US3542357A

US3542357A - Sheet feeder

Info

Publication number: US3542357A
Application number: US729054A
Authority: US
Inventors: Stanley T Stoothoff
Original assignee: North American Rockwell Corp
Current assignee: Boeing North American Inc
Priority date: 1968-05-14
Filing date: 1968-05-14
Publication date: 1970-11-24
Anticipated expiration: 1987-11-24

Description

United States Patent [72] Inventor Stanley T. Stoothofl' Glen Rock, New Jersey 21] Appl. No. 729,054 [22] Filed May 14,1968 [45] Patented Nov. 24, 1970 [73] Assignee North American Rockwell Corporation Pittsburgh, Pennsylvania a corporation of Delaware. by mesne assignments [54] SHEET FEEDER 19 Claims, 14 Drawing Figs.

[52] U.S. Cl 271/8, 271/11 [51] Int. Cl B65h 7/00 [50] Field ol'Search 271/3-8, 10,11,45,69, 75,63, 27.36, 56,57

[56] References Cited UNITED STATES PATENTS 1,691,606 11/1928 Hitchcock..... 271/47 2,467,423 4/1949 Bruker 271/69 Primary Examiner-Richard E. Aegerter Att0meysDale A. Bauer, John L. Seymour and Bauer and Seymour ABSTRACT: Apparatus for feeding sheets in sequence. In the illustrative embodiments the apparatus feeds sheets one by one from a conveyor to a sheet processing apparatus. The first and second illustrative embodiments of apparatus include sheet feeding means including an intermittently driven conveyor, constantly driven means for grasping and conveying one at a time sheets presented thereto by the conveyor, and a third sheet feeding means such as a pinch roll set receiving sheets from the sheet grasping and conveying means. The apparatus includes a clutch interposed between all of the feeding means and the driving means therefor whereby all parts of the feeding means may be stopped simultaneously. The apparatus also includes means which detects the presence or absence of sheets at the sheet grasping feeding means and which renders the incremental driving means for the conveyor operative when the number of sheets at the sheet grasping feeding means falls below a predetermined desired minimum value and which renders it inoperative when the sheets at the sheet grasping feeding means equals or exceeds such predetermined minimum number.

In a third illustrative embodiment of apparatus, which is otherwise of the same general construction as the first two embodiments, the conveyor is driven by a motor at such speed as to tend to maintain a desired number of sheets at the sheet grasping and conveying means at all times. The speed of driving of the conveyor is determined by manual adjustment of a variable speed driving mechanism therefor. The motor which drives the conveyor is controlled by a mechanism which includes a sheet detecting means. The motor-controlling mechanism is so constructed and arranged that when the number of sheets at the sheet grasping means equals or exceeds a predetermined desired number the conveyor-driving motor is stopped.

Patentd Nov. 24, 1970 Sheet L of 5 INVENTOR. STANLEY T. STOOTHOFF gm MW ATTORN YS Patented Nov. 24, 1970 Sheet Q of5 INVENTOR.

STANLEY T. STOOTHOFF 5m Md ATTORN YS Patented Nov. 24, 1970 Sheet ATTORNEYS Patented Nov. 24,- 1970 4 3,542,357

INVENTOR.

STANLEY T. STOOTHOFF ATTOR EYS Patented Nov. 24, 1970 Sheet N we INVENTOR. STANLEY T: 'STOOTHOFF 5m paw/d ATTORN YS l S'IIEETFEEDER SPECIFICATION This invention relates to a sheet feeder; in the illustrative embodiments; it relatesmore particularly to a sheet feeder which may be fed by a conveyor which forwards sheets in overlapped relation to the feeder, the feeder grasping and forwarding the thus presented sheets one by one to a processing apparatus such as a sheet buckle folder. The apparatus herein shown includes a first feeding means such as a belt conveyor, a second feeding means such as a constantly driven vacuum roll which grasps the leading sheet presented to it and forwards it, and a third feeding means, in the form of a set of pinch rolls at least one of which is constantly rotating when the sheet feeder is in operation, to which sheets are forwarded by the second feeding means. The present invention includes novel mechanism wherebythe first feeding means and the second and third, constantly rotating feeding means, are rendered inoperative at the same time by the disengagement ofa clutch.

The apparatus also provides means for detecting the presence or absence ofat least a predetermined minimum number of sheets at the sheet grasping feeding means, and means responsive to the detecting means to control the conveyor. In a first condition, when at least such predetermined minimum number of sheets are detected at the sheet grasping feeding means, in the first embodiment (FIGS. 1**7, inclusive) and the second embodiment (FIGS. 8 and 9) the step-bystep driving means for the conveyor is disengaged, and the conveyor is stopped. In a second condition, when less than such number of sheets are present at such location, the stepby-step driving means for the conveyor is rendered operative,

so that the conveyor is again driven to forward sheets to the sheet grasping feeding means. In the embodiment of FIGS. 10, 11, and 12, the conveyor is driven by a motor through a manually adjustable variable speed driving mechanism. Means is provided for stopping the conveyor driving motor under the first condition, and for driving the conveyor at the speed determined by the adjustment of the variable speed driving mechanism under the second condition.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition ofthe limits ofthe invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a view in side elevation of an illustrative embodiment of sheet feeder in accordance with the invention with the outer guard or closure therefor removed, the view being taken in the direction from the bottom to the top of FIG. 4 from the line 1-1 of such FIG., the parts of the apparatus being shown in the positions they assume when there is no sheet at the second, sheet grasping feeding means, the pawl of the driving means for the step-by-step driving means for the conveyor which forwards sheetsto the second feeding means being shown approaching the fully retracted terminal position in the idle or return stroke ofits oscillatory travel;

