US3717184A

US3717184A - Sealing compound applying machine and method

Info

Publication number: US3717184A
Application number: US00073551A
Authority: US
Inventors: J Shepherd; K Bischof; R Hoskins
Original assignee: MIDCAL ALUMINUM Inc
Current assignee: MIDCAL ALUMINUM Inc
Priority date: 1970-09-18
Filing date: 1970-09-18
Publication date: 1973-02-20
Anticipated expiration: 1990-02-20

Abstract

Machine for lining container closures including: a rotable worm gear having a thread with a root shape adaptable to engage a substantial portion of the periphery of the closure, a portion of said thread having a lead angle of zero degrees; a passageway adjacent said worm gear for guiding the closures into engagement with the worm gear thread and maintaining such engagement; a lining dispensing nozzle positioned above said passageway coplanar with the zero degree lead angle portion of the thread; and timing means controlled by the radial position of the worm gear and associated with the nozzle to cause the lining material to be dispensed into the closure while it is engaged by the zero degree lead angle portion of the thread.

Description

United States Patent 1 Bischof et al.

[ 1 Feb.20,1973

[ SEALING COMPOUND APPLYING MACHINE AND METHOD [75] Inventors: Kaspar Bischot; Robert D. Hosklns; John M. Shepherd, all of Modesto,

[21] Appl. No.: 73,551

[52] US. Cl. ..141/1, 141/78, 141/167, 141/168,141/172,141/180,141/l83,

[51] Int. Cl ..B65b 1/04, B65b 3/04 [58] Field of Search .18/26 RR, DIG. 6; 117/97, 101; 118/55, 318,416; 141/1, 11, 12, 69,78,129, 167, 168, 172, 180, 183; 198/213; 264/311 [56] References Cited FOREIGN PATENTS OR APPLICATIONS 606,573 7/1960 Italy ..198/213 Primary ExaminerHouston S. Bell, Jr. AttorneyBoyken, Mohler, Foster and Schwab [57] ABSTRACT Machine for lining container closures including: a rotable worm gear having a thread with a root shape adaptable to engage a substantial portion of the periphery of the closure, a portion of said thread having a lead angle of zero degrees; a passageway adjacent said worm gear for guiding the closures into engagement with the worm gear thread and maintaining such engagement; :1 lining dispensing nozzle positioned above said passageway coplanar with the zero degree lead angle portion of the thread; and timing means controlled by the radial position of the worm gear and associated with the-nozzle to cause the lining material to be dispensed into the closure while it is engaged by the zero degree lead angle portion of the thread.

11 Claims, 13 Drawing Figures PATENTEDFEBZOIBH SHEET 1 BF 6 INVENTORS KASPAR BISCHOF ROBERT D. HUSH/N5 JOHN M. SHEPHERD 0444/ 5 61% 571 ATTOKNE PAIENTEUFEBZOISYS 3,717,184

SHEET 30F e INVENTORS RASPAR BISCHOF BY ROBERT D. HUS/(INS JOHN M. SHEPHERD PATENTED FEBZUIQTS snwunfs SEALING COMPOUND APPLYING MACHINE AND METHOD BACKGROUND OF INVENTION 1 Field of Invention This invention relates to a machine and method for dispensing a flowable material into containers. More specifically it concerns a machine and method for depositing either annular or overall linings into container closures.

2. Description of Prior Art Most container closures consist of a bottom wall which fits over the container opening and a side wall or skirt which is integral with the bottom wall and fits down over a portion of the neck or body of the container. A gasket, commonly referred to as a lining is interposed between at least the lip of the container and the mating part of the closure to form a hermetic seal therebetween. This lining is normally formed by dispensing a charge of a liquid sealant from a nozzle into the closure and then rapidly rotating the closure so that the sealant spreads out across its interior surface.

The liquid sealant is usually a plastisol a composition comprising a liquid plasticizer and a resin which does not dissolve in the plasticizer at ambient temperatures, but does at elevated temperatures. Thus, after the sealant-containing closure has been rotated, it is heated to dissolve the resin in the plasticizer thereby causing the plastisol to harden. This liquid to solid transformation is usually called curing or fluxing. As alternatives simple solutions of resins in water or organic solvents which harden on drying are'sometimes used in place of plastisols.

Two types of linings are used in the closure art; overall and annular. Overall linings are commonly used in bottle caps and crowns; whereas annular linings are used in jar and can closures and valve closures for aerosol bombs. Overall linings are discs with thickened edges which cover the bottom of the closure and the shoulder forming the bottom wall-skirt juncture. Such linings are formed by discharging sealant from a nozzles or other dispensing device into a closure seated on a vacuum chuck rotating at speeds in the range of about 2,500 to 6,500 r.p.m. This rotation causes the charge to be flung outwardly and banked against the bottom wall-skirt juncture.

Annular linings are a ring or band of sealant which seals the joint between the lip of the container and the closure interior. Such linings are made by placing the sealant charge at the sealing periphery of the closure and rotating the closure so that a ring of sealant covering only the mating area between the closure and the lip is formed. Significantly lowe'r chuck speeds are required for forming annular linings than are necessary for forming overall linings.

Three types of machines have been described for lining container closures. These are: reciprocating plates, rotating indexes and rotating escapement pockets. In the reciprocating plate devices, a flat plate equipped with a fork blade strips the lowermost closure from a vertical stack of closures and pushes that closure onto a rotating chuck and under a sealant dispensing nozzle, removing the previously lined closure in the same stroke. The rotary index devices use an input chute which feeds closures between the projecting spokes of a spoked turret which intermittently but progressively sweep the closures to and away from a sealant dispensing station.

