Abstract: An earth drilling bit incorporating a bit wear indicator. The bit wear indicator includes: a sensor to detect wear at a selected point on the bit; a device for altering the resistance of the bit to receiving drilling fluid from the drill string; and, a tensioned linkage extending between the wear sensor and the flow resistance altering means. On detecting a predetermined degree of wear, the wear sensor releases the tension in the tensioned linkage. This activates the flow resistance altering device, causing the flow rate and/or pumping pressure of the drilling fluid to change. This serves as a signal that the predetermined wear condition has been achieved. The bit wear indicator can be adapted to monitor many different types of bit wear, including bearing wear in roller-cone type bits and gauge wear in all types of bits.

Abstract: An earth drilling bit incorporating a tensioned linkage type bit wear indicator. A tensioned linkage extends through the bit between a wear sensor and a device for altering the resistance of the bit to receiving drilling fluid from the drill string. On detecting a predetermined degree of wear, the wear sensor releases the tension in the tensioned linkage. This activates the flow resistance altering device, causing the flow rate and/or pumping pressure of the drilling fluid to change. The tensioned linkage passes through two intersecting passageways in the bit. A guide element is inserted at the intersection of the two intersecting passageways. The guide element routes the tensioned linkage between the two passageways.

Abstract: The present invention relates to a method and apparatus for detecting excessive wear of a rotatable bit used in drilling. In particular, the apparatus can detect loss of gauge or bearing failure in a bit. The method is accomplished by connecting a restricting means in the drill bit that can be manipulated to reduce the flow of drilling fluid through at least one port in the drill bit. A wire is connected between a sensor which senses wear and the restriction means to cause the restriction means to reduce the flow of drilling fluid and thereby signal the surface by the reduced flow as an indication of wear.

Abstract: A connector 10 is disclosed which is suited for use in effecting an electrical connection between separate conductor bundles 12, 16 in adjacent sections of a threadably sectioned conduit. The connector 10 is especially well suited for use in providing electrical continuity across a tool joint in a drill string. The connector 10 has first and second portions 20, 22 each adapted for placement in a corresponding connection portion of two connectable lengths of conduit. The first and second portions 20, 22 form a pin and box connection. Corresponding contacts 46, 80 on the first and second portions 20, 22 assume a conductive relationship in response to connection of the conduit. The contacts 46, 80 of each connector portion 20, 22 are radially symmetric about the axis of the conduit and are axially displaced one from the other. The contacts 46, 80 within the assembled connector 10 are isolated from the conduit environment.

Abstract: A side-entry sub for use in conjunction with wireline cable. The sub has a cable entry port provided with a self-closing valve for sealing the port upon withdrawal of the cable. In one embodiment, the self-closing valve is characterized by a housing member supporting a closure disc which is integrally molded with a resiliently deflectable support member having an elastic memory which biases the valve in the closed position. In an alternate embodiment, the self-closing valve comprises a ball valve, biased in the closed position by magnetic or spring means, and having a passageway through which the cable may pass. When the cable is inserted through the passageway, the ball valve is held in the valve open position. When the cable is removed from the passageway, the ball valve automatically closes.