US3509853A - Adhesive applicator - Google Patents

Description

May 5', 1970 E. A. HARTBAUER ET AL 3,509,853

ADHESIVE APPLICAIOR Filed Aug. 7, 1967 5 Sheets-Sheet 1 FIG. FIG. l4

' INVENTORS.

ELLSWORTH A. HARTBAUER R OLF R. WEIS t W a 29 ATTORNEY ADHESIVE APPLICAT OB I 5 Sheets-Sheet 2 Filed Aug. 7. 1967 INVENTORS. ELLSWORTH A. HARTBAUER RUDOLF R. WE IS 076. (Q ATTOFf May 5, 1970 E. A. HART BAUER ET 3,509,853

ADHESIVE APPLICATOR Filed Aug. 7, 1967 5 Sheets-Sheet 3 FIG. 5

ATTORNEY y 5, 1970 E. A. HARTBAUER ET AL 3,509,853

ADHESIVE APPLICATOR 5 Sheets-Sheet 5 Filed Aug. 7, 1967 s E mam N m m W R 4 T vH T m U A @@@@@S @Q a United States Patent 3,509,853 ADHESIVE APPLICATOR Ellsworth A. Hartbauer, Concord, and Rudolf R. Weis,

Antioch, Calif assignors to Crown Zellerbach Corporation, San Francisco, Calif., a corporation of Nevada Filed Aug. 7, 1967, Ser. No. 658,762 Int. Cl. B05c 3/20 US. Cl. 118-411 13 Claims ABSTRACT OF THE DISCLOSURE An adhesive applicator wherein liquid adhesive is forced under pressure axially through a hollow stator shaft to a pair of outlet openings in the opposite side walls of a collar on the shaft. An inner wall on a rotor surrounds but is spaced from the collar to prevent excessive frictional heat rise at high speed rotation and includes a plurality of entrances, each of which sequentially during rotation is intermittently aligned with the outlet on the stator to receive an adhesive charge, the charges being forced from the entrances through individual ducts to an exterior discharge surface from which surface the adhesive is deposited on a web in a predetermined pattern as the web advances in contact with the rotor.

Background of the invention The present invention relates to apparatus for applying fluid material to a surface; and, more particularly to rotary fluid material applicators which deposit the material on a receiving surface in a predetermined pattern. Although specific reference is made hereinafter to use of the applicator mechanism of the present invention in applying adhesive to bag bottom flaps prior to folding the flaps in a bag-bottoming operation, it is to be understood that the mechanism is useful in applying fluid patterns on surfaces other than bag bottom flaps.

In US. Pat. No. 3,255,729 Weis, issued June 14, 1966, and assigned to Crown Zellerbach Corporation, the same assignee as the present invention, an adhesive applicator is disclosed which has been effectively used to apply relatively low viscosity adhesive in a pattern to bag bottoms as a part of the closing operation performed on the bag bottoms. The applicator disclosed in the patent just mentioned includes a stator element having an inlet connectable to a pressurized source of adhesive, which adhesive is forced through the stator to an outlet opening located on a surface thereof. Further in accordance with the teaching of the aforementioned patent, a rotor is rotatably mounted with respect to the stator and includes a surface having a plurality of entrance openings which surface is urged into abutment with the surface of the stator having the outlet opening. The entrance openings are positioned so as to sequentially communicate with the outlet in the stator and receive an adhesive charge therefrom. This charge passes from the entrance opening through the rotor to an exterior discharge surface having a predetermined pattern, and from the discharge surface the adhesive is applied to bag bottom flaps as the flaps are advanced in contact with the discharge surface.

While the applicator disclosed in the patent just discussed has operated satisfactorily for the purpose intended in that it has permitted relatively low viscosity adhesive to be applied to a bag bottom in a rapid and effective manner as compared to other devices heretofore known, it remains that it would be desirable to provide a device capable of Operating at even greater speeds to take advantage of the speed operating capability of other parts of present bag forming and bottoming equipment.

3,509,853 Patented May 5, 1970 Summary It is therefore an object of the present invention to provide a fluid material applicator mechanism capable of applying relatively loW viscosity fluids effectively to a surface and having capability of high operating speed, and including other advantages of long life and relatively simplified construction.

