US2856826A - Machine and method for forming disposable paper pallets - Google Patents

Description

H. H. NORQUIST ETAL 2,856,826 MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19. 1957 15 Sheets-Sheet 1 SQ w R N UNW Oct. 21, 1958 H. H. NORQUIST ET AL 2,856,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19, 1957 15 Sheets-Sheet 2 Oct-21, 1958 H. H. NORQUIST ETAL 2,856,825

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS 15 Sheeis-Shet 3 Filed April 19, 1957 NORQUIST ET AL MACHINE; AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Oct. 21, 1958 15 Sheets-Sheet 4 Filed April 19, 1957 Oct. 21, 1958 H. H; NORQUIST ETAL 2,356,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19, 1957 l5 Sheets-Sheet 5 Oct. 21, 1958 H. H. NORQUIST ETAL 2,355,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS 15 Sheets-Sheet 6 Filed April 19, 1957 Q HI N 3w \Q @N RN m H. H. NORQUIST ETAL MACHINE AND METHOD FOR FORMING Oct. 21, 1958 2,856,826

I DISPOSABLE PAPER PALLETS l5 Sheets-Sheet 7 Filed April 19, 1957 15 Sheets-Sheet 8 NORQUIST El" AL QN MW H. MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS 0 o o o 0 o O O kn? & wk

Oct. 21, 1958 Filed April 19. 1957' Oct. 21, 1958 H. H. NORQUIST ETAL 2,856,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19, 1957 15 Sheets-Sheet 9 Oct. 21, 1958 H. H. NORQUIST ETAL 2,856,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS l5 Sheets-Sheet 10 Filed April 19, 1957 Oct. 21, 1958 H. H. NORQUIST ETAL 2,856,826 MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19, 1957 15 Sheets-Sheet 11 INVENTORS, By Harry /9. 6/7fi6/f/ .A a mi Oct. 21, 1958 H. H. NORQUIST ET AL 2,356,826

I MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19, 1957 15 Sheets-Sheet 12 n v 184K /7/ agwez Oct. 21, 195% H. H. NORQUIST ET AL 2,855,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS l5 Sheets-Sheet 15 Filed April 19, 1957 WHPWWl Mm 11v VEN TOR5. #007 1 7. /2 0/'7z//5/ lliilllllli Oct. 21, 1958 H. H. NORQUIST ETAL 2,856,826 MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Filed April 19, 1957 15 Sheets-Sheet'l4 Oct. 21, 1958 H. H. NORQUIST ETAL 2,356,826

MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PAL-LETS 15 Sheets-Sheet 15 Filed April 19, 1957 Hm m mm AM: g

wmw Q United States Patent 2,856,826 Patented Oct. 21, 1958 lice MACHINE AND METHOD FOR FORMING DISPOSABLE PAPER PALLETS Harry H. Norquist, Hickory Corners, chine Company,

Kalamazoo, and Harry A. Gilbert, M1cl1., assignors to Martinson Ma- Kalamazoo, Mich.

This invention relates to improvements in machine and method for forming disposable paper pallets. Disposable paper pallets are defined as platforms formed of corrugated paper and suitably reinforced to support piles of cartons or other articles for handling as a unit. The pallets are designated as disposable in that they can be manufactured and used a single time and discarded at less expense than would be involved in using a wood or metal pallet and returning the pallet for a second use. The principal objects of this invention are:

First, to provide a machine which will successively bend a prescored corrugated bottom panel into a plurality of hollow U-shaped legs connected at the upper edges by coplaner surfaces and then insert horizontally zigzag reinforcing fillers into the U-shaped legs and finally secure a continuous top panel of corrugated paper over the tops of the bottom panel and the zigzag fillers.

Second, to provide a machine having the foregoing properties which can easily be adjusted to form pallets having different spacing between the U-shaped legs and legs of different widths.

Third, to provide a machine for distributing narrow strips of corrugated paper to the U-shaped legs of a bottom panel and folding the strips into zigzag form for insertion into the legs.

Fourth, to provide a mechanical drive including operating and control cams for actuating the conveyor and panel folding elements of the machine in timed relation.

Fifth, to provide means for forming anchors for the ends of zigzag strips within the U-shaped legs of the bottom panel of the pallet.

