US PATENT SUBCLASS 338 / 138
.~.~ Element tapered

Current as of: June, 1999
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338 /   HD   ELECTRICAL RESISTORS

68  DF  MECHANICALLY VARIABLE (E.G., RHEOSTAT) {24}
118  DF  .~ Movable contact electrically adjustable over length of resistance element {21}
138.~.~ Element tapered {4}
139  DF  .~.~.~> Portion of element shorted
140  DF  .~.~.~> With intervening connector between contact and element (e.g., taps)
141  DF  .~.~.~> Helical or wound
142  DF  .~.~.~> Element forms a coating

DEFINITION

Classification: 338/138

(under subclass 118) Subject matter wherein a physical dimension or characteristic of the resistance element changes in one direction gradually or in a plurality of discrete progressive steps along the element as recited in subclass 217 below.

(1) Note. Usually the purpose of this tapered characteristic in a variable resistor is to provide a nonlinear relationship between the change in value of the resistance and movement of the contact arm. Subclasses 89+ above provides for such structure where a definite mathematical relationship exists.

SEE OR SEARCH THIS CLASS, SUBCLASS:

89+, for variable resistors wherein a definite mathematical relationship exists between the value of the resistance across the terminals and movement of the resistor actuator. See also (1) Note above.

217+, for tapered resistors generally.