US3021610A - Apparatus for transporting blanks through a drying zone - Google Patents

Description

Feb. 20, 1962 WINKLER ETAL APPARATUS FOR TRANSPORTING BLANKS THROUGH A DRYING ZONE 2 Sheets-Sheet 1 Filed Nov. 18, 1958 INVENTORS R/c/mro/ Mnk/er and K010 Dunne/er A r roams-r 1962 R. WlNKLER ETAL 3,021,610

APPARATUS FOR TRANSPORTING BLANKS THROUGH A DRYING ZONE Filed Nov. 18, 1958 2 Sheets-Sheet 2 1 A m A "o INVENTORS A //'c/)Qrd M'mf/cr a and Kara fiu/mebler- BY A MZW 1 v meur v s I states 1 This invention relates to envelope making machines, and more particularly to an apparatus for transporting envelope blanks through the drying section thereof to dry the gum on flap portions of the blanks. For example, envelope machines have a section wherein blanks are lapped one upon another, to leave only those portions of the sealing flaps exposed to which the gum is to be applied by means of a roll applicator in the form of a continuous band of adhesive. After application of the gum, the blanks are moved slightly apart to separate the gum on one blank from the gum on the adjacent blanks of the lapped formation. The blanks are then conveyed through a drying zone at the lower portion of the machine, and which usually extends from one end thereof to the other. Heretofore, the simplest method of conveying the blanks through the drying zone was between endless fabric belts, usually of cotton material. The belts were arranged in upper and lower pairs, so that the lower run of the upper belts cooperated with the upper run of the lower belts to grip the side flap portions of the blanks therebetween, and a strand was used to support the gummed side of the sealing flap portions. The difiiculties of such an arrange ment are that the fabric belts stretch under tension and vary in thickness, so that it is impossible to maintain uniform grip on the blanks. Change in spatial relationship of the blanks is not permissible at high speed. It is obvious that this may lead to serious jamming in subsequent operating sections of the machine.

Another difiiculty is that the strand which supports the sealing flaps marks the freshly applied gum. Another difiiculty is that it is very diificult to run envelopes with short side flaps, using cotton belts. A further difiicu-lty is that because of the expense and complication of supporting numerous guide rollers, the runs of the belts are allowed to take the form of catenaries. Therefore, to allow room for the belts, the height of the machine required an operators platform along the length of the machine, so that the operator could reach and service the operating mechanisms at the top of the machine.

Machines of lower height have been constructed by using a single set of chain belts wherein the links of the chain are provided with clips for securing the blanks, but these clips must be used in great number and they are easily deformed, requiring constant inspection and replacement. They are also apt to mark and damage the blanks.

It is the principal object of the present invention to provide blank transporting apparatus that eliminates the difiiculties of previous structures.

Other objects of the invention are to provide means for effecting a positive clamping or gripping action without marking or damaging the blanks; to provide means having such a high coefficient of friction that it is unnecessary to support the midportions of the blanks during the drying process; to provide blank carrying means whereby the blanks are carried in a linear path through the drying section; to provide a blank transporting means which simplifies the addition of new sections in the envelope making machine; to provide a blank transporting means of simple construction in which the active runs of the belts are guided by rails; to provide transporting means which hold the blanks gently yet firmly at high speeds; to provide trated in FIG. 1.

Bfillfil Patented Feb. 20, 1952 transporting means in the form of relatively non-stretchable chains; and to provide gripping pads which are preferably incorporated in the structure of the chains.

In accomplishing these and other objects of the invention as hereinafter pointed out, we have provided improved structure, the preferred form of which is illustrated in the accompanying drawings, wherein:

FIG. 1 is a longitudinal section on the line 1--1 of FIG. 2 of a tranportation apparatus for conveying envelope blanks through the drying zone of an envelope making machine to dry gum on the sealing flap portions of the blanks, the section being shortened to permit illustration thereof ona larger scale.

FIG. 2 is a cross section on the line 2--2 of FIG. 1.

FIG. 3 is a plan view of the lower chain belt and the upper feed and discharge belts at the ends of the drying section.