Sixth, to provide a novel method of forming a pallet in which a bottom panel is folded into spaced and connected U-shaped legs and reinforcing strips are folded into zigzag form and inserted into the hollow legs and retained at the ends after which a top panel is secured across the tops of the bottom panel and reinforcing strips to prevent the bottom panel and its U-shaped legs from opening laterally from their folded positions.

Other objects and advantages of the invention will be apparent from a consideration of the following description and claims. The drawings, of which there are 15 sheets, illustrate a highly practical form of the machine for forming the pallets and the steps involved in the method of forming the pallet.

Fig. 1 is a side elevational view, broken into two consecutive sections, illustrating the general arrangements,

of the machine.

Fig. 2 is a fragmentary top plan view of the bottom panel forming station of the machine.

Fig. 3 is a fragmentary end elevational view of the bottom panel forming apparatus and station of the machine.

Fig. 4 is a perspective view of the bottom panel of the pallet as it is formed by the mechanism shown in Fig. 3.

Fig. 5 is a fragmentary transverse cross-sectional view through the bottom panel forming mechanism taken along the plane of the line 55 in Fig. v2 and showing the mechanism and a bottom panel in unfolded starting position. An intermediate position of the bottom panel during the folding operation is indicated by the dotted lines.

Fig. 6 is a fragmentary transverse cross-sectional view showing the structure in Fig. 5 in further actuated bottom panel folding position.

Fig. 7 is-a fragmentary top plan view of the reinforcing filler feeding and inserting section of the machine. Portions of the upper parts of the structure are broken away to illustrate lower parts.

Fig. 8 is a fragmentary side elevational view of the reinforcing filler feeding and inserting portion of the machine appearing in Figs. 1 and 7.

Fig. 9 is a fragmentary vertical transverse cross-sectional view through the reinforcing panel feeding and inserting mechanism taken along the plane of the line 9--9 in Fig. 8.

Fig. 10 is a fragmentary top plan view taken along the general plane of the line ltll0 in Fig. 9 illustrating the reinforcing and inserting mechanism in partially actuated zigzag forming position.

Fig. 11 is a fragmentary side elevational view of the structure shown in Fig. 10 with portions of the bottom panel and bottom panel holding mechanism broken away to illustrate the position of the zigzag reinforcing panel.

Fig. 12 is an enlarged fragmentary transverse crosssectional view taken along the plane of the line 99 in Fig. 8 and illustrating in greater detail the reinforcing panel inserting mechanism in fully actuated position.

Fig. 13 is an enlarged fragmentary side elevational view of the reinforcing panel feed and control mechanism illustrated in end elevation in Fig. 12.

Fig. 14 is an enlarged fragmentary horizontal plan view, partially broken away in cross-section, of the reinforcing panel inserting station illustrating the structure for locating and anchoring the ends of the zigzag reinforcing panel in the hollow legs of the bottom panel of the pallet.

Fig. 15 is a fragmentary vertical cross-sectional view taken along the plane of the lines 15-15 in Figs. 14 and 16 and illustrating the abutment forming mechanism in retracted position.

Fig. 16 is an enlarged fragmentary side elevational view of the structure for forming the zigzag panel abutments in the bottom panel.

Fig. 17 is an enlarged fragmentary transverse vertical cross-sectional view through the top panel feeding and attaching section of the machine taken along the plane of the lines 17-17 in Figs. 1 and 18.

Fig. 18 is an enlarged top plan view of the top panel feeding mechanism shown in Fig. 17 with. the top panel attaching press broken away along the plane of the lines 13-18 in Fig. 17.

Fig. 19 is an enlarged fragmentary transverse vertical cross-sectional view showing the top panel attaching mechanism in fully actuated position for connecting the flat top panel to the folded bottom panel and zigzag reinforcing panels.

Fig. 20 is a perspective view of the completed disposable pallet with portions broken away'to illustrate the internal reinforcing elements thereof.

Fig. 21 is a fragmentary transverse cross-sectional view taken along the plane of the line 21-21 in Figs. 18 and 24 and showing the edge of the top panel attaching mechanism in fully actuated position.

Fig. 22 is a plan view of the trailing end of the pallet conveyor at the top panel attaching station showing the drive connections to the conveyor and the structure for laterally adjusting the conveyor, structure for attaching the top panel being omitted.

