What is claimed is:
1. A device used for testing a response of a material specimen to shear forces applied to the material specimen, said device comprising:
a base;
a first clamp attached to said base for clamping about a perimeter of the specimen in proximity to a distal end of the specimen;
a second clamp for clamping about the perimeter of the specimen in proximity to a proximal end of the specimen; and
flexures having a proximal and distal end, said proximal end of said flexures being attached to the second clamp at the proximal end of specimen, and said distal end of said flexures being attached to the first clamp at the distal end, whereby a force to the second clamp causes the proximal end of the flexures and the second clamp to move while the first clamp remains stationary, thereby applying a circumferential force against the specimen perpendicular to a longitudinal axis of said specimen.
2. The device as recited in claim 1, further comprising an actuator attached to said second clamp, wherein said actuator applies the force to said second clamp to thereby apply said circumferential force against the specimen.
3. The device as recited in claim 1, further comprising an actuator coupled to said first clamp, wherein said actuator applies a compression force against an end of said specimen.
4. The device as recited in claim 1, further comprising linear displacement transducers coupled to said second clamp to thereby measure the relative displacement between the first and second clamp when the circumferential force is applied to the specimen.
5. The device as recited in claim 1, further including means for controlling a temperature of the specimen.
6. The device as recited in claim 2, further comprising a control means for adjusting the force applied by the actuator to said second clamp and for monitoring a resulting displacement between the first and second clamps.
7. A device used for testing a response of a material specimen to shear forces applied to the material specimen, said device comprising:
a base;
holding means for clamping about a perimeter of the specimen in proximity to a distal end of the specimen and further clamping about the perimeter of the specimen in proximity to a proximal end of the specimen, wherein distal end of the specimen is held in a fixed position;
flexures having a proximal and distal end, said proximal end of said flexures being attached to said holding means between said proximal and distal ends, whereby a force to the proximal end of said holding means causes the proximal end of the flexures to move while the distal end remains stationary, thereby applying a circumferential force against the specimen perpendicular to a longitudinal axis of said specimen.
8. The device as recited in claim 7, further comprising an actuator attached to a proximal end of said holding means, wherein said actuator applies the force to said holding means to thereby apply said circumferential force against the specimen.
9. The device as recited in claim 7, further comprising an actuator coupled to a distal end of said holding means, wherein said actuator applies a compression force against an end of said specimen.
10. The device as recited in claim 7, further comprising linear displacement transducers coupled to said proximal end of said holding means to thereby measure the relative displacement between opposite ends of said holding means when the circumferential force is applied to the specimen.
11. The device as recited in claim 7, further including means for controlling a temperature of the specimen.
12. The device as recited in claim 8, further comprising a control means for adjusting the force applied by the actuator to said holding means and for monitoring a resulting displacement between opposite ends of said holding means.
13. A device used for testing a response of a material specimen to shear forces applied to the material specimen, said device comprising:
a base;
holding means for clamping about a perimeter of the specimen in proximity to a distal end of the specimen and further clamping about the perimeter of the specimen in proximity to a proximal end of the specimen, wherein distal end of the specimen is held in a fixed position;
flexures having a proximal and distal end, said proximal end of said flexures being attached to said holding means between said proximal and distal ends; and
an actuator, attached to a proximal end of said holding means, that applies a force to the proximal end of said holding means, whereby the proximal end of the flexures move while the distal end remains stationary, thereby applying a circumferential force against the specimen perpendicular to a longitudinal axis of said specimen.
14. The device as recited in claim 13, further comprising an actuator coupled to a distal end of said holding means, wherein said actuator applies a compression force against an end of said specimen.
15. The device as recited in claim 13, further comprising linear displacement transducers coupled to said proximal end of said holding means to thereby measure the relative displacement between opposite ends of said holding means when the circumferential force is applied to the specimen.
