US3340491A - Electrical socket connectors and other electrical contact devices - Google Patents

Description

Sept. 5, 1967 s. T DEAKIN 3,340,491 ELECTRICAL SOCKET CONNECTORS AND OTHER ELECTRICAL CONTACT DEVICES Filed April 17, 1964 2 Sheets-Sheet 1 INVENTOR. STAN LEY THOMAS DEAKI N yQmZ i 4 HIS ATTORNEY.

Sept. 5, 1967 s. T DEAKIN 3,340,491

ELECTRICAL SOCKET CONNECTORS AND OTHER ELECTRICAL CONTACT Filed April 17, 1964 DEVICES 2 Sheets-Sheet I 4 -I II INVENTOR STAN L EY THOMAS DEA KIN BY 4 K dodg HIS ATTORNEY.

United States Patent 3 340 491 ELECTRICAL SOCKEFCOIVNECTORS AND OTHER ELECTRICAL CONTACT DEVICES Stanley Thomas Deakin, Walton-on-Thames, Surrey, Eng- 7 The invention relates to electrical socket connectors, plug, switches and other electrical contact devices of the kind having a body (e.g. of plate or disc form) of insulating material carrying at least one electric contact which, in use, makes pressure or sliding engagement with a co-operating contact. The invention is particularly, but not exclusively, concerned with electrical socket connectors of the kind having a support body or plate of insulating material, a plurality of sockets in the support body for receiving the pins or wires of a transistor, valve or other electrical plug, each socket having means for making an electrical connection with the pin or Wire. The invention is especially applicable to such devices of small size. The invention also relates to a method of making such devices.

It is an object of the invention to provide various improvements in devices of the above kind and in the manufacture thereof.

The invention provides an electrical contact device of the above kind in which the contact is provided by a metallic coating on the body.

The device may have a separately constructed resilient contact secured to the body and opposed to the coated contact to receive and grip betweenthem a separating con-tact. Preferably the resilient contact is welded or soldered to a metallic coating on the body which may be a part, or an extension, of the coated contact.

When the invention is applied to a socket connector,

the body may be of glass with a socket or sockets etched therein and coated with metal to provide socket contact surfaces.

The invention also provides the method of making an electrical socket connector which comprises the steps of exposing to light selected portions of a body of photosensitive glass to render the body more readily soluble by etching acid in the region where a socket is required, etching the body to form the socket and coating with metal the internal surface of the socket and an area of the external surface of the body extending from the mouth of the socket.

The photo-sensitive glass used is preferably of the kind in which the etching rate of exposed portions is greater than the etching rate of unexposed portions or vice versa and it may be of the kind sold by the Coming Glass Works under the trade name Fotoform. After the sockets have been formed, the glass may be converted to its ceramic form. The exposure may be eflected through a negative, or a positive, of the desired socket pattern.

The invention further provides the method of making a multi-socket electrical socket connector which comprises the steps of exposing to light selected portions of a body of photo-sensitive glass to render the body more readily soluble. by etching acid in the regions where sockets are required, etching the body to form the sockets, forming on the body metallic coatings lining the sockets and extending from the sockets individually over portions of the external surface of the body, welding or soldering to the coatings on the'external surface of the body a sheet metal unit shaped to comprise a multiplicity of resilient contacts, one for each socket, joined together by narrow ties, inserting portions of the contacts into the sockets and cutting the ties to separate the cont-acts.

Patented Sept. 5, 1967 The metal coating may be applied by the techniques ware) and it may be applied to the whole surface of the body and the unwanted areas removed by etching or it may be applied (e.g. by a silk screen printing operation) to the wanted areas only. To coat internal (i.e. socket faces) bores, a metallic paste may be carried into the bores on pins and surplus removed by suction. The paste is heated after application as practiced in the art aforesaid.

The method may, in addition, include the steps of inserting a spring contact strip into the sockets, said strip having an extension projecting from the socket and overlying the metallic coating on the external surface of the glass body and securing the extension to the coating.

The contact strips or the contact unit may be produced by etching from sheet metal.

Thus the spring contacts may be constructed by a method which comprises first forming a unit by etching a sheet of metal to provide a blank in the form of a continuous ring which internally is conveniently, but not necessarily, larger than the support plate, and a number selves to make electrical connection with the wires or pins of a plug inserted into the sockets and to urge these wires or pins into electrical contact with the metallic linings of the sockets.

The connector may comprise a stack of such support plates each arranged as described above and each having the same number and arrangement of sockets, there being several through sockets in the stack each of which is provided by corresponding sockets in the several support plates, one of which corresponding sockets is internally coated has a spring and a metal strip extending to the periphery of the support plate, the socket so provided being in diiferent plates for the different through sockets, whereby some pins or wires of an electrical plug connect with one support plate of the stack and some with another support plate of the stack. This arrangement enables the ends of the metal strips to be spaced apart axially of the stack as well as around the periphery of the support plates.

