US3708951A

US3708951A - Sealer for random size shipping cases

Info

Publication number: US3708951A
Application number: US00058536A
Authority: US
Inventors: D Folk; C Pavnica
Original assignee: Bemis Co Inc
Current assignee: Amcor Flexibles North America Inc
Priority date: 1970-07-27
Filing date: 1970-07-27
Publication date: 1973-01-09
Anticipated expiration: 1990-01-09
Also published as: CA948163A

Abstract

Apparatus for sealing shipping cases including a sealing section adjustable upon the receipt of a signal from a case sensing means to accommodate successive cases of different dimensions and a compression section also adjustable to accommodate such cases, the adjustment of the compression section being controlled by the adjustment of the sealing section and being timed to occur following the entry of a case into the sealing section and the discharge of the previously sealed case from the compression section.

Description

United States Patent 91 Folk et al.

[4 1 Jan. 9, 1973 [54] SEALER FOR RANDOM SIZE SHIPPING CASES [75] Inventors: Dennis L. Folk, Lincoln Park; Cyril A; Pavnica, West Reading, both of [73] Assignee: Bemis Company, lnc., Minneapolis,

Minn.

[22] Filed: July 27, 1970 [2]] Appl. No.: 58,536

[52] US. Cl ..53/75, 53/374 [51] int. Cl ..B65b 57/02, B65b 7/20 [58] Field of Search ..53/75, 76

[5 6] References Cited UNITED STATES PATENTS Keely et al ..53/75 3,085,376 4/19'63 Ferguson et al. ..53/75 3,183,639 5/1965 Rodman 3,374,604 3/1968 Roesner et al ..53/75 Primary Examiner-Travis S. McGehee Attorneylrving Powers and Peter S. Gilster [57] ABSTRACT Apparatus for sealing shipping cases including a sealing section adjustable upon, the receipt ofa signal from a case sensing means to accommodate successive cases of different dimensions and a compression section also adjustable to accommodate such cases, the adjustment of the compression section being controlled by the adjustment of the sealing section and being timed to occur following the entry of a case into the sealing section and the discharge of the previously sealed case from the compression section. v

4 Claims, 7 Drawing Figures PATENTEDJAN 9 I975 sum 1 BF 4 Q mm PATENTEDJAN 9 I975 3.708.951 SHEET '4 [IF 4 SEALER FOR RANDOM SIZE SHIPPING CASES BACKGROUND OF THE INVENTION The present invention concerns machines or apparatus for closing and sealing fiberboard shipping cartons and cases, hereinafter referred to as cases, and more particularly to such apparatus adapted to accommodate cases of different widths and heights successively delivered to the apparatus in random sequence.

A conventional case sealing apparatus includes a sealing section through which the loaded case is conveyed and in which an adhesive is applied to certain of the case closure flaps and the flaps then brought into overlapping relationship. The conventional further includes a compression section to which the cases are delivered by the sealing unit and in which the closure flaps are maintained under pressure in their overlapped closed condition until the adhesive has taken a sufficient set that the flaps will not re-open when a case is discharged from the apparatus. In operation one case is carried through the compression section while a succeeding case is carried through the seal' ing section.

Where the apparatus is .of the type to accommodate cases of different dimensions delivered in random sequence as in the present situation both the sealing and the compression units must be adjustable to position the mechanisms carried thereby and which operate on the cases, namely the glueheads, flap closers, etc. in the sealing section and the belt or other device for applying pressure to the closed'flaps ofa case in the compression section, in accordance with the dimensions of each case delivered to the apparatus. As will be recognized if one signaling and adjusting mechanism is em- 7 ployed for both the sealing and compression sections both sections must be emptied before the adjustment can take place thereby reducing the capacity ofthe ap- 4O paratus.

One solution to the problem of securing the necessary adjustability in both the sealing and compression units without sacrificing capacity or efficiency has been to employ separate structures for the twounits. In this received from the sealing unit, when the compartment is in the case receiving position, to cause it to adjust to accommodate the next case to be delivered to it by the sealing unit.- Case sealing and compression units as described above are disclosed in patent to Ferguson et al. U.S. Pat. No. 3,085,376, issued Apr. 16, l963 relating to the sealing unit and patent to Ferguson U.S. Pat. No. 3,125,842, issued Mar. 24, 1964, relating to the compression unit. As will be appreciated the units of these patents are relatively complicated and expensive and while they serve their functions in an efficient manner they fail to meet the needs of simplicity and low cost as required in many packaging operations.

apparatus 15 SUMMARY OF THE INVENTION The principal object of the instant invention is to provide an improved apparatus for sealing cases of different dimensions which are successively received in random sequence, the machine including a sealing section having means controlled by a case sensing means to adjust itself to accommodate any particular size of case within a given range and also including a compression section having adjustment means to permit it to accommodate the different cases handled by the sealing section, the extent and direction of the adjustment being dictated by the sealing section. Also the apparatus includes means for so timing the adjustment of the compression section with respect to the adjustment of the sealing section that, during the adjustment of the sealing section to accommodate a case andthe treatment of such case therein, a case of different dimensions may be passing through the compression section.

