US2425210A

US2425210A - Box wrapping system

Info

Publication number: US2425210A
Authority: US
Inventors: John S Stokes
Original assignee: Stokes and Smith Co
Current assignee: Stokes and Smith Co
Priority date: 1942-05-14
Filing date: 1942-05-14
Publication date: 1947-08-05
Anticipated expiration: 1964-08-05

Description

J. s, STOKES BOX WRAPPING SYSTEM 4 Sheets-Sheet 1 Filed May1l4, 1942 VENT OR.

' ATTORNEY.-

Aug. 5, 1947. 5 s o s BOX WRAPPING SYSTEM 4 Sheets-Sheet 2 Filed May 14, 1942 Aug. 5, 1947. J. s. STOKES 2,425,210:

BOX WRAPPING SYSTEM Fil'ed May 14, 1942 r '4 Sheets-Sh eet 5 INVENTOR.

:ATTORNEY.

g- 1947- J. 8. STOKES 2,425,210

BOX WRAPPING v SYSTEM 4 Sheets-Sheet 4 Filed May 14, 1942 INVENTOR.

ATTORNEY.

Patented Aug. 5, 1947 BOX WRAPPING SYSTEM John S. Stokes, Huntingdon Valley, Pa., assignor to Stokes and Smith Company, Philadelphia, Pa., a corporation of Pennsylvania Application May 14, 1942, Serial No. 442,919

15 Claims. (Cl. 9354.2)

My invention relates to box wrapping systems, and more particularly to systems in which coated wrappers are conveyed to a station at which they are assembled with box blanks to form assemblies which are conveyed to a transfer station adjacent the path of form block structure of a box wrapping machine.

In accordance with my invention, the con veyor for transporting the wrappers and assemblies comprises at least two, and preferably three, endless belts which, side by side and substantially contiguous from a station at which they receive the coated wrappers, extend to at least, and preferably beyond, the assembly station and less than all of which, for example only one, extend to the transfer station from which the assemblies are fed to the form block structure.

Further in accordance with my invention, to ensure arrival of the wrappers and assemblies at said stations, respectively, in predetermined orientations and positions, the belts are maintained in side-by-side relation by guides which engage the edges of the belts in portions of their return paths where they move in different planes; more particularly, at least one of the driving rolls, between which the belts are engaged, is of rubber, or similar elastic material, and of tapered cross-section to procure uniformity of pressure applied to the belts by the rolls.

My invention further resides in the features of construction, combination and arrangement hereinafter described and claimed.

For an understanding of my invention and for illustration of an embodiment thereof, reference is made to the accompanying drawings, in which:

Fig. 1 is a plan view of a box wrapping system;

Fig. 2 is a detail view, in side elevation and on enlarged scale, of the receiving end of a conveyor shown in Fig. 1.

Fig. 3 is a detail view, in perspective, showing the relation to each other of the several belts and their guides at the receiving end of the conveyor;

Fig. 4, in perspective, illustrates significant elements of the control arrangement providing for operation of the several components of the'boxwrapping system of Fig. 1 in proper timed relation to each other;

Fig. 5, in perspective and with parts broken away, illustrates details of construction of the conveyor shown in Figs. 1, 2 and 3;

Fig. 6 is a sectional view. in end elevation, showing the construction of the driving rolls for the conveyor of Figs. 1-3 and Fig. 7, a sectional view in end elevation, .illustrates the construction of idler rolls associated with belts of the conveyor of Fig. 6;

Fig. 8 is e. view, in plan, illustrating further details of construction of the conveyor of Fig. 5;

Fig. 9, in perspective, and on enlarged scale, illustrates the relation to each other of parts shown in Fig. 2.

