Tri-cam axial extension to provide gripping tool with improved operational range and capacity

• US 8,424,939 B2
• Filed: 07/17/2009
• Issued: 04/23/2013
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: Noetic Technologies Inc.
• Original Assignee: Noetic Technologies Inc.
• Inventors: Slack, Maurice William
• Primary Examiner(s): Chin, Paul T
• Application Number:
  US12/505,446
• Publication Number:
  US 20090273201A1
• Time in Patent Office: 1,376 Days
• Field of Search: 294/86.25, 294/86.21, 294/86.22, 294/86.23, 294/86.26, 294/86.27, 294/86.3, 294/86.15, 294/86.31, 175/425, 166/77.52, 166/77.53
• US Class Current: 294/86.25
• CPC Class Codes: E21B 19/07 Slip-type elevators

Abstract

An improvement in a gripping tool having a grip surface carried by movable grip elements and cam linkages to radially move the grip surface from a retracted to an extended position. The improvement involves a tri-cam linkage with cam pairs supporting bi-rotary to axial stroke activation and further cam linkages to cause radial stroke of the tool grip surface as a function of axial stroke.

Claims

1. An improvement in a gripping tool having a gripping assembly with a grip surface carried by movable grip elements to radially move the grip surface from a retracted to an extended position, the gripping assembly being activated by axial movement, the improvement comprising:

a tri-cam linkage comprising a drive cam body, a driven cam body and at least one intermediate cam body, the drive cam body and the at least one intermediate cam body providing a drive cam pair with a cam surface on the drive cam body engaging a first cam surface on the at least one intermediate cam body, the at least one intermediate cam body and the driven cam body providing a driven cam pair with a second cam surface on the at least one intermediate cam body acting in opposition to the first cam surface and engaging a cam surface on the driven cam body, the tri-cam linkage acting between a body of the gripping tool and the gripping assembly translating bi-rotary movement in either a clockwise or counterclockwise direction of the body relative to the grip surface into axial movement to drive axial stroke activation of the gripping assembly.

3. The improvement of claim 1, wherein the tri-cam linkage is arranged with a latch that when engaged will prevent axial stroke activation of the tri-cam linkage.

4. The improvement of claim 3, wherein the tri-cam linkage is provided with a mechanical lockout comprising a lockout dog on one portion of the latch and a mating lockout dog pocket on another portion of the latch that when activated prevent engagement of the latch.

2. An improvement in a gripping tool having a gripping assembly with a grip surface carried by movable grip elements to radially move the grip surface from a retracted to an extended position, the gripping assembly being activated by axial movement, the improvement comprising:

a tri-cam linkage comprising a drive cam body, a driven cam body and at least one intermediate cam body, the drive cam body and the at least one intermediate cam body providing a drive cam pair with a cam surface on the drive cam body engaging a first cam surface on the at least one intermediate cam body, the at least one intermediate cam body and the driven cam body providing a driven cam pair with a second cam surface on the at least one intermediate cam body acting in opposition to the first cam surface and engaging a cam surface on the driven cam body, the tri-cam linkage acting between a body of the gripping tool and the gripping assembly translating bi-rotary movement in either a clockwise or counterclockwise direction of the body relative to the grip surface into axial movement to drive axial stroke activation of the gripping assembly;

wherein the drive cam pair is arranged to only be active to cause axial stroke as a function of rotation under a first direction of rotation and the driven cam pair under the second direction of rotation, which separation of bi-rotary activation into two cam pairs facilitates providing greater axial stroke and correlatively radial stroke of the grip surface than is possible where a single cam pair is employed in a bi-rotary activated linkage.

5. A gripping tool, comprising:

at least one body including an associated load adaptor adapted to be connected to and interact with one of a drive head or reaction frame;

a gripping assembly carried by the at least one body and having at least one grip surface adapted to move from a retracted position to an engaged position to radially engage the grip surface with a work piece upon relative axial displacement of the at least one body relative to the grip surface in at least one axial direction; and

a tri-cam linkage acting between the at least one body and the gripping assembly, the tri-cam linkage comprising a drive cam body, a driven cam body and at least one intermediate cam body, the drive cam body and the at least one intermediate cam body providing a drive cam pair with a cam surface on the drive cam body engaging a first cam surface on the at least one intermediate cam body, the at least one intermediate cam body and the driven cam body providing a driven cam pair with a second cam surface on the at least one intermediate cam body acting in opposition to the first cam surface and engaging a cam surface on the driven cam body, the tri-cam linkage translating bi-rotary movement in either a clockwise or counterclockwise direction of the load adaptor relative to the grip surface into axial movement to drive axial stroke activation of the gripping assembly.