Abstract:
The invention provides a fuel saving device comprising a flue damper of simple mechanical construction mounted on a support member. A hinge connects the flue damper to the support member allowing the closure of the flue damper which is counter balanced when the furnace is shut down. When the furnace is on the gas flow opens the damper.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to dampers for use with a furnace and more particularly to a fuel saving damper which operates in association with the operation of a furnace and flow of gases therefrom. 
     Flue dampers are used as shown in U.S. Pat. No. 4,108,369 granted Aug. 22, 1978 Re. 31,112 granted Dec. 28, 1982 to John Prikkel, III. This damper requires complicated electrical circuitry and complex mechanical mechanisms for operation. Additionally other flue damper devices are of complex design and expensive to produce. Furthermore, complex mechanisms deter system reliability and create an increased probability for breakdown and excessive maintenance. U.S. Pat. No. 4,372,485 granted Dec. 1, 1980 to Frances J. McCabe is another example of a complex flue damper systems, as is U.S. Pat. No. 4,477,248 granted Aug. 4, 1983 to Robert R. Dulac. These systems and others are costly to make, install and maintain. 
     Therefore a need exists for a simple mechanical fuel saving device which is low cost to manufacture, install and maintain. 
     SUMMARY OF THE INVENTION 
     It is a principle object of this invention to provide a new and improved damper. 
     It is another object of this invention to provide a new and improved fuel saving device. 
     It is yet another object of this invention to provide a new and improved simple mechanical fuel saving device. 
     It is still another object of this invention to provide a new and improved mechanical fuel saving device activated by furnace gases. 
     Further objects of the invention will appear as the description proceeds. 
     To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only and that changes may be made in the specific construction illustrated and described within the scope of the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     The figures in the drawings are briefly described as follows: 
     FIG. 1 is a side edge elevational view of the invention shown installed in a flue pipe of an oil burner. 
     FIG. 2 is an enlarged plan view of the invention per se. 
     FIG. 3 is a perspective view of the invention&#39;s components shown disassembled from each other. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIGS. 1 and 2 there is generally shown a fuel saving device 10. Fuel saving device 10 is positioned at the top end of a plenum 12 leading directly to a furnace. 
     Fuel saving device 10 is disposed in a plane perpendicular to plenum 12 mounted to an auxiliary plenum 16. Attachment of fuel saving device 10 in auxiliary plenum 16 is such that device 10 is disposed at a bottom portion 14 of auxiliary plenum 16 and device 10 being disposed in a plane parallel to line of symmetry X--X of auxiliary plenum 16 (FIG. 1). A support member 20 of device 10 is secured to bottom portion 18 which has a hole 22 essentially centrally located along line of symmetry Y--Y (FIG. 2) and at a predetermined distance from a lip 24 of support member 20. Lip 24 is disposed at one end of support member 20 in a plane perpendicular to auxiliary plenum 16 and extending over the edge of bottom portion 18 of plenum 16 and coacting with an edge 25 of bottom portion 18 of plenum 16. Attachment of support member 20 and bottom portion 18 is achieved in a conventional manner by disposition of a sheet metal screw, pop rivet, nut and bolt or the like through hole 22. Disposed at a second end 26 of support member 20 is a pair of rod support 28 and a damper stop 30 formed as an integral part of support plate 20. Rod supports 28 are formed back from edge 26 essentially 180° in a conventional manner over a die, not shown, to form a pair of rod support holes 32 with an axis Z--Z essentially perpendicular to line of symmetry Y--Y of support member 20, damper stop 30 being disposed in a plane essentially parallel to lip 24. 
     A rectangular opening 34 of a predetermined size is disposed proximate to edge 26 and essentially central to axis Y--Y. A pair of slots 36 are radially cut into support plate 20 (FIG. 3) at a size equal to approximately half the length of edge 26 the radial distance being taken from the center of side 26. A first portion 38 of support member 20 (FIGS. 2 and 3) is thus formed as a flat truncated half circle. A second portion 40 of support member 20 is formed cylindrically as is lip 24. A damper plate 42 as shown in FIGS. 1, 2 and 3 is a flat circular plate of essentially the same radial dimensions of first portion 38 of support 20, with a breather hole 44 proximate to line of symmetry Z--Z and disposed on a first portion 46 of damper 42, which has a counter balance 48 comprised of a sheet metal screw and washer nut and bolt or the like. The aforementioned counter balance proximate the radial periphery along axis Y--Y. A second portion 50 of damper 42 is a half circle. Damper 42 has a set of hinges 52 located along axis Z--Z and equidistant from the center of damper 42. A set of hinge openings 54 essentially the same diametral size as rod support holes 32 are formed by hinges 52. A rod 56 essentially is the same length as the diameter of damper plate 42 and has a diameter less than the size of rod support holes 32 and hinge opening 54. Assembly of damper plate 42 and support member 20 is executed by passing rod 56 through rod support holes 32 and hinge openings 54 after which rod supports 28 are crimped at their furthest radial point. 
     In actual operation when the furnace ignites the build up of hot gases immediately force the damper plate 42 to rotate to a vertical position there by allowing the hot gases to pass relative unimpeded. But it is when the furnace extinguishes that the device really saves fuel. This is because the pressure of the exiting gases drop rapidly and thus the device quickly rotates to a horizontal position shutting off the flow of hot exiting gases and trapping the remaining hot gases in the furnace which would other wise escape and then require additional fuel to reheat the furnace which would be partially cooled by the entering of cold ambient air. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing from the spirit of the invention.