In accordance with one important aspect of the present invention, an external fluid discharge surface on a rotor is in fluid flow communication with an entrance located on an internal surface of the rotor, and the internal surface having the entrance on the rotor is spaced from a surface on a stator having an outlet which supplies adhesive to the rotor entrance only during a period of rota tion when the entrance is aligned with the stator outlet. Because of the spacing between the rotor and stator surfaces, high speed rotation is permitted Without causing any excessive frictional heat rise.

In accordance with another aspect, the stator comprises a circular hollow shaft having an enlarged collar which provides the surface having the outlet, and the rotor is generally cylindrical with an internal annular groove surrounding the collar and providing internal surfaces for the entrance openings so that seals may be provided between the rotor and stator which are essentially no larger internally than the outer diameter of the stator. The seals prevent fluid material from reaching the external surfaces of the apparatus except as desired through the discharge system provided in the rotor. The effective life of the seals is enhanced because the constructional arrangement of the rotor and stator permits the seals to occupy a sealing position between opposite surfaces where the relative rotational velocity is minimal compared to the relative rotational velocity betweenthe other opposed surfaces in the rotor and stator.

Still other aspects reside in the provision of removable outlet nozzles and in the particular duct system leading to the nozzles so that assurance is gained that each nozzle receives essentially the same adhesive charge.

Brief description of the drawing While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the present invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a diagrammatic side elevation of the drive side of the apparatus incorporating the adhesive applicator mechanism of the present invention;

FIG. 2 is an exploded view of the applicator mechanism;

FIG. 3 is a fragmentary front elevation taken along line 33 of FIG. 1 with parts broken away for convenience of illustration;

FIG. 4 is a fragmentary side elevation taken along line 4-4 of FIG. 3 with parts broken away;

FIG. 5 is a fragmentary plan elevation of drive mechanism for the adhesive applicator of the present invention;

FIG. 6 is a transverse section taken on line 66 of FIG. 4 with parts broken away;

FIG. 7 is a broken away section taken on line 7-7 of FIG. 4 to illustrate a part of the stator mounting;

FIG. 8 is a fragmentary section taken on line 88 of FIG. 6 with parts further broken away;

FIG. 9 is a radially developed elevation along line 9--9 of FIG. 8, but also illustrating the pattern on both sides of the rotor surface;

FIG. 10 is a fragmentary section taken on line 10-10 of FIG. 8;

FIG. 11 is a fragmentary section taken on line 11-11 of FIG. 8;

FIG. 12 is a fragmentary section taken on line 1212 of FIG. 10;

FIG. 13 is a sectional view of a nozzle which forms an adhesive discharge surface; and,

FIGS. 14 and 15 are plan views of a bag respectively illustrating bottom flaps thereof in open and closed position.

General description First referring to FIG. 1, there is illustrated a bag-bottoming apparatus including a drum 20 mounted for rotation about an axis defined by an axle 21. A ring gear 22 mounted on one side of the drum for rotating the drum derives its motion from a gear 23 secured at the end of the driven shaft of a drive motor 24 mounted on the floor.

Articles such as flap-equipped bags 25 are fed to the external cylindrical surface 26 of the drum by conventional conveyor means 27. In the instance of utilizing the apparatus to apply adhesive to bag flaps, paper bags 25 (FIGS. 14 and 15) having bottom flaps 28 and 29 open (FIG. 14) are advanced with the drum and between a nip or opening defined by the outer surface of the drum and the outer generally cylindrical surface of a rotating portion of an adhesive applicator 30. The adhesive applicator, in a manner which will be described hereinafter in considerable detail, applies adhesive to the bag bottoms in a predetermined pattern defined by dots 31. After receiving adhesive, the bags (still with the flaps open) continue movement along with the outer surface 26 of the drum to a flap-folding station 32. Quite briefly, the flap-folding station includes flap-folding fingers 33 (only one of which is illustrated) which derive their motion from ring gear 22 through the medium of gears 34 and 35. The fingers 32 function to fold flaps 28 and 29 inwardly from the position of FIG. 14 to the position of FIG. 15 to complete formation of the bottom of the bag. Since the flap-folding apparatus forms no part of the present invention it has not been described in detail, and reference may be-made to US. Pat. No. 3,156,165 Weis issued Nov. 10, 1964, and also assigned to Crown Zellerbach Corporation, for a detailed description of the manner in which a suitable flap-folding apparatus may operate.

From the flapfolding station the bags are deposited from the drum 20 onto a suitable conveyor 36 for carrying the bags, to an assembly and packaging station (not shown).

