US 3626360 A
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Description (OCR text may contain errors)
United States Patent  inventor James Edward George Cole Ansty, England  Appl. No. 882,458
 Filed Dec. 5, 1969  Patented Dec. 7, 1971  Assignee Rendar Instruments Limited  Priority Dec. 9, 1968 Great Britain  ELECTRICAL CONNECTORS 6 Claims, 7 Drawing Figs.
[5l] lnt.Cl  Field otSearch  References Cited UNITED STATES PATENTS 1,535,451 4/1925 Cohen 1,639,858 8/1927 Potter 1,837,723 l2/l93l McGraw Primary ExaminerMarvin A. Champion Assistant Examiner- Lawrence J. Staab Attorney-Lawrence E. Laubscher 339/l83X 339/l83 X 339/183 X ABSTRACT: A jack plug having at least three contacts of the tip, ring and sleeve type in which the separate conductors from the contacts are brought into a bush in the head of the plug which is formed to divide by lobes the space in the head into radially extending regions, a separate conductor being located in each region. This prevents the separate conductors making undesired electrical contact with each other.
PATENTED mm mm 3.626860 sum 1 [1F 2 FIG 4. 5M
' INVENTOR Y M I! M 4- ATTORNEY PATENTED nee mm 36263360 sum 2 or 2 FIGS.
jmes 5.6 ola INVENTOR WFM ATTORNEY ELECTRICAL CONNECTORS This invention relates to electrical connectors and is more specifically concerned with a construction of a jack plug of the tip, ring and sleeve type. The invention is particularly concerned with a construction of such a jack plug and is particularly suitable for jack plugs of miniature size.
It is necessary to make electrical connections to a jack plug and this is usually done by connecting wires to conductors located in the head of the plug and which are connected respectively to the several contact portions of the plug. When the plug is of the miniature kind the conductors may be very close together and this is particularly the case when the plug is provided with three, or even more, contacts. There is then a considerable risk that the attached wires will short circuit the various conductors. It is also difficult to solder wires to the conductors without making a single connection to more than one conductor.
It is an object of the invention to provide a jack plug in which this difficulty is overcome.
According to the invention there is provided a jack plug comprising a. a tip contact,
b. at least one ring contact,
c. a sleeve contact,
d. a rod conductor integral with said tip contact,
e. at least one inner hollow cylindrical conductor integral with a respective said ring contact,
f. an outer hollow cylindrical conductor integral with said sleeve contact,
g. insulating means separating the respective contacts ans associated conductors,
h. a lobed bush formed of insulating material and having a center bore along its axial length, the lobes of said bush defining a number of radially extending regions equal in number to the number of conductors one of said regions extending into the center bore,
. a conductive connector located in each of said regions, each connector being integral with a respective conductor, wherein the connector integral with the rod conductor is located in the center bore of said brush, such that all connectors are accessible for connection to an external wire from a radial direction.
Features and advantages of the invention will appear from the following description of an embodiment thereof, given by way of example, in conjunction with the accompanying drawings, in which:
FIG. 1 is a longitudinal section through a miniature jack P g:
FIG. 2 is a view from one end, of an insulating bush incorporated in the jack plug of FIG. 1
FIG. 3 is a sectional view of the bush of FIG. 2 taken on the line 3-3 of that Figure;
FIG. 4 is an end view, from the opposite end, of the same bush; and
FIGS. 5 to 7 are perspective views of said bush as seen respectively from three directions.
The jack plug shown comprises a tip contact 10, ring contact 11 and a sleeve contact 12. The jack plug is intended to be used with a corresponding jack socket, having three axially spaced contacts.
The sleeve 12 is a turned member of metal and at its rearward end has a cylindrical portion 120, extemally screwthreaded at 12b, this portion terminating at a flange 13. A cylindrical cover member of which part is shown at 14, and conveniently of metal, can be screwed onto the threaded portion of the sleeve. In the usual way, the cover member may have in its free end an opening for the entry of the cable or wires to be connected. The cylindrical contact making surface 120 of the sleeve may be plated with a contact metal, such as silver.
The ring contact 11 is formed integrally with or has attached to it a tubular part 15. This part is of a length sufficient to extend through to the cylindrical part 12a of the sleeve, and its extremity has attached to it a terminal lug 17 for connection to the ring. Any suitable means can be adopted for joining the lug to the tubular part 15, but conveniently the two parts can be hot tinned, and subsequently joined by heating the two parts whilst in contact.