FIG. 2 is a fragmentary view in elevation of a portion of the ratchet and pawl mechanism of FIG. 1, the pawl engaging a tooth on the ratchet wheel and approaching the end of the operative or feeding stroke of its oscillatory travel;

FIG. 2a is a view similar to FIG. 2 with the pawl elevated and latched into its upper, inoperative position, after a finger on the pawl-carrying member has engaged an adjustable abutment on the frame of the mechanism at the terminus of the operative stroke of the pawl;

FIG. 2b is a view similar to FIG. 2a with the pawl held in its upper, inoperative position and withthe pawl carrying body at the end ofits idle stroke, the parts beingshown in the positions which they assume when a sheet is present at the second, sheet grasping feeding means;

FIG. 3 is a fragmentary view in vertical transverse section through the sheet feeder, the section being taken along the broken section line 3-3 of FIG. 1;

FIG. 4 is a view partially in plan and partially in horizontal section through the upper portion of the apparatus as it is shown in FIG. 1, but with the outer guard present thereon;

FIG. 5 is a fragmentary view in vertical longitudinal section through the apparatus, the section being taken along the broken section line 5-5 of FIG. 4;

FIG. 6 is fragmentary view in end elevation of the apparatus in the vicinity of the clutch for controlling the entire feeding apparatus and a portion of the control linkage therefor, the view being taken from the line 6-6 of FIG. 1;

FIG. 7 is a view in generally horizontal section through the pawl and the upper portion of the pawl-carrying member, the section being taken along the line 7-7 of FIG. 1;

FIG. 8 is a fragmentary view in side elevation of an alterna tive, electrically operated detent mechanism which may be employed in the ratchet and pawl mechanism of the apparatus ofFIGS. 1-7, inclusive;

FIG. 9 is a fragmentary view in side elevation of a sheet detecting mechanism for controlling the detent mechanism of FIG. 8;

FIG. 10 is a fragmentary view in side elevation of an alternative conveyor driving mechanism which may be substituted for the ratchet and paw] mechanism of the apparatus of FIGS. I 7, inclusive;

FIG. 11 is a fragmentary view in vertical section through the mechanism of FIG. 10, the section being taken along the line 11-l1 of FIG. 10; and

FIG. 12 is a fragmentary view in elevation of the mechanism of FIG. 10, the view being taken from the line 12-12 of FIG.

GENERAL DESCRIPTION OF THE APPARATUS The sheet feeder illustrated in FIGS. l7, inclusive, which is generally designated 10, is fed by an intermittently driven conveyor 11' (FIG. 5) which forwards sheets to a vacuum roll feeder 32 which is constantly driven. The sheets, of which one is shown at 68, are delivered by conveyor 11' in overlapped relationship, with the leading end of the uppermost sheet extending to the left, toward a vacuum feeder 32 of known construction, beyond the leading end of the next uppermost sheet, which it overlies. The vacuum feeder 32, which has a perforated periphery, grasps the uppermost sheet 68 as the sheet is presented thereto and forwards it to a'feeding means includ ing a roll 26, which is constantly driven when the feeder is operating, and an upper, idle roll which presses the sheet against the driven roll 26.

Rolls

26, 130 forward sheets to a sheet processing apparatus (not shown) which may be, for example, a sheet buckle folder.

The feeder 10 includes a clutch 23, which may be either manually or automatically operated, which when disengaged stops the conveyor 11', the vacuum roll feeder 32, and the roll set 26, 130. A testing roller 69, which is periodically lowered toward sheet supporting members 67 below the vacuum roll feeder 32-, detects the presence or absence ofa predetermined minimum number of sheets 68 on such members. When such number of sheets are detected by roller 69, the step-by-step driving means for the conveyor 11 is temporarily disengaged from its source of power and the conveyor 11 is stopped, so that no more sheets are forwarded thereby to the vacuum roll feeder 32. When the testing roller 69 in its downward stroke detects less than said predetermined minimum number of sheets on supports 67, the step-by-step driving means for the conveyor 11 is engaged or rendered operative, so that feeding of sheets to the vacuum roll feeder 32 by the conveyor 11 is resumed.

DETAILED DESCRIPTION OF THE APPARATUS As shown in FIG. 1,'the apparatus ofthe invention, which is generally designated by the reference character 10, has two laterally spaced vertical parallel plates or frame members 11 and 12 which are secured in spaced position by a number of spacer members of which some are shown at 14 (at the left in FIG. 4), 15 (at the right in FIG. 4), and 16 (at the lower part of FIG. 3). The apparatus has a main driven shaft 21' upon which is mounted a pulley 18 which is. freely rotatable with respect to the shaft, the pulley being driven by a V belt 19. Parts 18', 19', and 21' correspond to the

parts

18, 19, and 21 of the apparatus which is shown in FIG. 1 of the application of Owen Gore, Ser. No. 729,l2l,filed May 14, 1968, which is assigned to the assignee of the present application. Where other parts are herein referredto by primed reference character such parts correspond to parts referred to in the Gore application without the primes.

