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.
Patent No.:
Date of Patent:
Jul. 06, 1993
Filed:
Aug. 26, 1991
John M Curtis, Kittanning, PA (US);
Other;
Abstract
Grip apparatus for tensile strength testing of geosynthetic materials includes a pair of opposing first and second grip bars slidably mounted in a frame. Selectively operable locking elements carried on the frame and the first grip bar enable selective fixation of the first grip bar at a desired position with respect to the second grip bar when inserting or removing or loading test specimens. Various constructions of grip bars, and grip jaws mounted on the bars, are provided, including replaceable high friction surface rods, grip surfaces with alternating grooves and shoulder surfaces, and easily replaceable L-shaped grip jaws that do not require disassembly of the apparatus. A plurality of actuating shafts impart movement and grip forces to each grip bar, with the actuating pumps for the shafts being operable simultaneously, separately, synchronously or asynchronously. Preferred actuating pumps for the shafts include fluid driven pumps and, in particular, air actuated pumps providing internal transduction of the air pressure to hydraulic pressure and providing substantial amplification of actuating pressure delivered to the actuator shafts, with improved control in the incremental and decremental pressures applied.