The rotating escapement pocket device involve pnuematically conveying closures through an enclosed channel having an inlet and an outlet and a rotating pocket intermediate said inlet and outlet. The pocket has an upstanding sidewall. with an opening which, as it rotates, permits access from the channel into and out of the picket. The picket is fitted with a coaxially rotating vacuum chuck and a sealant dispensing nozzle is positioned above the chuck. In operation a closure is pneumatically accelerated along the channel toward the pocket. As the pocket rotates, its side wall opening mates with the input portion of the channel, allowing the closure to enter the pocket and be engaged by the rotating chuck. As the picket rotates further, the opening mates with the output portion of the channel and the closure is pneumatically ejected from the pocket.

The reciprocating plate and rotary index machines are quite bulky and heavy. Normally they require a heavy base and supporting parts in order to withstand the stress of rapid acceleration and deceleration forces caused by the sliding motion of the blade and the rotation of the turret. The rotating escapement pocket device is difficult to service because it is enclosed. It is necessary to keep the pneumatic lines completely open at all times to insure that the device operates efficiently and closures do not jam in the side wall opening.

INVENTION DESCRIPTION The present invention contemplates a machine which by worm gear action efficiently and rapidly transports a container or closure to a flowable material dispensing station, causes the container to dwell at the dispensing station during the dispensing operation and then transports the container away from the dispensing station. This machine comprises a worm gear having a thread with a root shape adaptable to engage a substantial portion of the container periphery and a 0 lead angle portion; a closure passageway longitudinally adjacent said worm gear for guiding the containers into. engagement with the worm gear thread and maintaining said engagement along the entire length of the worm gear; a flowable material dispensing means including a nozzle positioned above said passageway in the same plane as the 0 lead angle portion of the thread; timing means controlled by the radial position of the 0 lead angle portion of the thread and operatively associated with said nozzle to actuate same to dispense said material into a container while it is engaged by the 0 lead angle portion; and power means to drive the machine.

When adapted to dispense lining sealant into container closures the above described machine includes means for rotating the closure while it is engaged by the 0 lead angle portion of the thread. Such means are usually a vacuum chuck positioned in an aperture in the floor of the passageway directly opposite the 0 lead angle portion. Means for unseating a closure from the chuck just prior to the disengagement of the closure from the 0 leading angle portion may also be included. This chuckclosure release means may be a mechanism for vertically reciprocating the chuck to move it up above the level of the floor to engage a closure riding in the 0 lead angle portion and down below the floor level causing the floor to strip the closure from the chuck prior to the closure s emergence from the lead angle portion. Alternatively and preferably, it involves having the portion of the passageway floor opposite the 0 lead angle position and radially surrounding the chuck capable of vertical reciprocation in time with the radial position of the 0 lead angle portion. In this alternative, the chuck remains vertically stationary while the floor portion moves down below the top of the chuck thereby permitting a closure to seat on the chuck and up to push the closure off the chuck.

Liquids or other flowable materials may be dispensed into containers using the above described machine by feeding containers into the input end of the passageway. As the worm gear rotates the portion of the worm gear thread rearward of the 0 lead angle portion picks up the containers and pushes them along the passageway toward the dispensing station. In order to keep the containers separated in the passageway and allow them ample dwell time at the dispensing station it is desirable to position the 0 lead angle portion of the thread a significant distance from the input end of the worm gear and have the lead angle of the thread portion rearward of the 0 lead angle portion continuously increase up to the 0 lead angle portion. Usually the initial lead angle of said rearward portion will be in the range of to and increase up to 40 to 50. When the container reaches the 0 lead angle portion its linear movement along the passageway stops and the liquid is dispensed into it. The worm gear must have a sufficient diameter and the 0 lead angle portion must occupy a sufficient segment of the worm gear circumference to enable the dispensing (and spinning in the case of closures) operation to be completed while the container is riding in the 0 lead angle portion. Normally the worm gear will be 1 to 10 inches in diameter and the 0 lead angle will occupy 10 to 300 of the circumference. As the worm gear continues to rotate the portion of the thread toward the 0 lead angle portion, being positive in lead angle, pushes the container away from the dispensing station and along the passageway to the output end thereof.

In contrast to the prior art the rotation of the worm gear of this invention does not cause significant stress requiring massive base support. Moreover, the container passageway may be left open to facilitate easy maintenance. Also, since the containers are transported by mechanical means rather than pneumatic means, there is no problem with air line plugging and significantly less change of closure jamming.

It is a primary object of this invention to provide a machine which quietly and efficiently dispenses flowable materials into containers by engaging the containers with a worm gear adapted to transport the containers to a dispensing station, hold the containers stationary while at the dispensing station and transport them away from the dispensing station. Another object is to provide a machine for makingeither overall or annular linings in container closures by engaging the containers with a worm gear which carrier them to a dispensing station, holds them linearly stationary while sealant is dispensed therein and a rotating vacuum chuck engage and rotates them and removes them from the dispensing station. Yet another object is to provide a unit for forming overall or annular linings in containers closures which may be multiplicated and arranged in tandem to form a compact multi-unit machine of high output and low floor space.