The third contact member of the jack, the tip 10, is formed integrally with or has attached to it a central stem portion 18, which extends rearward beyond the end of the portion 12 of the sleeve. The end of this stem affords a means of making connection to the tip, Connection to the sleeve is made by means of a terminal lug 20; this is formed integrally with an annular part 21 which fits within the cylindrical portion 12a of the sleeve. The annular part 21 is attached to the interior of the cylindrical part of the sleeve by any suitable means, but conveniently by the hot tinning and heating treatment described above.
The three contacts of the jack must be kept in insulated relationship and this is effected by an insulating bush 22 and by insulating material, as at 23, which is moulded between the parts. The bush 22 is shown in more detail in FIGS. 2, 3 and 4, and in perspective views in FIGS. 5, 6 and 7. The bush has a cylindrical outer surface portion at 22 a which is of a diameter to fit within the cylindrical portion 12a of sleeve 12. Adjacent this surface is a portion of slightly reduced diameter, at 2211, upon which can fit the annular part 21 attached to terminal tag 20. As will be seen from FIG. 1, the axial length of the surface 22b, is somewhat less than the axial length of the annular part 21. The cylindrical surface 22a is interrupted by a grove or radially extending region which is to accommodate the terminal tag 20.
The bush also has a stepped recess 22d at its forward end, and from this recess there extends a longitudinal arcuate slot 22c, of a size to receive the terminal lug 17 attached to the tu bular part 15 of the ring contact. The slot 22 e is positioned so as to communicate with the inside edge of a recess or radially extending region 22f having as its cross section a sector of an annulus, into which the lug 17 will extend when the parts are assembled. Also, the bush is formed with a central opening 22g which receives the stem 18 of the tip contact and this opening breaks into a further arcuate recess or radially extending region at 22/1.
As a result of this construction of the bush, it will be seen that the terminal lug 17 is accommodated in a recess, as is the terminal portion of the stem 18. This enables electrical connection of an external wire to be made as by soldering, from a radial direction, conveniently and with minimum danger of electrical short circuit being created between the contacts. As will be seen from FIG. I, the lug 20 of the sleeve contact extends from the bush so that connection can be similarly made to this lug.
In making the jack plug, the three contact members and the bush can be assembled in the relative positions shown in FIG. 1. So assembled, the parts can be located in a suitable mould, by which the forward parts of the three contact members will be held in suitable spaced disposition. Insulating material, such as polystyrene, can then be injected into the spaces between the three contacts, forwardly of the bush, as shown in FIG. 1. To locate the tip contact more conveniently in the mould, it may be formed with a flange, as at 100.
The construction described enables miniature tip ring and sleeve jack plugs to be made which are satisfactory in operation, and convenient in use, in that the necessary connections can be made to the parts of the jack plug with minimum danger of short circuits or faulty connections. The construction'has proved satisfactory for miniature jack plugs having the standard diameter of 3.5 mm.
What is claimed is:
1. A jack plug for at least three external wires comprising a. a tip contact;
b. at least one ring contact;
c. a sleeve contact;
d. a rod conductor integral with said tip contact;
e. at least one inner hollow cylindrical conductor integral with a respective said ring contact;
. an outer hollow cylindrical conductor integral with said sleeve contact;
g. insulating means separating the respective contacts and associated conductors;
h. a lobed bush formed of insulating material and containing a center bore along its axial length, the lobes of said bush defining a number of radially extending regions equal in number to the number of conductors, one of said regions extending into the center bore;
i. a conductive connector located in each of said regions,
each connector being integral with a respective conductor, wherein the connector integral with the rod conductor is located in the center bore of said bush, such that all connectors are accessible for connection to an external wire from a radial direction.
2. A jack plug according to claim 1 in which the connector integral with the sleeve conductor is a tap parallel to longitudinal axis of the plug and passes along a groove formed in the side of said bush.
3. A jack plug according to claim 2 in which there is provided a hollow cylindrical conductive portion between said outer cylindrical conductor and said tab having a greater diameter than said outer cylindrical conductor one end of said bush being inserted therein.
4. A jack plug according to claim 3 in which said conductive portion is threaded on its outer surface for the attachment of a 5. A jack plug according to claim 1 in which the insulating means is an injection moulding.
6. A jack plug comprising a tip contact;
. at least one ring contact;
a sleeve contact;
a rod conductor integral with said tip contact; at least one inner hollow cylindrical conductor integral with a respective said ring contact; an outer hollow cylindrical conductor integral with said sleeve contact; insulating means separating the respective contacts and associated conductors;
a lobed bush formed of insulating material, said lobes defining a number of radially extending regions equal in number to the number ofconductors;
. a conductive connector located in each of said regions; I conductive connections from each of said connectors to a respective conductor;
a connector integral with a said inner cylindrical conductor is a tab parallel to the axis of said plug ans has a cross section in the form of an arc of a hollow cylinder, and passes through a slot in said bush.