US2726013A

US2726013A - Apparatus for dispensing slats

Info

Publication number: US2726013A
Application number: US201556A
Authority: US
Inventors: Richard L Rice; David G Kingsley; Glen P Woodbury
Original assignee: Stapling Machines Co LLC
Current assignee: Stapling Machines Co LLC
Priority date: 1950-12-19
Filing date: 1950-12-19
Publication date: 1955-12-06
Anticipated expiration: 1972-12-06

Description

Dec- 6, 1955 R. l.. RICE Erm.

APPARATUS FOR DISPENSING SLATS '7 Sheets-Sheet 1 Filed Dec. 19, 1950 HUM )jjffwkux E QW nh A wb wn Si E A o nl, NQ w NS mm bv vw my R Dec 6 1955 R. L. RICE ETAL 2,726,013

APPARATUS FOR DISPENSING SLATS Filed Dec. 19, 1950 7 Sheets-Sheet 2 Il ll i l l ma, am #4 Afro/P Ys.

Dec. 6, 1955 R. L. RICE ET AL.

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www c/Qk Ewk @5TM Smm *SEL Nm QNX- /Nmx wm\ NWN: MV/MN NTE j .J QN rf 11 (6x Dec- 6, 1955 R. L. RICE ETAL APPARATUS FORl DISPENSING SLATS 7 Sheets-Sheet '7 Filed Dec. 19, 1950 United States Patent() APPARATUS FOR vDESPENSING SLATS Richard L. Rice, Madison, and David G. Kingsley, Mountain Lakes, N. J., and Gien P. Woodbury, Reading, Mass., assignors to Stapling Machines Co., Rockaway, N. J., a corporation of Delaware Application December 19,1950, Serial No. 201,556

4 claims. (Cl. z2113) This invention relates to apparatus for feeding thin side material or slats to box and crate making machines, for example, wirebound box and crate making machines of the type disclosed in U. S. Patents Nos. 2,304,510 and 2,482,370.

In such machines, a pair of parallel conveyor ,bands carry properly arranged box parts past a transverse row of stapling units where the box parts are stapled together to form box-part units or complete box blanks. The conveyor bands are normally provided with space blocks which engage the box parts and move them -in properly spaced relationship. Heretofore, the slats have been customarily placed in position on the conveyor bandsmanually by one or more operators or so-called slat layers who stand near the input end of the box-partmaking machine and take the slats from large stock piles at either side of the machine. Although the space blocks onthe conveyor bands assist to some extent the proper positioning of the slats on the rapidly moving conveyor bands, the manual placement of slats requires considerable skill, dexterity and experience on the partof the operators.

At the rates of machine speed now customarily used in the wirebound box and crate making industry, each machine requires two or more persons to lay the slatsand another person to replenish the stock piles. ,Should the machine speeds be further increased, the laying of slats would require even more personnel, .so that suchincreases in speed will not enable any appreciable reduction in the cost of manufacture of boxes and crates.

The present ,invention overcomes these limitations 4and enables substantial reduction in manufacturing costs by providing a practical apparatus for accurately and dependably placing slats in vposition on the conveyor bands of a wirebound box or crate manufacturing machineoperating at high rates of speed.

The invention provides a reservoir or `hopper for holding a generally vertical stack of slats, having a pairtof lower supporting members on which the stack rests. An auxiliary conveyor comprising a pair of endless roller'chains is provided, having lslat-.engaging elementsarranged ,in parallel pairs, eachpair adapted ,simultaneously to engage the bottom slat in the stack at spaced points, strip the slat from the bottom of the stack and deposit it kupon the conveyor bands of the Vbox making machine. The slat-engaging elements are .adjustable to various positions along the auxiliary conveyor chains in accordance'withthe desired pattern of slats `in the box-part unitbeing made. Means are provided for initiating movement-of the auxiliary conveyor chains simultaneously with the arrival at the apparatus of the leading space block of a box-.part unit, and for stopping movement of the chainsafter one complete cycle or revolution thereof.

Exit gates are provided to prevent the normal passage 2,726,013 Patented Dec. 6, 1955 lce l withoutoverloading the mechanism which drives the auxiliary conveyorchains or jamming'one or more slats between the ,moving auxiliary conveyor and some stationary part of ,the apparatus. This hinged .gate assembly is mounted on a pivoted link which allows it to swing freely upward and prevents .the exertion by the gate of any substantial pressure vertically downward on the slats passing therebelow, to prevent scoring of the slats and possible overloading or jamming.

