Embossing a flat metal blank (method, tool and object)

Abstract

Tool and method for embossing an artifact into a wall of a three-piece can, wherein a flat sheet or blank(s) of metal is transported along a transport bed ( 10 ) by several spaced apart groups of rollers ( 20, 22, 24 ), each having a top and a bottom roller. A rotating embossing roller pair ( 30 ) is provided between two of the groups of transport rollers, and driven by a servo drive ( 38 ). It embosses the artifact ( 11, 11′ ) into the flat, transported sheet or blank. The transport rollers, the embossing rollers and the sheet or blank have the same speed at the surface of the blank during embossing the artifact into the blank or sheet, and a length position of the artifact in the sheet or blank is determined, adjusted or corrected by a speed and position control ( 40 ) of the servo drive, driving the embossing roller pair ( 30 ) and shaping a cylindrical base shape of the can wall ( 15 ).

1 . Method of embossing an artifact ( 11 ,  11 ′) into a wall of a can, preferably an aerosol, paint or other three-piece can ( 10 ), wherein
 (a) a flat sheet or blank of metal (s) is transported (vs) along a transport bed ( 10 ) by several spaced apart groups of rollers ( 20 ,  22 ,  24 ), each having a top and a bottom roller ( 20   a ,  20   b , . . . ); 
 (b) a rotating embossing roller pair ( 30 ;  31   a;    31   b ), provided between two of the groups of transport rollers ( 22 ,  24 ), and driven by a servo drive or motor ( 38 ), embosses ( 32   a,    32   b ) the artifact ( 11 ,  11 ′) into the flat, transported sheet or blank (s); 
 (c) whereby the transport rollers at their surfaces, the embossing rollers at their surfaces, and the sheet or blank have the same speed (vs) during embossing the artifact ( 11 ,  11 ′) into the blank or sheet, and a length position (Yn, Yd of the artifact in the sheet or blank is determined, adjusted or corrected by a speed and position control ( 40 ) of the servo drive ( 38 ), driving the embossing roller pair ( 30 ); 
 (d) shaping ( 26 ) a cylindrical base shape (s*) of the can wall ( 15 ). 
 
     
     
         2 . Method of  claim 1 , wherein a front edge detector ( 50 ,  51 ), placed along a path of travel of the sheet or blank (s), provides the speed and position control ( 40 ) with a referential signal ( 55 ,  55   a ), representing a passing of the front edge (SI) and a remaining time interval (T1), until an embossing line or position ( 33 ) between the embossing rollers ( 30 ) is reached by the front edge (SI) of the sheet/blank. 
     
     
         3 . Method of  claim 2 , wherein the time interval (T1) is calculated using a distance (Y1) between a front edge detector nose ( 51 ) and the embossing position ( 33 ). 
     
     
         4 . Method of one of prior claims  claim 1 , wherein the speed and position control ( 40 ) adjust a circumferential position (X2) of an embossing feature pair ( 32   a ,  32   b ) in the embossing roller pair ( 30 ) during rotation, to match a target position ( 11   a , 11   a   1 ) on the sheet/blank (s), where (y 2 , y 11 , y 12 ) the embossing takes place and the artifact ( 11 ,  11 ′) is embossed. 
     
     
         5 . Method of  claim 1 , the sheet or blank having a printed surface and a target position where a printed artifact ( 11   a ,  11   a ′) is provided that is to be met by the embossed artifact ( 11 ,  11 ′). 
     
     
         6 . Method of  claim 4 , the target position as embossing field having distance (Y 11 ) from the front edge (S1). 
     
     
         7 . Method of  claim 4 , the control system ( 40 ) as speed and position control having at least one PI-controller ( 41 ,  42 ). 
     
     
         8 . Method of  claim 1 , the servo drive ( 38 ) being an AC-motor. 
     
     
         9 . Method of  claim 1 , the top and bottom embossing rollers ( 31   a,    31   b ) being rotatably linked by a gear-wheeled coupling ( 39 ). 
     
