SYSTEM FOR PROCESSING CARTRIDGES

Abstract

A filling system for filling cartridges with a variety of outer diameters includes a conveyor having cleats extending at spaced intervals. A shifting mechanism is coupled to the conveyor for shifting the conveyor between a first position and a second position. The distance between the first and second positions is a function of the outer diameter of the cartridge to be filled.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional filing claiming priority under 35 U.S.C. 119 from provisional application Ser. No. 60/876,655, filed Dec. 22, 2006, the entirety of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The invention relates generally to automated systems used in the packaging of silicones, sealants, adhesives and the like into cartridges, having applications in a variety of industries including, but not limited to, the building, medical and automotive sector.

Within industry, cartridges have been designed to package and house a single material formulation, and are generally described as tubular with one open end and one closed end that incorporates a nozzle or nozzle attachment feature for later dispensing. A material formulation is disposed of into the interior of the cartridge followed by a plunger assembly, which seals the container with the dual purpose of containing the material and providing a piston to extrude the material out the nozzle on the closed end of the cartridge. Technological advancements have produced solutions to applications that require two material formulations to be housed within a single cartridge having a multiplicity of segregated cavities, while maintaining the formulations in isolation from each other until the point of use.

Cartridges come in a variety of sizes that vary in both diameter and length and are typically defined by their capacity to hold a maximum volume of material. For a sector of industry, cartridges are typically broken up into two families of products identified as quarts or pints, each of which are identified by a range of diametrical dimensions (inner and outer) and a range of lengths. In addition to dimensional differences, cartridges can vary in material construction and are typically grouped into those manufactured of plastic, fiber (pressed paper), or metal (aluminum). Depending on the cartridge material construction, an appropriate plunger design is selected to seal off the cartridge open end. The type of material contained within the cartridge, the eventual product application as well as marketing considerations can dictate the size of the cartridge (pint or quart), the material construction of the cartridge (plastic, fiber or aluminum), and the plunger to be used (plastic or aluminum).

Manufacturers of sealants, adhesives and the like, as well as re-packagers of the same, require automation to facilitate in the manufacturing of cartridges, which may include dispensing and filling, application of traceability data, sealing and packaging. In the development of automated systems, considerations are given to the physical size and shape of the cartridge being processed, the physical and chemical properties of the material formulation being dispensed, the environmental conditions (including available power requirements), and other factors that may affect machine performance. In a typical application a dispensing nozzle is initially placed within the inner diameter, and at the bottom of, the cartridge. Material is then pumped through the inner diameter of the dispensing nozzle and into the interior of the cartridge. As material is deposited into the closed end of the cartridge, the relative position between the dispensing nozzle and cartridge is increased, resulting in the region between the cartridge and dispensing nozzle being displaced with material dispensed from the dispensing nozzle. Subsequent to this operation the cartridge is indexed to a station whereby a plunger is inserted into the open end of the cartridge and bottomed out against the material surface. Ordinarily, a mechanical feature is incorporated into the plunger insertion station, enabling the atmospheric venting of the gas trapped between the plunger and material during processing, although plunger designs are offered that obsolete this need. The cartridge is further processed for optional processing steps such as seaming of the plunger, dispensing of desiccant packs, application of lot numbers, and the like.

Optionally, cartridges can be supplied with plungers pre-inserted and bottomed out against the closed end of the cartridge. In this fashion filling of the cartridges is performed from the closed end of the cartridge, and as material enters the cartridge body, the pre-inserted plunger is displaced and moved out toward the direction of the open end of the cartridge. This approach has its limitations, as it requires that the closed end be resealed after filling, and the cartridge construction and design allow for the plunger to move in both directions.

Various systems and methods have been designed to meet the range of market needs for automation, with a family of solutions focusing on high viscosity materials, while another focus has been low viscosity materials (a.k.a. self-leveling materials). The high yield stress of thixotropic formulations, allows for development of dispensing automation on a horizontal platform given their resistance to spillage over time intervals associated with indexing cartridges between the point of dispense/fill and plunger insertion. Although appropriate for high viscosity formulations, horizontal filling and processing is inappropriate for self-leveling formulations given their tendency to pour out of the cartridge when tilted beyond a critical angle. Self-leveling formulations have given rise to the development of vertical filling systems, aptly suited for such materials but as an added benefit can also process high viscosity formulations.