A clutch generally designated 23, which may be either automatically or manually operated, selectively drivingly connects the pulley 18 to the shaft 21 and drives a feed roll 26 which may be mounted upon and keyed to the shaft 21' or may be made integral therewith. The pulley 18", the clutch 23, and the ratchet and pawl driving mechanism (FIGS. 2-3) for the conveyor 11', both be described, are protected by a guard 22 which is hinged to plate 11 at 24 and which is secured in closed position by a latch 25.

At the end of the shaft 21 immediately adjacent the'frame plate 12 there is a pinion 27 which is affixed to the shaft so as to rotate therewith. As shown most clearly in FIG. 5, gear 27 meshes with an idler gear 28 which in turn meshes with an idler gear 29, and gear 29 meshes with a larger gear 30 which is keyedto a shaft 31 journaled in the frame plates 11 and 12 forwardly or to the right of the roll 26. A guard 38 mounted upon frame plate 12 covers the gears 27-30. The shaft 31 by reason of its driving connection to roll 26 rotates in the opposite direction from roll 26 and at a substantially slower speed. Affixed to the shaft 31. as by set screws (not shown) is a suction roll 32 which is connected through conduit 36 to a source of vacuum (not shown) by a hollow fitting 34 which is mounted upon the cross member 15 by an adjustable clamping means 35. The roll 32'may thus be adjusted to any desired position along the length of the shaft 31. The suction roll 32, which has a perforated periphery, is provided with stripper wires 37 which extend beneath the roll and partially around it so that a sheet 68 picked up by the roll 32 is progressively released therefrom as the sheet travels to the left toward the

rolls

26, 130. By means of suitable known rotary valve mechanism (not specifically shown), the suction to roll 32 is cut off when the sheet being forwarded thereby is engaged by feed rolls 26,130.

Shaft 31, which passes outwardly through a guard 39 similar to guard 38, has a gear 40 affixed to its outer end. A gear 41 ((FIGS. 3 and 4) which meshes with gear 40 is mounted upon and affixed to a stub shaft 46 supported in a bearing 47 within an opening in the frame plate 11. Secured to the gear 41 and rotatable therewith is a cam 42 which lies laterally inwardly of the gear. A cam follower roll 44 mounted upon an arm 45 bears upon the periphery of the cam,'the arm 45 being secured by a clamping hub 48 to a rock shaft 71, to be described hereinafter, which controls the action of the ratchet and pawl driving mechanism for the intermittently driven conveyor 11.

THE RATCHET AND PAWL MECHANISM Eccentrically mounted upon the outer end of shaft 46 is a crank pin 49 having a roller 50 thereon. An oscillatory pawlmounting member 51 has a wide vertical slot 52 therein adjacent its upper end, the slot receiving the roll 50 whereby to oscillate the member 51 about an axis 70' adjacent its lower end upon the rotation of the shaft 46. The means for mounting the member 51 takes the form ofasleeve 54, the inner end of which is mounted in an opening through the frame plate 11 and the outer end of which is received within a bore 55 in the lower end of the member 51. The sleeve 54 also serves to receive a sleeve bearing 56 within which the outer end of a cross shaft 70** is journaledfJournaled upon shaft 70' for the ratchet wheel cooperating with a pawl 79 mounted upon the member 51 in a manner to be described. Also mounted upon the outer end of shaft 70' is a ratchet wheel masking plate 61 having an upper arcuate nose portion 62 coaxial with and of slightly greater diameter than the outer ends of the teeth of the ratchet wheel 69. The plate 61, which is freely rotatable upon the shaft is retained in adjusted position about the shaft by a machine screw 64 which extends through an arcuate slot (not shown) in the bottom of the plate 61, the screw 64 being mounted upon a pedestal 65 secured to the frame plate 11. The portion 62 of the masking plate serves to lift the tooth 63 of the pawl 79 from contact with the teeth on the ratchet wheel so that a desired number of ratchet teeth may be fed forward by the pawl upon each operative stroke of the pawl.

The step-by-step turning of the shaft 70 by the ratchet and pawl mechanism turns a sprocket 73' which is keyed to shaft 70'. Sprocket 73' serves to power the conveyors of the sheet feeder disclosed in the Gore application Ser. No. 729,121, referred to above. Thus the chain of the Gore apparatus is entrained over and driven by the sprocket 73 of the present mechanism.

as above noted, sheets fed rearwardly by the conveyor 11 pass to sheet supporting strips 73 and thence to the strips 67 beneath the suction feed roll 32. Laterally displaced from the suction feeder 32 and slightly overlapping one of the strips 67 there is a testing roller 69 mounted upon the outer end of a testing roller lever 70 which in turn is fixedly secured by its hub 76' to the above mentioned rock shaft by a key 72, as shown in FIG. 5. The angular position of the lever 70 with respect to the rock shaft 71 is thus fixed. A counterweight 74 which is screwed upon a threaded stud 75 affixed to the hub of the lever allows the roller 69 and the lever 7t) to be suitably counterbalanced so'that they are lightly urged downwardly, whereby the cam follower roll 44 is constantly urged toward the cam 42. The cam 42 has an extended circular cylindrical zone of larger radius, the remainder of the cam in a zone 109 thereof (FIG. 2) being made up of a surface of smaller radius and ramps connecting such surface to the larger radius part of the cam surface. The testing roller 69 and the lever 70 are thus raised and lowered once for each revolution of the shaft 46 by the interaction ofthe cam 42 and the cam follower 44 through the medium of the cam follower lever 45 which is affixed to the rock shaft 71 by the clamping hub. 48.