The supporting members at the bottom of the hopper are spaced inboard of the ,auxiliary conveyor chains so that, even though, due to some deformity, the bottom slat engages onlyfone of the .supporting members, or engages one of the supporting members with greater friction than the other, the two slat-,engaging members will engage the slat at Opposite sides ofthe supportingmember constituting the point of greatest friction, thereby tending to feed the slat from thehopper. correctly,lrather than producing a couple which would rotate the slat and initiate a tanning of successive slats with possible jamming. For the samereason, the ,two exit gates are also positioned inboard of the auxiliary conveyor chains.

The hopper is provided with vertical guide members which engage the stack of slats at its rear corners, so that when a slaty is engaged by an engaging element on only one of the auxiliary conveyor chains, it will pivot about the verticalguide member at its opposite corner, moving the slat forwardly along its entire length and allowing both of the next Apair of engaging elements on the conveyor chains to engage the next slat above and feed it correctly from the hopper.

ln the drawings:

' Figure l is a fragmentary side elevational-view of a wirebound box and crate making machine, including apparatus for dispensing slats, which embodies featuresof the present invention;

Figure 2 is a fragmentary side elevational view atenlarged scale of the slat-dispensing apparatus shown in Eigure 1;

`Figure 3 is a fragmentaryfront elevational'view of the apparatus;

Figure 4 is an enlarged fragmentary sectional view taken generally along the line 4 4 of Figure 3;

Figure 5 is a top plan view of the portion of the machine shownin'l-Tigure 4;

Figure 6 is a fragmentary sectional View taken generally along thelines` 6--6 in Figure 2;

Figure 7 `is .an enlarged vperspective View of one of the slat-engaging members .carried by the auxiliary Aconveyor chains;

-Figure 8l is an enlarged sectional view taken vgenerally along the line of 8-8 ofFigure 2;

Figures 9A, 9B and 9C are fragmentary side elevational views of one of the'primary gate assemblies, showing its successive movements vto allow van abnormally thick slat to pass from the hopper;

Fig-ure 10 is a hschematic Vdiagram showing the electrical circuit for controlling the rdrive to the auxiliary conveyor chains;

vFigures 11A, 11B and 11C are diagrammatic bottom views of thehopper of a dispensing apparatus of the type previously used, showing successive steps in the feeding of `slats thereby land illustrating one defect of such prior apparatus;

.Figures 12A, 12B and 12C,are similar views illustrating another defect of :the priorapparatus; and

Figures 13A, `13B and 113C are similar-views illustrating ythe elimination of lthis defect by the apparatus of the present invention.

As may be seen in Figure 1the slat dispensing apparatus, generally designated A, isdisposed near the input end of a box or crate making machine, the central or stapling portion of which is shown at B. As is customary in such machines, a main conveyor comprising a pair of parallel conveyor bands C (Figure 6) is employed for carrying properly arranged box parts past a transverse row of stapling units in the central section B, where they are stapled together to form box-part units or complete box blanks. The conveyor bands C are supported upon parallel rails 20 (Figures 1 and 6) which extend the length of the machine. The conveyor bands are provided with space blocks D having upstanding push tins F to engage the slats, and certain of the space blocks are additionally provided with outwardly extending ns which engage the cleats G to which the slats are to be stapled. The slats rest upon the tops of the cleats, the cleats in turn riding upon outboard tracks H. The position of the space blocks is adjustable along the conveyor bands in accordance with the desired pattern of slats and cleats in the box-part units being made.

The slat dispensing apparatus A is mounted above and transversely of conveyor bands C, being secured to and supported by the rails 20.

As may be seen particularly in Figures l, 2 and 3, the slat dispensing apparatus comprises a hopper or trough 22 adapted to hold a generally vertical stack of slats 24. The hopper 22 is formed of vertical angle guides 26 at the rear left and right corners of the stack of slats, a wall member 2S at the right-hand side of the stack, as viewed in Figure 3, and a pair of spaced, bent guide members 30 at the front of the stack. The lower ends of the angle guides 26 are secured to ange-based mem bers 32 which are supported on brackets 34 attached to the outside of the rails 20, and are slotted to allow the angle guides 26 to be moved longitudinally of the machine to accommodate dilerent widths of slats. Each end of the hopper is supported upon one of the rails 20 so that movement of the rails to vary the spacing of the conveyor bands C also varies the width of the hopper and allows it to accommodate slats of any desired length.

The inclined portions of the bent guides 30 form a stable and easily accessible reservoir for slats. The angle guides 26 extend above the vertical portion of the stack but terminate below the top of the stack to permit the easy placement of slats against the inclined portions of the guides 30.

