US3067885A - Automatic panel feeder - Google Patents

Description

Dec..l1, 1962 c. D. KOHLERAUTOMATIC PANEL FEEDER 3 Sheets-Sheet 1 Filed Feb. 24, 1959 IN VEN TOR Conrad 0 Koh/er ATTORNEYS Dec. 11, 1962 c. D. KOHLERAUTOMATIC PANEL FEEDER 3 Sheets-Sheet 2 Filed Feb. 24, 1959 INVENTOR Conrad D Kola/er BY pail ATTORNEYS Dec. 11, 1962 c. D; KOHLER 6 AUTOMATIC PANEL FEEDER Filed Feb. 24, 1959 5 Sheets-Sheet 3 INVENTOR /20 nrad DKoh/er ATTORNEYS 'l/IIl/Il/IIIIIIIIIIII 'IIII/l/lllI/IIIIIIIIIII IIIIII/II/IIIIIIL United States Patent Office 3,067,885 Patented Dec. 11, 1962 3,067,885 AUTOMATIC PANEL FEEDER Conrad D. Kohier, RR. 2, Woodland Road, Shehoygan, Wis. Filed Feb. 24, 1959, Ser. No. 795,238 13 Claims. (Cl. 214-8.5)

This invention generally relates to an automatic panel feeder, and more particularly pertains to an apparatus for automatically feeding rough panels of plywood to a trimming machine.

In accordance with conventional practice, rough plywood panels are fed to a first edge trim machine that is adapted to trim one pair of opposite sides of the panel, after which the direction of movement of the panel is transferred 90 and the ends of the panel are equalized by being fed, behind suitably provided dogs, on a second crosscut trim saw machine; the dogs being provided for purposes of maintaining positive control of the cut in order to achieve absolute squareness in the panel. Since all four edges of the panel are rough when the panel is fed into the first trim machine, positive control of the panel is not necessary, therefore the use of dogs is omitted in the first machine in favor of either rubber-faced plates or a corrugated chain. However, in order to achieve absolute square cuts relative to the side trim in the first machine, the second machine is provided with means whereby the panel is picked up in front of dogs and is pushed through the cutters in the second machine. It is therefore necessary that the timing of the panel feed to the first machine be regulated by the position of the dogs on the second machine in pushing it through the cutters of the second machine. It is accordingly desirable and one of the purposes of this invention, to provide a means whereby a panel can be fed to the first machine in response to a given position of the dogs on the second machine so that there will be no halt or intermittent feed action in the second machine, thereby speeding up the overall cutting and trimming processes.

Accordingly, the instant invention provides an apparatus adapted to feed rough plywood panels to a first trim machine in response to the position of the feed dogs on the second trim machine. More specifically, the instant invention includes means for stacking a plurality of rough ply-wood panels, carried on a dolly, on an elevator platform adapted to rise in such a way as to place the panels in juxtaposition to a pair of push feeder members, which are adapted to selectively push a single panel into a feed means that feeds the panel onto the first trim machine. The feeding occurs in response to the position of the feed dogs on the second trim machine. The instant apparatus includes means for feeding panels of varying thickness, and also includes a means to insure that the panels are fed either one at a time or in controlled stacks of several panels to the first trim machine. It is pointed out that the aforementioned elevator platform rises as either a single panel or a group of several panels are fed off the stack to bring a succeeding panel or panels into position. When the last (bottom) panel has been fed from the elevator platform, suitable automatic means causes the platform to drop to its lowermost position so that the empty dolly may be pushed from the machine, and a new, fully loaded dolly placed thereon, so that the feeding sequence may progress with a new stack of panels.

It is accordingly an object of this invention to provide an automatic panel feeder adapted to overcome the disadvantages inherent in the prior art panel feeders.

Still another object of this invention is to provide an automatic panel feeder adapted to feed panels either one at a time or several at one time from a stack containing a plurality of such panels, said panels being fed to plywood trimming machines.

A further object of this invention is to provide an automatic panel feeder having an elevator platform means for raising a plurality of stacked panels to a feeder means so that said panels are fed either one at a time or in multiples from the machines, and including a means for lowering the elevator platform when the last panel has been fed from the stack.

