Abstract: A drill bit having one or more nozzle retention bodies attached by a single orientation mounting is disclosed, as is the associated method for its manufacture. The upper end of the nozzle retention body has a fluid inlet in communication with the internal fluid plenum of the drill bit, and the lower end of the nozzle retention body includes a fluid outlet that defines an exit flow angle. The exit flow angle is angularly disposed from the longitudinal axis of the drill bit. The nozzle retention body may advantageously be chamfered or the like to provide a reduced cross-sectional area at the lower end of the nozzle retention body. The outer surface of the nozzle retention body (and attached hardened elements) may extend substantially to gage, or may fall short of that diameter.

Abstract: A multi-stage diffuser nozzle for use as a drill bit nozzle jet includes a flow restriction portion upstream of a fluidic distributor portion, and also preferably includes a transition region between these two. The flow restrictor communicates with the interior fluid plenum of a drill bit and is used to limit or choke the total flow of drilling fluid by having a relatively small cross-sectional area for fluid flow. The fluidic distributor communicates with the flow restrictor and reduces the exit flow velocities of the drilling fluid as the drilling fluid is ejected from the nozzle by providing a relatively larger cross-sectional area for fluid flow. The fluidic distributor also directs the flow paths of the drilling fluid to advantageous locations such as cone surfaces that are prone to bit balling. The transition region is an area that dampens fluid pressure oscillations in the drilling fluid.

Abstract: A nozzle and retainer assembly is provided for use in a rotary cone earth boring bit that allows for a larger internal passage in the nozzle. In one aspect, the assembly has a nozzle seated on a shoulder in a receptacle with a stepped portion extending radially outward with a first nozzle shoulder spaced from and facing toward the shoulder in the receptacle to partially define a seal gland. The stepped portion has a second nozzle shoulder facing toward the open end of the receptacle and the retainer engages the inside surface of the receptacle and the second nozzle shoulder to retain the nozzle in the receptacle.

Abstract: A nozzle retention receptacle for rotary cone rock bits consists of a nozzle retention receptacle body forming a fluid passage therethrough. The body forms a first upstream entrance end that forms part of a wall of a plenum formed within a rock bit body and a second downstream exit end. The upstream end further forms a mounting interface that circumvents a fluid entrance port to the passage in the nozzle retention receptacle. The port communicates with the fluid plenum in the bit body. The body of the rock bit further forms a nozzle retention receptacle mounting interface that is common to the mounting interface formed by the nozzle retention receptacle.

Abstract: A nozzle sleeve for the retention of replaceable fluid nozzles for rock bits is disclosed. The sleeve is secured within the body of the rock bit. A first upstream end of the sleeve communicates with a fluid plenum formed by the bit body. A second downstream end of this sleeve is adapted to receive the fluid nozzles. An elliptical fluid entrance is formed at the first upstream end of the nozzle sleeve. The elliptical fluid inlet formed by the sleeve serves to increase the flow of fluid to the nozzles, reduce turbulence of the fluid and substantially reduce the erosive effects associated with high fluid velocities and turbulent flow.

Abstract: A composite mini-extended nozzle is disclosed that is designed to both resist erosion and be strong enough to withstand the shock of a downhole drilling environment. In addition, means are provided to shroud at least a portion of the extended nozzle to further protect a portion of the nozzle nearest the exit plane from downhole obstructions. A combination of materials used to form the nozzle may include a matrix of tungsten carbides with suitable binder joined to an outer metal jacket nozzle body. A third ceramic matrix material may be utilized to line or partially line an interior passage formed by the mini-extended nozzle and a reduced in diameter portion of the nozzle design may include a built-in fracture plane in the unlikely event the end of the nozzle hits an obstruction. The extended portion of the nozzle will shear off along this fracture plane thereby preventing a nozzle washout that likely would result in a trip out of the hole to repair the resultant damage to the rock bit.

Abstract: Displayed ECG waveforms are maintained within acceptable aspect ratios without rapid fluctuation in amplitude by rapidly decreasing the gain of the signal channel by discrete amounts as the peak-to-peak amplitude of the ECG signal increases through each of a number of levels and by increasing the gain of the signal channel only after the peak-to-peak amplitude of the ECG signals has dropped to a given fraction for a predetermined period of time.

Abstract: Special circuitry in the transmitter of an electrocardiograph (ECG) telemetry system detects various malfunctions of the system and changes the transmitted signal to indicate their presence to the system receiver. When the transmitter detects that an input electrode has become detached from the patient, it changes the frequency of the subcarrier signal to indicate this problem to the receiver. The receiver monitors the subcarrier frequency and flashes an alarm light when the frequency corresponds to the electrode inoperative condition.

Abstract: A nozzle sleeve for the retention of replaceable fluid nozzles for rock bits is disclosed. The sleeve is secured within the body of the rock bit. A first upstream end of the sleeve communicates with a fluid plenum formed by the bit body. A second downstream end of this sleeve is adapted to receive the fluid nozzles. An elliptical fluid entrance is formed at the first upstream end of the nozzle sleeve. The elliptical fluid inlet formed by the sleeve serves to increase the flow of fluid to the nozzles, reduce turbulence of the fluid and substantially reduce the erosive effects associated with high fluid velocities and turbulent flow.