Potentiometer comprising a transport screw

Claim 2

A potentiometer comprising, a. a casing having a trough-shaped inner space defined by walls and a resistance track, b. a transport screw spindle rotatably mounted in the casing, c. a linearly displaceable contact member comprising an electrically nonconductive slide having (i) a groove part disposed against the spindle and (ii) at least one side portion engaging one casing wall to prevent rotation of the slide, and d. a contact spring having a first portion engaging the spindle screw thread and operable as a nut, a second portion engaging the slide to move same axially with respect to the spindle, and a third part resiliently engaging the resistance track.

Claim 3

A device according to claim 1 wherein the spring urges the slide against the spindle.

Claim 4

A device according to claim 1 wherein the spring is a wire formed in a U-shape whose end portion engages the slide and said screw thread, and whose limbs contact the resistance track.

Claim 5

A device according to claim 3 wherein the slide includes two longitudinal slots which are engaged by limbs of said spring.

Claim 6

A potentiometer comprising a contact member adapted to be displaced linearly by means of a transport screw spindle in a trough-shaped casing, and comprising a contact spring having a portion engaging the screw thread of the spindle and operating as a nut and as a contact and whose second portion forms a sliding contact adapted to move along a resistance track, characterized in that the contact member is located between the spindle and the bottom of the trough and comprises an elongated sledge extending parallel to the transport spindle having a gutter-shaped profile slidingly fitting to the spindle, said sledge being laterally guided by the inner walls of the trough so as to prevent rotation and being urged by the contact spring against the spindle, said contact spring having the form of a metal wire bent to the shape of a U whose closed end portion is slightly bent over and is taken through a fitting transverse slot near one end of the sledge, the web portion of said end portion engaging the screwhead of the spindle, whereas the limbs of the U-shaped spring have a further bent portion or knee projecting from the sledge and contacting under inherent spring pressure a resistance track on the bottom of the trough whereas the ends of the limbs of the contact spring engage the surface of the sledge facing the resistance track.

Claim 7

A potentiometer comprising a contact member adapted to be displaced linearly by means of a transport screw spindle in a trough-shaped casing, and comprising a contact spring having a portion engaging the screw thread of the spindle and operating as a nut and as a contact and whose second portion forms a sliding contact adapted to move along a resistance track, characterized in that the contact member is located between the spindle and the bottom of the trough and comprises an elongated sledge extending parallel to the transport spindle having a gutter-shaped profile slidingly fitting to the spindle, said sledge being laterally guided by the inner walls of the trough so as to prevent rotation and being urged by the contact spring against the spindle, said contact spring having the form of a metal wire bent to the shape of a U whose closed end portion is slightly bent over and is taken through a fitting transverse slot near one end of the sledge, the web portion of said end portion engaging the screwhead of the spindle, whereas the limbs of the U-shaped spring have a further bent portion or knee projecting from the sledge and contacting under inherent spring pressure a resistance track on the bottom of the trough whereas the ends of the limbs of the contact spring engage the surface of the sledge facing the resistance track.

Claim 8

A potentiometer as claimed in claim 5, characterized in that the limbs of the U-shaped contact spring are located for the major part in two fitting longitudinal slots in the side of the sledge facing the resistance track from which slots said further bent portions of the contact spring protrude.