Fig. 23 is a fragmentary vertical longitudinal crosssectional view taken along the plane of the line 23-23 in Fig. 3 and showing the structure for adjusting the spacing at the front end of the machine.

Fig. 24 is a fragmentary transverse vertical cross-sectional view taken along the plane of the line 24-24 in Fig. -18.

Fig. 25 is a fragmentary transverse vertical cross-sectional view taken along the plane of the line 2525 in Figs. 1, 7 and 8 showing the operating cams for the reinforcing panel folding and inserting mechanism.

The pallet which is formed by the machine and method of the invention is made up entirely of heavy corrugated paperboard of suitable weight. The pallet itself is more clearly illustrated in Figs. 4 and 20 which show the pallet to -be made up of an integral bottom panel 38 that is prescore d longitudinally and folded into depending side legs 31 and a center leg-32 of upwardly opening rectangular U-shaped cross-section. Desirably the inner corrugations within the panel itself extend trans- 'v'ersely of the panel 'as shown at 33 in Fig. 4 so that the folds forming the legs 31 and 32 extend transversely across the corrugation of the panel. The upper edges of the legs 31 and 32 are connected by flat top surfaces 34 that determinethe spacing between the legs. Lateral marginal flanges 35 are left on the outer edges of the outer legs and in the completed pallet these flanges are folded into 'coplaner relation with the connecting top surfaces 34.

The interiors of the hollow legs 31 and 32 are reinforced by zigzag reinforcing panels 36 that are arranged vertically on edge and folded into horizontal zigzag reaches extending between the opposed side walls of the legs. The

open tops of the hollow legs are closed by a continuous flat top panel 37 secured as by gluing to the tops of the connecting surfaces 34 and the marginal flanges 35 and to the upper edges of the zigzag reinforcing panels 36. The longitudinal ends of the zigzag panels 36 are retained longitudinally within the hollow legs by ears 33 struck inwardly from the sides of the legs. Desirably but not necessarily the vertical height of the zigzag panels 36 is slightly greater than the depth of the hollow legs 31 and 32 so that when the top panel 37 is pressed down upon the bottom panel the upper edges of the reinforcing panels 36 are slightly compressed and deformed as appears at 36A in Fig. 19. As thus described the pallet is surprisingly strong and capable of supporting relatively large vertical loads so that fork trucks can be used to handle loads by inserting the forks of the truck between the legs 31 and 32. Because of the ease with which the pallet can be formed with the machine and method described the cost of the pallet is sufiiciently low to permit it to be discarded after a single use.

GENERAL ARRANGEMENT OF THE PALLET FORMING MACHINE tion 40 the details of which appear most clearly in Figs. 2 to 6. From the bottom panel folding station 40 thefolded bottom panels are delivered to the zigzag reinforcing panel feeding and inserting station 41. The details of this station are disclosed in greater detail in Figs. 7 to 16 and 25. From the zigzag forming and inserting station the partially completed pallets are advanced through'an idler station 42 to the top panel attaching "station 43. The details of the top panel attaching sta- -tion appear in Figs. 17 to 22 and 24. When the speed at which the machine is to be operated is slow enough to permit setting of the glued connections at the top panel attaching station 43 this will complete the "machine. However, when the speed of operation of the machine does not provide sufficient drying time in the attaching station 43 an additional holding station 44 in the form of a supporting conveyor 45 and top panel holding conveyor 46 may be added to hold the'top and bottom panels together while the glued connections set.

The several portions and operating elements of the machine are supported by a suitable framework which will be referred to generally by the reference numeral .470. it will be appreciated that various forms of supporting and connecting structures may be devised to support the operating elements of the machine. The pallets and the initial bottom panels 3% on which they are formed are conveyed continuously through the machine in a step by step fashion by a feed conveyor 47 consisting of two transversely spaced link chains supported by suitable rails 43. After the bottompanel has been folded toform the hollow legs 31 and 32, additional conveyor chains '49 supported by rails Stl are provided to assist in supporting and advancing the pallets. The feed conveyor 47 is trained over idler sprockets '51 at the inlet end of the machine and is driven by drive sprockets 52 at the discharge end of the machine. The lower conveyor chains 49 that support the bottoms of the legs are trained over idler sprockets 53 located under the middle of the receiving section 39 (see Figs. 1, 22, and 23) and extend longitudinally through the machine to drive sprockets 54 at the discharge end of the machine. In passing through the toppanel attaching station 43, the lower reaches of the chains 47 and 49 are trained downwardly as at 490 in Fig. 1 to clear the supports that support the pallet'against the pressure of the top panel press.