Still another object of this invention is to provide an automatic panel feeder for feeding plywood panels to panel trimming machine, said machines being arranged at right angles to one another for sequentially making right angle cuts at the edges of said panel, the operation of the instant panel feeder being governed by the position of a first cut panel or panels relative to its time of entry into the second panel trimming machine.

An added object of this invention is to provide an automatic panel feeder adapted to sequentially feed a panel or panels from a plurality of panels stacked on a dolly removably received by the feeder, said panel feeder simultaneously ejecting an empty dolly after the last panel has been fed therefrom and admit another fully loaded dolly to the feeder.

Additional objects and many of the attendant features of this invention will be better understood upon consideration of the following detailed description and draw ings wherein:

FIGURE 1 is a side elevational view of the instant invention partially broken away;

FIGURE 2 is a plan view partially broken away of the instant invention taken on line 2-2 of FIGURE 1;

FIGURE 3 is an end view of the instant invention, as viewed from the right hand side in FIGURE 1;

FIGURE 4 is an enlarged elevational view, partially broken away, of a portion of the structure shown at the right hand side of FIGURE 1 FIGURE 5 is a sectional view taken on line 5-5 of FIGURE 2; and

FIGURE 6 is a schematic diagram of the electrical and hydraulic control system which can be used in conjunction with the instant invention.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts through out the several views there is shown in FIGURE 1 a view of apanel feeder 12 constructed in accordance with the instant invention. Thepanel feeder 12 is supported by four spacedvertical posts 14 that are bolted or otherwise fixedly attached to the floor. Each of thevertical posts 14 is formed of any suitable configuration of structural member, such as either a box beam or a channel member. A pair ofhorizontal beams 16 are attached at their respective ends to a pair of thevertical posts 14, as can be seen in FIGURE 3, and extend longitudinally of the apparatus. In addition, a pair of upperlongitudinal beams 18 of similar construction likewise each have their respective ends fixedly attached to thevertical posts 14 at opposite sides of thefeeder 12, and transversely extendingbeams 20 are attached to thevertical posts 14 at the left hand end of the feeder 12 (see FIGURE 2). Thus thebeam elements 14, 16, 18 and 20 serve to provide a framework for the instant structure.

A plurality ofvertical plates 22 are fixedly attached by welding or the like to the inner face of each of thelongitudinal beams 16, said plates being hereinafter referred to as fence plates, since they are adapted to arrest rolls into said apparatus. It is pointed out that theright hand plate 26 has a forwardlybent portion 27 at its upper end and that said plate constitutes a stationary panel restraining fence.

The instant apparatus further includes a pair ofloading rails 28 having a spring-loadedshoe 30 on its upper surface for arresting movement of a loadeddolly 32 ofplywood panels 34 as it moves down therails 28 toward thefeeder 12. At the right hand end of therails 28, as viewed in FIGURE 3, there is a pair ofcontrol gates 36 that are adapted to stop the loadeddolly 32 as it rolls toward thefeeder 12, so as to prevent entry of the dolly into thefeeder 12 as long as another dolly is already resting thereon. Thegate 36, shown in FIGURE 3, is adapted to be retracted from the dolly arresting position, shown in FIGURE 3, by means of a pair of double actingair cylinders 38, only one of which is shown, attached to the bottom of therails 28, saidair cylinders 38 being actuated in a manner hereinafter set forth and each having its armature connected to agate 36. Thegates 36 are substantially Z in shape and are respectively pivotally connected by pivots 37 to thevertical posts 39 upon whichrails 28 are supported. Eachgate 36 is provided, at its upper end, with aresilient bumper 48. Thebumpers 68 serve to push anempty dolly 32 out of thefeeder 12 when the empty dolly is in its lowermost position, all of which will be described in greater detail hereinafter under the heading of Operation of the Apparatus. A microswitch 42 is attached to the right hand side of theloading rails 28, and is so connected as to actuate theair cylinders 38,

Thefeeder 12 itself includes a collapsible elevator 44 having anelevator platform 46 connected by a suitable andconventional scissors member 48 pivotally connected by a pivot 49 to abase member 50. Theplatform 46 is adapted to be raised by alift plate 52 which has one end pivotally connected at 54 to thebase 50, saidplate 52 having its upper end in sliding contact with the under surface of theplatform 46. Thelift plate 52 is actuated by ahydraulic lift cylinder 56, having one end pivotally connected to thebase member 50 at 57 and having anarmature 58 pivotally connected to thelift plate 52.

