Abstract: A shear coupling can be used with reciprocating and rotary pumps. The shear coupling uses a shear nut and connecting member as the shear element. The connecting member and shear nut are located inside the axial bore of the shear coupling to protect from corrosive wellbore elements. The coupling members may be connected by matching polygonal shaft and hub profiles on the coupling members to transmit torque. The shaft and hub may have octagonal profiles for better torque transmission capacity. The shear nut may be isolated from large alternating stresses due to pretensioning of the connecting member. The length of the connecting member, especially when pretensioned, and a reduced cross-section that may be formed on the outer surface of the shear coupling increase the overall flexibility of the shear coupling, thereby increasing the resistance to bending stress.

Abstract: A shear coupling can be used with reciprocating and rotary pumps. The shear coupling uses a shear nut and connecting member as the shear element. The connecting member and shear nut are located inside the axial bore of the shear coupling to protect from corrosive wellbore elements. The coupling members may be connected by matching polygonal shaft and hub profiles on the coupling members to transmit torque. The shaft and hub may have octagonal profiles for better torque transmission capacity. The shear nut may be isolated from large alternating stresses due to pretensioning of the connecting member. The length of the connecting member, especially when pretensioned, and a reduced cross-section that may be formed on the outer surface of the shear coupling increase the overall flexibility of the shear coupling, thereby increasing the resistance to bending stress.

Abstract: A shear coupling can be used with reciprocating and rotary pumps. The shear coupling uses a shear nut and connecting member as the shear element. The connecting member and shear nut are located inside the axial bore of the shear coupling to protect from corrosive wellbore elements. The coupling members may be connected by matching polygonal shaft and hub profiles on the coupling members to transmit torque. The shaft and hub may have octagonal profiles for better torque transmission capacity. The shear nut may be isolated from large alternating stresses due to pretensioning of the connecting member. The length of the connecting member, especially when pretensioned, and a reduced cross-section that may be formed on the outer surface of the shear coupling increase the overall flexibility of the shear coupling, thereby increasing the resistance to bending stress.

Abstract: A shear coupling can be used with reciprocating and rotary pumps. The shear coupling uses a shear nut and connecting member as the shear element. The connecting member and shear nut are located inside the axial bore of the shear coupling to protect from corrosive wellbore elements. The coupling members may be connected by matching polygonal shaft and hub profiles on the coupling members to transmit torque. The shaft and hub may have octagonal profiles for better torque transmission capacity. The shear nut may be isolated from large alternating stresses due to pretensioning of the connecting member. The length of the connecting member, especially when pretensioned, and a reduced cross-section that may be formed on the outer surface of the shear coupling increase the overall flexibility of the shear coupling, thereby increasing the resistance to bending stress.

Abstract: In a target apparatus, a coil spring lies on a linear axis and has open space between its adjacent coils. A sleeve disposed externally and rotatably around the coil spring includes a guide feature that reaches radially inward into the open space of the coil spring in a condition slidable along the coils. At least one arm carries a respective target plate on the sleeve at a radial distance outward therefrom. Impact of the target plate rotates the sleeve about the axis in a respective rotational direction, which causes translation of the sleeve along the axis in a respective translational direction due to cooperation between the coil spring and the guide feature on the sleeve. Use of a screw mechanism employing a coil spring instead of threads to cause translation of the sleeve under rotation thereof reduces the risk of functionally-detrimental damage to the screw mechanism by a firearm projectile.