The case sealing apparatus or machine attaining the foregoing effect includes a main frame structure supporting means for conveying asucce'ssion of cases of random dimensions through a sealing section and a compression section. A first sub-frame assembly or elevator is supported from the main frame in the sealing section for vertical adjustment toward and away from'the conveying means. The sub-frame assembly carries-the various mechanisms required for'operating upon the flaps of a case to apply adhesive to selected flaps and to fold the flaps into adjacent overlapping relationship. The vertical adjustment of the first subframe assembly is made by a motive means under the control of a photo-electric sensing means such as shown for example in patent to Fergusonet all U.S. Pat. No. 3,085,376 whereby under the direction of such sensing means the sub-frame assembly is moved by said motive means upwardly or downwardly to the proper height to accommodate a given case upon the admission of such case to the machine.

The compression unit of the apparatus comprises a second sub-frame assembly or elevator carried by the main frame-structure and supporting means for applying pressure to the closed flaps of a case within the-unit. The second sub-frame assembly is mounted for vertical adjustment by motive means individual to the compression unit. The operation of the motive means is effected by a control member carried by the first sub-frame assembly and which in cooperation with an electrical circuit serves, upon the adjustment of the first sub-frame assembly to accommodate a case, to signal the motive means for the second sub-frame assembly as to the direction and extent of the movement whichthe second sub-frame assembly is to take to accommodate said case. The timing of the operation of the second motive means is under the control ofa cam operated switch included in the electrical circuit and is such that said motive means will be energized when the case in the sealing unit is approaching the compression unit and a previously sealed case has completed its travel through the compression unit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a case sealing apparatus in accordance with the instant invention;

FIG. 2 is a diagrammatic sectional view with parts omitted of a portion of the machine of FIG. 1 and taken longitudinally of FIG. 1;

FIG. 3 is a diagrammatic sectional view with parts omitted taken in the direction of the arrows 3-3 of FIG. 1;"

FIG. 4 is a top plan view of a portion of the apparatus looking in the direction of the arrow 4 of FIG. 3;

FIG. 5 is, an elevational view of a portion of the apparatus looking in the direction of the arrow 5 of FIG.

FIG. 6 is a top plan view, with parts in section, of a portion of the apparatus looking in the direction of the arrow 6 of FIGIS; and

I FIG. 7 is a wiring diagram illustrating the electrical control system of the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsiand particularly FIG. I there is disclosed an apparatus or machine for closing and sealing filled conventional fiberboard shipping.

cases within size-ranges as determined by the size of the machine itself. Such cases have opposite side flaps of a width approximately equal to one-half the width of the I case. The cases are fed to the machine in any desired order'with the bottom end flaps folded in, the bottom side flaps folded thereunder and the top and end side flaps in substantially erect positions. I

The machine has a main frame-comprising vertical members 10 and horizontal members 12 and 14 providing a sealing section indicated generally at 16 and a compression section indicated generally at 18. The cases to be sealed are fed through the machine by suitable conveying means which includes an infeed conveyor 20, chain conveyor 22 and a belt conveyor 24. Chain conveyor 22 which extends through the sealing section comprises a pair of parallel chains 26 mounted on sprockets carried by suitable bearings supported by the frame structure, thechainslying on opposite sides ofthe apparatus. The chain's carry transverse flight bars 28, two of suchbars being employed. Be'lt conveyor 24 which extends through the compression unit and serves as a support for the cases while under compression as bearings carried byframe members36. Infeed belt 20,

chain conveyor 22 and belt conveyor 24 are continuously driven by means of a motor or motors (not shown) in any suitable way.

The sealing section 16 of the machine, which suitably maybe of the same type as the sealing unit disclosed in patent to Ferguson et al. U.S. Pat. No. 3,085,376 previously referred to although a somewhat simplified version is illustrated in the instant application/includes a sub-frame assembly or first elevator indicated generally at 38 overlying chain conveyor 22 and mounted for vertical movement, toward and away from the co'n-. veyor. The mounting for the sub-frame assembly, which is similar to. the mountingdisclosed in FIG. 6 of said U.S.-Pat. No. 3,085,3 76, comprises shafts40 supported for rotation in suitable bearings on opposite sides of the assembly as by brackets 42. The shafts carry gears 44 (see, FIG. 5) in intermeshing engagement with racks 46 "supported by the vertical frame members 10 at the four corners of the sealing section.

