Link Clamps and Levers
Frequently Asked Questions
shape of the lever has a portion that is parallel to the clamp mounting flange, the workpiece contact surface is not parallel to the mounting flange. When clamping, the reaction force will put a force vector into the piston rod causing excessive bending stress and deflection. The workpiece contact surface must be parallel to the body mounting flange within +/-3°. I want to use a radius contact point on the end of my custom lever, what guidelines can you give me? Position the clamp so that it’s mounting flange is parallel to the workpiece contact surface within ±3°. Positioning the clamp so that the mounting flange is at an angle greater than 3° to the workpiece contact surface will cause excessive bending stresses to the rod resulting in premature failure.
What is the link clamp lever clamp angle? It is the angle of the clamping lever contact surface measured from the body mounting flange surface to the workpiece contact surface of the clamping lever. What is the acceptable lever clamp angle when clamping my workpiece? Levers should be designed and contact bolts should be adjusted so that the lever contact surface is within ±3° of parallel to the body mounting flange or 90° to mounting flange face when clamping a workpiece. Use a digital angle finder or
D-17
angle finder app on your smart phone to measure the angular position of the lever. It should be parallel to the body mounting flange or 90° to mounting flange face within ±3°.
E
PARALLEL TO MOUNTING SURFACE WITHIN 3º PARALLEL TO MOUNTING SURFACE WITHIN 3º
CORRECT CORRECT
PARALLEL TO SURFACES +/- 0.060” PARALLEL TO SURFACES +/- 0.060”
ILQA91600-5 REV B
CORRECT
ILQA91600-5 REV B
I want to clamp a workpiece with my lever at 20° from the mount flange, will it cause damage to the linkage mechanism or piston rod? Yes, a lever angle of greater than ±3° of parallel to the body mounting flange will cause excess force on the linkage mechanism and piston rod. Rapid, premature failure will result from excessive bending stresses in the rod. The lever must be positioned within the acceptable angle discussed in the second question.
HIGH DEFLECTION STRESSES
INCORRECT INCORRECT
HIGH DEFLECTION STRESSES
INCORRECT
ILQA91600-4 REV B
ILQA91600-4 REV B
I want to use an extended length lever, will I need to pressure reduce my link clamp similar to pressure reducing a swing clamp when using a long arm? No, link clamps are opposite of swing clamps when it comes to long arms. Link clamps can be operated at maximum operating pressure when extended levers are used. Assuming constant clamp pressure; increasing the distance between the contact point and link pivot or fulcrum creates less clamping force and less internal stresses in the linkage and pins. Reducing the distance between the contact point and link pivot produces greater clamping force and increased internal stresses in the linkage and pins. Therefore, if a shorter than standard length lever is used, the link clamp must be pressure reduced to avoid damage to the linkage mechanism. See the clamping force tables and graphs for the allowable lever length and operating pressure combinations.
I’ve designed my own custom lever with the workpiece contact surface at an angle to the clamp mounting flange. The lever shape also makes it parallel to the clamp mounting surface where it pins to the clamp linkage and plunger. Is it safe to use this lever? No, it is not safe to use the lever shown. Even though the
INCORRECT
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