In the attached drawings:

FIG. 1 is a perspective view of the preferred embodiment of the container closure lining machine of this invention looking from the output end thereof;

FIG. 2 is a diagrammatic view of the path of the closure along the closure passageway past the sealant dispensing station and onto a fluxing oven;

FIG. 3 is a top plane view of the worm gear and adjacent closure passageway with a closure jet about to enter the 0 lead angle portion of the worm gear thread;

FIG. 4 is a top plan view similar to FIG. 3 with the worm gear rotated such that the closure is entering the 0 lead angle portion of the thread;

FIG. 5 is a top plan view similar to FIG. 3 with the worm gear rotated such that the closure is riding the 0 lead angle portion;

FIG. 6 is a top plan view similar to FIG. 3 with the worm gear rotated such that the closure is just emerging from the 0 lead angle portion;

FIG. 7 is a partial sectional view of the container closure lining machine taken along line 77 of FIG. 1;

FIG. 8 is a partial sectional view of the container closure lining machine taken along line 8-8 of FIG. 3 showing two container closure lining units in tandem;

FIG. 9 is an enlarged partial sectional view along line 9-9 of FIG. 8 showing the chuck-closure release mechanism of the machine of FIG. 1;

FIG. 10 is an enlarged partial sectional view along line 10 of FIG. 7 illustrating a closure in the passageway with the chuck-closure release mechanism in its release position;

FIG. 11 is an enlarged sectional view along line 10- 10 of FIG. 7 showing a closure in the closure passageway with the chuck-closure release mechanism in position permitting the closure access to the chuck;

FIG. 12 is a perspective view of the drive mechanism and circuitry of the machine of FIG. 1; and

FIG. 13 is a set of graphs illustrating the relationship between the linear velocity of the closure in the closure passageway, the vertical reciprocation of the chuckclosure release mechanism and the discharge of the sealant dispenser.

For convenience, the right-hand side of the apparatus as seen in FIG. 1 is called the forward or output side and the left-hand side thereof is called the rearward or input side. The input-output direction is called longitudinal.

As shown primarily in FIGS. 1 and 7, a frame, generally designated 1, is the basic support means of the apparatus. Frame 1 is an open-centered rectangular table which includes a pair of lateral top frame members 3, 4 and a pair of longitudinal top frame members, 15, 16 supported on a set of four legs 2.

Cross frame members

5, 6 extend longitudinally between legs 2 below

members

15, 16, respectively, and lateral

cross frame members

7, 8 extend laterally between legs 1 below top frame members 3, 4, respectively. All of these frame members may be made of hollow rectangular iron beams if desired.

The basic mechanism for moving closures 23 past the dispensing station is worm gear 10, which may be made out of any wear resistant material such as hard steel or plastic. Worm gear is a single thread, cylindrical worm having flat crests 11 and roots 12 which are deep and wide enough to accommodate in engaging relationship a substantial portion of the periphery of the closures 23. Inasmuch as the illustrated apparatus is tailored to apply sealing compound into bottle closures or caps, roots 12 are semicircular. The forward portion of the thread of worm gear 10 is helical an it lead angle increases from left to right up to a 0 lead angle portion 13 which extends over 200 of the circumference of the worm gear 10. Small metal wear plates 14 are positioned on the crest adjacent 0 lead angle portion 13 at the transition points between the forward and rearward helical thread portions of worm gear 10 and 0 lead angle portion 13. Shaft 18 extends axially out of each end of worm gear 10 and is journaled in bores 19 in square blocks 20, 21 mounted on the top sides of frame members 3, 4, respectively.

The linear path of closures 23 through the apparatus of FIG. 1 is defined by closure input chute 22, closure passageway 26 and closure output chute 33. Closure input chute 22 is a channel or trough open at the top and adapted to gravimetrically guide closures 23 into the entrance of passageway 26. A pair of parallel bars 24 disposed longitudinally in the trough opening and supported at spaced intervals by crossbars 25 keep the closures 23 from falling out of closure input chute 22. Input chute 22 feeds the closures, mouth upwardly, onto the input end of closure passageway 26.

Closure passageway 26 is positioned axially of worm gear 10 along its entire length. Closure passageway 26 includes a floor 27 and a side wall 31 which extends upwardly from the edge of floor 27 opposite that adjacent worm gear 10. Floor 27 lies approximately in the plane of the horizontal diameter of worm gear 10 and has a slot or gap 28 positioned directly opposite the 0 lead angle portion 13. Side wall 31 keeps the closures 23 in passageway 26 as they pass from the input to the output end thereof. As a closure 23 moves into the input end of passageway 26 it is engaged by the initial helical portion of the thread of worm gear 10 and is slid along toward'0" lead angle portion 13. The longitudinal force component exerted on the closure by the trailing edge of the thread causes the cylindrical closures 23 to slowly rotate as they are pushed by the thread along passageway 26. In the 0 lead angle portion 13 there is no such longitudinal force component; thus there is no linear displacement of the closures 23 while they are engaged thereby. It is at this position is passageway 26 that the sealant is dispensed into the closures. The output end of closure passageway 26 feeds into closure output chute 33.

Output chute 33 is a downwardly inclined trough adapted to receive closures 23 from passageway 26 and gravimetrically convey them to a fluxing oven (not shown). The bottom of input chute 22, floor 27and the bottom of output chute 33 should be made from a low friction material such as polished metal.

FIGS. 7, 10 and 11 best illustrate the conventional vacuum chuck 34 which is used to rapidly rotate the closures at the point at which the liquid is dispensed into them. Vacuum chuck 34 primarily comprises a vertically disposed hollow, elongated spindle 35 with a circular axial bore 36 extending its entire length. The top of bore 36 is threaded and the top ofspindle 35 has a radial flange 38 extending outwardly therefrom. A small extension tube has a bore 136 of smaller diameter than bore 36 which communicates with bore 36 when tube 135 is screwed into bore 36. Tube 135 extends upwardly from spindle 35 with its upper end protruding substantially centrally into slot 28 slightly below the top side of floor 27.

