Patent ID: 12251888

DETAILED DESCRIPTION

FIG.1A-1Cillustrate a reciprocating sealer for web converters, according to various embodiments of the present subject matter.FIG.1Aillustrates a web100traveling in a direction represented by arrows101. Those of ordinary skill in the art will understand upon reading and comprehending this disclosure, how to use the reciprocating sealer with various web and product arrangements. The illustrated web can include product between a bottom web and a top web or can include a web folded longitudinally in the direction of web travel to provide the folded web with a bottom folded portion, a top folded portion and product therebetween. The system includes a first plate assembly102A with a first base103A, a first seal plate104A, and a first linear servo motor to provide a linear motion of the first seal plate with respect to the first base, as illustrated by arrows105A. A second plate assembly102B includes a second base103B a second seal plate104B, and a second linear servo motor to provide a linear motion of the second seal plate with respect to the second base, as illustrated by arrows105B. At least one plate assembly motor is operably linked to the first base103A and the second base103B to provide a linear motion, as illustrated by arrows106A and106B, of the first and second plate assemblies toward each other to perform a sealing operation and away from each other. The illustrated linear motion106A-B of the first and second plate assemblies is substantially orthogonal to the linear motion105A of the first seal plate with respect to the first base and the linear motion105B of the second seal plate with respect to the second base. A controller is connected to the at least one plate assembly motor and to the first and second linear servo motors to coordinate the motion of the first and second seal plates to perform a seal operation on a web while traveling with the moving web. Thus, for example, the controller is able to control the velocity of the web and the horizontal velocity of the seal plates to match the seal plate velocities to the web velocity during a seal operation. In some embodiments, the controller receives a signal from a sensor or sensors, indicative of the web velocity, or receives a communication signal informing the controller of the web velocity.FIGS.1B-1Cillustrate the results of a sealing operation. The web100illustrated inFIG.1Brepresents the web at107, and the web100illustrated inFIG.1Crepresents the web at108. As illustrated inFIG.1C, the sealed web100includes sealed margins109surrounding pouches110containing a product. The specific seal depends on the tooling used in the seal plates.

FIG.2illustrates an embodiment of a seal plate motion profile. The seal plates are illustrated as104A and104B inFIG.1A, for example. The illustrated motion profile211can be implemented when the web is moving and passing between the plate assemblies. The profile211includes a motion profile204A for the first or top plate assembly104A, and a motion profile204B for the second or bottom plate assembly104B. In the illustrated example, as the plates move from left to right, the plates move into operational contact with the web to perform a sealing operation, as illustrated by the heat seal dwell time, and then move away from the web. The plates return, moving from right to left in the illustrated example, where the motion profile begins again. Thus, the profile illustrates a reciprocating motion. The profile may include parameters describing a dwell time, a closing ramp, an opening ramp, and a velocity. The dwell time dictates the amount of time the seal plates will remain engaged together to seal the web. The open and closing ramp parameters dictate the acceleration with which the controller will move the plate assembly servo motor to either open or close the seal plates. The velocity parameter dictates the maximum velocity at which the controller attempts to move the plate assembly servo motor when opening and closing the seal plates. The specifics of the profile, such as dwell time, the closing ramp, the opening ramp, the velocity, may be programmed into the controller.

FIG.3illustrates a perspective view of a sealer embodiment. A controller312is adapted to communicate with the sealer313to provide motion instructions to the motors, to provide heating instructions to the heating elements of the seal plate assemblies and to receive various feedback signals. The controller also monitors the motion of the web passing between the seal plates of the sealer to initiate and coordinate the sealer motion. In various embodiments, signals indicative of web motion370are received by the controller from either an axes integral to the controller, and providing the motion to move the web, or a sensor detecting the web motion, such as an encoder or a resolver. In the illustrated embodiment, visible components of the sealer313include support legs314, lower tie bars315, upper tie bars317, and frame members316. The illustrated embodiment also provides a view of some of the components that provide the clamping motion of the seal plates. These components include a plate assembly servo motor337, mechanically coupled to a pair of shafts323through two gearboxes333(one gearbox is shown in the illustrated view). Each shaft is coupled to four tie arms, with two tie arms318coupled to the first seal plate assembly328and two tie arms319coupled to the second seal plate assembly329. Each seal plate assembly is also mounted to the sealer frame through a plurality of linear bearings. Each tie arm is coupled to shaft323through an offset cam322and linkage such that when the shaft is rotated, the heat seal plates move apart in opposite directions.