As shown in Figures 3 and 6, the stack of slats rests upon a pair of spaced horizontal supports 50, which are supported upon and extend upwardly from brackets 52 secured to the inside of the longitudinal rails 20. The height of the supports 50 is such that the bottom slat of the stack is supported slightly above the level of the tops of the push ns F on the space blocks D, so that the push tins may pass freely beneath the stack of slats.

The slats are individually and successively removed from the bottom of the stack by means ofslat-engaging elements 54 (Figure 2) on a pair of auxiliary conveyor chains 56. Each of the auxiliary conveyor chains 56 is trained upon a pair of

idler sprockets

58 and 60, and one of the chains is additionally trained upon a driving sprocket 62. In order that the two auxiliary conveyor chains may be driven in synchronism, the two idler sprockets 58 are secured upon a common shaft 64, the ends of which are journalled in bearings 66 (Figure 6) supported on the inner brackets 52. The two idler sprockets 60 are mounted upon individual stud shafts 67 (Figure 2), which are positioned at diierent distances from their respective idler sprockets 58, as may be seen in Figure 2, to allow one of the chains to be trained upon the drive sprocket 62. The stud shafts 67 are each secured between a vertically spaced pair of rails 68 (Figures 2 and 3) which extend longitudinally of the machine to allow adjustment of the positions of the idler sprockets 60 to accommodate different lengths of chains.

As shown in Figure 7, each of the Slat-engaging elements 54 is formed of a single piece of metal with a pair of hook portions 54a at its leading end, which are adapted to clip-fasten about the rounded leading ends of the outer links of auxiliary conveyor chain 56 to secure the slatengaging element in position on the chain. At the after end of the Slat-engaging element, an upstanding ange 54b is provided for engaging the edges of the slats. The height of this ange 54b is just less than the thickness of the slats being dispensed by the apparatus, so that the Slat-engaging element will positively engage the bottom Slat of the stack without touching the next slat above. The Slat-engaging elements are mounted in parallel pairs, one on each of the chains 56, so that as the chains are driven in synchronism, the bottom slat of the stack is engaged simultaneously by two of the Slat-engaging elements and pushed from the stack correctly oriented, that is, with the long axis of the slat perpendicular to its direction of movement. After each slat is picked up by the Slat-engaging elements, it is carried with the chains to the point where the path of the chains curves downwardly around the idler sprockets 58. There the slat cannot follow the downward path of the chains, because the ends of the slat overhand the cleats G at either side, as shown in Figure 6, so that the slat is deposited on the top of the cleats and moves with them as they are driven by the conveyor bands C. As the conveyor bands move forward with a slight jostling action, the slats tend to slip along the tops of the cleats until they Contact the push ns F on the space blocks D, where they are positively engaged in the correct position for stapling relative to thc cleats G.

The Slat-engaging elements 54 are so positioned along the auxiliary conveyor chains 56 as to place the slats upon the cleats at or just in advance of the push fins F.

' The removability of the Slat-engaging elements 54 from the links of the chain allows their positions to he changed to accord with the pattern of slats in the boxes or crates being made. In order to allow variation of the position of the ange 5411 with respect to the leading ends of the links of the chains 56, the overall length of the slatengaging element may be varied. Several sets of slatengaging elements, having different lengths, are provided for this purpose.

In order to support the auxiliary conveyor chains 56 and to urge the Slat-engaging elements 54 upwardly to ensure their positive engagement with the bottom slat in the stack, under the upper span of each of the auxiliary conveyor chains 56 at the point where the slatengaging elements 54 contact the rear edges of the slats, there is provided, as shown in Figures 4 and 5, n spring loaded support or track 124 which is adapted to engage the under side of the upper span of the auxiliary conveyor chain 56. Each of the tracks 124 is mounted upon a cylindrical plunger 126 which extends downwardly into a cylindrical recess 128g in a supporting block 128. The plunger 126 has at its lower end an extension of reduced diameter 126a which. projects through an opening 128b in the bottom of the supporting block 128. A coil spring 130 compressed between the upper portion of the plunger 126 and the bottom of the recess 128:1 urges the plunger 126 and track 124 upwardly to ensure positive engagement of the flanges 54b of the Slat-engaging elements with the rear edges of the slats. A retaining ring 132 around the lower end of the extension 126g limits upward movement of the plunger 126 and prevents ejection of the plunger from the supporting block when the chains 56 are removed.

