Can Closing Machine

Exemplary arrangements relate to can closing machines. Exemplary arrangements relate to can closing machines that produce a continuous double seam that joins a can lid to a can body in fluid tight relation. Specifically, exemplary arrangements relate to can closing machines that have the capability to join lids to standard cans as well as to join lids to cans that have reduced weight and wall thickness.

Can closing machines, which are alternatively referred to herein as can seamer machines, operate to join can lids and can bodies in fixed fluid tight relation by forming a continuous double seam. The seam in combination with a sealing compound which is often applied to the seam area of the lid or can body prior to engagement with the can, assures production of an air tight seal. The formation of the air tight seal helps to preserve the product inside the can.

Can closing machines are shown in U.S. Pat. Nos. 3,465,703; 6,623,230; and 6,926,486 the disclosure of each of which is incorporated herein by reference in its entirety.

Can closing machines commonly run at high rates of speed. It is common for such machines to close at least 1000 cans per minute and often 1800 cans per minute or more. The high speeds of the mechanisms which operate in such machines apply significant force to the cans to accomplish the can closing operations.

Beverage and other cans are often comprised of aluminum. Aluminum is a valuable material. The use of cans that have less aluminum can help to conserve this valuable material. However producing the same size can using less aluminum requires reducing the thickness of the material in areas of the can body that causes the can to have a lower column strength compared to a standard can. Efforts to close cans that are reduced in weight using existing can closing machines at current normal operating speeds often results in damage to the cans and/or unsatisfactory seam formation.

Existing can closing machines may benefit from improvements, including improvements that will enable such machines to close standard cans and weight reduced aluminum cans while operating at current high operating speeds.

Exemplary arrangements relate to high speed can closing machines that operate to close reduced weight aluminum cans at high processing rates comparable to those achieved for standard cans that are not weight reduced. Such exemplary arrangements produce fluid tight double seams which join a respective can body (which is alternatively referred to herein as the can) and a can lid while operating at a high speed and without causing damage to the can body or the can lid. For purposes of this disclosure a high speed can closing machine is defined as a can closing machine that operates to close at least 1000 cans per minute.

Exemplary arrangements include a can closing machine with a rotatable turret. The turret includes a plurality of circumferentially angularly spaced can closing stations at its radially outer periphery. Each can closing station operates to join a can body and a can lid in fluid tight relation by producing a continuous double seam during less than one complete rotation of the turret.

Each can closing station includes a lower chuck. The lower chuck includes a can supporting platform that is configured to support a bottom end of a can body. The can supporting platform rotates about a chuck axis. The can supporting platform is selectively vertically movable relative to the turret.

Each closing station further includes an upper chuck. The upper chuck is rotatable about the chuck axis in coordinated relation with the can supporting platform such that the upper chuck rotates in the same rotational direction and at the same rotational speed as the can supporting platform. The upper chuck is configured to be vertically immovable relative to the turret. The upper chuck is configured to engage a can lid that is positioned to close an opening at an upper end of the can body.

Each exemplary can closing station further includes a pair of seaming rolls. With the can lid positioned to close the opening and in engaged relation with the upper chuck, and the can bottom engaged in axially aligned relation with the can supporting platform of the lower chuck, the seaming rolls are operative responsive to rotation of the can body and lid to produce a continuous double seam which joins the can body and lid in fluid tight relation.

The exemplary lower chuck includes a spring loaded vertically movable piston that is in operative connection with the can supporting platform. The piston is configured to operate as a guide and to move both rotationally and vertically in an upper sleeve that is in fixed operative connection with the turret. The exemplary lower chuck further includes a chuck shaft that is in operative connection with a central chuck gear. The chuck shaft and can supporting platform are rotationally driven through the chuck gear.

An upper portion of the chuck shaft is in fixed rotational connection with the piston. The piston extends in contacting surrounding relation of the upper portion of the chuck shaft and is relatively axially movable relative to the chuck shaft along the chuck axis.

