US2489210A

US2489210A - Apparatus for adhesively uniting sheet materials

Info

Publication number: US2489210A
Application number: US714756A
Authority: US
Inventors: Norman E Weeks
Original assignee: Bemis Brothers Bag Co
Current assignee: Bemis Brothers Bag Co
Priority date: 1946-12-07
Filing date: 1946-12-07
Publication date: 1949-11-22
Anticipated expiration: 1966-11-22

Description

N. E. WEEKS Nov. 22, 1949 APPARATUS FOR ADHESIVELY UNITING SHEET MATERIALS 4 SheetsSheet 1 Filed Dec. '7, 1946 FIG. I.

4 Sheets-Sheet 2 N. E. WEEKS APPARATUS FOR ADHESIVELY UNITING SHEET MATERIALS Filed Dec. '7, 1946 Nov. 22, 1949 mm u r o 1: W O. Q Q RE, WW. t. V E u lw a I I w w n H @m F Hm mm Q Q 0 3 ME fl Q \Q Q n I 1.H. HIP l m N H Q 6 ti Q Lx kw Nov. 22, 1949 N E. WEEKS 2,489,210

APPARATUS FOR ADHESIVELY UNITING SHEET MATERIALS Filed Dec. 7, 1946 4 Sheets-Sheet 5 III N. E. WEEKS APPARATUS FOR ADHESIVELY UNITING SHEET MATERIALS Filed Dec. 7, 1946 4 Sheets-Sheet 4 mm m: i llmwllll. 13?! My Q WW d Q mm a z 3 a T I l I b I i IIII 1 1 E W i|1l I 2| Q 1 1 mm. m3 mu um Q l ma 7 m k R .8 I ia Q 3 z :Q l I I Q s E .3 w 5 w Q 5 m8 m E E \w E Q Patented Nov. 22,1949

APPARATUS FOR ADHESIVELY UNITING SHEET MATERIALS Norman E. Weeks, Indianapolis, Ind., asslgnor to Bemls Bro. Bag caigpany, St. Louis, Mo., a corporation of Misso Application December 7, 1946, Serial No. 714,756

Claims. 1

This invention relates to apparatus for adhesively uniting sheet materials, and more partic- -ularly to apparatus for adhesively securing valve sleeves to bag valves.

Among the several objects of the invention may be noted the provision of an improved apparatus for adhesively uniting sheet materials. particularly valve sleeves in bag valves, by means of thermoplastic adhesive; the provision of apparatus of this classadapted to accomplish accurate and effective securement of valve sleeves to bags in minimum time so as to achieve a high production rate of valved bags per operator; and the provision of apparatus for this purpose which requires no special skill on the part of the operator and which may be reliably and safely employed. Other objects will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combination of elements, features of construction and arrangements of parts which will be exemplified in the structures hereinafter Fig. 3 is a semi-diagrammatic plan view of the apparatus of this invention also illustrating the 'step of uniting the sleeve and bag; 1 Fig. 4 is a view of a completed v-alve bag;

Fig. 5 is an enlarged detail'plan view of the apparatus, certain parts being broken away;

Fig. 6 is a section taken on line 6-6 of Fig. 5;

Fig. 7 is a section taken on line 1-1 of Fig. 5; and,

Fig. 8 is a side elevation as viewed from the right of Fig. 5.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now particularly to Figs. 1-3, Fig. 1 illustrates a textile fabric bag I and a valve sleeve 3 which are to be adhesively joined with the apparatus of this invention to form a valve bag. At this stage of the process in the manufacture of the valve bag, the mouth 5 of the bag is open. The sleeve 3 comprises a rectangular paper sheet, the short sides of which are caused to extend longitudinally with respect to the h The sleeve. is creased on its longitudinal center line I and has a slit 9 extending inward from its outer edge upon the center line. The sleeve is also prepared with a transverse stripe of thermoplastic adhesive II by means of which it is to be adhesively secured to the bag.