The auxiliary conveyor chains are arranged to be driven intermittently, being started simultaneously with the arrival at the slat dispensing apparatus of the leading space block of a box-part unit, and being stopped after one cycle or revolution and restarted for the next box-part unit and so on. To this end, an electrically controlled clutch 70 (Figure 3) and an electrically controlled brake 72 are provided in conjunction with the avreste S drive sprocket' 62 f through driven. v

The sprocket 62 is-fixedf uponthe central'portion of a sleeve 74 which is rotatablyl suppcrtedon ay fixed shaft 76 and which bears at itsl opposite-ends the disc 70a of clutch 70 and the disc-72al brake-72;

The hollow body portion 7tlb offthe= clutch, which contains a magnetic coil, is also rotatably mounted upon the shaft 76 adjacent the disc 7061-; the clutch body 70b is formed at one end of an extended hub 70e, at the opposite end of which is` fixed a-mitergea.r Stb; This gear 80 is connected to be driven by a drive shaft 82 in the central portion ofthe machine (see Figurel lt) through the meshing miter gear 84;. shaftl 86, miter gears 88 and 96, sprocket 92, chain 94v and sprocket 96. Thus,V the clutch body '7Gb (Figure 3) is driven continually and rotates freely upon the-shaft 76. inergization of the magnetic coil within the clutch body 70b attracts the disc 76a and causes it to engagethe-clutch body 7Gb and rotate with it, thereby driving..v the sprocket 62 and the auxiliary conveyor chains 561 The magnetic coil in the continuously rotating clutch body 7lb is supplied electrical current through a pair ofcollector rings 70d on the hub 7lc of the clutch, the collector ringsbeing conductively engaged by flexible Contact fingers or brushes 1% mounted upon an insulating blockl 1611 (see Figures 2 and 6).

The main body portion 72b of the brake 72 is mounted upon the stationary shaft 76 adjacent brake disc 72a and is rendered non-rotative by attachment tol the frame of the apparatus through an arm 108 (see also Figure 2). The brake body 72b of brake 72 contains a magnetic coil which, when energized, attracts the disc 72a'into engagement with the fixed brake body, thereby resisting rotation of the disc and the associated'sleeve 74 andsprocket 62, and stopping movement of the auxiliary conveyor chains 56.

The clutch 7'@ and brake 72 are arranged to be electrically controlled by a start switch 102 (Figure 2) and a stop switch 113 (Figures 2, 3, 4` and` 5). Concurrently with the arrival at the dispensing apparatusl of the leading space block D of a box-part unit, the start switch162 is actuated to release the brake 7'2` and'- engage the clutch 70, to initiate movement of the auxiliary conveyor chains 56. After one revolution of the chains, the stop switch 110 is actuated to disengage the clutch- 7ftl and apply the brake 72 to stop the chains and to hold them stationary until the leading space block. of the next box-part unit arrives at the dispensing` apparatus.

The start switch 102 (Figure 2) is actuated by a plunger 16251 which is arranged to. be d'epressedfy by aspring nger 1414, the upper end: of whichextendsadjacent the path of one of the main Iconveyor bands C -in position for engagement by an inwardly projectingflug 106 (Figure 6) on the leading space block Dofw a boxpart unit. The leading space blockA D' thusactuates the starting switch 111.21 and initiates movement of the auxil iary conveyorchains 56.

The stop switch 11st? (Figures-2, 3; 4-and`5')1is mountedadjacent one of the auxiliary conveyorl chains 56 on'V a bracket 112. The plunger 119e. of stop4 switch 110l is arranged to. be actuated by a spring finger 114 alsov the4 bralte72is connected to-one terminal 1:18; off a; source,

of electrical: current through agconductor;115iV 'lille 0p.-

wliichthe conveyorchains arcpositef terminal-ofthemagnetic` coi-l in the clutch 707isconnectedthrough the conductor 117 to one of the fixed contacts b' of the stop switch 110 and one of they fixed contacts 1021 of the start switch 102. The other'terminal of the brake 72 is Aconnected through the oonductor 11@ to the other ixed contact 110C of the stop switch 116. The armature 110e! of the stop switch 110 is connected through the conductor 121 to the other fixed contact 102C of the starting switch 102, and the armature 102e! of the start switch 102 is connected through the conductor 123 to the opposite terminal 120 of the source of' electrical current.

The armatures of the switches 102 and lltare shown in solid lines in their normal positions prior to initiation In this of movement of the auxiliary conveyor chains 56. condition of the switches, the circuit from the source of current to the brake 72' is complete through the terminal,

120, conductor 123, armature 102d and fixed contact 162e of start switch 102, conductor 121, armature 110d and fixed contact 110C of stop switch 110, conductors 119 and 11S to terminal 118. The brake 72 is thusy applied to hold the auxiliary conveyor chains in fixed position.

