Woodworker's Journal 2009-33-2, страница 65
Lever-action Cam Clamps Like traditional instrument maker's cam clamps, lever-action clamps are quick and easy to tighten via their lever-activated cam lock. A good choice for general clamping duties around the shop, lever-action clamps are great for lamination work and big glue-ups where lots of clamps need to be installed quickly, before the adhesive sets. Jorgensen Gear Clamps and I .ever Clamps, as well as Bessey KlicKlamps, all feature a long tightening lever: the iar- Today's Shop continues on page 66... Parallel-head bar clamps have become the staple in many woodshops. Their large clamp heads won't mar the workpiece. When used with support blocks, they are very efficient for frame glue-up work. a bar, these clamps are tightened with a wood-, plastic- or rubber-coat-ed-handled handscrew that can generate impressive force. Handscrew bar clamps come in many different bar sizes and lengths. For versatility, it's best to invest in clamps in several sizes (for example, several each of 8- to 12-in., 16- to 18-in. and 24-in.-long clamps). For thick, heavy clamping, choose clamps with a deep reach, like Bessey's Tradesman series. Unlike the narrow fixed jaw on most handscrew clamps, the twin padded jaws on JET'S "DoubleHeader" clamps distribute pressure more evenly, making them very handy for gluing edge strips and moldings. Parallel-head Bar Clamps Although they tighten with only a handscrew, parallel-head bar clamps deliver enough clamping pressure for most everyday glue-up and assembly jobs. Models such as the JET Parallel, Jorgensen Cabinet Master and Bessey K-Body Revo clamps feature large plastic heads thai help distribute clamping pressure so they don't mar the work-piece, and they help keep rectilinear assemblies parallel. When used with clamp support blocks (see photo at top of page), parallel-head clamps provide a practical system for gluing up frames, doors, cabinets, boxes and more. Quick-action Clamps Yet another type of bar clamp, quick-action (also known as QA, trigger or quick-jaw clamps) are so lightweight and easy to tighten that they're "must-have" clamps for any modern shop. QA clamps have rein-forced-plastic clamping heads with rubber-padded jaws and feature a hand-pumped lever that closes and tightens the jaws, so you can set the clamp with one hand (Bessey's PowerGrip clamps are a hybrid, featuring both a pump lever to advance the jaws and a handscrew, for final tightening). A small button or lever instantly releases clamping pressure. Quick-action clamps come in many sizes as well as lengths, from the large 54-in. Jorgensen EZ Clamp II model to 4^-in. Gator mini clamps. In my shop, I've found the 6-in., 12-in. and 24-in. sizes to be the most useful for everyday clamping duties on my projects. Various QA clamp brands and models offer different features: The Stanley Fat-Max Extreme has a built-in power reel that automatically closes its jaws lightly when you press the release button. Most QA clamps allow their jaws to be reversed on the bar, for spreading work. Bessey DuoKlamps have a dial that reverses the direction of the jaws when the lever is pumped. WolfCraft's PowerCam clamp features a small pump lever that opens the jaws wider. The unusual Alpha Clamps features a second bar that slides in and out of the moveable jaw, making it a versatile choice for cabinet installations. Whether they're single- or double-headed, handscrew-tightened bar clamps have enough clamping power for everyday assembly and holding tasks. All models in the photo above offer the advantage of one-hand operation: The jaws tighten when you squeeze the grip. Woodworker's Journal April 2009 1 5 |