To form a valve bag, the sleeve 3 is folded upon the crease with adhesive l I on the outside of the folded sleeve. It is then inserted into the mouth of the bag, being fitted in a corner thereof as illustrated in Fig. 2, with the stripe of adhesive engaging the inside wall of the bag adjacent its mouth and with the slitted. portion of the sleeve extending outward. This bag and sleeve assembly, hereinafter referred to'as the work, is then fed through a heated presser unit I3 (Fig. 3) in a direction parallel to the edge of the bag mouth at such a relatively low rate of speed as to permit the adhesive to soften and secure the sleeve to the bag under pressure. It will be noted from Fig. 3 that the aforesaid corner of the bag is introduced first into the presser unit. It will also be noted that once this corner of the bag has been fed through the presser unit there remains a substantial portion of the work,

designated X in Figs. 2 and 3, in which there is no adhesive to be acted upon. Consequently, there is no necessity for feeding this portion of the work through the presser unit at the same relatively low rate of speed as said corner. In order to clear the bag rapidly from the presser unit once its corner issues therefrom, so that the operator may soon feed another bag and sleeve assembly thereto, the apparatus of this invention further includes means for pulling the bag through the unit at considerably higher speed than the aforesaid rate so as quickly to eject the completed product. Thus, that limited portion of the bag and sleeve assembly wherein adhesive is to be softened is fed through the presser unit slowly enough to permit the adhesive to soften, and the remainder of the bag is pulled rapidly out of the presser unit.

The resultant product, which corresponds to Fig. 2 except that the sleeve 3 is now aiiixed in the corner of the bag at its mouth, is subseouently formed into a valve bag illustrated in Fig. 4 by tucking in the sleeve-lined corner to form a sleeve-lined valve flap. A seam i5 is finally stitched across the mouthof the bag to close it. This forms a valved bag having a valve inlet ll, of which the sleeve liner forms an inward extension, the bag being adapted to be filled with comminuted or pulverulent material by inserting a filling spout through the valve inlet. When the bag is filled, the pressure of the filling I s 3" closesthevalveand oftheflllingi'romthebag,aswillbereadily understood from the art. Generally, as stated. the apparatus of thisinvention embodies means for feeding the work' through the presser unit I3 at the rate of speed such as to permit the adhesive to soften. This means comprises two sets I 3 and II of continuously driven draw rolls which are driven at such a speed as to advance the work at the aforesaid heated presser head 25 and an upper heated presser head 25 which is spring-biased into engagement with the lower head. The lower head is fixed upon the end of a supporting arm 21 which extends outward and upward from the base plate 29 of the apparatus. It comprises a chan nel bar 3| which is secured by screws 33 to the end of arm 21 with the channel opening upward. Disposed within the channel is an electrical resistance strip heating element 35. A layer 31 of suitable heat insulating material, such as asbestos, is disposed between the heating element and the channel. A steel plate 39 is secured by screws 4I (Fig. 6) to the channel over the heating element. This plate has a smooth upper surface which forms the lower pressurereceiving surface of-the presser unit I3. Current is supplied to the heating element 35 by conductors 43.

The upper presser head 25 is similar to the lower head and comprises a channel bar 45 fixed upon the lower end of rods 41 with the channel opening downward. Disposed within the channel is an electrical resistance strip heating element 49, a layer i of heat insulating material being disposed between the heating element and the channel. A steel plate 53 is secured by screws 55 to the channel over heating element 49. This plate has a smooth lower surface which forms the pressure-applying surface of the presser unit I3.

Current is supplied to heating element 49 by flex ible conductors 51.

The upper ends of rods 41 are slidable in apertures in a plate 59 carried by a supporting arm 5| extending outward from a pedestal 63 on base plate 29. The rods are biased downward by compression springs 95 reacting between the under surface of the plate 59 and nuts 61 threaded on the rods to bias the upper presser head into engagement with the lower presser head. The bias is adjustable by means of nuts 99 threaded onthe ends of rods 41 extending through plate 59.