Referring to Fig. 1 as exemplary of a boxwrapping system embodying the invention, the mechanism TG, preferably of the type disclosed in applications Serial Nos. 397,894 and 430,560, filed June 13, 1941, and February 12, 1942, applies a coating of adhesive and adhesively coated tabs T to box wrappers W and in turn delivers them to the receiving end of conveyor 0 which transports them step-by-step to an assembly station AS at which an operator, seated, for example, on the stool I, registers upon them box blanks B in turn bent and delivered to her by the mechanism BlVl, generally of the type disclosed in applications Serial Nos. 338,694, Patent No. 2,295,461, September 9, 1942, and 422,197, filed June 4, 1940, and December 9, 1941.

The assemblies so formed are advanced stepby-step to a transfer station TS adjacent the path of movement of the form block 2 of wrapping machine WM, generally of the type disclosed in United States Letters Patents 2,044,606, 2,074,561 and 2,094,455. An operator at that station, seated, for example, upon the stool 3, in turn removes the assemblies from the conveyor 0 and places them upon or in the path of the form block 2 which during each cycle of the wrapping machine, in co-operation with various tools thereof, completes application of a wrapper W to a blank B to produce a wrapped box.

The disclosed system whose conveyor C has the features hereinafter described is particularly suited for making large boxes, for example suit boxes, of dimensions of the order of 24 inches long, I4 inches wide and 4 inches deep.

As shown in Fig. 4, the mechanism TG includes a one-cycle clutch 5 comprising a driving member 5 continuously connected to and driven wrapping machine WM or by either of the operators by their actuation of treadle l4 or IS, the spring H efi'ects engagement of the clutch members 5, 8 to initiate a cycle of mechanism TG. At the end of the cycle, the clutch member 8 is re-engaged by latch l2 and by it moved out of engagement with the driving clutchmember 5.

During the normal cycle of mechanism TG, a wrapper is lifted from the top of the stack WS thereof by the suction gripper I6, coated with adhesive by the roll I1, Fig. l, and delivered, after application of tabs T cut from strips TS, to" the receiving end of the conveyor C whose driving rolls l8 and I9, Figs. 4-6, are actuated fo'r' th'at fraction of the cycle determined by the relative positions of cams 28, 2|, preferably adjustable with respect to each other, rotatable in unison with shaft 10. Upon engagement of cam 2| with the lower end of lever 22, pivoted on one of

frames

64, 64, the lever $32 is swung in clockwise direction to effect engagement of the clutch members 23 and the former slidably keyed to a shaft with which the shaft 25 of the lower conveyor-driving roll 19 is normally aligned and the latter clutch member mounted on the shaft 25 and which is continuously driven throughout each cycle.

In each cycle of mechanism TG, conveyor C therefore receives a coated wrapper from the ad'- hesive-applying roll I1 and advances it a predetermined distance toward the assembly station AS concurrentl 'with advance to or beyond that Station by the conveyor of the coated wrappers alreadyupon it.

While the conveyor is at rest, the operator at the assembly AS station registers upon a wrapper in front of her a bent box blank removed from the delivery table, or equivalent, of the bending mechanism BM which also, as shown in Fig. 4, includes a one-cycle clutch 26; the relatively movable members of clutch 26 are held out of engagement with each other by the latch '21 which is automatically tripped by cam 28 of the wrapping machine WM in each of its cycles. Latch 21 is reset and the members of clutch 26 disengaged under control of the cam 28A of bending mechanism BM.

While clutch members 26 are in engagement the motor 29 is connected through belt 30, pulley SI and clutch 26 to mechanism which removes a box blank B from the stack BS, bends it along the score lines X and Y and delivers it in predetermined position Bl, Fig. l, in front of the operator upon stool I.

The one-cycle clutch '32 of the wrapping machine WM interposed between the motor 33 and the one-cycle shaft 34 comprises relatively movable members restrained from movement into engagement with each other so long as the cam 35, which makes one revolution for each cycle of mechanism WM, is in engagement with the pin or latch member 36. When either of the treadles 31, 38, located respectively at the transfer and assembly stations, is depressed, the latch or pin 36 is retracted and so allows the clutch spring 39' to effect engagement of the members of clutch 32 and so initiate a cycle of machine WM. At the end of a cycle, unless one or the other of the operators continues to hold treadle- 31 or 38 in depressed position, pin 36 is re-engag'e'd by cam 35 and arm 40 which carries the pin is thereby rotated in clockwise direction to separate the members of clutch 32 in opposition to spring 39.