When the leading space block D of a box-part unit' .movement of the auxiliary conveyor chains 56. As soon as movement of the chains starts, the triplug 116 (Figure 5) of the chains moves from engagement with the spring finger 114, releasing the plunger 110e of stop switch 119 and throwing its armature 110e' (Figure l0) from the full-line to the broken-line position. Shortly thereafter, as the mainconveyor bands C continue movement, the trip lng'jlth (Figure 6) on the leading space block D clears the finger 104 and releases the plunger 192:1 of the start switch 102 and throws its armature A 192e] (Figure l0) back to the full-line position. However, the circuit to the clutch is still complete throughA conductor 123, armature 1024i and fixed contact 102C of start switch 1132, conductor 121, armature 111m and fixed contact 114B!) of stop switch 110 and conductors 1.17 and 115. Thus, the clutch 74D is still engaged and the auxiliary conveyor chains will continue to run for a full revolution; Y

After one complete revolution of the auxiliary conveyory chains, the tripl lug 116v (Figure .5) engages theV Y 1- finger-114 to 'actuate the stop switch 110' and cause itsV armature 11M (Figure 10) tovmove to the full-line' Thisv breaks the circuit to the clutch 7() and position. completes the circuit to the brake, as above described. Thus, the clutch is disengaged and thebrake is applied to stop the chains.

In order to keep the slats in line and allow themtoteed freely downwardly as. successive slats are removed'V from the bottom of the stack, means is provided for agitating the slats in the stack. This comprises a pair of angular arms` 127 having at their ends adjacent the stack metal plates 129 with sponge rubber faceV pads 131- secured thereto. These arm assemblies vare pivoted on bolts 133 and are alternatively actuated by means lol"V the central portion of the machine, as above described. The cams 134 are oriented so that their high points are displaced 180 relative to each other, to cause alternative actuation of arms 127 and engagement of the face pads 131 with the edges of the slats in the stack.

Two pairs of exit gates are provided to control the passage of slats from the hopper 22. The primary pair of gates is arranged normally to prevent the passage from the hopper 22 of any except the bottom slat in the stack. These primary gates are so mounted that they may be forced open to allow an exceptionally thick slat or one which is warped or otherwise deformed to pass from the hopper. The secondary pair of gates is arranged to allow such a deformed slat to pass without opening, but normally to prevent the passage of the next slat above.

The primary gate assemblies, generally designated 142 in Figures 3 and 8, are mounted alongside and inboard of the secondary gate assemblies 145. All of the gate assemblies are similarly constructed and arranged. in the following description, reference will be made to one of the secondary gate assemblies 145, which appears clearly in Figures l, 2, 3 and 8; it being understood that the description applies as well to other gate assemblies, except where differences are specifically noted.

Each of the gate assemblies comprises an elongated bar 144 (Figure 2) which is pivoted at 146 between the ends of a pair of horizontal links 148 (see also Figure 8); the links 148 are also pivoted at their opposite ends 150 (Figure 2) on a transversely extending frame member 152 which is supported at its opposite ends on upright posts 154 attached to and extending upwardly from the brackets 34 at either side of the machine. Thus, the gate bars 144 are mounted not only for rotation about their pivots 146 but additionally to permit bodily movement of the gate members 144 by rotation of the links 148 about their pivots 150.

The gate assemblies are urged downwardly, that is, in a clockwise direction about the pivots 150, as viewed in Figure 2, by their own weight. Such downward movement is limited by means of a flange 156 secured to and projecting laterally from one of the links 148 and adapted normally to rest upon a set screw 158 threaded into the top of a bar 160 extending longitudinally of the machine between the transverse frame member 152 and the hopper frame. The set screw 158 is adjustable to facilitate proper positioning of the lower ends 144a of the gate bars 144 relative to the bottom of the stack of slats in the hopper 22. The set screws are normally adjusted so that the lower ends 144a of the bars 144 of the primary gate assemblies 142 are spaced above the level of the supporting members 50 on which the bottom of the stack of slats rests by a distance slightly exceeding the normal thickness of one slat, so as to allow the bottom slat of the stack to pass below the primary gate bars 144, but to prevent the next slat above from leaving the hopper, as it tends to do because of friction between it and the bottom slat.

The lower ends of the gate bars of the secondary gate assemblies 145 are positioned so as to be above the level of those of the primary gate assemblies 142 by a distance approximately equal to the thickness of one slat, as may be seen in Figures 2, 3 and 8.

The gate bars 144 are urged in a counterclockwise direction (as viewed in Figure 2) about their pivots 146 on the links 148, by means of coil springs 163 connected under tension between the upper ends of the gate bars 144 and one of the links 148. Such movement of the gate bars 144 by the springs 163 is limited by means of set screws 164 threaded into the transverse frame member 152 and adapted to engage the underside of the upper end of the gate bar 144. These set screws 164 are adjustable to allow variation of the angle of the inner faces of the lower ends 144a of the gate bars 144; the gatebars T the supporting members 169 and 170 are positioned outare normally adjusted so that these faces are approximately vertical.