The lower end of spindle 35 is hermetically journaled in housing 37 which is mounted in aperture 42 of elongated, rectangular bar 40. Bar 40 is positioned inwardly of and below frame member 7 and extends laterally for a substantial portion of the distance between legs 2. Each end of bar 40 is rigidly connected to an end bar 41 which in turn is rigidly affixed to a leg 2. Spindle 35 is supported intermediate slot 28 and housing 40 by bearings in

sleeves

45, 46, which are mounted on the top side of plate 43 and the bottom side of plate 47, respectively. Plate 43 extends laterally between

frame members

5, 6 with its ends rigidly mounted on the top sides of

frame members

5, 6. Similarly, plate 47 extends laterally between

frame members

15, 16 and its ends are rigidly mounted on the bottom sides thereof. Aperture 44 in plate 43 and aperture 48 in plate 47 permit the passage of spindle 35 therethrough.

Housing 37 has an aperture in its bottom which communicates with bore 36 and is hermetically connected to trap 52 by tube 49. Trap 52 has a sump at its bottom which acts as a receptable for any liquid for foreign matter which drops into

bores

136, 36. The sump of trap 52 is fitted with a removable plug 51, in order that liquid and other matter may be periodically drained off. The forward side of trap 52 is fitted with an inlet 53, adapted to receive a vacuum conduit 54. Vacuum conduit 54 is ultimately connected to a vacuum source (not shown). Thus a vacuum may be continuously drawn through trap 52, tube 43, housing 37 and bores 36, 136 such that when a closure 23 is seated on top of tube 135 it is held firmly by the suction of the vacuum.

The chuck-closure release mechanism shown in FIGS. 10 and 11 is a vertically reciprocating, inverted L-shaped platform 55. The horizontal portion 56 of platform 55 radially surrounds the top of tube 135. Portion 56 has an aperture 61 for receiving tube 135, and its shape is such that it fits snugly into gap 28 with its inward edge closely adjacent the periphery of worm gear 10 and its outer edge extending below and slightly outwardly of wall 31. The vertical portion 57 of platform 55 extends downwardlyfrom the outward edge of portion 56 and is bolted to an L-shaped base at the inner vertical side thereof by bolts 59. The horizontal side of base 58 extends outwardly and is bolted by bolts 60 to an elongated, rectangular trough 62, which runs laterally for substantially the entire distance between

frame members

15, 16. As shown in FIGS. 9-11 62 has a flat bottom 63 with an aperture 65 through which spindle 35 passes, a pair of lateral side walls 64 and a pair of longitudinal end walls 68. Aperture 65 is surrounded by a boss 66 which extends upwardly from trough bottom 63. In addition to serving as a base for the platform 55, trough 62 is a receptable for any liquid which may squirt into aperture 61 or the portion of gap 28 not filled by horizontal portion 56 instead of into a closure 23. Any liquid falling down through such spaces will splash off radial flange 33 onto trough bottom 63. Boss 66 prevents such liquid from running down the sides of aperture 65 and shaft and fouling mountings on and the journal for spindle 35. The forward sidewall 64 is fitted with a spigot 67 to remove accumulated liquid from trough 62.

Trough 62 (and thus platform is cam-driven vertically by the action of disc cam 85, spring loaded radial follower 71 and cylindrical follower stem 70. Vertical guide plates 84 providing horizontal support for trough 62 are mounted at each rearward end of plate 47 and extend upwardly therefrom such that the upper ends of their forward sides are in slidable contact with the outward side of rearward trough wall 64. The upper forward side of plate 84 is periodically lubricated to maintain said slidable contact.

The top of follower stem is rigidly connected to a flat plate 69 mounted on the underside of trough bottom 63. From flat plate 69 stem 70 extends downwardly through aperture 79 in plate 47 and aperture 76 and sleeve 75, which is bolted to the underside of plate 47. A helical compression spring 74 circumscribes stem 70 between the bottom of sleeve 75 and the top of flange 78 keeping radial follower 71 in contact with disc cam 85 at all times and preventing backlash. Stem 70 has an aperture near its bottom which extends diametrically therethrough. This aperture receives connecting arm 72, which is externally threaded at its forward end and has a radial flange 80 extending outwardly near its rearward end. A hexhead nut 73 removably affixes stem 70 to connecting arm 72 forwardly of flange 80. The rearward end of connecting arm 72 is suitably journaled axially in radial follower 71 so that radial follower 71 is free to follow the circumferential surface of disc cam 85.

Disc cam is centrically mounted on shaft 87. Shaft 87 extends longitudinally between

frame members

7, 8 and is journaled in sleeve 88 at its forward end and in sleeve 89 at its rearward end. The forward end of shaft 87 extends through frame member 7 and has a hand crank 90 attached thereto.

As illustrated in FIGS. 7, 8 and 12, there are, two independent drive systems involved in the apparatus of FIG. 1 One rotates chuck 34 and the other drives worm gear 10, disc cam 85 and sealant dispenser firing mechanism 105. Chuck 34 is belt driven by variable speed electric motor 91 mounted on plate 96. Electric motor 91 is of sufficient horsepower to rotate spindle 35 and tube 135 at speeds in the range of about 1 to 6500 rpm. Shaft 94 of motor 91 is positioned parallel to spindle 35 and has a driving sprocket 93 mounted near its bottom end. A driven sprocket 92 is mounted on spindle 35 directly opposite sprocket 93. An open timing belt operatively connects sprocket 93 to sprocket 92.

