US PATENT SUBCLASS 338 / 68
MECHANICALLY VARIABLE (E.G., RHEOSTAT)

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

68MECHANICALLY VARIABLE (E.G., RHEOSTAT) {24}
69  DF  .~> Musical instrument playing key actuated
70  DF  .~> In or on lamp socket {4}
75  DF  .~> With resistor cleaner
76  DF  .~> Interchangeable resistors of different resistance value
77  DF  .~> Plug boxes
78  DF  .~> With current reversing (e.g., reversing rheostat)
79  DF  .~> With element winding and/or unwinding
80  DF  .~> Liquid resistance element {4}
87  DF  .~> Contact adjustably inserted into resistance element (e.g., penetrating type) {1}
89  DF  .~> Mathematical function (e.g., sine-cosine potentiometer) {2}
92  DF  .~> Resistance element adjustably short-circuited {5}
98  DF  .~> With motion or vibration damping means (e.g., dashpots)
99  DF  .~> Surfaces pressed together (e.g., compressible type) {2}
114  DF  .~> Deformable
115  DF  .~> Element in piled or stacked layers
116  DF  .~> With electromagnetic operator (e.g., electric motor)
117  DF  .~> Slidable coextensive helical and linear contacts
118  DF  .~> Movable contact electrically adjustable over length of resistance element {21}
195  DF  .~> Resistance value varied by removing or adding material
196  DF  .~> With resistor actuator position indicator
197  DF  .~> With support
198  DF  .~> With switch actuated by resistor actuator
199  DF  .~> With housing
200  DF  .~> With switch {1}

DEFINITION

Classification: 338/68

(under the class definition) Subject matter including a resistance element together with structure for changing a dimension of the resistance element or the effective portion of the resistance element between terminals, as a change in the cross-sectional area or an increase in length of the portion of the resistance element between the terminals; and/or wherein the resistance element is readily adapted or at least adapted for such change in a dimension; or including structure permitting a ready change in the position or point of electrical connection of one or more of the terminals on the resistance element to cause a different portion of the element to be in electrical circuit between the terminals; or including conducting structure which adjustably short-circuits a portion of the resistance element between terminals; or including switching structure which alters the resistance portion of the resistance element in electrical circuit between terminals or which changes the circuit relationship of the resistance element and other resistance elements or which permits the resistance elements to be changed in or removed from the circuit; the result in any of the above being a change in the resistance value between the resistance terminals or the terminals in the circuit including the resistance element; or wherein the resistance element is adapted for or combined with structure for mechanically changing in some manner the resistance element or the combination including the resistance element; or including any other means or adaption of the resistance

element or elements for mechanically changing an arrangement of or effecting a mechanical change in the resistance element or elements to achieve the above mentioned result.

(1) Note. The change in resistance value as stated above is the result of or involves some mechanical change or adjustment on or in the resistance element or terminals, which includes switching of the terminals. The resistance value may be changed otherwise as by change in temperature, electric current therethrough, or voltage applied thereof. This subject matter is classified above, a field of search for such subject matter being given below.

SEE OR SEARCH THIS CLASS, SUBCLASS:

1, for coherer type resistors.

2+, for strain gauge type resistors.

7+, for resistors whose resistance value is temperature compensated. 12, for resistors which are actuated by a magnet through a housing or partition.

13+, for mechanically adjustable resistors which are combined with structure which senses a change in a condition and converts this change into a mechanical adjustment which is applied to the mechanically adjustable resistor to effect a mechanical adjustment therein with a resulting change in resistance value; or for resistors which have the property of changing their resistance value in response to changes in associated conditions to which the resistors are subjected, such as subclasses 15+, for photoconductive resistors; subclasses 20+, for current and/or voltage responsive resistors; subclasses 25+, for resistors responsive to ambient temperature; subclass 32, for resistors responsive to a magnetic field or compass; subclass 33, for resistors with a float actuator; subclasses 34+ for resistors with gas, vapor, or moisture absorbing or collecting; subclasses 36+ for fluid or gas pressure actuated resistors; subclasses 43+ for resistors gravity stabilized or with an inertia actuator; and subclass 47 for force actuated resistors.

60, for resistors with capacitance reducing means.

61+, for resistors with inductance reducing means.

64+, for resistors with electrical shielding.

66, for ignition interference suppressor type resistors.

SEE OR SEARCH CLASS

200, Electricity: Circuit Makers and Breakers, for electrical circuit makers and breakers, per se.

323, Electricity: Power Supply or Regulation Systems,

293+, and subclasses 364+ for regulation systems including a resistor and subclasses 340+ for regulation systems including tap changing.

329, Demodulators, 371, for a coherer type amplitude modulation demodulator.

333, Wave Transmission Lines and Networks,

81, for attenuators, which may be variable.

336, Inductor Devices, appropriate subclasses, for adjustable inductor devices.

361, Electricity: Electrical Systems and Devices,

277+, for variable capacitors.

439, Electrical Connectors, appropriate subclasses, for electrical connectors.

455, Telecommunications,

120+, and 150.1+ for radio transmitter and receiver tuners.