This illustrated arrangement of gate assemblies operates, as shown in Figures 9A, 9B and 9C, to permit the passage from the hopper of a slat which is abnormally thick or otherwise deformed without the danger of overloading the mechanism which drives the auxiliary conveyor chains, or jamming slats in the dispensing apparatus. These figures illustrate the case of an abnormally thick slat 162.

In Figure 9A, the thick slat 162 is shown at the bottom of the stack of slats in the hopper 22 at the instant of its engagement by a pair of Slat-engaging elements 54 on the auxiliary conveyor chains 56. As above described, the normal position of the lower ends 144a of the gate bars 144 is such as to permit the passage from the hopper of a slat of normal thickness, but, as shown in Figure 9A, the slat 162 is so thick that the upper corner of its forward edge 162a strikes the lower ends 144:1 of the primary gate bars 144. If the gates were rigidly mounted, the thick slat 162 would obviously cause overloading or breakage of some part of the slat conveying mechanisms or, more probably, the tearing off of one corner of the slat, so that it could not be properly engaged by succeeding slat engaging elements 54. In either event, the result would be interruption of operation of the entire box or crate making machine.

Since the gate bars 144 are pivoted at 146, as above described, the movement of the thick slat 162 by the auxiliary conveyor chains 56 will force the gate bars open, that is, in a clockwise direction about their pivots 146, as shown in Figure 9B, against the resistance of the springs 163.

If the pivots 146 of the gate bars 144 were fixed, this rotation of the gate members 144 by the thick slat 162 would continue past the point shown in Figure 9B to the point at which the lower corner of the end 144e of each of the gate bars 144 was above the upper surface of the slat 162 so that the slat could pass beneath it. It will be apparent that since the arcuate path of the lower corner of the gate bar intersects the upper surface of the slat at a very shallow angle, the vertically downward force imposed by the corner of the gate bar on the slat is subject to considerable mechanical advantage and will be a quite substantial force. This may cause scoring of the tops of the slats, or the drag on the slats may overload the auxiliary conveyor chains. The additional pivoting of the gate assemblies on the links 148 for rotation about the pivots 150 obviates this difculty. Since the entire gate assembly is susceptible of being moved bodily upwardly about the pivots 150, and is urged downward only by its own weight, it is obvious that the pressure exerted on the upper surface of a slat by the bottom corner of a gate bar cannot exceed the weight of the gate assembly. The gate assembly merely rocks upward slightly, as shown in Figure 9C, to allow the lower corner of the gate bar to ride easily over the upper surface of the slat.

Figures 11A, 11B, and 11C illustrate diculties encountered in slat dispensing apparatus of the types heretofore known and used. These figures are diagrammatic views of the stack of slats in the hopper, seen from below and showing the bottom slat 171 of the stack, supporting members 169 and 170 and successive Slat-engaging elements 174, 175 (Figure 11B) and 176 (Figure 11C). The three figures represent successive steps in the feeding of slats from the stack by the previous apparatus. In Figure 11A, the first pair of Slat-engaging elements 174 is shown just engaging the rear edge of the bottom slat 171 of the stack. Assume, for example, that the bottom slat 171 of the stack is warped or otherwise deformed so that the weight of the stack of slats above it causes the bottom slat 171 to engage the left-hand supporting member 169 (as viewed in Figure 11A) with greater force than it engages the right-hand supporting member 170. Since boardofthe pointsoflengagemen'ttof'theslatsfby the: slatt As soon as this" end" of' the slatclears the right-hand-sup-v porting member170; the rotation; ofthe' slatVv will continue, as shown in Figure.` 11B, and' tliel rear edge' of the slat will move away from the right-hand Slat-engaging element 174. The left-hand engagingfielementl174, however, will still engagethe slatandcontinue' its rotation to the point shown in Figure 11C wherethe long axis'of the slat is substantially Vparalleli to the path of movement of the conveyor chains.`

