US3439718A

US3439718A - Rotary air-flow control valve for compound gun of crown cap lining machine

Info

Publication number: US3439718A
Application number: US634225A
Authority: US
Inventors: Norbert L Wright; Henry J Dorn
Original assignee: Continental Can Co Inc
Current assignee: Continental Can Co Inc
Priority date: 1967-04-27
Filing date: 1967-04-27
Publication date: 1969-04-22
Anticipated expiration: 1986-04-22

Description

April 22, 1969 w H ET AL 3,439,718

ROTARY AIR-FLOW CONTROL VALVE FOR COMPOUND GUN OF CROWN CAP LINING MACHINE Filed April 27, 1967 Sheet of 2 Fl g. l INVENTORS NORBERT 1.. WRIGHT BY ww w AGENT April 22, 1969 N. WRIGHT ET AL 3,439,718

ROTARY AIR-FLOW CONTROL VALVE FOR COMPOUND GUN OF CROWN CAP LINING MACHINE Sheet .3 M2

Filed April 27, 1967 AIR IN 96 EXHAUST 97 14 I3 C kl 1 2;

h INVENTORS NORBERT L. WRIGHT HENRYJDORN 5 BY @WAKW v AGENT United States Patent 3 439,718 ROTARY AIR-FLOW CONTROL VALVE FOR COMPOUND GUN OF CROWN CAP LINING MACHINE Norbert L. Wright, Park Ridge, and Henry J. Dorn,

Western Spring, 11]., assignors to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed Apr. 27, 1967, Ser. No. 634,225 Int. Cl. F16k 21/00; B32b /08; B65d 21 /12 US. Cl. 141-156 7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The invention is in the general field of automatically operating air-flow control valves for automatically controlling the operation of air cylinders.

The invention has specific application for controlling the operation of the air cylinder of a compound applying gun of a machine for lining crown caps with a thermosetting plastic liner and gasket forming compound.

DESCRIPTION OF THE PRIOR ART A typical prior art crown cap lining machine is disclosed in United States Patent 2,954,585 issued to Justin Simpson on Oct. 4, 1960. This machine employs a continuously rotating cap feed turret in the form of a circular disc with semi-circular cap retaining pockets equally spaced about its circumference. Mounted above the path of travel of the caps, in the cap feed turret, is a compound applying gun for injecting a quantity of thermocurable plastic paste into the unlined caps as the caps are carried by the feed turret. The gun is automatically actuated by means of an air cylinder associated therewith which is controlled by a solenoid operated air-flow control valve of conventional design. A timer driven by the main drive shaft of the machine delivers electrical energy to the solenoid of the air-flow control valve each time a cap arrives under the gun, which causes the gun to fire and deliver a charge of uncured plastic paste into the cap.

It was found that such a solenoid operated air-flow control valve was satisfactory for speeds up to 600 cycles per minute. However as the cyclic rate was increased to 1,100 per minute, the valve response time became erratic. The resulting variation in compound placement and quantity resulted in sub-standard product. The system required excessive maintenance and had marginal reliability.

The rotary air-flow control valve of the invention to be herein described eliminates the formerly employed solenoid operated air valve with its inherent inability to function accurately at high cyclical rates. The electrical timing means for operating the formerly employed solenoid valve has also been eliminated along with its attendant maintenance by a virtually maintenance free and relatively inexpensive flexible timing shaft which turns the rotary air valve in timed relationship with the cap lining machine.