During each cycle of mechanism WM, the formblock 2 dwells at the upper end of its stroke for a period so timed with respect to the step-by-step operation of conveyor C that the operator at the transfer station may simply slide or lift an assembly directly in front of her from the then stationary conveyor into the path of or onto the form-block while at rest or moving slowly at the top of its stroke.

The extreme width of'the box blanks and of the corresponding form-block 2 makes it impractical, because of hardship upon the operator, to usea' single conveyor belt wide enough to accommodate the wrappers which for at least a substantial time after their coating with fresh adhesive" should be held fiat upon the conveyor C, as by suction.

To allow the operator at the transfer station TS to place the large assemblies upon the formblockwithout undue strain or exertion and yet ensure the wrappers at least until delivery to the assembly station and preferably beyond it are free ofcurlirig, the conveyor C comprises several belts, preferably three, of the same thickness throughout their lengths and breadths, all of which extend from the receiving end of the conveyor adjacent the adhesive-applying roll I! at least to and preferably beyond the assembly station AS but only one of which, for example the belt 4| of width substantially corresponding with the widest box to be wrapped, extends to the transfer station TS adjacent the form-block 2. The other two

belts

42 and 43 disposed on either side of belt 4| may be substantially narrower and of width corresponding approximately with th depth of the deepest box to be wrapped. By way of example,- the overall length of conveyor C may be as long as twenty feet; the loops formed by

belts

42 and 43 may be approximately three or four feet shorter.

By so narrowing the composite conveyor belt, and the suction housing therefor hereinafter described, adiacent the wrapping machine WM and particularly at the operators position thereat, the operator is spared the exertion which otherwise would be imposed upon her if the composite conveyo'r belt were at her station of full width; which is to say, the operator is relieved of that extra exertion otherwise attendant upon reaching a greater distance in transferring each assembly from the conveyor to the machine WM.

Each of the belts 4|, 42 and 43 is porous; any or all of them may be of fabric, or preferably, of fabric impregnated with or covered by rubber and through which are punched a multiplicity of holes to provide the desired porosity for application of suction to the wrappers.

As more clearly shown in Fig. 3, just before any given point on each of the belts arrives at the receiving end of the conveyor each belt is engaged by apair of guides, preferably pulleys having narrow grooves which snugly receive the opposite edges of the belt. The sheaves or

guides

44, 44 engage the edges of the central belt 4! in a plane which is different from, higher than, the plane or planes in which the pairs of

guides

45, 46 engage the edges of the

outer belts

42, 43. By such disposition of the guides, the three belts may bemaintained so close to one another in side by 'siderelation that the upper face of the conveyor C presents a substantially continuous or unbroken surface to the wrappers or sheets carried on that surface.

Near the other end of the conveyor, Figs. 1 and 5, another pair of

guides

41, 41 engage opposite edges of the central belt 4| preferably beyond the transfer station and just before the belt passes about the idler roll 48 for return movement to the receiving end of the conveyor,

Shortly after each increment of length of the

outside belts

42 and 43 has passed over the corresponding idler roll d9 for movement in its return path towards the receiving end of the conveyor, its edges are embraced by a pair of guide pulleys 5B, or equivalent. The pairs of guides 50 are disposed to engage the lower flights of the

belts

62 and 43 in a plane or planes different from that of the lower flight of the adjacent portion of the central belt 4|, By such disposition of guides at opposite ends of the conveyor, each of the upper edges of belts 4!, 42 and 43 is parallel to, aligned with, the corresponding lower edge throughout the length of the conveyor so ensuring the belts throughout the lengths of the endless loops comprising them are movable in directions parallel to each other. There is thus avoided relative motion of areas of different belts in contact with different portions of the same wrapper; such relative motion would cause or tend to cause'undesirable angular movement of the wrapper, positioning it askew on the conveyor during its advance toward the assembly and transfer stations.