In such position, theslat '171 is. sandwiched'between the left-handl supporting member 169fbelow, andthe left-hand end of the next slat 172V above it in". the stack, and' holds this end of the slat 172 upV so that it will not be-engaged by theV left-hand Slat-engaging element 175 of the next pair of Slat-engaging elements. However, due tov the weight ofthe slats ini the` stack, the right-hand end of this next slat 172 will probably be forced downwardly to rest upon the right-hand supporting member 170; In such position, it will be engaged by the right-hand slat engaging element 17S.y Accordingly, the slat 172 will be rotated about itsv left-hand end.; as a' pivot, as shown in Figure 11C. Its right-hand' end will leavethe hopper, allowing the right-hand end of the third slat 173 to be forced downwardly wherel it will beA engaged by the right-hand Slat-engaging element of the next pair of Slat-engaging elements 176, but the left-hand end of the third slat 173 willbe heldv aboveithe path ofl the lefthand Slat-engaging element 176 by' slats' 171 andi 172. Accordingly, the third Slat- 173; like the secondi slat 172, will be rotated about its left-hand end. Thisrotation or fanning of successive slats will continue until the slats are no longer engaged by either of the slatengaging elements, or until one'of tlie misaligned slats jamsk the auxiliary conveying apparatus. f

In the present" apparatus, this defect is overcome by positioning the supporting members 50 inboard of the path of the auxiliary conveyor chains 56 (as shown in Figures 3 and 6). Accordingly when, due to a deformity in the slats, the bottom slat of the stack is in contact with only one of the supporting members 5'0 or engages one of the supporting members S0 with greater friction than the other, the bottom slat will be engaged by slatengaging elements at either side of the point of maximum drag so that no rotative couple will be set up, but the slat will be fed correctly from the hopper.

Obviously, the same defects in operation which obtain when the supporting members 50 are positioned outboard of the paths of the auxiliary conveyor chains 56 are encountered where the primary exit gates 142 are similarly positioned. Accordingly, as may be seen in Figure 3, the primary gate bars 144 are positioned inboard of the path of the conveyor chains 56. A warped or twisted slat which engages only one of the gate bars will thus be engaged by Slat-engaging elements at either side of this gate bar and will be fed correctly from the stack.

Figures 12A, 12B and 12C illustrate another defect in the operation of previously known slat dispensing ap paratus. These gures, like Figures 11A, 11B, and 11C, are bottom views of the stack of slats, showing the supporting members 179 and 180,

slats

181, 182, 183, and 184 and successive Slat-engaging

elements

185 and 186. As shown in Figure 12A, the bottom slat 181 of the stack has one corner broken olf at 181a. The lefthand engaging element of the pair of engaging elements ticularly if the second slat 132 is warped or otherwise deformed, so that its rear corner drops down into the space left by the missing corner of the slat below. In such instance, the right-hand end of the second slat 182' will be fed from the hopper while the left-hand end of the slat does not move forward, thus rotating the second slat, as shown in Figure 12B, about the left-hand supporting member 179 or about some other point inboard of the left-*hand end of the slat. The portion of the rear edge of the second slat 182 which is adjacent the path of the left-hand conveyor chain does not move forward appreciably. It will thus be engaged by the left-hand slat engaging element 186 of the next pair of Slat-engaging elements, while the right-hand Slat-engaging element 186 is engaging the third slat 183. The third slat 183, being engaged only at its right-hand end is rotated, like the second slat 182, about the supporting member 179 as a pivot, as shown in Figure 12C. This fanningv of successive slats will continue until feeding stops or until the dispensing apparatus is jammed.

Figures 13A, 13B and 13C illustrate the means by which the present invention overcomes this defect. As shown in Figure 13A, as well as in Figures l and 2, the rear angle guides 26 of the hopper 22 are positioned at opposite corners of the stack of slats. If the bottom slat 131 of the stack is broken, as shown in Figure 13A, it will -be engaged only by the left-hand slat engaging element 185. The right-hand Slat-engaging element 185 may engage the next slat 182 above, to cause rotation of the slot 182, as shown in Figure 13B; However, with the illustrated arrangement, the second slat 182 will pivot about the angle guide Z6 aty its left-hand rear corner, and the A rear edge of the second slat 132 adjacent the path of the-left-hand auxiliary conveyor chain will be moved forward by the distance L. This allows the rear edge of the third slat i535'y to move downwardly, along substantially the entire length of the slat, under the force of the weight of theslats above it in the stack. Accordingly, both of the next pairof Slat-engaging elements 186 will engage the third'slat 183 and feed it correctly from the hopper, as shown in Figure 13C. The fanning of slats is thereby 45'. terminated and the feeding of slats will proceed in normal fashion thereafter. The operator needs only to remove the defective slat 131 and properly position the slat 182; this he may do while the main conveyor is moving and without interrupting the operation of the machine.

There is thus seen to have been provided slat dispensing apparatus which is substantially fool proof in that it is capable of accurately and dependably placing slats in position on the rapidly moving conveyor bands of a box or crate making machine operating at high rates of speed, even'though the slats are warped, twisted, broken, of abnormal thickness, or are otherwise deformed.

