GB898250A - Improvements in or relating to upright pianos - Google Patents

Abstract

898,250. Pianofortes. EAVESTAFF & SONS Ltd., W. G. Dec. 30, 1960 [Sept. 30, 1959], No. 33234/59. Class 88 (2). The bottom door 15 of a piano is mounted so that the angle between the door and the soundboard 11 can be varied to control the intensity of the sound reflected towards the top lid of the piano. In Fig. 1, the bottom door pivots about a channel 17 formed by a stepped plinth 18 and a plate 19. The top edge of the door held by a rack 21 pivoted at 22 and urged downwards by a spring 32. The rack is formed with two grooves 26, 27 and is fitted with a block 31 to define three angular positions of the door. Downward movement of the rack is limited by a hook stop 25 which projects through a slot in the rack. In Fig. 2, the inclination of the bottom door is controlled by a linkage 37, 38, 39 with a handle 36 at one end of the keyboard. The door may be held in intermediate positions by means of a rack 42 engaging a pawl on the handle 36 or by a rack engaging the top of the door as before. The door may be pivoted on pins 46 projecting from the piano side walls and engaging pivot blocks 44 on the door. A cam (not shown) on the face 43 may engage the handle to close the door when the face is closed. In Fig. 3 (not shown), the bottom door is coupled to the top lid 52, a rack being provided as in Fig. 1. In all the embodiments, frictional brakes or shoes may be used to hold the bottom door in an intermediate position.