The suction housing 52, having the belt-supporting top 54 of character or perforated for application of suction through the porous belts to the sheets or wrappers W, comprises a wide main or central portion which extends from a region adjacent the idler rolls 49 of the narrower belts 42 and 453 to a region adjacent but short of the adhesive-applying roll I! where all three belts pass over idler roll 55 and the suction housing extension 53 pivoted at 5! to the main portion of suction housing 52. Normally, as shown in Figs.

5 and 9, the upper face of the extension 53 isflush with or forms a continuation of the perforated upper plate or surface 56 of the main portion 52 of the suction housing; when for cleaning or other purpose, it is desirable to have access to the adhesive-applying roll ill, the extension 53 may be swung upwardly to position shown in Fig. 2.

The frame 56 which supports the idler roll 55, the conveyor drive-rolls i8, !9 and wrapper feed rolls 51, 58 is pivoted at 59 to the side frames i l, 64 of mechanism TG for movement to and from normal operating position, Fig. 9, from and to the position shown in Fig. 2 affording access to roll ll and stripper blades 58. When frame 55 is swung about its pivot 59 to the latter position, engagement of idler roll 55 with the under side of the suction-housing extension 53 forces the latter to swing about its pivot 5f. Because of location of the pairs of

guides

44, 45 and 46 at fixed points suitably close to the drive rolls i8, i9 and to the pivots 5i and 59 of the suction nose or extension 53 and of the frame 56 respectively, the parallel relation and close spacing of Jelts 6!, d2, 43 with respect to each other is not disturbed by movement of frame 56 and extension 53 from and back to normal operating position.

As most clearly shown in Figs. 3 and 9, the guide sheaves M of belt 4| are supported by brackets 6! attached to suction housing 52' and extending through loops formed by

outer belts

42, 33 respectively; each of the pairs of

sheaves

35, 55 is supported by a bracket 62 suitably clamped to bar 63 extending from one to the other of side-frames 64, E4 of mechanism TG below the conveyor belts 4!, d2, 43.

6 The brackets 62 may each also support, Figs. 2 and 9, the idler rolls 65 which engage the upper faces of the lower flights o-f belts d2, 43 adjacent the pairs of guide sheaves 45, 46 respectively. At suitable distance from each of rolls 65, the under face of the lower flights of each of belts d2, 53 is engaged by another idler roll 6'6, Fig. 5. In effect, the idler rolls 65, G5, and the sheaves d5, d6 adjacent the drive rolls i8, 9 at the receiving end of the conveyor C open the loops formed by

belts

62, 43 to permit engagement of the edges of the central belt fl by sheaves il while those edges are in substantially the same vertical planes as the adjacent, inner edges of

belts

42, 43 and also to permit engagement of the inner edges of belts 52, Q3 by the inner sheaves respectively while those edges are in substantially the same vertical planes as the adjacent edges of belt M.

Near the other ends of the loops formed by belts G2, 43, Fig. 5, the loops are similarly widened or opened by idler rolls 5'1, G8 respectively engaging the under and upper faces of the lower flights of belts d2, d3 to permit'engagement of the inner edges of belts i2, :33, while substantially in vertical alignment with the corresponding edges of the belt 4!, by the inner sheaves 5d of each pair thereof.

For application of suction to the assemblies during their travel beyond the wide portion of conveyor C, there provided the extension 69 of suction housing 52. In width, extension 59 and its perforated top 5 are narrower than housing In UK:

The valve i9, which extends across extension housing 59 near its receiving end, is operable by external handl ll so that the operator at sta- 1 tion TS may suitably regulate the suction there applied to magnitude not hindering removal of the assembly yet sufficient to ensure its delivery to proper position.

