A new power impact tool design has been developed and tested using advanced engineering polymers to replace traditional metal components. The new polymer-metal impact mechanism generates less noise, lower vibrations, and potentially reduces biomechanical injuries. Power tools are known to cause several medical ailments including Hand-Arm Vibration Syndrome (HAV), Raynaud's phenomenon, and Vibration White Finger unless the daily exposure and/or dosage is limited. To evaluate the effects of a polymer-metal impact mechanism on tool performance, a non-linear model describing the equations of motion and resulting output forces were developed. In addition, a number of experiments with a high frequency Instron test machine and prototype tools were performed to validate the model and compare performance of conventional power tools to the new polymer based design. The results show that although adding a polymer does reduce noise and vibration, the reduction in impact force is relatively small and statistically insignificant. Various polymer materials and shapes were evaluated and results show that for durability and performance, the optimum appears to be a plug inserted in a cavity in either the piston or the cutting tool, thus creating a state of confined compression on the polymer. The polymer used in this research was Minlon® (mineral reinforced Nylon66), and durability was improved when the polymer inserts were cycled with compressive loads before use in the power tool.

1.
United States Department of Labor, Bureau of Labor Statistics. 2004. Survey of Occupational Injuries and Illnesses in cooperation with participating State agencies. U.S. Bureau of Labor Statistics Postal Square Building, 2 Massachusetts Ave., NE, Washington, DC 20212-0001
2.
United States Navy, Navy Safety Center. Acquisition Safety Vibration. Naval Safety Center, 375 A Street, Norfolk, VA 23511
3.
United States Department of Labor, Occupational Safety & Health Association, (1999). Proposed Ergonomics Program, Federal Registrar #64:65768-66078. U.S. Department of Labor Occupational Safety & Health Administration, 200 Constitution Avenue, Washington, D.C. 20210.
4.
The Health and Safety Executive (HSE), Hand-Arm Vibration - Advice for Employees. Publication No. INDG296(rev1). Health and Safety Executive, Rose Court, 2 Southwark Bridge, London, SE1 9HS
5.
Barab, J. 2002. Lies, Partisanship Caused Ergo Standard to Crumble. Safety and Health Magazine, February, 2002.National Safety Council, Safety and Health, 1121 Spring Lake Drive, Itasca, IL 60143-3201
6.
Glancey, J.L., J. Moore, D. Muhlenforth, J. Lawrence, (2004). Measurement of Manual and Power Impact Tool Vibration Transmission to the Hand. Paper No.047027. Written for Presentation at the 2004 ASAE/CSAE Annual International Meeting, Ottawa, Ontario, Canada.
7.
Glancey, J.L., P. Popper (Dupont), T. Nasr, P. Truitt, M. Orgovan, D. O’Brian, (2003). Design and Performance of Hand-Struck Impact Tools Using High Performance Engineering Polymers. Paper No. IMECE2003-41455. Proceedings of the 2003 ASME International Annual meeting, Washington, D.C.
8.
The Dupont Co., 2006. Product Information, Dupont Minlon 11C40 NC010. Product Sheet No. 050722. The DuPont Co., Wilmington, DE.
9.
Bovenzi, Massimo. 2006. Hand-Transmitted Vibration. Encyclopedia of Occupational Health and Safety, 4th Ed. International Labour Office 4, route des Morillons CH-1211 Geneva 22 Switzerland.
10.
Glancey, J.L., P. Popper, J. Moore, D. Muhlenforth, and T. Nasr. 2004. Modeling and Experimental Evaluation of Hand and Power Tools Vibration Transmission to the Hand and Arm. ASAE Paper 047027. ASAE, 2959 Niles Road, St. Joseph, MI 49085-9659.
11.
International Standards Organization. 1986. ISO Standard 5349: Mechanical vibration - Guidelines for the measurement and assessment of human exposure to handtransmitted vibration, International Organization of Standards, Geneva, Switzerland.
12.
Glancey, J.L., P. Popper (Dupont), M. Mitch, P.Truitt, T. Nasr, M. Orgovan, J. Stevens. 2003a. A new cyclic impact device and standard testing methodology for hand struck tools. Paper No. IMECE2003-41451. Proceedings of the 2003 ASME International Annual Meeting, Washington, D.C.
13.
Konchar, J. 2006. Mathematical modeling and testing of a new polymer-based impact tool design to reduce vibration-related biomechanical injuries. Degree with Distinction Thesis, University of Delaware, Newark, DE.
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