     
         10 . Apparatus for embossing an artifact ( 11 ,  11 ′) into a wall of a three-piece-can ( 15 ), the tool having
 (a) several groups of transport rollers ( 20 ,  22 ,  24 ), each having top and bottom roller; 
 (b) a rotatable embossing roller pair ( 3 D), having embossing features ( 32   a,    32   b ) at a certain position in their outer surface, and being mechanically coupled with a servo motor or drive ( 38 ); 
 (c) the embossing roller pair ( 3 D), and the servo ( 38 ) placed between the last ( 24 ) and the one prior to the last transport roller group ( 22 ), to act on flat blanks or sheets (s); 
 (d) a controller ( 40 ) for controlling the servo ( 38 ) and receiving a referential signal ( 55 , 55   a ), indicative of a front edge (SI), each of the flat blank/sheet passing a sheet detector ( 50 ) with a feeding speed (vs), implied to the blank/sheet by the transport rollers ( 20 ,  22 ,  24 ). 
 
     
     
         11 . Apparatus of  claim 10 , a speed coupling (as rotational speed) of the transport rollers ( 20 ,  22 ,  24 ) are provided by a mechanical link, such as gear wheels, belt, toothed belt, and a corresponding speed coupling to the embossing rollers ( 30 ) is done by control ( 40 ) and implied by the servo drive or motor ( 38 ). 
     
     
         12 . Apparatus of  claim 11 , a speed of the embossing rollers ( 30 ) is allowed or even forced to change as compared to the transport rollers ( 20 ,  22 ,  24 )′ to adjust for positional deviations (y 2 , x 2 ), preferably the controller ( 40 ;  41 , 42 ) comprising at least a speed controller ( 41 ). 
     
     
         13 . Apparatus of  claim 11 , a diameter of each embossing roller ( 30 ) being larger than a diameter of each transport roller ( 20 ,  22 ,  24 ). 
     
     
         14 . Apparatus of  claim 10 , a distance of the sheet detector ( 50 ,  51 ) from the first transport roller group ( 20 ) being less than 10 cm, preferably less than 5 cm or less than about 2.5 cm. 
     
     
         15 . Apparatus of  claim 10 , the embossing roller pair ( 30 ) is linked or connected by a gear-wheeled system ( 39 ). 
     
     
         16 . Metal can having a cylindrical body and a height, larger than a diameter thereof, and having a body wall ( 15 ), manufactured according to  claim 1 . 
     
     
         17 . Metal can of  claim 16 , being an aerosol can having an axially extending weld/seam joining free edges of the cylindrically pre-shaped wall ( 15 ), to form the body of the aerosol can. 
     
     
         18 . Metal can of  claim 16 , being a three-piece can, with top end, cylindrical wall and bottom end. 
     
     
         19 . Apparatus for embossing an artifact ( 11 ,  11 ′) into a wall of a three-piece-can ( 15 ), the tool having
 (a) several pairs of transport rollers ( 20 ,  22 ,  24 ), each having top and bottom roller; 
 (b) a rotatable embossing roller pair ( 30 ), each roller having an embossing feature ( 32   a , 32   b ) at a certain position in an outer surface thereof, and being mechanically coupled to synchronize the embossing features upon rotation with a servo drive ( 38 ); 
 (c) the embossing roller pair ( 30 ), and the servo ( 38 ) being placed between the last ( 24 ) and the one prior to the last transport roller pair ( 22 ), to act by embossing flat blanks or sheets (s); 
 (d) a controller ( 40 ) for controlling the servo ( 38 ) to adjust the embossing features ( 32   a ,  32   b ) onto a certain, given position on each blank/sheet having a feeding speed (vs), implied to each blank/sheet by at least some of the transport rollers ( 20 ,  22 ,  24 ). 
 
     
     
         20 . Apparatus of  claim 19 , the embossing features ( 32   a,    32   b ) being complementary.