The shapes of the upper end of the pawl mounting member 51 and of the pawl body 79, and their manner of connection are shown in FIGS. 1- -2b and 7. A wing 76 extends rearwardly from the upper end of the pawl mounting body 51, there being a generally oppositely extending rounded ear 77 on the other edge of the body. The pawl tooth 63 extends downwardly from the rear end of the pawl 79. The pawl 79 is pivotally mounted upon a shouldered stud 80 which is secured in a bore in ear 77' of member 51, as most clearly shown in FIG. 7. Secured to the laterally outer surface of wing 76 is a body 81 within which is mounted a pawl retaining or latching plunger 82 having a rounded forward end, the plunger being constantly urged forwardly by a coil compression spring, as shown in FIG. 7. The forward end or nose of plunger 82 fits within a seat 84 in the rear edge of the pawl when the pawl is lifted into its upper, inoperative position, as shown in FIGS. 2a

and 2b, and stably latches or retains the pawl in such position.

When the pawl is turned counterclockwise relative to member 51, in a manner to be explained, a sharp-edged detent projection 85 on the pawl 79 above the seat 84 rides over the nose of the plunger, thereby retracting the plunger and freeing the pawl so that it may pivot counterclockwise to assume either of the positions shown in FIGS. 1 and 2. In such positions, that is, when the pawl is released, the nose of plunger 82 engages the ramplike surface above projection 85. and urges the pawl downwardly so that the tooth 63 ofthe pawl either engages the nose 62 ofthe mask 61 (FIG. 1) or is operatively engaged with the teeth of the ratchet wheel (FIG. 2).

A finger 86 integral with the pawl 79 rises generally vertically above the pawl body slightly rearwardly of the pivot pin 80. Finger 86 selectively interacts with the head 87 of a rear abutment screw 89 (FIG. 2a), to lift the pawl into its inoperative, latched position (FIG. 2a), and interacts with a detent 91 (FIG. I) to release it from such inoperative position. Thus at the end of each rearward stroke (to the left) of the upper end of the pawl mounting body 51 the finger 86 engages the abutment 87 so that if the pawl body 79 has been in its lower. operative position it is turned clockwise somewhat into the position shown in FIG. 2a. As the pawl is thus turned, the nose of the plunger 82-snaps over the projecting detent portion 85 on the pawl and falls into the seat 84 thereon.

The-rear abutment screw 89 lies generally horizontal and is adjustably received within a threaded bore in a fixed support 88, screw 89 being held in adjusted position by a lock nut 90. The detent 91 is formed as a body attached to and depending from the forward end of a lever arm 92, such body having a shallow notch in its lower rear corner. Lever arm 92 forms a portion ofa first-class lever which is mounted to oscillate upon a horizontal pivot pin 94. The lever is counterbalanced by a weight 95 which is adjustably screwed upon a stud 96 which forms the second arm ofthe lever.

The arm 92 is movable between a lower position (FIG. 1), wherein it abuts the head of a lower vertical adjusting screw 99 mounted upon the fixed support 88, an upper position (FIGS. 2, 2a, and 2b) wherein the lever engages the lower end of an upper vertical adjusting abutment screw 97 which is adjustably mounted upon a fixed support 100. The weight 95 is so adjusted that unless the lever arm 92 is thrust downwardly by a pin 104 on a lever 101 (to be described) the lever arm 92 remains in its upper position in engagement with abutment 97. In the upper position of lever arm 92 the detent 91 carried thereby is elevated above the upper end ofthe finger 86 on the pawl, so that the finger passes forwardly past the detent when the pawl mounting body 51 is near and is passing through the terminus of its forward movement, as shown in FIG. 2b. The pawl body, having been elevated and latched into its inoperative position by the interaction of the finger 86 with the abutment screw 87 (FIG. 2a) thus remains in such position when the parts have the relationship shown in FIG. 1b.

When the lever arm 92 is depressed by lever 101 and pin 104 into its lower position, in engagement with abutment 99, the detent 91 on the forward end of arm 92 is interposed into the path of the upper forward edge of the finger 86 on the pawl. As the member 51 and the pawl 79 thereon approach the forward terminus of their return or inoperative stroke, the finger 86 engages the detent 91 as shown in FIG. 1, thereby to turn the pawl counterclockwise about its pivot pin 80 so that the nose of the plunger 82 rides up out of seat 84 and over the detent edge 85 on the pawl, thereby releasing the pawl so that it falls downwardly into its operative position.

THE CONTROL OF THE RATCHET AND PAWL MECHANISM As above noted, the testing roller 69 is periodically lowered toward the paper supports 67 by the interaction of the cam 42 and the cam follower roller 44 through the medium of the lever arm 45 secured to the rock shaft 71 to which the testing roller supporting arm 70'is also secured. Also secured to the rock shaft 71 and oscillating therewith is a further, rearwardly projecting lever 101, the hub 102 of which is adjustably held upon the rock shaft 71. The rear end of lever 101 carries a laterally projecting pin 104 which is positioned to engage the upper surface ofa serrated collar 106 which is affixed to a vertical screw 105. Thelower end of the screw is threadedly received in a passage in the lever arm 92 adjacent the pivotal mounting 94 therefor, the screw 105 and thus the collar 106 being held in vertically adjusted position with respect to the lever arm 92 by an L-shaped resilient leaf spring detent 107 mounted upon the

lever

92, 96, the lower end of the vertical portion of detent 107 engaging the serrated periphery of the collar 106.

