Field of Search:
339/17,19,47-49,154,156,174,176,217,221,252,256,258
Description:
BACKGROUND OF THE INVENTION
1. The Field Of The Invention
The present invention relates to improved connectors for making side or edge contact with conductor pads of circuit boards including electronic modules and in particular to connectors adapted to make side or edge engagement with circuit boards contact pads while providing ready access test access for the contact point.
2. The Prior Art
Electronic circuit modules are produced in many shapes and forms and are fabricated in a variety of sizes, weights and thicknesses. Each module is provided with a circuit or circuits which perform certain desired functions, for example, amplifiers, counters, registers, memory storage, etc. Most of the circuits used are in the miniature and subminiature size range and are therefor difficult to handle. For this reason many of these circuits, which are also called "chips" and/or "flat-packs," are mounted on flat boards with one or more conductive lead extending from the circuit to the edge of the boards for interconnection to a utilization device and/or to a source of electrical energizing potential.
There are known connectors for making connection between an electronic circuit and a source and/or utilization device. For example, U.S. Pat. No. 3,107,319 teaches a modular component to printed circuit connector with a cantilever leg providing a resilient contact with a printed circuit board. Another leg is used for solder contact with circuit components and is not suitable for making edge or surface contact with a circuit module. U.S. Pat. No. 3,622,950 shows a connector assembly having integral terminal posts. Conductors from a circuit module are tightly received between biased arms to make connection with the terminal contact. This connector requires an additional member to achieve the biasing.
SUMMARY OF THE INVENTION
The present invention is an electrical connector for electrically and mechanically interconnecting spaced terminal pins with more closely spaced edge or surface contact pads on a circuit board carrying an electronic module. The connector includes a body, a resilient contacting arm lying in the plane of the body and adopted to engage contact pads of the circuit board, a terminal pin extending from the body for further electrical interconnection, and test access means extending from the body to project from a housing to provide a constant test point. The housing includes a circuit board and electronic module receiving portion and a plurality of connector receiving grooves formed along at least part of the periphery of the housing.
It is therefore an object of the present invention to construct a new and improved electrical connector which will provide sufficiently high contact forces to form a gas tight seal at the electrical junction between a contact arm of the connector and the associated circuitry module contact pad.
It is another object of the present invention to produce electrical connectors capable of making either edge or surface engagement with contact pads of a circuit module.
It is yet another object of the present invention to construct electrical connectors which can mate with terminal posts or have integral terminal posts.
It is still another object of the present invention to produce an electrical connector which, when mounted in an associated housing, will have a portion thereof projecting from the housing and serving for test access to the contact.
The foregoing and other objects of the present invention will become apparent to those skilled in the art from the following detailed description taken with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly in section, of a housing having the first embodiment of the subject connector mounted therein;
FIG. 2 is a partial transverse vertical section through the housing of FIG. 1;
FIG. 3 is a side elevation of the first embodiment of the subject connector;
FIG. 4 is a schematic top plan view showing the orientation of the first embodiment connector in the housing;
FIG. 4a is a bottom plan view of a fragment of the housing showing two loaded and one empty cavities;
FIG. 5 is a perspective view, partially in section, of a housing having a second embodiment of the subject connector mounted therein;
FIG. 6 is a partial transverse vertical section through the housing of FIG. 5;
FIG. 7 is a side elevation of the second embodiment of the subject connector;
FIG. 8 is a schematic top plan view showing the alignment of the second embodiment connector in the housing;
FIG. 9 is a perspective view, partly in section, of a housing having a third embodiment of the subject connector mounted therein;
FIG. 10 is a partial transverse vertical section view through the housing of FIG. 9;
FIG. 11 is a side elevation of the third embodiment of the subject connector;
FIG. 12 is a schematic top plan view showing the mounting of the third embodiment connector in the housing;
FIG. 13 is a perspective view, partially in section, of a housing having a fourth embodiment of the subject connector mounted therein;
FIG. 14 is a partial transverse vertical section through the housing of FIG. 13; and
FIG. 15 is a schematic top plan view showing the orientation of the fourth embodiment connector devices in the housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The several embodiments of the present connector are described making interconnection with packaged electronic modules, such as may be found in computers and the like. In such cases the electronic modules 10 are mounted on a rigid circuitry boards 12 having electrical leads 14 printed thereon extending radially outwardly to an edge portion of the board where a contact pad is formed on either the edge or surface of the board. Since the modules are of extremely small size, the leads must be made to radiate therefrom in order to provide sufficient spacing at the sides of the board for making contact with the related circuitry, such as either a source of potential or a utilization device. The present connectors serve to make good electrical and mechanical interconnection between pads having a first grid spacing and terminal pins having a second larger grid spacing.
Turning now to the first embodiment of the subject connector, see FIGS. 1 to 4, a housing 16 has a stepped central recess 18 extending substantially its entire longitudinal length. A plurality of spaced, parallel connector cavities 20 are formed along at least one wall of the housing. Each cavity 20 includes a notch or recess 22, see FIG. 4a, and communicates with recess 18 via longitudinal slot 24. The housing 16 is mounted on a chassis or support frame 26 in close proximity to a plurality of apertures 28 and is fixed in position by conventional mounting means 30, such as nuts and bolts or screws. The circuit board 12 is fixedly mounted in the housing 16 by conventional mounting means 32 and a single mounting means can be used to mount both the board on the housing and the housing on the chassis if so desired.