Manufacturing platforms developed to process self-leveling formulations have gravitated towards rotary dial indexing mechanisms equipped with hard tooling (a.k.a. nests) mounted to the rotating dial plate to position the cartridge within the indexing mechanism. The nests are designed to accommodate the physical cartridge dimensions such as outer diameter and overall length, material out of which the cartridge is constructed, and the presence or absence of any cartridge nozzle features. The nests are disposed peripherally around the circumference of the rotary dial plate, and are positioned such that, when the rotary dial plate is indexed through the various stations, the longitudinal axis of each nest is coincident to that of each and every station. The tooling (i.e. nests) is necessary to maintain and assure proper alignment of the cartridge relative to each station through which the cartridge has to be processed. However, the cartridges may be one of a range of lengths and diameters, depending on their intended use. Nests are built to accommodate a specific tube size. In an effort to accommodate a certain level of flexibility towards tolerating a range of cartridges diametrical and length differences, nests are made interchangeable and can be exchanged with ones designed to the specific physical characteristics of each cartridge desired to be processed on one system. This level of flexibility, however, is associated with high tooling fabrication costs and inefficient changeover efficiencies, as nests must be replaced each time a tube of differing diameter or length is to be filled resulting in reduced machine uptime.

Accordingly, a cartridge filling assembly which overcomes the shortcomings of the prior art is desired.

BRIEF SUMMARY OF THE INVENTION

The invention relates to an automated system for processing a range of cartridges having a range of different lengths and diameters without the need for removing, or adding dedicated tooling. The premise of the system is to obsolete the need to require absolute alignment of the cartridge as the cartridge is being transported/indexed and to only impose the necessary alignment at each processing point (i.e. each station) in a manner that does not require retooling.

A cleated indexing conveyor, powered by a motor, is positioned on its side, such that the cleated indexing conveyor belt surface is at a right angle to the machine surface. The cleats are spaced at predetermined spacings along the length of the conveyor such that the largest cartridge in outer diameter loosely fits between a pair of consecutive cleats. A pair of supporting rails is positioned alongside and parallel to the conveyor belt such that any cartridge seated between two consecutive cleats remains trapped by the cleats and rails, but is free to move within the confines of the conveyor belt, cleats and supporting rails. In this manner cartridges can be indexed, without maintaining any accurate alignment, yet will not tip beyond a critical angle

At each processing station, an alignment fixture is positioned and selectively activated to accurately align the cartridge body along its longitudinal axis with the filling nozzle. The alignment fixture is a V-block mounted to an aligning pneumatic cylinder, such that when energized the cartridge is seated into the V-block and pressed against the conveyor belt surface thus immobilizing the cartridge, and aligning the cartridge longitudinal axis parallel relative to the axis of delivered material, but not necessarily coincident. Given two diametrically different cartridges (e.g. a pint cartridge and a quart cartridge), their longitudinal axes will be offset from one another by one-half the difference of their respective outer diameters, as mathematically expressed in EQUATION 1.

offset=½(OD₂−OD₁) [e.g. offset=½(OD_quart−OD_pint)]  [EQUATION 1]

In order to complete alignment of the cartridges with the processing stations and to simultaneously make parallel and coincident the cartridge longitudinal axis with the axis of delivered material, either the cartridge must be shifted forwards or backwards by the offset amount, or alternatively, the station itself must be shifted forwards or backwards by the offset amount. Given the complexity in offsetting all processing stations, it becomes preferable to maintain the processing stations stationary and to instead shift the cartridges normal to the conveyor belt surface to complete cartridge alignment relative to the station.

