Rotor and shaft assembly for variable resistor

Claim 2

A rotor and shaft assembly for a variable resistance device or the like comprising: a rotor adapted to be rotated about its axis and to support an electrically conductive contact member for rotation about an arcuate path, said rotor including a shaft supporting shank having a slot therein, said slot including an upper portion and a lower undercut portion, said undercut portion being of a width greater than said upper portion so that there is an overhanging upper surface above at least a part of said lower portion of said slot, said lower portion of said slot having a hole formed in the lower surface thereof; a shaft including a driving head on one end thereof, said shaft being of a width adapted to fit within said upper portion of said slot and said driving head being substantially in the shape of a parallelepiped with parallel upper and lower surfaces arranged substantially normal to the axis of said shaft and extending beyond the circumference of said shaft and side surfaces connecting at an angle with said top and bottom surfaces, said driving head being positioned within said undercut portion of said slot, said driving head including an embossment protruding from the bottom surface thereof and extending into said hole formed in the bottom surface of said slot thereby preventing lateral movement of said shaft and said driving head when said shaft is positioned along the axis of rotation of said rotor.

Claim 3

The rotor and shaft assembly defined in claim 1 in which said embossment protruding from the bottom surface of said driving head is cone-shaped and said hole in the lower surface of said slot is similarly shaped.

Claim 4

The rotor and shaft assembly defined in claim 2 in which said cone-shaped embossment protruding from said lower surface is an extension of one of the connecting surfaces between said parallel upper and lower surfaces of said driving head.

Claim 5

The rotor and shaft assembly defined in claim 1 in which said driving head is in the shape of a parallelepiped having equilateral sides.

Claim 6

The rotor and shaft assembly defined in claim 3 in which the upper and lower surfaces of the driving head are parallel and the connecting surfaces to these surfaces are parallel and spaced apart a distance slightly less than the distance between said lower surface of the rotor slot and said overhanging upper surface of said slot.

Claim 7

A variable resistance device comprising: a housing substantially open at oNe end and defining a cavity; a base member supported across said open end of said housing, said base member having an annular resistance element and a collector element mounted thereon; a rotor mounted within said cavity, said rotor including a shaft supporting shank having a slot therein, said slot including an upper portion and a lower undercut portion, said undercut portion being of a width greater than said upper portion so that there is an overhanging upper surface above at least a part of said lower portion of said slot, said lower portion of said slot having a hole formed in the lower surface thereof; a drive shaft having one end extending through an end of said housing and including a driving head on the other end thereof, said shaft being of a width adapted to fit within said upper portion of said slot and said driving head being substantially in the shape of a parallelepiped with parallel top and bottom surfaces arranged substantially normal to the axis of said shaft and extending beyond the circumference of said shaft and side surfaces connecting at an angle with said top and bottom surfaces, said driving head being positioned within said undercut portion of said slot, said driving head including an embossment protruding from the bottom surface thereof and extending into said hole formed in the bottom of said slot thereby preventing lateral movement of said shaft and said driving head when said shaft is positioned along the axis of rotation of said rotor; and an electrically conductive contact member attached to said rotor for rotation therewith, said contact member having a plurality of resilient wiper arms engaging said resistance and said collector elements on said base member for traversing these elements on rotation of said rotor.

Claim 8

A variable resistance device comprising: a housing substantially open at oNe end and defining a cavity; a base member supported across said open end of said housing, said base member having an annular resistance element and a collector element mounted thereon; a rotor mounted within said cavity, said rotor including a shaft supporting shank having a slot therein, said slot including an upper portion and a lower undercut portion, said undercut portion being of a width greater than said upper portion so that there is an overhanging upper surface above at least a part of said lower portion of said slot, said lower portion of said slot having a hole formed in the lower surface thereof; a drive shaft having one end extending through an end of said housing and including a driving head on the other end thereof, said shaft being of a width adapted to fit within said upper portion of said slot and said driving head being substantially in the shape of a parallelepiped with parallel top and bottom surfaces arranged substantially normal to the axis of said shaft and extending beyond the circumference of said shaft and side surfaces connecting at an angle with said top and bottom surfaces, said driving head being positioned within said undercut portion of said slot, said driving head including an embossment protruding from the bottom surface thereof and extending into said hole formed in the bottom of said slot thereby preventing lateral movement of said shaft and said driving head when said shaft is positioned along the axis of rotation of said rotor; and an electrically conductive contact member attached to said rotor for rotation therewith, said contact member having a plurality of resilient wiper arms engaging said resistance and said collector elements on said base member for traversing these elements on rotation of said rotor.

Claim 9

The variable resistance device of claim 6 in which said driving head is in the shape of a parallelepiped having equal lateral sides.

Claim 10

The variable resistance device defined in claim 6 in which said embossment protruding from said bottom surface of said driving head is cone-shaped and said hole in the lower surface of said slot is similarly shaped.