Abstract: A delay mechanism for retarding relative movement between two members has particular application in a hinge assembly for a dropout fuseholder. In one embodiment, a pin member rotatably connecting two adjacent members is disposed through a sleeve which has a cavity filled with viscous material, such as silicon putty. Protrusions extending from the shaft of the pin engage the putty and retard the relative rotational movement of the two members. In another embodiment, a friction member, such as a washer or annular seal, is disposed between the adjacent rotatable members. The friction member has facing surfaces contacting the opposing surfaces of the rotatable members such that the frictional forces between the friction member and the rotatable members retard rotation. In still another embodiment, the hinge assembly of a dropout fuseholder includes a latch member which rotates away from the fuseholder once dropout is initiated.

Abstract: A current responsive latching apparatus may be employed in a dropout fuseholder or other electrical component for retaining the component in a current-carrying position and disconnecting and isolating the electrical component upon the occurrence of an overcurrent of a predetermined magnitude. The apparatus includes a current path through the component, including a current-carrying stud or conductor, a portion of which extends outside the component for releasably engaging a support member. A latching apparatus, which may include an actuating member of memory allow or a bimetallic material, engages the conductor to retain the support member in a supporting position beneath the electrical component. The apparatus may further include a heater element in the current path to ensure that the actuation member is heated to the temperature necessary to cause it to change shape and release the conductor upon the presence of an overcurrent.

Abstract: A current-limiting dropout fuseholder includes multiple current paths through the fuse body. A primary current path includes a high current fusible element. A secondary current path in parallel with the primary path includes a triggering conductor that extends outside the fuse body and is connected to a moveable support. The second current path further includes a first spark gap for severing the triggering conductor upon the occurrence of a fault and the shifting of the fault current from the primary current path to the second current path. A second spark gap formed between the primary and the second current paths ensures that the fault current flows across the first spark gap for a time sufficient to sever the triggering conductor, thereby ensuring that dropout will occur.