FIG. 4 is a fragmentary perspective view of a modified form of the upper chains, which utilizes pads with crowned gripping faces.

FIG. 5 is a perspective view of the end of one of the guide rails.

FIG. 6 is a diagrammatic underneath view of the envelope blanks, on smaller scale, showing separation of the gum on the sealing flaps.

Referring more in detail to the drawings:

l and 2 designate upper and lower pairs of belts which carry blanks a in overlapped, slightly stepped formation from a seal flap gumming device (not shown) of an envelope making machine to the drying section 3 of the machine. The belts composing each pair of belts are spaced apart to engage the end flap portions b and c of the blanks a with the gum on the sealing flap portions facing outwardly and downwardly at the delivery ends of the belts. At the delivery ends of the belts, the belts 1 have substantially horizontal runs 4 that cooperate with corresponding horizontal runs 5 of the outer belts 2 to carry the blanks a in alignment with the path of the blanks through the drying section 3, as later described.

The horizontal runs 5 are longer than the horizontal runs 4 and are guided over rollers 6. Rollers '7 which guide the horizontal runs 4 are, therefore, offset from the rollers 6 for accommodating pressure rollers 8 to facilitate delivery of the blanks at the same speed and lapped relation as during application of the gum to the sealing flaps.

In order to separate the gum on the respective blanks, the blanks must be slightly separated prior to their passage through the drying zone. This is effected by rollers 9 and it) that operate at a higher surface speed than the pressure rollers 8. The blanks are removed from the drying section between belts 11 and 12 and a center belt 13 that carry the blanks to the sections of the machine where the blanks are converted into envelopes.

The structure thus far described is substantially conventional and specifically forms no part of the present invention, the present invention pertaining primarily to an apparatus for transporting or conveying the blanks through the drying section 3 and the combination therewith of the mechanisms thatcarry the blanks to and from the drying section, as now to be described.

The apparatus for conveying the blanks through the drying section is generally designated 14 and comprises a lower pair of endless chains 15 and 16 that operate over pairs of sprockets 17 and 18 carried by shafts 19 and 2!) at the respective ends of the drying section 3, as best illus- "ihe transporting apparatus also includes an upper pair of chains 21 and 22 operating over pairs of sprockets 23 and 24 carried on shafts 25 and 2rd inset from the shafts l9 and 26, whereby the upper chains 21 and 22 are of shorter length than the lower chains 15 and 16 to provide spaces at the ends of the lower chains for feed or guide rollers 27 and 28 to facilitate entrance and exit of the blanks a to and from engagement with the upper and lower chains 15-16 and 21-22.

The chains 15-16 and 2122 are of substantially the same construction, in that they include side links 29 of ordinary construction that connect links 30 of a form to carry gripping elements 31. The links 3% have sides 32 and 33 interconnected by webs 34 (FIG. 4) to carry the gripping elements 31. The gripping elements 31 are fixed to the webs, for example by vulcanizing them to the webs 34. The links are interconnected by transverse pins 35 carrying rollers 36 substantially corresponding to the pins and rollers of conventional roller type chains. (The gripping elements 31 comprise resilient blocks or pads 37 of a rubber or similar synthetic material that does not mark the blanks a when the blanks are engaged thereby.

The pads 37 have base portions 38 of a width and length substantially corresponding to the webs 34 and preferably outwardly converging sides 39 and 40 joining with contact faces 41. The ends 42 and 43 of the blocks or pads may extend at right angles from the plane of the base portions 38 to provide clearance 44 between the respective blocks or pads when the links are connected together by the pins 35. The faces 41 of the blocks of the upper chains 21-22 may be slightly crowned in the longitudinal direction of the chains, as shown in FIG. 4, but the pads of the lower chains are preferably hat, to constitute linear supports for the side flap portions b and c of the blanks a when engaged by the pads of the upper chains.