3,439,718 Patented Apr. 22, 1969 ice SUMMARY OF THE INVENTION To overcome the problems encountered in the prior art solenoid operated compound gun cycling means, the invention provides a rotary air-flow control valve operatively associated with the air cylinder of the compound gun capable of accurately controlling the operating piston of the compound gun; hence, the firing of the gun at speeds above 1,000 cycles per minute. The rotary air-flow control valve is provided with a ported rotor through which compressed air is delivered to the air cylinder and exhausted from the cylinder in accordance with the port timing of the valve as the rotor is rotated. The rotor is mounted in anti-friction bearings and is sized to provide a clearance of 0.001 inch to 0.0015 inch with respect to the valve housing in which it rotates. This clearance is accurately maintained by the anti-friction bearings which are high precision rolling type bearings. Since there is no contact between the rotor and its housing and the rotor is mounted in high precision anti-friction rolling bearings, the rotor can be tuned very easily. This permits the use of a relatively light flexible shaft that will allow the operator to adjust the position of the gun for optimum compound placement.

A further feature of the invention is the provision of a shuttle valve disposed between the rotary air-flow control valve and the air cylinder of the compound gun. One purpose of the shuttle valve is to minimize the loss of compressed air When the machine to which the rotary valve is associated is stopped. A second combined function of the rotary air-flow control valve and shuttle valve is that they permit the machine operator to start or stop the flow of compound from the gun while the machine is running. A third function performed by these valves is to automatically cause the gun to be turned off whenever the machine is stopped. This last function is important due to the fact that the machine can stop a any random position in the cycle; therefore, it is possible for the rotary air-flow control valve to be stopped in a position that would normally cause compound to flow continuously from the gun. However, the shuttle valve Prevents the gun from remaining on and insures, by means of compressed air delivered therethrough to one side of the piston of the gun that the gun will be positively maintained in 05 position.

With the above commentary in view, it is a broad object of the invention to provide a rotary air-flow control valve of the type described operatively associated with an air cylinder to cycle the piston of the air cylinder in accorldance with the flow program porting of the control va ve.

A further object of the invention is to provide a shuttle valve interposed between the rotary valve and the air cylinder and also a valve for selectively delivering compressed air to the rotary control valve or to the shuttle valve effective to cause the piston of the air cylinder to be cycled by the rotary air-flow control valve or to be held by means of air pressure on one side thereof in a predetermined stopped position.

A still further and more specific object is to provide apparatus as immediately above described in which the air cylinder controls the operation of a gun for discharging fluid material in accordance with the program of the air-flow porting of the rotary air flow valve.

A still further and more specific object is to rpovide apparatus as set forth in the immediately preceding object associated with a machine for lining articles such as caps with a thermocurable paste-type compound, to improve the operation of the machine.

A still further object of the invention is to provide in the improved lining machine as set forth in the immedi ately preceding object a flexible drive shaft for rotating the air-flow control valve and which is driven by the machine in timing relationship with the passage of articles or caps by the gun.

Still further and more detailed objects and advantages of the invention will become apparent upon understanding the drawings and following detailed description of a preferred embodiment.

Although the invention has been presented as being air operated, other operating fluids may be employed, and the term air is intended to be broadly interpreted throughout as including other equivalent operating fluids.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a plan view partly broken away and in section of a well known type of machine for lining crown caps with a plastic liner and incorporating the improved compound applying gun control apparatus of the invention;

FIGURE 2 is a fragmentary sectional enlarged elevational view taken through the gun and control valve means along line 22 of FIGURE 1;

FIGURE 3 is an enlarged elevational sectional view taken through the rotary air-flow control valve along line 33 of FIGURE 2;

FIGURE 4 is an enlarged transverse elevational view, taken along line 44 of FIGURE 3, of the air-flow control valve, with the valve housing being omitted so as to show the porting passages of the rotor;

FIGURE 5 is a view similar to FIGURE 4 taken along the line 5-5 of FIGURE 3 and further illustrating porting passages of the rotor; and,

FIGURE 6 is a development of the circumferential surface of the rotary air-flow control valve rotor further illustrating the porting arrangement thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT The crown cap lining machine of FIGURE 1 generally designated by the numeral 10, includes a cap delivery chute generally indicated at 11 for delivering caps to an infeed turret 12 having cap receiving equally spaced semicircular pockets 13 around its perimeter. As the infeed turret rotates continuously in a counterclockwise direction, as indicated by the directional arrow thereon, unlined crown caps 14 in the turret pockets are sequentially delivered under a compound applying gun generally indicated by the numeral 15.