The first embodiment of the subject connector 34 is formed from premilled flat stock and has a transverse step 36 (see FIG. 4) extending through body portion 38. An integral terminal pin 40 of square section depends from the thicker bottom side of the body portion 38. The terminal pin 40 is rotated about its own axis to be angularly positioned with respect to the plane of the connector. Resilient arms 42, 44 extend in cantilever fashion from opposite sides of body portion 38 and a folded cantilever arm 46 extends from the top of the body portion. A contact projection 48 is on the free end of the arm 46. Retention projections 50 extend from opposite sides of the thicker lower part of the body portion 38.
The first embodiment connector 34 is mounted in the cavities 20 from the bottom of the housing 16 in an alternating reversed configuration (see FIG. 4) so that the contacts 48 are spaced close enough to engage pads 14 on the circuit board 12 while the terminal pins 40 are spaced somewhat further apart enabling other connections to be made therewith. It should be noted that the apertures 28 are formed in two spaced, parallel rows and that the terminal pins 40 are inserted in alternate apertures to achieve the desired spacing.
The connectors 34 are inserted from the bottom of the housing 10 into slots 20 with one resilient arm, in this case 42, engaging the rear wall 52 of the slot to bias the connector so that the opposite retention projection 50 engages in the notch 22 to firmly hold the connector in position. The other resilient arm 44 extends from the side of the housing and serves as the test point. The end contact 48 engages the surface pad 14 of the circuit board 12 while terminal pin 40 depends through an aperture 28 of chassis 26 for appropriate engagement with plugs, wire wrapping, soldered and other available connections.
It should be here noted that all four embodiments of the subject connector are stamped from flat stock and used in edge wise orientation which gives maximum stiffness for a given material thickness. Only the first embodiment, as noted above, is stamped from premilled stock in order to have sufficient thickness to form the terminal pin.
The second embodiment of the subject connector 54, see FIGS. 5 to 8, is symmetrical and therefor is mounted in the housing 10 aligned in a single direction. The connector 54 includes a body portion 56, a plurality of legs 58, 60, 62 and 64 depending from the bottom of the body portion, retention projections 66 extending from opposite sides of the body 56, and contact arm 68 extending upwardly from the body and carrying a contact portion 70 thereon. A flat spring arm 72 extends from leg 64 to project out of the housing 16 and serve as a test point. Retention of the connector in the housing is accomplished by projections 66 on each side of the connector body 56 engaging the opposing walls 76, 78 of the housing 16.
Separate terminal posts 74 are fixedly mounted in alternate apertures 28 of the chassis 26. The face portions of the legs 58, 60, 62, 64 contacting the terminal posts 74 have coined edges to assure flat to flat mating between terminal posts and connector legs even though the connector 54 is obliquely positioned in the housing as shown in FIG. 8. The legs which engage the terminal post behave as cantilever springs while the contact arm 68 engaging the electronic module pad 14 functions as a simple beam with fixed ends. In this manner forces consistent with the use of non-noble plating may be obtained in compact form.
The connector slots 20 in the molded plastic housing assure proper orientation of all of the interengaging elements. Since the slots are positioned on an angle with respect to the major axis of the housing, the legs of the contacts are positioned so that one pair will engage the associated terminal pin.
The third embodiment 80 of the present invention is similar to the second embodiment in that it is intended for use with terminal pins 74 fixed in the chassis 26. This embodiment includes a contact body 82 having at least two pairs of depending legs 84, 86, 88, 90 and an oppositely directed stud 92 having laterally extending retention projections 94. A folded cantilever beam 96 depends from one end of the connector body 82 in the manner of arm 46 of the first embodiment. This beam extends upwardly and inwardly with respect to the housing so that a contact projection 98 on the free end thereof engages a pad 14 on the side edge of the circuit board 12. The cantilever beam 96 also has an edge portion 100 which projects through the side wall of the housing to provide a test access point.
The faces of the legs 84, 86, 88 and 90 which contact the terminal posts 74 have coined edges to assure flat mating between post and connector even though the connector is obliquely positioned in its housing, as shown in FIG. 12. The members which engage the terminal post behave as conventional cantilever springs while the beam engaging the edge pad functions as a heavy recurved cantilever fixed to the main body of the connector. In this manner forces consistent with the use of non-noble platings may be obtained in compact form. The connector is mounted in the housing by inserting stud 92 into a corresponding recess 102 in the housing 16. The molded plastic housing assures proper orientation of all of the interconnecting elements even with the contact cavities positioned on an angle with respect to the major axis of the housing.
The fourth embodiment 104 of the subject connector is designed for making surface to surface connection between the circuit board 12 and a printed circuit 106 on chassis 26. This connector is formed from flat stock and has a body portion 108 with a pair of cantilever arms 110, 112 extending therefrom. Each arm has a folded configuration with a contact portion 114, 116, respectively engaging the associated circuitry. The arm 112 has an extension 118 which will project from a side of the housing to provide test access. This surface to surface connector uses a flat blank contact to resiliently connect between two opposite parallel pads of an electronic element and printed circuit substrate. Thus the modified cantilever springs of this contact can furnish forces which would be consistent with non-noble surface coatings used in electrical applications.
The present invention is subject to many modifications and variations without departing from the spirit or essential characteristics thereof. The above described embodiments are therefore to be considered in all respects as being illustrative and not restrictive of the scope of the invention.