Motor 99, which has a rearwardly extending shaft and a driving sprocket 101 mounted on shaft 100,-

drives cam 85, worm gear 10 and firing mechanism 105. An inner driving sprocket 102 and an outer driven sprocket 103 positioned rearwardly of driving sprocket 102 are mounted on the rearward end of shaft 87, which extends through and rearwardly of frame member 8. An open timing belt 104 connects driving sprocket 101 of motor 99 to driven sprocket 103. Driving sprocket 102 is operably connected by timing belt 111 to firing mechanism sprocket 107 mounted inwardly of firing mechanism 105 on shaft 106 and to worm gear sprocket 110 mountednear the rearward end of shaft 18. Shaft 106 is suitably journaled in bearings in

plates

108, 109.

A conventional sealant dispenser or gun, generally designated 115, is adjustably mounted directly above chuck 34. Its adjustable mounting includes rod 116, block 117, and rod 120. Rod 116 is rigidly attached on the top side of frame member 4 and extends upwardly therefrom adjacent closure output chute 33. Its upper end extends through vertical bore 118 in block 117. Block 117 also has a horizontal bore 119 at its opposite end and a pair of set screw bores 121 which communicate with bores 118 and 119, respectively. Rod extends horizontally through bore 119 and rearwardly therefrom.

Rods

116 and 120 are respectively positioned in bores 118 and 119 by set screws 122, which permit vertical and horizontal adjustment of dispenser 115. Rod 120 has an axial threaded bore (not shown) in its rearward end. A flat plate 123 with an externally threaded neck 147 extending therefrom is removably attached to the rearward end of rod 120 by screwing neck 147 into the axial bore of rod 120. Head 124 of dispenser 1 15 is bolted to flat plate 123.

Head 124 is basically a chamber for holding sealant under about 60 to 2,000 psig at ambient temperature to about 130F. It has an inlet 125 for receiving inlet conduit 126 which is connected to the source of sealant and an outlet 127 which receives outlet conduit 128. Outlet conduit 128 leads back to the sealant supply. In this manner sealant may be continuously pumped into head 124 via conduit 126 and recirculated back to its 1 source via conduit 128. It should be understood that such recirculation is entirely optional in this apparatus.

Positioned centrally on the bottom of head 124 directly over the top of bore 136 is nozzle 129. Nozzle 129 is positioned sufficiently close to passageway 26 to be able to accurately squirt sealant into a closure seated on chuck 34 without splashing. For making annular linings nozzle 129 is positioned to dispense the sealant near the interior bottom wall-skirt juncture of a closure seated on chuck 34.

Within head 124 and intermediate the sealant holding chamber thereof 'and the inlet of nozzle 129 is a solenoid valve (not shown) which is actuated by the plunger of solenoid 130. Solenoid 130 in turn is actu ated by firing mechanism 105 which operates on the same principle as an automobile ignition timer. That is, firing mechanism 105 has a cam-actuated contact lever which periodically opens and closes the circuit (FIG. 12) of which solenoid 130 is an element. Since the cam of firing mechanism 105 is driven by shaft 106, the opening and closing of said circuit may be timed with the rotations of worm gear 10 (and thus the radial position of 0 lead angle portion 13) and disc cam 85 As illustrated in FIG. 12 a vacuum switch 131 is connected in said circuit in series with firing mechanism 105. Vacuum switch 131 is connected to the vacuum line of chuck 34 by flexible tubing 133 which is received into the stem of T-joint 132 while flexible tube 134 connects the opposite end to the vacuum source. Thus when a closure 23 is seated over bore 136 closing that end of the vacuum line of chuck 34 the suction caused thereby closes vacuum switch 131 and permits firing mechanism 105 to actuate solenoid 130 and open the solenoid valve within head 124. In contrast, when a closure 23 is not seated over bore 36 the vacuum line of chuck 34 is open causing vacuum switch 131 to be open and thus preventing firing mechanism 105 from actuating solenoid 130. In this manner unless a closure is positioned beneath nozzle 129 dispenser 115 will not fire.

The preferred embodiment of this invention is also equipped with a closure hold up mechanism, generally designated 140, which blocks the inlet of passageway 26 unless a sufficient number of closures are backed up in input chute 22. It includes a cylindrical housing 141 mounted on support 139 directly above the inlet of passageway 26, a pneumatic plunger 142 movably suspended within housing 141 with its bottom end protruding out the bottom of housing 141, a compressed air conduit one end of which is connected to a compressed air supply and the other to the top of housing 141, and a switch (not shown). The switch 144 is wired to contact points 145 which extend downwardly into input chute 22. In operation as long as contact points 145 are engaged by a closure 23, the switch remains open and plunger 142 remains retracted within housing 141. If contact points 145 are not engaged by a closure, the switch closes thereby opening compressed air conduit 143. The compressed air thus flows into the top of housing 141 and drives plunger 142 downwardly into the inlet of passageway 26 to prevent the closures from being engaged by the thread of worm gear 10.

The basic function of the above described apparatus is diagrammatically illustrated in FIG. 2. The apparatus operates to move and guide closures or other containers in a predetermined path at a predetermined rate up to the point at which a liquid is dispensed into their open mouths. The linear displacement of the closure is temporarily stopped at that point. While the linear velocity of the closure is zero, a predetermined amount of liquid is squirted into it and it is rotated for a predetermined length of time. This rotation places a centrifugal force on the liquid causing it to spread outwardly to the side wall of the closure. The rotation is then ceased and the linear displacement of the closure is restarted; thus removing it from the liquid dispensing station.