As each cap is positioned under the compound applying gun 15, the gun is caused to fire by the new gun control means of the invention generally indicated by the numeral 16. When the gun fires, it discharges a substantially predetermined amount of thermosetting lining compound in the form of a semi-fluid paste into an underlying cap. The paste applied into the caps 14 is in the form of a blob indicated at 17. Caps 14 having blobs of paste 17 properly positioned in the interior thereof are delivered from the feed turret into a molding turret generally indicated at 20.

Molding turret 20 has equally spaced around its perimeter a large number of liner shaping and gelling clamps generally indicated at 21 into which the caps are delivered from the infeed turret. The units 21 include a means for supporting a cap and a member for applying pressure and molding the blob of plastic 17 into the desired cap liner shape which preferably includes a peripherally disposed annular sealing gasket portion and a central portion that prevents contact between the metal of a cap and the contents of a container to which the cap will be subsequently applied. The individual cap is 7 clamped between the cap supporting member and pressure applying and molding member of a clamp unit 21 as the molding turret 20 rotates in a clockwise direction.

In order to effect the gelling of the thermosetting cap lining compound in the molding turret, suitable heating means are employed to heat the clamp units 21. Such means may be in the form of arcuate gas burner units generally indicated at 22.

Caps 14 having gelled plastic liners indicated at 23 are discharged from the molding turret 20 into a discharge turret 24. Discharge turret 24 is constructed similarly to the infeed turret 12 and as the lined caps are revolved in a counterclockwise direction in the pockets thereof they are delivered into a discharge chute 25 by a fixed diverting cam 26.

Turrets

12, 20 and 24 are driven in unison by means of a horizontal drive shaft of the machine which rotates at a substantially uniform speed. Turret 12 has 15 cap hodling pockets therein and the drive shaft 30 rotates at fifteen times the speed of rotation of the turret 12 or one revolution during the passage of each turret pocket past the gun 15. It is thus possible to directly drive the new gun control means 16 by a flexible shaft 31 coupled to the shaft 30 by a conventional coupling means 32 and to the gun control means by a similar coupling 33 so as to cause the gun to be fired only when a pocket of the turret 12 is thereunder as will be subsequently explained with reference to the other figures.

Referring to FIGURE 2 it will be seen that the gun 15 includes a housing 34 having a cylindrical bore 35 in which a piston 36 reciprocates. Attached to the bottom of the piston is a needle 37. Needle 37 reciprocates in a packing member 40 and the lower end of the needle is pointed for sealing reception in a discharge port 41 for the plastic paste. A chamber 42 formed between the packing member 40 and the discharge port 41 receives plastic paste through a conduit 43. When the piston 36 is driven downwardly the pointed end of the needle firm- 1y seats in the discharge port 41 preventing the flow of plastic paste therethrough. On the other hand, when the piston 36 is fully raised, the discharge port 41 is open so as to discharge paste into a cap 14 positioned under the gun.

The upper position of the piston 36 is adjustable by means of an adjusting screw 44 so that the size of the discharge port opening with the piston 36 in its uppermost position can be varied as desired by repositioning the adjusting screw 44 which in turn repositions the height that the needle 37 moves from a fully closed to a fully open position during operation of the gun 15. Adjusting screw 44 is threada-bly received in a plug 45, which, in turn, is threaded into the bore 35.

A passageway 46 communicates the upper surface of the piston 36 with a cylindrical bore 47 of a shuttle valve, generally indicated at 48, of the gun control means 16. A second passageway 51 communicates the lower surface of the piston 36 through the body of the shuttle valve, indicated at 52, with the rotor 53 of the rotary air-flow control valve generally indicated at 54.