The ratchet wheel 60, by means of which the conveyor 11 is intermittently driven, is prevented from rearward rotation by a second pawl 1 11 which is formed on the forward end of a lever 110. Such lever is mounted in a suitable bracket for rotation about the axis of the spacer rod 112 and is constantly urged against the periphery ofthe ratchet wheel by a coil tension spring 114.

The function of the above-described pawl and pawl controlling mechanism in conjunction with the ratchet wheel 60 will be better understood by considering FIG. 2. As there shown, a line through the axes of the crank pin 49 and the shaft 46 is disposedsomewhat forwardly of the center of the low zone 109 of the cam 42. the direction forward relating to the direction of rotation ofthe shaft 46 which in all of F 63. 1-2b. inclusive, is counterclockwise. It will thus be seen that the testing roller 69 is elevated when the high zone of cam 42 lies under cam follower roll 44, and that it is lowered toward the sheet support 67 when the zone 109 of the cam begins to enter beneath the cam follower roller 44. The parts are so arranged and adjusted that when the testing roller 69, upon being lowered toward supports 67 by the cam 42 and cam follower 44, encounters sheets on the supports 67 the cam follower is held elevated above a portion of the smaller radius zone of the cam.

For each rotation of the shaft 46, crank pin 49, and cam 42, the pawl-mounting member 51 completes one cycle of its oscillation. As the member 51 approaches its rear terminus of oscillation (FIG. 2a), the finger 86 on the pawl 79 engages the rearward abutment 87 so that if the pawl had previously been in the raised, inoperative position of FIG. 2b it remains in such position, and if the pawl had previously been in the lowered, operative position of FIG. 2 it is lifted into its upper, inoperative position. The pawl remains in such position upon its forward, return or inoperative stroke; whether or not the tooth 63 of the pawl engages the ratchet wheel 60 on its rearward, operative stroke depends upon how far down toward the support 67 the testing roller 69 descends when the low zone 109 of the cam 42 is under the cam follower roller 44.

When the testing roll 69 is lowered with less than the predetermined desired minimum number of sheets present upon the support 67, the rock shaft 71 rotates counterclockwise to lower the lever 101 so that the pin 104 on such lever engages the collar 106 on lever arm 92 and thus lowers the detent 91 into the path of the finger 86 on the pawl. Thus when the pawl approaches the terminus of its forward, inoperative stroke, the finger 86 engages the detent 91 and the pawl is freed from the nose of the plunger 32 to lie in the position shown in FIG. 1. Upon the subsequent rearward, operative stroke of the pawl, its tooth 63 first rides along the nose 62 of the masking plate 61 and then falls offthe masking plate to feed the ratchet wheel 60 through the number of teeth of the ratchet wheel determined by the adjustment of the masking plate 61.

When at leastthe predetermined minimum number of sheets are present upon the supports 67, the testing roller 69, upon being lowered toward the supports by the cam 42 and cam follower 44, rests upon such sheets and remains elevated above the supports. One such elevated position of roller 69 is shown in FIG. 2b, wherein it is assumed that a stack of sheets is present upon supports 67. The holding of the testing roller 69 in elevated position causes the rock shaft 71 to remain in an angular position which is clockwise from that shown in FIG. 1, and causes the pin 104 on lever 101 to remain spaced above the collar 106 on lever arm 92. The lever arm 92, which is now free to rotate counterclockwise under the influence of weight 95, rises to engage stop 97. In such position of the lever arm 92, the detent 91 is raised above the path of the finger 86 on the pawl and the pawl remains 'in elevated, inoperative position, held by the reception of the nose of the plunger 82 in the recess 84 on the pawl, during subsequent rearward or operative strokes of the pawl, during subsequent rearward or operative strokes of the pawl mounting member 51, so long as the testing roller 69, upon being lowered by cam 42 detects one or more sheets on supports 67.

THE OVERALL CONTROL OF THESHEET FEEDER The clutch 23. through which the sheet feeder is driven, is selectively engaged and disengaged by the manual operation ofa horizontal control rod 120. As shown in FIGS. 1,4. 5, and o, the forward or right-hand end of the. rod 120 is pivotnlly unted upon the lower end ol'u depending arm 121 having it huh 122 which is freely rotatable with respect to a horizontal rock shaft [19 upon which the hub is mounted. The outer end of rock shaft 199 extends through a sleeve in frame plate 11; outwardly of plate 11 the hub 124 of a rearwardly extending lever 125 is pinned to the rock shaft 119 (FIGS. 4 and 6). A thrust rod 126 is pivotally connected to the outer end of arm 125 and extends downwardly and forwardly to the operating mechanism for the clutch 23. Such mechanism includes a wedge 127 on rod 126, wedge 127 cooperating with an inclined surface 129 on a member 128 affixed to the plate 11. When rod 126 is thrust downwardly, the

inclined surfaces

127, 129 coact to disengage theclutch. Such disengagement of the clutch disconnects the pulley 18' from the main shaft 21' so that the conveyor 11, the vacuum feed roll 32, and the pinch rolls 26, 130 are stopped. When the rod 126 is restored to the position thereof shown in FIGS. 1, 5, and 6, the clutch 23 is reengaged.

