When Chick Workholding's launched its One-Lok clamping system in the USA seven years ago as an alternative to the conventional machine vice, it introduced more precise workpiece positioning and a time-saving ratchet mechanism to adjust the position of the moveable jaw quickly. New lightweight versions have now been introduced to be marketed alongside it, offering users additional benefits. Availability in the UK is through 1st Machine Tool Accessories.
The latest One-Lok is available in two sizes rather than one, 400 or 500mm long, offering maximum gripping lengths of 180 and 280mm respectively. Further improvements include a lowering of the clamp profile from 150 to 134mm, which allows longer spindle travel in the Z-axis and also approximately halves the unit's weight for easier handling. To this end, an ergonomic handgrip has also been added at either end.
Sometimes, machinists turn a vice through 90° so that it lies transversely across the machine table. This can bring the part closer to the operator, but has the disadvantage that there is no clearance for the handle. With the new One-Lok, workholding in this orientation, although there is little need, has been made easier by use of a ratchet handle.
The moveable jaw can be adjusted quickly and conveniently, as it can now be slid using one hand rather than two over the QwikSlide ratchets. A few turns of the handle move the jaw in the same direction over the last few millimetres to complete the clamping action rapidly.
The existing BoltFast interface for the 152mm wide, interchangeable hard and stepped steel jaws and aluminium soft jaws has been retained. A quarter turn of the locking screw is all that is required to exchange them, promoting productivity when machining small batches of components.
As before, machining accuracy is enhanced by the enclosed design, which discourages swarf from accumulating, and by the mechanism's novel squeeze clamping action, which applies an equal and opposite force to both jaws and offers 20µ repeatability. It provides virtually deflection-free component clamping with a maximum retaining force of 26.7kN. On closure, the jaws impart a pull-down action to the workpiece for added security and precision.
Workholding evangelist, Paul Swann, Owner and President of Chick said, "With CNC plant costing six figures, you do not want it standing idle while an operator winds a traditional vice handle up to 70 times to secure a part.
"It is important to remember that production efficiency when machining small batches is driven by the operator loading and unloading the parts, rather than by the machine itself.
“In developing the new, lightweight One-Lok design in two variants, we took on board comments from many of the thousands of people using the original model.
"So customers buying the new type can expect enhanced functionality and even faster payback, typically three months in an average job shop, based on increased output from expensive machine tools."