A shuttle 55 fits freely in the bore 47 for vertical reciprocating or shuttling movement therein. Shuttle 55 is generally cylindrical in shape and has upper and lower cylindrical portions of reduced diameter. The upper reduced diameter cylindrical portion of the shuttle is slidably received in a bore 56 in a bushing 57 that is threadably received in the upper end of the bore 47. The lower reduced diameter cylindrical portion of the shuttle 55 is similarly slidably received in a bore 60 in the body of the shuttle valve 48. A spring 61 in the bore 60 resiliently urges the shuttle upwardly to seat an annular gasket in an upper surface thereof against a valve seat of annular configuration projecting downwardly from the bushing 57 and indicated at 62. A similar seat is provided in the body 52 of the shuttle valve and indicated at 63 against which a similar annular gasket in an undersurface of the shuttle seats, when the shuttle is forced downwardly by means of compressed air delivered through a conduit 64 into the bore 56 of the bushing 57, as will be more fully explained later.

Shuttle 55 is provided with air delivery passageways in the reduced diameter upper and lower end portions thereof through which compressed air may pass into the bore 47; the passageways being indicated at 65.

Bore 60 is in communication with the rotor 53 by means of a passageway 66. Rotor 53 is mounted for rotation in a valve housing 67 which includes a portion of the

passageways

51 and 66.

Referring to FIGURES 1 and 3, it will be observed that four threaded fasteners 70 pass through the valve housing 67 and shuttle valve body 52 and are threaded into the housing 34 of the compound applying gun 15. By means of the threaded fasteners 70, the gun 15, shuttle valve 48 and rotary air-flow control valve 54 are clamped together into a unitary structure.

Referring to

FIG'URES

2 and 3, it will be observed that the valve 54 is provided with an end plate 71 that is attached to one end of the housing 67 by means of a plurality of threaded fasteners 72. End plate 71 is provided with a central threaded opening 73 through which compressed air may be admitted through a conduit 74. End plate 71 also acts as a retainer to retain an anti-friction precision ball bearing 75 in place in the housing 67.

At the opposite end of the valve housing 67 an end plate 76 is attached by means of a plurality of threaded fasteners 77. End plate 76 similarly acts to retain a pre cision ball bearing 80 in the valve housing 67. A central bore 81 is provided in end plate 76 through which the rotor 53 freely passes.

Rotor 53 rotates within a bore 82 in valve housing 67. The rotor is sized to provide a clearance of 0.001 inch to 0.0015 inch between itself and the cylindrical wall of the bore 82.

Anti-friction

precision ball bearings

75 and 80 rotatably support rotor 53 in the valve housing 67 at spaced apart points along its length, as illustrated in FIGURE 3, for friction-free rotation therein. The rotor is turned in timed relationship with the movement of the caps in the infeed turret 12 by means of the flexible shaft 31 which is attached by the coupling 33 (FIGURE 1) to the right end portion 83 of the rotor 53, as seen in FIGURE 3. The right end of the rotor is provided with an axial bore 84 through which exhaust air flows. =Exhaust air passes from the rotor to the atmosphere through a plurality of radial bores 85 communicating with the axial bore 84.

The left end of bore 84 connects by means of a radial bore 86 to a peripheral axially extending slot which forms a valve port indicated at -87 and best seen in FIGURE 6. Slot 87 and bore -86 are also in communication with a peripheral slot '90 extending around the peripheral surface of the rotor '53 as seen in FIGURES 4 and 6.

Referring to :FIGURE 3, it will be seen that the left end of rotor 53 is also provided with an axially extending bore, indicated at 9 1. A radial bore 92 communicates the bore 91 with an axially extending peripheral slot 93 which forms a valve port. Radial bore 92 also communicates with a circumferentially extending slot 94 which is also in communication with the slot 93.

In FIGURE 2 the section is taken through the rotary valve 54 along the same plane as the section line 4--4 of FIGURE 3. However, the

passageways

51 and 66, which communicate with the rotor at points 180 rotational degrees apart are shown as lying in the same plane for the sake of clarity in illustration.

