Patent GB-351910-A (GB)
Title: Synchronizing device for musical instruments or other apparatus
IPC: G10F5/02
Filed: 1929-12-23
Abstract: 351,910. Synchronizing automatic musical instruments or the like with Kinematographs &c. AUBRY, E., 200, Rue Lafayette, Paris, and BOREAU, G., 5, Rue Baillot-Reviron, Versailles, Seine-et- Oise, both in France. Dec. 23, 1929, No. 39320. Convention date, Feb. 4. Void [Published under Sect. 91 of the Acts]. Addition to 284,283, [Class 40 (ii), Phonographs &c.]. [Class 40 (ii).] The electropneumatic system described in the parent Specification, for synchronizing the working of two or more automatic musical instruments or other apparatus, each controlled by a perforated paper roll, is modified to adapt it for synchronizing one or more instruments controlled by perforated paper rolls with other apparatus not so controlled, such as a kinematograph. The Figure shows a system in which a kinematograph projector controls the speed of an automatic musical instrument, which normally runs slightly faster than the kinematograph but is automatically braked at intervals so that its average speed is equalized with that of the kinematograph. The perforated roll p of the musical instrument is driven by a pneumatic or electric motor m, and has special perforations passing over holes in a tracker-bar f which are connected through pipes f with pneumatic relays s. These relays, which are constructed as shown in Fig. 4 of the parent Specification, comprise contacts in circuit with an electromagnet t, the armature of which carries a brake a adapted to act on a flywheel r which is driven by the motor m, as described in the parent Specification. A drum b, which is mounted on a shaft in or driven by the kinematograph, has an insulating segment b<1>; and three brushes a, respectively connected to a contact in each of the relays s, bear upon the drum. A source of current is connected on one hand to the drum and on the other to the magnet t. The arrangement is such that the circuit of the magnet t is closed, and the brake is thereby applied to the flywheel r, only when closure of contacts at any one of the relays s (occurring when a perforation in the roll p passes over the end of the corresponding pipe f<1>) takes place whilst the particular brush a connected to that relay is bearing on the metallic part of the drum. When the machines are in synchronism, the operation of a relay s occurs when the insulating segment b<1> is under the corresponding brush a, so that the magnet t is not then energized. The pneumatic relays s may be so constructed (as shown in Fig. 5 of the parent Specification) that they each comprise contacts which are normally closed and which are broken only when the pipes leading to them from the tracker-bar f are opened by the special perforations in the music roll p. In this case, the insulating segment of the drum b extends over two-thirds of the surface of the drum. The drum b may be rotated intermittently by ratchet mechanism instead of having a continuous rotary movement. The kinematograph may control the speed of several musical instruments or the like employing perforated rolls, by providing connections in parallel to the other controlled apparatus B, C, as shown in dotted lines. In a further alternative, the kinematograph may be the controlled apparatus, the system shown in the Figure being so modified that an electromagnetic brake is associated with the kinematograph, which in this case tends to run slightly faster than the apparatus having a perforated roll. Instead of using fixed brushes a, as shown, there may be provided brushes mounted on a disc upon the same axis as the drum band capable of being rotated, either in the same direction as or oppositely to the drum.