Some specific examples of electrical socket connectors according to the invention and a modifications thereto will now be described with reference to the accompanying diagrammatic drawings in which:

FIGURE 1 is an exploded perspective view of the first connector showing how the connector is constructed,

FIGURE 2 is a plan view of the blank from which the spring contact strips are made,

FIGURE 3 is a perspective view of a second connector with the cover plate removed,

FIGURE 4 is a section through a modified connector,

FIGURE 5 is a perspective view showing another form of socket connector with its associated plug,

FIGURE 6 shows a contact unit from which the resilient contacts of FIGURE 5 are produced,

FIGURE 7 shows, in perspective, a further form of connector,

FIGURE 8 shows the form of plug to be used with the connector of FIGURE 7,

FIGURE 9 is a cross-section, on the line 99, through the connector of FIGURE 7 in position in a panel,

FIGURE '10 is a cross-section on the line 1010 in FIGURE 7, and

FIGURE 11 shows a portion of the contact unit used in the construction of the connector of FIGURE 7.

As can be seen from FIGURE 1 the first embodiment of an electrical socket connector comprises an annular support plate or body providing a ring of sockets 11. The support plate 10 is made from photo-sensitive sheet or plate glass which is sold under the trade name Fotoform. The sockets 11 are made by masking the photosensitive glass with a negative of the desired socket pattern, and exposing the masked glass to ultra-violet light. The portions of the glass which have not been exposed are very much more readily etched than the exposed portions (the solubility ratio of unexposed to exposed portions in hydrofluoric acid is about :1) and when the negative has been removed the selectively exposed glass is immersed in hydrofluoric acid to etch away the exposed glass to form the sockets. The glass is then converted to its ceramic form.

The next stage in the manufacture is to produce metal coatings on selected areas of the support plate 10, these areas being the insides of the sockets and strips 12 extending from the individual sockets to the edge of the plate. The metal (e.g. copper) is applied as a paste and subsequently sintered, as in the decoration of ceramic wares. The paste is carried into the sockets on pins, any surplus being removed by vacuum and is applied either as strips 12 using a silk screen printing technique or over the whole area of the plate, the metal between the strips subsequently being removed by photo-etching.

The next stage is to produce the blank shown in FIG- URE 2 from a sheet of rhodium plated beryllium copper or beryllium nickel. This is done by etching from sheet material using a photo-sensitive resin resist and a master negative. If desired the inner ends of the arms may be connected to a central ring, subsequently removed.

The blank shown in FIGURE 2 comprises an annular ring 14 with arms 15 extending inwardly from the ring 14. Each arm 15 has to be bent to the shape shown in FIGURE 1 with a portion 16 to overlie the metal strip 12- and a spring arm 17 bent downwardly from the portion 16 to lie inside the socket 11.

The step of bending the spring arm 17 downwardly can be accomplished by means of a two part mould, one part of which is placed on one side of the blank of FIGURE 2 and the other part of which is placed on the other side of the blank. When the two parts of the mould are pushed together the arm 15 is bent to the desired shape.

The shaped blank is placed over the support plate with the bent arms 17 entering into the socket. and each arm 15 is welded at 18 and 19 to its corresponding metal strip 12. The outer ring 14 is then cut off to leave each arm 15 as an individual unit held in position on the support plate.

As shown in FIGURE 1 a cover plate 20 may be placed on the finished support plate 10 and the cover plate will have sockets 21 corresponding to the sockets 11 so that the pins or wires of an electrical plug can be pushed through sockets 21 into the sockets 11. The spring arms 17 hold the wires or pins in contact with the metal coatings on the insides of the sockets 11 and in addition themselves make contact with the wires or pins.

The cover plate 20 may be formed by etching in a similar way to the support plate 10 and the cover plate and the support 10 may be held together by means of pins or rivets passing through holes 22 etched in the support plate and the cover plate.

In use of the connector the support plate 10 is placed inside a mating socket forming part of a printed circuit support or the like, and the strips 12 are welded or soldered to corresponding connectionsin purpose there are notches 23 formed in the edges of the arms 15 so that connection can be made to the strips 12 directly.

FIGURE 3 shows a modified form of connector comprising a stack of four support plates 30. Each of the support plates 30 is formed in exactly the same way as the the circuit. For this,

support plate 10 in the first embodiment, with the exception that each support plate 30 has only some of its sockets 11 coated internally, with corresponding metal strips 12 and arms 15. When the pins or wires of a plug are pushed into the connector of FIGURE 3 some of the pins will make connection with the coated sockets in one support plate 30 and others will make contact with coated sockets in another support plate 30. Thus the ends of the metal strips 12 to be connected to an outside circuit are staggered at different levels in the stack for ease of connection.

The connector shown in FIGURE 3 may be provided with a base 31 without socket holes and a cover plate 32 with holes 21.

FIGURE 4 shows a modified way in which the spring arms 15 may be bent. This form may be used in a connector (e.g. that of FIGURE 3) where there are two stacked support plates 30 or more such plates as in FIG- URE 3.

