the inner face of the pressing plate 9 is caused to press the switch piece 7 of the limit switch 5 through the rubber film 86 to actuate the switch 5 the stopper ring 96 is a stopper for inhibiting excessive intrusion of the projecting piece into the opening 85 and is caused to impinge against the face of the attachment plate 84 around the opening 85 if the long keyboard portion of the above described console panel is grasped by the left hand of a right handed operator from the left side face of the console panel while the surface having the display portion and keyboard portion is located above the tips of the four fingers located below are caught on the elliptical recess 91 and therefore the console panel can be easily grasped by dint of the inclined curved face c 9 around the recess and the inclined face on the end edge of the back plate 9 in addition to the recess furthermore whatever part of the pressing plate 9 is pressed the switch 5 is actuated and therefore even if the left hand becomes fatigued and the console panel is held in the slightly hung down state the dead man switch is always kept actuated moreover since the inclined face c 3 is formed on the back plate on the gripping side so that the fingers can be easily turned to the lower face a sufficient space for touching by the thumb can be formed on the end edge portion of the surface moreover since the opening of the switch substrate for insertion of the projecting piece 95 of the pressing plate is covered with the rubber film intrusion of dust into the interior of the.