US2901250A - Automatic sheet stacker apparatus - Google Patents

Description

Aug. 25, 1959 Filed April l, 1957 G. M. MARTIN AUTOMATIC SHEET STACKER APPARATUS 4 Sheets-Sheet 1 Aug- 25, 1959 G. M. MARTIN 2,901,250

AUTOMATIC SHEET STACKER APPARATUS Filed April l, 1957 f 4 Sheets-Sheet 2 M v u 5 0 t @y N w la g s L/l ev Aug 25, 1959 G. M. MARTIN 2,901,250

AUTOMATIC SHEET STACKER APPARATUS Filed April l, 1957 Y 4 Sheets-Sheet 3 Aug. 25, 1959 G. M. MARTIN AUTOMATIC SHEET STACKER APPARATUS 4 Sheets-Sheet 4 Filed April l, 1957 MS uw ATTORNEY United States Patent O 2,901,250 AUTOMATIC SHEET STACKER APPARATUS George M. Martin, Emeryville, Calif.

Application April 1, 1957, Serial No. 649,867

22 Claims. (Cl. 271-68) This invention relates to automatic sheet stacker apparatus.

Heretofore, so-called sheet rstackers were provided primarily between a printer-slotter machine and the conveyors or pallets for carrying away from `the printing machines the printed slotted sheets such as cardboard sheets printed and slotted for preparing boxes. The purpose of such stackers is to receive the printed sheets from the printing and slotting machines and then stack the sheets in straight vertical stacks. The main disadvantages of stackers heretofore utilized was that as the stacker was rising substantially in proportion to the piling of the stack, the rate of speed varied and the outlet end of the stacker did not move on a truly perpendicular path, therefore it did not stack the sheets in straight stacks. Another disadvantage of such previous stackers was that the so-called layboy which rst received the sheets from the printer and slotter and by which these are transferred to the stacker did not coact with the stacker properly for continuous automatic operation.

The primary object of this invention is to provide a sheet stacker which is fully automatic and which is operated at a substantially uniform rate on a substantially perpendicular delivery path to raise uniformly and to pile the printed sheets on pallets into uniformly straight stacks; and which is automatically returned for the continuing operation of piling another stack as the rst pallet is lilled and cleared at a pre-set rate of return.

Another object of this invention is to provide a combination of stacker and the so-called lay-boy wherein the two are so united that the lay-boy works in synchronism with the movement of the stacker, yet can be easily swung into an out-of-the-way position.

Another object of the invention is to provide a novel device in stackers for piling of printed sheets on pallets or the like, for raising the delivery end of the stacker at a substantially uniform rate, and at the same time to move the stacker so that its delivery end is constantly maintained in the same vertical relation to the pallet so that it moves generally on a straight perpendicular line; means being provided for causing a lay-boy to move in synchronism with the swinging of the stacker while the stacker follows the raising of the pile of sheets.

l am aware that some changes may be made in the general arrangements and combinations of the several devices and parts, as well as in the details of the construction thereof without departing from the scope of the present invention as set forth in the following specification, and as dened in the following claims; hence I do not limit my invention to 'the exact arrangements and combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

With the foregoing and other objects in view, which will be made manifest in the following detailed description, reference is had to the accompanying drawings for the illustrative embodiment of the invention, wherein:

Fig. l is side view of a stacker constructed in accordance with my invention, shown partly in section at its lowered position.

Fig. 2 is a partly sectional view of my stacker in partially raised position.

Fig. 3 is a partly sectional view of my stacker and layboy combination at the top elevated position.

Fig. 4 is a fragmental partly sectional View showing the device on my stacker to stop the delivery of sheets in the highest elevated position of the stacker.

Fig. 5 is a top plane view of my stacker; and

Fig. 6 is a wiring diagram illustrating the electrical control of my stacker.

Fig. 7 is a fragmental detail plan view of the relative arrangement of the switch actuating cams and the respective switches for controlling the operation of the stacker mechanism;

Fig. 8 is a fragmental, partly sectional side view of side switch actuating cams and switches showing them in the position for lowering the stacker; and

Fig. 9 is a fragmental view of the wiring diagram showing the valve in by-passing position for the return movement of the stacker.

The basic parts of my device as heretofore known generally include a base 1 on which is swingably or pivotally mounted a stacker frame 2 having suitable cross-frame members 3, and a series of belt conveyors 4 mounted on suitable pulleys 6 and on tension pulleys 7 to deliver and carry sheets 8 and to pile them into a stack on suitable pallets or conveyors 9. A so-called layboy 11 is provided at the intake end of the conveyors 4 for the purpose of receiving sheets from a printing or slotting machine, not shown, and conveying them onto the stacker. However in my the layboy is such that it can be moved out o-f the way and give access to the printing machine when needed.

My invention includes a stacker elevating mechanism 12, the mounting and compensating fulcruming of the pivoted stacker on the base 1 for true vertical stacking; the relationship and particular combination with the swinging layboy 11 which facilitates operation and access to press set up and clearing; the power actuation of the layboy to move it to out of the way position; the mechanism 13 for stopping the sheets when the stacker reachesits highest elevated position and the top of the pile for which it was adjusted; and the convenient automatic actuation ofthe stacker.

At an end of the base 1 near the layboy 11 are pro-` vided a pair of brackets 14 aligned respectively with the opposite longitudinal sides 16 of the stacker frame 2. On each bracket 14 is pivoted an arm 15 which extends generally upwardly and has its upper end pivoted on the intake or receiving end of the stacker frame 2 and forms a journal for a conveyor pulley shaft 17 extended transversely across the intake end of the stacking frame 2. In this manner the stacker frame 2 is supported pivotally about the intake conveyor shaft 17 andalso swingably on the arm 15 fulcrumed on the lower pivots 18 of the arms 15 in the brackets 14 of the base 1. Thus the stacker frame 2 can be swung upwardly about the conveyor shaft 17 as a pivot, but this conveyor shaft 17 is shiftable generally horizontally in proportion and oppositely to the horizontal component of the normal arc oct pivotal movement of the frame 2.

For control of this compensating shifting ofthe stacker frame pivot, a bell crank lever 19 is journalled on a fulcrum 21 on a bracket 22 on the base 1. at each outside longitudinal side 16 of the skeleton frame 2 so that the lever arm 23 thereof initially extends toward the intake end of the stacker frame 2.

The relative location of the crank lever pivot 24 relatively to the length of the stacker frame 2 is such that Patented Aug. 25, 1959 delivery en'dto moveon a generally*verticalline' 28 lasindicated on Fig. 3.

