Aquarium heater

Claim 1

An aquarium heater comprising a hollow glass housing provided with a closed end, an electric heating element, means for controlling passage of electrical energy to said heating element, means for supporting said heating element in said housing in a general helical configuration with said heating element in spaced relation with said housing, said supporting means comprising a elongate flat member of electrically insulative material having two longitudinally extending opposite edges, said elongate member including a plurality of longitudinally spaced transverse limbs extending from each of said opposite edges with said transverse limbs of one of said opposite edges being co-extensive with associated transverse limbs of the other opposite edge to define a plurality of longitudinally spaced slots at each of said opposite edges, said heating element being helically wound on said elongate member with turns thereof seated in said slots and having a maximum diametral extent substantially less than extent of said transverse limbs and being so wound on said elongate member in such manner as to remain entirely laterally inwardly of said slots with there being one of said heating element turns for each of said slots, said elongate member including a pair of longitudinally spaced opposite end portions, said heating element including mutually crossing helical portions having respective end terminals terminating proximate one another mutually at one of said end portions of the elongate member, said mutually crossing helical portions extending in a common direction and being free from contact with one another, said transverse limbs being seated in contact with interior of said housing to provide a flush relation for maintaining said heating element in a fixed lateral position so that said heating element is maintained in a laterally spaced relation with said interior of said housing, and said elongate member including a longitudinally extending limb engaging said closed end of said housing for maintaining said heating element and said housing in longitudinally spaced relation.