GB1026303A - Improvements in or relating to electrical striking mechanisms for clocks - Google Patents

Abstract

1,026,303. Clocks. TELEFONBAU UND NORMALZEIT G.m.b.H. June 21, 1963 [June 22, 1962], No. 24686/63. Heading G3T. The striking mechanism comprises a rack 15 movable into sensing engagement with an hour disc 14 stepped in accordance with the tooth spacing of the rack. The rack is stepped back into the initial position shown, on each stroke through an electromagnet 26 operating a pawl 31. A detent pawl 17 holds the rack at each step. This pawl has an arm 19 which extends into the path of movement of a detent 20 on a lever 22 carrying a gong clapper 29 and controlled by an armature 25 of the magnet 26. The detent 20 is so arranged that during the first stroke of the clapper, which releases pawl 31, the pawl 17 is also held disengaged from the rack which moves to engage disc 14. A wheel 11, meshing with relatively great tooth play with a wheel of the time train, makes one revolution per hour. Fast with wheel 11 are a lug 12 actuating a contact 32, and an armature rotatable between poles of an electromagnet 35. When contact 32 closes, magnet 26 is energized and armature 25 actuates, through a contact abutment 24, the clapper arm 22. The contact at 24 is thus broken and arm 22 closes a contact 37 to energize magnet 35. The tooth play of wheel 11 allows armature 34 to be pulled into line with the poles whereby contact 32 is broken and solenoid 26 deenergized. Arm 22 returns against an air dashpot 27. The circuit for magnet 35 is completed through a changeover switch 18 operated by the racks 15 so that this circuit is broken as soon as the rack leaves its initial position. When successive strokes of the hour are to be sounded, rack 15 moves through more than one tooth space so that on the first return movement of arm 22, a contact 18 I of the changeover switch is closed. Thus, through contact piece 24, a circuit is again immediately produced for solenoid 26 operating lever 22. This action takes place until rack 15 has returned to initial position wherein contact 18 I is broken and contact 18 II is made. A second striking mechanism 41-45 produces half-hourly strokes. In another embodiment, rack 15 is arcuate and switching lug 12 is moved mechanically to release contact 32 by a member moved by means connected with the arm 22.