US3561755A - Document feed mechanism - Google Patents

Abstract

The invention pertains to a document feeding mechanism for selectively lowering a document deck to engage a feed roll to effect sequential feeding of documents from the hopper. The document supporting bed is controlled by a cam driven articulated pivot latch which is magnetically actuated to cause the articulated portions to be locked to one another for pivoting as a unitary structure.

Description

United States Patent Inventor Boyd M. Brue Rochester, Minn. Appl. No. 770,505 Filed Oct. 25. 1968 Patented Feb. 9, 1971 Assignee International Business Machines Corporation Armonk, N.Y. a corporation of New York DOCUMENT FEED MECHANISM 3 Claims, 3 Drawing Figs.

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Field of Search [56] References Cited UNITED STATES PATENTS 3,383,106 5/1968 Brown 271/44 3,279,790 10/1966 Steinke et al. 271/41 Primary Examiner-Ev0n C. Blunk Assistant Examiner-Joseph Wegbreit Attorney-Hanifin and Jancin and Robert W. Lahtinen ABSTRACT: The invention pertains to a document feeding mechanism for selectively lowering a document deck to engage a feed roll to effect sequential feeding of documents from the hopper. The document supporting bed is controlled by a cam driven articulated pivot latch which is magnetically actuated to cause the articulated portions to be locked to one another for pivoting as a unitary structure.

PATEN'TEU FEB 919m m), gm

ATTORNEY 1 DOCUMENT FEED MECHANISM BACKGROUND OF TH E INVENTION When processing unit record documents such as cards through high speed processing machinery the documents must be rapidly and timely supplied by a feeding mechanism in a predetermined manner, usually singly in sequence and without damage. This is accomplished either by feed knives or friction rolls or belts. With elevated speeds and the consequent high initial acceleration the use of feed knives is likely to damage the documents. The alternative feed rolls or belts must be selectively brought into engagement with the document stack and overcome the friction between adjoining documents to shear the endmost document from the remainder of the stack. The control of the feed must be positive in effecting sufficient frictional engagement causing neither irregular or interrupted document feeding. The control must be positive and not subject to erratic functioning which would permit uncontrolled actuation resulting in document jams or erroneous operation.

SUMMARY OF THE INVENTION In the document feeding device of the present invention, a continuous running feed roll drives one card at a time from the stack supported in the hopper. The feed roll is permitted to engage the document to be delivered by magnetic actuation which locks together articulated portions of a latch structure for unitary pivotal movement. One portion of the latch structure is fixed to the pivotable document supporting bed plate and the other portion has a cam follower surface. Accordingly when the latch structure pivots as a unit a document is engaged and fed into the device by the exposed feed roll. An emitter disc is secured to a common shaft with the cam and has associated therewith emitter pickups which initiate and terminate energization of the electromagnet in response to feed commands. Since the cam rotates at a speed which is a multiple of the feed rate of the associated device it is unnecessary to lose a full cycle if a delay occurs in the feed command since the latter can be executed during the next subsequent revolution of the cam.

It is an object of the invention to provide an improved document feeding apparatus which is positive in control action while simplified in structure. It is a further object of this invention to provide a document feed control actuable without the loss of a full cycle should a delay in the feed command occur.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view partly broken away of a portion of a parallel feed hopper including a pivot latch mechanism. FIG. 2 is a side elevation partly in section of a hopper utilizing the mechanism of FIG. 1. FIG. 3 is a side elevation of the latch mechanism of FIG. 1.

DETAILED DESCRIPTION As seen in FIG. 1 a bed plate shaft assembly includes a shaft 11 to which is secured a front bed plate 12, a latch frame 14 and a latch arm spring 16 to form a unitary structure. The latch frame 14 has secured rigidly thereto a pivot pin and an electromagnet core 18 with depending legs or core elements 19, one of which is surrounded by coil 63. Joumaled about pivot pin 20 is an oscillating latch arm 22 in the form of a bellcrank wherein one projection arm 23 serves as an armature confronting the electromagnet poles or core elements 19 and the other leg 24 presents a cam follower surface. A bed plate spring bracket 26 is secured along the web portion 27 thereof to the machine frame. Bracket 26 presents a flange 28 to which one end of main spring 30 is secured and a flange 31 which serves as an abutment against which the downwardly depending projection 33 of latch frame 14 is retained. An aperture in a depending projection 33 receives the opposite end of spring 30 with the biasing force of the spring exerted to normally retain projection 33 against the flange 31. The latch arm spring 16 is positively secured at one end to bed plate pivot shaft 11 with the opposite free end abutting the upper projection 35 of the pivot latch 22 to bias the pivot latch leg 24 into engagement with eccentric cam 39. The eccentric cam 39is secured to the cam shaft 40, rotated by a drive means not shown and has positively fixed thereto at its opposite end an emitter disc 42. The cam shaft assembly rotates in the direction of arrow A causing the emitter or emitter disc 42 to move past the emitter pick ups 44 and 45.

As seen in the schematic vertical section of FIG. 2. a card deck 47 is supported within the hopper, inclined against a rear sidewall 50 and further confined between a pair of end walls 51, one of which is shown. A series of continuously running feed rolls 53 secured to a common shaft 54 are interdigitatcd between the support tabs 55 to permit the support tabs to hold the card deck immediately above and out of engagement with feed rolls 53. The card deck 47 receives further support on the rear bed plate 56 while the hopper is provided with a threat knife 58 to insure delivery of one document at a time from the hopper to document guideway of the associated machine. Documents or cards initially moved through the throat beneath throat knife 58 by the driving force of the frictionally engaged feed rolls 53 thereafter are confined between the throat roll 60 and nudge roll 61 which assume control of the card and drive the card at the transport speed of the machine.