It is not essential that the sockets be arranged in a ring. They may, for example, be in rows as seen in FIGURE 5 in which the sockets are shown at 30' and the pins of a plug contact are shown at 31. The contact strips 32 extend to the edge of the support and are originally produced in the form of a grid as seen in FIGURE 6. Before attachment the arms of the grid are divided at the centre and the two parts bent downwardly and after attachment the bars 33 are removed.

FIGURE 7 shows another form of connector adapted to receive a plug of the form shown in FIGURE 8. The connector body 35 shown in FIGURE 7 is of glass as above described and has a central aperture 37 to receive the body 36 of the plug, the aperture being somewhat longer than the plug. Along each of the longer sides of the connector body there is a row of strips 38, 38a of metal coating on the body. The strips 38a on one side of the body also extend down the side face. At the inner end of each strip the body has a notch 39 and adjacent the inner end there is a recess or hole 40. Welded or soldered to each strip there is a resilient contact 42. These contacts, which are received between the recess 40 and the outside edges of the body, have locating depressions 43 and tags 44 which are secured in the recesses 40 and notches 3-9 (see FIGURE 9). The side edges of the contacts are bent upwardly near the ends as seen at 45 to provide lead-in ramps for the pins 46 of the plug which, as seen in FIGURE 10, are engaged under the ends of the contacts and between these ends and the underlying strips of metal coating. The ends of the row of contacts on one side of the body project in the plane of the upper surface of the body as seen at 48 in FIGURE 9 and after insertion of the body into a hole in a support panel 49 these ends are soldered to a circuit printed on the top surface of the panel. The ends of the other row of contacts are cranked downwardly, as shown at 50, to lie against the under surface of the panel and are secured to a circuit printed on this surface. The contacts may be etched from a sheet in a manner analogous to that shown in FIGURE 6 and the connecting ties cut ofi after attachment. FIGURE 11 shows a portion of the unit after bending of the contacts and before removal of the tie 53.

The photo-sensitive glass and the photo-sensitive resist have been described as being exposed through negatives and positives and it is to be understood that the terms negatives and positives are intended to include metal masks as well as images on the normal photographic plates, films or other supports.

The invention may be applied to miniature switches in which there will be a support of glass or other moulding material with one or more metallic contacts coated thereon, with or without resilient contacts attached thereto, to receive in sliding or pressure contact, the contacts of a companion switch member.

I claim:

1. An electrical socket connector, plug, switch or other electrical contact device comprising a body of insulating material carrying at least one electric contact provided by a metallic coating on the body and a separately constructed resilient contact secured to a metallic coating on the body of insulating material, said first named metallic coating and said resilient contact being arranged to make electrical connection with opposite sides of a cooperating contact inserted between them.

2. A device as claimed in claim 1 in which said second named metallic coating is a part of said at least one metallic contact.

3. A device as claimed in claim 1 in which said second named metallic coating is an extension of said at least one metallic contact.

4. An electrical socket connector as claimed in claim 1 in which said body has at least one socket and in which said resilient contact projects into the socket.

5. An electrical socket connector as claimed in claim 1, in which said body is of glass with at least one socket formed therein, said socket being coated on its internal surface with metal to provide said at least one metallic contact.

References Cited UNITED STATES PATENTS 2,248,718 7/1941 Owen 339 61 2,481,951 8/1949 Sabee 61. al. 156-150 2,692,305 10/1954 Mullin 179 107 2,693,584 11/1954 Pifer 339-47 2,757,349 7/1956 Erbal 339-64 2,869,040 1/1959 Pifer 339- 17 X 2,932,810 4/1960 Novak 339-17 2,953,765 9/1960 Greasley 339-17 2,965,952 12/1960 Gillett et a1. 29- 155.55 2,973,499 2/1961 Hammell ,339-17 3,011,379 12/196-1 Cor-win ,339-17X 3,061,911- 11/1962- Baker.

3,177,103 4/1965 Tally et al. 339-17 X MARVIN A. CHAMPION, Primary Examiner. ALFRED S. TRASK, Examiner.

Claims (1)

1. AN ELECTRICAL SOCKET CONNECTOR, PLUG, SWITCH OR OTHER ELECTRICAL CONTACT DEVICE COMPRISING A BODY OF INSULATING MATERIAL CARRYING AT LEAST ONE ELECTRIC CONTACT PROVIDED BY A METALLIC COATING ON THE BODY AND A SEPARATELY CONSTRUCTED RESILIENT CONTACT SECURED TO A METALLIC COATING ON THE BODY OF INSULATING MATERIAL, SAID FIRST NAMED METALLIC COATING AND SAID RESILIENT CONTACT BEING ARRANGED TO MAKE ELECTRICAL CONNECTION WITH OPPOSITE SIDES OF A COOPERATING CONTACT INSERTED BETWEEN THEM.

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