A lower portion of the chuck shaft extends in a cylindrical cavity of a slider. The slider extends in a lower sleeve that is in fixed operative connection with the turret. At least one bearing extends radially between the lower portion of the chuck shaft and the slider. The lower chuck includes a vertical actuator which is operative to selectively vertically move and position the slider and the can supporting platform. The exemplary vertical actuator includes a cam roller that extends in journalled relation between a pair of disposed legs on the slider. The cam roller is in engagement with a stationary lifter cam that controls the vertical position of the platform, can body and lid as the lower chuck rotates with the turret.

The exemplary can closing machine operates so that the combined vertical momentum produced through upward movement of the lower chuck, the can, the can lid and the can contained material at the time that the can lid engages the upper chuck, is maintained below a threshold. Maintaining the momentum below the threshold as well as controlling the vertical speed at the time of engagement of the lid and the upper chuck, and the rate of increase in axially acting force that is applied to the can body and lid immediately after lid engagement with the upper chuck, reduces the risk of damage to a weight reduced can and/or producing a flawed seam.

The exemplary can closing machine further includes at each can closing station a mechanism that causes the can body and lid to maintain alignment with the chuck axis. The exemplary mechanism operates reduce the risk of can wobble which corresponds to a portion of the can body being off-center relative to the chuck axis as the can body and lid are moved upward by the lower chuck toward engagement with the upper chuck. Exemplary arrangements include a knockout pad that is configured to engage the can lid prior to engagement with the upper chuck. The knockout pad applies an axially centered downward directed force on the can lid and can body. The downward force is of a suitable magnitude to urge the can body to maintain centered alignment with the chuck axis in the event that can wobble begins to occur.

The exemplary high speed can closing machine further includes additional features and relationships which are discussed in the following Detailed Description and shown in the appended drawings.

Referring now to the drawings and particularly tothere is shown schematically therein a high speed can closing machine generally indicated. The exemplary can closing machine includes a turret. The turret rotates about a turret axis. The turretrotates about the turret axis in a first rotational direction generally indicated T.

The exemplary turret includes a plurality of can closing stations. The can closing stations are located in angularly spaced relation about an outer periphery of the turret. The exemplary turret includescan closing stations each of which is configured to join a can body and a can lid in fluid tight relation through the formation of a continuous seam in a manner that is later discussed. In some exemplary arrangements the turret is configured to rotate at a speed of at least 90 rpm and to produce seams on at least 1600 cans per minute. An alternative exemplary arrangement of a can closing machine is configured to operate with the turretrotating at a speed of at least 100 RPM and to produce at least 1800 sealed cans per minute. Some exemplary machines may operate to close at least 2200 cans per minute. In exemplary arrangements the cans are aluminum cans that house contained material such as a beverage or other food for human or other animal consumption. Such cans commonly hold between 8 and 16 ounces of material. Of course it should be understood that these cans are exemplary and in other arrangements other types of cans, can sizes and/or types of can contained materials may be used.

The exemplary can closing machine operates in connection with a rotatable lid feeding turret. The exemplary lid feeding turretincludes a plurality of uniformly angularly spaced pockets. The exemplary lid feeding turret includes a number of pockets that corresponds to the number of can closing stations on the turret. Each pocketis configured to hold a can lidwhich is shown in phantom. Lid feeding turretrotates in a second rotational direction indicated L which is opposed of the first rotational direction in the exemplary arrangement. During operation of the machine, can lids are fed into the pockets such that each pocket holds a can lid as the lid feeding turret moves the lid into a make up positionin which the lid is placed in closing relation of an upper opening of a respective can body.

Can bodies such as can bodyshown, are delivered to the turretby a can feed conveyor. In the exemplary arrangement cans are moved through engagement with movable can engaging projections. In exemplary arrangements the cans that are moved by the can feed conveyorinto engagement with the turretare filled with a beverage or other can contained material that is to be sealed within the can body, but each can body has a respective upper opening that is configured to be closed by a lid that is delivered in the makeup position.

