Heating Fan

Abstract

A heating fan has a fastening means for fastening of said fan to a first surface. A stem connects the fastening means to a hub. The hub has a motor unit. The motor unit rotates a plurality of wings extending radially from said hub. The wings have upper and lower surfaces. Each wing has a leading edge and a trailing edge, defining upper and lower surfaces therebetween. At least one wing has electrical heating means integrated or connected to the upper surface. At least more than half the length of the leading and/or trailing edge is bent downwards relative to the surface of the wing.

1 . Heating fan, where said fan comprises fastening means for fastening of said fan to a first surface, a stem connecting the fastening means to a hub, where said hub comprises a motor unit, where said motor unit rotates a plurality of wings extending radially from said hub, such that the wings have an upper and a lower surface, wherein each wing has a leading and trailing edge, defining upper and lower surfaces there between where at least one wing has electrical heating means integrated or connected to said upper surface, where at least more than half the length of the leading and/or trailing edge is bent relative to the surface of the wing. 
     
     
         2 . Heating fan according to  claim 1  wherein the wing profile in a cross section perpendicular to the radial extent of the wing relative to the hub, comprises three distinct substantially linear sections, a first linear section extending between 5 to 25 mm from the leading edge and a second linear section extending between 5 to 25 mm from the trailing edge, and a third linear section arranged between the first and second sections, where said third linear section has an extent between 35 and 110 mm, where the first and second linear sections are angled 5° to 60° relative to the third section. 
     
     
         3 . Heating fan according to  claim 1  wherein the heating means is provided by metal leads having an Ohm-resistance of approximately 40 Ω or more, where said metal leads are embedded in a thick heat distributing film layer preferably a dielectric composition having a layer thickness of 50 micrometers or more. 
     
     
         4 . Heating fan according to  claim 3  wherein the heating means is selected from the group of materials having positive temperature coefficient. 
     
     
         5 . Heating fan according to  claim 1  wherein the hub comprises a collector which collector transfers electrical power from the stem/hub to at least one heating element arranged on at least one of the plurality of wings, where said collector comprises a central non-conductive member, where at least a first and a second conductive member is arranged about said central non-conductive member, where non-conductive means are arranged between said first and second conductive members, and where first and second blade means are arranged for conductive contact with first and second conductive members respectively, and where said first and second blade means comprises means for a conductive connection to the heating means arranged on the wings. 
     
     
         6 . Heating fan according to  claim 5  wherein the first and second conductive members are ring shaped, having a conductive surface in the radial direction, and where the first and second blade means are biased towards contact with the conductive surfaces of the first and second conductive members respectively. 
     
     
         7 . Heating fan according to  claim 1  wherein the hub comprises a collector which collector transfers electrical power from the stem/hub to the at least one heating element arranged on at least one of the plurality of wings, where said collector comprises a central non-conductive member, n conductive members are arranged about said central non-conductive member, where non-conductive means are arranged between said n conductive members, and where n conductive blade means are arranged for conductive contact with the n conductive members, such that one conductive member is in conductive contact with one conductive blade member, and where said blade means comprises means for a conductive connection to the heating means arranged on the wings, where n is a number between 2 and 9, preferably 3. 
     
     
         8 . Heating fan according to  claim 5  wherein the central non conductive member is symmetrical about a central axis, and that the non conductive means are integral with the central member, and furthermore that electrical leads may be arranged in the central non conductive member, and brought into electrical contact with the conductive members. 
     
     
         9 . Heating fan according to  claim 1  wherein further means for increasing the roughness of the blades' surface, thereby creating more turbulence, is provided on the blades' surface. 
     
     
         10 . Blade for use in a heating fan according to  claim 1  wherein the blade has a front and rear face, two side edges, an inner edge and an outer edge, where the inner edge is suitable to be mounted to a hub of a fan, where the blade is made from a ferrite material, and that an electrical conductive resistive lead is arranged on the front face, said lead having electrical connection means, and that furthermore a dielectric layer of at least 50 micrometers is arranged on said front face covering a substantial part of said front face, and that along the side edges the faces are bent out of the general plane of the faces.