16. The device as recited in claim 13, further including means for controlling a temperature of the specimen.
17. The device as recited in claim 13, further comprising a control means for adjusting the force applied by the actuator to said holding means and for monitoring a resulting displacement between opposite ends of said holding means.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A device (40) for moving elevator doors (26), comprising:
a threaded ferromagnetic shaft (42);
a motor (44) that selectively rotates the shaft; and
at least one magnetic mover (48) adapted to be supported for movement with a door (26), the magnetic mover generating a magnetic field that causes the mover to move responsive to rotation of the shaft.
2. The device of claim 1, wherein the magnetic mover (48) comprises ferromagnetic members (50) on opposite sides of the shaft, each ferromagnetic member having a contoured surface (54) facing the shaft and a field generator (52) that selectively generates the magnetic field such that it passes from the contoured surfaces through the corresponding threads (56) on the shaft.
3. The device of claim 2, wherein the field generator (52) comprises at least one of a conductive wire coiled about a portion of the ferromagnetic members or a magnet.
4. The device of claim 2, wherein the contoured surfaces (54) include threads and including a nonmetallic filler (60) in spaces between the threads on the mover ferromagnetic members (50).
5. The device of claim 4, including a nonmetallic filler (62) in spaces between the threads on the shaft (42).
6. The device of claim 1, including a controller (46) that selectively varies a strength of the magnetic field of the mover (48) to thereby control movement of the mover relative to the shaft (42).
7. The device of claim 6, wherein the controller (46) controls the field to move the mover faster in a door opening direction than in a door closing direction.
8. The device of claim 6, wherein the controller (46) uses an indication of longitudinal movement of the mover (48) relative to the shaft (42) not corresponding to rotation of the shaft and responsively controls at least one of the motor or the magnetic field.
9. The device of claim 8, including at least one sensor (58) that provides an indication of slipping between the mover and the shaft to provide the indication of relative longitudinal movement.
10. The device of claim 1, wherein the shaft (42) has a first portion with a thread pitch in one direction and a second portion with a thread pitch in an opposite direction such that movers (48) associated with the first and second portions move in opposite directions responsive to rotation of the shaft.
11. The device of claim 1, including a controller (46) that causes the motor (44) to rotate the shaft (42) faster in a door opening direction than in a door closing direction.
12. The device of claim 1, wherein the mover (48) comprises a permanent magnet (58).
13. An elevator door assembly, comprising:
at least one door (26) that is moveable between an open and a closed position;
a threaded ferromagnetic shaft (42);
a motor (44) that selectively rotates the shaft; and
at least one magnetic mover (48) supported for movement with the door, the magnetic mover generating a magnetic field that causes the door to move between the open and closed positions responsive to rotation of the shaft.
14. The assembly of claim 13, wherein the magnetic mover (48) comprises ferromagnetic members (50) on opposite sides of the shaft, each ferromagnetic member having a contoured surface (54) facing the shaft and a field generator (52) that selectively generates the magnetic field such that it passes from the contoured surface (54) through the corresponding threads (56) on the shaft (42).
15. The assembly of claim 13, including a controller (46) that selectively varies a strength of the magnetic field of the mover (48) to thereby control movement of the mover relative to the shaft (42).
16. The assembly of claim 13, including two doors (26) each having at least one associated mover (48) and wherein the shaft (42) has a first portion with a thread pitch in one direction associated with one of the doors and a second portion with a thread pitch in an opposite direction associated with the other door such that the doors move in opposite directions responsive to rotation of the shaft.
17. A method of moving an elevator door (26) that has a magnetic mover (48) associated with the door, the mover interacting with a threaded ferromagnetic shaft (42), comprising the steps of:
selectively rotating the shaft (42); and
generating a magnetic field that causes the mover (48) and the door (26) to move longitudinally parallel to the shaft responsive to rotation of the shaft.
18. The method of claim 17, including selectively varying a strength of the magnetic field.
19. The method of claim 17, including increasing a speed of rotation of the shaft (42) and a strength of the magnetic field when the door (26) is moving from a closed position toward an open position.
20. The method of claim 17, including determining whether the mover (48) moves longitudinally relative to the shaft other than responsive to rotation of the shaft (42) and responsively changing one of a speed of rotation of the shaft or a strength of the magnetic field when there is such relative movement.