The exemplary can closing machine operates to receive the can body including the can contained material and the lid at the can closing station corresponding to the makeup positionand moves the can and lid in a manner like that later discussed in detail to produce a continuous fluid tight double seam that joins the can body and lid in sealed relation. The seams are formed in less than one rotation of the turret. The sealed cans are then engaged with a take away turret. Cans are guided into a station at the periphery of the take away turretat a position. The cans as represented by a can, are then moved with the take away turret which rotates in the second rotational direction, as indicated by the arrow O, in guided relation with a curved guideto an output position. Of course it should be understood that this configuration is exemplary and in other arrangements other devices and configurations may be used.

As can be appreciated the can closing machineoperates to reliably and accurately join lids and can bodies without causing damage to the can body or the seam. The speed and force of the components which operate to form the seams which join the can bodies and lids can result in significant forces being applied both vertically, tangentially and rotationally to the can bodies.shows examples of damaged cans which may have malformed seams that can result from excessive or improperly applied forces, improper set up or other factors during operation of the can closing machine. The effects of the type shown incan particularly arise when a can closing machine that has been set up for handling standard aluminum cans with can bodies with a column strength (meaning vertical column strength without sustaining permanent deformation such as buckling, of the vertically extending annular outer can side wall) of approximately 675 N (150 pounds), is operated to close aluminum can bodies which have been gauge reduced and include a thinner can side wall such that the can bodies have a column strength of approximately 550 N (120 pounds). As used herein the reference to an approximate column strength of a can body shall mean the column strength indicated, plus or minus 10%. As can be appreciated the production of scrap material results in losses that exceed any benefit that is achieved by reducing the amount of aluminum included in the can bodies.

The exemplary can closing machine is configured to operate reliably in closing aluminum cans with standard can bodies that have a higher column strength as well as cans with can bodies that include less material and which have a lower column strength.

In the operation of the exemplary arrangement each can closing stationincludes a lower chuck. The lower chuck includes a can supporting platform. The can supporting platformis configured for engaging a bottom endof a can bodywhich is similar to can body, in axially centered relation. The can supporting platformis rotatable about a chuck axis. The can supporting platformis also selectively movable vertically relative to the turret.

Each can closing stationfurther includes an upper chuck. The upper chuckis configured to be in a fixed vertical position and rotates in coordinated relation with the can supporting platform. The upper chuck rotates in the same rotational direction and at the same speed as the can supporting platform. In exemplary arrangements the can supporting platform and the upper chuck each rotate in an opposed rotational direction from the rotational direction of the turret. Further in an exemplary arrangement when the turret rotates at about 100 RPM about the turret axis, the can supporting platform and the upper chuck rotate about the chuck axisat about 2000 RPM. Of course this configuration is exemplary and in other arrangements other approaches and parameters may be used.

The exemplary upper chuck is configured to engage a can lid such as can lidwhich is similar to can lid. As previously discussed the can lid is configured to close an upper openingof the can body. As shown inin the exemplary arrangement an upper annular peripheral flangeextends radially outwardly and in continuous surrounding relation of the can opening. The can lidincludes a continuous annular peripheral portionthat in the undeformed position extends above and in radially outward overlying relation of the flange.

The exemplary can closing stationfurther includes a knockout pad. As later discussed in detail, the knockout padis axially centered with the chuck axis and operates to apply a downward force on the upper side of the can lidprior to lid engagement with the upper chuck. The knockout padapplies a force which opposes the upward movement of the can lid and can body until the can lid is engaged with the upper chuck. The knockout padalso rotates in coordinated relation with the upper chuck and the can supporting platform to help maintain the lid and the can body in relatively fixed positions prior to the seam being produced.

