Apparatus for ascertaining the transverse dimensions of rod-shaped articles

Abstract

The invention relates to an apparatus which embodies an optical measuring assembly serving to ascertain the transverse dimensions (such as diameters) of at least substantially cylindrical rod-shaped articles, preferably cigarettes or other rod-shaped articles of the tobacco processing industry, and includes a radiation source employing at least one first preferably circular array of light emitting diodes or the like, an evaluating unit employing at least one preferably circular array of signal generating charge coupled devices or the like, and a control unit which regulates the operation of batches of neighboring diodes and receives preferably short-lasting signals from the charge coupled devices located in the shadow produced by the article which is coaxial with and is spacedly surrounded by the two arrays. The article can be stationary or it can move (such as axially) relative to the coaxial arrays.

What is claimed is:  
     
         1 . Apparatus for ascertaining transverse dimensions of at least one at least substantially rod-shaped article, including an optical measuring assembly comprising: 
 a radiation source arranged to direct radiation against an article so that the article intercepts a portion of radiation which is indicative of the transverse dimension thereof, said source comprising at least, one first array of radiation emitting first elements; and    an evaluating unit including at least one second array of radiation-sensitive second elements located at least substantially opposite said radiation emitting first elements and in the path of propagation of radiation from said source toward the article to generate signals denoting the amount of radiation being intercepted by the article.    
     
     
         2 . The apparatus of  claim 1 , wherein said first elements include light emitting diodes.  
     
     
         3 . The apparatus of  claim 1 , wherein said second elements include charge coupled devices.  
     
     
         4 . The apparatus of  claim 1 , wherein the article constitutes at least a portion of a rod-shaped smokers' product.  
     
     
         5 . The apparatus of  claim 1 , wherein said evaluating unit is arranged to effect a short-lasting determination of the transverse dimension of the at least one rod-shaped article in said path.  
     
     
         6 . The apparatus of  claim 1 , wherein the article in said path is stationary.  
     
     
         7 . The apparatus of  claim 1 , further comprising means for advancing the at least one article across said path.  
     
     
         8 . The apparatus of  claim 1 , wherein at least one of said first and second arrays at least partially surrounds the article in said path.  
     
     
         9 . The apparatus of  claim 1 , wherein at least one of said arrays has an arcuate shape.  
     
     
         10 . The apparatus of  claim 9 , wherein said at least one array forms at least a portion of a circle having a center and the article in said path is located at least close to said center.  
     
     
         11 . The apparatus of  claim 10 , wherein at least one of said arrays forms a complete circle.  
     
     
         12 . The apparatus of  claim 1 , wherein each of said radiation emitting elements has a first effective width and each of said second elements has a second effective width less than said first width.  
     
     
         13 . The apparatus of  claim 1 , wherein said optical measuring assembly further comprises control means operatively connected with said source and with said unit and arranged to actuate selected groups of said first elements, to receive signals from said second elements, and to ascertain the transverse dimension of the article in said path on the basis of said signals.  
     
     
         14 . The apparatus of  claim 13  for ascertaining the diameters of at least substantially rod-shaped articles normally having predetermined diameters, wherein said control means is arranged to actuate selected groups of first elements and each of said groups has a length at least approximating one of said predetermined diameters, and to ascertain the diameter of the article in said path on the basis of (a) said predetermined diameters and (b) signals from those second elements which are screened from the groups of neighboring first elements by the article in said path.  
     
     
         15 . The apparatus of  claim 14 , wherein said control means is arranged to ascertain the diameter of the article in said path exclusively on the basis of signals transmitted from second elements which are fully screened from said groups of neighboring first elements.  
     
     
         16 . The apparatus of  claim 13 , wherein said first array is elongated and said selected groups of first elements are adjacent each other, said control means being arranged to actuate successive groups of first elements and said successive groups forming a row extending lengthwise of said first array so that the radiation issuing from said successive groups of first elements impinges at different angles upon the article in said path.  
     
     
         17 . The apparatus of  claim 16 , wherein said first array at least partially surrounds the article in said path so that said successive groups of first elements cause said second elements to generate signals suitable to be processed by said control unit to ascertain the curvature of that portion of the circumference of the article in said path which is being exposed to radiation by said successive groups of first elements.  
     
     
         18 . The apparatus of  claim 16 , wherein said control means includes means for processing the signals from said second elements into information denoting an average transverse dimension of that part of an article which is located in said path.  
     
     
         19 . The apparatus of  claim 13  for simultaneously ascertaining transverse dimensions of a plurality of at least substantially rod-shaped articles, comprising a discrete optical measuring assembly for each of said plurality of articles.  
     
     
         20 . The apparatus of  claim 19 , wherein the radiation sources and the evaluating units of said discrete assemblies are closely adjacent each other.  
     
     
         21 . The apparatus of  claim 1 , further comprising means for optically separating said first and second arrays from each other.  
     
     
         22 . The apparatus of  claim 21 , wherein said separating means comprises at least one diaphragm.  
     
     
         23 . The apparatus of  claim 21 , wherein at least one of said arrays forms an at least substantially complete circle and said separating means comprises a diaphragm having an opening for the article in said path.  
     
     
         24 . The apparatus of  claim 1 , wherein the radiation issuing from said source is at least substantially normal to the longitudinal extension of the article in said path.