When theelevator platform 46 has been raised to its uppermost position, thelift plate 52 is adapted to trip amicroswitch 53 which, in a manner hereinafter described, causes thecylinder 56 to be deactivated so that the elevator platform is allowed to drop to its lowermost position.

The upper surface of theelevator platform 46 is provided with a pair of spacedtracks 60 upon which dolly wheels ofdolly 32 are adapted to roll as the dolly enters thefeeder 12 from theloading rails 28. It is pointed out that thedolly 32 is provided with a stop-detent 62 extending downwardly from its right hand end, as viewed in FIGURE 3, and a switch actuating detent .64 extending downwardly from the left hand end of the dolly. The stop-detent 62, in conjunction with thegates 36, serves to arrest movement of a full dolly onto theelevator platform 46 as the dolly rolls toward thefeeder 12. The detent 64 serves to actuate amicroswitch 66 on the upper left hand side of theplatform 46, as can be most clearly seen in FIGURE 3. Themicroswitch 66 is connected to a suitable solenoid valve, hereinafter described, which in turn actuates thelift cylinder 56, saidswitch 66 being closed when it is actuated by the detent 64 as a full dolly rolls onto theplatform 46. Closure of theswitch 66 actuates thelift cylinder 56, causing the loaded elevator platform to be raised into panel feeding position. The feeding position is at any level of the elevator dependent upon the height of the stack being fed, but always at a level where the top ofdolly 32 is at a higher level than the bottom of theimpact plates 22 thus not only squaring thestack 34,

but prohibitingdolly 32 from jamming the elevator assembly by being caught in the space beneath the lower edge of theplates 22.

A panel hold-downframe 68, having longitudinally extendingbeams 69, is mounted for up and down movement at the upper end of thefeeder 12, said hold-down frame being provided with a plurality of unyielding restraining means, transversely extending hold-downrollers 70, adapted to contact the uppermost panel P on thedolly 32. The opposite ends of the hold-down rollers 70 are attached to a plurality of downwardly extendingbracket members 72, which are fixedly attached to thebeams 69. The hold, downframe 68 is also provided with amicroswitch 74, which is attached to abar 75 extending between thebeams 69 and is adapted to be contacted by the uppermost panel on thestack 34. Themicroswitch 74 is suitably connected, in a manner hereinafter described, to means adapted to arrest upward movement of theelevator platform 46 upon contact of the panel P with theswitch 74. The hold downframe 68 is adapted to be raised and lowered through a suitably provided linkage actuated by acrank 76. When thecrank 76 is rotated it drives ashaft 78 to each end of which is attached abevel gear 80. Each of thebevel gears 88 is in driving contact with abevel gear 82 which is drivingly connected to a threadedshaft 83 threadedly engaged with theframe 68; thus, when theshaft 78 is rotated bycrank 76, rotation of thebeveled gears 82 results, which in turn causes theframe 68 to be either raised or lowered, as desired. To insure an equal lift force on all four corners of theframe 68, acounter shaft 84 is drivably connected to thecrank 76 throughbeveled gears 86 and 88, saidshaft 84 in turn being connected through suitablebeveled gears 90 and 92 to ashaft 94 which is parallel toshaft 78 at the opposite side of thefeeder 12. Theshaft 94 is suitably connected throughbeveled gears 96 and 98 to theframe 68 in the same manner as gears 89 and 82.