Inthe present dimensions ofsaid stackerthis is accomplished b`y spacing the crank lever pivot 24 from'the pivotk shaft 217 or yfulcrum off the frameor about one-third ofthe length of the stacker'.- For instance, ona gl3 foot length stacker frame,-.fthe bell-crank pivot axis alignswith pivot axis in -the top of thefulcrum arm 15, substantially horizontally when the stacker frame 2 is horizontal or is within about 1 ofihorizontal. The bell cranklever hasa constantfcrank anglebutlthe arcuatefdrive y'hereinafter described has a shifting angle. Forthis purpose it is signicant that the stackeris'raised ina clockwise direc'- tion. around its pivot `shaft17, but the bell crank lever 19 turns ina contra-.clockwisedirection toaccomplish the said raising and negative shiftingof' the stacker. Thus asthe'bell crank lever 19 is turned'l in a contraclockwiyse direction Viewing-Fig. 3, so-that the crank lever'2'3 isturned toward the deliveryj oristacker end of the stacker, and `simultaneously the bell cranklever 23 is moved .upwardly and awayfrom the base 1,y it not only turns the entire stacker upwardly` in a clockwise direction, but it also lpulls the stacker frame so as to turn thepivot arms also in a contra-clockwise direction, and :allows they raisingl and-simultaneous swinging of the. stacker frame toward its Adelivery or stacker end` in such proportion as tomaintain the delivery or stacker end-ofthe stacker constantly inabout the sameV perpendicular plane. I n v L The mechanism for turning the bell crank 19 issuch as to apply a constant speed-ofturning. In the herein illustration the inner end of Yeach crank arm 26 of the bell crank lever 19 is in the form of a gear segment or toothed head 31 'the teeth of `which are in mesh with a suitable sprocketchainBZ." The anchor end .33 of the sprocket chain'32 lis anchored at the end of the head 31 nearest" to the delivery'end of the stacker frame 2. j

Thesprocket chain 32 is played over a segmental sprocket or rhead 34 and has its other Vend 35 lanchored on the end'of the segmental sprocket 34 farthest from the delivery end'of theA stacker frame 2. Thus the sprocket chain 32 engages'both 'sprockets generally tangentially With'res'pect 'to the arc of theheads or segments so that during the turning of the sprockets the chain 32 moves at a constant lineal speed and thus exerts pull upon the bell crank 19 at a constant speed, thus the pivotedend of lever arm 23 moves at afconstant peripheral speed.

The vsprockets l34 are fixed -on ya transverse shaft 36 whichisjournalled in vbrackets 37 on the base il. mediatebetw'een the ends ofthe shaft 36'is provided a transmission segment sprocket 38 whichis lixcd on the shaft 36.' A drive sprocket chain 39'is played over the teeth 'of the segmental dri-ve sprocket 38 and has an end 41 'thereof anchored on the end ofthe segmental drive sprocket )'38 nearest to the delivery endof the stacker I frame 2. The other end of the drive lsprocket chain 39 is secured to the end of a plunger rod 42 connected to 4a plunger`vvhich Works ina hydraulic or pneumatic cylinder 43.` "They cylinder 43 is connected by a'pivot 44 to a verticalfbracket'46 on the base 1. AA suitable conduit 47 conve'yui'd totheI hydraulic cylinder -415 which is controlled "by "suitable automatic device and valvel system. In the initial position, Where the stacker frame is in its lowermost position '(Fig'. l) the segmental drive sprocket 38 "is in a position Where its last teeth are in generally.

perpendicularposition with respect to the sprocket shaft 36 and las'pullisexerted on the plunger rod 42, by reason of -tleeng'agernent of the sprocket chain 39 always tangentiallyattheftopof the drive sprocket `38, the drive sprocket'38 is turnedat a constant Iperipheral speed.

In other words, drive is transmitted by the chains always through the teeth of the sprocket in line with the chain and the chain functions somewhat similarly to a rack of a rack and gear transmission. The principle of operation involves the application of a lineal generally parallel uniform pull tangentially of the respective arcuate heads through a eXible `pulling line.

In my device a layboy isso arranged that it moves in synchronism with the relative shifting ofthe position of the stacker as heretoforejdescribed and Ain the same direction. My 1ayboy `11 includes a skeleton frame 52 side members 53 (Fig. 5) of which are journalled on the intake pulley shaft 17. layboypulley shaft 54 is journalled in the"side frame members 53 at the end thereof spaced from the previous journalled end. To a middle transverse box frame 55 is pivotally connected a uid operated plunger rod 56. The plunger of the rod 56 works in a iluid cylinder 57, the lower end of which is journalled on a base link 58. The base link 58 is in yturn journalled on a pivot 59 at the adjacent end of the base 1. An adjustable screw abutment 61 projects downwardly from the fluid cylinder 57 to determine parallelism or angle in the initial position of the layboy. The axis of the cylinder 57 is generally parallel with the arms 15 so` as to Afunction in` swinging as a parallelograml to maintain the layboy at level position.

A plurality of belt conveyors 62 are placed around pulleys 63 of the `layboy shaft 54 and also around pulleys 63 on the intake pulley shaft 17`of the stacker. The layboy is adjacent to the printer and slotter machine so that printed sheetsare fed upon the layboy at suitable height and are carried by the belt conveyors 62 vthereof unto the belt conveyors 4 on the stacker, and are carried by the latter belt conveyors 4 to the delivery end of said conveyors 4 and to the stack, as the stacker is moved upwardly in the manner heretofore described When the stacker reaches its uppermost elevated posif tion shown in Fig. 3,`then the pile is completed and the further piling of sheets is prevented until1 the stacker is lowered again. For `this purpose 'l provide a plurality of friction pads 71. Each pad 71 is supported on a spring arm 72 normally holding the pad 71 below the level of the belt conveyor 4, so thatv the pad can lbe pushed upwardly between adjacent stacker conveyors and against the respective sheets passing thereover.` As shown in Fig. 4, a cam shaft 73 extends transversely and is journalled in the side members 16 of the stacker, and carries a plurality of roller cams '74 positioned below the respective pads 71. As the shaft 73 is turned, it will turn the eccentric cams 74 so as to force the respective friction pads 71`against the adjacent sheets 8 as shown iu Fig. 4, and prevent their movement over and olf the stacker.

In the' present form the stacker 2 is covered by a wood flooring and the upper run of the conveyors 4 move over said flooring. The spring arms 72 are formed in this form by slits in the flooring separating'a strip which could be flexed upwardly sufliciently to bring 'the pads 71 into operative position when needed.A

For the actuation of this last described anti-friction sheet restraining device there is provided a solenoid 7 S, mounted on the stacker frame 2 which when energized pulls its core 79 inwardly so as to pull a link 81, thereby to turn a crank anm 82 which latter is keyed on the cam shaft 73, so as to turn the shaft 73 in contra clockwisedirection viewing Fig. 4. After the stacker is returned to its initial position, the solenoid 78 is deenergized and a coil spring 83 connected'to the crank arm S2 land anchored on an ear 84 returns the crank arm S2 'toits initial position and thereby allows the spring stiip 72 to lower the friction pad 71 below lthe level of thev stack conveyors 4 and allow the sheets to again passy off vthe end of said stacker frame 2 onto the'pile.

For the automatic control of the lowering and raising n of the stackerthere are provided 'cams' 91, 92' and' 93 on Ithe shaft 36 so that as the shaft 36 is turned in clockwise direction, viewing Fig. 7, during Ithe raising of the stacker, the cams 91 and 92 also turn in clockwise direction and are so adjusted that at the top position of the stacker the cams 91 and 92 engage respectively switches 94 and 96 for actuating the brake mechanism 13, and for bypassing the pressure medium from the hydraulic cylinder 43 thereby allowing the lowering of :the stacker mechanism. The third cam 93 is adjusted oppositely to the first calms 9]. and 92 so as to abut a switch 97 to brake a :relay electric circuit to be hereinafter described and release `the said brake mechanism 13 and connect the pressure medium to the hydraulic cylinder 43 for raising the stacker.

