Browse Prior Art Database

Paper Stack Lifter

IP.com Disclosure Number: IPCOM000062636D
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Alimpich, C: AUTHOR [+4]

Abstract

Bottom restacking of documents in a copier's automatic document feeder is facilitated by a mechanical lifting finger which is moved in a controlled manner by operation of a microprocessor-controlled (i.e., programmable) stepper motor. The document feeder may be of the type disclosed in U. S. Patent 4,456,235. (Image Omitted) Fig. 1 shows a side view of the entry end of the document feeder's generally horizontal table 10. This table is provided to hold a stack of original documents 11 which are to be copied by operation of a copier (not shown). After a document sheet has been copied, it is returned to the bottom of the stack by way of path 12 (Fig. 4). Another document sheet is then fed to the copier, from the top of the stack, by operation of a vacuum sheet feeder (not shown).

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Paper Stack Lifter

Bottom restacking of documents in a copier's automatic document feeder is facilitated by a mechanical lifting finger which is moved in a controlled manner by operation of a microprocessor-controlled (i.e., programmable) stepper motor. The document feeder may be of the type disclosed in U. S. Patent 4,456,235.

(Image Omitted)

Fig. 1 shows a side view of the entry end of the document feeder's generally horizontal table 10. This table is provided to hold a stack of original documents 11 which are to be copied by operation of a copier (not shown). After a document sheet has been copied, it is returned to the bottom of the stack by way of path 12 (Fig. 4). Another document sheet is then fed to the copier, from the top of the stack, by operation of a vacuum sheet feeder (not shown). Prior to bottom restacking of a sheet, the left edge of stack 11 is lifted (Fig. 4) by operation of a plurality of lifting fingers 13 which extend along the left entry edge of the stack. The forward movement direction of stepper motor 14 is shown by arrow 15. These parts are proportioned such that 100 steps of motor 14 produce 360- degree rotation of output member 16.

(Image Omitted)

Prior to starting a copy job, the position of fingers 13 is not known with certainty. Thus, motor 14 is initially rotated in the reverse direction for 104 steps, at a fast rate of 4 milliseconds (ms) per step. In this way, no matter what position the fingers 13 are in, member 16 is overdriven such that its pawl 17 engages spring- biased lever 18, and fingers 13 stop at a home position where the stack edge is elevated, as shown in Fig. 4. All future moves are based upon...