In-head Wedge Grips (Cable)
Designed as an integral part of the testing platform, cable wedge grip jaws fit directly into the crosshead pocket of the frame. Cable grip jaws are only available for load frames with a capacity of 600 kN (135,000 lbs) or more. These jaws are rugged heat treated steel and ideal for testing stranded cable specimens.
The wedge design causes the gripping force to increase as tension force is applied. This ensures a secure gripping action with minimal slippage throughout the range of the test.
Filler plates are provided with the purchase of testing frames and allow a variety of specimen thicknesses to be tested. The filler plates adjust the opening of wedge jaws by changing the width of the crosshead pocket. All plates should be used for the thinnest specimens and no filler should be used for the thickest specimens.
Principle Of Operation
A pair of wedge grip jaws is used in each crosshead pocket to grip the upper and lower end of the specimen. The grip jaw pairs are actuated (opened and closed) by one of two basic methods: pinion or lever arm. The method used depends on frame model and frame options purchased. To use cable grip jaws, jaw actuation must be accomplished hydraulically, regardless of actuation method (i.e. hydraulically operated pinions or hydraulic lever arm).
When pinion actuation is used, the back surface of each grip jaw is equipped with rack teeth to facilitate actuation of the jaws in the crosshead pocket. A pinion meshes with these rack teeth and as the pinion is actuated by the operator, the jaws are raised or lowered in the crosshead pocket.
When lever arm actuation is used, a grip hanger is attached to each grip jaw with two bolts. Once the jaws are installed in the grip pocket, the grip hangers will pivot about a lever arm. As the operator actuates the lever arm, the jaws are raised or lowered in the crosshead pocket.
Once the specimen has been inserted between the jaws, the operator applies an initial clamping force to the specimen with the pinion or lever actuators (depending on frame options). When the test is begun, the wedge design of the grip jaws and pocket translates some of the tension force applied by the load frame into a gripping force on the specimen. As the tension force increases so does the gripping force, this reduces instances of specimen slippage.
Application Range
- Jaws are rated to full machine capacity - up to 3000 kN (600,000 lbf, 300,000 kgf)
- Designed for testing specimens in compliance with ASTM E8 standards
- Wedge design causes gripping force to increase as more tension force is applied
- Rugged heat treated steel design for minimum maintenance and durability
- Filler plates allow the user to test a range of specimen thicknesses with the same set of jaws
Accessories
| Item Name | Capacity | Specimen Diameter | Cat # |
|---|---|---|---|
| In-Head Cable Grip Insert Holders for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | W-1538 | |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 19.05 mm 0.75 in | W-1538-E |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 13.20 mm 0.52 in | W-1538-G |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 12.70 mm 0.5 in | W-1538-C |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 15.24 mm 0.6 in | W-1538-H |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 11.11 mm 0.4375 in | W-1538-B |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 12.90 mm 0.51 in | W-1538-F |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 15.88 mm 0.625 in | W-1538-D |
| In-Head Cable Grip Inserts for Testing 7 Strand Wire | 2,000 kN 450,000 lbf | 9.53 mm 0.375 in | W-1538-A |