The sequence ofY operation is diagrammatically illustrated in the wiring diagram of Fig. 6 which explains the automatic operation and actuation of the stacker. In the cylinder 43 works a piston 98 on the end of the plunger rod 42. The pressure medium is introduced through the conduit 47 ahead of the piston 98 so as to push the piston inwardly of the cylinder 43 thereby to pull lthe plunger rod 42 andthe sprocket chain 39 so as to turn the sprockets on the transverse shaft 36 in clockwise direction viewing Figs. 1 and 2 for raising the stacker at a constant speed in the manner heretofore described. The pressure medium is provided through a pump 99 which takes the uid from a reservoir 101 through an intake pipe 102. Suitable valves are connected in the line 47 which for the sake of simplicity of diagrammatic illustration are represented by a three-way by-pass valve 103. This bypass valve 103 has a straight passage 104 for direct connection through the line 47. The valve 103 also has a by-pass connection 106 at right angles to one side so that when turned in a clockwise direction viewing Fig. 6, the passage "104 is aligned with a by-pass passage 107 leading back to the reservoir 101 and the bypass pas-sage 106 is aligned with the portion ,of the conduit 47 leading from the cylinder 43, as shown in Fig. 9. There is provided a suitable relief valve 108 in the pump circuit so that when the conduit 47 is blocked from the pump 99 the increase of pressure will operate the relief valve and by-pass the pump fluid back to the intake conduit 102 and the reservoir 101.

In the diagrammatic View in Fig. 6 the valve 103 is illustrated as a cock valve the handle 119 of which is turned by a link 109 connected to the core of a solenoid 111. Whenever the solenoid 111 is energized, it turns Ithe valve 103 into the by-passing position shown in Fig. 9. A

suitable spring 112 pulls the valve 103 back to its pressure position when the solenoid 111 is deenergized.

For clarity of illustration in the wiring diagram in Fig. 6, the three cams 91, 92 and 93 are shown separately adjacent to the exploded diagrammatic view o-f the three respective switches 94, 96 and 97.`

The switch 94 is for closing the circuit from line 113` to line 114 leading to the solenoid 111 from which latter a line 116 leads to the other terminal of the source of electricity. When rthe cam 91 closes the switch 94, the solenoid 111 is `energized and the bypass valve 103 is operated so as to bypass the pressure from the cylinder 43 and the pump and to allow the lowering of the stacker.

The switch 96 is for closing the circuit between line 113 and line 117 to the solenoid 78 of the brake device 13 which latter solenoid 78 is then connected to line 116 to the other terminal of the source of electricity.

The switches 94 and 96 are held normally open by any suitable device such asrsprings 118i. The cam 92 is advanced somewhat with respect to `the cam 91, as shown in Fig.` 8, so as to operate the brake device 13 slightly in advance of the lowering of the stacker.

Each of the switches 94 and 96 is held in a. circuit closing position by relays or solenoids 119 respectively. The intake lines 121 of the solenoids 119 are broken respectively by a switch 122 operably coupled with the switch 94 and 96 respectively, so that when the switches 94 and 96 are closed respectively by the cams 91 and 92, then the relay switches 122 are closed also so as to energize the solenoids 119 and thereby hold the switches 94 and 96 in circuit closing position until the stacker again reaches its lowermost position, as shown in Fig. 1. In this lowest position of 4the stacker the cam 93 abuts and opens the normally closed switch 97 for breaking the circuit in line 121 and thereby deenergizing the solenoids 119 and permitting the opening of switches 94 and 96 for the resuming of the raising of the stacker. For this purpose, the switch 97 is in series in the circuit with the intake line 121 and the relay solenoids 119 and is held normally in circuit closing position by suitable means such as a spring 123.

In operation the machine is started in the usual manner by turning on a main switch 124 in the line 121 (Fig. 6), which main switch also controls a motor 126 which through a suitable chai-n 125 drives the conveyor shaft 17.

Thus the conveyors are continuously in operation on both the stacker and layboy. Then the pump motor switch 127 (Fig. 6) is turned on for operating the pump motor 128 and thereby applying the pressure medium into the cylinder 43. As the piston 98 moves back into the cylinder 43, it pulls the plunger nod 42 which latter pulls the sprocket chain 39 and turns the segment sprockets and the sprocket shaft in the manner heretofore described so that the bell cranks are swung in a contra-clockwise direction viewing Fig. l.. This movement causes upward pivoting or lifting of the stacker end of the stacker about the conveyor shaft 17 and the simultaneous swaying of the supporting arms 15 and the layboy 11 in the opposite direction in proportion 'to compensate for and take up the horizontal component of the arc of movement of the stacker end of the stacker, with a resultant lineal vertical path of the stacker end of the stacker.` The conveyors 4 carry the sheets 8 on the stacker and deposit them in substantially true alignment in the vertical stack.

As the stacker reaches its uppermost position shown in Fig. 3, then rst the cam 92 closes the switch 96 to apply the brake device 13 for retarding movement fof sheets 8 on the stacker conveyors 4. Immediately thereafter the cam 91 closes the switch 94 for closing the circuit of the by-pass valve relay or solenoid 111 so as to turn the by-pass valve into the position shown in Fig. 9. The weight and leverage of the stacker device pulls the piston 98 with comparative rapidity down into the lowest dotted line position shown in Fig. 3.

The double switch arrangement of switches 94 and 96 causes the simultaneous closing of the relay switches 122 for energizing the solenoids 119 which keep the switches 94 and 96 in circuit closing position until the stacker is lowered into the lowest dotted line position shown in Fig. 3. When the stacker reaches this lowermost position, the release cam 93 engages the release switch 97 so as to open Ithe same and thereby deenergize the relays 119 and permit the opening of the switches 94 and 96, which in turn, results in deenergizing the solenoids 78 and 111 so that the brake device is released and the valve 103 is turned to connect the pressure medium from the pump 99 `to the cylinder 43 and thus resume the constant uniform raising of the stacker for stacking sheets as heretofore described. During this lowering and raising operation, the layboy swings correspondingly so as to feed in constant relation to the stacker conveyors and allow the aforesaid compensation for the varying horizontal components of the arc of swinging movement of the stacker.