To this end, the cleated indexing conveyor is mounted by mounting legs to hardware incorporating linear bearings enabling the cleated indexing conveyor to be positioned in a multiplicity of locations normal to the conveyor belt surface. A shuttling pneumatic cylinder locked to the hardware allows for the cleated indexing conveyor to be desirably shifted backwards or forwards. As such the cleated indexing conveyor can be appropriately positioned for diametrically different cartridges such that the respective cartridge longitudinal axis remains coincident to the filling material centerline axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a top plan view of a cartridge filling system and associated cleated indexing conveyor with a discrete number of shuttle mechanisms constructed in accordance with the invention.;

FIG. 2 is a side elevation view of a shuttle mechanism and alignment fixture constructed in accordance with the invention in a pre-activation position;

FIG. 3 is a side elevation view of an alignment fixture in an activated position constructed in accordance with the invention;

FIG. 4 is a side-by-side comparison of side elevation views of an alignment fixture and shuttle mechanism with a cartridge of a first diameter prior to alignment and an alignment fixture accommodating a larger diameter cartridge in accordance with the invention.

FIG. 5 is a side by side comparison of side elevation views of an alignment fixture and shuttling mechanism with a cartridge of a first diameter in alignment with a larger diameter cartridge in accordance with the invention; and

FIG. 6 is a comparison of a top plan view of a cleated indexing conveyor with an exemplary representation of the V-block mechanism used for aligning the cartridge longitudinally of two different diameters in accordance withy the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, FIG. 1 illustrates a cartridge filling system generally indicated as 103 for filling cartridges of various diameters and lengths in accordance with the present invention. It is contemplated that filler system 103 may be used to fill any cartridge 104 or other article of manufacture. Filling system 103 includes an indexing conveyor 105 portion for conveying and delivering cartridges to individual processing stations 106, such as a filling station (not shown), desiccant dispensing station; plunger insertion station, seamer station or lot number applicator station, etc.

The cleated indexing conveyor 105 may be any standard container mover known to those skilled in the art that is mounted on its side and incorporates cleats 107 at spaced intervals to enable the movement of vertically positioned cartridges 104 along the length of cartridge filling system 103. Cleats 107 may take the form of paddles as shown, or may be extended rods or other structure which defines a space and prevents cartridge 104 from extending beyond a tipping angle.

The cleated indexing conveyor 105 is powered by an appropriate motor 108 operatively connected thereto, such as an AC/DC motor (geared or otherwise), stepper motor, servomotor, air motor or any mechanism that translates linear motion into rotary motion. Supporting the cleated indexing conveyor 105 along its length, are one or more shuttle mechanisms 110 which enable the shifting of said cleated indexing conveyor 105 between positions closer or farther away from an axis of a filling nozzle for dispensing material (not shown) of filling system 103.

Reference is now made to FIG. 2 showing shuttle mechanisms 110 in greater detail. Shuttle mechanism 110 incorporates a hollow cross member 201 with a forward linear bearing 202 affixed to one end, and a rear linear bearing 203 affixed to the other end. Extending perpendicularly to the hollow cross member 201 are both a conveyor mounting member 204 and a conveyor support member 205. A pair of conveyor mounting legs 206 are affixed to and extend away from mounting member 204 in a direction relatively parallel to hollow cross member 201. Cleated indexing conveyor 105 is mounted to conveyor mounting legs 206. The conveyor support member 205 supports the weight of cleated indexing conveyor 105.

A shaft 207 is positioned through linear bearings 202 and 203 and the hollow cross member 201. A shaft collar 208 is positioned at one end of shaft 207 and a rear shaft collar 209 (pictured in FIG. 6) positioned on an opposed end of shaft 207. Shaft 207 is further locked in position by a pair of shaft support blocks 210 at either end which in turn are mounted onto a rear assembly mount 211 and forward assembly mount 212 respectively. Forward assembly mount 212 and rear assembly mount 211 are mounted to a framework 213 of cartridge filling system 103. In this way, shuttle mechanism 110 is securely affixed within filling system 103 to anchor shuttle mechanism 110 therein.

As described, shuttle mechanism 110 shifts cleated indexing conveyor 105 between a forward position whereby the forward linear bearing 202 moves towards forward shaft collar 208 until contacting shaft collar 208 (so that collar 208 acts as a stop), and a rear position whereby the rear linear bearing 203 moves towards the rear shaft collar 209 until contacting shaft collar 209 (so that collar 209 acts as a stop). A shuttling pneumatic cylinder 214 is mounted to the rear assembly mount 211 and coupled to the hollow cross member 201, via a suitable coupling mount 215 as known in the art.