As shown in Fig. 8, the opposite sides of housing extension 69 are recessed at E2 and to the housing within each recess is adjustably supported the bearing member 73 for the inner end of shaft i i of idler pulley 59. The outer end of each shaft 'ld is received by bearing member '55 adjustably secured by bolt it, or equivalent, to housing 52. The individual adjustment of each of the bearing members makes it feasible to obtain the desired tension upon

belts

42, 43 and to avoid any tendency to ride toward or away from the central belt; preferably, the pulleys 49 are slightly tapered or crowned, Fig. 7.

To ensure that all three belts start in unison, accelerate in unison, and in general move without relative slip, one of their common driving rolls, for example 18, is of rubber, or equivalent elastic material, and slightly tapered outwardly from its center toward the ends, Fig. 6; for example, the diameter of roll H3 at its ends may be less than at the center. The ends of shaft T? of roll it are mounted in the slidable bearings 18 each pressed by a spring 19 whose tension is preferably adjustable as by a threaded stop 89. By such construction, it has been found the pressure applied by the driving rolls-to the belts is uniform across the entire width of the composite conveyor; in the absence of such uniformity, the belts move different distances in a step of the conveyor C and so twist the wrappers and assemblies askew.

It is sufficient that one of the driving rolls be so tapered though both may be tapered complementarily, to different extents suited to attain aforesaid uniformity; either or both of rolls l8 and I9 may be slidably mounted and biased toward the other.

What I claim is:

l. A sheet-transporting suction-conveyor comprising at least two endless porous belts of different lengths horizontally arranged side by side in close contiguity; a suction housing with a perforate top surface overtraveled by the upper runs of the belts and through which and said belts suction is applied to the supported sheets, said housing having a main portion of a width substantially equal to the combined width of said belts and a narrower continuation beyond one end of said main portion of a width substantially equal to that of the longer belt and offset in respect to the shorter belt, means adjacent the other end of said housing for engaging and driving all of said belts; an idler roll beyond said extension about which the longer belt is trained; an idler roll within the offset of said housing for engaging the aforesaid shorter belt, means for displacing a portion of the lower run of one belt relative to the lower run of an adjacent other belt, and guides for engaging the opposite edges of the displaced portion of the first belt to keep it running tru in close contiguity to the adjacent belt.

2. A sheet-transporting suction-conveyor comprising at least two endless porous carrier belts of different lengths; a suction housing with a perforate surface overtraveled by the active runs of said belts and through which and said belts suction is applied to the supported sheets, said housing having a main portion of a width substantially equal to the combined Widths of said belts and having at one end a narrower continuation of a width substantially equal to that of the longer of said belts; and regulatable means Whereby different degrees of suction may be maintained in the main and the extended portions of said housing for application respectively through all of said belts, and for application through the extended portion of the longer one of said belts.

3'. In a system for wrapping boxes, wrapping mechanism for converting assemblies of boxblanks and coated wrappers into wrapped boxes, a conveyor operative to transport the coated wrappers from a feeding station to an assembling station in advance of. the wrapping mechanism for application to said wrappers of box-blanks, and for transporting the wrapper and box-blank assemblies to said wrapping mechanism, said system comprising a plurality of porous belts arranged side by side in close contiguity to jointly afford a carrier surface sufficiently wide to accommodate wrappers of maximum dimensions, the leading end of at least one of said belts extending past said wrapping mechanism before being reversed in the direction of its movement, to facilitate transfer of the assemblies from the conveyor to said wrapping. mechanism, a suction housing with a perforate surface overtraveled by the active runs of said belts and through which and said belts suction is applied from beneath to the assemblies on said belts, said housing having a main portion extending at least to the assembling station aforesaid of a width equal substantially to the combined widths of said belts, and anarrower continuation extending past said wrapping mechanism and traversed by th extended portion of the longer one of said belts, and valve means to reduce the suction applied to the assemblies upon their approach to said wrapping mechanism.

