METHODS FOR WEIGHING A PULLED OBJECT HAVING A CHANGING WEIGHT
Methods are disclosed for pulling an object while measuring the weight of the object. The object is pulled upward using a cable extending over a first cylinder. The cable further extends over a second cylinder. The cable travels along a cable path between an uppermost portion of each of the outer circumferential portions of the first cylinder and the second cylinder. The first cylinder is restrained from movement parallel to the cable path with an arm having a first end and a second end. The first end is coupled to the first cylinder and the second end is coupled to either the second cylinder or a frame. The weight of the object is measured with a force measurement device. In some embodiments, the position of the cable with respect to the frame may be adjusted by a dampening system or a bushing.
1 . A method for growing a silicon ingot comprising:
pulling the growing ingot using a cable extending over a first cylinder, the cable extending along a first axis from the growing ingot to one portion of the first cylinder and extending along a second axis orthogonal to the first axis from another portion of the first cylinder;
restraining the first cylinder from movement parallel to the second axis using an arm having a first end and a second end, the second end of the arm coupled to the first cylinder and the first end coupled to a frame; and
measuring the weight of the growing ingot.
2 . The method of claim 1 wherein measuring the weight of the growing ingot includes measuring the weight of the growing ingot with a force measurement device coupled to the first cylinder at a center axis of the first cylinder.
3 . The method of claim 1 further comprising extending the cable over a second cylinder after the cable extends over the first cylinder.
4 . The method of claim 1 further comprising controlling the position of the cable using a bushing.
5 . The method of claim 4 further comprising moving the bushing between a first position in which the bushing is in contact with the cable and a second position in which the bushing is not in contact with the cable.
6 . The method of claim 1 further comprising rotating the frame about the first axis.
7 . A method for growing a monocrystalline silicon ingot comprising:
pulling the growing ingot from a crucible of molten silicon along a first axis using a cable, the cable extending over a first cylinder rotatable about a center axis, the cable extending along the first axis from one portion of the first cylinder and extending along a second axis from another portion of the first cylinder;
restraining the first cylinder from movement parallel to the second axis with an arm having a first end and a second end, the second end coupled to the center axis of the first cylinder, the arm disposed parallel to the second axis; and
measuring the weight of the growing ingot.
8 . The method of claim 7 wherein measuring the weight of the growing ingot includes measuring the weight of the growing ingot with a force measurement device coupled to the first cylinder at the center axis of the first cylinder.
9 . The method of claim 8 wherein measuring the weight of the growing ingot with the force measurement device includes measuring the weight of the growing ingot with a load cell.
10 . The method of claim 7 further comprising the cable extending over a second cylinder after the cable extends over the first cylinder.
11 . The method of claim 10 wherein the cable extending over the second cylinder includes the cable extending over a spool, the cable coupled to at least a portion of the spool.
12 . The method of claim 7 further comprising controlling the position of the cable with a bushing, the bushing being movable between a first position in which the bushing is in contact with the cable and a second position in which the bushing is not in contact with the cable.
13 . A method for pulling an object upward comprising:
pulling the object upward using a cable, the cable extending over a first cylinder, the first cylinder having an outer circumferential surface, wherein pulling the object upward includes raising the first cylinder while restraining the cable from movement with respect to the first cylinder;
the cable further extending over a second cylinder, the second cylinder having an outer circumferential surface which the cable extends along the second axis, the cable travelling along a cable path between an uppermost portion of each of the outer circumferential portions of the first cylinder and the second cylinder;
restraining the first cylinder from movement parallel to the cable path with an arm having a first end and a second end, the first end coupled to the first cylinder and the second end coupled to at least one of the second cylinder or a frame; and
measuring the weight of the object with a force measurement device.
14 . The method of claim 13 wherein the object is a growing ingot.
15 . The method of claim 13 wherein raising the first cylinder while restraining the cable from movement with respect to the first cylinder includes raising the first cylinder with an actuator having a first end and a second end, the second end of the actuator coupled to the first cylinder.
16 . The method of claim 13 further comprising dampening at least one of pendular motion and orbital motion of the cable with respect to the frame using a bushing.
17 . The method of claim 13 further comprising dampening at least one of pendular motion and orbital motion of the cable with respect to the frame with a dampening system by displacing an upper section of a mounting member with a first mounting member actuator, wherein a lower section of the mounting member is pivotably coupled to the frame, and wherein the first cylinder, the second cylinder, and force measurement device are coupled to the mounting member.
18 . The method of claim 17 wherein dampening at least one of pendular motion and orbital motion of the cable with respect to the frame includes displacing the upper section of the mounting member in a first plane with the first mounting member actuator and displacing the upper section of the mounting member in a second plane with a second mounting member actuator.
19 . The method of claim 17 further comprising detecting a position of the cable with respect to the frame with at least one position sensor.
20 . The method of claim 19 further comprising, when the position of the cable deviates from a desired position, determining the amplitude and direction as a function of time of the upper section of the mounting member necessary to correct the position of the cable with respect to the frame.
21 . The method of claim 20 further comprising displacing the upper section of the mounting member by the determined amplitude and direction as a function of time with at least one of the first mounting member actuator and a second mounting member actuator.