Shafts 40 are driven by a reversible motor '48 mounted on the sub-frame assembly through a chain 50, a sprocket 52 affixed to a shaft 54 extending transversely 5 of thesealing section, and worm gears 56 secured' to the shaft, each worm gear being in intermeshi'ng en gagement with a worm wheel 57 on one or the other of mechanism for applying adhesive to certain of the upper flaps and for the closing of the flaps of the case into overlapping sealing relationship. S'uch mechanism may take any suitable form such as that, for example, shown in U.S. Pat. No. 3,085,376, and hence .is not illustrated in detail. However for present purposes the mechanism is assumed to includea hot melt gluehead of conventional type .(not shown) adapted to apply stripes of glue or other adhesive to the upper end flaps of the case as the case moves through the sealingsection with the end flaps infolded but with the upper side flaps remaining in their substantially erect positions. The infolding of the end flaps is automatically performed prior to the case reaching the gluehead by conventional flap tuckers, the tucker for the forwardflap being indicated by the reference character 49 in FIG. 3 and the tucker for the rear flap being indicated by the reference character 51 in FIG. I. As the case approaches the forward end of the sealing sectionthe Y folded end flaps and to thereafter bring the side flaps into sealing underlying relationship with the end flaps before the case leaves the sealing section. These means, which involve only conventional structure, are not shown in detail, reference again ,being'made to U.S. Pat. No. 3,085,376 for such detail, butas illustrated' in FIG."1 they-comprisetaper rolls-53 supported from the framework on opposite sidesof the sealing section atits case receiving end whereby the bottom side flaps are permitted to open tosome extent. The means also includes a package plate 55 (see FIG/.2) a tapered end of flaps as the case, passes from the taper rolls onto the package plate. The package plate is suitably constructed and arranged to permit application of an adhesive in stripes to the end flaps, a hot melt gluehead 59 being illustrated for this purpose. Following the application of the glue, and as the case approaches the forward end of the sealing section, conventional flap folders (not shown) fold the side flaps into sealing relationship with the end flaps.

The sealing section of the machine includes mechanism for detecting the height and width ofa case deliveredthereto and for effecting the necessary ad justments of sub-frame assembly 38 to accommodate thecase, such mechanism being of thetype disclosed in said U.S. Pat. No. 3,085,376. The mechanism for determining the width of the case and which also serves to center the case is best illustrated in FIGS. 1,3 and 4.

which enters between the side flaps and the closed end- The mechanism comprises width bars 58 and 60 having their rear ends pivotally connected to one end of links 62, only the link for the bar 58 being shown, the other end of each link being pivotally connected to a fixed frame member. The width bars 58 and 60 adjacent their forward ends are supported by links.63 and 64 respectively, link 63 being in parallelism with link 62 on the same side of the machine and of equal length therewith and link 64 similarly being in parallelism with and of equal length to the link 62 on its side of the machine. Links 63 and 64 are affixed to the upper ends of

vertical shafts

65 and 66 respectively mounted for rotation in frame members of the machine as shown. The lower ends of the

shafts

65 and 66 are affixed to lever

arms

67 and 68 respectively which in turn are connected by

links

69 and 70 respectively to the upper ends of

lever arms

71 and 72 respectively carried by and affixed to a transversely extending shaft 74 supported for free rocking movement in bearings (not shown) in opposite side frame members of the machine. Shaft 74 (see FIGS. 3 and 4) has affixed thereto a lever arm 73 carrying a.fo llow'er roller 75 at its outer end'for rolling contact with a cam 76 affixed to a shaft 77. Lever

