simplified schematic front cross sectional side and back representations of chuck assembly 70 elements of structure that previously have been discussed are similarly designated as shown in fig1 a chuck assembly 70 is provided with a housing 180 having a substantially planar forward surface 182 having a central aperture 185 therethrough radially inward of central aperture 185 are a plurality of chuck jaws 71 twelve such chuck jaws are shown in this figure and it can be seen in fig1 b that more than one row of jaws are employed in this specific illustrative embodiment of the invention chuck jaws that are located proximal to cam plate 187 are designated as chuck jaws 71 and those that are disposed axially inward are designated chuck jaws 71 u2032 cam plate 187 controls the rate of actuation and the centralization of three of chuck jaws 71 one of which is controlled chuck jaw 71 u2033 the two other controlled chuck jaws are not shown in this cross sectional representation the operation of cam plate 187 has been described hereinabove in connection with fig5 chuck assembly 70 is as previously stated rotatable in response to electric motor 56 not shown in this figure and drive belt 57 not shown in this figure the chuck assembly is rotated on bearings 190 shown in fig1 b.