Abstract: A sheave may include a body portion with a circular circumference and defining a center plane, a bore extending through the body portion and configured for receiving a shaft and allowing the body portion to rotate in the center plane, and a rope groove arranged on the circular circumference including a radiused bottom with a first end and a second end and a pair of opposing sidewalls each extending directly and tangentially from one of the first and second end and having a curved profile.

Abstract: A sheave may include a body portion with a circular circumference and defining a center plane, a bore extending through the body portion and configured for receiving a shaft and allowing the body portion to rotate in the center plane, and a rope groove arranged on the circular circumference including a radiused bottom with a first end and a second end and a pair of opposing sidewalls each extending directly and tangentially from one of the first and second end and having a curved profile.

Abstract: A clamp for clamping to two tubulars, each of the two tubulars including a component of a top drive system, the two tubulars threadedly connected together, the clamp for inhibiting relative rotation of the two tubulars, each of the two tubulars having at least one tubular projection projecting therefrom, the clamp including a clamp body having an interior surface, a plurality of clamp projections projecting inwardly from the interior surface of the clamp body for holding the at least one tubular projection projecting from each of the two tubulars.

Abstract: A clamp for clamping to two tubulars, each of the two tubulars including a component of a top drive system, the two tubulars threadedly connected together, the clamp for inhibiting relative rotation of the two tubulars, each of the two tubulars having at least one tubular projection projecting therefrom, the clamp including a clamp body having an interior surface, a plurality of clamp projections projecting inwardly from the interior surface of the clamp body for holding the at least one tubular projection projecting from each of the two tubulars.

Abstract: A clamp for clamping to two threadedly-connected items, and, in one aspect, two threadedly-connected components of a top drive system.

Abstract: A multi-seal sealing assembly with multiple seals so that when one seal wears out another can be moved into sealing position; and a top drive system for wellbore operations with such a sealing assembly; the sealing assembly in one aspect having a seal carrier movable to move at least one secondary seal into sealing position when a primary seal has worn out.

Abstract: A clamp for clamping to two threadedly-connected items, and, in one aspect, two threadedly-connected components of a top drive system.

Abstract: A multi-seal sealing assembly with multiple seals so that when one seal wears out another can be moved into sealing position; and a top drive system for wellbore operations with such a sealing assembly; the sealing assembly in one aspect having a seal carrier movable to move at least one secondary seal into sealing position when a primary seal has worn out.

Abstract: A digital voice pitch extractor is disclosed that determines the pitch frequency of human speech in real-time or at the same rate as it is uttered. The invention does not need the full bandwidth of the speech signal in order to perform its function. It will accept band-limited signals lacking fundamental pitch energy such as those from telephone channels. The signal can be severely degraded by added noise and the pitch extractor will still reliably determine the pitch.The invention includes a bank of contiguous bandpass filters. The outputs of each of the filters are converted to pulse trains and are summed to form a bi-phase harmonic histogram. The fundamental period is derived from the histogram and is verified by an error correction circuit.The circuit stability and accuracy needed to perform this task is achieved through the use of digital, as opposed to analog, electrical circuits in the main portion of the voice pitch extractor and the use of noise minimizing techniques.