The arm 121, which is actuated by the control rod 120, has a lost motion connection to the rock shaft 119. Thus the arm 121 has two angularly spaced laterally inwardly extending wings, the forward being shown at 131 and the rear wing at 133 (FIGS. and 6). A pin 132 through the rock shaft 119 has its lower end disposed between

wings

131 and 133. When the control rod 120 is thrust forwardly, the rear wing 133 on arm 121 engages the pin 132 to turn the rock shaft 119 counterclockwise to disengage the clutch 23. The rod 126 remains stably in its clutch-disengaged position until the rod 120 is pulled rearwardly; the arm 121 then turns clockwise until the forward wing 131 on the arm engages the pin 132 to turn the shaft 119 clockwise to engage clutch 23. The arm 125 and rod 126 are counterbalanced by a weighted lever arm 134 secured to rock shaft 119 as shown in FIG. 4.

Mounted upon spacer 14 are two similar clamping devices 135 (one only shown in FIG. 5) each having forwardly and upwardly inclined arm 136. A pair of similar bell cranks 137 are pivotally mounted on the respective arms 136 for movement in vertical planes. The presser roll 130 is journaled between the forward, lower ends of first arms 139 of the bell crank levers 137, such levers having second, rearwardly projecting bifurcated arms 140. Affixed to each clamp 135 there is a vertical, upwardly extending headed pin 141 which extends through the longitudinal slot in the respective arm 140. A lower coil compression spring 142, which is telescoped about pin 141, is disposed between arm 140 and the body of clamp 135; an upper coil compression spring 144 is telescoped about pin I41 and disposed between the head on the pin and the arm I40.

Springs

142 and 144 permit the presser roll to rise and fall while retaining it constantly urged toward the driven feed roll 26.

THE EMBODIMENT OF FIGS. 8 AND 9 In FIGS. 8 and 9'there are shown, respectively, alternative means for controlling the detent of the pawl and ratchet conveyor driving mechanism, and sheet detector means which may be substituted for the corresponding mechanisms in the embodiment of apparatus shown in FIGS. 1-7, inclusive. In

FIGS. 8 and 9 parts which are th e same as those in the embodiment of FIGS. 1-7, inclusive, are designated by the same reference characters.

The detent controlling means of FIGS includes the lever arm 92 pivoted at 94 on the frame of the apparatus and provided with a counterweight 95. The detent 91 on the end of arm 92 is elevated out of engagement with the finger 36 on pawl 79 when at least a predetermined desired number of sheets are present on the sheet supporting means 67 (FIG. 9). The arm 92 is selectively pivoted clockwise to interpose the detent 91 into the path of the finger 86 by the fol owing means. An arm 1511 is secured to the lever arm 92 by a screw 151 disposed above pivot 94, the arm 1511 extending in the same direction as arm 92. A rod 152, which is adjustnbly secured to arm by u out 15 extends downwardly to a solenoid which is mounted upon fixed structure, not shown. A pivotal connection between the plunger of the solenoid and the lower end of rod 152 is effected by a cross pin 157. The counterweight 95 is so adjusted that when the solenoid 155 is d'eenergized the arm 92 lies in its uppermost position with the detent 91 withdrawn from the path of the finger 86. When the solenoid 155' is energized, arm "9?? is rotated clockwise to lower the detent 91 into the position shown in FIG. 8, wherein it is engaged by the finger at the end of the inoperative stroke of the pawl mounting member so as to free the pawl 79 from its retaining means (82, FiG. 2) so that the pawl then engages the ratchet wheel in its next operative stroke.

The sheet detector for controlling the solenoid 155 is shown in FIG. 9. Such detector includes a bracket 159 which is mounted upon the crossmember 15 of the apparatus for adjustment therealong, the bracket being held in position by a clamping screw 160-. A horizontal bar 161 extends forwardly from the bracket 159, a further bracket 162 being mounted for adjustment longitudinally of the bar 161. A first-class

lever having arms

164 and 166 is mounted upon the bracket 162 by a pivot pin 165. A sheet detector roll 169 is pivotally mounted upon the rear free end of the lever arm 164. A counterweight 167 is adjustably mounted on the free end of the lever arm 166, the counterweight being adjusted so that the

lever

164, 166 is constantly urged in a counterclockwise direction and the detector roll 169 seeks the position shown in FIG. 9.

A microswitch 168 is mounted upon the bracket 162, such switch when closed completing a circuit including the wires L, and L a current source 153, and the solenoid 155. The microswitch 163 has a plunger 170 which when thrust upwardly as shown in FIG. 9 closes the switch and when extended downwardly opens the switch. An adjustable abutment 171 mounted upon the lever arm 166 in alinement with the plunger 170 is so adjusted that the switch 16? opens when the

lever

164, 166 is rotated clockwise to a predetermined extent by a desired number of sheets lying upon supporting means 167 and engaged at the-top of the stack by the detector roll 169.

THE EMBODIMENT OF FIGS. 10,11, and 12 In FIGS. 10, 11, and 12 there is shown a mechanism for driving the shaft 170 for the conveyor drum 169, such mechanism driving the drum at a predetermined speed when up to a predetermined desired number of sheets is present upon the sheet support 67 and stopping the conveyor when more than such number of sheets is there present. As shown in FIGS. 10 and 12, a bracket 175. which is mounted upon a leg 172 of the apparatus, supports driving mechanism in the form of an electric motor 176 which drives the drum 169 through a reducing gear unit 177. Also attached to the frame of the apparatus is a variable speed control unit 178 having selectively manually adjusted. A

suitable gear motor

176, 177 is a dc shunt motor made and sold by the Von Weise Gear Company, St. Louis, Mo., and designated VW 47-1297-1. The variable speed control 178 in this instance may be one designated VW 68-1 made by the same company.