arms

78 and 83 are also affixed to shaft 74 adjacent the opposite ends of the shaft,

lever arms

78 and 83 being urged to rotate and to hence cause rotation of shaft 74 in a clockwise direction as viewed in FIG. 3 by tension springs 87 and 89 connected to the lever arms and to fixed frame members of the machine. Cam 76 is so positioned on shaft 77 and shaft 77 is so rotated in a counterclockwise direction as viewed in FIG. 3, as will be explained more in detail hereinafter, that follower roller 75 is on the high portion of the cam during the travel of a case onto taper rollers 53. As will be understood, when roller 75 is on the high portion of cam 76 shaft 74 has been rocked to in turn through the linkages described rotate links 63 and 64 to separate width bars 58 and 60 to their greatest extent. Upon continued rotation'of shaft 77 and cam 76, roller 75 will eventually ride off the high point of. the cam and down the slope thereof. As the cam follower passes from the high point, springs 87 and 89 cause shaft 74 to rotate in a clockwise direction as viewed in FIG. 3 to, through the linkages described above, move width bars 58 and 60 inwardly, such movement continuing until the case has been centered in the machine and further inward movement is prevented by the contact of the bars with the opposite sides of the case/Upon continued rotation of cam 76, follower roller 75 will besuspended out of contact with the cam, or, where a case of minimum width is involved, will ride on the low portion of the cam, until the cam is rotated sufficiently to bring the opposite slope thereof into contact with the follower. As will be apparent, further rotation of the cam will move the width bars apart until as the cam follower rides onto the high portion of the cam the width bars are again in the posi-- tion shown in FIG. 4. g

The height sensing operation for the vertical adjustment of sub-frame assembly 38 is accomplished electrically. As previously noted the machine of the instant invention is adapted to seal regular fiberboard cases which have side flaps ofa width approximately equal to one-half the width of the case. Inasmuch as the cases are delivered to the machine with the side flaps substantially upright the height sensing means is adapted to determine the position of the upper extremity of the side flaps and means are provided as will be hereinafter described for compensating for the flap height so that the height adjustment .of the sub-frame assembly is actually made in accordance. with the height of the case with the flaps closed.

For the height sensing operation tw'o photo electric units 79 and 80 (see FIG. 7) are employed similarly as in U.S. Pat. No. 3,085,376 each unit including a light source and a photo electric cell. The light source 81 (FIG. 1) of unit 79 and the photo electric cell 82 of unit 80 are mounted in fixed positions on a bracket 85 which is slidably mounted for vertical movement on a pair of rods 86 secured in and projecting upwardly from a horizontal frame member 88 of the sub-frame assembly. Light source 81 is at a slightly elevated position relatively to photo electric cell82. Photo electric cell 91 of unit 79 and the light source 92 of unit 80 are similarly mounted on a bracket 94 slidably supported for vertical movement on a pair of rods 96 secured to and projecting upwardly from a frame member 98 on the opposite side of the sealing unit from frame member 88. Photo electric cell is directly opposite and in horizontal alignment with its light source 81 and similarly light source 92 is directly opposite to and in horizontal alignment with photo electric cell 82.

The means previously referred to for compensating for the width or height of the side flaps of the case in the machine, such width or height being determined by the width of the case as noted above, includes the

lever arms

78 and 83 secured for rocking movement with shaft 74 and adjacent the opposite ends thereof. The lever arms are connected by flexible cables or

Bowden wires

100 and 102 and through suitable fittings to brackets 85 and 94 respectively. In operation and upon the rotation of shaft 74 following the riding of cam follower 75 off the high portion of cam 76 and the consequent rotation of

lever arms

78 and 83,

Bowden wires

100 and 102 will move brackets 85 and 94 downwardly from upper rest positions the extent of such movement being determined by the degree ofrotation of shaft- 74 permitted by the movement of width bars 58 and 60 into their case centering and case width measuring positions.

Referring now particularly to FIGS. 1, 5 and 6 the construction of the compression section of the machine will be described. The compression section includes a sub-frame assembly or second elevator indicated generally at 104 adapted for vertical movement and supporting'upper compression belt 106 carried by end rollers, one being shown at 108 (FIG. 5), the conveyor belt having a lower run traveling in the same direction and in parallelism with the upper run of conveyor belt 30. The lower run of belt 106 is supported to enable it to exert a compressing force on 'a case passing therebeneath by a series of rollers 110 having their shafts mounted in bearings in side-members of the sub frame assembly. Belt 106 is adapted to be driven in any suitable way at the same speed as the lower belt 30 as, for example, the shaft of an end roller 108 of the upper conveyor may be connectedby a suitable sprocket and chain with a sprocket carried by ashaft of one of the end rollers of the lower conveyor with the driving relationship being such that the lower and upper, runs,

respectively, of two belts will travel at the same speed and in the same direction. However, as any equivalent conventional drive means may be employed, none has been shown;

The vertical movementof sub-frame assembly 104 is effected by means of a reversible motor 112 mounted thereon. A sprocket 114 carried by thedrive shaft of motor 112(FIG is connected by a sprocket chain 116 with a sprocket-118 secured to a transversely extending shaft 120 mounted in suitable bearings (not shown) in the frame member of the sub-frame assembly. Shaft 120 carries worm gearslocated adjacent the oppositesides of the sub-frame assembly, one of said worm gears being shown at 122m FIG. 5. The worm gears mesh with worm wheels carried by shafts mounted for rotation in bearings on opposite sides of the sub-frame assembly one of the worm wheels, its supporting shaft and a bearing therefor being indicated at 124, 126 and 127 respectively in FIG. 5. Each of the shafts 126 carries. gears 128. at its opposite ends, the gears-meshing with racks 130. extending longitudinally of and supported by vertical frame membersat the four corners of the compression section.

