Patent GB-362848-A (GB)
Title: Improvements in or relating to electrical time transmitters
IPC: G04C3/02
Filed: 1930-09-02
Abstract: 362,848. Electric clocks. JONES, F. HOPE-, 32, Clerkenwell Road, London. Sept. 2, 1930, No. 26170. [Class 139.] A pendulum clock of the type wherein a count wheel is .gathered one tooth at each double swing of the pendulum and releases every half-minute a gravity arm which thereupon gives a direct impulse to the pendulum, is characterized by a permanent magnet M which is attached to the pendulum P and passes close to an armature B which is thereby moved to close contacts. Magnet and armature may be reversely mounted. The movement of the armature may rock a mercury switch. Pendulum P, Fig. 1, beats half-seconds and has a bracket J which receives the half-minute impulse from gravity lever G. At each swing magnet M attracts armatures B, B<1> to close contacts C, C<2> and C<1>, C3. The gravity arm G has a finger coacting with steps L, L<1> on a catch K controlled by spring Q. The latter is rigid with the armature A<2> of a magnet H and tends to move upwards vertically. A tongue Q<1> on spring Q coacts with a stop P<3> so that when spring W moves armature A<2> to the left, spring Q is forced down by pin P<3> and latches under shoulder L2. D is a polarized dial movement with two independent magnets E, El which are energized by contacts C, C<2> and C<1>, C<3> to actuate pawl mechanism A<3>, N<2> for advancing the ratchet wheel N<1>. This wheel rotates once every half-minute, a pin P<2> on it closing contacts S, S<1>. Gravity lever G is raised, after giving its impulse to the pendulum, by armature A<1> of magnet T in the known manner. Specifications 6066/05 and 1945/07, [both in Class 139, Watches &c.], are referred to. Assuming that pendulum P has passed through zero, moving to the right, and is just about to complete the 29th second, magnet M closes contacts C<1>, C<3> to energize magnet E, advancing wheel N<1> one tooth and completing the 29th second. This closes contacts S, S<1>. Returning to the left, the pendulum again closes C<1>, C3 but this merely re-energizes magnet E without effect on the ratchet. C, C<2> are then closed to energize magnet E<1>; this removes pawl N<2> to the next tooth. Closure of contacts S, S<1> energizes magnet H whereby armature A<2> and spring Q move catch K to the right so that the finger of gravity lever 6 falls on to the next step L<1> of the catch. Spring Q returns to the left and moves upwards on to a second shoulder L3. At the next swing of the pendulum to the right contacts C, C<2> close and, through circuit a<5>, S, S<1>, again energize magnet H to move spring Q to the right. Lever G moves off step Ll and gives a direct impulse to the pendulum. When magnet H is de-energized spring W forces tongue Q<1> under pin P<3> so that the tongue and spring move down and re-engage shoulder L<2>, lever G being replaced on step L by parts T, A<1>. Continuing its movement to the right pendulum P and magnet M close contacts C<1>, C3 to energize magnet E and advance wheel N<1>, thus opening contacts S, S<1>. When the pendulum stops in its zero position, magnet M is midway between armatures B, B<1> so that C, C<2> and C<1>, C<3> are all open. In another form, Fig. 2, the pendulum P beats seconds and only one armature, B, is used ; wheel N<1> has sixty teeth and two pins P<2>, P<4>, and its arbor carries a seconds hand which operates over an inset circle in the clock dial or as a centre-seconds hand which actuates concentric hour and minute hands. Once each halfminute contacts S, S<1> are closed and with contacts C<2> complete the circuit for magnet H, armature K of which releases the gravity lever G. In order that the magnet H may only be energized by closure of contacts C<2> as the pendulum swings to the right, Fig. 2, a blade P<6> on the pendulum coacts with a pin P<5> on the gravity arm as the pendulum swings to the left. This is in case the device gets out of phase by one step. Various suitable constructions for the contact C<2> and armature B are shown. Synchronizing.-Secondary dials may be inserted in the line b<8>, Fig. 2. A switch is at N for the normal working described above, at R for retarding all the secondaries, and at A for accelerating all the secondaries. Specification 5687/09, [Class 139, Watches &c.], also is referred to.