The particular structure of the layboy also permits the easy lifting of the layboy about its pivot shaft by operating the hydraulic or pressure cylinder device 57 so as to push :the layboy up and into an out of the Way position. Before operation the layboy must be lowered into its operative position as shown. It is to be noted that even the pressure lifting device of the layboy is suitably pivoted to follow combination, a" base, 'a stackerframe having'a receivingl end and a stacking end and including 'a plurality' of conveyors' longitudinal on` said frame to carry sheets alongsaid frame from said receiving end to said stacking end so as lto deposit suchfsheets in stacksLsupport means on said base for pivotally supporting the receiving end4 of said frame,v the pivot axis of said frame being along said receivinglend and transverse' to said frame, said support means being swivelable about' an axis beneath and generally parallel with said pivot axis and said receiving end so` asto permit said frame to shift its position longitudinally during itsrnovement about said pivot axis; liftingrelements fulcrumed onfsaid base beneath said stacker frame land pivotally connected to saidlfranie for shifting said frame upwardly about said pivot axis'and longitudinally toward the stacking end while theframe is raised so as tocompensateoppositely forr the horizontal component of the arc of movement of the frameabout said pivot axis and maintain said upward movement of said stacker endon a'gene'rally perpendicular plane, operating means to turn said lifting elements about their respective `fulcrums so as to impart generally constant and uniform lifting force to lsaid liftingelements, and control devices actuated by the positioning of said frameto render said operating `rne`ans yoperativevfrom the lowermost position to the top position offsaid stacking frame and render said operating means ineitective at said top position so as to permit the frame to turn to its lowermost position. ,A Y t 2. InL a sheet stacker of `the character described, in combination, a basearstacker framehaving a receiving end and a stacking end and including a pluralityV of conveyors longitudinal ony said, frame tn car'ry sheets along said frameirom said receiving end to said stacking end so as to depositsuch sheets in stacks, support means on said base forfpivotally supporting the receiving end of ,said frame,the pivot axis of said frame being along said receiving :endend transverse to said frame, said supportmeans being A,swivelable abouean axis beneath and 'generally parallel withsaid pivot axis and said receiving end `so as to permit said frame Yto shift its position longitudinally during its moyement about said pivot axis; lifting Yelements f ulcrumed on said, base beneath said stacker frame `and pivotally connected to said frame for shiftingy said frame upwardly abouty said pivot` axis and longitudinally toward'the stacking end while the frameis raisedso as to `compensate oppositely for the horizontalk component of the arc` of movement ofthe frame about said pivot axis and maintain said upward movement of'said vstacker Yend .on a generally perpendicular, plane, operating means to `turn said lifting elementsfabontvtheir respective fulcrums soas toimpart generally constant and uniformlittingj'force to said lifting elementspand control devices actuated by the positioning ofsaidframefo render said operatingmeans operative from the lowermost'position tothe top positionof said stacking frame'andrender ysaid operating means ineffective t at 'said topposition so as to permit the frame Ato turn to its lowermost position, and a layboy frame pivotally supported on`said support means in registry with` said receivingend so as to shift longitudinally together with said stacker frame. i i 4 i,

3. In a 'sheet stacker of the character described, in combination, `a bfajseQa stacker iframe having a ,receiving end and a stacking end andrincluding a plurality of conveyors longitudinal on said frame to carry sheets along said trame from said receiving end to said stacking end lsolas to deposit suchisheets in stacks, support means on` said, for. pivotally supporting; the, receiving"endv of said trarne,` thepivot axis offssaid ,frame bemg along said 'receiving end and transverse .to said frame, said support means' being swivelable about an axis".beneath and, generally parallel with said pivot axis `and'said rel ceiving end so as to` permit said'frame to shift its lposition longitudinally during its movement aboutsaid pivot axis; lifting elements fulcrumed on said base beneath l said stacker'frame rand `pivotally connected to said fratrie for shifting said frame upwardly about said pivot vaxis and longitudinallyy (toward the stacking end WhiletheV frame is raised so as to'compensate oppositely for thel horizontal component of the 'arc of movement `of thev frariieabout said pivot axis and maintain-`said upward movement ofA said stacker end on a generally perpendicular plane, operating means to turn said liftingelement's about their respective fulcrums so as to'impart gen# erally constant and uniform lifting forcetosaid lifting'VA element'sfand control devices actuatedby the positioning" of said frame to render said operating means: operative fromthe lowermost position tothe top position of said',l

stacking frame and render said operating'mean's ineffective at said top position so as to permit the frame turn to itsilowermost position, and a layboy'frame piv-V otally supported on said: support means in regiistryvvitli` saidyreceiving "end so as to shift' longitudinally together with said stacker frame, and a device betweenlsid baseA and .said layboy `frame actuated by controlled,"pres'sureH medium lfor pivotally adjusting said layboy frarrieiaboilt n said supporty means into and out oftheway position and into registering operative position selectively; d

4. In"a"sheet'stacke'r of the character decribed'gili" combination, 'a base, Va stacker frame having" a receiv-f inged and a'stacking' end and Vincluding a plurality of conveyors longitudinal on said` yframe toV carryslieets/ along said frame from said receiving en'd to saidstaokin'g( end so as to deposit such sheets in stacks, supportme'ans on said base forpivotally supporting the yreceiving Vend., otsaid frame, the pivot axis of said frame being along y,

saidreceiving end :and transverse` to 'said frame,A said supportmeans being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its `position longitudinally yduring its movement about saidpivot axis;A lifting elements fulcrumed onysaid ,base beneath said stacker frame and pivotally connected to saidframe for shifting said frame yupwardlyabout said pivot axisV and longitudinally towardthe stacking end while the iframe is raised so as to compensate oppositely for the tion ofsaid stacking frame and-render said' operating means ineifective at said top position so as topermitthe frame to turn to its lowermost position, and a layboy` frame pivotally supported on said support means registry with said receiving end so as 'to shift longitudinally together with said stacker frame, and a pressure operated pivoted cylinder and piston connectiony between said base and said layboy frame for lifting said layboy frame into an out of the way position and lowering said layboyj frame into an operative registering position with Saidl receiving end at will, said layboy framel having' longitudinal conveyors thereon to carry sheet s to'said receiving end of said stacker frame.

5. In a sheet stacker of the'character described, in'y combination, a base, a stacker frame having a yreceiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame vfrom said receiving end to said stacking end so as to deposit such sheets in stacks, support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally iduring its movement about said pivot axis; lifting elements fulcrumed on said base beneath said stacker frame and pivotally connected to said frame for shifting said frame upwardly about said pivot axisand longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of the are of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to `turn said lifting elements about their respective fulcrums so as to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowerrnost position to the top position of said stacking frame and render said operating means ineffective at said top position so as to permit the frame to turn lto its llowermost position, and a layboy frame pivotally supported on said support means in registry with said receiving end so as to shift longitudinallyltogether with said stacker frame, and a pressure operated pivoted cylinder and piston connection between said base and said layboy frame for lifting said layboy frame into an out of the way position and lowering said layboy frame into an operative registering position with said receiving end at will, said layboy frame having longitudinal conveyors thereon to carry sheets 'to said re-` ceiving end of said stacker frame, and means to drive the conveyors on said stacker frame and on said layboy frame in synchronism. l

6. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets in stacks, support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as rto permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base beneath said stacker frame and pivotally connected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end While the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to turn said lifting elements about their respective fulcrums so as to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowerrnost position to the top position of -said stacking frame and render said operating means inelfective at said top position so as to permit the frame to turn to its lowermost position, said support means including a pair of spaced parallel arms, the lower ends of said arms being pivoted on said base and forming said pivot axis of said support means and the upper ends of said arms being pivoted to said receiving end of said stacker frame.

7. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets in stacks, support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base beneath said stacker frame and pivotally connected to said frame for shifti ing said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised so as` to compensate oppositely Ifor the horizontal component of the are of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to turn said lifting elements about their respective fulcrums so as to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated -by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said operating means ineffective at said top position so as to permit the frame to turn to its lowermost position, and a l-ayboy frame pivotally supported on said support means in registry with said receiving end so as to shift longitudinally together with said stacker frame, and a pressure operated pivoted cylinder and piston connection between said base `and said layboy frame for lifting said layboy frame into an out of the way position and lowering said layboy frame into an operative registering position with said receiving end. at will, said layboy frame having longitudinal conveyor-s thereon to carry-sheets to said receiving end of sa'id stacker frame, a conveyor drive shaft transverse at said receiving end for driving the conveyors on said stacker frame and on said layboy, s-aid support means including a pair of spaced parallel arms, the lower ends of said arms being pivoted on said base and forming said pivot axis of said support meafns and the upper ends of said arms being pivoted to said conveyor drive shaft, the receiving end of said stacker frame and said layboy frame being journalled on said conveyor drive shaft.

8. -In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including la plurality of conveyors longitudinal on said lframe to carry sheets along said frame vfrom said receiving end to said stacking end so as to deposit such sheets in stacks, `Support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis `and said receiving end so as to permit said l'frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on ysaid base beneath said stacker frame and pivotally connected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal cornponent of the arc of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to turn said lifting elements about their respective fulcrums so as to `impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame Y i 11 .4 and render said operating means ineffective at said top position soV toqpermit the frame to turn to its lowermost position, said lifting' elements comprising spaced parallel bell crank levers, means on said base for fulcruming said bell crank levers on an axis transverse with respect to said stacker frame and between'said base and said stacker frame, an arm of each bell crank lever being' pivoted tov said stacker frame and extending generally from said fulcrum toward said receiving end, and the other arm of eacn bell cranky lever being connected to said operating means for applying force about said fulcrum.

9. ln a sheet stacker of the character described, in combination, a base, a stacker frame having-a receiving end and a stacking end 'and-including a plurality of'conveyors longitudinal on said frame to carry sheets along said frame from saidreceiving end of said stacking end so as to deposit such sheets in stacks,.support means onsaid base for pivotally supporting the receiving end of said yframe, Athe pivot axis ofA said frame being along said receiving end and transverse to said frame, said support means being swivelable abou-t an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinallyduringits movement about said pivot axis; lifting elements fulcrumed on said base beneath said stacker frame and pivotally connected to said frame for shifting said frame upwardly about said pivot axis andlongitudinally toward the stacking end while'the frame is raised'so as to compensate oppositely for the horizontalvv component ofthe arc of`movement of the:v

frameabout'said pivot axis and maintain said upward movement of said stacker end on a generallyperpendicular, plane, operatingV means to turn said lifting elements about their respective fuicrums so as to impart generally constant and uniform lifting force to Vsaid lifting elements, and control devices actuated ,by the positioning of said frame to render said operating means operative from the lowermost position to the'top position of said stackingframe and render said operatingmeans ineffectiveA at said top position so as to permit the frame to turn to its lowermost position, saidV lifting `elernents comprising spaced parallel bell crank levers, means on said vbase for fulcruming said bell crank levers on an axis transverse with respect `to said stacker frame and betweenisaid base and said stacker frame, an arm of each bell crank lever being -pivoted to said stacker frame and extending generally from saidk fulcrum toward said receiving end, and the other arm of each bell crank lever being" connected to said operating means for applying force about said fulcrunr, the axes of *saidy fulcrums and of the pivoting of said armsof said bell crank levers being so `spaced from each other land from'the axis of the pivot'ofsaid receiving end that all said axes Vare sub-` stantialiy on the same general horizon-tal plane when the stacker frame is in horizontal positionf 10.,In a sheet stacker of the` character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end of saidstacking'end so as to deposit such sheets in stacks, support means von said basefor pivotally'supporting the receiving end of said frame, the pivot axis 'ofsaid frame being alongsaid receiving end and transverse to said frame, said support means being swivelable about an beneath and `gen`V erally parallel with said pivot axis and said receiving end so -as to permit said frame to shift its position longitudinally during its movement'aboutsaid pivotA axis; lifting elements yfulcrumed on said .base beneath said stacker frame andpivotally connected to saidfr'ame forf shifting,saidrameppwardw about Seid Pivot vzvxisand longitudinally toward. the .Stacking `end while thefframeis raised was, t0, compensate ,oppositely for the horizontal4 component of the are of movement of the frame about abbinati()i said-pivot and maintain said upward movement of said stacker -end on a generally perpendicular plane, operatingmeans to turn'said lifting elements about vtheir, respective.fulcrums' so as to impart generally. constant anduniform lifting force tosaidlifting elements, and controldevices actuated by the positioning of said frame to'lrender said operating means operative from the lower?, most position sto, the top .position of said stacking ,frame` v and render. said4 operating means ineffective at `saidftopj position so, as to permit the frame to turn to A itsV lowerfA most position, said lifting elementscomprising 'spaced parallel ybell i crank levers, y.means on said tbasewfor, ful-` crurning said bell crank leversV on an axis transverse.,withl respect to said stacker frame -andbetween said baseand, said stacker frame, an arm of each bell cranklever .being pivoted tosaid stackerframe and extendinggenerally, from said fulcriunltoward said receiving end, and the other p armtsfreeeh. bell Crank, lever being ,Cermectedw seid., Operating, means for applying force about" said intervint, the of saidrfnlcrums and ofthe pivoting of said arms, of. said bell crank levers being so spaced from each, otllieir andifrom the axis of the pivot of said receiving, end v thatfiall said -are substantiallyy ionuthe same gen- 1 yeral,horizontal plane'vvhen'thef stacker frame is inhori-.ll

zontal position,v saidioperating means including a "tran'sf` verseshaftfjour'nalled onA saidv baserbeneath the'n axis ,'of.' saidbellcrank'fulci'um and loffset, horizontallyfrom 'said' i fulcrurn toward the lreceiving end of thel stacker` iranieny a L.driveelement extended generally radially fromvlthe" shaft adjacentl to each bell crank, lenactingV generally'l horizontally spaced heads lon each drive elementand the adjacent"othery arm of the ycrank lever, fanarcuate'pef, riphery on each head, a flexible'pull line anchored atitsv opposite` ends tangentiailyon each pair of coacting cuate peripheries so` as to apply tangential pulling force andumotion'to ysaidliead'sat uniform peripheral speed" respectively, and'1 a driven, element extended generally i. radially/'from said shaft, a headon said `driven elementk having an arcuate periphery, a powered'ipuller device,l and aiiexible linetangentially anchored to the headiof saiddriven element and connected to said puller devicev` to exert a linealtangential puil on saidhead of said" driven element to turn all saidheads andl said bellcrank4 levers'at constant speed 'for elevating" rsaid stacker frame about its pivot.

l1 ln Ia sheet stackerofthe character described, in combination, `a base, a stacker frame having a receiving end `and a stacking end and including a plurality of con? `veyors longitudinal on said frame toA carry sheets along Lelements `,fuloruined on ,said base beneath said stackerl frame and pivotally connected to said frame kfor ,shifting saidl frame upwardlyabout saidpivot axis and ,longi-v. tudinally toward the stacking endV while the frame is, raised so as to compensate oppositely for the horizontal A component of thearc of movement .of the frame about saidpivot and maintain said upward movement of said stacker endlon a generally perpendicular plane, operating 1means to turny said lifting velements about theirV respective fulcruvmsso Aasto impart generally constantyaiidnniform lifting forcefto said lifting elements, and

