US 3422394 A
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Description (OCR text may contain errors)
Jan- 14, 1969 v .1. E. ANTES 3,422,394
ELECTRICAL CONNECTOR Filed Aug '24, 1965 Fig. 2..
Jack 'E. Antes,
United States Patent Claims ABSTRACT OF THE DISCLOSURE This is an electrical connector for circuit boards which comprises a plurality of contact members each retained in a; cavity in a connector plug. The contact members and cavities are of such a shape to enable the contact member to be locked in the cavity against axial movement but with a looped contact portion free to move in a sliding contact with the circuit board.
This invention relates to an electrical connector and more particularly to a class of electricalconnectors called microminiature connectors for connecting external electric circuits to integrated circuits and discreet microcomponents associated with printed circuit boards.
With the development of integrated circuits and microminiature electrical components and the arranging of such components on circuit boards, a need has arisen for efiicient and reliable methods for the connection of such components and boards to external electrical circuits. Because of the small size of these components and circuit boards and their frequent use in high reliability devices and systems, the connector developed for this purpose must also be small, durable, and provide high conductivity even after extended periods of use and repeated engagement and separation.
In the design of an effective circuit board connector to achieve maximum utilization of a minimum area, it has been found desirable to retain a plurality of such contact elements in a single receptacle block and to springload each contact element. By spring-loading each contact element, a more effective electrical conductivity and structural rigidity of the elements is achieved. Heretofore, the common practice has been to provide this loading by external or auxiliary springs. However, these have been found to be too complex and costly for high production use and introduce size limitations.
Therefore, it is an object of the present invention to provide an improved and more efiicient electrical connector for a mating connector or printed circuit board.
Another object of the present invention is to provide an improved electrical connector having a spring loaded contact element constructed to effectively engage a mating element without fatigue or distortion of the element.
A further object of the present invention is to provide an improved electrical connector for printed circuit boards having mutually engaging portions which remain in sliding contact during deflection of a contact element as a circuit board is brought into engagement with the contact element.
Briefly, the improved electrical connector of the present invention comprises a connector block or insulating memher having one or more transverse chambers or cavities and a longitudinal recess for receiving a mating connector element such as a printed circuit board. A resilient contact member including a loop contact portion having leg portions with mutually engaging intermediate parts is spring loaded into each of said chambers. Although the contact members are looked in position against axial movement, the engaging parts are free to move in sliding contact as Patented Jan. 14, 1969 "ice the engagement of the contact member with the mating connector element displaces the loop portion.
Other advantages of the invention will hereinafter become more fully apparent from the following description of the drawings which illustrate a preferred embodiment thereof and in which:
FIGURE 1 is a perspective view of a portion of a connector block shown in section to show the positioning of the contact member;
FIG. 2 is an enlarged sectional view of a portion of the connector block and a printed circuit board showing a contact member in contact with a printed circuit board and illustrating in dashed lines the position of the contact loop prior to the insertion of the printed circuit board; and
FIG. 3 is a perspective view of a typical printed circuit board engagingthe connector body of the present invention showing the electrical conductor terminations and having a portion cut away to show a typical electrical element mounted on the circuit board.
Referring now to FIGS. 1 and 2, a connector block or insulating member 10 of a plastic material such as diallyl phthalate has been formed such as by molding to include a plurality of transverse chambers or cavities 12 and a longitudinal recess 14. Typically, the body includes a flange 16 at each end having a bore or aperture 18 for mounting the body 10 to a support structure by bolts or screws (not shown). A contact member or element 20 typically formed from a metal fiat strip or wire such as high conductivity copper alloy, nickel alloy or beryllium copper alloy and having a unique shape is looked into contact position in each of the chambers 12.
While in FIG. 1 there is shown and hereinafter described a connector block with opposing chambers and contact elements, it should be understood that without varying from the scope of the present invention one of the rows of connector elements may be eliminated if it is desired to make contact with only one side of a printed circuit board.
Each of the contact members 20 has been folded or upset from a continuous flat strip or wire having a generally uniform cross section into a configuration including a convex or open contact loop portion 22 having first and second leg portions 24 and 26. The first leg 24 includes a first knee 28, a protrusion or convexity 30 which as described later assists in locking the contact member 20 in the chamber 12, and a terminal portion 31. The second leg includes a second knee 32 of greater curvature than the first knee 28 and a looped end portion 34.
Each of the chambers 12 extends through the connector block 10 from top to bottom as shown in the figures and with the exception of a locking or shoulder portion 36 is of substantially uniform width. A divider or barrier 38 extends into the chamber 12 at the bottom as oriented in the figures and divides a portion thereof into two chambers having a restricted portion 39. The divider 38 has a first and a second inclined surface 40, 42 which function to support the second knee 32 and for locking the end loop portion 34 of the second leg 26 respectively.