As viewed in FIGURE 2, rotor 53 rotates in a clockwise direction so as to simultaneously communicate the exhaust port 87 with the passageway 66 and the pressure port 93 with the passageway 51, as illustrated, for a short interval during each rotation of the rotor. During the major portion of the time, the exhaust slot 90 communicates with the passageway 51, while the pressure slot or port 94 is simultaneously communicated with the passageway 66.

Conduits

64 and 74 are connected to a solenoid operated 4-way valve 95. Compressed air is supplied to the valve '95 through a conduit 96 and air is exhausted therefrom through a conduit 97. A solenoid 100 is operatively associated with the valve and is energized through conductors 101 and 102. A manual control switch 103 installed in the conductor 102 is used to control the energizing of solenoid I100.

Crown cap lining machine 10 includes a drive motor 104 shown in FIGURE 2 which is energized by the conductors 101 and 102 through a double switch 105 which connects the conductors 101 and 102 with a pair of line wires.

Gun 15, associated shuttle valve 48 and rotary air-flow control valve 54 are adjustably supported on the machine 10 by means of a supporting bracket 106, the position of which can be adjusted in a conventional manner so as to position the discharge port 41 of the gun 15 at the correct location with respect to the path of travel of the caps 14 in the infeed turret 12 so that the blobs of paste 17 will be properly positioned in the caps during the operation of the machine 10.

Since the compressed air delivered to the rotary valve 54 contains a small amount of lubricating oil, it is desirable to provide an exhaust air deflecting shield .107 on the valve 54 onto which the lubricant adheres and is drained away through a conduit 110. Shield 107 also muffies the sound of escaping air and prevents stirring up of dust or dirt.

OPERATION In starting up the machine 10, the conduit 43 of FIG- URLE 2 must be connected to a supply of plastic liner forming compound under pressure so that the chamber 42 of the gun ;15 is filled with pressurized compound. Compressed air must also be available in the conduit 96 connecting to the 4-way valve 95. Switch 103 should be open so that the solenoid of the valve 95 will not be energized when the switch is now closed to energize the machine drive motor 104.

The energizing of the drive motor 104 results in the rotation of the horizontal drive shaft 30 of FIGURE 1 which effects the driving in continuous manner of the infeed turret 12, the molding turret 20, and the discharge turret 24 as indicated by the directional arrows. During each full revolution of the shaft 30 a cap 14 will be presented under the gun 15 and the rotor 53- of the rotary airflow control valve 54 will be rotated a full turn by the shaft 30 by means of the flexible shaft 31. Fourway valve 95 is of the type having a spring biased air-flow control spool that is positioned to deliver compressed air through the conduit 64 to the shuttle valve 48 and to exhaust air through the conduit 74 from the rotary valve 54 when the operating solenoid :100 is not energized. When compressed air is thus delivered to the conduit 64 and exhausted to atmosphere through the conduit 74, the shuttle 55 is driven downwardly against the force of the spring 61 by air pressure which acts on the upper reduced diameter cylindrical portion of the shuttle. As the shuttle is driven downwardly, the gasket in the lower large diameter flat surface thereof seals on the valve seat 63 so as to prevent entrance of compressed air from the conduit 64 into the bore 60- and through the connecting passageway 66 to the rotary valve 54. Since shut tle 55 fits loosely in the cylindrical bore 47, compressed air from the conduit 64 will pass easily through the clearance space between the periphery of the shuttle and the wall of the bore 47 so that air under pressure will enter the passageway 46 communicating with the upper surface of the piston 36 of the gun 15. The compressed air acting on the upper surface of the piston 36 will maintain the piston in its lowermost position at which needle 37 is seated in the discharge port 41 so as to prevent the discharge of compound through the discharge port. The space below the piston 36 will be exhausted to atmosphere via the passageway '51 through valve 54. This exhausting of the space under the piston 36 will occur even if the rotor 53 is in a stopped position at which it would normally block off the exhausting of air through the passageway '51. Should the rotor be so stopped, the air will escape through the clearance space provided between the periphery of the rotor 53 and the cylindrical wall of the bore 82. The gun cannot thus become airbound and the needle 37 will always be caused to positively seat in the discharge port 41 when air pressure is applied to the upper surface of the piston 36 regardless of the position that the rotor 53 may be stopped at. Thus, as long as compressed air is supplied to the valve 95 through the conduit 96 and the switch 103 remains open to maintain the solenoid 100 in a de-energized condition, the gun 15 will remain positively shut otf.

