A plug for connection to an rca or phono type socket

0001This invention relates to a plug for connection to an RCA or phono type socket.

0002This invention has particular but not exclusive application to audio electrical connections, and for illustrative purpose reference will be made to such application.

0003The RCA plug and socket connection system (a generic name for a phono type plug and socket connection system) has been criticized by electronic engineers and audio enthusiasts as being an inferior connection for high quality audio. The RCA plug and socket connection system was originally designed as a means of connecting antenna cables to televisions. It was never considered the best solution for audio applications but has become the de facto world standard plug and socket connection system as used in consumer electronic components worldwide; see e. g. <patcit id="pcit0001" dnum="US5222149A"><text>US-A-5 222 149</text></patcit>.

0004The RCA plug is prone to capacitive and oxidative effects because of the poor fitting of some plug designs and due to the wide-ranging size of RCA sockets (7.95mm to 8.55mm diameter). It is also believed that the large amount of metal used in the construction of many RCA plugs is a cause of inductive and capacitive distortion, which in turn adversely affects sound reproduction.

0005Additionally, the cylindrical conductive band connection system used in typical RCA plugs to surround and make contact with the outer casing of an RCA socket tends to disperse the flow of electrons. As a result the transmitted current flows through many different entry points, resulting in interfering eddy currents and consequent distortion.

0006Extensive listening tests reveal that most RCA plugs, including many expensive audiophile varieties, slow the flow of electrons and add coloration to the music signal. This is why many audio enthusiasts by-pass connections by "hard wiring" cables that connect audio equipment, thereby eliminating the deficiencies associated with the use of RCA plug and socket connectors.

0007It is the object of the present invention to alleviate the above disadvantages and to provide a plug for connection to an RCA socket which will offer better sound and will be reliable and efficient in use.

0008This object is attained by the features of claim 1. An advantageous embodiment of the invention is defined in the subclaim. For example, the retaining means may include a spring that urges the return conductor towards the casing. Alternatively, the retaining means may include a recess having a continuous side wall, or a plurality of circumferentially spaced wall portions, which support the return conductor and retain the return conductor in contact with the casing when an end portion of the casing is frictionally located within said recess. The side wall of the casing may further include one or more breaks formed therein that allow the recess to engage sockets that exhibit minor variations in respect of the external diameter of the casing.

0009The main difference between the present invention and prior art is the incorporation of said return conductor in the form of a pin, as opposed to the typical cylindrical conductive band, to engage the outside casing of an RCA socket.

0010In the present invention the return conductor in the form of said pin makes contact with the outside casing of an RCA socket by means of a raised contact area at the front portion of the pin that may include but is not limited to shapes such as an ellipse, a sphere, a cylinder etc.

0011One advantage of the return conductor of the present invention is the fact that it comprises far less conductive metal material than the return conductor embodied in a typical RCA plug, thereby reducing distortion.

0012The return conductor may be constructed from a variety of electrically conductive materials, such as various brass, nickel, silver and copper alloys. The return conductor may also include at least one site along its length where the free end of an electrical wire may be soldered thereto. For example, the trailing end portion of the return conductor may include a seat extending rearwardly therefrom.

0013The signal pin may also be constructed from a variety of electrically conductive materials, such as various brass, nickel, silver and copper alloys.

0014The signal pin may be of solid or hollow construction. For example, the signal pin may be tubular and generally of constant transverse cross-section.

0015The signal pin may include at least one site along its length where the free end of an electrical wire may be soldered thereto. For example, the trailing end portion of the signal pin may include a seat extending rearwardly therefrom.

0016Selected portions of the signal pin, return conductor and spacing means may be enclosed within a housing that may be constructed from a variety of materials including various electrically non-conductive materials and heat resistant materials, such as plastic polymer and Teflon materials.

0017The housing may be provided with one or more apertures therein through which electrical wires and/or cable may extend and whereby in use the housing may provide protection for the connections between the wires and the signal pin and the return conductor.

0018In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein: <ul id="ul0001" list-style="none"><li><figref idref="f0001">FIGURE 1</figref> is a longitudinal cross-sectional side view of a plug that is constructed in accordance with the present invention, the plug being adapted for connection to an RCA socket;</li><li><figref idref="f0001">FIGURE 2</figref> is a longitudinal cross-sectional isometric view of the plug illustrated in <figref idref="f0001">Figure 1</figref>;</li><li><figref idref="f0002">FIGURE 3</figref> is an isometric front view of the plug illustrated in <figref idref="f0001">Figure 1</figref>, shown with the housing removed;</li><li><figref idref="f0002">FIGURE 4</figref> is a side view of the plug illustrated in <figref idref="f0001">Figure 1</figref>, shown with the housing removed;</li><li><figref idref="f0003">FIGURE 5</figref> is an isometric front view of the plug illustrated in <figref idref="f0001">Figure 1</figref>, shown with housing removed, and showing the means by which the plug makes contact with an RCA socket;</li><li><figref idref="f0003">FIGURE 6</figref> is a typical RCA socket.</li><li><figref idref="f0004">FIGURE 7</figref> is a longitudinal cross-sectional isometric view of the plug illustrated in <figref idref="f0001">Figure 1</figref> when operatively connected to an RCA socket, and showing an electrical cable operatively connected thereto;</li><li><figref idref="f0004">FIGURE 8</figref> is a longitudinal side view of the plug illustrated in <figref idref="f0001">Figure 1</figref> when operatively connected to an RCA socket, and showing an electrical cable operatively connected thereto;</li></ul>