The positioning and locking of each of the contact members in a chamber is accomplished by inserting the contact loop portion 22 into the top of the chamber and into the restricted portion 39 with the end loop portion .34 engaging the first leg 24 and the first knee 28 in contact with a portion 29 of the second leg 26. As the contact member 20 is inserted further toward the bottom of the block 10, the portion 29 slides across the first knee 28 and places the member in torsion and permits the first leg 24 to deflect toward the wall of chamber 12. Further inserting causes the first k-nee 24 to seat on the shoulder 36 by the locking of protrusion 30 against the shoulder 36 and the end of the loop portion 34 looking against the second inclined surface 42 with a part of the second knee 32 retained between the first knee 28 and the first inclined surface 40. The contact of the second knee 32 with the inclined surface 40 supports the contact element from undesired tipping or clockwise deflection.
As shown by the dashed lines in FIG. 2, after the completed assembly of the contact members in the connector block, the contact loop 22 of each member is in a first position, which changes to a second position (solid lines) when a mating element or printed circuit board 44 is inserted into the block 14 and into contact with the loop portion 22. As the loop portion 22 deflects, the second leg 26 cants toward the left side of chamber 12, as viewed in FIGS. 1 and 2, and a torsional twist is introduced into the contact member 20 by the leg portion 29 sliding along the first knee 28 but no movement is transmitted to the contact element at the locking points provided by the protrusion 30 and the end of the loop portion 34.
When a source of electrical power is coupled to the terminal lead 31, the path of electrical current to the circuit board conductor is from the lead 31 to the point of contact between the first and second legs 24, 26 where it splits into dual paths following both legs to the point of contact of the contact loop portion 22 with the circuit board conductor. To prevent shorting or arcing between adjacent contact elements, each of the elements is separated by a wall or barrier 50, which is preferably formed as an integral part of the insulating material of the block 10.
In FIG. 3 is shown a typical application of an embodiment of the improved electrical connector of the present invention wherein a printed circuit board 44 having a plurality of terminal conductors 52 coupled to various electrical components, such as shown at 56, is inserted into the body with each of the terminal conductors 52 in electrical contact with a contact loop (not shown) associated with the terminals 31 projecting from the bottom of the block.
While one embodiment of this invention has been herein illustrated and a slight modification of this embodiment has been described, it should be appreciated by those skilled in the art that variations of the disclosed arrangement both as to its details and the operation of such details may be made without departing from the skill and scope thereof. Accordingly, it is intended that the foregoing disclosure and the showings made in the drawings may be considered as illustrative of this invention and not construed in a limited sense.
What is claimed is:
1. An electrical connector comprising:
an electrical insulating member having one or more cavities each including a shoulder and a divider and adapted to receive a mating electrical contact element; and
at least one resilient contact member positioned in each of said cavities, said contact member having a contact portion at one end including an open loop having leg portions with a pair of mutually engaging parts forming a collapsible parallogram upon entry into said one cavity and defining parallel electrical paths, said parts being free to move as the contact portion is displaced into spring loaded contact as the mating contact element engages said insulating member and at the other end a locking means for locking said member in contact with said shoulder and divider.
2. An electrical connector comprising:
an electrical insulating member having one or more cavities each including a shoulder and a divider and adapted to receive a mating electrical contact element;
at least one resilient contact member positioned in each of said cavities, said contact member having a contact portion at one end including an open loop having leg portions with mutually engaging parts, said parts being 'free to move as the contact portion is displaced into spring loaded contact as the mating contact element engages said insulating member and at the other end a locking means for locking said member in contact with said shoulder and divider and wherein said means for locking the resilient contact member in contact with the shoulder and the divider comprises a knee and a protrusion formed in one leg portion located to engage said shoulder on opposite sides thereof and an end loop in the other leg portion shaped to engage said divider.
3. The electrical connector of claim 2 wherein the resilient contact member is a fiat metallic strip and the mating connector is a printed circuit board.
4. The electrical connector of claim 3 wherein engagement of said printed circuit board with said loop element causes one of said mutually engaging parts of said contact member to slide over the other part with substantially no movement of said contact member at said knee and at the point of engagement of said end loop with said divider.
References Cited UNITED STATES PATENTS 3,015,083 12/1961 Juris 3392l7 X 2,882,511 4/1959 Mason 339176 3,172,717 3/1965 Clewes 339-176 3,209,310 9/1965' Schwartz et al 3392l7 MARVIN A. CHAMPION, Primary Examiner.
J. R. MOSS, Assistant Examiner.
US. Cl. X.R.