Drive connections The main power source and drive connections of the machine consist of a motor 55 mounted under the rein forcing panel inserting station 41 and connected to a speed reduction transmission 56 (see Figs. 1, 7 and 8). The transmission 56 has a first power take-off shaft 57 projecting transversely of the machine and connected by the chain 58 to a transverse shaft 59 carrying the gear 66. The shaft 59 drives the reinforcing panel folding mechanism as will be described in greater detail presently. A longitudinally extending output shaft 61 of the transmission drives a first gear and chain 62 with the chain extending upwardly to drive the reinforcing panel distributing and feeding mechanism as will be described. At the forward side of the transmission the shaft of drives a transversely extending chain 63 (see Figs. 7 and 8) that is trained around a sprocket on the longitudinally extending distribution shaft 64. The shaft 64 is chain connected as at 65 to a longitudinal shaft 66 having cams thereon for'actuating various parts of the machine as willappear presently. The transmission shaft 61 also drives a chain 611 to a conveyor drive shaft 612 (see Figs. 1, 7 and'S). A transverse cross shaft 67 located at the rear of the inserting station 41 and under the idler station 42 is driven from the shaft 612 and in turn drives a chain 63 extending rearwardly to a sprocket 69 (see-Fig. 22) on the rear drive shaft-7t). A clutch-71 drivingly.connects the sprocket to the drive shaft for operating the previously described sprockets52 and 54 and the con veyor chains 47 and 43.

Bottom panel folding station 40 The construction and operation of the bottom panel folding station is disclosed more clearly inFigs. 2 to 6 and 23. The flat bottom panels indicated by. the reference character 3% and prescored longitudinally as at 72 are advanced into the folding station 40 where they are supported by the chains 47. Located laterally outwardly from the chains 47 are two longitudinal backing rails73.

.laterally beyond the sides of the rail. jecting above the pressure rail at each end thereof are "of the machine by pivots 102.

side of the machine.

time being the backing rails 73 will be considered as stationary.

At each end of the folding station the cross beams 76 are provided with upstanding brackets 77 rotatably supporting stub shaft 78 on which meshing gears 79 are mounted in the transverse center of the machine between the backing rails 73. The shafts 78 carry longitudinally extending folding plates 80 that are thus swingable or rotatable about longitudinal axis to swing between the outwardly inclined portion shown in Fig. and the upwardly extending parallel portion shown in Figs. 3 and 6. The plates 80 have wooden facing strips 81 bolted thereto which can be removed to increase the effective spacing between the folding plates. One of the plates 80 has a crank arm 83 connec ed thereto (see Figs. 2 and 3) and depending therebelow for connection to a transversely extending push rod 84. The outer end of the push rod 84 is connected to a lever 85 pivotally supported at its lower end on a pivot shaft 86 on the left side of the machine as appears in Figs. 2 and 3. The lever 85 carries a cam follower (not illustrated) engagable with the cam 88 on a cam shaft 89 extending longitudinally along the left side of the machine. Rotation of the cam shaft 89 and cam 88 thus function to oscillate the meshing gears 79 and swing the folding plates 80 between their advanced folding position and retracted open posrtlon.