It must be emphasized, however, that the particular embodiment of the invention which is shown and described herein is intended as merely illustrative and in no way restrictive of the invention.

We claim:

l. In a box-making'machine of the type having a main conveyor for carrying aligned box parts, the combination therewith ofapparatus for dispensing slats comprising a hopper for holding a generally vertical stack of such slats, an auxiliary conveyor movable beneath said hopper and having Slat-engaging elements each adapted to engage and move the bottom Slat from said stack and deposit it on said main conveyor, said Slat-engaging elements being adjustably positioned on said auxiliary conveyor in accordJ ance with the desired pattern of slats in said box-part units, means for driving said auxiliary conveyor including an electrically controlled clutch, a first switch means connected to control said clutch, an operating element adjustably positioned on said main conveyor for actuating said rst switch means to engage said`clutch and start said auxiliary conveyor in properly timed relation to the movement of said main conveyor, Van electrically controlled brake arranged to act upon said auxiliary conveyor, a second switch means connected to control said brake, a switch-operating element mounted upon said auxiliary conveyor for actuating said second switch means to apply said brake and stop said auxiliary conveyor after one cycle of movement thereof, both said rst and second switch means including switch contacts effectively connected in electrical series with the other of said switch -means whereby the actuation of said rst switch means to engage said clutch also releases said brake and the actuation of said second switch to apply said brake also disengages said clutch.

2. Apparatus for dispensing slats comprising a hopper for holding a generally vertical stack of such slats, said hopper being formed of a plurality of generally vertically extending guide members positioned adjacent the stack of slats to confine the same laterally, two of said guide members being positioned at opposite rear corners of said stack of slats and extending downward to a position opposite the bottom slat in said stack, a support at the bottom of said hopper for supporting said stack of slats, a pair of conveyor assemblies movable beneath said hopper and having Slat-engaging elements arranged in parallel pairs for simultaneous engagement with the rear edge of the bottom slat in said stack at points substantial distances inboard from the opposite ends thereof, whereby if the bottom slat in said stack is engaged by a slat-engaging element on only one of said conveyor assemblies, it will pivot about the guide member at the opposite corner of the slat, causing the edge of the slat adjacent the line of movement of the other conveyor assembly to move forward a substantial distance and allow the next slat above to be engaged by both of the next pair of Slat-engaging elements and fed correctly from the apparatus, said hopper being open op posite the forward portion of the ends of at least the bottom several slats in the stack to permit such pivoting movement.

3. Apparatus for dispensing slats comprising a hopper for holding a generally vertical stack of such slats, a conveyor movable beneath said hopper and having slatengaging elements each adapted to engage and move the bottom slat from said stack, at least one exit gate assembly at the front side of said hopper comprising a gate bar pivotally mounted at one end of a generally horizontal link member the opposite end of which is pivotally mounted on the frame of the machine, the lower end of. said gate bar being positioned to permit the passage from said hopper of a properly formed slat of normal thickness, and yieldable means urging said gate bar toward said hopper, whereby said gate bar can be forced back by a slat which is deformed or abnormally thick, and said gate assembly can be moved upwardly by rotation of said link member to limit the downward pressure of said gate bar on slats passing therebelow.

4. Apparatus for dispensing slats comprising a hopper for holding a generally vertical stack of such slats, a. conveyor movable beneath said hopper and having slatengaging elements each'adapted to engage and move the bottom slat from said stack, a pair of primary exit gate assemblies at the front side of said hopper each comprising a gate bar pivotally mounted at one end of a generally horizontal link member the opposite end of which is pivotally mounted on the frame of the machine, the lower end of said gate bar being positioned to permit the passage from said hopper of a properly formed slat of normal thickness, and yieldable means urging said gate bar toward said hopper, whereby said gate bar can be forced back by a slat which is deformed or abnormally thick, and said gate assembly can be moved upwardly by rotation of said link member to limit the downward pressure of said gate bar on slats passing therebelow, and a pair of secondary exit gate assemblies mounted alongside said primary gate assemblies and each comprising a yieldably mounted bar, the lower end of which is positioned above the lower end of the primary gate bars by a distance of the order of the thickness of one of such slats.

p References Cited in the tile of this patent UNITED STATES PATENTS 1,258,989 p Craig Mar. 12, 1918 1,864,776 Stubbs et al June 28, 1932 1,943,444 Knowlton Jan. 16, 1934 2,002,265 Kamper May 2l, 1935 2,075,795 Babcock Apr. 6, 1937 2,253,027 Hall Aug. 19, 1941 2,322,747 Shand .lune 29, 1943 2,535,848 Furminger Dec. 26, 1950 2,648,445 Roessl et al Aug. l1, 1953