>Anyone know if what, if anything, ever became of his idea? US patent 4,920,847 was granted to Harold in 1990. These pins were never put into production, and with the demise of Baldwin the patent eventually lapsed. I have some samples that Harold sent me and have tested them, as well as the general principles using hardware we put together in the lab. The idea is excellent, although sensitive to having exactly the right parameters and lubricant type (see Harold's patent testing) for long term torque stability, albeit with hundreds of repeated back and forth cycles (which a pin would not be subjected to in a piano application). I may use this type of pin in the new piano we're designing at UW. Stephen -- Dr Stephen Birkett Piano Design Lab Department of Systems Design Engineering University of Waterloo, Waterloo ON Canada N2L 3G1 tel: 519-888-4567 Ext. 3792 Lab room E3-3160 Ext. 7115 mailto: sbirkett[at]real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett
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