At the right hand end of thefeeder 12 there is a pair of feed rollers 188 and 182, which are driven throughbelts 104, 106 and 108 from a first trim machine 110 through a pair of meshed gears 185 and 187. It is pointed out that thebelt 108 passes over an idler roller 189 having the axle thereof located in a slot 111 in thepost 14. The belt 188 is held under tension at all times when theframe 68 is either raised or lowered by aspring 113 having one end attached to the slidableidler roller 109, and the other end to thepost 14. The roller is attached to theposts 14 through brackets 101 on thefeeder 12, while theroller 102 is attached throughbracket 103, to the hold downframe 68.Rollers 100 and 102 feed the panels off thestack 36 in a manner described below. The hold downframe 68 is further provided with athicknessdetermining roller 112 rotatably attached to theframe 68 adjacent to the feed rollers 10%) and 102. The thickness of the panel to be fed can be adjusted on a gauge andpointer arrangement 114 and 116, pointer 116 being fixedly attached to the hold downframe 68, and thegauge 114 being etched or otherwise engraved on thepost 14. It is emphasized that theroller 112 is always in contact with the uppermost panel P on thestack 34 when said panel is being fed from amachine 12. Anadditional microswitch 118 is attached to the right hand end of thefeeder 12 between thevertical posts 14, saidmicroswitch 118 being actuated by the panel P as it is being fed from the machine.

It is pointed out that in order to properly align thepanels 34 against thefence plates 22, the instant apparatus is provided with a plurality ofpositioner arms 120, located adjacent the upper side of thepanel feeder 12. Thepositioner arms 126 are each fixedly attached to arotatable shaft 122, having its opposite ends journaled inbearings 124, fixedly attached to the beam 69 (see FIGURE 2), not shown in FIGURE 1 in order to clarify said figure. Theshaft 122 is actuated by a double-actingair cylinder 126 also attached tobeam 69 and having thearmature 127 thereof drivably connected with theshaft 122 by means of a rack and pinion arrangement (FIGURE 5). Thepositioner arms 120 are activated through themicroswitch 74 in a manner hereinafter described.

Actual feeding of the panels from thestack 34 is instituted by a pair of pusher shoes 128 slidably mounted on a pair of supportingbrackets 130, which are fixedly attached to across frame element 132, which is connected at its opposite ends to the respective side posts 14 located at the left hand side of the panel feeder, as viewed in FIGURES 1 and 2. The feed shoes 128 each have a pusher finger 129 and aguide wheel 134 attached thereto and extending forwardly therefrom at the end of abracket 136. Theguide wheels 134 serve to hold down the left hand end of the uppermost plywood panel P. While the fingers 129 are shown to be of thickness to feed one panel, it is emphasized that they may be made thick enough to feed any desired number of panels at a time. The feed shoes 128 are each actuated by double actingair cylinders 138, fixedly mounted on thebrackets 130, and having thearmature 140 thereof connected to the feed shoes 128. It is pointed out that each feed shoe is provided with anangled surface 142 at its leading edge, which surface 142 serves to break loose a number of the panels at the top of thestack 34, in the event the panels have become stuck together through the presence of excessive glue therebetween.

In order to stop and reverse the action of thecylinders 138, one of the fingers 129 has an upwardly extending detent 131 fixedly attached to its upper surface, said detent being adapted to close amicroswitch 141 fixedly attached to one of a pair of guide bars 143 associated with the fingers 129. Closure of theswitch 141 serves, in a manner hereinafter described, to reverse the action of thecylinders 138 and thus withdraw the fingers 129.

Referring now to FIGURE 6, which is a schematic diagram of the electrical and hydraulic portionsof the instant invention, there is provided in the hydraulic system three solenoid actuated valves A, B and C. A singleaction actuating solenoid 144 is associated with the valve B and is connected, through the normallyopen microswitches 74 and 118, across a D.C. power source E. The valve C is actuated by adouble action solenoid 146 having the opposite ends thereof selectively connectable to one side of the power source E through theswitches 53 and 66 respectively. The valve A is provided with adouble action solenoid 148 having the opposite ends thereof selectively connectable to one side of the power source E by means of theswitches 53 and 66. It is also pointed out that the valves A, B and C are associated with afluid reservoir 149 having apump 151 connected thereto, and are adapted to selectively feed fluid to, or allow exit of fluid from, thelift cylinder 56 through thepipelines 162, 164, 166 and 168, in a manner hereinafter set forth in greater detail.

The spring loadedalignment cylinder 126 is activated by asingle action solenoid 150 connected through theswitches 74 and 118 across the power source E. In addition, thegate actuating cylinders 38 are each actuated in opposite directions by adouble action solenoid 152 having its opposite ends selectively connectable to one side of the power source E through theswitches 42 and 66 respectively.