The timing of this sequence of events is graphically illustrated in FIG. 13, in which the top line represents the linear velocity of the closure 23; the second line the vertical motion of the platform 55 with the downward direction as positive; and the lower line the amount of liquid dispensed by the dispenser 115. The ordinate units of FIG. 13 are degrees of rotation of worm gear 10, with representing the point at which a closure is initially engaged by the thread of the worm gear. As illustrated, the closure accelerates for approximately the first l,080 of rotation since the lead angle of the thread up to that point is constantly increasing. At the 0 lead angle portion 13 the velocity of the closure is reduced to zero and remains zero for 200 of rotation (0 lead angle portion 13 occupies 200 of the circumference of the worm gear As the closure thus comes to a stop in closure passageway 26, the piatform 55 moves downward, permitting the rotating chuck 34 to engage the closure and spin it. Almost immediately thereafter dispenser 1 15 squirts the liquid into the open mouth of the closure. As indicated by the flat peak in the second tracing, platform 55 remains in a downward position for a substantial portion of the 200 of rotation during which the linear displacement of the closure is zero. Near the end of this 200 of rotation platform 55 moves upward; thus disengaging the closure from the rotating chuck and terminating its spin. It will be appreciated that the second tracing of FIG. 13 is equivalent to the rise-dwell-return diagram for disc cam 85. After the 200 of rotation during which the lead angle of the thread is 0, the lead angle of the thread again becomes greater than 0 and exerts a horizontal force component on the closure side wall, thus moving the closure off platform 55 and along passageway 26 to the fluxing oven.

The way in which the apparatus of FIG. 1 performs the above-described functions may be further understood by referring to FIGS. 3 through 6 and 10 and 11. FIGS. 3 through 6 show a sequence of top views of a line of five closures in passageway 26 and engaged by worm gear 10. The sequence is taken over about 225 of rotation of worm gear 10.

In FIG. 3, the forwardmost closure has just left the 0 lead angle portion 13 of the thread and is being moved off platform 55 and along passageway 26 toward output chute 33. The closure next in line is approaching the 0 lead angle portion 13 and has already begun to move onto platform 55 which is in its up position. The rearwardmost closure is just being engaged by the thread of worm gear 10; whereas the remaining two closures have already been picked up by the thread and are moving along passageway 26 toward platform 55. Since the lead angle over the first l,080 of rotation of worm gear 10 is constantly increasing, the closures are accelerated as they move along passageway 26 toward platform 55. This acceleration keeps the closures well spaced in passageway 26 and permits a closure engaged by the 0 lead angle portion 13 to swell therein while seated on top of bore 136 without the following closure running into it from behind.

FIG. 10 is a sectional view, looking rearwardly along passageway '26, which illustrates the position of platform 55 as it is in FIG. 3. In FIG. 10 platform 55 is up, with horizontal portion 56 slightly higher than the upper end of tube 135 and almost flush with floor 27 of passageway 26. While platform 55 is in this position, tube 135 cannot engage and spin closure 23. Platform 55 is in this position due to the fact that follower 71 is riding on lobe 86 of disc cam 85. The timing between the rotation of worm gear 10 and disc cam is such that platform 55 is in the up position as long as the 0 lead angle portion 13 is not directly opposite floor 27.

In FIG. 4, the forwardmost closure has moved completely off platform 55 and is nearing the brink of closure output chute 33. At the same time the next closure in line is just entering the 0 lead angle portion 13 and has wholly moved onto the platform 55, which has begun to drop to permit the rotating chuck 34 to engage the closure bottom and rotate it. The remaining three closures are progressing along passageway 26 toward platform 55.

At a point intermediate the positions shown in FIGS. 4 and 5 dispenser has fired and squirted a droplet (shown in FIG. 5) of sealant into the closure seated on chuck 34.

FIG. 5 shows the forwardmost closure clear of the thread of worm gear 10 and the next closure in line in the lead angle portion 13. At this stage, platform 55 is down and chuck 34 is in engagement with that closure and is rapidly rotating it. FIG. 11 is a sectional view similar to FIG. 10, looking rearwardly along the passageway 26 but showing the position of platform 55 as it is in FIG. 5. In FIG. 11 platform 55 is in its down position, with horizontal portion 56 slightly below the top edge of tube 135. The closure is seated on top of tube 135 and is held in place thereon by the suction of the vacuum drawn through

bores

136, 36. At this point this closure is not moving linearly in passageway 26 and is in the 0 lead angle portion 13 of the thread. With platform 55 in its down position, follower 71 has moved off lobe 86 and is following the regular circumference of disc cam 85 as in FIG. 8. As indicated previously, droplet 155 has already been dropped into the closure by dispenser 115 and, as illustrated, has spread outwardly toward the closure side wall. The remaining three closures in the line have progressed forwardly along passageway 26 towards platform 55.

In FIG. 6 worm gear 10 has rotated such that the forwardmost closure is at the brink of closure output chute 33; while the closure next in line is just emerging from the end of the 0 lead angle portion 13. At this stage, platform 55 is moving up and disengaging the closure from chuck 34. Droplet 155 has complete spread out to the juncture of the closure bottom and side wall. As soon as the upcoming rearward inclined edge of the thread immediately forwardly of the end of the 0 lead angle portion 13 engages that closure, it will begin moving off platform 55 along passageway 26 toward output chute 33. As illustrated, the third closure in line is still in the initial helical thread portion of worm gear 10 and is approaching 0 lead angle portion 13; the beginning of which can be seen on the horizon of worm gear 10. The remaining two closures are moving forwardly along passageway 26 toward platform 55.

