Material testing system having improved hydraulic wedge clips
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorJames M Greer, Jr.
Life of this patent
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Abstract
A material testing system that uses at least one hydraulic grip is improved with cable clips that are attachable to a respective lateral side of each hydraulic grip wedge. Each cable clip has another end that extends to engage a cable(s) extending from a corresponding wedge retention spring hole. The cable(s) enable manual extension of a wedge retention spring for engagement and disengagement from the hydraulic grip wedge. The cable clip maintains the cable in a noninterfering position during operational use of the material testing system.
Claims5
A material testing system comprising:
- a load frame comprising:
- a base positioned on a support surface,
- a main actuator supported by the base and below a lower attachment fixture that is vertically actuated by the main actuator, and
- an upper fixture that is held at a distance from the lower attachment fixture;
- and
- at least one hydraulic grip that receives one end of a test specimen and that is positioned between and attached to one of:
- (i) the lower attachment fixture and the upper fixture and comprising:
- a fixture body having a wedge recess,
- a pair of hydraulic grip wedges received in opposition within the wedge recess, each hydraulic grip wedge having a pair of vertical wedge retention spring holes that are perpendicularly intersected respectively by a horizontal retention bolt hole,
- four retention springs having one end attached to the fixture body and another end extending upward respectively in the vertical wedge retention spring holes,
- a cable engaged to the other end respectively of each extension spring and extending out of the corresponding hydraulic grip wedge, enabling manual extension of the respective retention spring,
- at least two spring retention bolts received respectively in the horizontal retention bolt holes to attach to the other end of the wedge retention spring during extension by the corresponding cable, and
- four or more cable clips that are respectively attached at one end to a lateral side of one of the pair of hydraulic grip wedges and engaged at another end to a corresponding cable to maintain the cable in a noninterfering position.
A method comprising:
- attaching a fixture body of a hydraulic grip to one of a lower attachment fixture atop a main actuator and an upper attachment fixture attached to a crosshead of a load frame;
- attaching four wedge retention springs to a recess of the fixture body;
- passing respective one or more cables attached to each wedge retention spring through a corresponding vertical wedge retention spring hole in one of a pair of hydraulic grip wedges;
- with a respective wedge retention spring extended in the wedge retention spring hole by manual actuation of a corresponding cable;
- inserting a retention spring retention bolt through a horizontal bolt hole that intersects the vertical wedge retention spring hole;
- attaching one end of a cable clip respectively to each lateral side of the pair of hydraulic grip wedges;
- engaging another end of the cable clip to a corresponding cable to maintain the cable in a noninterfering position;
- engaging a test specimen between the pair of hydraulic grip wedges;
- and
- actuating the main actuator to materially test the test specimen.
Dependencies are inferred from the claim text.