Container bottom heater

Abstract

A bottom heater for use in assembling a container bottom and a sleeve includes a body having a peripheral wall and a heated air passage terminating in an outlet in the peripheral wall. A shape of at least a portion of the peripheral wall defining the outlet is such that heated air exiting the outlet is fluidly attached to an adjacent portion of the peripheral wall after exit because of the Coanda effect.

What is claimed is: 
     
         1 . A bottom heater for use with a container forming machine for assembling a container bottom to a sleeve, the bottom heater comprising:
 a circumferentially curved body having a peripheral wall terminating at an end wall; and   a heated air passage terminating in an outlet in the peripheral wall;   wherein a shape of at least a portion of the peripheral wall defining the outlet is curved axially along the body such that heated air exiting the outlet is fluidly attached to an adjacent portion of the peripheral wall after exit because of the Coanda effect.   
     
     
         2 . The bottom heater of  claim 1  wherein the outlet is continuous. 
     
     
         3 . The bottom heater of  claim 2  wherein the outlet extends entirely about a circumference of the body. 
     
     
         4 . The bottom heater of  claim 1  wherein the outlet separates the peripheral wall into first and second portions, and at least one of the first and second portions has a radius defining the shape of the at least a portion of the peripheral wall defining the outlet that is curved axially to control a direction of the Coanda effect. 
     
     
         5 . The bottom heater of  claim 1  wherein the Coanda effect is maintained for a predetermined distance along the peripheral wall. 
     
     
         6 . The bottom heater of  claim 5  wherein the predetermined distance corresponds to a functional heating area in an adjacent surface of a sleeve, a container bottom, or a combination of a sleeve and a container bottom. 
     
     
         7 . The bottom heater of  claim 6  wherein the functional heating area corresponds to a portion of the sleeve or the container bottom that overlaps with the other of the sleeve or the container bottom when the sleeve is folded inward to seal the container bottom with the sleeve. 
     
     
         8 . The bottom heater of  claim 1  wherein the heated air passage is defined by a first wall and a second wall and wherein the first wall, second wall, or both the first and second wall are provided at an angle with respect to an axis of the body. 
     
     
         9 . The bottom heater of  claim 1  wherein a proportion of the heated air attached to the adjacent portion of the peripheral wall because of the Coanda effect is varied to control an amount of heat provided to a container bottom disposed adjacent the bottom heater in use. 
     
     
         10 . The bottom heater of  claim 1  wherein the outlet comprises a plurality of discrete openings and wherein at least a portion of the peripheral wall defining the plurality of discrete openings is curved axially along the body such that at least a portion of the heated air exiting the plurality of discrete openings is fluidly attached to an adjacent portion of the peripheral wall after exit because of the Coanda effect. 
     
     
         11 . The bottom heater of  claim 10  wherein the plurality of discrete openings separates the peripheral wall into first and second portions, and at least one of the first and second portions for each of the plurality of discrete openings has a radius defining the shape of the at least a portion of the peripheral wall defining the plurality of discrete openings that is curved axially to control an amount and direction of the Coanda effect. 
     
     
         12 . The bottom heater of  claim 1  wherein at least one of a radius defining the curved portion of the outlet, a dimension of the heated air passage, an angle of at least one wall defining the air passage with respect to an axis of the body, or combinations thereof are configured to control an amount and direction of the Coanda effect. 
     
     
         13 . A bottom heater for use with a container forming machine for assembling a container bottom to a sleeve, the bottom heater comprising:
 a body having a peripheral wall terminating at an end wall; and   a heated air passage defined by at least a top wall and a bottom wall, wherein at least one of the top wall or the bottom wall leads into the peripheral wall along a curved surface to define a curved outlet;   wherein heated air flows through the curved outlet along the curved surface and along an adjacent portion of the peripheral wall for a predetermined distance due to the Coanda effect.   
     
     
         14 . The bottom heater of  claim 13  wherein the curved outlet extends entirely about a circumference of the body. 
     
     
         15 . The bottom heater of  claim 13  wherein the Coanda effect is maintained for a predetermined distance along the peripheral wall. 
     
     
         16 . The bottom heater of  claim 15  wherein the predetermined distance corresponds to a functional heating area in an adjacent surface of a sleeve, a container bottom, or a combination of a sleeve and a container bottom. 
     
     
         17 . The bottom heater of  claim 13  wherein at least one of the top wall, the bottom wall or both the top and bottom walls are provided at an angle with respect to an axis of the body. 
     
     
         18 . The bottom heater of  claim 13  wherein a proportion of the heated air attached to the adjacent portion of the peripheral wall because of the Coanda effect is varied to control an amount of heat provided to a container bottom disposed adjacent the bottom heater in use. 
     
     
         19 . The bottom heater of  claim 13  wherein the curved outlet comprises a plurality of discrete openings each defined by at least a top wall and a bottom wall, and wherein at least one of the top wall or the bottom wall for each of the plurality of discrete openings leads into the peripheral wall along a curved surface such that at least a portion of the heated air exiting the plurality of discrete openings is fluidly attached to an adjacent portion of the peripheral wall after exit because of the Coanda effect. 
     
     
         20 . The bottom heater of  claim 13  wherein at least one of a radius defining the curved surface of the curved outlet, a dimension of the heated air passage, an angle of at least one of the top wall or bottom wall defining the heated air passage with respect to an axis of the body, or combinations thereof are configured to control an amount and direction of the Coanda effect.