From the above it will be clear that work may be fed between the heated pressure plates 39 and 53, as illustrated in Fig. 3, to soften the thermoplastic adhesive stripe II on the valve sleeve and to press the bag and valve sleeve firmly together to effect adhesive affixing thereof. The upper plate 53 rises againstthe bias of springs 55 in accordance with the thickness of the work. The work is fed through the presser unit from right to left as viewed in Fig. 6,.it will be noted that plates 39 and 53 diverge at their right handends to form an inlet throat II.

The work is fed between the presser heads by auaaio thereby prevents leakage draw roll shafts I1 and 19, respectively. The upper shaft. I1 is Journalled in vertically sliding bearings 9| in the aforesaid pedestal 93 and in another pedestal 33- mounted on base plate 29 suitable guideways in the pedestals and arebiased downward by compression springs 85. Lower shaft 19 is jdurnalled in fixed bearings 91 in the pedestal. The arrangement is such that the axially spaced knurled flange portions 99 of the upper draw roll I3 are biased into engagement with the axially spaced knurled flange portions 9| of the lower. draw roll I5, and the upper draw roll may rise as work is fed through the apparatus in accordance with thethickness of the work. The nip of draw rolls I3 and I5 is adjacent the forward end of inlet throat II of the presser unit and the pass plane of these rolls is substantially coincidental with the mating plane of the pressure surfaces of plates 39 and 53 (Fig 6).

The set 2| of draw rolls is similar to set I9, comprising upper and lower spool-shaped rolls 93 and mounted upon upper and lower draw roll shafts 91 and 99, respectively. Upper shaft 91 is journalled in vertically sliding bearings IIII, corresponding to bearings 9|, in pedestals 63 and 83. These bearings are biased downward by springs I93 corresponding to the springs 85. Lower shaft 99 is journalled in fixed bearings I95 in the pedestals; Thus, the knurled flange portions IIll of the upper draw roll 93 are biased downward into engagement with the knurled flange portions I09 of the lower draw roll 95, and the upper draw roll may rise as work is fed through the apparatus in accordance with the thickness of the work. The nip of draw rolls 93 and 95 is some distance rearward of the exit end of the presser unit and the pass plane thereof is substantially coincidental with the plane of the pressure surfaces of plates 39 and 53. It will be noted that the presser unit is disposed within the recesses of the draw rolls between their flange portions.

Each of the aforesaid draw rolls I3, 15, 93 and 95 is adapted to be driven by its respective shaft through an overrunning clutch in order to permit each draw roll to be rotated faster than its shaft when required. As illustrated particularly in Fig. 6, each of thedraw rolls is rotatably mounted upon the end of its shaft. A ratchet I I I is fixed upon each draw roll shaft adjacent the draw roll thereon. Pivotally mounted upon the inside flange portion of each draw roll is a pawl II3 biased into engagement with the respective ratchet by a spring I I5 carried by said flange portion. The arrangement of the ratchet and pawl mechanism is such that when the draw rolls are rotated in the forward direction at a speed faster than the speed of their respective shafts, the draw rolls may overrun their shafts, the pawls ratcheting over the ratchet teeth during such overrunning action.

The set of pulling rolls comprises an upper knurled roll II! and a lower knurled roll II9. Upper roll I I1 is fixed upon the end of a shaft I2I journalled for rotation in vertically slidable bearings I23 in pedestals 63 and 93. These bearings are guided for vertical sliding movement in suitable guideways in the pedestals and are biased downward by compression springs I25. The lower pulling roll H9 is fixed on the end of a shaft I21 which is joumalled in fixed bearings I29 in the the aforesaid sets ll-wand II of draw rolls. The set I9 comprises upper and lower spool-shaped rolls 'l3and 15 mounted upon upper and lower 5. pedestals. The arrangement is such that the upper pulling roll II! is biased into engagement with the lower pulling roll III. It will be noted that the upper pulling roll may rise as work is fed through the apparatus in accordance with the thickness of the work. The pulling rolls Ill and H9 are located in such position that the work issuing from between the pressure plates 39 and 53 of the presser unit is picked up in the nip of these rolls and fed outward (to the left as viewed in Fig. 6). Pulling rolls Ill and H9 are of greater diameter than the draw rolls I3, I5, 93 and 95 and their peripheral speed is greater than that of the draw rolls to pull the work through the apparatus at a higher rate of speed than the rate at which the work is fed forward by the draw rolls.

