hammer via the tool receiver 20 tipping ball 26 and trigger element and indeed to some extent by the sleeve 12 and the rest of the device 10 which by their mass and associated resistance to sudden acceleration in a direction opposite to the movement of the hammer directs more of the kinetic energy into the tool piece and thus to the workpiece this is further illustrated in fig3 in that the eyelet can be seen deforming under the blow delivered to it depending on the operation being performed a single blow or multiple blows can be delivered as the device is self resetting the user simply again applies pressure while the tool piece 32 rests on the workpiece 42 as will be appreciated between blows when pressure on the device e g via the end cap 28 and sleeve extension grip portion 18 is removed by the practitioner not shown the device resets to the initial or neutral position state as the return spring 22 pulls the trigger element 24 down out of the hole 48 in the bottom of the hammer 14 the tipping ball 26 then cooperates with the return spring to tip the trigger element askew to again rest against the inside of the sleeve in the narrow guide portion 30 as shown in fig1 the return spring pushes all the elements out again to.