may be selectively positioned at any location on the plate 11 defined by a mounting orifice 14 in a second embodiment shown in fig4 the expansion fingers 16 are mounted at specific locations on the plate 11 in either embodiment it should be noted that the expansion fingers 16 are defined by a plurality of elongated segments 17 integrally formed for flexing about an axial opening which has an enlarged diameter 18 proximal plate 11 the enlarged diameter may be defined by an internal shoulder 19 such that the portion of the segments 17 have a reduced thickness near the plate 11 an annular base 21 circumscribes the enlarged diameter and provides structural connection between the otherwise unconnected segments 17 the base 21 may be threaded into a portion of mounting orifice 14 or may be otherwise detachably and reattachably connected therein orifice 14 may have an enlarged portion for receiving the annular base 21 as may be seen in fig1 3 in the first embodiment the stripper plate 12 has a plurality of receptacles 22 formed therein for detachably and reattachably affixing a plurality of pins 23 which are aligned with the fingers 16 in the second embodiment shown in fig4 these pins are positioned in fixed alignment with the fingers 16 each pin 23 includes an upper shaft like portion which is insertable within the axial opening of the finger 16 and has a diameter sufficient to urge the elongated section 17 radially outwardly upon insertion into said opening in as s much as a uniform spreading of the segments is desired the pin may be lightly tapered to.