The gear motor'drives the drum 169 through a sprocket 182 on the output shaft 181 of the gear motor and a chain 184 which is entrained over sprocket 182 and a further sprocket 185 on the shaft 170 which mounts the drum. The shaft 170 is journaled in two similar spaced parallel frame plates of the apparatus, of which one is shown at 174.

A circular crossrod 186 extends between and is secured to the spaced parallel frame plates of theapparatus. The crossbar 186 serves to support a sheet detector feeler 199 which extends upwardly to above the upper surface of the sheet support 67 and between successive fingers 200 thereof as shown in FIG. 11. For this purpose a clamp 187 is provided, such clamp having spaced parallel upper and lower fingers which closely embrace the rod 186. A bracket plate 188 which extends forwardly of the rod 186 is provided with a laterally extending flange 189 having its upper and lower edge portions secured to but spaced from the forward ends of the fingers of the clamp 187. Thus a lower screw 190 extends through the lower finger and into threaded engagement with a hole through the lower edge of flange 189, such screw being provided with a lock nut 191. An upper screw 192 extends through the upper finger of the clamp into threaded engagement with a hole through the upper edge portion of the flange 189. The screw 192' is selectively tightened and loosened by use of a knob 194 thereon, whereby the clamp, the bracket 188, and the switch supporting means to be described attached thereto may be adjusted both longitudinally of the bar 186 and angularly thereabout.

A second bracket plate 196 is pivotally mounted upon the upper forward corner of the plate 188 by a pivot pin 195. Fixedly mounted upon the .upper end of the plate 196 is a microswitch 197 having the above described feeler 199 secured to its plunger. The switch 197 and the motor control 178 form parts of a conventional circuit including a current source, the parts being so constructed and arranged that when the upper end of the feeler 199 is thrust to the left (FIG. to a predetermined degree the motor 176 is stopped and when the feeler is in its uppermost position or is not thrust to the left to such predetermined degree the motor rotates to drive the conveyor at the speed determined by the setting of knob 179.

The mechanism shown includes means whereby the bracket 196 maybe rotated about the pivot pin 195 so as to change the elevation of the upper end of feeler 199 with respect to the sheet support 67. Thus the bracket plate 188 is provided with a laterally extending flange 201 and the bracket plate 196 is provided with a second laterally extending flange 202 disposed above the flange 201. A screw 204 having an enlarged head extends upwardly through a longitudinally extending slot in flange 201 in which it is freely rotatable into threaded engagement with an alined hole in the flange 202. A coil compression spring 206 telescoped about the screw between the

flanges

201 and 202 constantly urges the enlarged head of the screw upwardly into engagement with the flange 201. Turning of the screw 204 by a knob 205 on the head of the screw in reverse directions selectively moves the plate bracket 196 clockwise and counterclockwise whereby both to adjust the upper end of the feeler 199 to the desired height above the upper surface of-sheet support 67 and its angularity with respect thereto.

A transversely extending air pipe 210 provided with a source (not shown)' of air under pressure is positioned to direct jets of air upwardly from alined holes (one shown) in the pipe through theinterstices in support 67 in order partially to supportthe leading edges of sheets as they are presented to such support and to lift .the leading edge of the topmost sheet toward the sheet grasping and conveying vacuum wheel. A similar air pipe 210 is also employed in the first described embodiment as shown in FIG. 5. The feeler 199 is secured to the plunger of switch 197, which is opposed by a spring (not shown) which normally maintains the switch closed. When a predetermined number of sheets, which may be as few as one, depending upon the adjustment of the feeler 199,v is present upon support 67 in position to thrust the feeler 199 suffciently to the left, the switch is opened. This deenergizes the motor 176 and stops the conveyor. With a suitable adjustment of the parts including feeler 199, however, the conveyor is driven almost continuously, the sheet grasping and conveying means taking sheets from support 67 at substantially the same speed as they are delivered to the support by the conveyor.

Although only a limited number of embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions ofthe parts, materials used, and the like, as well as the suggested manner of use ofthe apparatus of the invention, may be made therein without departing from the spirit and scope ofthe invention. as will now be apparent to those skilled in the art.

lclaim:

1. Sheet feeding mechanism comprising a conveyor for forwarding sheets, a first continuously driven sheet feeding means fed by the conveyor and feeding forward sheets presented thereto by the conveyor, a second constantly driven sheet feeding means receiving sheets from the first sheet feeding means, common means for driving the conveyor and the first and second sheet feeding means, and means simultaneously to disconnect the conveyor and both the sheet feeding means from the common driving means.

2. Sheet feeding mechanism according to claim 1, wherein said means to disconnect comprises a selectively operated clutch, the common driving means is connected to the second sheet feeding means through the clutch, and the first sheet feeding means and the conveyor are driven from the second sheet feeding means.

3. Sheet feeding mechanism according to claim 2, comprising means for driving the conveyor from the first sheet feeding means.