Once the machine is brought up to normal operating speed by the motor 104 the gas burners 22 may be turned on. The liner and gasket shaping and gelling units 21 are heated as they move past the gas burners to bring them up to normal operating temperature.

When conditions are stabilized, the gun 15 is caused to be actuated by the closing of switch 103. This has the effect of energizing solenoid 100 which repositions the airflow control spool of the valve 95 so that compressed air is directed through the valve 95 into the conduit 74 and the conduit 64 is exhausted to atmosphere through the valve 95 and exhaust conduit 97. The release of pressure in conduit 64 immediately permits the spring 61 of of the shuttle valve 4 8 to raise the shuttle into seating engagement with the valve seat 62 to prevent the escape of compressed air that enters the bore 47 through the conduit 64.

Compressed air is delivered through the conduit 74 to the rotary valve 54 through the threaded opening 73 in the end plate 71. The air passes through the

bores

91 and 92 into the .

slots

93 and 94 so that the

slots

93 and 94 will be constantly supplied with compressed air. On the

other hand slots

87 and 90 of the rotor 53 will always be in communication with the atmosphere through the

bores

86 and 84 and radial bores 85. Compressed air will be delivered through the slot 94; passageway 66; bore and passageway 46 into the bore 35 of the gun 15 to act on the upper surface of the piston 36 to maintain the needle 37 seated in the discharge port 41 for the greater portion of the time it takes the rotor 53 to make a full revolution. At the same time that pressure is being applied above the piston 36, air will be exhausted from under the piston 36 through the passageway 51, exhaust slot or port 90 and exhaust bores 86, 84 and 85. In this manner the gun 15 is retained in an off position for a major portion of the time it takes the rotor 53 to make a single revolution.

There will be a time, however, during the rotation of the rotor 53 when the axial slot or port 87 is in communication with the passageway 66 and the slot or port 93 is in simultaneous communication with the passageway 51. When the rotor 53 is in this position, as illustrated in FIGURE 2, compressed air will be exhausted from above the piston 36 through the passageway 46; bore 60; passageway 66 and through the exhaust port 87 to the atmosphere. Simultaneously, compressed air will be delivered through the port 93 and passageway 51 to the underside of the piston 36 causing the piston to be raised until it makes contact with the bottom of the adjusting screw 44. This results in the lifting of the needle 37 a predetermined amount from its seated position in the discharge port 41. The unseating of the needle 37 permits plastic paste to be delivered from the chamber 42 through the discharge port 41. If caps are not being delivered to the machine through the cap delivery chute 11, at this time, the plastic paste will be delivered through an empty pocket 13 in the infeed turret 12 into a suitable receptacle (not shown) stationarily positioned beneath the turret 12 directly under the gun 15. If caps are now delivered to the turret 12 from the infeed chute 11, the otherwise wasted blobs of plastic are received in the desired position within each cap; the blobs being indicated at 17 in FIGURE 1,

As soon as the relatively

narrow ports

87 and 93 are no longer in communication with the

passageways

66 and 51, respectively, the

passageways

51 and 66 again are simultaneously communicated with the

slots

90 and 94, respectively, which results in compressed air being evacuated from below the piston 36 through the passageway 51 and slot 90 and being applied above the piston 36 through passageway 66; bore 60; lower passageway in shuttle 55 and passageway 46. This results in the piston 36 being urged downwardly until the needle 37 again seats in the discharge port 41 to terminate the delivery of plastic paste therethrough.