In operation the main tension spring 30, holding frame projection 33 against the stop of bracket flange 31 maintains the bed plate shaft 11 and front bed plate 12 in a rotational position whereat the support tabs 55 maintain the card deck 47 within the hopper in an elevated disengaged position with respect to feed rolls 53. Continuously driven cam shaft 40 causes cam 39 to drive the oscillating latch arm 22 against the biasing force of leaf spring 16 and pivot the annature 23 downward once during each rotation of the cam. During the fall of cam 39 latch arm 22 pivots allowing armature 23 to approach the pole faces of core elements 19, but at the low point of the cam a slight clearance is maintained between the armature and pole faces to prevent impact during each rotation of cam 39 which occurs while coils 63 are deenergized. The emitter pickup 44, which causes the magnet coil 63 to be energized, is positioned in a selected angular position prior to the low point of the cam profile to permit the magnetic force to build to the required value at the low point of cam 39. When a feed command is issued the next passage of the emitter past the emitter pickup 44 causes the electromagnet coil 63 to be energized and attract the armature 23 to the magnet pole faces of the core legs 19 thereby securing oscillating latch arm 22 to latch frame 14 as a unitary rigid portion of the bed plate shaft assembly. Oscillating latch arm 22, latch frame 14 and rear bed plate 12 now pivot as a unit causing the support tabs 55 to pivot downwardly exposing the upper driving surface of the feed rolls 53 to contact the lowermost card present in deck 47 and drive it beneath throat knife 58 to effect delivery from the hopper. When cam shaft 40 has rotated to the position to bring the emitter to a position confronting emitter pick 45. a signal is issued deenergizing the electromagnet coil 63 and freeing oscillating latch arm 22 for movement independent of the bed plate shaft assembly, whereupon the main tension spring 30 restores the latch frame projection 33 to abutting relation with bracket flange 31 and rear bed plate 12 is positioned with bed plate tabs 55 positioned to support card deck 47 above and out of engagement with the feed rolls 53. The signal from emitter pickup 45 occurs at a position of angular displacement prior to the bottom center position of cam 39 to allow the magnetic field to decay sufficiently to effect release of the armature at such bottom center position of the cam, thereby minimizing the impact forces as the frame projection 33 restores to a position of abutment with flange 31.

During each feed cycle the upwardly extending projection 65 of rear bed plate 12 pivots toward card deck 47 to provide a joggling action of the cards. This provides a card joggling capability that functions during each feed cycle.

The cam shaft 42 rotates at a rate that is some multiple of the desired document feed rate. As the consequence if there is a delay in the command for the next feed cycle, a feed com mand when issued will be executed on the next subsequent rotation of the cam shaft and accordingly only a fraction of a feed cycle is lost as a result of such delay. By way of example,

if the cam rotates at a speed four times the normal feed rate of 5 the hopper mechanism, a delayed feed command will cause a card to be fed during the next succeeding rotation of the cam which occurs during each quarter of the normal feed cycle. As a result only a quarter cycle is lost rather than a full cycle where a slight delay occurs in the feed command. Thus, depending upon the multiple of the feed rate at which the cam shaft operates, the delay occasioned by a late command from the associated processor is only one third, one fourth, one fifth, etc. of a normal document feed cycle.

lclaim:

1. Apparatus for feeding documents from a stack comprising:

a hopper;

a continuously driven feed member;

a pivotable means including a document supporting bed member selectively pivotable between a first position whereat a document stack supported on said bed member is retained above and out of engagement with said feed member and a second position permitting the lowermost document of said stack to engage said feed member whereby such document is sheared from said stack and delivered from said hopper;

a first element secured to said pivotable means for movement in unison therewith;

a second element pivotally secured to said first element;

drive means engaging and periodically pivoting said second element; and

electromagnet means mounted on said first element and selectively actuable to retain said elements fixed with respect to one another to cause said drive means to pivot said first and second elements in unison.

2. The apparatus of claim I wherein said second element comprises a bell crank pivotally connected to said first element with one arm that forms an armature adjacent the pole of said electromagnet and the other arm presents a cam follower surface and said drive means which engages said second element comprises a cam, whereby said second element is pivoted by each rotation of said cam and said first member. bed member and bell crank are pivoted as a unitary structure by said cam when said electromagnet is actuated.

3. The apparatus of claim 2 further comprising first biasing means urging said document supporting bed member toward said first position and second biasing means urging said bell crank and other arm toward engagement with said cam.

Claims (3)

1. Apparatus for feeding documents from a stack comprising: a hopper; a continuously driven feed member; a pivotable means including a document supporting bed member selectively pivotable between a first position whereat a document stack supported on said bed member is retained above and out of engagement with said feed member and a second position permitting the lowermost document of said stack to engage said feed member whereby such document is sheared from said stack and delivered from said hopper; a first element secured to said pivotable means for movement in unison therewith; a second element pivotally secured to said first element; drive means engaging and periodically pivoting said second element; and electromagnet means mounted on said first element and selectively actuable to retain said elements fixed with respect to one another to cause said drive means to pivot said first and second elements in unison.

2. The apparatus of claim 1 wherein said second element comprises a bell crank pivotally connected to said first element with one arm that forms an armature adjacent the pole of said electromagnet and the other arm presents a cam follower surface and said drive means which engages said second element comprises a cam, whereby said second element is pivoted by each rotation of said cam and said first member, bed member and bell crank are pivoted as a unitary structure by said cam when said electromagnet is actuated.

3. The apparatus of claim 2 further comprising first biasing means urging said document supporting bed member toward said first position and second biasing means urging said bell crank and other arm toward engagement with said cam.

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