As illustrated in FIG. 8, two parallel lines for dispensing sealant or other liquid into closures or other containers may be run in tandem. Except for the drive mechanisms, trough 62 and dispenser firing mechanism 105, these lines are basically duplicates of each other. The drives, e.g.

electric motors

91, 99, firing mechanism 105 and trough 62 may be commonly used by both lines. Thus, driving sprocket 93 is positioned laterally between and rearwardly of driven

sprockets

92, 152 of

chucks

34, 151, respectively These three sprockets all lie in the same plane and are connected by timing belt 95,'which forms a triangle with a sprocket at each point. Similarly, driving sprocket 102 driven the driven sprockets of both of worm gears 10, 146 with timing belt 111. Likewise, firing mechanism 105, also being driven by sprocket 102 via belt 111, is connected to the dispenser associated with the worm gear 146 line so that it and dispenser 115 fire in unison. Trough 62 runs laterally under each line directly below the dispensing station and is the common support for the platforms surrounding the tops of

chucks

34, 151. Since trough 62 is activated by cam 85, the platforms of each line rise and fall in unison.

As will be apparent from the above, any number of lines may be arranged in parallel. Units of two lines each are convenient for running with a single set of drive mechanisms and a single dispenser firing mechanism.

Other modifications of the above-described machine will be readily apparent to those of ordinary skill in the art. For instance the worm gear may be double threaded and used to service adjacent lines simultaneously. Such other modifications are intended to be within the scope of the following claims.

WE CLAIM:

1. Method for lining container closures comprising a bottom wall and a skirt including the steps of:

a. mechanically pushing said closures along a predetermined restricted path at a constantly increasing linear velocity toward a lining compound dispensing station;

b. reducing said linear velocity to zero at said station;

0. dispensing a predetermined amount of lining compound onto the interior surface of said bottom wall while said linear velocity is zero;

d. rotating said closures after said lining compound is dispensed therein while said linear velocity is zero for a period of time sufficient to allow said lining compound to spread to the interior juncture of said bottom wall and skirt;

e. at the end of said period mechanically pushing said closure along said path away from said station.

2. A method according to claim 1 wherein:

f. the linear velocity of said closure is reduced to zero substantially instantaneously.

3. A method according to claim l wherein the rotation of said closures is effected by:

f. dropping said closures vertically downward into engagement with a rotating vacuum chuck;

g. maintaining said engagement for said period; and

h. at the end of said period pushing said closures vertically upward thereby stripping them off said chuck.

4. A machine for dispensing a flowable material into containers comprising:

a. container feeding means which continuously feeds a line of said containers onto b. one end of an elongated stationary container passageway where a substantial portion of the periphery of the containers is engaged by a first portion of the thread of c. a rotating worm gear positioned laterally adjacent the passageway such that said passageway maintains the engagement of the containers by said thread; said first portion of the thread having a constantly increasing lead angle which rapidly conveys the containers along the passageways at a constantly increasing velocity into engagement with d. a zero degree lead angle portion in the thread which temporarily stops the movement of the container along the passageway during which a predetermined amount of the fiowable material is dispensed into the container from e. a flowable material dispensing means the timing of which is controlled by the radial position of the zero degree lead angle portion, and the container is engaged and spun by f. a rotating vacuum chuck positioned in the passageway opposite the zero degree lead angle portion;

g. said zero degree lead angle portion being followed by a positive degree lead angle portion of the thread which extends from said zero degree lead angle portion to the other end of the passageway and which engages the container, rapidly conveys it along the passageway from the zero degree lead portion to strip the container off the chuck and downwardly to a position below the top of the chuck thereafter.

9. A machine accor e. a sealing compound dispenser, the timing of which angle portion and discharges it from said other end f. a rotating vacuum chuck positioned in the of the passageway; and passageway opposite the 0 lead angle portion power means to drive the machine. whereby the closure is spun;

A machine according to claim 4 including: g. said zero degree lead angle portion being followed disengaging means for disengaging the container by a positive degree lead angle portion of the from the vacuum chuck immediately prior to the thread which extends from said 0 lead angle pordisengagement of the container from the zero tion to the other end of the passageway and which degree lead angle portion. engages the closure, rapidly conveys it along the 6. A machine according to claim 5 wherein said dispassageway from the zero degree lead angle porengaging means includes: tion and discharges it from said other end of the j. a vertically reciprocating platform radially surl5 passageway; and

rounding said chuck the reciprocations of which h. power means to drive the machine.

are controlled by the radial position of the zero 8. Amachine according to claim 7 wherein:

degree lead angle portion whereby the platform i. said positive lead angle portion which follows the moves upwardly immediately prior to the disenzero degree lead angle portion has a constantly ingagement of the container from the 0 lead angle creasing lead angle whereby the closures are conveyed away from the zero degree lead angle portion at a constantly increasing ve locity.