Each can closing station further includes at least one seaming roll. In exemplary arrangements each can closing station includes a first seaming rolland a second seaming roll. The can closing machine operates the seaming rolls in the manner described in the incorporated disclosures to cause a continuous fluid tight double seam to be produced through deformation of the annular peripheral portion of the can lidand the upper annular peripheral flangeof the can body.

In the exemplary arrangement the first seaming rollis selectively moved to operatively engage the peripheral portion of the lidand the peripheral flangeof the can body, so that responsive to rotation of the can body and can lid about the chuck axis, an initial seam configuration is formed. In the exemplary arrangement the first seaming rollis operative to cause in axial cross section, the annular peripheral portion of the lid to extend around the annular peripheral flange of the can body. An example of an initial seam configuration which is caused to be formed by the first seaming rollis shown in.

In the exemplary arrangement after the initial seam configuration is formed through operation of the first seaming roll, the can seam is then selectively operatively engaged by the second seaming roll. As represented inthe second seaming roll acts to cause the continuous double seam to be further formed and radially inwardly compressed as the can body and can lid are rotated about the chuck axis. The action of the second seaming rollalong with a layer of sealing compound that is applied on the peripheral portion of the lid and/or peripheral flange of the can body prior to engagement with the seaming rolls, produces a continuous fluid tight double seam, an exemplary final configuration of which is shown in. As represented in axial cross section in, in the fully formed condition of the continuous seam, three layers of the lid material are pressed into abutting engagement with two layers of the can body material to produce the final seam. Of course it should be understood that this approach is exemplary and other arrangements other approaches may be used.

An exemplary lower chuckis shown in greater detail in. The exemplary lower chuck is configured to have a mass that is substantially less than some other lower chucks that have been used in can closing machines. The reduced mass configuration provides significant advantages in terms of enabling more precise control of vertical displacement, velocity and momentum of the can supporting platform and the can supported thereon. These capabilities of the exemplary arrangement reduce the risk of damage particularly to weight reduced aluminum cans during the can closing process.

In the exemplary arrangement the lower chuck includes a central chuck gear. The chuck gear is in centered relation with the chuck axis. In the exemplary arrangement the chuck gear is configured to rotate in response to engagement with an annular stationary gear as the turret and the lower chuck rotate about the turret axis. Of course this approach to providing rotation of the lower chuck is exemplary and in other arrangements other rotational drives may be used.

The chuck gearis in operative fixed connection with a chuck shaft. In some exemplary arrangements the chuck shaft may be integrally formed with the chuck gear. The chuck shaftincludes an upper portionand a lower portion. The chuck shaft upper portion includes an axially centered recess. A coil type compression springextends in aligned relation with the chuck axis and a lower end of the spring is in nested relation within the recess.

A pistonwhich serves as a vertical guide includes an axially centered cylindrical cavity. The upper portion of the chuck shaftextends in the cavitysuch that an inner annular wallof the cavityof the piston extends in contacting annular surrounding relation of the upper portion of the chuck shaft. The exemplary pistonincludes a pair of opposed axially elongated slotsat a lower end. A respective pinextends in a respective axially elongated slot and is in threaded engagement with the upper portion of the chuck shaft. As a result in the exemplary arrangement the piston is in fixed rotational connection with the upper portion of the chuck shaft and is axially movable relative to the upper portion of the chuck shaft.

The exemplary pistonincludes an axially extending threaded openingthat extends vertically above the cavity. The threaded openingis configured to receive therein a spring adjusting screw. The exemplary spring adjusting screwis selectively axially positionable in the threaded openingthrough rotation of the screw. The inner end of the spring adjusting screwis in engaged relation with a centering washer. The exemplary centering washeris configured to extend within the central portion of the coils of compression springand provide a uniform horizontal surface that engages the inner face of the spring adjusting screw. The exemplary spring adjusting screw is configured to be selectively axially positioned to provide a preload force on the compression spring. The set preload force operates to require that the axially downward force acting on the compression spring must exceed the preload before the compression spring will begin to deform. Of course it should be understood that this approach is exemplary and in other arrangements other approaches may be used.