When the chains are mounted on the pairs of sprockets 17-18 and 23 24, the lower runs 45 of the upper chains and the upper runs 46 of the lower chains are in registry and are retained in linear paths by pairs of guide rails 47 and 48. The guide rails 47 and 48 are preferably of channel cross section to provide side flanges 49 and t and a web 51 having a width to accommodate the links of chains therebetween, as best shown in FIG. 2, and the midportions of the webs have longitudinal ribs or tracks 52 for contact by the rollers 36 of the chains, whereby the frictional contact faces 41 of the resilient pads are supported in linear alignment substantially along the length of the guide rails to provide substantially equal pressure on the blanks as they are being carried through the length of the drying section of the envelope making machine.

In order that the guide rails may be as long as possible, the ends thereof are provided with slots 53 in registry with ribs or tracks 52, as best shown in FIGS. 1 and 5, and the ends of the ribs or tracks are shaped to provide ramps 54 to facilitate contact of the rollers with the ribs or tracks as the links with the pads move around the sprockets and onto the tracks. In order to facilitate entrance of the blanks between the pads of the chains and exit of the blanks therefrom, the guide rails 47 supporting the upper runs of the lower belts are preferably supported at heights relative to the axis of the sprocket shafts, so that as the blocks approach the end of the guide rails and the rollers move up the ramps at the forward end of the guide rails, the contact faces 41 of the lower pads are preferably tilted at a slight angle, as indicated at 55, FIG. 1, and so that the pads, as they leave the ends of the guide rails, move away from contact with the blanks and thereby avoid any possibility of marking the blanks.

The upper guide rails 48 are resiliently backed by springs 56 to press the pads on the lower run of the upper chains into contact with the blanks, to cooperate with the lower pads in gripping the blanks therebetween and carrying the blanks firmly through the drying section. The lower rails 47 are rigidly supported on brackets 57 carried by supports '58 that extend laterally and which are in turn carried by brackets 5? having internally threaded sleeve portions 60 carried on threaded portions 61 on a transverse shaft 62. The transverse shaft may be suitably mounted on the side frames of the envelope machine so that it may be rotated to adjust the guide rails according to the size of the envelope blanks, it also being understood that the sprockets 17-18 and 23-44 are also adjustable on their shafts 19-20 and 25-26, as will be apparent to those skilled in the art of envelope making machines. The springs 56 may be backed by arms 63 that are also adjustable with the guide rails.- In order to support the upper runs of the upper chains, the sleeve portions '60 of the main brackets 59 carry laterally extending shafts 64 mounting idler sprockets 65, as best shown in FIGS. 1 and 2. To support the lower runs of the lower chains, the supports 58 may carry rollers .66, also shown in FIGS. 1 and 2. It is obvious that as many of the main supporting brackets and transverse shafts 62 may be used as are necessary to carry the guide rails, idler sprockets 65 and rollers 66.

The drying medium used in the drying section of the machine may be heated air that is conducted along the length of the drying zone by means of a duct 67 and discharged in contact with the gummed areas of the blanks through perforations 68 in the upper portion of the duct, as shown in FIG. 2.

Assuming that the machine is in operation and that one of the sprocket shafts 25 or 26 and 19 or 20 is being driven to actuate the upper and lower pairs of transport chains at the same linear speed through the drying section, blanks are delivered from the gnmming roll between the runs 4 and 5 of the belts 1 and 2 in lapping fanned relation, as shown at the lefthand side of FIG. 6, with the gum forming a continuous band. Upon contact with the rollers 9 and 10, the blanks are moved apart as shown at the righthand side of FIG. 6, to separate the gum on the respective seal flap portions of the blanks. The blanks are then fed onto the pads on the forward end of the upper run of the lower belts with the aid of the feed rollers 27. The blanks then enter the space that is formed between the horizontal pads on the upper runs of the lower belts and the pads of the upper chains as they move successively into position to form the lower horizontal runs of the upper chains, to cooperate with the pads on the upper runs of the lower chains to grip the blanks as shown in FIG. 1. With continued movement of the belts, the links carrying the pads enter the channel shaped guides with the rollers of the chain bearing in rolling contact with the tracks 52 of the guide rails, so that the pads continue the grip on the blanks and pre vent any relative movement thereof during transfer of the blanks through the drying section. Upon reaching the end of the upper pairs of chains, the links carrying the pads move around the sprockets 24 to free the blanks, so that the blanks may be discharged from off the upper run of the lower chains in cooperation with the feed rollers 23, to feed the blanks under the lower run of the center belt 13 and between the upper and lower pairs of offtake belts 12 and 11 respectively to carry the dried blanks to the envelope converting mechanisms of the machine.