Positioned in the approximate center of the folding station 40 is an upright air cylinder 90 having a piston 91 therein yieldably supported by a spring 92 (see Fig. 3) and air pressure in the cylinder. The spring 92 normally supports its piston and the piston rod 93 carried thereby in elevated position directly under the center of the bottom panel 30. A top pressure rail 94 of rectangular cross-section is supported longitudinally above a longitudinal shoe 95 on the piston rod 93 in opposed relation thereto. The pressure rail 94 can be changed in width by having the wooden facing plates 81 bolted thereto as indicated by the dotted lines 81A in Fig. 5 when the facing plates are removed from the folding plates 80. The pressure rail 94 has a top plate as that projects Hangers 97 propivotally connected to levers 98 extending laterally to the right side of the machine. The levers98 are pivotally supported at 99 and connected at their outer ends to depending pull rods 1th The pull rods 109 extend downwardly to levers 101 supported at the right side The levers 101 have cam followers 103 engaged with cam wheels 103A on a longitudinal cam shaft 104 extending along the right Rotation of the cam shaft ltld thus functions to raise and lower the pressure rail 94 and when lowered the pressure rail presses the center of the bottom panel against the backing shoe 95 on the .yielda'bly supported piston rod 93 and depresses the .pressure rail and shoe as shown in Fig. 6. In so doing the bottom panel is bowed downwardly as indicated bythe dotted lines at 30A in Fig. 5. After the pressure rail 94 is fully depressed the side folding plates 80 are swung upwardly and inwardly to fold the sides of the center leg 32 of the panel against the sides of the pressure rail 94. The overhanging edges of the top plate 96 of the pressure rail form sharp right angle bends or folds at the upper edges of the center leg as is shown in Fig. 6.

thereon, thepiston 91 has a sealed sliding fit in the cylin- 6 der 91) to draw air into the top of the cylinder through a valve 87. The piston rod has a packed sliding fit (not illustrated) in the upper end of the cylinder. The valve 537 is actuated by a push rod 871 extending from the cylinder to the left side of the machine where it is connected to a lever 872 (see Fig. 2). The lever 872 carries a follower 8'73 engaged with a cam 881 on the shaft The cam 881 is contoured to hold the valve 87 closed until after the bottom panel 30 is fully formed and has been advanced on to the reinforcing panel inserting station 41. The valve 87 is then opened to let air escape from thetop of the cylinder so that the spring 92 raises the shoe to support the next succeeding panel 30 for folding.

Positioned above the cross beams 76 at each end of the folding station 41 are upper cross beams 105. The cross beams 1115 have slideways 106 adjustably supporting bearing blocks 107. The bearing blocks 107 rotatably support cranks 108 slightly above and laterally inwardly from the upper edges of the backing plates 73 (see Fig. 5'). The outwardly and downwardly facing surfaces of the cranks 108 support upper folding plates 109 of angular cross-section that are thus swingable downwardly into opposed relation to the angled backing lates '73. At the front end of the folding station as appears in Fig. 3 the cranks that support the upper folding plates are provided with actuating levers 110 connected to laterally extending push rods 111. The push rods 111 are connected at their outer ends to upright levers 112 pivotally supported at their lower ends on the pivot shafts 36. The levers 112 carry followers 113 engaged with box cams 114 on the ends of the previously described cam shafts 89 and 104. Rotation of the cam shafts $9 and 104 thus functions to swing the upper folding plates 1ll9 downwardly and fold down the laterally inner side walls of the outer legs 31 of the bottom center the plates 117 have crank arms 117A pivotally connected to push rods 118 extending laterally outwardly to upstanding levers 119 on the pivot shafts 86. The levers 119 have cam followers engaged with cams 120 on the cam shafts 89 and 104 so that the side folding plates are swung upwardly to fold up the outer sides of the side legs 31. The marginal flanges 35 of the pallet bottom panel are left standing erect but the panel is partially broken at the score line of the marginal flanges by reason of being drawn outwardly underneath longitudinally extending hold down plates 121 (see Figs. 2 and 3) supported over the side edges of the bottom panel by the support bars 122 connected to the sides of the framework. The folded bottom panel is then ready to be advanced to the reinforcing panel inserting station 41.

Drive and adjustment connections of the bottom panel forming station The cam shafts 89 and 104 which actuate the several folding elements at the folding station are driven from the previously described distributor shaft 64 by laterally extending chain loops 123 (see Fig. 3) trained around sprockets on the distributor shaft and the cam shafts. Rotation of the cam shafts is continuous during the operation of the machine and the angular spacing and configuration of the several cams is adjusted to provide the proper operating sequence of the several folding elements.

The width of the center leg 32 of the pallet can be changed as previously described by removing or chang- I ingthe position of the wooden face plates 81 from the center folding plates to the sides of the pressure shoe 94. In order to adjust the machine for a wider pallet the slides 74 that support the backing plates 73 are moved radially outwardly by rotation of laterally extending screw shafts .124, (see Figs. 3, and 23). The shafts extend laterally to thesides of the machine and there is a pair of shafts at the front and back of the folding station. Chain loops125 are trained around sprockets on the ends of the screw shafts so that all shafts can be adjusted simultaneously.

