The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Feb. 27, 1979

Filed:

Nov. 03, 1977
Applicant:
Inventor:

Sven H Johansson, Linkoping, SE;

Assignee:

Other;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ;
U.S. Cl.
CPC ...
166212 ; 175 94 ; 175 99 ; 299 31 ;
Abstract

A duct section or other load to be moved axially along a bore hole has two reciprocating drivers mounted on it and two sets of gripping elements. Each driver reacts axially between the load and a set of gripping elements to move the gripping elements relative to the load through a defined stroke in each axial direction. An endless cable with axially extending straight stretches has one stretch connected to each driver to constrain the drivers always to move in opposite axial directions and to begin and end their strokes simultaneously. The gripping elements are so formed that when engaged with the surface of a bore hole, increasing axial force on the load in one direction increases the radially outward force under which they bite into the surface. At each end of a driver stroke the gripping elements collide with abutment members of a direction control device, whereby gripping elements engaged with the bore hole surface are forced out of such engagement and disengaged gripping elements are forced against that surface. The abutment members are arranged in two sets, one set to coordinate gripping element engagement and disengagement for transporting the load in one axial direction, the other set for transportation in the opposite direction. Positioning the directional control device at one or the other limit of its rotation brings one or the other set of abutment members into use.


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