In addition, thepusher cylinders 138 are actuated by adouble action solenoid 154 having its respective ends selectively connectable to one side of the power source E through theswitch 141 on the panel feeder, and aswitch 156 on the second trim machine, which latter switch is actuated by the position of the dogs on said second machine. Theswitches 141 and 156 are in turn connected to B through what might be termed asafety switch 158, which is of the relay type. Theswitch 158 is closed by the closure of theswitch 74 which serves to complete the circuit for the relay actuating coil.

Thus theswitch 158 is closed only when the topmost panel on thestack 34 is in position to close theswitch 74 so that thecylinders 138 can be actuated only when the topmost panel is in proper feeding position.

Operation of the Apparatus In describing the operation of the instant invention, reference is had to the schematic diagram in FIGURE 5 and the showings in FIGURES 1 through 3 in particular. In describing the sequence of operation of the instant invention, it will be assumed that theelevator platform 46 is at its lowermost position, that is, in horizontal alignment with the upper surface of the loading rails 28. In operating the instant invention, afull dolly 32 is rolled onto the loading rails 28 until thestop detent 62 on said dolly is in abutment with thestop gates 36. When theelevator platform 46 drops to its lowermost position it trips the microswitch 42, which in turn actuates thesolenoid 152 to cause the armature of thecylinder 38 to move in, causing thegates 36 to tilt free of thedetent 62, thereby releasing thedolly 32 and allowing the same to roll onto theelevator platform 46. It is pointed out that just prior to entry of thedolly 32 onto theplatform 46, the bumpers 4t push off an empty dolly, causing the same to roll ofi theelevator platform 46 beneath thefence plates 22.

Before proceeding further, it is pointed out that the hold downframe 68 is adjusted for the desired thickness of either a single panel P or a predetermined number of panels by adjusting, through the action of thecrank 76, the distance between theroller 112 and the upper edge of the offsetportion 27 on thearcuate plate 26.

As the loadeddolly 32 rolls onto theelevator platform 46, the downwardly extendingdetent 64 on the rear of said dolly trips themicroswitch 66, which serves to simultaneously reverse thesolenoid 152, causing the armature of thecylinder 38 to move in, closing the valve A and at the same time energizing thesolenoid 146 to open the valve C to thelift cylinder 56 and thereservoir 149, through the valve B and thepipelines 162 and 164, thereby causing fluid to flow through thepipelines 162 andp 164 into said cylinder and in turn causing said cylinder to lift theelevator platform 46 through the action of thelift plate 52. Theplatform 46 is in this manner raised to the point where a panel feeding cycle begins.

Theelevator platform 46 continues to rise until the top panel P closes themicroswitch 74, which energizes thesolenoid 144, causing valve B to be rotated counterclockwise, valve A remaining closed at the same time, thus causing theplatform 46 to remain at this desired height by shutting off thecylinder 56 from thereservoir 149, and thereby locking therein, the fluid already contained therein. Simultaneously, thesolenoid 150 is energized, causing the armature of thealignment cylinder 126 to be drawn inwardly, thereby causing thealignment arms 120 to push the top panels against thefence plates 22, which insures that the panels are all fed to the first machine 110 in the same lateral position. It is pointed out that the closure of theswitch 74 also causes closure of the relay switch 158'.

The top panel or group of panels is now in position to be fed to the first machine 110 when his signalled to do so by the closure of themicroswitch 156 on the second machine. When theswitch 156 is closed the armatures of theair cylinders 138 are activated and move the pusher shoes 128 toward the top panel or panels, depending on the thickness of the shoes 128 with theguide wheels 134 riding on top of the top panel, thus insuring that only the desired number of panels are fed at a time. The top panel or group of panels is pushed into the powered feed rollers and 102 and at the same time theangled surface 142 on the pusher shoes breaks loose the panels following directly beneath the top group of panels, pushing said under panels against the offset 27 onplate 26. Thesteel thickness roller 112 at the discharge end of the machine serves to hold the load firmly at the desired height so that only the desired .number of panels are fed at a time, saidroller 112 having been set at a specific height by use of thescale 114 and pointer 116. The outward movement of the pusher shoes is halted and reversed when the detent 131 on one of said shoes trips the switch 141 (see FIGURE 2) which, since theswitch 156 has opened, reverses thesolenoid 154 and causes reversal of movement of the armature of eachcylinder 138.