The bearing brackets 115 which support the side folding-plates 117 also must be adjusted to change the width of the leg sections formed and to this end the bearing brackets1-15 are slidably mounted on the slides 74 and are adjustable with respect thereto by laterally extending screw shafts 126. The screw shafts 126 extend part Way out: toward. the-side of the machine and are connected by chainloops 127 so that adjustment of the hand Wheels 128 will adjust the screw shafts 127. The push rods 11% which actuate the folding plates have longitudinally adjustable connections 129 to permit the proper positioning of the crank arms 116 in all adjusted positions of the bearing brackets 115.

The bearing brackets 107 that support the top folding plates are slidably adjustable on the ways 1116 and are moved laterally by screw shafts 130. The shafts 1315 extend to the sides of the machine where they are connected by chain loops 131 for simultaneous adjustment of the bearing brackets on either side of the machine. The length of the push rods 111 is adjustable by a telescopic section having a releasable clamping connection 132.

Reinforcing zigzag panel inserting station After the bottom panels have been formed to provide the spaced channel shaped legs as described they are advanced by the conveyor chains 47 and 49 to the reinforming panel inserting station 41, the construction and operation of which is most clearly shown in Figs. 7 to 16. Asappears most clearly in Fig. 9 the station consists of a lower support for the chains 47 and 49 and for the bottom of the center legs 32. The support consists of suitable longitudinally extending rails, center rail 133 having side walls 134. Side rails 135 laterally retain the sides of the laterally outer legs. The previously described rails 49 and 50 support the conveyor chains. Positioned immediately above the bottom panel supports are three folding units indicated generally at 136. The center folding unit is fixed over the center leg of the panel and the side units are laterally adjustable'by means of the screw shafts 137 to registerwith the side legs of the panels. Positioned vertically above the folding units is a feed and pressure head 1338 supported on a longitudinal beam 139 that is vertically reciprocal by a crank 141 connected by the suspension rods 142 to the head. A push rod 143 actuates r the head as will be described. The head includes structure for regulating the feed of reinforcing panels to the several panel folding units as will be described. Positioned above-the feed head 13% is a distributor conveyor 144 and control gate 145 that coact with a stationary mag azine 146 to distribute a reinforcing panel to each section of the head 138.

Considering first the distributing conveyor 144 and the gate 145 and with particular reference to Figs. 7, 8 and9. it'will be noted that the magazine 146 is supported in a fixed position along one side of the machine and is considerably longer than the length of the pallets to receive and store long fiat blanks 361 from which the zig zag reinforcing panels 36 are formed. Laterally reciprocable feed shoes 147 sliding between support rails and across the bottom of the magazine feed individual blank strips 361 out of the magazine and into the path of the feed dogs 149 on the transversely extending distributor conveyor chains 144. The feed dogs 149 advance the, strip laterally across the supporting strips of the gate 145. The gate is supported at its front and rear ends by rollers 151 (see-Fig. 9) rollingin atransverse track 152. The gate 145 is reciprocated by a push rod 153 connected to the crank 154 and in turn actuated by a push rod 155. In its retracted position towardthe right side of the machine as appears in Fig. 9, the supporting strips of the gate approach the edges; of the support rails 148 and prevent the panels 361 from falling down; wardly at this point. The reinforcing panels are thus conveyed across the supporting strips 150 of the gate and if t?.e gate in retracted position will fall downwardly over ti left edge of the gate. The left edge of the gate is closable in the advanced position of the gate against the ends of fixed support bars 156 so that reinforcing panels can be translated by the conveyor beyond; the

' The feed shoes 147 are actuated by link conlationship with the gate as will be described.

The feed head 138 carries three longitudinally extending laterally spaced feed chutes 159. Inclined guide rods 160 extending between the sides of the side guide chutes and the edges of the fixed support rails 148 and 156 direct reinforcing panels that fall over the edges of the fixed plates into the side chutes 159. Other inclined bars 161 guide panels that fall over the edge of the gate into the center feed chute.