FIGS.4A-4Billustrate a perspective view and an exploded view, respectively, of an embodiment of a sealer frame assembly. The illustrated frame assembly includes support legs414. Lower tie bars415connect side frames416toward the bottom of the frames and are further connected to the support legs414. Upper tie bars417connect side frames416toward the top of the frames. The illustrated assembly includes tie arms419, which may be referred to herein as tie bars419to move the second plate via mounting block421and tie arms418, which may be referred to herein as tie bars418, to move the first plate assembly connected via mounting block420. The tie bars419and tie bars418include apertures to receive eccentric cams422, which are adapted to receive a drive shaft423. The eccentric cams in tie bars418are 180 degrees out of phase with respect to the eccentric cams in tie bars419such that the first and second plate assemblies move in a complementary fashion (e.g. either moving simultaneously toward or simultaneously away from each other) when the drive shaft423is rotated. Those of ordinary skill in the art would understand upon reading and comprehending this disclosure that other mechanical linkages could be used to provide the complementary motion of the first and second seal plate assemblies. Various bearings and other hardware are illustrated to provide for a smooth operation of the linkage. Linear bearings424and linear bearing rails425are also illustrated. In the illustrated example, the rails425are attached to the frames416, and the bearings424are attached to the mounting blocks420and421to provide a substantially vertical, linear path of motion for the first and second plate assemblies. The drive shaft423extends through pillow block ball bearings426, which are attached to the tie bars415of the frame assembly via mount427. Thus, the axis of the drive shaft is fixed, and the rotation of the eccentric cams422for the tie bars418and419causes the tie bars, and thus the upper and lower plates, to move with respect to the frame assembly.

FIG.5illustrates an exploded view of a system embodiment, including the sealer frame assembly ofFIG.4A, first and second plate assemblies, and a plate assembly motor. Illustrated are a first seal plate assembly, or upper plate seal bed528, and a second seal plate assembly, or lower plate seal bed529. Also illustrated are an upper heat sink530attached to the upper plate seal bed528and a lower heat sink531attached to the lower plate seal bed529. The seal beds528and529are linked to the tie bars using mounting blocks520and521, respectively, also illustrated as420and421inFIG.43. Electrical boxes532are provided for use in providing the control wiring to the seal beds. Reducer gear boxes533are connected to drive shafts523. The gear boxes533are connected to the frame using an isolation pad534and a mounting plate535. A floating coupling536links the gears boxes533. A plate assembly servo motor537is connected to the gear boxes. Thus, the servo motor accurately rotates the drive shafts523, which accurately moves the seal beds528and529through the eccentric cams. The plates can be moved through a large number of incremental positions between a maximum distance and minimum distance from each other. The maximum distance depends on the dimensions of the eccentric cam and other mechanical linkages.

FIGS.6A-6Billustrate a front view of a sealer embodiment in a partially open and a close position, respectively. The figure illustrates the tie bars618and619, the drive shafts623, and the eccentric cams622for tie bars618. The eccentric cams for ties bars618are 180 degrees out of phase such that tie bars618move in a complementary fashion with respect to tie bars619. The frame assembly is designed with symmetry to balance the complementary forces. The figure also illustrates the linear bearings624and rails625used to guide the vertical motion of the seal beds to provide the vertical motion in the motion profile illustrated inFIG.2. InFIG.6B, the drive shafts623are shown rotated about 45 degrees, from their position inFIG.6A, to simultaneously raise the tie bars619and the second seal plate assembly629, and lower the tie bars618and the first seal plate assembly628.

