Patent GB-736199-A (GB)
Title: List finders
IPC: B42F17/34
Filed: 1954-03-29
Abstract: 736,199. Selector mechanism for filing papers ; indexing. NEILSEN, H. L. March 29, 1954 [Oct. 23, 1953], No. 9189/54. Classes 16 and 146(1). A list finder, such as a telephone index, comprises a base, a cover pivoted thereto, a stack of sheets between base and cover having separate marginal tabs, a number of keys associated with the base each having an operating portion and a portion to coact each with a different tab to separate one of the sheets and partially pivot that sheet and any other above it, as well as the cover, away from the base, sheet holding means movable into holding engagement with the partially pivoted sheet after the partial pivotal movement and to constrain the sheet or sheets thereabove to pivot with the cover to open position, restraining means being provided to prevent the sheet holding means from moving into engagement with the sheets until the completion of the partial pivotal movement. The device comprises a base 12 comprising a rear wall 14, side walls 16 having a downward slope 92 near the front to extensions 66, a front wall 18, and a bottom 20 having an inlay 22 on which a stack of sheets or cards 24 rest, each card 24 having a pair of slots for engagement with a pair of arcuate prongs 28 secured to a cover 30. The cover 30 is hinged to the base 12 by a rod 32 passing through the side walls 16 and side walls 34 of the cover which lie inside the walls 16 in the closed position with an overlying flange 50 to limit the closing, the cover 30 having a back wall 36 clear of the back wall 14 which swings inwardly as the cover is opened, to rest against a pair of stops 38 extending upwardly for the base 12 when the cover is substantially vertical. The front wall 40 of the cover 30, which is shorter than base 1, 2, has a dimple 42 to receive the bent upper end 44 of a resilient catch 46 fixed to the base 12 which holds the cover closed against the action of springs 48 round rod 32 which bias the cover to open position. In the open space in front of the cover bounded by the extensions 66, a series 52 of operating keys are mounted, each key comprising a lever 62 mounted on a rod 64 and having lifting finger 74 lying under the tab 58 of the stepped marginal edge 56 of its corresponding card 24, the height of the finger portions 74 being successively greater from one side to the other. Pressure on the front portion 72 of any lever key 62 presses on underside of the card 24 selected to lift the cover free from the catch 46 when the spring 48 will lift the cover to the vertical position. To retain the lifted cards with the cover, the bail 54 comprises a bent wire 78 extending across the device with ends 80 bent back and inwardly through holes 82 in the side walls 34 of the cover to form pivots 84 about which coil springs 88 are mounted to press the bail 54 into position underlying the cards 24. The ends 86 of the wire are bent to engage the inside of the cover when the bail is in sheet engaging position. As the cover is closed, the bail 54 is pressed along the slope 92 of the side walls 16 to lie out of engagement with the sheets or cards 24. The lifting finger 74, which has been used to open the device, is pushed downwardly on closing the cover and a press bar 94 may be fixed directly over the tabbed edges .56 of the sheets to assist action between cover and fingers 74. Alternatively the fingers 74 may be weighted to return to normal position as soon as released, or springs could be provided to return the fingers. Rubber feet 96 may be provided. The friction catch 46 may extend upwardly between two approximately central levers 62 or as shown, the central lever may be bored as at 76 to provide a clear space for the catch 46. As shown, thirteen keys 52 are provided marked with two letters of the alphabet corresponding with similarly marked tabs 58 on the cards 24, the keys 52 being spaced by washers 70.