The activation and deactivation of pneumatic cylinder 214 effects the shifting of shuttle mechanism 110 between the rear and forward positions as defined by the stops provided by forward shaft collar 208 and rear shaft collar 209. The controlled activation and deactivation of pneumatic cylinder 214 moves the assembly of shuttle mechanism 110. One end of pneumatic cylinder 214 is fixed at assembly mount 211 while the others are directly coupled to pneumatic cylinder 214 by coupling mount 215. The remainder of the assembly is affixed to hollow tube 201 and slides along hollow cross member 201 as pneumatic cylinder 21 moves cross member 201 along shaft 207.

It is well understood that the length of movement of shuttle mechanism 110 is variable as stop 208 may placed anywhere along the shaft to accommodate what amounts to an infinite variety of sized cartridges 104. As will become readily apparent below, with proper control of pneumatic cylinder 214, hollow cross member 201 can be moved any increment of distance along shaft 207 positioning shuttle mechanism 110 at any point between the forward position and the rear position. Additionally, although the shifting of shuttle mechanism 110 is described as being enabled by the shuttling pneumatic cylinder 214, it is possible to achieve the same result via any linear power transmissive mechanical assembly.

A pair of low friction strips 230 are disposed on framework 213 and enable the smooth movement of cartridge 104 along the length of the cartridge filling system 103. Additionally, a pair of supporting rails 240 is positioned along the length of the cleated indexing conveyor 105 in facing relationship therewith. Accordingly, representative cartridge 104 is maintained within a region defined by the successive cleats 107 of cleated indexing conveyor 105 and the pair of supporting rails 240. The space is greater than the volume of the largest expected cartridge 104, but sufficiently small to support cartridge 104 therein in an orientation approximating an orientation for filling, i.e. Cartridge 104 is not maintained in complete and accurate alignment however it is prevented from tipping over and possibly spilling its contents.

An alignment fixture 220 is mounted to frame 213 in facing relationship with cleated indexing conveyor 105. Alignment fixture 220 includes a pneumatic cylinder 221. A V-shaped block 222 is affixed to the cylinder so that the arms of the V are in facing relationship with cleated indexing conveyor 105 and moves between a first position away from cleated indexing conveyor 105 to a second position toward cleated indexing conveyor 105 under the control of pneumatic cylinder 221.

Referring now also to FIG. 3, the V-block 222 of the alignment fixture 220 is activated via the aligning pneumatic cylinder 221 to press the cartridge 104 disposed between cleats 104 of cleated conveyor 105 against the cleated indexing conveyor 105. The preferred embodiment of pusher block 222 is V-shaped, although any angled or curved surface having two opposed substantially symmetrical arms would suffice. As a V-shaped block moves towards cartridge 104, either arm of V-shaped block 222 engages cartridge 104 towards the back closed recess of the V so that cartridge 104, no matter what diameter or shape, eventually engages both arms of the V-shaped block 222 and becomes oriented to be in a generally upright direction (generally parallel to conveyor 105, generally orthogonal to strips 230 and parallel to a plane formed by guide rails 240). As seen in FIG. 3, when fully extended, V-shaped block 222 pins cartridge 104 against conveyor 107 to maintain cartridge 104 in the desired position. As such, the cartridge 104 is positioned in complete alignment relative to all interfacing tooling and processing equipment. Given the geometry of the V-block 222, stroke length of the aligning pneumatic cylinder 221 and the region defined by the cleated indexing conveyor 105, cleats 107, and supporting rails 240, cartridges of variant geometries (shapes and sizes) can be accommodated such that the entire range of sizes can be positioned with complete vertical alignment.

Reference is now made to FIG. 4 in which a first shuttle mechanism 110, prior to positioning a cartridge 104a is compared to a second shuttle mechanism 110b positioning a second cartridge 104b of greater outer diameter prior to alignment for explanation of operation of the invention. Like numerals are utilized to describe like parts, the primary difference between cartridge 104a and 104b being the outer diameter of the cartridge; there really being no difference between shuttle mechanism 110a and 110b in FIG. 4.