' control devices actuatedby the positioning of said frame to v render saidoperating lmeans operativefromthev lov/er#` moet Pe-Stien,t9thsteupositon 0f aidgetackise flame and. render .Seid @erstma means .ineffective ai Said 19pv .t

most position, said lifting elements comprising spaced parallel bell crank levers, means on said base for fulcruming said bell crank levers on an axis transverse with respect to said stacker frame and between said base and said stacker frame, an arm of each bell crank lever being pivoted to said stacker frame and extending generally from said fulcrum toward said receiving end, and the other arm of each bell crank lever being connected to said operating means for applying force about said fulcrum, the axes of said fulcrums and of the pivoting of said arms of said bell crank levers being so spaced from each other and from the axis of the pivot of said receiving end that all said axes are substantially on the same general horizontal plane when the stacker frame is in horizontal position, said operating means including a transverse shaft journalled on said base beneath the axis of said bell crank fulcrum and offset horizontally from said fulcrum toward the receiving end of the stacker frame, a drive element extended geenrally radially from the shaft adjacent to each bell crank, coacting generally horizontally spaced heads `on each drive element and the adjacent other arm of the crank lever, an arcuate periphery on each head, a flexible pull line anchored at its opposite ends tangentially on each pair of coacting arcuate peripheries so as to apply tangential pulling force and motion to said heads at uniform peripheral speed respectively, and a driven element extended generally radially from said shaft, a head on said driven element having an arcuate periphery, a powered puller device, and a flexible line tangentially anchored to the head of said driven element and connected to said puller device to exert a lineal tangential pull on said head of said driven element to turn all said heads and said bell crank levers at constant speed for elevating said stacker frame about its pivot, each of said arcuate peripheries of said heads including a series of teeth and said flexible lines being chains yanchored on the respective heads so as to constantly apply tangential lineal pull on the respective coacting heads.

12. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end of said stacking end so as to deposit such sheets in stacks, support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being `along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base beneath said stacker frame and pivotally yconnected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised s as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain such upward movement of said stacker end on a generally perpendicular plane, operating means to turn said lifting elements about their respective fulcrums so as to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said operating means inetfective at said top position so as to permit the frame to turn to its lowermost position, said lifting elements comprising spaced parallel bell crank levers, means on said base for fulcruming said bell crank levers on an axis transverse with respect to said stacker frame rand between said base and said stacker frame, an arm of each bell crank lever being pivoted to said stacker frame and extending generally from said fulcrum toward said receiving end, and `the other arm of each bell crank lever being connected to said operating means for applying force about said fulcrum, the axes of said fulcrums and of the pivoting of said arms of said bell crank levers being so spaced from each other and from the axis of the pivot of said receiving end that yall said axes are substantially on the same general horizontal plane when the stacker frame is in horizontal position, said operating means including a transverse shaft journalled on said base beneath the axis of said bell crank fulcrum and offset horizontally from said fulcrum toward the receiving end of the stacker frame, a drive element extended generally radially from the shaft adjacent to each bell crank,

coac-ting generally horizontally spaced heads on each drive element and the adjacent other arm of the crank lever; an arcuate periphery on each head, a ilexible pull line anchored at its opposite ends tangentially on each pair ot coacting arcuate peripheries so as to apply tangential pullt ing force and motion `to said heads at uniform peripheral speed respectively, and a driven element extended gent ing a cylinder pivoted on said base, a plunger working in` said cylinder, a plunger rod extended from said plunger, said flexible line from said driven element being connected -to said plunger, and means to introduce a pressure medium into said cylinder to move said plunger away from said driven element thereby to pull said flexible line of said driven element for turning said transverse shaft.

13. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end of said stacking end so as to deposit such sheets in stacks, `support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about van axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base and pivotally connected lto said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stackl ing end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain such upward movement of said stacker end on a generally perpendicular plane, operating means to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said operating means ineffective at said top position so as to permit the frame to turn to its lowermost position, said lifting elements comprising spaced parallel bell crank levers, means on said base for fulcruming said bell crank levers on an axis transverse with` respect to said stacker frame and between said base and said stacker frame, an arm of each bell crank lever being pivoted to said stacker frame and extending generally from said fulcrum toward said receiving end, and the other arm of each bell crank lever being connected to said operating means for applying force about said fulcrum, the axes of said fulcrums and of the pivoting of said arms of said bell crank levers being so spaced from each other and from the axis of the pivot of said receiving end that all said axes `are substantially on the same general horizontal plane when the stacker frame is in horizontal'position, said operating means including a transverse shaft journalled on said ybase beneath the axis of saidk bell crankfulcrum and offset horizontally from said fulcrum toward the receiving'end of the stacker frame, a drive head,fa exible p`ul1 lineanchored at its opposite endsV tangentially'l on each pair of coactingfarcuate peripheries so as to apply 'tangential pulling forceand motion to said heads Yatl uniform .peripheral speed respectively, and a driven element extended generally radially from said shaft, a head on said driven element having an arcuate periphery, a poweredpuller device, and a flexible line tangential/ly anchored to the head of said dniven element and connected to said puller device to exert a lineal tangentiall pull on saidhead of said driven element'to turn all said heads and said bellV crank llevers at constantspeed for elevating said stacker frame about its pivot, said powered puller device including `a cylinder pivoted on said base,P a plunger workinfg'in lsaid cylinder, a'plunger rod extended'from said plunger, said flexibleline from said drivenelement `beingconnected` toesai'd plunger, and means t o introduce a pressure'mediurn into said cylinder to move said Vplunger-away from said driven element therebylto` pull`said ilexible line of said driven element for `turning said transverse shaft, vsaid control devices in,- cluding' valvesfto control'the flow of said pressure medium to said cylinder, electro-magnetic devices to control saidl valves, cam actuated switches in the circuit of said electromagnetic devices, and cams on said shaft to actua'te said switchesV in the respective extreme positions of said stacker frame so as to open said valves at the lofwermo'ststacker position `to v,convey ythe pressure medium into saidcylirider forelevating'said stacker frame from its,V lowermost to, itsY highest Aposition land Ito ylay-pass saidv pressure medium from said cylinder to permit theireturn of said i-sltacker frame toY its lovver'most position.