The exemplary pistonis axially centered in an upper annular sleeve. Sleeveis in fixed operative connection with the turret. In the exemplary arrangement the sleeveincludes an annular outward projection which is operative to vertically position the sleeve in an opening in the turret. A gasketand an o-ringare operative to cause the upper sleeveto be in sealed connection with the opening.

In the exemplary arrangement the upper sleeve includes an annular bushingthat is positioned in radially intermediate relation between an outer surface of the pistonand an upper sleeve inner surface. The piston is rotationally and axially movable relative to the upper sleeve while in contacting relation with the annular bushing. A capextends in overlying relation of the top of the upper sleeve. A sealextends below the capand radially intermediate of the piston and the upper sleeve. The exemplary sealhelps to prevent loss of lubricant that is delivered to the area of the bushing radially intermediate of the piston and the sleeve in the manner that is later discussed.

The exemplary pistonincludes an axially centered upward extending annular projection. The projectionextends above and in surrounding relation of the threaded opening. A sealextends radially and in surrounding relation of the projection. The exemplary projectionextends in an opening in a shield. The exemplary shieldextends above and in outwardly overlying relation of the top of the pistonand the vertically extending sides of the upper sleeve. At least one annular shimextends in underlying relation of the shieldand in surrounding relation of the central projection. The can supporting platformextends in overlying relation of the shieldand is held in releasably attached connection therewith by releasable fasteners. In exemplary arrangements the one or more shimsare usable to precisely set the vertical position of the upper surface of the can engaging platform.

The exemplary configuration of the pistonand upper sleeveenable the piston to be vertically and rotationally movable while in contacting relation with the upper sleeve. This enables the can supporting platformto be both vertically and rotationally movable relative to the sleeve. The exemplary construction further enables the piston while in contacting relation with the upper portion of the chuck shaft to be axially movable relative to the chuck shaft against the biasing force of the compression spring. This exemplary configuration enables the piston to serve as a guide that provides for precise positioning and movement in the rotational and vertical directions of the can supporting platform, while having significantly less mass than structures used in some prior can closing machines.

In the exemplary arrangement the configuration of the pistonand the coils of the compression springreduce the risk of vibration and chatter caused by the axial and rotational movement of the piston relative to the upper sleeveand the rotational movement of the lower chuck with the coils of the compression spring therein. The exemplary pistonhas a radially outer annular piston surfacethat is relatively rotatable and axially movable while in contacting engagement, with the bushing of the upper sleeve. The maintenance of contacting engagement of the piston with both the upper portion of the shaftand the upper sleeveas the piston undergoes rotational and axial movement avoids radial play and minimizes the risk of vibration and chatter despite high-speed rotation and the application of axial and radial forces. Further in the exemplary arrangement the diameter of the outer piston surfacebeing greater than the outer diameter of the coils of the expression spring, and in the exemplary arrangement being at least twice the outer diameter of the coils of the compression spring, helps to further reduce the risk of force imbalance that may cause vibration resulting in can damage and malformed can seams.

Further the exemplary arrangement is configured to handle cans the bottom ends of which commonly include a radially inward tapered lower shoulder that extends to an annular downward facing bottom wall that surrounds a vertically upward extending central can dome. Such can bottom ends have an annular vertically extending can dome surface that radially outwardly bounds the can dome and radially inwardly bounds the downward facing can bottom wall. While the can is axially centered on the can supporting platform of the lower chuck, the annular vertically extending can dome surface is radially inboard of the annular outer piston surface. In this arrangement the piston outer diameter is greater than the can dome diameter of the vertically extending can dome surface. Having the piston diameter associated with the annular outer piston surface greater than the can dome diameter, and having the can dome diameter greater than the coil spring outer diameter, maintains proper component alignment and balance during the lower chuck operation which achieves more stable, vibration free and chatter free operation of the lower chuck during can closing and seaming operations.

