Electric time-lag fuse having a small current rating

An electric fuse including

• a. a tubular casing of electric insulating material;
• b. a pair of terminal caps closing the ends of said casing;
• c. an elongated metal clad strip of insulating material wherein the metal layer is removed in the center of said strip and along the sides of said strip so that the metal remaining on said strip takes the form of two separate substantially I-shaped layers;
• d. a shorting strip of sheet metal conductively interconnecting the axially inner ends of said substantially I-shaped layers;
• e. a pair of soft solder joints effecting said conductive connection;
• f. a helical shorting strip-biasing-spring tending to dislodge said shorting strip to interrupt the circuit controlled by said fuse at two points thereof, said spring being normally shunted by one of said substantially I-shaped layers;
• and
• g. a pair of solder joints conductively connecting the inside of said terminal caps to the axially outer ends of said substantially I-shaped layers.

An electric time lag fuse including

• a. a substantially tubular casing of electric insulating material;
• b. a pair of terminal caps closing the ends of said casing;
• c. an elongated partially metal clad strip of electric insulating material inside said casing, said strip having a center area where the metal layer is entirely removed so as to form an insulating gap, the remaining metal clad areas including two relatively large areas, one to each side of said insulating gap, forming lag-blocks, two relatively large areas at the axially outer ends of said strip forming solder tabs, and two relatively narrow areas conductively interconnecting said lag-blocks and said solder tabs;
• d. a bridge conductively interconnecting said lag-blocks;
• e. a pair of soft solder joints conductively attaching said bridge to said lag-blocks;
• f. a helical bridge biasing spring tending to displace said bridge, said spring being normally shunted by one of said relatively narrow areas of said metal clad strip;
• and
• g. a pair of solder joints inside said casing conductively interconnecting said solder tabs and said terminal caps.