Patent GB-443070-A (GB)
Title: Improvements in or relating to synchronous-motor driven clocks
IPC: G04C21/08
Filed: 1935-06-13
Abstract: 443,070. Clocks. JUNGHANS AKT.- GES., GEB., Schramberg, W³rtemberg, Germany. June 13, 1935, No. 17061. Convention date, June 25, 1934. [Class 139] In a synchronous-motor clock the striking mechanism is driven directly from the motor through a coupling 2a, 6 and when the striking rack 13 reaches its position of rest at the end of the striking, the coupling is broken and the gathering wheel 11 is locked positively in a position in which the gathering pin 11<a> (or pins) on it is out of engagement with the rack teeth. A pinion 1, driven continuously by the synchronous motor, meshes with a pinion 2 which is loose on the hammer-pin shaft 3 so that it may be axially moved along shaft 3 whilst remaining always in mesh with pinion 1. Secured to shaft 3 are the pin-disc 7 for actuating the hammer and a wheel 6 which has radial slots 6a coacting with a pin 2<a> on pinion 2. Coacting with a hub on pinion 2 is a fork 4 fixed to a shaft 8 urged axially to the right, Fig. 3, by a spring 5. Wheel 6 meshes with a wheel 9 on a shaft 10 which carries the gathering wheel 11 with rack-gathering pin 11<a>. Shaft 10 also carries a laterally-flanged disc 12, the flange having a slot 12a which coacts with an arm 17. The clutch 2<a>, 6a is controlled by a rod 15, movable axially against a spring 16 and having an arm 18 which bears against the fork 4. Whilst the rod 15 is axially to the left, Fig. 3, arm 18 prevents the spring 5 from moving the parts 4, 2, 2a to the right. Carried on shaft 15 is an arm 15<a> having a lateral tailpiece 15<c> which moves in a hole in a movement plate so that it is movable only directly towards or away from the plate. The free end 15b of arm 15<a> rests upon a lever 19 which is pivoted at 19<a> and is pressed by spring 20 against a stop 19<b>. Arms 22b, 22<c> are rigid with one another and are pivoted at 26. Arm 22<c> coacts with a cam 21, rigid with the hour snail 14, and arm 22b carries a cam piece 22<a> which coacts with the arm 15<a>. A pin 22<d> on arm 22b lies in the fork of a bell-crank 23<a>, 23 pivoted at 27 whereof the arm 23 is adapted to block the right-hand end of shaft 8 (chaindotted position, Fig. 1). Action. At the striking time, cam 21 lifts the arm 22<c> and cam piece 22<a> on arm 22b displaces lever 15<a> and shaft 15 axially to the right, Fig. 3. At the same time, arm 23 is swung down to block the end of shaft 8. The end 15<b> of arm 15<a> is displaced from the plane of arm 19 and the latter rises and prevents the arm 15<a> from returning axially. The rack 13 is freed and moves down to the hour snail 14. When shaft 15 moved to the right, Fig. 3, its arm 17 left the slot 12<a> in disc 12 and arm 18 left the fork 4. When arm 22<c> drops off the rise of cam 21, arm 22b moves down and arm 23 moves left and frees the shaft 8, whereupon the spring 5 moves parts 4, 2, 2<a> to the right so that the pin 2a passes into one of the slots 6a of wheel 6 ; whereby the motor drives the trains 1, 2, 6, 3, 7 to actuate the striking hammer and 1, 2, 6, 9, 10, 11, 11<a> to raise the rack tooth-by-tooth as striking proceeds. When the rack 13 reaches its upper position of rest, a pin 13<a> on it coacts with a fixed lug 19<c> on the lever 19 to lower the working end of the latter and permit the arm 15<a> to return to its normal position. The shaft 15.is thus returned axially to the left, Fig. 3, by the spring 16, arm 18 moves fork 4 and wheel 2 to the left, compressing spring 5, and the coupling 2a, 6a is broken. At the same time the arm 17 enters the slot 12a in the flanged disc 12 and locks pin 11<a> in a position in which it is out of engagement with the teeth of rack 13.