Deep drawn candle can with formed safety bottom

Abstract

A seamless candle can is formed in a blank and draw operation, and includes a complex bottom structure formed at the end of the drawing process. The bottom structure includes an annular base which occupies less than 30% of the area of the bottom surface, and a raised central platform for supporting a wick structure. The platform is raised at least 0.25 inch above the container bottom. A gently sloping surface joins the annular support ring to the central platform. The distance by which the platform is raised and the angle of the connecting surface are adapted to prevent overstretching of the material during the formation of the bottom, so as to prevent the formation of holes in the seamless can which would cause leaks. The central platform serves to support a wick sustainer at a location above the bottom of the can in order to reduce the possibility of flash-over.

What is claimed is:  
     
         1 . A candle can deep drawn from a circular metal blank, the candle can comprising; 
 a drawn cylindrical sidewall connecting a closed bottom to an open top,    the closed bottom including a peripheral annular ring and a central cone shaped dome, the annular ring merging into the cylindrical wall,    the central cone shape dome having an angled bottom wall surface and a mounting surface at the apex of the dome, the mounting surface raised at least {fraction (3/16)} inches above the annular ring to provide a seat for a wick sustainer,    the angled bottom wall surface joining the mounting surface to the annular ring and disposed at an acute angle to a plane through the annular ring in the range between 15 and 60 degrees,    whereby, when the can bottom is seated on a supporting surface, the majority of the bottom is spaced therefrom.    
     
     
         2 . The candle can of    claim 1    in which the mounting surface of the central cone shaped dome includes a substantially planar central floor in a plane generally parallel to the plane through the annular ring, and an upstanding cylindrical rim surrounding the floor to create a dish indentation sized to closely fit about and thereby position a wick sustainer.  
     
     
         3 . The candle can of    claim 1    in which the mounting surface of the central cone shaped dome comprises a flat plateau in a plane generally parallel to the plane through the annular ring.  
     
     
         4 . The candle can of    claim 1    in which the open top is provided with a curled peripheral edge, and the angled bottom wall joins the annular ring in a configuration including a gripping discontinuity for supporting the sidewall during the formation of the curl.  
     
     
         5 . The candle can of    claim 4    in which the mounting surface of the central cone shaped dome includes a substantially planar central floor in a plane generally parallel to the plane through the annular ring, and an upstanding cylindrical rim surrounding the floor to create a dish indentation sized to closely fit about and thereby position the wick sustainer.  
     
     
         6 . The candle can of    claim 4    in which the mounting surface of the central cone shaped dome comprises a flat plateau in a plane generally parallel to the plane through the annular ring.  
     
     
         7 . The candle can of    claim 5    including a dimple in the center of the central floor sized to accommodate a wick protruding from the base of the sustainer.  
     
     
         8 . The candle can of    claim 6    including a dimple in the center of the central floor sized to accommodate a wick protruding from the base of the sustainer.  
     
     
         9 . The candle can of    claim 5    in which the gripping discontinuity includes a sharply bent but only slightly displaced annular notch defining a gripping surface near the bottom of the cylindrical wall for providing restraining support to the wall to resist the force imposed at the top of the wall when forming the top curl.  
     
     
         10 . The candle can of    claim 6    in which the gripping discontinuity includes a sharply bent but only slightly displaced annular notch defining a gripping surface near the bottom of the cylindrical wall for providing restraining support to the wall to resist the force imposed at the top of the wall when forming the top curl.  
     
     
         11 . A method of forming a candle can including the steps of: 
 deep drawing a cylindrical blank to produce a can having an upstanding cylindrical wall having a height which is at least 50% of the diameter of the cylinder;    near the end of the deep drawing operation stamping a complex shape in the center of the blank to form a can bottom, the complex shape including;    a peripheral annular ring forming the base of the bottom and occupying no more than about 30% of the cylinder diameter, and    a central cone shaped dome having an angled bottom wall surface and a mounting surface, the mounting surface raised from the bottom by at least {fraction (3/16)} inches to form a seat for locating and supporting a wick sustainer, the angled bottom wall joining the mounting surface to the peripheral annular ring,    forming the angle of the cone shaped dome bottom wall with respect to a plane through the annular ring sufficiently shallow to allow formation of the peripheral annular ring and the central dome without puncture of the bottom surface during the metal stretching occasioned during stamping of the bottom configuration.    
     
     
         12 . The method of    claim 11    further including the step of trimming the raw edge of the drawn container, and forming a moderate inward curl of the edge during the trimming operation.  
     
     
         13 . The method of    claim 12    in which the step of stamping a complex shape includes forming a discontinuity in the bottom near the peripheral ring, 
 and wherein the method further includes the step of forming a curl in the trimmed edge of the container, the step of forming the curl including supporting the cylindrical wall and gripping the discontinuity to resist force applied during the curl forming operation.  
 
     
     
         14 . A method of forming a seamless candle can comprising the steps of forming a metal blank, deep drawing the metal blank to form a wall structure having a raw edge, and at the end of the drawing operation shaping the metal at the center of the blank to form a complex bottom in which only a minor portion of the blank is left in a plane defined by an annular base ring, and the majority of the blank is deflected upwardly into the drawn wall structure to form a central cone shaped dome having a mounting surface spaced by at least {fraction (3/16)} inches above said plane, and a gently sloping cone surface joining the mounting surface of the dome to the annular base ring, whereby the annular base ring provides support to the can when placed on a flat surface, and the gently sloped angled cone surface allows raising of the mounting surface without overstretching the metal to avoid perforating the metal and thus creating leaks in the seamless can.  
     
     
         15 . The method of    claim 14    further including the step of trimming the raw edge of the drawn container, and forming a moderate inward curl of the trimmed edge during the trimming operation.  
     
     
         16 . The method of    claim 15    in which the step of shaping the metal at the center of the blank includes forming a discontinuity in the can bottom near the annular base ring, 
 and wherein the method further includes the step of forming a curl in the trimmed edge of the container, the step of forming the curl including supporting the wall structure and gripping the discontinuity to resist force applied during the curl forming operation.  
 
     
     
         17 . A unitary metal candle can structure of the type normally filled with an ignitable fuel, said candle can composed of: 
 a continuous vertically deep drawn sidewall that transitions through a stamped formed curved can wall region and into a stamped can base that includes an internal upwardly directed cone shaped dome having a mounting surface upon which a candle wick carrying element maybe securely located in an apex region of the cone shaped dome.    
     
     
         18 . The unitary metal can structure of    claim 17    wherein the curved transition can wall region creates an annular support surface for the candle can base to thereby simultaneously establish annular internal volume of fuel separated by the cone shaped dome from a candle wick flame near the end of both the candle wick life and the supply of fuel which thereby minimizes flash-over while also creating an annular supporting surface for the candle can base to thereby reduce heat transfer from the candle fuel to a support surface.