US 3737838 A
A printed circuit board connector having a plurality of contacts mounted in the connector housing and the method of assembly thereof. The contacts are formed of a spring contact portion having a contacting surface and terminal portions interconnected by a central mounting portion. The contact is inserted on a mounting member in an unstressed condition with the contacting surface extending from the mounting member in one direction and the terminal portion extending from the mounting member in an opposite direction. A connector housing member contains a slot therethrough for positioning a printed circuit board therein. The connector housing member is positioned on the mounting member. When positioned on the member, curved inner surfaces of the housing member cause the contacts to be spread apart, preloading the contacts at the tip. When the printed circuit board is inserted into the housing, the housing protects the tip member from direct contact by the printed circuit board.
Description (OCR text may contain errors)
United States Patent 91 Mattingly, Jr. et al. 45 June 5, 1973  PRINTED CIRCUIT BOARD Primary Examiner-Marvin A. Champion CONNECTOR Assistant Examiner-Lawrence J. Staab  Inventors: William Russell g, Attorney-C. Cornell Remsen, .lr., Walter J. Baum,
 Assignee: International Telephone and Telegraph Corporation, New York, NY.
 Filed: Nov. 17, 1971  Appl. No.: 199,470
 U.S. Cl ..339/l86 M, 339/17 L, 339/176 MP  Int. Cl ..H05k 1/07, l-lOlr 13/64  Field of Search ..339/17 L, 17 LM, 339/75 MP, 176 MP, 184 M, 186 M  References Cited UNITED STATES PATENTS 3,395,377 7/1968 Straus ..339/l7 L 3,464,054 8/1969 Mansfield ...339/176 MP 3,671,917 6/1972 Ammon et al. ..339/17 L 3,008,113 Johnson ..339/l76 MP Santa Ana; Peter Michael Gregson, Redondo Beach, both of Calif.
A connector housing member contains a Paul l-lemminger et al.
 ABSTRACT A printed circuit board connector having a plurality of contacts mounted in the connector housing and the method of assembly thereof. The contacts are formed of a spring contact portion having a contacting surface and terminal portions interconnected by a central mounting portion. The contact is inserted on a mounting member in an unstressed condition with the contacting surface extending from the mounting member in one direction and the terminal portion extending from the mounting member in an opposite direction. slot therethrough for positioning a printed circuit board therein. The connector housing member is positioned on the mounting member. When positioned on the member, curved inner surfaces of the housing member cause the contacts to be spread apart, preloading the contacts at the tip. When the printed circuit board is inserted into the housing, the housing protects the tip member from direct contact by the printed circuit board.
3 Claims, 4 Drawing Figures Patented June 5, 1973 1 PRINTED CIRCUIT BOARD CONNECTOR BACKGROUND OF THE INVENTION Conventional printed circuit board connectors utilized contacts to electrically connect printed circuit board connectors to a printed circuit board. Typically, the contacts are mounted on a base member or the connector housing, and are preloaded at the base of the contact or at the tip of the contact, near the entry in the connector housing, where the printed circuit board enters the housing. To prevent damage at the tip of the contact, it is necessary to protect the contact tip so that when an external force, such as a printed circuit board, is applied to the connector, the tip does not touch the printed circuit board.
In one form of preloaded printed circuit board contacts, the contacts are press-fitted into the plate through holes of a multilayer board which leaves the contacts in an upright position. The connector insulator is then assembled over the top of the contacts, and the contacts are fully deflected by a molded-in middle card stop web. When the insulator is flush to the multilayer board, the base of the contact presses firmly against the edge of the card stop, preloading the contacts as well as retaining the insulator to the multilayer board. In such an arrangement, full deflection of the contacts is necessary to fully assemble the insulator. Such deflection causes stress to the press-fit portion of the contact in the plated through hole of the board before the insulator is fully assembled. Moreover, each time a printed circuit board is inserted, the same stress occurs. Moreover, in such an arrangement, the tips of the contacts are exposed since the insulator does not have a closed entry arrangement.