Suitable driving means is provided for driving the draw roll and the pulling roll shafts. As illustrated in Fig. 3, a motor I3I is coupled through a speed reducer I33 and a belt drive I35 to drive the upper pulling roll shaft Hi. The upper pulling roll shaft is coupled to drive the lower pulling roll shaft I21 at the same speed by means of intermeshing gears I31 and I39 fixed on the upper and lower shafts HI and I21, respectively. The upper pulling roll shaft I2I is coupled to drive the upper draw roll shaft 11 by a speed-reducing chain and sprocket drive I. The upper draw roll shaft 11 is coupled to drive the upper draw roll shaft 91 at the same speed by means of a chain and sprocket drive I43. The upper draw roll shaft 11 is coupled to drive the lower draw roll shaft 19 at the same speed by means of gears I41 and I59, and the upper draw roll shaft 91 is coupled to drive the lower draw roll shaft 99 at the same speed by gears I5I and I53.

The apparatus also includes means for guiding the work into the presser unit and into the nip of the set I9 of drawing rolls. This means comprises a table I55 supported upon the base plate 29 of the apparatus with its upper surface substantially coplanar with the mating plane of the pressure plates 39 and 53 and the pass plane of the draw and pulling rolls. A guide bar I5I is transversely adjustably mounted upon the table. Screws I59 extend upward. from the table through slots in slotted fingers I 5| on the bar, and the bar is clamped in adjusted position by wing nuts I63 threaded on the screws.

The operation of the apparatus is as follows:

The guide bar 151 is initially adjusted relative to the longitudinal center line of the presser unit I3 so that the distance from the face of the bar I to this center line is equal to the distance Y from the outer edge of the valve sleeve 3 to the center line of the stripe II of adhesive thereon. Current is supplied to heaters 35 and 49 to heat the pressure plates to a temperature sufllcient to soften the adhesive consistent with the rate of speed at which the work is fed therebetween. The motor i3l is energized to drive the draw rolls I3, I5, 93 and 95 and pulling rolls III and H9 continuously. 4 g

The operator inserts the bag and valve sleeve assemblies illustrated in Fig. 2 successively into the inlet throat II of the presser unit in the manner shown in Fig. 3, employing the guide bar I51 as a guide for the outer edge of the valve sleeve. The work is inserted into the throat II and between pressure plates 39 and 53 a sufflcient distance to introduce it into the nip of the draw rolls I3 and I5, whereupon these draw rolls (and subsequently the draw rolls 93 and 95) function to feed the work forward between the plates at a parent that the plates 33 and 53 must be main speed equal to the nominal peripheral speed of the draw rolls. With the outer edge of the valve sleeve in engagement with guide bar I51, registration of the stripe II of adhesive between the pressure plates is assured. As the work is fed between the pressure plates, the adhesive is softened by heat and the plates press the walls of the bag and the valve sleeve firmly together to efiect adhesive ailixing thereof.

As the forward edge of the work leaves the presser unit, it is caught in the nip of pulling rolls Ill and H9 and the work is pulled through the presser unit at substantially higher speed and delivered from the apparatus to a station. where the subsequent operation of tucking in the corner of the bag is performed. During pulling of the work by pulling rolls III and H9, draw rolls I3, I5, 93 and 95 are driven by the work in the forward direction at a greater speed than that nominally imparted thereto by their respective drive shafts. During this phase of the operation, the draw rolls overrun their shafts, this being permitted by the pawl-and-ratchet overrunning clutches.