Reference should now be made to FIGS. 3, and 6 to gain further understanding of the drive train by which the rotational movement of the ring gear 22 is transmitted to a rotor 37 of the adhesive applicator mechanism, the rotor being mounted for rotation with respect to a stator 38. An intermediate drive shaft 39 in the drive train is appropriately journalled for rotation in bearing components 40 carried by a frame member 41 (which frame member is mounted on the floor). One end of the drive shaft 39 has a gear 42 appropriately secured thereto, and this gear is so positioned that it meshes with the ring gear 22. The other end of the shaft 39 also has a gear 43 suitably secured thereto for rotation with the shaft. An idler gear 44 is rotatably supported from the main supporting frame of the apparatus through the medium of a mounting block or bracket 45 .(which bracket also sup ports the adhesive applicator mechanism), and the gear 44 is journalled for rotation about an axis defined by a bolt 46 passing axially through the gear and secured to the bracket 45 by a nut 47. The idler gear 44 is positioned so that it meshes with intermediate drive gear 43, and the idler gear 44 also meshes with adhesive applicator drive gear 48, the gear 48 being connected to the rotor element 37 of the applicator mechanism through the medium of a connector cylinder 49.

Now referring to FIGS. 2. and 6, the preferred construction and the assembled condition relationship of the rotor 37 and stator 38 may be clearly visualized.

The stator 38, in preferred form, comprises a shaft '50 which is generally circular in cross-section and has an axial adhesive-conducting passageway 51 extending from one end 52 thereof to a point about midway of the shaft. The passageway 51 is internally threaded at the end 52 of the shaft so as to receive an externally threaded end of an adhesive supply line 53 which is attached to the shaft in communication with the passageway 51. An integral enlarged annular external collar 54 is formed on the shaft approximately midway between the ends of the shaft in the region where the passageway 51 terminates. The

. collar 54 has a radial internal bore 55 formed by diametrically drilling through the collar from a point on the exterior surface 56 thereof to an inner point spaced slightly inwardly from a point on the exterior surface 180 removed from the point where the drill enters the surface. The end of the bore where the drill entered is thereafter plugged with a suitable plug 57. A hole 58 is formed by drilling between opposite side walls 59 and 60 of the collar in a manner so that the hole 58 intersects the bore 55. The hole 58 thereby provides outlet openings 59a and 60a on opposite sides of the collar, each of which openings is in fluid flow communication with the passageway 51 through the medium of bore 55. An internally threaded axially extending aperture 61 at the end 62 of the shaft 50 opposite the adhesive supply end permits reception of a bolt 63 for securing an end cap 64 thereon. The shaft also includes necked-down portions located on opposite sides of the collar which provide respective abutment surfaces 65 and 66 for a bearing 75 and a spacer 152. The shaft 50 may be formed of stainless steel or any other suitable material.

The rotor 37, in preferred form, comprises two complementary sections 67 and 68. As seen most clearly at FIGS. 2 and 6, the section 67 includes a circular central opening defined by an arcuate surface 69 which opening is slightly larger than the diameter of the shaft 50 in the region adjacent the opening. For example, the shaft diameter (distance X at FIG. 6) may be 1 /2 inches, and the rotor opening diameter (distance Y at FIG. 6) may be 4 of an inch greater. Stepped surface portions 70 and 71 extending outwardly from surface 69 provide respectively a seat for seals 72 and 73 and an abutment surface 74 for hearing 75 which is held in place by a retaining ring 76 and rotatably supports the rotor 37 from the stator shaft 50. The seals may be formed of flexible neoprene and are generally V-shaped in cross-sectional configuration whereby one leg of each seal is secured to surface 70 for rotation therewith, and the other leg of each seal bears resiliently against the shaft 50. A suitable lubricant for the seals may be inserted through an opening 77 which is closed by a removable plug. An inner rotor surface 78 extends perpendicularly or radially outward from surface 69, and the surface 78 together with axially extending surface 79 form a partial housing for the collar 54 on the stator. As will again be described later, in assembled condition of the applicator mechanism the surfaces 78 and 79 are spaced from adjacent collar surfaces 59 and 56, respectively, on the stator.