Referring'again to FIGS. 5 and 6 a vertically extending control bar 132 is secured to the sub-frame assembly 38 of the sealing unit at the forward end thereof adjacent the compression section. One edge of the control bar, the edge to the left as viewed in FIG/5, is provided with ainotch 134 approximately midway of its length. The other-edge of bar 132', from its upper end'to a point opposite notch 134 is cut away as illustrated in FIG. 5, thewider and narrower portions of the bar being connected by a slant 136 the midpoint of which lies horizontally opposite to the apex of the notch 134. Thus, the bar 132 has at its right edge offset portions constituting upper and lowersections.

A bracket 142 projecting upwardly and then horizontally from a frame member of sub-frameassembly 104 carries a single action switch 144 and a double action switch 146 the switches having

actuating members

148 and 150 respectively. These switches (as to which 146 may be termed afirst control and 144 a second control) are so positioned and are ofa type that

rollers

149 and 151 carried by actuating

members

148 and 150 ,respectively,x ride on theopposite edge faces of the control bar and follow the contours thereof.

Switches

144 and 146 are included in an electrical circuit which will hereinafter bedescribed.

As illustrated particularly in FIG. 2, in which parts are shown diagrammatically, chains 26 of conveyor 22 as previously mentioned are carried by a series of contact the actuators of switches 172 and 174 (FIG. 7) I v i and hence momentarily close the switches upon each rotation of the cam. As previously pointed out chains 26 carry two flight bars 28 the bars being individually identified in FIG. 2 as 28a and 28 b the spacing of the flight bars being equal to one-half the length of the.

chain. The relative diameters of sprockets 162 and 164 I are such that shaft 77, and hence the cams carried and a light source 178 are mounted on opposite sides of theunit in positions to have the light beam to the photoelectric cell broken upon the delivery of a case to the sealing section. The photoelectric cell 176 is insprockets including

end sprockets

152 and 154 mounted for rotation with

shafts

153 and 155 respectively supported: in bearings (not 'shown) on the machine frame, drive sprockets 156 which are mounted for rotation with shaft157 the shaft being driven by an electric motor or the like (not shown), suitably mounted adjustable slack take-up sprockets 159 and sprockets l58. Sprockets 158 are affixed to a shaft 160 supported from the frame in bearings (not shown). Shaft160 carries a sprocket 162 connected in driving relationship'to a sprocket 164 by a chain 166. Sprocket 164 is fixed to shaft 77 previously referred'to. Shaft 77, on which cam 76 is mounted, also carries a cam 168 (FIGS. 1 and 7) having'a riser 170 adapted to cluded in the electrical circuit controlling the operation of motor 48 and functions to maintain the circuit open when there is no case in theentry portion of the sealing unit. I

The electrical circuitry for the several motors and control elements previously referred to will now be described. Motors 48'and 112 are conventional three phase AC induction motors of the reversible type the direction of rotation of the motors being changed by reversing any two ofthe leads thereof. The motor circuit includes main leads adapted to be connected by a'master switch 182 to anysuitable source of three phase electrical current. Electrical current is supplied to the motors from leads 180 through either one of two paths as determined by the energization of the coils of one orthe other of

relays

184 and 186. As will be noted from FIG. 7, upon the energization of relay 186 current will flow to the motor through leads .188 contactors 190, when closed, and leads 202. On the other hand, upon energization of the coil of relay 184 the current will flow through leads 204 which are connected into leads 188, contactors 206, when closed, leads 20s and leads 202. As will be observed, the inner lead 188 will now be connected to the outer lead 202 and similarly the outer lead 188 will be connected to the inner lead 202 whereby the motor will rotate in a direction oppositeto. the direction of its rotation when the coil of relay l86 is energized. In the machine being described, energization of the coil of relay l84 will cause the motor -to rotate in a direction to move sub-frame assembly 38 downwardly and energization of the coil of relay 186 will cause the 'motor to rotate in a direction to move the-sub-frame assembly upwardly. v

Motor 1l2'is similarly connected to the-main leads through two different paths one including relay'2l0 and the other relay 212. Upon energization of the coil V of relay 212 leads 214, which form a continuation of the main leads 180, are connected to the motor through contactors 216, when closed, and leads 218. When the coil of relay 210 is energized power is supplied to the motor from the leads 214 through leads- 220 contactors 222, when closed, leads 224 and leads 218. As will be noted the inner and outer leads, with respect to their connection to motor 112, are reversed upon energization of the coil of relay 210 as compared to their connection when the coil of relay 212 is energized. In the circuitry illustrated energization of the coil of relay 210 will cause rotation of the motor in a direction to lower sub-frame assembly 104 and conversely energization of the coil of relay 212 will cause upward movement of the sub-frame assembly.