From the foregoing, it is obvious that we have provided a substantially nonstretchable means for transporting the blanks in a linear path through the drying zone, and that the lapped blanks are gripped and held together between the pads on the chains so that the blanks cannot shift their relative positions during transport through the drying section of the envelope making machine. It is also obvious that the rubber pads have a high coefficient of friction, so that the contact faces thereof firmly grip the blanks to support the gummed portions of the blanks in taut condition across the space between the chains without intermediate supports that might interfere with the gum or drying thereof.

Another advantage is that blanks of thin and fragile materials may be conveyed without slipping or damage thereto.

What we claim and desire to secure by Letters Patent is:

1. Apparatus for conveying envelope blanks in lapped and slightly stepped relation through a drying section of an envelope making machine to expose gummed portions of the blanks to a drying medium, said apparatus including a lower pair of endless chains each composed of interconnected links, blocks of resilient material carried on said links and having frictional faces for supporting contact with portions of said blanks laterally and outwardly of the gummed portions, means for supportingsaid lower pair of chains to provide upper runs for continuous movement through said drying section in laterally spaced apart parallel relation and providing a substantially uninterrupted space between said upper runs at least corresponding in width to the width of the gummed portions of the blanks for the full length of the drying section for free access of the drying medium to said blanks, separate longitudinal guide means below each of said upper runs for retaining the frictional faces of said blocks in linear alignment for supporting said lateral portions of the blanks thereupon, an upper pair of endless chains having interconnected links, similar blocks of resilient material on the links of the upper chains and having frictional faces for pressing contact with the lateral portions of the blanks, means for supporting the upper pair of chains in correspondingly spaced apart relation and to provide lower runs in registry with and extending longitudinally above the upper runs of the lower chains to operate at the same linear speed, guide means for backing said lower runs for pressing the fractional faces of said blocks on the links of the lower runs into contact with the portions of the blanks supported upon the frictional faces of the blocks on the links of the upper runs of the lower chains for gripping the lateral portions of the blanks between said frictional faces for maintaining the gummed portions of the blanks in substantially taut condition across said space solely by the gripping action on said lateral portions of the blanks while the blanks are being carried through the drying section, and means for delivering the blanks in said lapped relation onto said frictional faces of the blocks of the upper runs of the lower chains.

2. Apparatus for conveying envelope blanks in lapped and slightly stepped relation through a drying section of an envelope making machine to expose gummed portions of the blanks to a drying medium, said apparatus including a lower pair of endless chains each composed of interconnected links, blocks of resilient material carried on said links and having frictional faces for supporting contact with portions of said blanks laterally and outwardly of the gummed portions, means for supporting said lower pair of chains to provide upper runs for movement through said drying section in laterally spaced apart parallel relation and provide a substantially uninterrupted space between said upper runs at least corresponding in width to the width of the gummed portions of the blanks for the full length of the drying section for access of the drying medium to said blanks, separate longitudinal guide means below each of said upper runs for retaining the frictional faces of said blocks in linear alignment for supporting said lateral portions of the blanks thereupon, said longitudinal guide means having forward ends of a shape to tilt the links as the links engage said guide means to facilitate passage of the blanks onto the frictional faces, an upper pair of endless chains having interconnected links, similar blocks of resilient material on the links of the upper chains and having frictional faces for contact with the lateral portions of the blanks, means for supporting the upper pair of chains in correspondingly spaced apart relation to provide lower runs in registry with and extending longitudinally above the upper runs of the lower chains to operate at the same linear speed, guide means for backing said lower runs for pressing the frictional faces of said blocks on the links of the lower runs into pressing contact with the portions of the blanks supported upon the frictional faces of the blocks on the links of the upper runs of the lower chains for gripping the lateral portions of the blanks between said frictional faces for maintaining the gummed portions of the blanks in substantially taut condition across said space solely by the gripping action on said lateral portions of the blanks while the blanks are being carried through the drying section, and means for delivering the blanks in said lapped relation onto said frictional faces of the blocks of the upper runs of the lower chains.