As seen most clearly at FIG. 8, the inner surface 78 of the rotor element 67 has a plurality of entrances 80 through formed therein. Each ofthe entrances 80 is connected by an individual internal duct 86 to an individualexit on the external surface 87 of the rotor. The exit portions of the duct connected to the entrances 80 form one leg 88 of a generally U-shaped (FIG. 9) adhesive applicator pattern. Each duct is internally threaded at the exit so as to be capable of receiving nozzles 89 therein which nozzles thereby provide individual exterior discharge surfaces. The ducts for each of the entrances 80 first extend equal axial distances perpendicularly away from the entrance surface 78 to a point below the leg 88 of the adhesive discharge pattern. Then the ducts extend radially upward to the discharge surface of the rotor. In

other words, the entrances 80 are each in substantially the same radial plane as their respective discharge nozzles,

.considering the radial planes as being planes originating along a line corresponding to the axis of rotation of the rotor 37 and extending radially outward to the outer surface 87 of the rotor.

As stated, the entrances designated as a group by the numeral 80 are used to supply, in sequence, adhesive to the nozzles 89 forming the leg 88 of the generally U-shaped pattern. The entrances 81 and 82 are used to supply adhesive to the first outer two nozzles 90 and 91 at the base 92 of the pattern. As seen at FIGURE 10, the ducts for the two entrances 81 and 82 are in substantially the same radial plane as the nozzles at the base of the U-shaped pattern, and these two entrances, when aligned with the adhesive outlet 59a on the stator collar 54, are supplied simultaneouly with adhesive, the duct path from each of these entrances first extending axially inwardly, thence radially upward to a respective nozzle.

A somewhat different duct pattern is used, however, to supply the remaining three nozzles 93, 94 and 95 at the base of the U-shaped pattern in rotor section 67. Entrance openings which are used to supply the latter three nozzles are designated by numerals 83, 84 and 85 (FIG. 8), and it is seen that these latter entrances are displaced from the radial plane of their respective nozzle discharge surfaces. Referring to FIGS. 8, l0 and 11, it is seen that the entrance 83 leads to a duct 96 (FIG. 11) which extends axially inwardly a short distance. Then the duct extends upwardly through a portion 96a formed by drilling a radial hole from the outer surface of the rotor, and the hole is thereafter closed with a plug 97. From the portion 96a, the duct extends in a return path 96b to rotor surface 98. The duct follows an arcuate peripheral groove 96c along the surface 98, which groove terminates at the same radial plane as the discharge nozzle 93. Then the duct extends axially inwardly again from a second entrance 96d (FIG. to a point immediately beneath nozzle 93; thence radially upwardly to the nozzle. Therefore, as disclosed clearly in the drawing (FIGS. 8, l0 and 11), there is a return path starting from entrance 83 on surface 78 which leads to surface 98, and the return path can be said to be generally U-shaped. This path includes a duct 96 (FIG. 11) extending inwardly from entrance 83 which can be considered to be one leg of the return path, a duct 96a which is the base of the U-shaped return path, and duct 96b which is the other leg of the return path.

The duct 99 from entrance 84 (FIG. 8) also follows a return path between surfaces 78 and 98; thence along groove 99c in surface 98 to a second entrance 99d in surface 98, and from the second entrance to a point below the nozzle 94; thence upwardly to the nozzle. Similarly, the duct 100 from entrance 85 leads between surfaces 78 and 98, through groove 1000; thence through a second entrance 100d to the nozzle 95. It is to be observed that the second entrances 96d, 99d and 100d are all located on surface 98 and are in substantially the same radial plane as the nozzles forming the base of the U-shaped pattern. As is clear at FIGS. 8 and 9, the ducts 99 and 100 also have portions formed by drilling behind the base of the U-shaped pattern and thereafter plugging the entrance to these drilled holes, as at 104 and 105.

The reason for the somewhat tortuous path with respect to the ducts from entrances 83, 84 and 85 is that it is desirable to supply no more than two entrances at a time from the stator opening. As long as all of the nozzles at the base of the U-shaped pattern are in the same radial plane it is necessary that the ducts supplying some of these nozzles have their entrances behind the plane, but it is necessary for the duct path to return to the plane at the base of the pattern. Then, considering the difliculty of the drilling at an angle in the rotor metal from any given surface, it will be appreciated that the duct arrangement for the entrances may be accomplished in the manner indicated by straight drilling in connection with arcuate grooving along the surface 98.

As indicated above, rotor section 68 is complementary to rotor section 67 just described. The rotor Section 68 also includes a circular opening 101 which is essentially the same diameter (distance Y at FIG. 6) as the central opening 69 in the section 67. Inner surface 102 extends radially outward from the surface defining the opening 101, and the surface 102 together with axially extending surface 103 also forms a partial housing for the collar 54 on the stator.