The circuits controlling the energization of the coils of

relays

184 and 186 will now bedescribed. One terminal of the coil of relay l84is connected by a lead 226 to a power lead 228 which in turn is connected to one of the main leads 180. The other terminal of the coil is connected by a lead 230, contactor 232 of relay 186, whenclosed, lead 234, contactor 236 of a relay 238, when closed against contacts 240, contactor 242 of a relay 244, when closed against contacts 246, a power lead 248, the contactor 250 of a relay 252, when closed, lead 256, switch 172, when closed, and lead 258 to a lead 260 which in turn is connected to a second of'the main leads 180. Similarly one terminal of the coil of relay 186 is connected by a lead 262 to lead 228 and the other terminal of the coil is connected by a lead 264, contactor 266, when closed,

contactors

236 and 242 of

relays

238 and 244, when closed against

contacts

268 and 270 respectively, to lead 248 which is connected to the power lead. 260 as previously described.

Inasmuch as switch 172 is only momentarily closed by cam 168 holding circuits are provided for both relays. Thus with respect'to relay 184, upon energization of it by closing of switch 172, contactor. 272 is closed thereby connecting power lead 260 through lead 274 and leads 276 and 278 to lead 256. Similarly upon energization of the coil of relay 186 contactor 280 thereof is closed connecting lead 274 through leads 282 and 278to lead 256.

One terminal of the photoelectric cell of unit 79 is connected by a lead 284 to power lead 260. The other terminal of the photoelectric cell is connected by a lead 286 to one terminal of the coil of relay 238. The other terminal of the coils is connected by a lead 288 to power lead 228. The photoelectric cell of unit 80 has one terminal thereof connected by a lead 290 to power lead 260 and has its other terminal connected by a lead 292 to one terminal of the coil of relay 244 the other terminal of the coilbeing connected by a lead 294 to powerlead 228. Thephotoelectric cells of

units

79 and 80 are of a known type which operate to close the circuits to the coils of their respective relays when the light beams arebroken. Photoelectric cell 176 which similarly operates to close a circuit when the light beam is broken, has one terminal thereof connected by a lead 296 to power lead 228 and the other terminal connected by a lead 298 to one terminal of the coil of relay 252. The other terminalof the coil of the relay is connected by a lead 300 to a power lead 260.

'Referring now to the lower portion of the wiring diagram of FIG. 7 the control of the energization of the coils of

relays

210 and 212 will be described. One terminal of the coil of relay 210 is connected by a lead 302 to power lead 228. The other terminal of the coil is.

connected by a lead 304, contactors 306 of relay 212,

when closed, and lead 308 to a terminal 310 of doubleacting switch 146. Similarly one terminal of the coil of relay 212 is connected by a lead 312 to power lead 228. The other terminal of the coil is connected by a lead '314, contactor 316 of relay 210, wheiiclosedpand a 336 connected to power lead 260, Similarly the holding I circuit for the coil of relay 212 includes a contactor 338, lead 340 connected to lead 328 and lead 342 connected to power lead 260.

The operation of the machine of the instant invention will now be described. The machine is in operation with camshaft 77 rotating and the upper run of chain conveyor 26 and the upper and lower runs respectively of

belt conveyors

30 and 106 traveling in a direction to carry cases in succession through the sealing and compression sections. it will be assumed that the chain conveyor has carried a case to a point just beyond the width bars 58 and 60 of the'sealing section and that the belt conveyors have completed the travel of a previous case through the compression section. Under such circumstances one of the flight bars will be at the position indicated by the arrow 343 and the other will be in the position indicated by arrow 344. Also follower roller of lever 73 will be on the high portion of cam 76 and as a consequence width bars 58 and 60 will be in their outermost positions. As there isno case in the entry end of the sealing'section the light beams to photoelectric cells 82 and of

units

79 and 80 respectively are unbroken and in consequence the coils of relays 2 38 and 244 are de-encrgized and

contactors

236 and 242 are in the positions illustrated in FIG. 7 closing against

contacts

268 and 270 respectively. Also the beam from the light source for photoelectric cell 176 is unbroken and hence the coil of relay 252 de-energized and contactor 250 separated from contacts 254. I v

A case which may be of any dimensions within the adjustment capabilities of the machine is now delivered by infeed conveyor onto taper rollers 53, the case having at least its upper side flaps substantially erect. As the case enters the sealing unit itwill break the light beam to photoelectric cell 176 permitting the energization of the coil of relay 25 2 and the consequent closing of the contactor thereof against contacts 254 whereby the-circuit is closed between

leads

248 and 256.

