Patent GB-190203617-A (GB)
Title: Improvements in and relating to Combined Electrical Piano Playing and Recording Attachment.
Inventor: DAVIS GEORGE HOWLETT
Filed: 1902-02-12
Granted: 1902-10-23
Abstract: 3617. Davis, G. H. Feb. 12. Automatic instruments; music recorders.-Relates to electric apparatus for playing keyboard instruments or for recording music played upon them by hand. A tunesheet 81, Fig. 5, made of electric insulating-material, passes from a storage roller 79 to a take-up roller 80 over a conducting-roller 87. The three rollers are mounted in a frame 73, which slides in another frame 72 sliding, in turn, on guides underneath the keyboard of the instrument. When in position for playing or recording, the roller 87 lies immediately beneath contact fingers 76 corresponding to the keys, and making contact with the roller 87 through holes in the tune-sheet when the apparatus is used for the former purpose. The frames are locked together by a catch 90, which engages with a notch 92 and can be disengaged by a trigger 96, wnich serves not only to pull out the frame 73 but also to depress the roller 87 out of contact with the fingers 76. Referring now to Fig. 1, the fingers close the circuits of electromagnets 7, the armatures 10 of which are carried by flat springs 8, and are connected by rods 9, Fig. 3, with pivoted blocks 13, the movements of which are communicated to the keys 18 by rods 16. The movement imparted to the armature 10 brings the corresponding block 13 into contact with a drum 1, which is rapidly rotated by an electric motor and thus gives the block the requisite motion. The blocks can be held out of engagement with the drum by a rail 19<b> operated by a hand-lever 22, when the instrument is used for recording. The apparatus comprises the following details:-(1) The speed of the tune-sheet is regulated by driving the roller 80 from a worm 126 splined on a shaft 124 having a wheel 121 engaging with a face-plate 120, which is driven by a band 118 from the drum 1. The shaft 124 can be moved longitudinally, so as to adjust the wheel 121 relatively to the face-plate, by a handle 59 connected through a series of links and levers with a collar 154 on the shaft. (2) The motor is arranged so that its commutator lies between the pole-pieces of its magnet and the core, the object being to save space. The bearing for the drum 1 is in the core. Its speed is regulated by a centrifugal governor, the balls of which cause an electric contact plate in series with the motor to rise and fall, and to make or break contact with a brush which can be adjusted by hand, so as to regulate the strength of the blow given to the keys. (3) A spring holder for the tune-sheet rollers by means of which it can be adapted for long or short rollers. (4) To convert the instrument into a recorder, a device shown in Fig. 14 is used. When the instrument is used for playing, the contact finger circuit comprises contacts 98, 104, 107, 103, and 99. The contacts 107 are carried on a bar maintained in the position shown in Fig. 14 by hand-operated cams 112. When released by these cams, springs 110 force the bar into the position shown in Fig. 1, and contact must now be made through the springs 157, 158 controlled by the keys. The recording-sheet is made of a semi-conducting material composed of paper impregnated with metallic particles ; it occupies the position of the tune-sheet and the heat generated by the electric current causes the fingers 76 to scorch marks on it corresponding to the notes played. Holes can then be punched out and the sheet, after preparation with shellac or the like, can be used as a tune-sheet.