> Perhaps a point of interest. > I'm currently putting boards in 2 Stwy Bs. One is a 20's piano & the > other an 1895ish. Any one who has looked at the bottom of the B has seen > no cut off bar but some amount of ribs that are whittled done > significantly in the bass corner with a flat maple stick running between > them. It has printed on it pulsator bar. patent 1878. No one has ever > been able to explain what the thing is for & in my mind promotes a > significant loss of stiffness. > I've always wondered what it was really for but in my mind it is > useless. for any reason I can see or hear. Sacrilege. CFT must be rolling over in his grave. In Patent 204,110 CFT refers to it as a sustaining-bar. 'Pulsator bar' must have come from the marketing department. According to CFT: 'The invention consists, first, in the combination, with a piano-forte sounding-board, of a sustaining-bar (one or more) arranged crosswise with relation to the ribs, and connected to the sounding-board, either above or below, at a distance from the bridge equal or nearly equal to the distance of the bridge from the opposite edge of the sounding-board, for the purpose of preventing the sounding-board from warping without disturbing its proper vibrations, and also forming a limit for the vibration; secondly, in the combination, with the sounding-board, of two coincident sustaining-bars, which are arranged crosswise to the ribs, and are fastened to said board, one above and the other below, at a distance from the bridge equal or nearly equal to the distance of the bridge from the opposite edge of the sounding-board the upper bar being metallic, and supported by cushions of wood, or other suitable material, for the purpose of preventing lateral movement of the ribs, and to increase the duration and strength of the sound.' He goes on to say: 'By the action of the sustaining-bar C the sounding-board is prevented from warping without disturbing the vibrations, and this effect is still further increased by the employment of the sustaining-bars C D, one above and the other below. Furthermore, by the metallic sustaining-bar D, the duration and strength of the sound are materially increased. My invention enables me to increase the area of the sounding-board without incurring the danger that such sounding-board will bulge up or sag down. I have found that by running the sustaining bar or bars out to the edges of the sounding-board the beneficial effect of the same is reduced.' Which would seem to indicate that he felt that turning this into a full cutoff bar would not be as 'beneficial' as having a 'sustaining-bar'. The illustration of the patent shows the metal bar above the board and a wooden bar below the ribs, although I have never actually seen a piano that looked like that. The patent does not mention or illustrate cutting down the ribs in the corner. Phil Ford > Oddly the older board had 14 ribs with the extra one in the treble end, > It had only 3 whittled down ribs & appeared to me from a design point of > view the stiffer idea. The 20's one had 5!! ribs whittled down with only > 13 ribs total. I suspect this board has been flat a really looonngg time. > The 1911 B & it's board I just sold & delivered was made without the > whittled down ribs. I ran the ribs full length to the bass corner with > the usual scallop. I have to say the sound was as good as any I've ever > heard & am convinced the extra crown support is far more important than > the devices purpose which is unknown & apparently unheard. > Cheers > Dale >
This PTG archive page provided courtesy of Moy Piano Service, LLC