Tube rack and clamp system

Abstract

A test tube rack includes top and bottom plates. Openings in the top plate are aligned with corresponding cavities formed in the bottom plate. The two plates are spaced apart and secured together by legs which are reinforced by internally embedded dowel pins. Respective test tube clamps fit snugly in respective openings in the top plate. The clamp includes a ring section with a first set of downwardly extending fingers which grip a test tube in a first plane substantially parallel to the top and bottom plates. The ring also carries a second set of fingers which grip the test tube in a different plane so the test tube is automatically aligned to be substantially perpendicular to the top and bottom plates.

1 . A test tube clamp comprising: 
 a ring defining a substantially flat plane;    a first set of flexible fingers secured to the ring to extend away from the flat plane and toward each other; and    a second set of flexible fingers secured to the ring to extend toward each other and away from the ring in the same direction as the fingers of the first set, the fingers in the first set being longer than those in the second set.    
     
     
         2 . A test tube clamp according to  claim 1  in which the fingers in each set are about the same length.  
     
     
         3 . A test tube clamp according to  claim 1  or  2  in which the fingers in each set terminate in a separate respective common plane substantially parallel to the flat plane defined by the ring.  
     
     
         4 . A test tube clamp according to  claim 1  or  2  in which the flexible fingers in the first set are about twice as long as the flexible fingers in the second set.  
     
     
         5 . A test tube clamp according to  claim 1  or  2  in which the distal ends of the longer fingers are more closely spaced than those of the shorter fingers.  
     
     
         6 . A test tube clamp according to  claim 1  or  2  in which the fingers in each set are spaced at substantially equal intervals around the ring.  
     
     
         7 . A test tube clamp according to  claim 6  in which each finger in one set is disposed between adjacent fingers in the other set.  
     
     
         8 . A test tube clamp according to  claim 1  or  2  in which the longer fingers in the first set are curved so that each finger presents a convex surface facing toward the other fingers in the first set.  
     
     
         9 . A test tube rack including a generally rectangular top shelf superimposed over a corresponding generally rectangular bottom shelf, said top shelf having an array of openings and said bottom shelf having an array of cavities corresponding to and vertically aligned with said array of openings, each cavity capable of receiving an end of a test tube having a maximum diameter and including an aperture of a lesser diameter extending vertically therethrough, 
 a flange formed along a side of said rack and including an alignment marker formed therein,    a plurality of inserts inserted into openings of said array of openings, each insert including an upper annular ring releasably secured within said corresponding opening and including a first set of fingers extending downwardly and centrally from said annular ring and having free lower ends terminating at a first depth and a second set of fingers extending downwardly and centrally from said annular ring and having free lower ends terminating at a second depth, said first depth being different from said second depth, 
 wherein each insert is capable of retaining a test tube having an outer diameter being less than or equal to said maximum diameter, such that the longitudinal axis of said test tube is coincident with the center axis of said opening.  
   
     
     
         10 . A test tube rack including a generally rectangular top shelf superimposed over a corresponding generally rectangular bottom shelf, said top shelf having an array of openings and said bottom shelf having an array of cavities corresponding to and vertically aligned with said array of openings, each cavity capable of receiving an end of a test tube having a maximum diameter and including an aperture of a lesser diameter extending vertically therethrough, and 
 a flange formed along a side of said rack and including an alignment marker formed thereon.    
     
     
         11 . A test tube rack according to  claim 9  or  10  which includes a plurality legs formed integrally with the top shelf, and a dowel pin in each leg and extending into the and bottom shelves.  
     
     
         12 . A test tube rack according to  claim 11  in which the top shelf and legs are formed integrally of plastic, and each dowel pin is made of metal.