Abstract: A fused plug (12) of the add-on type includes a body shell (13') formed of integral one-piece molded construction. The shell has a recess (23) opening forwardly. A fuse site body (27) is receivable within the recess. The fuse site body includes longitudinal recesses (39, 39') at opposite sides for receiving blade plugs (20, 20') in mutually secured relationship. Fuse-receiving recesses (32, 32') are defined in the forward end of the fuse site body for receiving a pair of miniature cartridge fuses (33, 33') with one end of each of the fuses electrically contacting a respective blade plug. The fuse site body also provides for electrical connection of wire leads (36, 36') with opposite ends of the fuses, such leads extending through an opening in the shell. The fuse site body is provided with projections (29) which fit into apertures (30) on opposite walls of the body shell for locking the fuse site body within the body shell in mutually secured relationship.

Abstract: A fused plug constituting a safety lamp plug is provided for use with a light string set. A molded plastic body of the plug is formed of joined halves which define a first pair of compartments. Electrodes within such compartments define prongs extending from the body and blades within the body for receiving prongs of an add-on plug. Provided also within the molded body are a pair of compartments, each containing a safety lamp. Each safety lamp is a fuse lamp having a filament normally providing illumination but constituting a fusible element which melts upon current overload. The prong-defining electrodes are each interconnected with one lead of respective fuse lamp. The other lead of each fuse is interconnected with conductors for providing electrical power to the light string set. The fuse lamps are readily removable and illumination from them can be seen from outside the plug for determining their proper operation.

Abstract: A fused miniature light string set having a plurality of sockets receiving incandescent lamps, a plug at one end of string supplying power to the lamps and a receptacle at the other end for connecting another light string set to permit tandem stringing of sets. At least some of the sockets are adapted to receive shunt-type incandescent lamps having a shunt across the filament for permitting continued current flow if the filament burns out. All of the sockets are electrically connected in a series circuit by relatively fine gauge wire, other conductors being of a larger gauge. One end socket of this series has a terminal connected by one of the larger gauge wires to a plug terminal and by another such wire to a receptacle terminal. The other end socket similarly has one such wire connected to the other plug terminal and another such wire to the other receptacle terminal.