As is clear at FIG. 6, when the two complementary rotor sections 67 and 68 are secured together, the surfaces 78, 79, 102 and 103 together define an annular groove for receiving the shaft collar 54. The parts are so dimensioned, however, that the surfaces 78 and 102 are, in assembled condition, spaced apart from each other a distance of preferably between about .006 and .010 inch greater than the distance between surfaces 59 and 60 of the collar. This permits the surface 59 to be spaced from surface 78 a distance of about .003 to .005 inch, and similarly, permits the surface 60 to be spaced from surface 102 a distance of about .003 to .005 inch. In considering the proper spacing for clearance between the surfaces just mentioned, the minimum value is chosen so that there is assurance that there will be at least some clearance between the surfaces during relative rotation thereof. The maximum value is chosen so as to effectively confine the adhesive between the surfaces in a manner such that by the' time any of the adhesive might reach seals 72, 73 or 117, 118, the pressure exerted against the seals by the glue will be minimal. The adhesive or glue flow path is therefore confined in such a manner as to pass principally from outlets 59a and 60a on the stator collar in sequence to the entrances on the opposed inner surfaces of the rotor. There is also clearance between the surfaces 79 and 103 of the rotor and the outer surface 56 of the collar which may be on the order of 0.2 inch.

Rotor section 68 further includes a plurality of entrances which are essentially mirror images of the en trances 85 located on rotor section 67. It is to be understood that the entrances in surface 102, through appropriate ducts, supply nozzles located on the exterior surface of the rotor section 68 in a pattern forming the opposite leg 107 and remaining portion of the base 92 (FIG. 9) of the U-shaped adhesive pattern in the same manner as the entrances on surface 78 supply nozzles forming leg 88 and base portion 92 of the adhesive pattern on the rotor section 67.

While any suitable material may be used for the rotor sections, it has been found that brass or bronze is a desirable material for ease of machining and furnishing required strength and corrosion-resistant properties.

It should be noted here that a flattened annular shim 108 is clamped between surfaces 98 and 106 on rotor sections 67 and 68 so as to isolate the arcuate grooves 96c, 99c and s in section 67 from the grooves 109, 110 and 111 (FIG. 2) in rotor section 68.

The generally cylindrical connector member 49 for connecting the rotor 37 to the drive gear 48 is fixedly attached to the rotor sections 67 and 68 for rotation therewith by a plurality of threaded bolts 112 which pass through aligned holes 113 in both rotor sections (and through holes in the shim 108), the ends of the bolts being threaded into internally threaded holes 114 formed in an annular enlarged flange 115 at one end of cylindrical connector member 49. The bolts 112 then, in addition to joining the member 49 to the rotor 37, also function to firmly hold the rotor sections together. As seen clearly at FIG. 6, the internal diameter of the member 49 is greater than the external diameter of the portion of shaft'50 surrounded by the connector 49 so that the connector is free to rotate relative to the shaft.

An enlarged internal groove 116 on member 49 at the same end as flange 115 forms a seat for a pair of ringlike seals 117 and 118 each of which is generally V- shaped in cross-sectional configuration and includes one leg which abuts and is secured to the surface forming the groove 116, and another leg which, by virtue of the resiliency of the seals, is forced into engagement with the external surface of the stator shaft 50. The seals 117 and 118 may be made of the same materials as the seals 72 and 73.

The internal surface of the connector member 49v at the end opposite from the rotor 37 is enlarged as at 119 so as to permit reception of a bearing 120 therein. The outer race of the bearing 120 is in firm abutment with the inner surface 119 for rotation therewith and the inner race of the beaing is in firm abutment with the stator shaft 50. The end of connector 49 is firmly secured to drive gear 48 for rotation therewith by a plurality of spaced threaded bolts 121 extending through the gear 48 and threaded into internally threaded holes 122 in the end of the member 49. An annular ring 159 abuts the inner surface of the member 49 in the space between the outer race of the bearing 120 and the gear 48.

The end cap member 64 for supporting the end 62 of shaft 50 from supporting or mounting block 45 has an internal recess 123 at one end thereof which fits around the end of the shaft 50, and the cap member 64 is spaced from the inner race of bearing 120 by a sleeve 160 which also surrounds the shaft 50. The bolt 63 extends through the cap and is threaded into the aperture 61 at the end of the shaft 50. As will be pointed out hereafter in greater detail, the bolt 63, in addition to attaching the end cap to the shaft, also functions to provide initial relative axial adjusting motion between the rotor 37 and the stator 38.

