Potentiometer multifinger contact assembly

Claim 1

In a potentiometer having a resistance element, an electrical return member, a contact-carrier, and means to move the contactcarrier to traverse along an extent of the resistance element; a contact device complementary to the contact-carrier whereby to be traversed by movement of the contact-carrier, said contact device being formed from thin metallic sheet and comprising; a base portion of thin metallic sheet material, having side edges and end portions, and adapted for attachment to the contact-carrier, and a plurality of elongate resilient contact fingers integral with said base portion and each merging with each next adjacent finger and with the base portion in a region of the order of one-sixteenth inch wide and in which each contact finger is in physical contact with each next adjacent other of said contact fingers, and each contact finger diverging away from each next adjacent contact finger so as to be out of physical contact therewith along a major portion of the length thereof so as to be capable of flexing independently of all other of said contact fingers; whereby with an integral one-piece metal contact device in the stated environment, a maximum of effective electrical contact with the resistance element along a line of contact therewith is attained with a concurrent maximum reduction of contact resistance variation as the contact device is traversed along the resistance element.

Claim 5

The method of reducing to a minimum the contact resistance variation in a potentiometer having an electrical return collector means, an elongate resistance element and a metal contact device having a thin sheetlike base portion and contact limbs, said method comprising the steps of: forming by parallel shearing inwardly from one end portion of a sheet of metal, a plurality of elongate resilient contact fingers in contiguous side-by-side disposition while leaving each contact finger in physical contact with each next adjacent finger and each mergent with at least such next adjacent finger and with the base portion in a region of mergence of the order of less than one-sixteenth inch wide; applying forces to at least some of said fingers in the regions of mergence thereof with said base portion, sufficient to permanently deform at least enough of said fingers to cause separation of each of said fingers from any next adjacent finger along a major extent thereof, while leaving each of the contact fingers in contact with each next adjacent finger along a portion thereof close to said base portion, whereby each of the fingers may resiliently flex independently of the others thereof and is positioned to individually make physical and electrical contact with the resistance element, and whereby a maximum number of effective contact fingers is provided between the two most widely separated ones of said fingers.

Claim 6

The method of reducing to a minimum the contact resistance variation in a potentiometer having an electrical return collector means, an elongate resistance element and a metal contact device having a thin sheetlike base portion and contact limbs, said method comprising the steps of: forming by parallel shearing inwardly from one end portion of a sheet of metal, a plurality of elongate resilient contact fingers in contiguous side-by-side disposition while leaving each contact finger in physical contact with each next adjacent finger and each mergent with at least such next adjacent finger and with the base portion in a region of mergence of the order of less than one-sixteenth inch wide; applying forces to at least some of said fingers in the regions of mergence thereof with said base portion, sufficient to permanently deform at least enough of said fingers to cause separation of each of said fingers from any next adjacent finger along a major extent thereof, while leaving each of the contact fingers in contact with each next adjacent finger along a portion thereof close to said base portion, whereby each of the fingers may resiliently flex independently of the others thereof and is positioned to individually make physical and electrical contact with the resistance element, and whereby a maximum number of effective contact fingers is provided between the two most widely separated ones of said fingers.