14.4 In a sheet stacker of the character deseribed, in combination, abase,v afst'ackerV frame having a receiving endV and astackigfend andfinc'lu'ding a plurality of conveyors Clongitudinal on said frame to carry sheets along said framefroinsaidreeeiving end of said stacking lend so as todep'osit 'suchfsheets in stacks, support means'on said basefor pivotally' supporting thereceiving endY of sai-d frame, :thepivot axis of said frame being along said receiving end 'and transverse'to said frame, said ysupport meansbei'ng"swivelablel about an axis beneath and generally' prallelwith said pivot axis andsaid receiving end so as to permit said lframeto shift its position longitudinally' duringmits" movernent'about said pivot axis; lifting elernventsfulcrumed on said basevand pivotally connected to s ai'dfrarne for shiftingsaidfrarne upwardlyabout said pivot-axis '-andlongitudinally toward the stacking end while the yfratrie israised so as to compensate oppositely forthehori'zontal Vcomponent of the arc of movement of thejframe about said pivot axis' and maintain such upward movement of vsaid'stacker yend on ,a generally perpendicular plane, operating means to impart generally constarith andi'uniform lifting force to said lifting elements, and control devices actuated'bythe positioning of said frame to render 4said operating-means operative from the lowermost positionto the topposition of said stacking frame andrerider said operating means ineffective -at said topfposition so' a's'to permit the frame to turn'to its loweririostgpositionfsaid lifting elements comprising spaced parallel bell crank levers, means on said base for fulcrrningfsaidbell crank levers on an axis transverse with respect to said stacker frame and between said base and saifdst'ac'kerl frame, anarm of each bell crank lever being pivotedfto said stacker frame and xtending generally fromsaid viulcr'um ltoward said receiving'end, and the other arm of each bell crank lever being connected to said opn era'ting means for applying force about said fulcruin, the axes of said fulcrums and of the pivoting of said arms of said bell crank levers being so spaced frornieach other and from the axis of the pivot of said receiving end that ally said axes are substantially on the same general -horizontal plane when the stacker frame is in horizontal position, said operating means includingY a transverse shaft journalled on said base beneath the axis of said bell crank ulcrum andv offset horizontaily from said fulcrum toward the receiving end of the stacker frameLa drive element extended generally radially from the shaftadjacentto each bell crank, coacting generally horizontally spaced heads on each drive element and the adjacent other arm of the crank lever, an arcuate periphery on each head, a iiexible pullline anchored atits opposite ends tangentially on each pair of coacting arcuate peripheries so as to apply tangential pulling force and motion to said heads atuniform peripheral speed respectively, and adriven element extended generally radially from said shaft, a head on an arcuate periphery,

said driven element having a powered puller device, and a viiexible line tangentially anchored to the headv of said driven element and,y connected to said puller device to exert a lineal tangential l pull on said head of said driven element to turn allsaid heads `and said bell crank levers at constant speed for elevating said stacker frame about its pivot, said powered puller device including a cylinder pivoted on said base, a plunger working in said cylinder, a plunger rod extended from said plunger, said ilexible line from saidy driven element being connected to said plunger, and means to introduce a pressure medium into sald cylinder tomove said plunger away from said driven element thereby to pull said flexible line of said driven element for turning said transverse shaft, said control devices including valves to control the flow of said pressuremediuin medium from said cylinder to permit the return of, said stacker frame to its lowermost position, and electromagnetic devices actuated by the cams at the highest position of said stacker frame to hold said valves in by-passing position until said stacker frame returned :to said lowermosty position. 1 t

l5, ln a sheet stacker of the character described, in

combination, a base, a stacker frame having areceivingV end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets in stacks, support means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; `lifting elements fulcrumed on said base and pivotally connected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking 'end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative `from the lowermost position to the top position of said stacking frame most position, and sheet obstructing devices near the stacker end of said stacker frame normally below the level of said conveyors, electrically actuated means to raise said obstructing devices above the level of said conveyors to retard the travel of sheets on said conveyors, a cam actuated switch for said electrically actuated means, said control device including a cam to operate said switch to actuate said means for keeping said obstructing devices in raised position during the return of said stacker from its uppermost elevated position to its lowest position.

16. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end of said stacking end so as to deposit such sheets in stacks, support means on said base of pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base and pivotally connected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain such upward movement of said stacker end on a generally perpendicular plane, operating means to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said operating means ineffective at said top position so as to permit the frame to turn to its lowermost position, said lifting ele-ments comprising spaced lparallel bell crank levers, means on said base for fulcrurning said bell crank levers on an axis transverse with respect to said stacker frame and between said base and said stacker frame, an arm of each bell crank lever being pivoted to said stacker frame and extending generally from said fulcrum toward said receiving end, and the other arm of each bell crank lever being connected to said operating means for applying force about said fulcrum, the axes of said fulcrums and of the pivoting of said arms of said bell crank levers being so spaced from each other and from the axis of the pivot of said receiving end, that all said axes are substantially on the same general horizontal plane when the stacker frame is in horizontal position, said operating means including a transverse shaft journalled on said base beneath the axis of said bell crank fulcrum and offset horizontally from said fulcrum toward the receiving end of the stacker frame, a drive element extended generally radially from the shaft adjacent to each bell crank, coacting generally horizontally spaced heads on each drive element and the adjacent other arm of the crank lever; an arcuate periphery on each head, a flexible pull line anchored at its opposite ends tangentially on each pair of coacting arcuate peripheries so as to apply tangential pulling force and motion to said heads at uniform peripheral speed respectively, and a driven element extended generally radially from said shaft, a head on said driven element having an arcuate periphery, a powered puller device, and a flexible line tangentially anchored to the head of said driven element and connected to said puller device to exert a lineal tangential pull on said head of said driven element to turn all said heads and said bell crank levers at constant speed for elevating said stacker frame about its pivot, said powered puller device including a cylinder pivoted on said base, a plunger working in said cylinder, a plunger rod extended from said plunger, said flexible line from said driven element being `connected to said plunger, and means to introduce a pressure medium into said cylinder to move said plungerY away from said driven element thereby to pull said iexible line of said driven element for turning said transverse shaft, a sheet obstructing element adjacent each conveyor yieldably held out of the way of said sheets, electromagnetic actuator device to raise said sheet obstructing elements into sheet retarding position above the level of said conveyors; said control devices including valves to control the flow of pressure medium to said cylinder, electromagnetic devices to control said valves, cam actuated switches in the circuit of said electromagnetic devices, and cams on said shaft to actua'te the respective electromagnetic devices in the respective extreme positions of said stacker frame so as to raise said obstructing element and by-pass said pressure medium from the highermost elevated position of said stacker to' its lowermost position, and to close said by-pass and release said obstructing element in said lowermost position of the stacker.

i7. ln a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets in stacks, support means on said base for pivotally supporting thereceiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base and pivotally connected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to impart generally constant and uniform lifting force to said lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said operating means ineffective at saidtop position so as to permit the frame to turn to its lowermost position, and a layboy frame pivotally supported on said support means in registry with said receiving end so as to shift longitudinally together with said stacker frame, and a pressure operated pivoted cylinder and piston connection between said base and said layboy `frame for lifting said layboy frame into an out of the Way position and lowering said layboy frame into an operative registering position with said receiving end at will, said layboy frame having longitudinal conveyors thereon to carry sheets to said receiving end of said stacker frame, a conveyor drive shaft transverse at said receiving end for driving the conveyors on said stacker frame and on said layboy, said support means including a pair of spaced parallel arms, the lower ends of said arms being pivoted on said base and forming said pivot axis of said support means and the upper ends of said arms being pivoted to said conveyor drive shaft, the receiving end of said stacker frame and said layboy frame being journalled onsaid conveyor drive shaft, said conveyors on said layboy being driven by said conveyor drive shaft and power means to constantly rotate said drive shaft.

18. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of conveyors longitudinal on said frame to carry sheets along said frame from said receiving end of saidstacking end so as to deposit such sheets in stacks, `support `means on said base for pivotally supporting the receiving end of said frame, the pivot axis of said frame bei9 ing along said receiving end and transverse Vto said frame, saidgsupport means being swivelable about an axis beneath andV generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base and pivotally connected tosaid frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of thegarc of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generallyperpendicular plane, operating means to impartgenerally constant and uniform lifting force to said, lifting elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and rendersaid operating means ineffective at said top position so as to permit the `frame to turn to its lowermost position, said liftingr elements comprising spaced parallel bell crank levers, means on said base for fulcruming said bell crank levers on an axis transverse with respect to said stacker frame and between said base and said stacker frame, an arm of each bell crank lever being pivoted to said stacker frame and extending generally from said fulcrum toward said receiving end, and the other arm of each bell crank lever being connected to said operating means for applying force about said fulcrum, the axes of said fulcrums and of the pivoting of said arms of said bell crank levers being so spaced from each other and from the axis of the pivot of said receiving end that all said axes are substantially on the same general horizontal plane when the stacker frame is in horizontal position, said operating means including a transverse shaft journalled on said base beneath the axis of said bell crank fulcrum and offset from said fulcrum toward the receiving end of said stacker frame, a sector shaped arm on said shaft adjacent each bell crank lever, the adjacent other arm of each bell crank lever being also generally sector shaped, the arcuate peripheries of adjacent sector shaped arms being offset generally in the same plane, a flexible pull line being anchored on each pair of adjacent sector peripheries to exert a generally straight lineal pull on said peripheries generally on the line of a tangent common to said adjacent sector peripheries, a third sector shaped arm `on said shaft, a powered puller device, and a flexible line extended from said puller device and anchored to the periphery of said third sector shaped arm generally tangentially and horizontally with respect to the periphery f said sector.

19. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end and including a plurality of con- `veyors longitudinal on said frame to carry sheets along said frame from said receiving end of said stacking end soas to deposit such sheets in stacks, support means on saidbase for pivotally supporting the receiving end of said frame, the pivot axis of said frame being along said receiving end and transverse to said frame, said support means being swivelable about an axis beneath and generally parallel with said pivot axis and said receiving end so as to permit said frame to shift its position longitudinally during its movement about said pivot axis; lifting elements fulcrumed on said base and pivotally connected to said frame for shifting said frame upwardly about said pivot axis and longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said pivot axis and maintain said upward movement of said stacker end on a generally perpendicular plane, operating means to impart generally constant and uniform lifting force to said lift- Alng elements, and control devices actuated by the positioning of said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said Operating means ineffective. at said topposition so as `to` permit the frame' to turn to its lowermost position, said lifting` elements comprising spaced parallel bell crank levers, means on said basey for fulcruming said bell crank levers on an axis transverse with respect to said stacker frame and;

between said base and said stacker frame, an arm of each bell crank lever being pivoted to said stacker frame and extending generally from said fulcrum toward said receiving end, and the other arm of each bell crank lever stantially on the same general horizontal plane when theV stacker frame is in horizontal position, said operating means including a transverse shaft journalled on said base beneath the axis of said bell crank fulcrum and offset from said fulcrum toward the receiving end of said stacker frame, a sector shaped arm on said shaft adjacent each bell crank lever, the adjacent other arm of each bell crank lever being also generally sector shaped, the arcuate peripheries of adjacent sector shaped arms being offset generally in the same plane, a flexible pull line being anchored on each pair of adjacent sector peripheries to exert a generally straight lineal pull on said peripheries generally on the line of a tangent common to said 'adjacent sector peripheries, a third sector shaped arm on said shaft, a powered puller device, and a flexible line extended from said puller device and anchored to the periphery of said third sector shaped arm generally tangentially and horizontally with respect to the periphery of said sector, sprocket teeth on the periphery of each of said sector shaped arms, and said flexible lines consisting of sprocket chains engaging the respective teeth.

2 0. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end, conveyor means longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets on a stack at said stacking end, swiveling supports extended from said base to the receiving end of said stacker frame, a conveyor drive shaft of said conveyor means being journalled on the top of said swivelling supports so as to form the fulcrum for the raising and lowering of said stacker frame about the axis of said shaft, lifting levers fulcrumed on said base beneath said stacker frame, each lifting lever being extended toward said receiving end and being pivoted to said stacker frame between said shaft and the fulcrum of said lifting levers so that the turning of said levers shall move the same stacker frame about the axis of said shaft pivotally and also longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said shaft axis and maintain the upward movement of said stacker end on a generally perpendicular plane, operating means on said base connected to said levers for turning said lifting levers about their respective fulcrums by a generally constant and uniform lifting force, and control devices actuated by said frame to render said operating means operative from the lowermost position to the top position of said stacking frame and render said operative means ineffective at said top position so as to permit the frame to return to its lowermost position.

2l. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end, conveyor means longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets on a stackat said stacking end, swiveling supports extended from said base to the receiving end of said stacker frame, a conveyor drive shaft of said conveyor means being journalled on the top of said swiveling supports so as to form the fulcrum for the raising and lowering of said stacker frame about the axis of said shaft, lifting levers fulcrumed on said base beneath said stacker frame, each lifting lever being extended toward said receiving end and being pivoted to said stacker frame between said shaft and the fulcrum of said lifting levers so that the turning of said levers shall move the said stacker frame about the axis of said shaft pivotally and also longitudinally toward the stacking end while the frame is raised so as to compensate oppositely for the horizontal component of the arc of movement of the frame about said shaft axis and maintain the upward movement of said stacker end on a generally perpendicular plane, an arm extended from the fulcrum of each lever, an arcuate engagement member on each arm, a base shaft on the base transverse to said base and beneath said frame, a generally segmental crank arm on said base shaft, a flexible line connecting said segmental arm with said arcuate engagement member for transmitting movement from one to another, and means to apply a constant turning to the base shaft and to said segmental arms for raising said stacker frame.

22. In a sheet stacker of the character described, in combination, a base, a stacker frame having a receiving end and a stacking end, conveyor means longitudinal on said frame to carry sheets along said frame from said receiving end to said stacking end so as to deposit such sheets on a stack at said stacking end, swiveling supports extended from said base to the receiving end of said stacker frame, a conveyor drive shaft of said conveyor means being journaled on the top of said swiveling supports so as to form the fulcrum for the raising and lowering of said stacker frame about the axis of said shaft, lifting levers fulcrumed on said base beneath said stacker frame, each lifting lever being extended toward said receiving end and being pivoted to said stacker frame between said shaft and the fulcrum of said lifting levers so that the turning of said levers shall move the said stacker frame about the axis of said shaft pivotally and also longitudinally toward the stacking end while the frame is raised so as to compensate olppositely for the horizontal component of the arc 0f movement of the frame about said shaft axis and maintain the upward movement of said stacker end on a `generally perpendicular plane, an arm extended from the fulcrum of each lever, an arcuate engagement member on each arm, a base shaft on the base transverse to said base and beneath said frame, a generally segmental crank arm on said base shaft, a flexible line connecting said segmental arm with said arcuate engagement member for transmitting movement from one to another, and means to apply a constant turning to the base shaft and to said segmental arms for raising said stacker frame, and a layboy, a conveyor on the layboy being driven by said conveyor shaft and being supported on said conveyor shaft in alignment with the receiving end of said stacker frame, and means to selectively adjust the angular position of said layboy about said conveyor shaft.

References Cited in the le of this patent UNITED STATES PATENTS 2,660,432 Wilske et al. NOV. 24, 1953

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