Thepowered feed rollers 109 and 102 then proceed to feed the top panel or group of panels to the first trim machine 110 where the panel or panels are picked up by a power-driven chain on said machine and fed to the cutters. As the panel or group of panels feeds through therollers 100 and 102 the topmost panel finally moves free of themicroswitch 74, causing said switch to open. However, at the same time,switch 113 is still closed by the panel P, thereby retaining the valve B in a counterclockwise rotated position, thus insuring that the elevator mechanism does not proceed to lift the panels to a greater height. When the top panel clears theswitch 118 bothswitches 74 and 118 are then open, thus deactivating thesolenoid 144, causing the solenoid valve B to rotate clockwise 90, and at the same time deactivating thesolenoid 150, causing the armature of thealignment cylinder 126 to be reversed, allowing thealignment arms 12%) to move away from thepanels 34. At this point the switch 153 opens, deactivating thesolenoid 154 and thus thecylinders 138. Since the valve B is now open to thereservoir 149 and thecylinder 56, fluid is pumped from thereservoir 149 to thelift cylinder 56, causing said cylinder to raise theelevator platform 46 until the next top panel contacts and closes themicroswitch 74, at which time the valve B turns to the right and theplatform 46 stops. The above cycle of feeding is repeated.

The above steps continue until the last panel releases theswitch 118, thus deactivating thesolenoid 144, causing the valve B to turn to the left, and in addition,elevator plate 52, in trippingmicroswitch 53, causes valve C to turn counterclockwise 90 or a position, thus short circuiting thepump 151 to thereservoir 149. The closure of theswitch 53 also reverses thesolenoid 148 opening the valve A, thereby allowing fluid to flow out of thelift cylinder 56 due to the downward weight of theelevator platform 46 on thelift plate 52. Theplatform 46 proceeds to drop until it contacts and closes the switch 42 on therails 28, which activates thecylinder 38 in the manner described above, causing the next loadeddolly 32 to be released from therails 28 to move onto theelevator platform 46. At the same time thebumpers 40 move theempty dolly 32 off theelevator platform 46 under thefence plates 22.

It is emphasized that the above cycle of operation may be repeated continuously as long as loaded dollys of plywood panels are fed onto theloading platform 28.

It should be obvious from the above description that the instant invention serves to provide a particularly useful panel feeding apparatus for use in conjunction with plywood trimming machines, which apparatus insures that panels are continuously fed to said machines without undue delay in the feeding cycle. The instant apparatus is substantially fool-proof and is fully automatic once it is started in operation; and, as pointed out above, operation will continue as long as loaded dollys of plywood panels are fed onto theloading platform 28.

In conclusion, while there has been illustrated and described a preferred embodiment of my invention, it is to be understood that since the various details of construction may obviously be varied considerably without really departing from the basic principles and teachings of this invention, I do not limit myself to the precise constructions herein disclosed and the right is specifically reserved to encompass all changes and modifications coming within the scope of the invention as defined in the appended claims.

What is claimed:

1. An automatic panel feeder adapted to sequentially feed a predetermined number of flat panels at one time from the top of a stack of panels comprising: a loading platform; a releasable gate means on said loading platform adapted to selectively hold thereon a movable dolly of stacked panels, an elevator platform, an elevator platform raising means connected to said platform, said elevator platform being adapted to selectively assume a position in alignment with the upper surface of said loading platform; an automatic means for releasing said gate means thereby releasing said dolly of panels from said loading platform for movement onto said elevator platform; a panel feed means adapted to feed the topmost number of panels from said stack onto an auxiliary machine; a panel pusher means adapted to move said topmost number of panels into feeding engagement with said feed means; an actuating means for actuating said elevator platform, raising means for raising said elevator platform until said topmost number of panels is positioned for engagement with said panel pusher means; an arresting means adapted to stop upward movement of said elevator platform when said topmost number of panels is in position for engagement with said pusher means; and automatic means for actuating said panel pusher means to push the topmost number of panels into feeding engagement with said panel feeding means; means for automatically actuating said elevator platform raising means upon complete clearance of said topmost number of panels from the panel feeder to raise said elevator platform a distance equal to the thickness of said number of panels, thereby bringing the next predetermined number of panels in the stack into alignment with said panel pusher means, whereby successive panels are adapted to be automatically, sequentially fed from the panel feeder, at detecting means adapted to lower said elevator platform to its lowermost position upon the feeding of the last panel on said stack from the panel feeder, and an ejector means for ejecting the empty dolly from the elevator platform when said elevator platform reaches its lowermost position, said ejector means and said gate means being simultaneously actuated so as to release a loaded dolly of panels from said loading platform for movement onto said elevator platform, whereby a successive stack of panels is adapted to be fed from the panel feeder without interruption.