ing to claim 7 including:

disengaging means for disengaging the closures from the vacuum chuck immediately prior to the disengagement of the closure from the 0 lead angle portion. 10. A machine according to claim 9 wherein said disengaging means includes:

j. a vertically reciprocating platform radially surperiphery of the closure skirt is engaged by a first portion of a thread of a rotating worm gear positioned laterally adjacent the passageway such that the passageway mainwhich temporarily stops the movement of the closure along the passageway during which sealing compound is dispensed onto the interior surface of the bottom wall of the closure from rounding said chuck the reciprocations of which are controlled by the radial position of the zero degree lead angle portion whereby the platform moves upwardly immediately prior to the disengagement of the closure from the zero degree lead tains the engagement of the closures by the thread, 35 said first portion of the thread having a constantly angle Porno to Smp closure 9 the chuck and increasing lead angle which rapidly conveys the downwardly to a Posmon below the top of the closures along the passageway at a constantly inchuck thefeaften creasing velocity into engagement with l1. machine according to claim 7 wherein:

d. a zero degree lead angle portion in the thread 40 531d worm gear has dlametel' of about 1 to 10 inches and the zero degree lead angle portion occupies about 10 to 300 of the circumference of said worm gear.

Claims

1. Method for lining container closures comprising a bottom wall and a skirt including the steps of: a. mechanically pushing said closures along a predetermined restricted path at a constantly increasing linear velocity toward a lining compound dispensing station; b. reducing said linear velocity to zero at said station; c. dispensing a predetermined amouNt of lining compound onto the interior surface of said bottom wall while said linear velocity is zero; d. rotating said closures after said lining compound is dispensed therein while said linear velocity is zero for a period of time sufficient to allow said lining compound to spread to the interior juncture of said bottom wall and skirt; e. at the end of said period mechanically pushing said closure along said path away from said station.

2. A method according to claim 1 wherein: f. the linear velocity of said closure is reduced to zero substantially instantaneously.

3. A method according to claim 1 wherein the rotation of said closures is effected by: f. dropping said closures vertically downward into engagement with a rotating vacuum chuck; g. maintaining said engagement for said period; and h. at the end of said period pushing said closures vertically upward thereby stripping them off said chuck.

4. A machine for dispensing a flowable material into containers comprising: a. container feeding means which continuously feeds a line of said containers onto b. one end of an elongated stationary container passageway where a substantial portion of the periphery of the containers is engaged by a first portion of the thread of c. a rotating worm gear positioned laterally adjacent the passageway such that said passageway maintains the engagement of the containers by said thread; said first portion of the thread having a constantly increasing lead angle which rapidly conveys the containers along the passageways at a constantly increasing velocity into engagement with d. a zero degree lead angle portion in the thread which temporarily stops the movement of the container along the passageway during which a predetermined amount of the flowable material is dispensed into the container from e. a flowable material dispensing means the timing of which is controlled by the radial position of the zero degree lead angle portion, and the container is engaged and spun by f. a rotating vacuum chuck positioned in the passageway opposite the zero degree lead angle portion; g. said zero degree lead angle portion being followed by a positive degree lead angle portion of the thread which extends from said zero degree lead angle portion to the other end of the passageway and which engages the container, rapidly conveys it along the passageway from the zero degree lead angle portion and discharges it from said other end of the passageway; and h. power means to drive the machine.

5. A machine according to claim 4 including: i. disengaging means for disengaging the container from the vacuum chuck immediately prior to the disengagement of the container from the zero degree lead angle portion.

6. A machine according to claim 5 wherein said disengaging means includes: j. a vertically reciprocating platform radially surrounding said chuck the reciprocations of which are controlled by the radial position of the zero degree lead angle portion whereby the platform moves upwardly immediately prior to the disengagement of the container from the 0* lead angle portion to strip the container off the chuck and downwardly to a position below the top of the chuck thereafter.

7. A machine for lining container closures comprising a bottom wall and a substantially cylindrical skirt integral with the bottom wall comprising: a. closure feeding means which continuously feeds a line of said closures onto b. one end of an elongated stationary closure passageway where a substantial portion of the periphery of the closure skirt is engaged by a first portion of a thread of c. a rotating worm gear positioned laterally adjacent the passageway such that the passageway maintains the engagement of the closures by the thread, said first portion of the thread having a constantly increasing lead angle which rapidly conveys the closures along the passageway at a constantly increasing velocity into engagement with d. a zero degree lead angle portion in the thread which temporarily stops the movement of the closure along the passageway during which sealing compound is dispensed onto the interior surface of the bottom wall of the closure from e. a sealing compound dispenser, the timing of which is controlled by the radial position of the 0* lead angle portion, and the exterior surface of the bottom wall of the closure is engaged by f. a rotating vacuum chuck positioned in the passageway opposite the 0* lead angle portion whereby the closure is spun; g. said zero degree lead angle portion being followed by a positive degree lead angle portion of the thread which extends from said 0* lead angle portion to the other end of the passageway and which engages the closure, rapidly conveys it along the passageway from the zero degree lead angle portion and discharges it from said other end of the passageway; and h. power means to drive the machine.

8. A machine according to claim 7 wherein: i. said positive lead angle portion which follows the zero degree lead angle portion has a constantly increasing lead angle whereby the closures are conveyed away from the zero degree lead angle portion at a constantly increasing velocity.

9. A machine according to claim 7 including: i. disengaging means for disengaging the closures from the vacuum chuck immediately prior to the disengagement of the closure from the 0* lead angle portion.

10. A machine according to claim 9 wherein said disengaging means includes: j. a vertically reciprocating platform radially surrounding said chuck the reciprocations of which are controlled by the radial position of the zero degree lead angle portion whereby the platform moves upwardly immediately prior to the disengagement of the closure from the zero degree lead angle portion to strip the closure off the chuck and downwardly to a position below the top of the chuck thereafter.