Mounting block 45 (see FIG. 2) includes a body portion having an opening 124 extending completely therethrough of sutficient diameter to receive the end cap 64 therein. Opposite side walls of the block each includes a groove 125 and 126 (see also FIG. 7), which grooves are slidably mounted respectively on vertical main supporting frame members 127 and 128 so that the block may be moved vertically but not horizontally with respect to the frame members 127 and 128 once the block 45 has been properly positioned. An upwardly extending integral flange 129 on the block has an aperture 130 extending therethrough so that bolt 46 extending axially through idler gear 44 may be used to fixedly secure the idler gear to the flange 129 by fastening nut 47 on the end of the bolt once the bolt has been inserted through the idler gear and through the flange. An internally-threaded aperture 131 in the top wall of the mounting block is for receiving the threaded end of a stud 132 for mounting the block 45 from a main horizontal supporting frame member 133. As seen at FIG. 6, a coil spring 134 biases the block 45 away from the frame member 133, and the stud is inserted through an opening in the frame 133 and centrally through the spring. Threaded end 135 of the stud is fixedly attached to the block 45 by turning the stud into the threaded aperture 131. The opposite end of the stud is also threaded so that a nut 136 and lock nut 137 can be turned thereon, the nut 136-engaging the upper surface of frame member 133. Vertical adjustment of the entire assembly including gear 44, rotor 37 and stator 38 can be accomplished by appropriate adjustment of nuts 136 and 137.

Another mounting block 138 on the opposite side of the mechanism is used to support the opposite end of the shaft from the main supporting frame. This block also includes a central opening 139 extending through the block which receives the stator shaft from one end, and an adhesive supply line from the other end. Opposite side walls of block 138 are also provided with grooves 140 and .141 for slidably mounting the block on vertical frame members '142 and 143. An internally-threaded aperture 144 in the top surface of block 138 is for receiving a threaded stud 145 which, in assembled condition,

is surrounded by a coil spring 146. The stud, after nut 147 and lock nut 148 have been turned thereon, is used to support the block 138 from a horizontal main frame member 149 in a manner similar to the manner in which the stud 132 supports the opposite end of the stator shaft. Additionally, a threaded hole 150 in the side wall of the block is in communication with the central opening 139, and the hole 150 is for reception of a set screw 151 which firmly holds the end of the shaft in the opening 139 once the shaft has been properly positioned therein.

In the assembled condition of the parts as seen in FIG- URE 6, assuming the bolts 63, 112 and 121 have been tightened, it should be clear that the exact axial position of the rotor 37 with respect to the stator 38 is determined by the distance between surfaces 152a and 15211 of annular metallic spacer ring 152. The reason for this is that the ring 152 is clamped between the two opposed surfaces, one of the opposed being the abutment 66 on the stator and the other of the surfaces being the bearing 120 (which bearing, in assembled condition, is axially fixed with respect to the rotor). Thus, during initial assembly, if the surface 59 on the stator collar 54 is closer to surface 78 on the rotor section 67 than the surface 60 on the collar is to the surface 102 on the rotor section 68, it is only necessary to disassemble the parts and reduce the size of the spacer 152 (whic h night be accomplished by grinding it down) to positively assure that the distance between surfaces '59 and 78 is the same as the distance between surfaces 60 and .102. It is desirable that the opposite side surfaces of the collar be spaced equal distances from the entrance openings on opposite sides of the rotor to gain assurance that substantially equal charges of adhesive are supplied to opposite legs of the adhesive discharge pattern.

A representative nozzle 89, as illustrated at FIG. 13,

includes an externally-threaded shank portion 153 which enables the nozzle to be threaded into the end of each duct along the exterior surface of the rotor 37. A bore 154 extends axially through the nozzle which bore includes a necked-down portion 155 near the head of the nozzle. From the necked-down portion, the bore flares outwardly providing a generally conical surface 156 at the head which enhances the formation of a drop or globule of adhesive on the surface 156 as an adhesive charge is forced to the nozzle.

