The invention relates to a data register with a register card selection mechanism, whose selector keys connected with the swivel levers are arranged one behind the other and alongside one another in an opening of the housing in such a way that the width of each selector key corresponds to the width of the swivel levers, while the card restraining pins on each swivel lever are formed from U-shaped portions shaped onto the swivel lever end with a rod which engages from below in the register card opening, the drawer being open at the back and at both sides, whereby the two lateral drawer limiting walls are formed by two boundary walls shaped onto the inner wall surface of the housing cover and arranged on either side of the plate-shaped drawer base and whereby the swivel levers are guided on the end carrying the card restraining pin, while the drawer unlocking mechanism comprises a U-shaped shackle directly responsible for the locking and unlocking of the drawer.

A card index comprises a housing containing a drawer which holds a stack of punched cards. All the cards have punched holes in which a row of dogs in the bottom of the drawer engage and the cards also have punched selection holes in which selection stop cams can engage. Each card has selection holes in register with all of the stop cams except one. To select a card, a button corresponding to the card is pressed and this rocks a key lever to move the corresponding stop cam downwards. The cam passes through the selection holes in all the cards until it reaches the selected card which has no hole in register with that cam. Accordingly, the selected card and the cards, if any, below are pressed downwards and are held on the dogs. The drawer is released by depression of the button and is opened by a spring. As it opens, the drawer moves the cards which are pressed down on the dogs out of the housing with the selected card on top, but the cards above the selected card are retained in the housing by the stop cam. The arrangement has the great advantage over existing card indexes that it is not necessary to arrange the cards in any particular sequence in the stack in order for them to be correctly selected.

The invention relates to a card index which can be fixed to a vertical wall or vertically mounted on a base, in which the index cards are held by means of clamping devices in a receiving compartment formed in covered manner in the upper part of the index casing and are individually released on operating a selection key and transferred into the lower area of the casing provided with a window-like opening for inspection, the cards being secured and locked in the clamping device, so that a reliable release of the selected cards is possible, including those cards made from a material with a smooth surface such as e.g. plastics foil and in which incorrect manipulations are not possible.