Any time during the operation of the machine 10 the machine operator can prevent the gun 15 from operating by merely opening the manual switch 103. This results in the solenoid 100 of 4-way valve 95 in being de-energized. The spring biased air-flow control spool of the valve 95 is, as a result, moved by the spring to the position whereat conduit 74 is exhausted to atmosphere and compressed air is delivered into the conduit 64 to the shuttle valve 48. This air pressure is applied against the small diameter upper end portion of the shuttle 55, that slides in the bore 56 causing the shuttle to be forced downwardly against the pressure of the biasing spring 61 to seat on the lower valve seat 63. Compressed air flows through the bore 56 into the passageway 65 in the upper reduced diameter end portion of the shuttle then into the bore 47 and around the shuttle 55 in the clearance space maintained between the peripheral surface of the shuttle and the wall of the bore 47 into the passageway 46; then into the bore 35 above the piston 36 to drive the piston downwardly and seat the needle 37 in the discharge port 41. The seating of the shuttle on the valve seat 63 prevents compressed air from going into the bore 60; through the passageway 66 and being exhausted through the rotor 53 to the atmosphere. The closing of the valve 63 thus insures that sufficient pressure is maintained above the piston 36 to prevent leakage of paste from the gun 15 around the needle 37 and also effects the saving of compressed air that would otherwise be wasted by passage out through the rotor 53. As long as the switch 103 is maintained closed, the gun 15 will not fire.

The amount of plastic delivered into the caps 14 may be adjusted to a degree by raising or lowering the adjusting screw 44 which controls the amount of opening of the discharge port 41 during operation. The pressure of the plastic paste in the chamber 42 may also be adjusted as desired by conventional pressure regulating means to also regulate the amount of plastic contained in each of the blobs 17 emanating from the gun 15.

Due to the clearance space maintained between the rotor 53 and the valve housing 67 of the valve 54, there will be a certain amount of air leakage from the

high pressure slots

93 and 94 over to the

atmospheric pressure slots

87 and 90, but this leakage is relatively small and does not adversely affect the operation of the valve 54. There is no sliding contact of the rotor 53 in the housing 67, as the rotor rotates in its anti-friction bearings and which permits the flexible rotor drive shaft 31 to be a very flexible low-power transmitting type. Due to the ease of flexibility of this type of flexible shaft there is no problem adjusting the position of the gun with respect to the path of travel of the caps in the infeed turret 12 for optimum placement of the paste in the caps.

As the caps having blobs of plastic 17 properly located therein are delivered into the molding turret 20 from the infeed turret 12 they are clamped in the liner shaping and gelling clamp units 21 wherein pressure is applied to the thermocurable plastic and it is molded into a desired liner shape, and heat-gelled as the caps revolve in the molding turret. Caps having gelled plastic liners 23 are discharged from the molding turret 20 into a discharge turret 24 from which they are deflected into a discharge chute 25 by the cap diverting cam 26.

In the event that the switch 105 is opened to completely de-energize machine 10, the solenoid 100 will also be deenergized so that the gun is held in an off position. In the event that there is a failure in line power, the gun 15 will also be maintained in the shut-off position and the control 16 of the invention is thus a fail-safe type.

Although the gun and the control system therefor in accordance with the invention is illustrated as being associated with a machine for lining crown-type bottle caps, such a gun and associated control system may be used in other environments where precise operation of the gun is necessary at high cyclic rates. For example, a gun controlled in accordance with the invention may be employed to extrude or spray on a protective lacquer coating along freshly-soldered or welded side-seams of can bodies as they are conveyed in spaced apart single file processional order through a side-seam soldering or welding machine at high production rates.

Since the invention is susceptible of being employed in various environments and in forms that may vary somewhat from the illustrated preferred embodiment, it is not intended that the invention be limited to the specific details of the illustrated embodiment but rather only as set forth in the following claims.