The feature of pulling the work through the presser unit by means of the high-speed pulling rolls is of considerable importance inasmuch as it reduces to a minimum the time required to feed the work through the apparatus. Note that once the corner of the bag having the valve sleeve therein has been fed through the presser unit, there remains the considerable length X of the work to be fed although no heating and pressing operation needs to be performed thereon. Pulling rolls III and [I9 function to pull this length of the. work rapidly through the apparatus after the corner has passed through the pressure plates 39 and 53, and thus the work is delivered away from the apparatus as rapidly as possible and its output is greatly increased, particularly on wide bags. It will also be noted that it is important to feed that portion of the work including the stripe II of adhesive between the pressure plates at a rate of speed consistent with the temperature of the plates to enable suflicient softening of the adhesive to effect adhesion of the valve sleeve and bag. The relatively low speed drive of the draw rolls to accomplish this is effected by the speed-reducing drive I for the draw rolls.

Thus, the operator may rapidly feed one bag and valve sleeve assembly after the other through the apparatus, inasmuch as each assembly is fed through the apparatus in minimum time. The valve sleeves are effectively secured to the bags in the course of their passage between the pressure plates 39 and 53' due to the heating and softening of the thermoplastic adhesive II by the presser unit and the application of pressure to the work. It will be noted that the work is gripped between the knurled flange portions 39 and 9| of 'draw rolls I3 and I5 and between the knurled flange portions I01 and I99 of draw rolls 93 and 95 in its passage through the apparatus. This permits the portion of the work between the flange portions of the draw rolls to pass between the pressure plates 39 and 53, and be drawn evenly therethrough.

It will be understood that the heaters 35 and 49 are preferably under the control of a suitable thermostatic control device responsive to plate temperature so as to maintain plates 39 and 53 substantially at the temperature required to soften the adhesive for the rate of speed at which the work is fed between the plates. It will. be ap- 7 tained at higher temperatures for higher speeds of the draw rolls in order to soften the adhesive in the course of the passage of the work between the plates.

While the apparatus of this invention has been particularly described herein with reference to its use for securing valve sleeves to bags, it will be understood that it is readily adaptable for use for securing other sheet materials by means of thermoplastic adhesive over a limited portion of the area thereof.

Cross reference under Rule 43 is made to applicant's divisional application entitled Method of adhesively uniting sheet materials, Serial No. 53,717, filed October 9, 1948.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the class described, a pair of cooperating spool-shaped draw rolls having axially spaced flange portions adapted to grip and feed work, a pair of relatively movable heated pressure plates biased into pressure engagement, said plates being disposed between said flange portions with the plane of engagement of the plates substantially coincidental with the pass plane of said rolls.

2. In apparatus of the class described, a pair of cooperating spool-shaped draw rolls having axially spaced flange portions adapted to grip and feed work, a pair of relatively movable heated pressure plates biased into pressure engagement, said plates being disposed between said flangeportions with the plane of engagement of the plates substantially coincidental with the pass plane of said rolls, said draw rolls being relatively transversely movable and being biased into pressure engagement.

3. In apparatus of the class described, a pair of cooperating spool-shaped draw rolls having axially spaced flange portions adapted to grip and feed work, a pair of relatively movable heated I pressure plates biased into pressure engagement, said plates being disposed between said flange portions with the plane of engagement of the plates substantially coincidental with the pass plane of said rolls, means for driving said draw rolls at a predetermined speed, overrunning clutch mechanism in said drive means permitting said rolls to run faster than the drive means, a drive, and a work puller adapted to grip and feed forward work issuing from said pressure plates at a speed higher than said predetermined speed.

4. In apparatus of the class described, a pair of cooperating spool-shaped draw rolls having axially spaced flange portions adapted to grip and feed work, a pair of relatively movable heated 8 a speed higher than said predetermined speed.

' said work puller comprising pulling rolls adapted to pull work through said pressure plates at said higher speed.

5. Apparatus for adhesively securing valve sleeves in bags comprising at least one set of cooperating spool-shaped draw rolls having axially spaced flange portions adapted to grip and feed a bag and sleeve assembled with thermoplastic adhesive therebetween, a pair of relatively movable pressure plates biased into pressure engagement, said plates being disposed between said flange portions with the plane of engagement of the plates substantially coincidental with the pass plane of said rolls, heaters for heating said plates to a temperature suflicient to soften said adhesive in the course of its passage between said plates, means for driving said draw rolls at a predetermined speed, overrunning clutch mechanism in said drive means permitting said rolls to run faster than the drive means, and pulling rolls adapted to grip a bag and sleeve assembly issuing from said pressure plates to pull said assembly through said plates at a speed higher than said predetermined speed.