Once the parts have been properly assembled as described above, the adhesive applicator may be operated. As seen at FIG. 1, rotation of ring gear 22 in the direction indicated also imparts rotative motion to the rotor 37 of the adhesive applicator through the gear train indicated above. The drum 20 is also rotating in the direction indicated, and a slight space or nip is defined between the drum 20 and the external surface of the rotor. Adhesive is forced by pump 157 from reservoir 158 through supply line 53 to the end of the central passageway 51 through the stator shaft 50 at a positive pressure of about 15 to 18 p.s.i.g. The adhesive continues through passageway 51 and thence through bore 55 in collar 54 so that adhesive under pressure is available at outlet openings 59a and 6011 on opposite surfaces of the stator. The rotor is, of course, rotating relative to the stator, and the entrances 80-85 on rotor section 67 as well as the corresponding entrances on rotor section '68 sequentially and intermittently become aligned in fluid flow communication with the stator outlets. Such intermittent alignment of an entrance with the oulet causes an adhesive charge to enter the rotor entrances in sequence and the adhesive is forced through the ducts to the exterior discharge surface formed on each nozzle. A globule of adhesive is thus formed on each nozzle prior to the time the nozzle enters the nip between the rotor 37 and the drum 20. Bags with bottom flaps open are fed to the nip between the rotor and the drum in timed relationship so that the bottom flaps enter the nip just as the nozzles enter the nip. The adhesive globule by virtue of contact with the bag is 9 thereby deposited on the bag in the pattern indicated at FIG. 14. Then, during the next revolution of the rotor, additional globules of adhesive are supplied to the nozzles in a similar manner and, concurrently, another bag is being fed to the nip.

Automatic valving is thereby provided in that each entrance receives a charge of adhesive only during the time that the entrance is in alignment with a stator outlet. The pump is appropriately equipped with an internal relief valve to prevent an excessive pressure increase during periods when adhesive is not being supplied to the entrances.

The particular type of adhesive is not critical except that it should be of such a consistency or viscosity that it will form a bead or globule on the end of the nozzle, which head will remain on the end of the nozzle until the adhesive bead is brought into contact with the bag being advanced through the nip between the rotor and the drum. An adhesive which has successfully been used is a starch-base adhesive having a solids content of about 17% and a consistency about that of whipped cream.

It is to be especially noted that, except for the seals 72, 73, 117 and 118, the surfaces of the rotor are spaced from the stator surfaces and high speed rotation is thereby permitted without any excessive build-up of frictional heat. While there is some accumulation of adhesive in the space between the rotor and stator surfaces, the adhesive in these spaces will be under very little pressure because the main thrust of pressure of the adhesive charge is actually in a direct line of flow between the stator outlet and the rotor entrances as the entrances sequentially become aligned with the stator outlet. Any adhesive pressure which might exist on the seals is effectively prevented from reaching the exterior by the seals.

What is claimed is:

1. An applicator mechanism for use in apparatus for depositing a fluid material onto a receiving surface, said applicator mechanism including:

(a) a stator element comprising a circular shaft and having a passageway extending between an inlet opening connectable with a pressurized source of fluid material and an outlet opening located on a surface of the stator element, said shaft having an enlarged exterior collar providing the surface having the outlet opening, said collar having a radial bore connecting the passageway to the outlet opening;

(b) a rotor element rotatably mounted with respect to said stator and including an inner surface spaced from and extending substantially parallel to the stator surface including the outlet, the inner surface of the rotor element having at least one entrance leading through a duct in the rotor to an exterior discharge surface thereon, said entrance in one position of rotation being aligned in fluid flow communication with the outlet opening in the stator, and said entrance in another position being out of fluid flo'w communication with the outlet opening in the stator;

(c) seal means mounted between said rotor and stator for preventing fluid material from reaching exterior surfaces of the applicator except to the discharge surface; and,

(d) structure supporting the rotor and stator for such relative movement.

2. The mechanism as set forth in claim 1 wherein said inner surface of said rotor element has a plurality of entrances positioned for intermittent sequential alignment with the outlet opening on the stator, and each of said entrances leads through an individual duct to a respective discharge surface, said discharge surfaces together defining a predetermined pattern for discharge of the fluid material in accordance with the pattern.

3. The mechanism as set forth in claim 2 wherein the pattern includes a first leg portion extending in the direction of rotation of the rotor and a second base portion extending transverse to the direction of rotation of the rotor, and wherein entrances to respective discharge surfaces forming the first portion are in substantially the same radial plane as their respective discharge surfaces, and entrances to respective discharge surfaces in the second portion are displaced from the radial plane of their respective discharge surfaces, the said radial planes being planes originating along a line extending along the axis of rotation of said rotor and extending radially outward to the outer surface of the rotor.