We claim:

1. In a machine for applying fluid material to articles which includes: a gun for discharging fluid material, said gun having an air cylinder including a movable piston that controls the operation thereof; means for conveying articles sequentially past said gun for receiving fluid material discharged by said gun, and means for driving said article conveying means; the improvement comprising: a rotary air-flow control valve operatively associated with said air cylinder; said air-flow control'valve including a housing having a bore; a rotor rotatably mounted in said bore; said rotor "having compressed air passageways and exhaust air passageways; said housing having air-flow passageways that sequentially communicate with said rotor passageways as said rotor rotates in said bore; said housing air-flow passageways communicating with said air cylinder on opposite sides of the movable piston for admitting and exhausting compressed air into said cylinder to move said piston back and forth as said rotor rotates; means for rotating said rotor; said rotor rotating means being driven by said article conveying said drive means in timed relationship to the passage of articles past the gun, causing the gun to be operated only at times when an article is in position to receive fluid material from said gun, and means for supplying compressed air to said compressed air passageways of said rotor.

2. The improvement as set forth in claim 1 further characterized in that said rotor is mounted in precision anti-friction bearings and is sized to provide a clearance in the order of 0.001 inch to 0.0015 inch between itself and the wall of said bore which is accurately maintained by said precision bearings.

3. The improvement as set forth in claim 2 further characterized in that said means for rotating said rotor is a flexible shaft.

4. The improvement as set forth in claim 1 further characterized in that a shuttle valve is provided; an air supply valve is also provided to selectively deliver compressed air to said rotary air-flow control valve and exhaust said shuttle valve or to exhaust said rotary air-flow control valve and deliver compressed air to said shuttle 10 valve; said shuttle valve having a first opening having a valve seat defined therearo'und; said shuttle valve having a second opening having a valve seat defined therearound;

said shuttle valve having a bore in communication with said first and second openings thereof; a shuttle in said bore for shuttling between said valve seats to close said first opening and open said second opening when said shuttle is in a first position and to open said first opening and close said second opening when said shuttle is in a second position; said second opening being in communication with one of said housing air-flow passageways communicating with said air cylinder on one side of said piston and normally permitting the passage of air therethrough between said rotary air-flow control valve and said cylinder during operation of said cylinder; said shuttle valve having means to resiliently bias said shuttle to its first position to close said first opening, whereby: when compressed air is delivered from said supply valve to said shuttle valve and exhausted from said rotary air-flow control valve compressed air passageways, said shuttle is moved by air pressure to its second position at which it closes said second opening and opens said first opening to supply compressed air through said first opening to said one side of said piston causing said piston to positively maintain said gun in an off condition and preventing loss of compressed air through said second opening and said rotary air-flow control valve.

5. The improvement as set forth in claim 4 further characterized in that said rotor is mounted in precision anti-friction bearings and is sized to provide a clearance in the order of 0.001 inch to 0.0015 inch between itself and the wall of said bore which is accurately maintained by said precision bearings.

6. The improvement as set forth in claim 5 further characterized in that said means for rotating said rotor is a flexible shaft.

7. In combination: an air cylinder including a movable piston; a rotary air-flow control valve operatively associated with said air cylinder; said air-flow control valve including a housing having a bore; a rotor rotatably mounted in said bore in precision anti-friction bearings; said rotor being sized to provide a clearance in the order of 0.001 inch to 0.0015 inch between itself and the wall of said bore which is accurately maintained by said precision bearings; said rotor having compressed air passageways and exhaust air passageways; said housing having air-flow passageways that sequentially communicate with said rotor passageways as said rotor rotates in said bore; said housing air-flow passageways communicating with said air cylinder on opposite sides of said movable piston for admitting and exhausting compressed air into 2,954,585 10/1960 Simpson.

HOUSTON S. BELL, 111., Primary Examiner.

US. Cl. X.R.