FIGS.7A-7Billustrate perspective views andFIG.7Cillustrates an exploded view of an embodiment of a first seal plate assembly. The seal plate assembly includes a base738. Linear bearing rails739are attached to the base, along with stop blocks740and bumpers741to limit the linear motion of a servo motor magnet744. The linear bearing rails are included to support and guide the horizontal motion profile illustrated inFIG.2. A linear servo motor742is attached to the base738. Linear bearings743are attached, along with the linear servo motor magnet744, to a magnet mount745. The linear bearings743allow the servo motor magnet744and magnet mount to glide along the bearing rails739. An isolation plate753is connected to the magnet mount745. A heated plate755, with inserted heater rods756, is connected to the isolation plate. A thermocouple757is also illustrated, the heater rods756and the thermocouple757are electrically connected to the controller to facilitate a close looped heating system. A tooling plate761is held in place, next to the heated plate, between a pair of tooling guides759and is further secured with an operator side tooling clamp bar758and a machine side tooling clamp bar763. Clamping handles749, hex shaft750, hold down clamps752and hold down clamp mounts751cooperate to secure the operator tooling clamp bar758and machine side tooling clamp bar763. The operator side tooling clamp bar758is further secured with a pair of hand tightened bolts762. The hand tightened bolts762extend through clearance holes in the operator side tooling clamp bar758and thread into the heated plate755. In various embodiments, spring loaded detent pins764, installed in the machine side tooling clamp bar763, spring loading the tooling plate761in the cross web direction. The hand tighten bolts762secure the tooling plate761, against the spring loaded detent pins764. Further engagement of the tooling plate against the spring loaded detent pins764allow fine adjustment of the position and alignment of the tooling plate761with respect to the web.

FIGS.8A-8Billustrate a perspective and exploded view, respectively, of an embodiment of a second seal plate assembly. The seal plate assembly includes a base838. Linear bearing rails839are attached to the base, along with stop blocks840and bumpers841to limit the linear motion of a servo motor magnet. A linear servo motor842is attached to the base838. Linear bearings843are attached, along with the linear servo motor magnet844, to a magnet mount845. The linear bearings843allow the servo motor magnet844and magnet mount to glide along the bearing rails839. Air bladder hard stops846are attached around a periphery of mount845, and an air bladder847is positioned over the mount. An air bladder back plate848is attached to the hard stops846. An isolation plate853and seal plate spacer854are positioned over the air bladder back plate848. A heated plate855, with heater rods856, are positioned over the seal plate spacer. A thermocouple857is also illustrated, the heater rods856and the thermocouple857are electrically connected to the controller to facilitate a close looped heating system. A tooling plate861is held in place, next to the heated plate, between a pair of tooling guides859and is further secured with an operator side tooling clamp bar858and a machine side tooling clamp bar863. Clamping handles849, hex shaft850, hold down clamps852and hold down clamp mounts851, cooperate to secure the tooling clamp bar858. The tooling clamp bar is further secured with a pair of hand tightened bolts862. The hand tightened bolts862extend through clearance holes in the operator side tooling clamp bar858and thread into the heated plate855. The tooling clamps858can be released and hand tightened bolts862and tooling clamp bar removed allowing the tooling plate861to be slid out between the tooling guides859. In various embodiments, spring loaded detent pins864, installed in the machine side tooling clamp bar863, spring load the tooling plate861in the cross web direction. The hand tighten bolts862secure the tooling plate861, against the spring loaded detent pins864via the operator side tooling clamp bar. Further engagement of the tooling plate861against the spring loaded detent pins864allow fine adjustment of the position and alignment of the tooling plate861with respect to the web.

In the illustrated embodiment, an air bladder, or bladders, are used to even pressure across the entire plate. Some embodiments provide an air bladder in the first or upper seal plate assembly, some embodiments provide an air bladder in the second or lower seal plate assembly, and some embodiments provide an air bladder in both the first and second seal plate assemblies. The illustrated embodiment provides the air bladder only for the bottom seal bed. The air bladder is filled, and rests on hard stops until the upper plate contacts the lower plate, pushing the lower seal plate off the hard stops. The seal pressure is controlled by the pressure of the bladder.

FIGS.9A-9Billustrate linear motion of a seal plate assembly929using linear servo motors. The illustrated embodiment inFIG.9Ashows a seal plate assembly929where the seal plate is at or near one end of its linear travel range. InFIG.9A, the linear motor942and a portion of the linear motor magnet944are visible. Also visible is a portion of the linear bearing rails939. InFIG.9B, the illustrated embodiment of the seal plate assembly ofFIG.9Ais shown at or near the opposite end of its linear travel range. The linear motor942is no longer visible.FIGS.9A-Bgenerally show embodiments of the second seal plate assembly. The motion of embodiments of the first seal plate assembly operate on the same principles as that of the second seal plate assembly.