4. Sheet feeding mechanism according to claim 3, wherein the second sheet feeding means has at least one driven roll, the common driving means is connected through the clutch to said one driven roll at a first end of such roll, the first sheet feeding means comprises a second roll mounted on a shaft, and the means for driving the conveyor comprises means for connecting a first end of the shaft to the conveyor, and comprising means drivingly connecting the other, second end of said one roll to the other, second end of the shaft.

5. Sheet feeding mechanism, comprising a belt conveyor for forwarding lapped sheets, a driven sheet feeding means fed by the conveyor and feeding forward one at a time sheets presented thereto by the conveyor, means to continuously drive the sheet feeding means, means for detecting the presence of sheets in position to be fed by the sheet feeding means, and means responsive to the detecting means during operation of the sheet feeding means to render operative the means for driving the conveyor only when less than a predetermined number of sheets are present in said position.

6. Sheet feeding mechanism according to claim 5, wherein the means for driving said conveyor is independent of the means for driving the sheet feeding means and is responsive to the detecting means to vary the rate at which the conveyor forwards sheets to the sheet feeding means.

7. Sheet feeding mechanism according to claim 5, comprising means for supporting sheets in said position to be grasped by the sheet feeding means, and wherein the means for detecting the presence of at least said predetermined number of sheets in said position comprises a feeler engaged by sheets at said position.

8. Sheet feeding mechanism according to claim 7, comprising means for cyclically moving the feeler toward and away from the sheet supporting means.

9. Sheet feeding mechanism according to claim 7, comprising electrically energized means for controlling the driving of the conveyor, a current source for the last named means, and switch means operated by the feeler.

10. Sheet feeding mechanism according to claim 9, wherein the feeler is constantly urged downwardly toward the sheet supporting means and is thrust upwardly by sheets on the supporting means, and the switch means is connected to increase the speed of feeding of sheetsby the conveyor when less than a predetermined number of sheets is present on the sheet supporting means. v v i 11. Sheet feeding mechanism according to claim 5, wherein the means for driving the conveyor includes a prime mover, a manually adjustable variable speed driving mechanism driven by the prime mover for driving the conveyor, and means responsive to the detecting means for stopping the prime mover when at least said predetermined number of sheets are present in said position.

12. Sheet feeding mechanism according to claim 11, comprising means for supporting sheets in said position to be grasped by the sheet feeding means, and wherein the means for detecting the presence of at least a predetermined desired number of sheets in said position comprises a feeler which projects upwardly through the sheet supporting means and is actuated by sheets on the sheet supporting means.

13. Sheet feeding mechanism according to claim 5, wherein the means responsive to the detecting means to control the driving of the conveyor disconnects the conveyor from its driving means when at least said predetermined number of sheets are present in said position.

14. Sheet feeding mechanism according to claim 5, comprising sheet supporting means disposed adjacent the sheet feeding means, wherein'the sheet detecting means comprises a rock shaft, a lever arm affixed to the rock shaft and having a sheet engaging feeler means affixed to its free end and overlying the sheet supporting means, and means for cyclically moving the feeler toward and away from the supporting means, the parts being so constructed and arranged that a stack of at least said predetermined number of sheets on such supporting means, the top sheet of which is engaged by the sheet engaging feeler means on the lever arm, supports the feeler means above its lower terminal position.

15. Sheet feeding mechanism according to claim 14, wherein the means for cyclically moving the feeler comprises a constantly driven cam, and a cam follower on a lever arm, the cam follower being supported by and following the surface of the cam except when there is at least a predetermined number of sheets between the sheetsupporting means and the feeler means.

' 16. Sheet feeding mechanism comprising a conveyor for forwarding sheets, a driven sheet feeding means fed by the conveyor and feeding forward sheets presented thereto by the conveyor, means to drive the conveyor and the sheet feeding means, the means for driving the conveyor including an intermittent grip driving means connected to the conveyor whereby the latter is intermittently driven, means for supporting sheets in position to be fed by the sheet feeding means, and means for detecting the presence of at least a predetermined number of sheets in said position, said detecting means being operable to disable said intermittent grip driving means and maintain the same in disabled condition when there is at least said predetermined number of sheets at said position.

17.. Sheet feeding mechanism according to claim 16, wherein the intermittent grip driving means includes a ratchet wheel drivingly connected to the conveyor, a pawl cooperating with the ratchet wheel, oscillating means mounting the pawl for driving the ratchet wheel, means responsive to the sheet detecting means for moving the pawl toward the ratchet wheel, and means for maintaining the pawl in spaced relation to said wheel when there is at least a predetermined number of sheets present in position to be fed by the sheet feeding means.

18. Sheet feeding mechanism according to claim l7, comprising an abutment engaged by the pawl at the end ofeach of its strokes in its operative, conveyor driving direction to lift the pawl from engagement with the ratchet wheel, and wherein the means responsive to the sheet detecting means comprises detent means selectively movable into the path of the pawl to engage the pawl during its return, inoperative stroke when there is less than said predetermined numberpf sheets in said posit1on to free the pawl from the means maintaining it in spacedrelation to the ratchet wheel, whereby it is free to engage the ratchet wheel on its operative stroke.

19. Sheet feeding mechanism as defined in claim 16 wherein the intermittent grip driving means dri ably connects the sheet feeding means to the conveyor.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3, 542 ,357 Dated November 24 1970 Stanley T. Stoothoff Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 10, line 50 after "means insert means for driving the conveyor,

Signed and sealed this 13th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR Attesting Officer Commissioner of Patents