Each of the inclined bars 160 and 161 carries a movable stop finger 162 designed to intercept and support the reinforcing panels prior to entry into the feed chutes. The fingers 16?. are swingably mounted and connected to be actuated simultaneously by the electrically operated solenoids 163.

To accommodate the head 138 for adjustment along with the other portions of the machines the side, feed chutes are slidably supported and adjustable laterally by screw shafts 164. The shafts 164', are connected on each side of machine by chain loops 165.

After a reinforcing blank has been distributed to each of the intercepting fingers the solenoids 163 are actuated to drop the reinforcing blanks which are then distributed by the feed chutes 159 to the folding units 136.

The construction and operation of the folding units 136 is most clearly illustrated in Figs. 10 to 12. Each folding unit consists of side plates 166, spaced apart by the same distance as the sidse of the pallet leg positioned therebelow, and laterally outer support bars 167. Each side plate is held in fixed spaced relation to its associated support bar by spacers 166A. The ends of the Support bars 167 are adjustably supported from transverse cross beams 168 of the framework of the machine. A transverse shaft 169 extends transversely through both the inner side plates 1'66 and the support bars 167 of all the folding units while stub shafts A project inwardly from the rear ends of the support bars of each folding unit. Transversely projecting seats 170 project from the inner sides of the side plates 166 to intercept and support the edges of the flat reinforcing panels 361 as they are delivered to the folding units by the chutes 159. The lower edges of the chutes are slotted as at 170A in Fig. 11 to clear the seats when the chutes are depressed.

Secured to the upper edges of the outer bars 167 are a plurality of upright bearing brackets 171. The brackets 171 are staggered along opposite sides of the folding unit and support pivot pins 172 about which the laterally outer ends of folding levers 173 are pivoted. The folding levers 173 project inwardly over the side plates 166 and have depending vertical folding arms 174 on their inner ends. Each folding lever 173 carries a depending tappet 175 that is movable laterally between the inner side plate 166 and the outer support bar 167.

The previously mentioned shafts 169 and 169A carry sprockets around which folding chains 176 are trained. The chains carry can. blocks 177 that are selectively positioned and cammed to opposite sides of the chain as indicated at 178 in Fig. 10 to successively engagethe assessed tappets 175 and swing the folding arms 174 inwardly against the fiat reinforcing panel and across the space between the side plates 166 to form the flat panels into the zigzag panels as shown in Fig. 10. Adjustment of the bearing brackets 171 permits adjustment of the spacing of the folding arms and the length of the corrugations formed in the reinforcing panel.

The front edge of the fiat panel 361 is cammed rearwardly and the first fold is formed therein against the transverse cam plate 701 and succeeding zigzag folds are then formed in the panel thus shortening it to clear the rear seat 170. The forward seat 170 is located to lay within a corrugation or fold and so no longer supports the panel. The rear edge of the panel is folded and snapped over a guide rib 702 and located above a vertical guide slot 703 so that when the folded reinforcing panel 36 is pressed downwardly from between the side plates its ends are held against expansion and guided into the proper position in the leg of the pallet positioned therebelow.

In order to prevent the newly folded zigzag reinforcing panel from unfolding and expanding longitudinally from the ends of the legs of the pallet the side walls of the pallet legs are slit and bent inwardly in retaining ears 38 formed by structure appearing in Figs. 14 to 16. At the proper positions, the side rails 135 that support the pallet legs below the folding units are apertured as at 180 and guide plates 181 are secured to the bottoms of the side plates to support air cylinders 182. The guide plates 181 guide upstanding arms 183 connected to the pistons of the air cylinders. The arms 183 carry punch pins 184 that are reciprocated by the air cylinder through the apertures 180 to pierce the side walls of the pallet legs and fold the tabs 38 inwardly. As illustrated the pins 184 are desirably provided with angled shoulders 185 to form sharp bends at the bases of the tabs.

