrally formed with a tubular portion or common 
contactor 4 having a smaller diameter than the body 1 and extending from 
the body 1. A hot contactor 6 is securely fitted at the tip end of the 
common contactor 4, between which is positioned an insulating member 5 to 
provide electrical insulation between the common contactor 4 and hot 
contactor 6. 
In the central hole or opening 3 of the plug body 1 and the central 
elongated opening of common contactor 4 is placed an elongated connecting 
member 7 having portions 7a and 7b. The portion 7b penetrates through the 
central hole 3 of the contactor 4 and is electrically connected at one end 
to the hot contactor 6. The other portion 7a is positioned in the interior 
of the hollow body 1 and has at one end a hole 7c into which the tip of 
conductor 2a of the cable 2 is inserted and electrically connected thereto 
by an amount of solder 9. Another conductor 2b of the cable 2 is 
electrically connected to the body 1 by an amount of solder 10. As a 
result, the conductors 2a and 2b are electrically connected to the hot 
contactor 6 and common contactor 4, respectively. In order to facilitate 
making the electrical connections, there is provided an opening 8 in the 
side wall of the plug body 1. The structure of the connection of the 
member 7 and the conductor 2a is illustrated in FIG. 2 more in detail. 
One of the major advantages obtained through the construction of this 
invention is that the operation of making the connection between 
connecting member 7 and the conductor 2a of the cable 2 is facilitated. 
Such connection can be made by inserting the tip of the conductor 2a into 
the hole 7c of the receiving portion 7b and then soldering them to make an 
electrical and mechanical connection. The hole 7c will serve as a guide to 
insert the tip of the conductor 2a. Preferably, the portion 7a of the 
member, as shown in FIG. 6, may be cut out to form a lip 7d which aids to 
easily insert the tip of the conductor 2a of the cable 2 as well as 
facilitates to cause an amount of molten solder to flow into the hole 7c. 
Furthermore, a tubular cap 11 of an insulating material is attached so as 
to cover the peripheral surface of the body 1 and is securely fixed in 
position by means of a screw 12. Alternatively, a cap 21, as shown in FIG. 
3, may be secured by means of threads 13 and 14 formed on the body 1 and 
the cap 21, respectively. The latter arrangement is convenient in the 
sense that the attaching and detaching operation of the cap can easily be 
performed and there is no fear of losing the fitting screw 21. 
FIGS. 4, 5A and 5B illustrate a modified connector plug embodying this 
invention. As clearly shown in FIG. 5A, the plug body 1 is provided with 
an end portion having a plurality of slits 1a, each of which axially 
extends from the end of the body 1 to form flexible portions which are 
inwardly movable. A thread lb formed on the peripheral surface of the slit 
end portion is provided for engagement with a thread 14 formed on the 
inner surface of the cap 31 by inserting the body 1 into the central hole 
of the cap and turning it in a predetermined direction. The cap 31 has at 
its rearmost end a flange 31a extending inwards. The flange 31a will press 
the flexible portions at tapered surfaces 15 formed at the rearmost end of 
the body 1 when the body 1 is forcedly screwed into the cap 31, resulting 
in decreasing in the diameter of the end of the body 1 to tighten against 
the cable penetrating through that portion of the body. In this state the 
cable 2 can not move in the axial direction and also can not rotate around 
its axis relative to the plug. 
In the embodiment shown in FIG. 4, an insulator tube 16 is placed in the 
space between the common contactor 4 and the connecting member 7. The 
insulator tube 16 has a flange portion 16a at an end thereof which is 
disposed in the interior of the body 1 and hold the free end 7a of the 
connecting member 7 in position. 
In FIGS. 7 and 8 is shown another connector plug embodying this invention 
which has a modified cap. Namely, the cap 41 utilized in this embodiment 
comprises two parts 41a and 41b. The part 41a of the cap is shaped in a 
tubular form and has a thread 42 at one end thereof for engagement with 
the thread lb of the body 1. The second part 41b of the cap is also 
shaped in a tubular form and has a thread 17 on the inner surface thereof 
and a flange 43 of the same type as flange 31a of the embodiment shown in 
FIGS. 4 and 5B. The first and second parts 41a and 41b of the cap are 
screwed on from the opposite sides of the body 1 so as to cause the 
threads 42 and 17 to engage with the same thread lb on body 1. 
According to the embodiment shown in FIGS. 7 and 8, the operation for 
connecting the cable to the plug comprises screwing the part 41b to the 
body 1 and then attaching the part 41a after the respective connection of 
the conductors 2a and 2b to the member 7 and body 1 has been made. 
Therefore, the cable will not be twisted during the operation of attaching 
the cap 41 to the body 1.