As the advancement of the chain conveyor and the rotation of camshaft 77 continues follower roller 75 will ride off the high point of cam 76 and width bars 58 and 60 will move into contact with and center the case. Also

photoelectric cells units

79 and 80 will be lowered on

rods

86 and 96 through the medium of the

Bowden wires

100 and 102 to a position determined by the width of the side flaps of the case. These adjustments occur as one of the flight bars, such as bar 28a, in FIG. 2 closely approaches theposition shown in that figure. in the meantime depending upon the dimensions of the case, as compared to the dimensions of the last previous case which passed through the sealing section, the light beams of

photoelectric cell units

79 and 80 will either be broken or remain undisturbed. In either situation motor 48 will remain de-energized due to open switch 172. As the travel of the conveyor continues and a flight bar reaches the position of the flight bar 28a of FIG. 2 the lobe or riser 170 of cam 168 will be moved into position opposite the actuating member of switch 172 to momentarily close the switch thus energizing the control circuit for motor 48.

In the event that the case is of such dimensions that the photoelectric cells of

units

79 and 80 have their light beams interrupted,the coils of

relays

238 and 244 will be energized to cause contactors 236 and 242' to close the circuit which causes motor 48 to rotate in a direction to elevate sub-frame assembly 38, the operation ofthe motor continuing until the circuit is broken by the upper of the two cells passing beyond the edge of the case flap. On the other hand if the light beams to the cells remain unbroken, the coils of the relays will not be energized and motor' 48 will be driven in a direction to lower the sub-frame assembly until the light beam of the lower 'of the units is broken by the case flap and in consequence the coil of the relay controlled by that unit is energized. The adjustment of subframe assembly 38 to the proper height, as determined by the photoelectric cell units, causes similar adjustment of control bar 132 which moves upwardly and downwardly with the sub-frame assembly from its rest position as shown in-FlG. 7. Movement of the control bar from its rest position causes actuator of switch 144 to.close' between leads 328 and 324 and, depending upon the direction of the movement of the bar, causes actuator 150 of switch 146 to close against one or the other of

contacts

310 and 320. However as switch 174 remains open at this time the circuit to motor 112 is also open In' the m eantime switch 172 has been permitted to open but due to the holding circuits the operation of motor 48 continues until the circuit to it is broken by the energization of the coil of one of the

relays

238 or 244 as described above.

The above described operations take place during the movement of a flight bar from the position of the bar 28a of FIG. 2 to a position in which it is in contact with the case resting on taper rolls 53. The continued travel of the chain conveyor carries the case through the sealing sectionvthe several operations previously described being performed-on the case. During thecontinued travel ofthe case camshaft 77 continues to rotate and as the leading edge of the case approaches the compression unit cam 168 is rotated to bringits nose 170 into position to close the actuator of switch 174 thereby closing the circuit controlling the operation of motor 112 the motor causing elevation or lowering of the sub-frame assembly] 04 depending upon the circuit closed'by thecontactor of switch 146. The raising or lowering movement will continue until the contactor of switch 144 enters notch 134 and the contactor of switch ,l46 is on slant 136. At this point the subframe assembly 104 is prepared to receive the case from'the sealing section.

Having thus described the invention in rather complete detail it will be understood that these details need not be strictly adhered to, and that various changes and modifications may be-made all'falling within the scope of the invention.

We claim:

1. ln apparatus for sealing cases which have open upper flaps,

a sealing section wherein adhesive is applied to certain of the upper flaps after which the flaps are closed,

a compression section wherein pressure is applied to the closed flaps,

'a continuously operable conveyor including pusher means for moving said first elevator up and down to adjust it relative to said conveying means to position said flap sealing means for operation on cases of different heights before the pusher means engages'a case in the sealing section,