2. An automatic panel feeder, as set forth in claim 1, wherein the elevator platform raising means comprises a lift member having one end bearing against the underside of the elevator platform, said lift member being actuated by a hydraulic lift cylinder, and wherein the means for arresting upward movement of said elevator platform comprises a microswitch located on the panel feeder above the topmost panel on the stack, said microswitch being adapted to be closed by said topmost panel, the closure of said microswitch actuating a valve means to close flow of fluid to said hydraulic lift cylinder.

3. An automatic panel feeder, as set forth in claim 1, wherein the means for arresting upward movement of said elevator platform comprises a first microswitch located at the intake side of said panel feeder means, and a second microswitch located at the discharge side of said panel feeder means, said first microswitch being adapted to be contacted and closed by said topmost panel as the elevator platform rises, said first and second microswitches being connected to a means adapted to stop the elevator platform raising apparatus, thereby arresting upward movement of the elevator platform upon closure of said switches whereby when said topmost number of panels is being fed from the panel feeder it closes both of said microswitches, thereby maintaining the elevator platform in arrested position until said topmost number of panels completely clears the panel feeder, including the second microswitch.

4. An automatic panel feeder as set forth inclaim 3,

9 wherein the elevator platform raising means comprises a lift member driven by a hydraulic lift cylinder, and the lift arresting means includes a valve connected to said cylinder and is adapted to be closed in response to the closed position of said microswitches so as to arrest fluid flow to said cylinder and thus movement of said cylinder and therefore upward movement of elevator platform.

5. An automatic panel feeder, as set forth in claim 1, wherein the means for arresting upward movement of said elevator platform comprises a first microswitch lo cated at the intake side of said panel feeder means, and a second microswitch located at the discharge side of said panel feeder means, said first microswitch being adapted to be contacted and closed by said topmost panel as the elevator platform rises, said first and second microswitches being connected to a means adapted to stop the elevator platform raising apparatus, thereby arresting upward movement of the elevator platform upon closure of said switches whereby when said topmost number of panels are being fed from the panel feeder it closes both of said microswitches, thereby maintaining the elevator platform in arrested position until said topmost panel completely clears the panel feeder, including the second microswitch.

6. An automatic panel feeder for consecutively feeding panels from the top of a stack of panels comprising:

(a) a main frame including vertical support members;

(b) an elevator means within said frame adapted to receive said stack of panels and to urge said stack upwardly in said frame;

() longitudinally extending beams mounted above said elevator on said vertical support members;

(d) unyielding restraining means dependent from said beams and disposed in a generally horizontal plane for positively limiting the upward movement of said stack by contacting the topmost panel therein;

(2) a stationary panel restraining fence secured to said frame adjacent one end of said elevator, said fence having a horizontal top edge spaced downwardly with respect to the plane of said restraining means;

(1) panel pusher means secured to said frame at the opposite end of said elevator for initiating movement of panels from the top of said stack by displacing them towards and across the top edge of said fence;

(g) panel feed means mounted on said frame and on said beams in position to receive panels displaced by said panel pusher, said panel feed means completing the removal of the panels displaced by said panel pusher means during the operation of said automatic panel feeder.

7. An automatic panel feeder as in claim 6 wherein means are provided for adjusting said restraining means vertically.

8. An automatic panel feeder as in claim 6 wherein said restraining means comprises a plurality of rollers having axes generally perpendicular to the direction of movement of said panels and having stack contacting surfaces which are substantially co-planar.

