US 2022/0090292 A1 · ACTIVE BALANCING SEED LIFT

Abstract

A crystal growing system includes a rotating seed lift assembly to rotate and lift a seed crystal supported by a cable. The seed lift assembly includes a spool that rotates to wrap the cable around the spool, thus raising the cable. As the spool rotates, it moves in an axial direction to avoid displacing the cable in the axial direction. A leadscrew in a counterweight assembly is mechanically coupled to the spool via a coupling (e.g., a sprocket-and-chain coupling coupled to the spool spindle). As the spool rotates, the leadscrew thus rotates at a rate proportional to the spool's rate of rotation. A movable counterweight driven by the leadscrew is thus driven to move in a direction opposite the axial direction (e.g., opposite the movement of the spool). The counterweight assembly is thus configured to offset center-of-mass changes that would have otherwise been introduced by movement of the spool.

Claims20

Dependent claims

A seed lifting assembly comprising:

a platform base having a cable port for outputting a cable supporting a seed crystal;
a spool having a helical collection groove extending along a length of the spool, the spool rotatable about an axis of rotation to wind the cable into the collection groove as the spool moves longitudinally along a spool axis;
and
a counterweight assembly coupled to the platform base, the counterweight assembly including:
a counterweight leadscrew rotatably coupled to the spool such that rotation of the spool induces rotation of the counterweight leadscrew;
and
a movable counterweight coupled to the counterweight leadscrew, wherein rotation of the counterweight leadscrew induces sliding of the movable counterweight along a counterweight axis that is parallel to the spool axis;
and
wherein, in response to longitudinal movement of the spool in a first direction, the counterweight assembly is configured to slide the movable counterweight in a direction opposite the first direction by an amount sufficient to offset any center of mass displacement induced by the longitudinal movement of the spool.

6 more elements

A crystal growing system, comprising:

a growth chamber having a crucible containing a melt;
a seed crystal suspended within the growth chamber by a cable along a cable centerline;
and
a seed lift assembly rotatably coupled to a top end of the growth chamber and having an assembly center of mass along the cable centerline, the seed lift assembly supporting the cable within the growth chamber, the seed lift assembly having a spool for raising the cable and having a movable counterweight, the spool having a spool center of mass that moved with respect to the cable centerline as the cable is raised, the movable counterweight having a counterweight center of mass, wherein the movable counterweight is mechanically coupled to the spool such that movement of the spool center of mass with respect to the cable centerline induces coordinated movement of the counterweight center of mass such that the assembly center of mass remains along the cable centerline.

1 more element

A method for growing a crystal, comprising:

lowering a seed crystal to a melt by a cable supported by a seed lift assembly, the cable having a cable centerline;
and
simultaneously rotating the seed lift assembly and raising the cable, wherein raising the cable includes:
raising the cable via movement of a component of the seed lift assembly, wherein movement of the component causes a center of mass of the component to be moved with respect to the cable centerline;
and
automatically moving a movable counterweight in response to movement of the component, wherein the movable counterweight is mechanically coupled to the component such that movement of the center of mass of the component with respect to the cable centerline is offset by movement of a counterweight center of mass to maintain a center of mass of the seed lift assembly along the cable centerline.

3 more elements

Dependencies are inferred from the claim text.

Active balancing seed lift

Life of this patent

Active balancing seed lift

Life of this patent

Abstract

Claims20