4'. A conveyor system for transporting wrappers from an adhesive-applying means, comprising a plurality of endless belts arranged side by side in close contiguity to jointly afford a substantially continuous wrapper-supporting surface, a main supporting structure for said belts terminating short of said adhesive-applying means, a supporting structure supplemental to said main supporting structure pivotally mounted adjacent thereto and extending to said adhesive-applying means, and means disposed adjacent the pivotal axis of said supplemental supporting structure for displacing the return runs of one belt with respect to the return runs of another and for contacting the edges of the first belts at the region of displacement to maintain it in parallel relation to the adjacent belt.

5. A conveyor system for transporting wrappers from an adhesive-applying means, comprising a plurality of endless belts arranged side by side in close contiguity to jointly afford a substantially continuous wrapper-supporting surface, a main supporting structure for said belts terminating short of said adhesive-applying means, a supporting structure supplemental to said main supporting structure pivotally mounted adjacent thereto and extending to said adhesiveapplying means, a pivotally mounted throw-back frame carrying drive rolls for said belts adjacent said supplemental supporting structure, and means remaining stationary during movements of said frame and of said supplemental belt-supporting structure to and from positions affording access to said adhesive-applying means, for displacing the return runs of certain of said belts with respect to the return runs of the others and for contacting the edges of said certain belts at the regions of displacement to maintain them in parallel relation to adjacent belts.

6. A system for transporting sheets while subjected to suction including a suction housing, a composite conveyor comprising at least two porous belts driven in unison with their edges arranged in close contiguity to provide a substantially continuous sheet-bearing surface, said composite belt being supported by said housing, through a perforate surface through which and said belts suction is applied to the sheets from beneath, means for displacing portions of the return runs of certain of the belts relative to the return runs of others; means for maintaining the sheet-bearing portions of said certain belts parallel to each other comprising guides engaging the edges of the latter belts in regions of their displacement.

'7. A system for transporting sheets While subjected' to suction including a suction housing, a composite conveyor comprising at least two porous belts driven in unison, each belt forming an endless loop, said conveyor being supported by the housing through a perforate surface through which and said belts suction is applied to the sheets from beneath, means near an end of at least one of said loops for there diverting it out of the plane of another of said loops, and guides engaging the edges of the displaced loop for maintaining the edges of the corresponding belt in close contiguity to those of the immediately adjacent belt and so providing a substantially transversely continuous sheet-bearing surface.

8. In a system for wrapping boxes, a wrapping mechanism for converting assemblies of boxblanks and coated Wrappers into wrapped boxes; a composite conveyor operative to transport coated wrappers from a feeding station to an assembling station in advance of the wrapping mechanism for application thereto of box-blanks, and for transporting the wrapper box-blank assemblies to said wrapping mechanism for manual transfer by an operator there stationed, said conveyor comprising 'a plurality of porous belts arranged side by side in close contiguity to provide a substantially transversely continuous carrier surface, and a suction housing with a perforate surface of a width equal substantially to the combined widths of said belts and through which surface and said belts suction is applied from beneath to the sheets upon the conveyor, the suction housing being diminished in width by as much as the width of at least one of said belts, between said assembling station and said wrapping mechanism, and transport by at least one of said belts terminating approximately at the change in width of the suction housing.

9. A system for transporting sheets including a suction housing, a composite porous endless conveyor overtraveling a perforate surface of the housing through which and said conveyor suction is applied from beneath to sheets carried thereon, said conveyor comprising a relatively Wide center belt and narrower blanking belts arranged side by side in close contiguity to provide a substantially transversely continuous carrier surface, opposed drive rolls contacting the opposite faces of the several belts, means determining the pressures applied to the respective belts by said rolls, the belt-engaging surface of at least one of said rolls comprising elastic material, and the diameter of one of said rolls pro-- gressively diminishing outwardly from the center towards its ends.

