Electric heating device for heating the flow of glue to a labeling machine

Apparatus for heating cold glue for use in labelling machines and the like, comprising:

• a pair of thin metal planar members spaced apart and in parallelism with each other, said members being joined to each other at their edges to thereby define a conduit for fluid glue between the interior surfaces of the members,
• holes in a planar member and tubular elements respectively fastened to said member coincident with the holes to provide an inlet and an outlet for glue to flow through the conduit,
• a pair of generally planar electric heating elements respectively interfaced with the surfaces of the planar members exterior to the conduit, said heating elements making contact with a major portion of the area of the exterior surfaces,
• a pair of support plates arranged in parallelism with each other and respectively in interfacing relation with said planar heating elements, the opposite margins of said plates extending beyond the margins of said conduit and said heating elements,
• spacer block means, respectively, interposed between corresponding margins of said plates and means for clamping said plates to said spacer block means to secure said heating elements and conduit between them such that the support plates, the spacer block means, the heating elements and the conduit are composed as a unit for being supported on said spacer blocks,
• a housing for said unit having opposed walls which define a cavity into which said unit fits with substantial air space around most of the unit for inhibiting heat transfer through the housing.