a second elevator in said compression section movable up and down relative to said conveying means I to accommodate cases of different heights with their upperflaps closed, means carried by and movable with said second elevator for applying pressure on the closed flaps ofa case travelling through the compression section after exiting from the'sealing section, reversible drive means for moving said second elevator up and down to adjust it relative to said conveying means to-position said pressure-applying means for operation on cases of different heights, a control member carried by one of said elevators extending vertically with respect to said one elevator, a first control carried by the other of said elevators engageable with said control member for controlling the direction of operation of said drive means, said control member having an upper section and a lower sctionengageable by said first control, and said first control being operable when engaging one of control member sections to effect operation of. the drive meansin one direction for lowering the second elevator and operable when engaging the other of said control member sections to effect operation of the drive means in the opposite direction for raising the secondelevator, and a second control carried by said other elevator engageable with the control member for controlling the extent of movement of the second elevator, said control member having means at the level of the juncture of its said upper and lower sections engageable by said second control for stopping said drive means when said second elevator, in moving either up or down, reaches the level for applying pressure to the caseexiting from the sealing section, a v v and means operable in timed relation with said conveyor for initiating operation of said drive means in one direction or the other as determined by the position of the first elevator as 'a case approaches the compression section during its passage through the sealing section. 1

2. ln apparatus as set forth in claim 1, said control member being carried by said first elevator and said first and second controls being carried by said second elevator, said first control being operable when engaging said upper section to effect operation of the drive means in one direction for lowering the second elevator and operable when engaging said lower section to efmember is in engagement with said lower section and in said opposite direction when said operating member is in engagement with said upper section, and said second control comprising a second switch having an operating member engaging said control member, said second switch being connected in a circuit for energizing the motor when its operating member is above or below said stopping means and deenergizingthe motor when its operating member is at said stopping means.

4. In apparatus as set forth in claim 3, said control member comprising a vertical bar having at one vertical edge offset portions constituting its said upper and lower sections, with said stopping means constituted by a notch in its opposite vertical edge,

Claims

1. In apparatus for sealing cases which have open upper flaps, a sealing section wherein adhesive is applied to certain of the upper flaps after which the flaps are closed, a compression section wherein pressure is applied to the closed flaps, a continuously operable conveyor including pusher means adapted to come into engagement with a case in the sealing section and to push it through the sealing station and thence through the compression section, a first elevator in said sealing section movable up and down relative to said conveying means to accommodate cases of different heights, flap sealing means carried by and movable with said first elevator for applying adhesive to certain of the said upper flaps of a case in the sealing section and for closing said flaps, means for moving said first elevator up and down to adjust it relative to said conveying means to position said flap sealing means for operation on cases of different heights before the pusher means engages a case in the sealing section, a second elevator in said compression section movable up and down relative to said conveying means to accommodate cases of different heights with their upper flaps closed, means carried by and movable with said second elevator for applying pressure on the closed flaps of a case travelling through the compression section after exiting from the sealing section, reversible drive means for moving said second elevator up and down to adjust it relative to said conveying means to position said pressure-applying means for operation on cases of different heights, a control member carried by one of said elevators extending vertically with respect to said one elevator, a first control carried by the other of said elevators engageable with said control member for controlling the direction of operation of said drive means, said control member having an upper section and a lower section engageable by said first control, and said first control being operable when engaging one of contrOl member sections to effect operation of the drive means in one direction for lowering the second elevator and operable when engaging the other of said control member sections to effect operation of the drive means in the opposite direction for raising the second elevator, and a second control carried by said other elevator engageable with the control member for controlling the extent of movement of the second elevator, said control member having means at the level of the juncture of its said upper and lower sections engageable by said second control for stopping said drive means when said second elevator, in moving either up or down, reaches the level for applying pressure to the case exiting from the sealing section, and means operable in timed relation with said conveyor for initiating operation of said drive means in one direction or the other as determined by the position of the first elevator as a case approaches the compression section during its passage through the sealing section.

2. In apparatus as set forth in claim 1, said control member being carried by said first elevator and said first and second controls being carried by said second elevator, said first control being operable when engaging said upper section to effect operation of the drive means in one direction for lowering the second elevator and operable when engaging said lower section to effect operation of the drive means in the opposite direction for raising the second elevator.

3. In apparatus as set forth in claim 2, said reversible drive means comprising a reversible electric motor, said first control comprising a first switch having an operating member engaging said control member, said first switch being connected in a circuit for operating the motor in said one direction when its said operating member is in engagement with said lower section and in said opposite direction when said operating member is in engagement with said upper section, and said second control comprising a second switch having an operating member engaging said control member, said second switch being connected in a circuit for energizing the motor when its operating member is above or below said stopping means and deenergizing the motor when its operating member is at said stopping means.

4. In apparatus as set forth in claim 3, said control member comprising a vertical bar having at one vertical edge offset portions constituting its said upper and lower sections, with said stopping means constituted by a notch in its opposite vertical edge.