and to the right a lower leg 116 of the pawl is spaced below leg 113 and is provided with a notch 117 in its end to substantially counterbalance pawl 108 about its pivot axis 109 a portion of the pawl extends to the left of the shoulder rivet 109 pawl 108 is mounted with its legs 113 and 116 located in close proximity to the forward surface of gear 84 in order to engage pins 91 as will be described in more detail a bracket 118 is secured to pawl 108 by a pair of rivets 119 bracket 118 includes a left leg 120 and a right leg 121 which are spaced rearwardly from the pawl and laterally from one another to project upwardly on opposite sides of shoulder rivet 109 a notch 122 is formed in the top end of leg 120 while a notch 123 is formed in the top end of leg 121 notch 123 preferably extends lower than notch 122 referring to fig3 and 4 a conventional switch 125 is mounted on frame 10 near the bottom thereof by a pair of screws 126 switch 125 includes a plunger 127 which is biased inside the switch in order to be urged upwardly at all times switch 125 is in series with the electric motor 71.