Patent Publication Number: US-4320742-A

Title: Damper adjusting mechanism

Description:
BACKGROUND OF THE INVENTION 
     This invention generally relates to a damper control for stoves and particularly to such control for a fireplace installed woodburning tove. More particularly, this invention is directed to a damper control which includes a rod which adjusts the damper and a shield which prevents creosote build-up on the rod. 
     The prior art discloses mechanisms for adjusting the exhaust damper in woodburning stoves. These mechanisms are usually located above or on the upper side of the firebox and, in a fireplace installed stove, adjacent to the fireplace cover panel. The major disadvantage of this type of control is that, because of its position over the firebox, the operating mechanism for the damper becomes hot to the user&#39;s touch and its use requires reaching over the firebox. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the above-stated disadvantage of the prior art by locating the adjusting control on the front panel above the firebox door. An apparatus in accordance with the present invention employs a rod attached at one end to the damper and with the other end extended through the firebox wall opposite the fireplace cover panel. By moving this rod in either a first or second direction, the damper is opened and closed. The rod is held in the position commensurate with the desired damper opening by the use of multiple notches which engage the firebox wall. A shield is provided, within the firebox, to prevent creosote build-up in these notches. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings wherein like reference numerals refer to like elements in several FIGURES and in which: 
     FIG. 1 is a side view of a firebox with the upper portion of the side wall removed so as to expose a damper adjusting mechanism in accordance with a preferred embodiment of the invention; 
     FIG. 2 is a cross-sectional view of the damper adjusting mechanism taken through line 2--2 of FIG. 1; and 
     FIG. 3 is a cross-sectional view of the damper adjusting mechanism in FIG. 2 taken through line 3--3 of FIG. 1. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a firebox is indicated generally at 12. Within firebox 12 is a damper adjusting rod 16. The first end of adjusting rod 16 is attached to a damper 18. The second end of rod 16 extends through hole 24 of firebox front wall 26, wall 26 being located opposite a fireplace cover panel 28. The second end of the adjusting rod 16 is positioned just above firebox door 14. Attached to firebox wall 26, within the firebox 12 and surrounding adjusting rod 16, is a creosote shield 10. 
     Adjusting rod 16 may be moved in a first direction so as to extend a greater length of its second end through hole 24 of firebox wall 26. By moving adjusting rod 16 in a second direction the length of its second end through hole 24 of firebox wall 26 is reduced. The damper 18 is opened by moving adjusting rod 16 in the first direction and is closed by moving adjusting rod 16 in the second direction. Adjusting rod 16 is retained in different positions by means of notches 20 formed therein. The notches 20 have a width greater than the width of the firebox wall 26. By moving the adjusting rod 16 in either a first or second direction, through hole 24, and then by engaging the edge of firebox wall 26, formed by hole 24, into a selected notch 20 the adjusting rod 16 is retained in a desired position so as to retain damper 18 in a closed or open position. 
     The tubular creosote shield 10 is located within firebox 12 and welded to firebox front wall 26. The shield 10 is preferably coaxial with rod 16 and of rectangular shape with the planes running through the opposite corners of the rectangle being oriented in a crosswise configuration with one plane having a vertical orientation. Shield 10 has sufficient length and is positioned with respect to rod 16 so as to encompass that portion of rod 16 which is provided with notches 20. Shield 10 deters the build-up of creosote within the notches 20 and on the grooved portion of rod 16 whereby damper adjustment is not rendered increasingly difficult with continued stove use. 
     FIG. 2 is a cross-sectional view of FIG. 1 taken through line 2--2. FIG. 2 shows the above-mentioned configuration of the creosote shield 10 and its positioning so as to encompass the adjusting rod 16. FIG. 2 also shows the dimensions of notches 20 relative to rod 16. 
     With reference now to FIG. 3, a cross-sectional view of FIG. 2, through line 3--3, depicts the rod 16 within the creosote shield 10. 
     While a preferred embodiment has been illustrated and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it will be understood that the present invention has been described by way of illustration and not limitation.