A method and apparatus for protecting a horizon­tally reciprocable light projector (8) from collision with a vertically reciprocable punch (1) of a button setting machine, wherein a lost motion mechanism (21) is provided for producing a delay between retracting movement of the light projector (8) and the downward movement of the punch (1) to such an extent that the light projector (8) is retracted from the vertical path of movement of the punch (1) before the punch (1) starts moving downward. The lost motion mechanism is composed of a shaft (16) having an annular actuating flange (18), and a cylinder member (17) slidably re­ceiving therein the shaft (16). The actuating flange (18) is normally separated from the cylinder member (17) and engageable with the cylinder member (17) to lower the punch (1) when the light projector (8) is retracted from the vertical path of movement of the punch (1).