Actuator mechanism

Claim 2

An electrically-controlled actuating mechanism comprising: a length of shape memory wire, a device movable by said wire to accomplish a desired purpose, means for applying electrical current through said wire, and voltage regulating means connected in parallel with said wire and comprising a pair of diodes connected in parallel with said shape memory wire.

Claim 3

The actuating mechanism of claim 1 further comprising: said pair of diodes comprising a first diode and a second diode connected in series with each other and in parallel with said shape memory wire, said device movable by said wire having a fixed member and a movable member, means electrically connecting said device across said second diode in a manner such that contact of said movable member with said fixed member will create an electrical shunt across said second diode.

Claim 4

The actuating mechanism of claim 2 further comprising: a base, one end of said wire being secured to said base, a rocker member pivotally mounted on said base having a first arm connected to the opposite end of said wire and having a second arm extending at an angle to said first arm connected to said movable member of said device.

Claim 5

The actuating mechanism of claim 3 further comprising: resilient means connected to said second arm of said rocker member to oppose movement of said second arm in a first direction by said wire and to facilitate movement of said second arm in a second direction.

Claim 6

The actuating mechanism of claim 4 wherein: said resilient means is connected between said second arm of said rocker member and a portion of said base.

Claim 7

The actuating mechanism of claim 1 wherein: said device is a model railroad track switch.

Claim 8

The actuating mechanism of claim 1 wherein: said voltage regulating means is operable to apply a first voltage level across said wire to cause constriction of said wire.

Claim 9

The actuating mechanism of claim 7 wherein: said voltage regulating means is resposive to movement of said device to drop the voltage across said wire to a lower level sufficient to maintain said wire in its contracted state without overheating.

Claim 10

An electrically-controlled actuating mechanism comprising: a length of shape memory wire, a device movable by said wire to accomplish a desired purpose, means for applying electrical current through said wire, and voltage regulating means connected in parallel with said wire and operable to apply a first voltage of about 1.4 volts across said wire to cause constriction of said wire.

Claim 11

An electrically-controlled actuating mechanism comprising: a length of shape memory wire, a device movable by said wire to accomplish a desired purpose, means for applying electrical current through said wire, and voltage regulating means connected in parallel with said wire and operable to apply a first voltage of about 1.4 volts across said wire to cause constriction of said wire.

Claim 12

An electrically-controlled actuating mechanism comprising: a length of shape memory wire, a device movable by said wire to accomplish a desired purpose, means for applying electrical current through said wire, and voltage regulating means connected in parallel with said wire and operable to apply a first voltage level of about 1.4 volts across said wire to cause constriction of said wire, said voltage regulating means being resposive to movement of said device to drop the voltage across said wire to a lower level of about 0.7 volts to maintain said wire in its contracted state without overheating.

Claim 13

An electrically-controlled actuating mechanism comprising: a length of shape memory wire, a device movable by said wire to accomplish a desired purpose, means for applying electrical current through said wire, and voltage regulating means connected in parallel with said wire and operable to apply a first voltage level of about 1.4 volts across said wire to cause constriction of said wire, said voltage regulating means being resposive to movement of said device to drop the voltage across said wire to a lower level of about 0.7 volts to maintain said wire in its contracted state without overheating.