Eaton Corporation

John W Kroll

Jerome Kenneth Hastings

John R Brubaker

Michael S Baran

Robert B Bridges

James E Mading

Roy Hyink

In a bistable shape memory effect, SME, mechanism having first and second opposing shape memory effect, SME, elements (16, 20) moving an actuator (12) along a travel stroke between respective first and second positions upon heating of the respective SME element above its transition temperature mechanical frictional retainers are provided for holding the actuator at the end of its travel stroke, including after cooling of the respective SME element and return repose movement thereof. One embodiment provides a detent retainer (38, 40, 42, 44, 46). Another embodiment provides a friction wedge retainer (12a, 12b, 14a, 14b, 12c, 12d, 14c, 14d). Another embodiment provides a resiliently biased friction member (50, 52) and a lost motion coupling (56, 58) between the actuator and the SME elements.

Bistable SME actuator with retainer

A heater strip (12) is disposed in spaced relation to a temperature responsive actuator element (20) for indirectly heating that element in response to current flow in the heater (12). An adjustable heat sink (22) is disposed in spaced proximity to the actuator element (20) for removing heat from the actuator element by radiation therefrom through air to the heat sink in a first position and adjustable to be in thermally conductive engagement with the actuator in a second position for increasing the efficiency of heat transfer from the actuator to the heat sink. Increased current flow in the protected branch circuit is required to cause the actuator (20) to attain its predetermined actuation temperature as the heat sink is adjusted to increase the efficiency of heat transfer between the actuator (20) and the heat sink.

Thermally actuated variable-rating circuit breaker having adjustable

A silicon substrate (2,22) having a SiO.sub.2 layer (4,24) grown on its upper surface and a metallization layer (6,26) of magnetic material subsequently deposited on the upper surface of the SiO.sub.2 layer is etched to define a cantilever beam (8,38) extending over a recess (12,32) in the substrate (2,22) having a magnetic layer (6,26) along the top surface thereof. The resulting structure is subsequently masked with a photoresist layer to enable a second layer (14,34) of magnetic material to be deposited on the first layer. The photoresist layer is stripped forming a second magnetic layer (14,34) projecting from the unsupported end of the cantilever beam over and spaced from a fixed stop (10,30) of magnetic material adjacent the unsupported end of the cantilever beam. In one version the magnetic material (6,14) serves as electrical current carrying contacts which close upon application of a magnetic field to the switching device. Alternatively, an additional layer (36) of better quality electrical conducting material may be bonded to the second magnetic layer (34) as a bridging contact (38) oriented at right angles to the major dimension of the cantilever beam (38) and a pair of contact surfaces (40,42) are bonded to the insulating layer (24) along lateral edges of the substrate (22).

Thin-film magnetically operated micromechanical electric switching device

A shutter 4 is movably mounted in a housing 6 for actuation between given positions by an SME (shape memory effect) element 8 in response to a given level of current flow through the SME element 8 causing I.sup.2 R heating of the latter above its transition temperature. The shutter 4 may be an indicator flag exposed by a window 10 in the housing 6, or may interrupt an optic beam 22.

SME shutter mechanism

A thermally responsive shape memory effect (SME) element (4) is positioned adjacent a fixed heater (40) for moving away from the heater to a switch actuating 'memory' position as current induced temperature increases, thereby establishing changes in heat transfer coefficient between the heater (40) and thermally responsive element (4) for each increment of movement. An intermediate switch actuating lever (22) is carried on a movable range adjustment lever (16) to vary pretravel of an SME driven plunger (12). The SME element is resettable against a fixed stop (2c) for achieving accurate repetitive resetting of the device.

Electrothermally actuated switch

A fluid jet ejector, such as is used in an inkjet printer head, is provided by a pair of spaced capacitor plates, one of which is a thin diaphragm, preferably of semiconductor material, such as silicon. The capacitor plates may be photolithographically developed. Impressing a time varying voltage on the capacitor causes the diaphragm to be set into mechanical motion. A reservoir containing fluid, such as ink, is contiguous the diaphragm and has a nozzle through which fluid exits responsive to diaphragm motion.

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Greendale, WI, United States of America

John W Kroll