Alligator clip adapted for smaller plug

Abstract

An alligator clip ( 10 ) whose rear end was originally manufactured to receive a 4 mm plug ( 50 ), is altered to received a 2 mm plug ( 60 ), in a construction that provides a long lifetime of low force insertion and removal and low electrical resistance contact. The sheet metal rear portion with adjacent edges ( 40, 42 ) at the top, is deformed so a bottom part forms an approximately 360° loop ( 130 ), a pair of vertical bottom beams ( 131, 132 ) extending upward from the loop, and a pair of part-cylinders ( 140, 142 ). The part-cylinders create a cylinder contacting region ( 150 ) at the top of the beams to grip the cylindrical 2 mm plug. Upper beams ( 152, 154 ) extend generally upwardly from the upper ends of the part-cylinders.

What is claimed is  
     
         1 . An alligator clip with a body formed of two pieces of bent sheet metal having front ends and a spring that biases said front ends together, with a first of said pieces of sheet metal having a rear end forming a pin jack, wherein said pin jack includes a gripping section having an axis and having parallel and adjacent sheet metal top edges lying above said axis with said edges unjoined to each other, wherein: 
 along said gripping section of said pin jack, said sheet metal has a bottom portion where said sheet metal forms primarily vertical bottom beams with lower ends joined at a bottom loop, and above said bottom beams said sheet metal forms two continuous part-cylinder portions that each extends from an upper end of one of said bottom beams and with said part-cylinder portions together forming a cylinder region centered on said axis to hold and engage a cylindrical pin.    
     
     
         2 . The alligator clip described in  claim 1  wherein: 
 along said gripping section of said pin jack, said sheet metal forms a pair of upper beams that each extends upwardly from an upper end of one of said part-cylinder portions to one of said edges.  
 
     
     
         3 . The alligator clip described in  claim 2  wherein: 
 said bottom beams each has a length that is at least 150% of the length of each of said upper beams.  
 
     
     
         4 . The alligator clip described in  claim 1  wherein: 
 said first piece of sheet metal has an intermediate part lying between said first piece front end and said pin jack, with said intermediate part having a flat bottom that lies in a horizontal plane and side walls that extending upwardly from opposite sides of said flat bottom;  
 said first piece of sheet metal has a predetermined sheet metal thickness;  
 said top edges lie above said horizontal plane and said bottom loop has a bottom that lies below said horizontal plane by a distance (P) that is at least twice the thickness of said sheet metal.  
 
     
     
         5 . The alligator clip described in  claim 1  wherein: 
 said piece of sheet metal has a predetermined thickness and said bottom beams are horizontally spaced apart by a distance that is at least 150% of said sheet metal thickness.  
 
     
     
         6 . The alligator slip described in  claim 1  wherein: 
 said bottom loop extends in a bend of at least 300°.  
 
     
     
         7 . An alligator clip which includes a first piece of sheet metal with a rear portion bent to form a pin jack that has a horizontal axis and that can receive a cylindrical plug, with said piece of sheet metal having a pair of parallel edges at the top of said rear portion, wherein: 
 said rear portion has a gripping section extending about said axis when viewed in a sectional view taken along said axis, where said gripping section has a bottom part that forms an approximately 360° loop and a pair of primarily parallel bottom beams that extend upwardly from opposite sides of said loop;    said gripping section has gripping section opposite sides each bent to engage locations at opposite side portions of said cylindrical plug, said gripping section sides lying at the top of said bottom beams, with said gripping sections sides together forming a region to stably receive said plug and engage.    
     
     
         8 . The alligator clip described in  claim 7  wherein: 
 said gripping section has a set of primarily parallel upper beams that extend primarily upwardly from upper ends of said gripping section sides, with said parallel edges lying at the tops of said upper beams.  
 
     
     
         9 . The alligator clip described in  claim 8  wherein: 
 said bottom beams each has a height that is at least 150% the height of each of said upper beams.  
 
     
     
         10 . The alligator clip described in  claim 7  wherein: 
 said first piece of sheet metal has a predetermined thickness;  
 said approximately 360° loop has a sufficient radius that said bottom beams are spaced apart by an average of at least 150% of said thickness.  
 
     
     
         11 . A method for application to an alligator clip that has a first piece of sheet metal with a rear end having laterally opposite sides and forming a pin jack with a first cylinder which is of a predetermined first diameter, for closely receiving and connecting to a large cylindrical plug of predetermined first diameter, where the method is useful to convert the pin jack so it can closely receive and connect to a second cylindrical plug of a second diameter that is less than said first diameter, wherein said rear end of said first piece of sheet metal has parallel and unjoined edges at a top of said first cylinder, comprising: 
 deforming a bottom portion of said cylinder to laterally compress said bottom portion and thereby form about a 360° loop at the extreme bottom and to leave primarily parallel sides extending upwardly from opposite sides of said loop;    deforming said laterally opposite sides of said first cylinder into opposite final sides that lie on horizontally spaced sides of an axis and that engage said second plug and that resist movement of said second plug away from said axis, with said unjoined edges lying above said axis.    
     
     
         12 . The method described in  claim 11  including: 
 deforming an upper portion of said first cylinder into two upper beams each extending upwardly from a top of one of said opposite final sides to one of said edges.  
 
     
     
         13 . The method described in  claim 11  wherein: 
 said first piece of sheet metal has a predetermined thickness;  
 said step of deforming a bottom portion of said cylinder includes deforming it to an outside radius of curvature that is at least 150% of the thickness of said sheet metal.  
 
     
     
         14 . The method described in  claim 11  wherein: 
 said first piece of sheet metal has an intermediate portion lying forward of said first cylinder, said intermediate portion having a bottom lying slightly above a bottom of said first cylinder;  
 said step of deforming a bottom portion includes positioning said loop so its bottom lies lower than the bottom of said first cylinder relative to the bottom of said intermediate portion.