FIG.10illustrates a flow diagram for a process of operating the sealer, according to various embodiments. The process flow is controlled by logic programmed into the controller. Those of ordinary skill in the art will understand upon reading and comprehending this disclosure how the flow diagram corresponds to the motion profile illustrated inFIG.2. The process begins when the sealer is initialized1001. In various embodiments, initialization1001includes preheating the seal plates, setting and verifying the motion profiles for each of the servo motor axes, setting the seal air pressure, setting the seal dwell time and enabling or disabling the operation of the sealer or a portion thereof. After initialization1001, the machine controller will monitor whether the sealer is enabled1002. In various embodiments, if the sealer is not enabled, the machine controller will stop any linear motion of the sealer and move the plate assembly servo motor (337inFIG.3) to a position maximizing the distance between position of the seal plates assemblies1012. If the sealer is enabled, the axes will need to be “homed”1013before the normal cyclical motion can take place. “Homing”1013allows the machine controller to reference the position of the servo axes with a physical location. In various embodiments, the physical reference is determined by moving each of the axes until the axis triggers a reference switch. The machine controller monitors the position of the axis when the reference switch is triggered. The machine controller in various embodiments, references subsequent motion from the position of the axis when it triggered the switch.

Once homed, the motion control monitors an axis indicative of the web motion, and initiates and coordinates the motion of the sealer with respect to the motion of the web. The first coordination task initiates a repeating process which controls the motion of the seal plate assemblies to accelerate and match the horizontal speed with the speed of the web1004. The motion controller monitors the position of the seal assemblies. When the seal assemblies move past a “close” trigger position1005, the machine controller will initiate and control the motion of the plate assembly servo motor to move the seal plates toward each other to clamp the web between the seal plates1006. With the web clamped between the seal plates, the machine controller begins a seal dwell timer1007. In various embodiments, the machine controller then monitors events to initiate opening the seal plates. In various embodiments, the termination of the seal dwell timer1009functions as the event to trigger opening of the seal plates. However, in various embodiments, if the seal dwell is set too long, the seal plates will open when the linear motors used to move the seal plates near the end of the linear travel, even if the seal time has not expired (i.e. seal time set too long or web moving too fast). As the linear motors approach the end of their travel, the task initiated in step1004stops the linear motors and moves them back to their initial position for the start another seal cycle. The sealer will continue to cycle until the sealer is disabled1011.

FIGS.11A-11Cillustrate a method of removing seal plate tooling according to various embodiments.FIG.11Aillustrates the operation of the clamping handles1149to release the tooling clamp bar1158.FIG.11Billustrates the removal of the tooling clamp bar1158. The tooling clamp bar1158is removed after unthreading two bolts1162that are used to hold the tooling clamp bar near the heat plate. After removal of the tooling clamp bar,FIG.11Cillustrates the removal of the tooling plate1161. The tooling plate1161is removed by sliding the plate out of the slots in tooling guides1159. Installation of a tooling plate is achieved by repeating the process in the reverse order. The cam action clamps1149provide the ability to change upper and lower seal plates, regardless of whether the seal plates are cold or hot. The ability to change hot seal plates reduces changeover times, as operators do not have to wait for the tooling to cool.

The present subject matter is capable of sealing a web while the web is traveling. The present subject matter provides repeatable and consistent seal times for the seal operation. The servo driven motors provide multiple open positions. The sealer is able to accurately control the position of the seal beds, thus controlling the seal times.

Some embodiments, as discussed above, use one or more air bladders to distribute pressure across the plate and provide an even seal pressure. Some embodiments, as discussed below, use one or more air cylinders to distribute pressure across the plate and provide an even seal pressure.

FIGS.12A-12Cillustrates perspective views of a plate assembly embodiment with at least one air cylinder. For example the embodiment of the plate assembly1270illustrated inFIGS.12A-12Cmay replace the seal plate assembly illustrated inFIGS.8A-8B. Rather than using an air bladder847as illustrated inFIG.8B, the embodiment illustrated inFIGS.12A-12Cuses at least one air cylinder1271(seeFIG.12B). The remainder of the plate assembly embodiment, not illustrated inFIGS.12A-12C, may be similar to the components of the embodiment shown inFIGS.8A-8C.

The embodiment of plate assembly1270illustrated inFIGS.12A-12Cincludes horizontal motion hard stops1271mounted to the base1238. These hard stops1271function to limit the horizontal motion of the plate assembly1270on the base1238. Encoders, such as optical or magnetic encoders, may be used to detect the position of the plate assembly1270on the base1238. The illustrated plate assembly1270also includes cams1272and cam followers1273that cooperate with each other to promote a stable alignment of components that make the plate assembly1270.

