Patent GB-888232-A (GB)
Title: Improvements in and relating to electric cutout switches
IPC: H01H71/46
Filed: 1959-09-28
Abstract: 888,232. Electrically tripped switches; electromagrietic switches. KABUSHIKI KAISHA NIHON DORYOKU ANZENKI SEISAKUSHO. Sept. 28, 1959 [Sept. 29, 1958], No. 32928/59. Class 38 (5). A fuseless cut-out switch suitable for controlling an electric motor has an electromagnetic overload trip restrained from operating during the motor starting period. The switch comprises a pair of plates 7, 7<SP>1</SP> mounted on an insulating base 1 and carrying a spindle 17 attached to a main lever 25 and to a pair of links 29, 29<SP>1</SP>, the spindle 17 also serving as a pivot for the ends 20, 20<SP>1</SP> of a hollow auxiliary lever 19 which can fit round the lever 25 to facilitate simultaneous operation. The plates 7, 7<SP>1</SP> also carry a bracket 8 supporting a coil 12, and a pin 16 to which is pivoted an armature 15 biased upwardly by the U-shaped end 24 of a spring 22 carried by the pin 16, the spring arms 23, 231 engaging grooved rollers 21, 21<SP>1</SP> carried by the ends 20, 20<SP>1</SP>, so that clockwise rotation of the lever 19 increases the bias of spring 22. A pin 30 forms a common pivot for the lower ends of links 29, 29<SP>1</SP>, the upper ends of a channel-shaped link 31 and a catch 32 which is engageable by the lever 25 and engageable with the upper edge of the base of a channel-shaped link 34, the latter, together with the lower ends of the link 31, being pivoted to a pin 33 carrying a spring which maintains the bases of the links 31, 34 in contact. The lower ends of the link 34 are pivoted to a pin 38 carried by the sides 37, 37<SP>1</SP> of a channel-shaped element 36, these sides being pivoted to the plates 7, 7<SP>1</SP> by a pin 35. A spring 43 biases element 36 anti-clockwise to raise moving contacts 41, 41<SP>1</SP> carried by a channel-shaped element 39, which is pivoted to the pin 38 and spaced from the element 36 by a spring 42. A rocker 45 biased anticlockwise by a spring 47 is pivoted by a pin 44 to the plates 7, 7<SP>1</SP> and is engageable by a plate 46 carried by the armature 15 to rotate the catch 32. To close, levers 19, 25 are rotated clockwise, together from their common position adjacent the armature 15, so that the links 31, 34 tend to move into line to depress the element 36 and contacts 41, 41<SP>1</SP> which are latched in this position by the engagement of members 32, 34, and so that the spring ends 23, 23<SP>1</SP> are depressed to prevent operation of the armature 15 by the motor starting current, Fig. 7 (not shown). When the current has stabilized, the lever 19 is restored to normal, Fig. 5, so that any subsequent overload can attract the armature 15 to release the catch 32 through members 45, 46 and allow contacts 41, 41<SP>1</SP> to be opened by the spring 43. The coil 12 has a second arcuateshaped armature 48 mounted on a resilient strip 50 actuating a pair of contact strips vertically mounted on the base 1, Fig. 3 (not shown), so that during the starting period a circuit through a lamp 54 and resistor 53 is closed, to indicate the presence of surge current. The rollers 21, 21<SP>1</SP> may be replaced by apertured outwardly directed lugs.