After the three reinforcing panels for each pallet have been folded into zigzag shape, the head 138 and its depending feed chutes 159 are lowered from the retracted position shown in Fig. 9 to an advanced position shown in Fig. 12. The longitudinal extending lower edges of the chutes 159 extend transversely of the upper edges of the reinforcing panels which are now zigzag in shape so that lowering of the feed chutes presses the zigzag reinforcing panels out of the folding units firmly to the bottom of the hollow legs and between the ears 38. The head 138 is then retracted or elevated and the pallet is ready to advance to the top panel attaching station 43. Duringthe folding and inserting of the zigzag reinforcing panels, the distributing conveyor 44 and the gate 145 have been operating to distribute an additional set of three flat reinforcing blanks to the intercepting fingers 162 so that the apparatus is ready to immediately commence a succeeding operation.

Top panel attaching station The folded bottom panels of the pallet with the reinforcing zigzag panels in the legs are advanced by the conveyor chains to the top panel attaching station 43 where the center connecting portions 34 are firmly supported by strong support plates 186 (see Fig. 17). In addition to the conveyor chains the bottoms of the legs of the pallet are firmly supported by plates 187. The marginal flanges of the bottom panel which have heretofor projected loosely from the bottom panel are drawn downwardly by deflecting plates 188 mounted on crank arms 189 at the ends of the station. In this position the top of the partially completed pallet is clear to receive the top panel of the pallet. The top panel 37 is picked up by suction cups 190 carried by a delivery frame 191. The

frame 191 is movably supported at its front and rear ends by a transverse chain conveyor 192 which reciprocates the frame to a laterally disposed pick-up position as shown in Fig. 17 and advances the top panel across a glue applying roll 193. A stop finger 194 engageable by the frame 191 actuates a limit switch 195 to stop outward motion of the pickup frame while a limit step 196 is h gaged by the right edge of the top panel to actuate the limit switch 197 and stop inward feeding motion of the top panel and the delivery frame in proper position over the partially completed pallet. The transverse feed conveyor chains 192 are reversably driven by the motor 198 mounted on the side of the machine. Suitable switching controls not illustrated reversably actuate the motor in timed relation with the other elements of the machine.

The limit stop 196 is pivotally supported at 199 on a supporting beam 200 that is slidably adjustable in the bracket 201 at the side of the machine to permit adjustment for different widths of pallets. The switch 197 carried by the limit stop 196 is urged against an adjustable stop screw 202 by the spring 203.. In order to hold the switch 197 out of contact with the stop screw 202 and to prevent the limit stop 196 from exerting a returning pressure on the top panel 37 after it is released by the suction cups 190, a lock lever 204 is pivoted on the bar 200 and weight biased to fall into blocking engagement with the lug 205 on the stop lever. The switch 197 is thus held in position to reversibly energize the motor 198 until the frame 191 is retracted and until the pressure head 206 is depressed as will be described. The

pressure head 206 carries a trip screw 207 that engages the inner end of the lock lever 204 to release the lock and permit the stop lever 196 to assume its operative position.

In order to permit retraction of the frame 191 and the suction cups to the supply stack of top panels without contacting the glue roll 193 the entire conveyor 192 is carried on a cross frame 208 pivoted at the right side of the machine at 209 and supported at the left side by suspension links 210.

and 24. Longitudinally extending marginal support bars 213 extend along the sides of the pallet underneath the margin flanges and these bars are supported in the center by the piston rods 214 of air cylinders 215. At their ends the bars 213 carry pivots 216 to which the inner ends of the crank arms 189 are attached. As the bars 213 are elevated cam surfaces 217 on the crank arms are brought into engagement with fixed pins 218 to cam the crank arms downwardly against the tension of springs 219 as appears in Fig. 21. This causes the hold down plates 188 to swing laterally out of the way and permit the bars 213 to rise and clamp the marginal flanges 35 against the edges of the top panel 37 and in turn against the bottom plate 220 of the hold down head.

In order that the backing bars 213 and the air cylinders 215 by which they are operated may be moved laterally to accommodate pallets of different widths the cylinders 215 are supported between pairs of longitudinally extending plates 221 connected at their outer ends to upright plates 222 that project upwardly through slots in the fixed bottom panel 223 and through slots in the slide plate 224 for attachment to the under sides of flat slides 225 slidable on the slide plates 224. The upper portion of the air cylinder 215 is flattened and bolted between the plates 221 and has an upstanding journal portion 226 that guides the piston rod 214-. The slide plates 224 which carry the supports for the side legs of the bottom palletv and chain supports 50 have depending ears 227 engaged

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