SE8101431L - reading device - Google Patents

Abstract

This patent application describes a completely mechanical lock which can be controlled by means of a punch card. In a lock housing consisting of a bottom 1 and sidewalls 2, 3, 4 there is a spring-loaded lock cylinder 7. Above this and in contact with its upper side, there is a thick plate 13 and over that another thick plate 12. Between both of these plates there is a slit 20 in which a punch card can be inserted. Through both plates 12, 13 and down in the cylinder 7 a number of cylindrical holes 10 are drilled. In the plate 12 the holes have a smaller diameter in the upper part than in the lower part. In each hole there is from the bottom a spring 11, three cylindrical units 16, two balls 15 and on top a bolt with a head 14. Based on a randomly selected pattern, a number of hoods 18 can be placed on top of the bolts 14 and locked in their positions by the lid 5 for the lock housing. Thus the bolts 14 equipped with hoods 18 are pressed down where the surfaces between the upper and the middle cylinder 16 will come in a plane with the interface between the lock cylinder 7 and the plate 13. If a punch card with holes only at the places that correspond to the hood-equipped bolts 14 is now inserted into the slit 20 to the fully inserted position, the cylindrical unit 16 under the bolts 14 which are equipped with hoods 18 will not be affected while the punch card goes in between both balls in all other cylindrical holes and thus presses down the cylindrical unit 16 so that the interface surface between the lower and middle cylinder reaches the same plane as the surface between the lock cylinder 7 and the plate 13. Thus the lock cylinder can move freely in a horizontal plane. Only the same combination of hoods 18 and corresponding holes in the punch card will release the lock cylinder 7. <IMAGE>