4. The mechanism as set forth in claim 3 wherein the ducts connecting the entrances to the discharge surfaces forming the second portions each includes an internal generally U-shaped return path leading from the entrance to a second entrance formed on a second inner surface of the rotor, said second entrances being substantially in the same radial plane as the discharge surfaces of said second portions.

5. The mechanism as set forth in claim 2 wherein said discharge surfaces comprise removable nozzles positioned individually at the opposite end of said ducts from the entrance.

6. The mechanism as set forth in claim 1 wherein the surface including the outlet in the stator is spaced from the inner surface including the entrance on the rotor a distance between about .003 and .005 inch.

7. An applicator mechanism for use in apparatus for depositing a fluid material onto a receiving surface, said applicator mechanism including:

(a) a stator including a shaft circular in cross-section having a central axial passageway with an inlet opening connectable to a pressurized source of fluid material, said shaft including an enlarged annular collar having a central radial bore communicating with said passageway, and said collar having outlet openings on opposite sides thereof communicating with the bore;

(b) a rotor having a central opening surrounding said shaft and rotatably mounted with respect to said shaft, means including first and second opposed inner surfaces defining an annular groove within the central opening for receiving said shaft collar in spaced relationship thereto, said inner surfaces each having at least one entrance leading each through individual ducts to individual exterior discharge surfaces on the rotor, said entrances in one position of rotation being aligned in fluid flow communication with respective outlet openings in the stator, and said entrances in another position being out of fluid flow communication .with respective outlet openings in the stator;

(c) seal means mounted between said rotor and stator for preventing fluid material from reaching exterior surfaces of the applicator mechanism except to the discharge surface; and,

(d) structure supporting said shaft from a frame.

8. The applicator as set forth in claim 7 wherein said inner surfaces of said rotor elements each has a plurality of entrances positioned for intermittent sequential alignment with the outlet opening on the stator, and each of the entrances leads through an individual duct to a respective discharge surface, said discharge surfaces together defining a predetermined pattern for discharge of the fluid material in accordance with the pattern.

9. The applicator mechanism as set forth in claim 7 wherein said rotor includes first and second separable elements, said first element including said first inner surface, and said second element including said second inner surface.

10. The applicator mechanism as set forth in claim 7 wherein said seal means comprises resilient seals which contact said shaft at locations spaced from opposite sides of said collar.

11. The applicator mechanism as set forth in claim 7 which further includes a spacer clamped between opposed abutment surfaces by relative adjusting axial movement of said rotor with respect to said stator, one of said opposed surfaces being on said stator, and the other of said opposed surfaces being axially fixed with respect to said rotor, and means for providing the relative axial adjustment whereby the relative axial position of the rotor with respect to the stator can be adjusted by adjusting the size of the spacer.

12. The applicator mechanism as set forth in claim 7 wherein the first and second surfaces defining said annular groove on said rotor are spaced respectively from opposite sides of the collar of the stator distances between about .003 and .005 inch.

13. An applicator mechanism for use in apparatus for depositing a fluid material onto a receiving surface, said applicator mechanism including:

(a) a stator including a shaft having an internal passageway with an inlet opening connectable to a pressurized source of fluid material, said shaft including a collar with opposite side surfaces, said side surfaces being spaced apart a first, predetermined distance from each other, and said surfaces having outlet openings thereon in fluid flow communication with said passageway;

(b) a rotor including internal side surfaces defining a groove for receiving said shaft collar, said side surfaces which form said groove being spaced apart from each other a second, predetermined distance which is greater than said first predetermined distance, said internal side surfaces in said rotor each having at least one entrance leading each through individual ducts to exterior discharge surfaces on the rotor, said entrances in one position of rotation being aligned with respective outlet openings in the stator, and said entrances in another position being out of alignment with respective outlet openings in the stator; and

(c) seal means for preventing fluid material from reaching exterior surfaces of the applicator mechanism except to the discharge surfaces.

References Cited UNITED STATES PATENTS 3,091,216 5/1963 Scotti 118-411 X 3,135,628 6/1964 Johnson et a1. 3,152,011 10/1964 Gerard 118-211 3,255,729 6/1966 Weis 118212 WALTER A. SCHEEL, Primary Examiner

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