FIG.12Billustrates two air cylinders positioned on the magnet mount1245. In the illustrated embodiment, both air cylinders have an equal diameter and are symmetrically positioned on the magnet mount1245. For example, the magnet mount1245may have a width and length where the length is about twice the width. The diameters of the air cylinders are slightly less than the width of the magnet mount. In some embodiments, the air cylinder(s) have a short stroke length less than 0.2 inches. For example, the air cylinder(s) may have a stroke length within a range of about ⅛ inch to about ⅙ inch.

FIG.13illustrates a perspective view of the plate assembly embodiment without a back plate. The figure illustrates air cylinders1371on the magnet mount1345. In the illustrated embodiment, the mount1345has a generally rectangular footprint with a periphery defined by parallel long sides and parallel short sides. Rails1374are positioned along the parallel long sides. The figure also illustrates air cylinder hard stops that include cooperating mount elements1375and back plate elements1376. The mount elements1375are mounted to the magnet mount1345. The back plate elements1376are mounted to a back plate. The mount and back plate elements1375and1376have complementary stepped surface to contact each other to limit a separating motion between the mount1345and the back plate. In the illustrated embodiment, the hard stops include three parallel back plate elements1376, where a first one of back plate elements is positioned along one of the short sides, a second one of the back plate elements is positioned along the other one of the short sides, and a third one of the back plate elements is centered between the first and second back plate elements. The mount elements1347of the hard stops cooperate with the back plate elements1346to limit the separating motion between the mount1345and the back plate. The hard stops and the peripheral rails define air cylinder areas on the mount1345in which the air cylinders are positioned. The figure also illustrates cams1372, which were illustrated at1272inFIG.12.

One of the cams may be formed from a structural element, and this structural element may have an opening through which pneumatic hoses1377may be passed to provide pressurized air to the air cylinders1371. In the illustrated embodiment, this structural element is centered on a long side of the mount1345. A break between rails1374provides room for the hoses1377.

FIGS.14A-14Billustrate a bottom and side view of an embodiment of an air cylinder. In some embodiments, the air cylinder(s)1471have a short stroke length less than 0.2 inches. For example, the air cylinder(s) may have a stroke length within a range of about ⅛ inch to about ⅙ inch. The illustrated air cylinders have a cylindrical shape with a circular foot print. The air cylinder fills substantially all of the space in the air cylinder areas on the mount defined by the rails1374and mount elements1376, as illustrated inFIG.13. In some embodiments, the air cylinders have a diameter of about 12 inches, a cylinder bore of about 10.5 inches and a height of about 1 to 2 inches. However, other sizes may be used for a particular design. The air cylinders can be mounted (e.g. bolted) to at least one of the mount or the back plate.

FIG.15illustrates an exploded view of the plate assembly embodiment with the at least on cylinder. The figure illustrates the mount1545and back plate1548, which are similar to the mount845and back plate848illustrated inFIG.8.FIG.15is intended to illustrate differences between the mount1545and1548back plate, which have been discussed above.FIG.15also illustrates the cooperating stepped surfaces of the mount elements1547and the back plate elements1546.

One of ordinary skill in the art will understand that, the modules and other circuitry shown and described herein can be implemented using software, hardware, and combinations of software and hardware. As such, the illustrated modules and circuitry are intended to encompass software implementations, hardware implementations, and software and hardware implementations.

The methods illustrated in this disclosure are not intended to be exclusive of other methods within the scope of the present subject matter. Those of ordinary skill in the art will understand, upon reading and comprehending this disclosure, other methods within the scope of the present subject matter. The above-identified embodiments, and portions of the illustrated embodiments, are not necessarily mutually exclusive. These embodiments, or portions thereof, can be combined.

In various embodiments, the methods provided above are implemented as a computer data signal embodied in a carrier wave or propagated signal, that represents a sequence of instructions which, when executed by a processor cause the processor to perform the respective method. In various embodiments, methods provided above are implemented as a set of instructions contained on a computer-accessible medium capable of directing a processor to perform the respective method. In various embodiments, the medium is a magnetic medium, an electronic medium, or an optical medium.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiment shown. This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. Combinations of the above embodiments as well as combinations of portions of the above embodiments in other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.