10. A system for transporting sheets including a suction housing, a composite porous endless conveyor overtraveling a perforate surface of the housing through which and the said conveyor suction is applied from beneath to the sheets supported thereon, said conveyor comprising a relatively wide center belt and narrower blanking belts arranged side by side in close contiguity to provide a substantially transversely continuous carrier surface, drive rolls engaging the opposite faces of the several belts, the diameter of one of said rolls being uniform throughout, and the diameter of the other of said rolls decreasing progressively outward from the center toward the ends in a direction away from its ends, the belt-engaging surface of at least one of said rolls comprising elastic material, and regulatable resilient means determining the pressures applied to the respective belts by said rolls and in deforming said elastic material in procurement of uniform pressure transversely of all said belts.

11. A system for transporting sheets including a suction housing, a composite porous endless sheet-carrying conveyor overtraveling a perforate surface of the housing through which and said conveyor suction is applied from beneath to the supported sheets, said conveyor comprising a relatively wide center belt and narrower blanking belts arranged side by side in close contiguity, and means for driving said belts and preventing the sheets from skewing thereon comprising drive rolls for engaging the opposite faces of the several belts, the belt-engaging surface of at least one of said rolls comprising elastic material, and

the diameter of one of said rolls progressively diminishing from the center toward the ends, and adjustable resilient means for exerting pressures upon opposite ends of one of said rolls to vary therelative magnitudes of the pressures exerted by said rolls along their lengths to effect equal linear speeds of said belts over said suction housing.

12. A sheet transporting suction-conveyor comprising at least two endless porous carrier belts of different lengths; and a suction housing with a perforate surface overtraveled by the active runs of all the belts and through which and said belts suction is applied to the supported sheets from beneath, said housing having a main portion of a width substantially equal to the combined width of said belts and a narrower end continuation of a width substantially equal to that of the longer belt or belts.

13. A sheet transporting suction conveyor comprising at least two endless porous carrier belts of different lengths; a suction housing with a perforate surface overtraveled by the active runs of all of said belts and through which and said belts suction is applied to the supported sheets from beneath, said housing having a main portion of a width substantially equal to the combined width of said belts and a narrow portion having at one end a narrower continuation of a width substantially equal to that of the longer belt or belts; a suction connection to the main portion of the housing; and an angularly adjustable transverse valve vane at the juncture between the main portion and the continuation of the housing whereby a different degree of suction may be maintained in said continuation from that in said main portion.

14. In a system for Wrapping boxes having wrapper-feeding mechanism, a wrapping mechanism and a box-blank supply station in an interval between the wrapper-feeding and wrapping mechanisms, a suction conveyor comprising at least two endless porous synchronously-progressed belts one extending from the wrapperfeeding mechanism to the box-blank supply station and the other extending from said wrapperfeeding mechanism to said wrapping mechanism; a suction housing having a perforate surface overtraveled by the active runs of all of the belts; and means for maintaining a different degree of suction in the art of the housing overtraveled by the extended portion of the longer belt from that in the remaining portion of said housing.

15. In a box wrapping system, a feeding station with intermittently operated mechanism for delivering individual adhesive-coated Wrapping sheets, an assembling station with mechanism for delivering individual lbOX blanks for application to the wrapping sheets, a wrapping station with mechanism for converting the assemblages into wrapped boxes, conveyor means for receiving the sheets and advancing them to the assembling station, and for advancing the assemblages from the assembling station to the Wrapping station, said conveyor means comprising a plurality of belts arranged side by side in close contiguity to jointly form a substantially transversely continuous carrier surface of a width to accommodate wrapping sheets of maximum dimensions, certain of said belts extending from the sheet feeding station substantially to the wrapping station and the leading end of at least one of the belts extending 1 1 past the wrapping station before being reversed in the direction of its movement to facilitate lateral transfer of the assemblages from the conveyor to the wrapping mechanism, and means for intermittently progressing the conveyor for presentation at each actuation of a wrapping sheet at the assembling station concurrently with presentation of an assembly at the wrapping station.

JOHN S. STOKES.

REFERENCES CITED The following references are of record in the file of this patent:

Number