In an alternative form of tip loaded printed circuit board connectors,a printed circuit board is inserted between the contacts prior to mounting the connector insulator on the portion multilayer board, having the press-fit contacts thereon. After the contacts have been spread apart between the printed circuit board, the insulator is positioned on the contacts and the tips of the contacts are lodged behind pads molded in the insulator on either side of an insulator slot. Then, the printed circuit board can be removed and the contacts remain preloaded at their tips. The need for a printed circuit board or tool to deflect the contacts before full insulator assembly can be made, results in a cumbersome assembly. Further, it is necessary to deflect the contacts an amount greater than the preloaded condition, thus causing possible overstress to the contacts, should the insulator be mounted on the assembly at an angle.
In order to overcome the attendant disadvantages of prior art printed circuit board connectors, which are preloaded at their tip, the present invention eliminates the need for a board or tool to deflect the contacts prior to insertion of the insulator housing. In the present invention, the connector insulator housing is affixed to the bottom of each contact so as to align the insulator prior to displacement of the contacts, as preloading of the contacts occurs. The insulator housing itself, when fully pressed down and retained by the interference of each contact to each cavity, provides automatic preloading of the contact at the tip. Moreover, the insulator provides closed entry at its engaging end so that the tips of all contacts are protected from damage from the insertion of foreign instruments.
The advantages of the invention, both as to its construction and mode of operation, will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like referenced numerals designate like parts throughout the figures.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts an exploded perspective view, partly in cross-section, of the printed circuit board connector showing the position of the connector members prior to assembly;
FIG. 2 illustrates a cross-sectional view of the printed circuit board connector shown in FIG. 1 with the insulator member partially mounted thereon;
FIG. 3 shows a cross-sectional view of the printed circuit board connector of FIGS. 1 and 2 fully assembled; and
FIG. 4 depicts the printed circuit board of FIGS. 1 through 3 with a printed circuit board inserted therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is shown in FIG. 1 an exploded perspective view partly in section of the electrical connector assembly made in accordance with the principles of the invention. The connector assembly comprises an insulator mounting member 12 having a plurality of bores 14 extendingperpendicularly therethrough. Adapted to be positioned in each of the bores are a plurality of electrical contacts 16. The contacts 16 are formed of a terminal portion 18 and a spring contact portion 22, with the portions 18 and 22 being interconnected by a central mounting portion 24. The contacts 16 are preferably stamped from suitable metal stock to provide the desired strength.
The terminal portion 18 is generally square in crosssection and may be tapered as at its tip end 26 to facilitate insertion of the contact into the bores 14. The spring contact portion is shown as being bifurcated by means ofa slot 28 which opens at the tip end 30 to provide redundant contact points to a conductor which is positioned on a printed circuit board, as well as a multiple frequency of vibrations since each portion is not identical. The spring portion 22 contains a shank end 32 which interconnects the mounting portion 24 to the bifurcated end of the contact. Normally, the spring portiocan be tapered from the shank end 32 to the outer tip end 30 of the spring portion to provide a better distribution of the stress therealong. The spring portion 22 is first bent in a first direction at the shank end 32 and then reverse bent in the opposite direction as at section 34 in the vicinity of the slot 28, with the section 36 defining the junction of the shank end 32 and section 34.
The central mounting portion 24 which interconnects the shank end 32 and the terminal portion 18, is of an approximately equal thickness as these parts at its junctions therewith. However, the mounting portion is slightly wider than the shank end 32 at the junction so as to define an upwardly facing shoulder 38. At its junction, with the terminal portion 18, a tapered transitional section 42 provides the width transition between the terminal portion 18 and the lower end 44 of the mounting portion. The lower end 44 of the mounting portion is not as wide as the upper end 46 of the mounting portion, and a downwardly facing shoulder 48 thereby defines the intersection of the upper and lower ends 44 and 46 of the mounting portion. The width of the lower end 44 is approximately equal to the diameter of the bores 14 so that when the contacts 16 are inserted into the bores 14, the shoulder 48 will rest on the top surface of the mounting member 12, correctly positioning the contacts thereon. As shown in FIG. 2, the contacts 16 are mounted in pairs of rows, and prior to positioning of an insulating member 62 thereon, the section 36 of adjacent contacts touch, or nearly touch each other.
