of the upper portion 118 a middle portion 122 of the shaft 102 extends between the upper portion 118 and the lower portion 120 the axis of the middle portion 122 in this embodiment forms an angle with both the axis of the upper portion 118 and the axis of the lower portion 120 in the embodiment of fig4 7 the angle is selected to be in the range of about 15 degrees to about 30 degrees in one embodiment an angle of 22 5 degrees is selected a beveled portion 124 is located at the end of the shaft 102 opposite to the handle 106 and an enlarged portion 126 is located between the coupling member 108 and the lower portion 120 of the shaft in the embodiment of fig4 6 the handle 106 is formed separately from the shaft 102 while the beveled portion 124 the enlarged portion 126 and the coupling member 108 are integrally formed with the shaft 102 any or all of these components may alternatively be formed integrally or separately referring to fig8 9 the head 104 includes a base 130 a spring 132 a retaining pin 134 a shuttle 136 and a pair of arms 138 and 140 the proximal portions 142 and 144 of the arms 138 and 140 are joined to the base 130 while the distal portions 146 and 148.