3. Apparatus for conveying envelope blanks in lapped and slightly stepped relation through a drying section of an envelope making machine to expose gummed portions of the blanks to a drying medium, said apparatus including a lower pair of endless chains each composed of interconnected links, blocks of resilient material carried on said links and having frictional faces for supporting contact with portions of said blanks laterally of the gummed portions, means for supporting said lower pair of chains to provide upper runs for continuous movement through said drying section in spaced apart parallel relation and provide a substantially uninterrupted space between said upper runs at least corresponding in width to the width of the gummed portions of the blanks for the full length of the drying section for access of the drying medium to said blanks, separate longitudinal guide means below each of said upper runs for retaining the frictional faces of said blocks in linear alignment for supporting said lateral portions of the blanks thereupon, an upper pair of endles chains having interconnected links, similar blocks of resilient material on the links of the upper chains and having frictional faces for pressing contact with the lateral portions of the blanks, means for supporting the upper pair of chains to provide lower runs in registry with and extending longitudinally above the upper runs of the lower chains to operate at the same linear speed, said upper linear runs of the lower chains being of longer length than the linear lower runs of the upper chains to project forwardly from under linear runs of the lower chains, feed wheels cooperating with the projecting ends of said upper runs of the lower chains for holding the blanks in position to be engaged by the blocks of the upper chains, guide means for backing said lower runs for pressing the frictional faces of said blocks on the links of the lower runs into contact with the portions of the blanks supported upon the frictional faces of the blocks on the links of the upper runs of the lower chains for gripping the lateral portions of the blanks between said frictional faces for maintaining the gummed portions of the blanks in substantially taut condition across said space solely by the gripping action on said lateral portions of the blanks while the blanks are being carried through the drying section, and means for delivering the blanks in said lapped relation onto said frictional faces of the blocks at the projecting ends of the upper runs of the lower chains.

4. Apparatus for conveying envelope blanks in lapped and slightly stepped relation through a drying section of an envelope making machine to expose gummed portions of the blanks to a drying medium, said apparatus including a lower pair of endless chains each composed of interconnected links, blocks of resilient material carried on said links and having frictional faces for supporting contact with portions of said blanks laterally and outwardly of the gummed portions, means for supporting said lower pair of chains to provide upper runs for continuous movement through said drying section in laterally spaced apart parallel relation and providing a substantially uninterrupted space between said upper runs at least corresponding in width to the width of the gummed portions of the blanks for the full length of the drying section for free access of the drying medium to said blanks, separate longitudinal guide means below each of said upper runs for retaining the frictional faces of said blocks in linear alignment for supporting said lateral portions of the blanks thereupon, an upper pair of endless chains having interconnected links, similar blocks of resilient material on the links of the upper chains and having frictional faces for pressing contact with the lateral portions of the blanks, means for supporting the upper pair of chains to provide lower runs in registry with and extending longitudinally above the upper runs of the lower chains, said upper runs of the'lower chains being of longer length than the lower runs of the upper chains to project beyond the respective ends of the lower chains, feed wheels cooperating respectively with the projecting ends of said upper runs of the lower chains for facilitating entrance and exit of the blanks, guide means for backing said lower runs for pressing the frictional faces of said blocks on the links of the lower runs into contact with the portions of the blanks supported upon the frictional faces of the blocks on the links of the upper runs of the lower chains for gripping the lateral portions of the blanks between said frictional faces for maintaining the gummed portions of the blanks in substantially taut condition across said space solely by the gripping action on said lateral portions of the blank while the blanks are being carried through the drying section, and means for delivering the blanks in said lapped relation onto said frictional faces of the blocks at the projecting ends of the upper runs of the lower chains.

Novick Nov. 13, 1956 Daniels et al. Nov. 20, 1956

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