Referring once again to FIG. 1, the insulating housing member 62 comprises a pair of side walls 64 and end walls 66. Normally, the end wall structure 66 is of greater height than the side walls. The side walls 64 terminate at a top wall 68, and a longitudinal slot 72 splits the top wall 68 into symmetrical portions. The slot is defined by inner surface walls 74, which are interconnected to adjacent portions of the top wall 68 by means of a bevelled surface 76. The inner surface walls 74 terminate at a tip 78, and the inner surface 82 of the top wall 68 is connected to the tip 78 by means of an angular surface 84.
Mounted between the inner surfaces of the side walls 64 are mounting members 92 which contain walls 94, extending from the inner surface of the side wall 64 to the inner surface wall 74, and are interconnected by a bottom wall 96. The top surface 98 of the bottom wall provides a stop when the printed circuit board connector is inserted therein. Further, the members 92 may be slotted as at 102, to allow insertion of a polarizing plate 104 therein. the slot 102 normally extends through to the bevelled surface 76 for allowing insertion of the polarizing plate 104 from the top of the insulating member. The bottom wall 96 contains downwardly opening slots 112 which terminate at a shoulder 114.
As shown in FIG. 2 and as previously pointed out, after the contacts 16 have been positioned in the bores 14 of the mounting member, the insulator housing 62 is placed on the contacts. Initially, since a plane along the longitudinal axis of the housing member is parallel to a plane separating the contacts, the housing member is moved in .a downward direction, as shown in FIG. 2, until the upwardly facing shoulder 38 and the upper end 46 of the mounting portion is aligned in the insulator slots 112. [n this portion, the tips of the housing 78 initially touch the section 34 of the contacts. Further, it should be noted that the contact surface of the section 34 abutting the tip 78 forms a slight acute angle with the surface 34.
Since thecontacts in the vicinity of the section 36 are adjacent to each other, further movement of the insulator in a downward direction causes the contacts to be spread apart, as shown in FIG. 3, and the contacts are thus preloaded at the tip. The bottom surface of the insulator member 62 may then be secured to the top surface of the mounting member 12 by conventional techniques.
As shown in FIG. 4, when a printed circuit board 122 having conductors 124 thereon, is inserted into the slots 72 of the insulator member 62, the contacts 16 are electrically connected to the conductors 124. Moreover, it should be noted that the tip end 30 will ride upwardly near the surface 84 of the insulator housing, thus protecting the tips of the contacts from damage when the printed circuit board is inserted.
What is claimed is:
1. A printed circuit board connector comprising:
a mounting member having a pair of rows of openings therein;
a plurality of electrical contacts mounted in said openings in opposed contact pairs;
the contacts of each said contact pairs having mounting portions positioned in said openings, spring portions extending upwardly at an angle from said mounting portions in a direction toward one another, oppositely bent free end sections, and transitional contacting sections joining said spring portions and said end sections;
a housing member positioned over said contacts for preloading said contacts at said free end sections, said housing being formed with a pair of spaced side walls on opposite sides of said rows of contacts, said side walls having lip portions extending downwardly from the upper portions thereof terminating in edges abutting said contact free end sections, said lip portions being spaced apart to define a printed circuit board slot therebetween, said edges holding said contacts in preloaded condition for engagement with a printed circuit board inserted through said slot, said lip portions defining surfaces extending from said edges upwardly and outwardly at an angle with respect to a vertical plane passing througn said slot and at a slight acute angle with respect to the upper surfaces of said contact free end sections.
2. A connector as set forth in claim 1 wherein:
said mounting member is a planar substrate; and
said housing member is a hollow shell with said side walls opening at the bottom thereof to permit said shell to enclose said contacts above said planar substrate.
3. A connector as set forth in claim 2 wherein:
said housing has transverse walls separating adjacent pairs of said contacts;
downwardly opening slots formed in said transverse walls; and
said mounting portions of said contacts including laterally extending portions above said substrate and slidably disposed in said downwardly extending slots.