Apparatus for capturing axial force on an inner drive member
AssigneeThe Charles Machine Works, Inc.
InventorMax A. Metcalf
Life of this patent
Estimating the term…
Abstract
A spindle with a mechanism for transferring axial force from an inner drive assembly to an outer drive assembly. The spindle's inner drive shaft is connected to an inner member of a dual-rod pipe by a drive rod having a sliding sleeve. The sleeve is fixed rotationally with the drive shaft, but not axially. When axial force drives the drive rod toward the drive member of the spindle, the sleeve contacts a stop member which is paired to the outer drive assembly. The stop member may be a pair of dowel pins. Axial force is thereby transferred from the inner member to the outer member, allowing such forces to be absorbed by the outer member's larger drive components.
Claims18
An apparatus for connecting to a dual-member drill string, comprising:
- an inner assembly including a drive shaft and a hollow sleeve, the hollow sleeve being configured for axial movement relative to the drive shaft;
- an outer assembly disposed about the inner assembly, wherein the outer assembly includes a structure extending into the interior space of the outer assembly, the structure configured to engage with the hollow sleeve upon its axial movement and transfer axial force from the inner assembly to the outer assembly;
- and
- a spring disposed between the drive shaft and the hollow sleeve, the spring biasing the hollow sleeve to a position away from the drive shaft.
A drilling apparatus for use with a dual-member drill string, comprising:
- an outer assembly configured to provide axial and rotational force to an outer member of the dual-member drill string;
- an inner assembly housed within the outer assembly, the inner assembly configured to independently provide rotational force to an inner member of the dual-member drill string, the inner assembly including a drive shaft and a hollow sleeve, the hollow sleeve being capable of axial movement relative to the drive shaft and in torque-transmitting relationship with the drive shaft;
- a stop member situated within the outer assembly, the stop member including a rod that extends through the outer assembly and is positioned to interact with the hollow sleeve at a limit of axial movement, wherein the stop member is configured to transfer axial force from the inner assembly to the outer assembly.
A dual-member spindle comprising:
- an outer assembly configured to provide axial and rotational force to an outer member of a dual-member drill string;
- an inner assembly configured to provide rotational force to an inner member of the dual-member drill string, the inner assembly comprising:
- a drive shaft;
- a hollow sleeve disposed about the drive shaft in sliding, torque transmitting relationship;
- a drive rod joined to the hollow sleeve, wherein the drive rod is configured for torque-transmitting engagement with the inner member of the dual-member drill string;
- and
- a spring disposed between the drive rod and the drive shaft;
- and
- a stop member disposed through the outer assembly, configured to provide a limit of axial movement of the hollow sleeve relative to the drive shaft.
Dependencies are inferred from the claim text.