The exemplary lower chuck further includes a slider. The exemplary sliderincludes an axially centered cylindrical cavity. The lower portionof the chuck shaft extends in the slider cavity. At least one bearingis positioned in the slider cavity and operatively extends radially intermediate of the chuck shaft and the slider. In exemplary arrangements the at least one bearingincludes a plurality of bearings configured to prevent relative axial and radial movement between the slider and the chuck shaft. Of course this approach is exemplary and in other arrangements other bearing approaches may be used.

The exemplary sliderincludes a pair of disposed downward extending legs. Each of the legsincludes an opening that is configured to receive a shafttherein. A cam rolleris rotatable on the shaftin intermediate relation of the legs. As a result the cam roller is mounted in journalled relation on the slider. In the exemplary arrangement a releasable retaineris used to hold the shaftand the cam rollerin position. However it should be understood that in this exemplary arrangement the retainermay be released so that the cam roller is removable from engagement with the slider.

The exemplary slider includes an axially centered access openingthat is positioned above the cam roller. A removable access coveris configured to close the access opening in fluidly sealed relation. With the cam roller and the access coverremoved, a removable retaineris accessible through the access opening. The retaineris configured to engage the lower portionof the chuck shaftand hold the chuck shaft in a fixed axial position relative to the slider, while enabling the shaft to rotate relative to the slider and in the slider cavity. Of course it should be understood that this arrangement is exemplary and in other arrangements other approaches for holding the shaft in relatively rotatable engagement with the slider may be used.

A lower annular sleeveextends in surrounding relation of the slider. The lower sleeveis in fixed operative connection with the turret. The lower sleeveis configured to enable the slider to move while in contacting relation with the lower sleeve vertically along the chuck axiswithin the lower sleeve. This arrangement further provides radially playless relative vertical movement of the lower sleeve and the slider.

In the exemplary arrangement a further cam rolleris mounted in journalled relation with the shaft. In the exemplary arrangement the cam rollerand the further cam rollerof the lower chuck are operatively engaged with a lower chuck vertical actuator. The exemplary vertical actuator is operative to cause selective vertical movement and positioning of the can supporting platform. This is accomplished in the exemplary arrangement by engagement of the cam rollerwith the stationary lifting canof the machine. The further cam rolleris in operative engagement with a stationary hold down camof the machine. In the exemplary arrangement lower chuck vertical actuator includes the lifting cam and the hold down cam which are each respective annular stationary cams which extend at each can closing station and with which the respective cam roller and hold down roller of the upper chuck may remain engaged throughout rotation of the turret.

However it should be understood that this lower chuck vertical actuator configuration is exemplary and in other arrangements other types of vertical actuators may be used. These may include for example hydraulic or electrical motors or other drives that selectively move gears, pistons, screws or other components to provide the desired vertical positions, velocities, acceleration and other properties to components of the lower chuck and the can supporting platform.

The exemplary lower chuck further includes components which provide the delivery of lubricant to the areas where lubrication is needed. In the exemplary arrangement an impellerextends in the slider cavity. The exemplary impeller is in fixed rotational connection with the lower portion of the shaft through a key. The exemplary impeller includes an external helical grooveconfigured to move lubricant therein in a downward direction with rotation of the chuck shaft. The impeller and the groove thereof extend within a pump ring. In the exemplary arrangement a pair of annular wave springsextend axially intermediate of the pump ringand the bearings. A snap ringis positioned axially above the pump ring and is operative to hold the pump ring in position.

In the exemplary arrangement the chuck shaftincludes a shaft lubricant passagethat extends axially therein. The lubricant passage is in fluid communication through a central opening in the retainerwith the bottom portion of the slider cavity. The lubricant passage is also in fluid communication with the cavityin the piston. Radially extending piston lubricant passagesextend outwardly from the cavityand are configured to deliver lubricant to the area of the bushingand radially intermediate of the outer surface of the piston and the inner surface of the upper annular sleeve.