Non-shortning pin system

Abstract

The invention is a zero insertion force printed circuit board edge connector that ensures electrical connection under a worst-case accumulation of mechanical tolerances while precluding the short circuiting of connector contact pins in the absence of a board within the connector. The contact pins of the connector are formed so that the contact regions of the contact pins lie in at least two horizontal planes. The longer pins located on one side of the connector are located opposite the shorter pins on the other side of the connector. When the connector is actuated in the absence of a printed circuit board, the short pins will move under the opposing long pins but the pins will not short circuit. During actuation, the pins will move more than half way across the connector opening thereby guaranteeing connection to any card regardless of dimensional tolerance or of card position within the connector opening.

I claim: 
     
       1. In a zero insertion force type electrical connector for receiving an electrical component type having a plurality of rows of contact pads disposed on opposite sides of a flat surface thereof, said contact pads including a first row of pads on a given side of said electrical component offset and interleaved with respect to pads in an adjacent second row and on the same side of said electrical component, insulating gaps separating said pads in said first row narrower than the width of the contacting region of said pads in said second row to provide a high density contact pad pattern, an electrical connector comprising: a housing of electrically insulating material having a base and two side walls together defining an elongated opening at the top of said housing for receiving therein said electrical component;   upper inclined surfaces on the inside of each side wall of said housing facing the elongated opening in said housing;   lower inclined surfaces on the inside of each side wall of said housing facing the elongated opening in said housing;   a first row of spring-like contact pins having alternating long and short pins on one side of said elongated opening;   a second row of spring-like contact pins having alternating long and short pins on the other side of said elongated opening in staggered relation to said first row of contact pins wherein the long pins of said first row are opposite said short pins of said second row and the short pins of said first row are opposite said long pins of said second row;   contact regions of said short contact pins for contacting the interleaved contact pads located in the row of pads nearest to the edge of the electrical component;   contact regions of said long contact pins for contacting the interleaved contact pads located in the row of pads farthest from the edge of the electrical component;   actuating means for moving said .Iadd.side walls of said .Iaddend.housing .Iadd.away from said base .Iaddend.in a vertical plane wherein said lower inclined surfaces urge said short contact pins and said upper inclined surfaces urge said long contact pins in a direction toward the center of said elongated opening;   said contact regions of said short pins passing through said centerline of said elongated opening wherein the contact region of each short pin is below said contact region of said opposite long pin thereby precluding opposite facing contact pins from contacting and short circuiting when the contact pins are actuated in the absence of an electrical component within the connector; and   said contact regions of said long pins passing through said centerline of said elongated opening wherein the contact region of each long pin is above said contact region of said opposite short pin thereby precluding opposite facing contact pins from contacting and short circuiting when the contact pins are actuated in the absence of an electrical component within the connector.[.;.]. .Iadd.. .Iaddend.   .[.upon insertion of an electrical component vertically into said elongated opening of said housing through a vertical plane oriented substantially parallel with the longitudinal dimension of said elongated opening, electrical connection is completed..]. .Iadd.   
     
     
       2.  A zero insertion force type electrical connector for receiving an electrical component having a plurality of rows of contact pads disposed on opposite sides of a flat surface thereof comprising: a housing of electrically insulating material having a base and two side walls together defining an elongated opening at one end of said housing for receiving therein said electrical component;   first inclined surfaces on the inside of each side wall of said housing facing the elongated opening in said housing;   second inclined surfaces on the inside of each side wall of said housing facing the elongated opening in said housing and further removed from said opening than said first inclined surfaces;   a first row of spring-like contact pins having alternating long and short pins on one side of said elongated opening;   a second row of spring-like contact pins having alternating long and short pins on the other side of said elongated opening in staggered relation to said first row of contact pins wherein the long pins of said first row are opposite said short pins of said second row and the short pins of said first row are opposite said long pins of said second row;   actuating means for moving said side walls of said housing away from said base wherein said second inclined surfaces urge said short contact pins and said first inclined surfaces urge said long contact pins in a direction toward the center of said elongated opening;   said contact regions of said short pins passing through said centerline of said elongated opening wherein the contact region of each short pin is under said contact region of said opposite long pin thereby precluding opposite facing contact pins from contacting and short circuiting when the contact pins are actuated in the absence of an electrical component within the connector; and   said contact regions of said long pins passing through said centerline of said elongated opening wherein the contact region of each long pin is over said contact region of said opposite short pin thereby precluding opposite facing contact pins from contacting and short circuiting when the contact pins are actuated in the absence of an electrical component within the connector. .Iaddend. .Iadd.   
     
     
       3.  A zero insertion force, card edge connector, adapted to engage the conductive traces on a card inserted in a card receiving slot in the connector, comprising: a. an elongated first housing with a base;   b. an elongated second housing positioned over the first housing having a longitudinally extending card receiving slot and cam surfaces facing the slot with said cam surfaces being located at more than one level position;   c. cam means positioned between the first and second housings for moving the second housing away from said first housing; and   d. contact elements arranged in a pair of rows and retained in the base in the first housing, each element having a cantilevered portion extending into the second housing between the slot and cam surfaces with a contact surface facing the slot for engagement with a conductive trace on a card inserted in the slot, and a convex surface positioned adjacent a cam surface on the second housing for engagement with the cam surface during movement of the second housing away from said first housing to move the contact surface into engagement with a trace on a card positioned in the slot, the cantilevered portions of the elements on each side of the slot being longitudinally spaced from each other,   the elements being arranged in opposing pairs whose contact surfaces face one another across the slot, the contact surfaces on adjacent elements along each side of the slot being located at different positions, and the facing contact surfaces on elements located on opposite sides of the slot located at different level positions and further with all elements having contact surfaces at each level position having their associated cam surfaces located at one level position. .Iaddend.