9. An automatic panel feeder as in claim 6 wherein said elevator means has a stack receiving position and panel feeding positions and wherein automatic means are provided to trigger the raising of said elevator means from said panel receiving position to panel feeding position in response to the entry of a stack of panels into said elevator.

10. An automatic panel feeder as in claim 9 wherein means are provided for automatically arresting the upward movement of said elevator when said stack reaches a panel feeding position.

11. An automatic panel feeder as in claim 9 wherein means are provided for automatically lowering said elevator to its stack receiving position when a stack of panels has been completely expelled from the machine.

12. A cyclic panel feeder adapted to sequentially feed 10 a predetermined number of flat panels at a time from the top of a stack of panels, comprising:

(a) a frame;

(b) elevator means within said frame adapted to receive said stack of panels and to urge said stack upwardly in said frame;

(0) vertically adjustable, longitudinally extending beams mounted above said elevator means in said frame;

(d) a plurality of transverse, co-planar, hold-down rollers spaced longitudinally from one another along said beams and depending therefrom for positively limiting the upward movement of the said stack by contacting the topmost panel therein as the elevator means rises;

(e) means for interrupting the operation of said elevator when the top of said stack comes into cont-act with said hold-down rollers and for preventing further operation of said elevator until after a feeding cycle has progressed to the extent that the predetermined number of panels being fed during said cycle has cleared said stack;

(1) a stationary panel restraining fence secured to said frame adjacent one end of said elevator, said fence having a horizontal top edge spaced downwardly with respect to the plane of said restraining means;

(g) panel pusher means secured to said frame at the opposite end of said elevator for initiating movement of panels from the top of said stack by displacing them towards and across the top edge of said fence;

(h) panel feed means, including an upper feed roller mounted transversely on said beams in alignment with said hold-down rollers and a lower feed roller mounted upon said frame outside said fence, said feed rollers being in position to receive panels displaced by said panel pusher, said panel feed means being adapted to complete the removal of the predetermined number of panels displaced from said stack by said panel pusher means.

13. A cyclic panel feeder adapted to sequentially feed a predetermined number of flat panels at a time fromthe top of a stack of panels, comprising:

(a) a frame;

(1)) elevator means within said frame adapted to selectively assume a loading position for receiving a dolly of stacked panels;

(0) means connected to said elevator means for initiating the operation of said elevator in an upward direction in response to the arrival of said dolly at its proper position on said elevator means, thus urging said stack upwardly in said frame;

(d) vertically adjustable, longitudinally extending beams mounted above said elevator means in said frame;

(e) unyielding restraining means dependent from said' beams and disposed in a generally horizontal plane for positively limiting the upward movement of said stack by contacting the topmost panel therein, while permitting longitudinal movement of said topmost panel;

(f) means for interrupting the operation of said elevator when the top of said stack comes into contact with said restraining means and for preventing further operation of said elevator means until a feeding cycle has progressed to the extent that the predetermined number of panels being fed during said cycle has cleared said stack;

(g) a stationary panel restraining fence secured to said frame adjacent one end of said elevator, said fence having a horizontal top edge spaced downwardly with respect to the plane of said restraining means;

(h) panel pusher means secured to said frame at the opposite end of said elevator for initiating movement of panels from the top of said stack by displacing them towards and across the top edge of said fence;

11 (i) panel feed means mounted ,on said frame .and on said beams in position to receive panels displaced by said panel pusher, said panel feed means completing the removal of panels displaced by said panel pusher means during a given cycle in the operation of said automatic panel feeder; (j) means for detecting the exhaustion of said stack and :for returning said elevator means :to said loading position in response thereto.

1,174,739 Langston Mar. 7, 1916 12 Reynolds Apr. 6, 1935 Van Vleck Jan. 18, 1949 Pabich Apr. 19, 1949 Johansson Sept. 23, 1952 Matteson Nov. 10, 1953 Schubert Jan. 12, 1954 Smith May 3, 1955 Guigas Dec. 18, 1956 Shields June 13, 1961 FOREIGN PATENTS Germany Aug. 1, 1957

Images