6. In apparatus of the class described, a heated presser unit for applying heat and pressure to an assembly of sheet materials having a thermoplastic adhesive therebetween over a limited portion thereof, a first sheet-feeding device positioned to feed said portion of the assembly through the presser unit, means for driving said device at such a rate of speed as to permit the adhesive to soften and unite said materials over said portion under heat and pressure, overrunning clutch mechanism included in said drive means permitting said device to run faster than the drive means, and a second sheet-feeding device located to engage said portion after it issues from the presser unit and driven at a substantially higher rate of speed than the first sheet-feeding device to pull the remainder of the assembly through the presser unit at the higher rate of speed and thereby rapidly to clear the presser unit so that it may receive another assembly.

7. In apparatus as set forth in claim 6, the

presser unit comprising a pair of relatively movable heated pressure plates biased into pressure engagement. I g

8. In apparatus of the class described, a heated presser unit for applying heat and pressure to an assembly of sheet materials having a thermoplastic adhesive therebetween over a limited portion thereof, a first set of feed rolls positioned to pressure plates biased into pressure engagement,

said plates being disposed between said flange feed said portion of the assembly through the presser unit, means for driving said rolls at such a rate of speed as to permit the adhesive to soften and unite said materials over said portion under heat and pressure, overrunning clutch mechanism included in said drive means permitting said rolls to run faster than the drive means, and a second set of feed rolls located to engage said portion after it issues from the presser unit and driven at a substantially higher rate of speed than the first set of rolls to pull the remainder of the assembly through the presser unit at the higher rate of speed and thereby rapidly to clear the presser unit so that it may receive another assembly.

9. In apparatus of the class described, a heated presser unit for applying heat and pressure to an assembly of sheet materials having a thermoplastic adhesive therebetween over a limited portion thereof, a set of draw rolls comprising a pair of relatively movable'rolls biased into pressure engagement positioned to feed said portion of the assembly through the presser unit, means for driving said device at such a rate of speed as to permit the adhesive to soften and unite said materials over said portion under heat and pressure, overruning clutch mechanism included in said drive means permitting said draw rolls to run faster than the drive means, and a set of pulling rolls comprising a pair of relatively movable rolls biased into pressure engagement and located to grip said portion after it issues from the presser unit and driven at a substantially higher rate of speed than the draw rolls to pull the remainder of the assembly through the presser unit at a higher rate of speed and thereby rapidly to clear the presser unit so that it may receive another assembly.

10. In apparatus of the class described a heated presser unit comprising a pair of relatively movable heated pressure plates biased into pressure engagement for applying heat and pressure to an assembly of sheet materials having a thermoplastic adhesive therebetween over a limited portion thereof, a first set of draw rolls positioned to feed said portion of the assembly through the presser unit, means for driving said rolls at such a rate of speed as to permit the adhesive to soften and unite said materials over said portion under heat and pressure, overrunning clutch mechanism included in said drive means permitting said rolls to rim faster than the drive means, and a set of pulling rolls located to grip said portion after it issues from the presser unit and driven at a substantially higher rate of speed than the draw rolls to pull the remainder of the assembly through the presser unit at the higher rate of speed and thereby rapidly to clear the presser unit so that it may receive another assembly.

NORMAN E. WEEKS.

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

UNITED STATES PATENTS Number Name Date 1,261,055 'Pfchl Apr. 2, 1918 1,297,643 Boyer Mar. 18, 1919 1,755,926 Leguillon et a1. Apr. 122, 1930 2,093,640 Millenaar Sept. 21, 1937 2,126,908 Moore Aug. 16, 1938 2,162,230 Salfisberg June 13, 1939 2,303,087 Neller Nov. 24, 1942 2,335,190 Minich Nov. 23, 1943 2,383,849 Davies Aug. 28, 1945 2,392,695 Rohdin Jan. 8, 1946 2,410,834 Messmer Nov. 12, 1946