0019<figref idref="f0004">Figures 7 and 8</figref> show longitudinal cross-sectional views of a plug 10 that is operatively connected to an RCA socket 11 having an external casing 12, that is constructed from an electrically conductive material, and an internal bore 13, that is also lined with an electrically conductive material, said casing 12 and said bore 13 being separated from each other by suitable insulation 14.

0020The plug 10 includes a signal pin 15 that is frictionally locatable within the bore 13, a return conductor 16 which makes electrical contact with the casing 12 when the signal pin 15 is located within said bore, and spacing means 17 that maintains said signal pin 15 and said return conductor 16 in an operative spaced relationship.

0021The signal pin 15 is constructed from a suitable electrically conductive material, such as various brass, nickel, silver or copper alloys. The signal pin 15 consists of a cylindrical tube having a bore 15a of constant transverse cross-section and a rearwardly extending, channel shaped seat 18.

0022The return conductor 16 consists of a cylindrical pin constructed from a suitable electrically conductive material, such as various brass, nickel, silver or copper alloys, and includes a rearwardly extending, channel shaped seat 19.

0023The spacing means 17 is constructed from an electrically non-conductive material, such as plastic polymer or Teflon. The spacing means 17 includes a generally cylindrically shaped head portion 20 having an axially located, cylindrically shaped recess 21 that is defined by a substantially continuous internal side wall 22. The side wall 22 includes four equally spaced splits 23 that allow partial relative movement of the constituent wall portions 24 thereby enabling the recess 21 to frictionally receive a variety of RCA sockets 11 each having a cylindrically shaped end portion 25 of differing external diameter. The head portion 20 also includes a centrally located, longitudinally extending through bore 26, formed in an intermediate base wall 26a through which a portion of the signal pin 15 extends.

0024The signal pin 15 includes a holding lug 35 which protrudes perpendicularly from a position along the length of signal pin 15 to support and prevent movement of signal pin 15 within spacing means 17.

0025The return conductor 16 includes a holding lug 36 which protrudes perpendicularly from a position along the length of return conductor 16 to support and prevent movement of return conductor 16 within spacing means 17.

0026The return conductor 16 extends through an aperture 40 formed in the base wall whereby an elliptical shaped contact portion 41 of the return conductor 16 lies flush with, and protrudes marginally from the internal side wall 22 to make contact with the cylindrically shaped end portion 25 of an RCA socket.

0027The plug 10 also includes a cylindrically shaped, tubular housing 29 which is partially closed at one end by rear wall 30 which is provided with a centrally located aperture 31.

0028In use, the free end of a piece of cable 32 containing two or more electrical wires 33 and 34 is threaded through the aperture 31 prior to the placement of the housing 29 in it's operative position whereby it shrouds the rearward portions of both the signal pin 15 and the return conductor 16. The cable 32 is secured by use of grub screw 27 located through aperture 28 thereby making contact with the outer sleeve of appropriately sized cable 32.

0029The free exposed end portion 37 of the signal wire 33 may be supported by the seat 18, as illustrated in <figref idref="f0001">FIGURES 1 and 2</figref>, and subsequently connected thereto using a suitable electrical solder. Alternatively, the free exposed end portion 37 of the signal wire 33 may be extended through the bore 15a and subsequently soldered to a side wall of said bore adjacent to the tip 38, as illustrated in <figref idref="f0004">FIGURES 7 and 8</figref>.

0030The free exposed end portion 39 of the return wire 34 may be supported by the seat 19, as illustrated in <figref idref="f0001">FIGURES 1 and 2</figref>, and subsequently connected thereto using a suitable electrical solder.

0031When the plug 10 is operatively connected to an RCA socket 11, the signal pin 15 is frictionally located within the bore 13 and the contact portion 41 of the return conductor 16 bears against and thereby makes electrical contact with the adjacent casing 12 as illustrated in <figref idref="f0004">FIGURES 7 and 8</figref>.

0032When using the plug 10 with an appropriate audio cable, and in comparison to the same audio cable terminated with a standard RCA plug, it is believed that the sound quality is greatly enhanced. This appears to be due to enhanced electron flow within the plug as a result of diminished capacitive and inductive reactance.

0033It will of course be realised that the above has been given only by way of illustrative example of the present invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope of this invention as defined in the appended claims.