Posted By Martin Taylor Hiya hope somebody can give me some ideas to help on this one. As part of our assembly process we use a high torque nut spinner - you know the type with a long hand and then a drive shaft at 90degrees to the handle and a socket on the end to torque the nut up. The design of this is such that operators need to hold the tool with one hand opn the handle (and the trigger mechanism) and the other on the rotating shaft - allowing the rotating shaft to turn free in the hand. Over time this has been developed to fit a free spinning cover over the driven spindle which is now the holding point. Unfortunately this gives rise to a small gap at either end which recently led to an accident when a strand of glove got caught in the gap and twisted the operator finger causing a broken little finger. The team are now looking to ways to encourage operators to hold the protective sleeve at it's mid point - well away from any risk of trapping (I do wish they would have a CAD link to this website). The problem now is that operators complain about the vibration holding it this way and I have been asked if I can source any antivibration material that could be formed into a sleeve around the rotating shaft. It's a long shot but does any body know of such material - alternatively does anybody have a safer way of handling high torque nut spinners with extended shafts thanks martin

Posted By Merv Newman Martin, I consult for a Renault car plant (2 200 cars a day, 6 500 employees, 1 500 agency employees) and I think I know exactly the problem you have. Before my very eyes an operator managed to sprain all four fingers of his left hand. I did learn some useful new words in French. He was bolting on the front bumper of a Scenic car, using a pneumatic nut spinner with a 20 cm right angle extension. the nut spinner was held by his right hand, which actioned the trigger, his left hand supported the extension. Gloves being worn were synthetic knit fabric with a plastic / rubber coating to aid grip. These gloves had been adopted as standard for almost all "mechanical" operations on the assembly line. Friction between the left hand glove and the extension caused the glove to bind on to the extension, compressing the hand and tearing the glove between each of the fingers. Subsequent to the accident the length of the extension was reduced to 5cm and operators were retrained to support the nut spinner with both hands and to not hold the extension. Incidental information perhaps, the operator had four bolts to place. The first was put on the extension and the other three were held between the fingers of his left hand. He was on the last bolt when the accident happened. This may not be a direct answer to your question, but I hope it helps. If any one wants to know the new words I learned, please e-mail me direct.

Posted By Peter Longworth A powered nut spinner eh. They think of everything nowadays. These teenagers don't know how lucky they are.

Posted By Chris Pope Why don't you ask the HSE for a solution - they have done extensive research on reducing vibration.