Although not shown, in conventional cartridge filling machines, the filling nozzle from which the material flows into the cartridge is at fixed position relative to cleated indexing conveyor 105 and/or alignment fixture 220. In order for most efficient filling of the cartridge, it is preferred in the art that a center axis of empty cartridge 104 be substantially coaxial with the central axis of flow of the material to be filled.

However, the relative position of shuttling mechanism 110a relative to filling system 103 is the same as the relative position of shuttling mechanism 110b. Because the outer diameters of 104a and 104b are different, prior to alignment, as they are presented to filling system 103, a central axis 401 of cartridge 104a is offset from a central axis 405 of cartridge 104b by an offset gap 402. If not corrected for, then the filling nozzle of the filling system 103 would be offset relative to one of cartridges 104a, 104b by gap 402, which is undesired.

Reference is now made to FIG. 5 in which a first mechanism 110a is again compared to a second mechanism 110b showing a shifting mechanism 110 to align axis 405 with axis 401 to remove the offset. Again, like numerals are utilized for like structures for ease of description. Prior to orientation by alignment fixture 220, axis 401 is aligned with axis 405 by shifting mechanism 110 shifting the conveyor belt to align a central axis of the cartridge with the filling station.

Rather than move the larger diameter cartridge 104b, it is preferred to move the smaller diameter cartridge 104a into the appropriate position. During operation, cylinder 214 is activated moving hollow cross member 201 along shaft 207 towards the forward shaft collar 208 until stopped by shaft collar 208, in this example.

At this point, given the relative diameters, central axis 401 is now aligned with central axis 405 while, as expected, a trailing edge of conveyor support member 204 for shifting mechanism 110a is offset by a gap 502 relative to the trailing edge of support member 204 of shifting mechanism 110b. It follows that to align central axes gap 502 substantially corresponds to gap 402.

It should be noted that in this embodiment, shifting mechanism 110 shifts conveyor belt 105 from a first position corresponding to that shown in FIG. 4 in which hollow cross member 201 is stopped by rear shaft collar 209 to a second position in which hollow tube is stopped and abuts against a forward shaft collar 208. However, by appropriate controlling of the pneumatic pressure, pneumatic cylinder 214 can be controlled to move mounting member 204 to any intervening position in accordance with Equation 1 from above to accommodate any diameter differential.

It should be noted, that movement of shifting mechanism 110 may be triggered in several ways. As a rule, although cartridges 104 come in a variety of sizes, they are processed in batches of the same size because packaging and shipment to stores is done as an order of a single size. Therefore, a switch on the filling system 103 can be set to the desired size to control hydraulic pneumatic cylinder 214 to adjust the placing of cartridge 104 to a position corresponding to the appropriate diameter. Cartridges are manufactured with their product number thereon; usually a machine-readable code such as barcode. The reading of the barcode which indicates the cartridge size can also trigger the control the movement of pneumatic cylinder 214. It should be noted, that the use of optical sensors or product readers in reality would allow adjustment of conveyor 105 on the fly in real time to accommodate the processing of mixed batches.

Accordingly, the shift depicted in FIG. 5 completes the spatial alignment of the entire range of cartridges 104, the shuttle mechanism 110 is appropriately shifted to reposition the cleated indexing conveyor 105 by amount 502 effectively relocating the cartridge axial center 401 to a position coincident with the axial center of all interfacing tooling and processing equipment.

Reference is now made to FIG. 6 which shows the shifting and aligning process from a top view to better exemplify the movement of conveyor belt 105 and push block 222. Again, like numerals are utilized to indicate like structure. As seen, in this view, a shifting mechanism 110a and all of the associated elements are shown side by side with a shifting mechanism 110b rather than one on top of the other as in FIG. 5. Again, cartridge 104a has a smaller outer diameter than cartridge 104b. Therefore, a conveyor belt 105a is shifted to relative to a conveyor belt 105b.

As can be seen, pneumatic cylinder 214 is activated so as to slide hollow shaft 201 along shaft 207 to be moved in a direction away from rear shaft collar 209. This shifts conveyor belt 105a in the direction of arrow A by a distance 602 corresponding to distance 402 and gaps 402 and 502 so that central axis 401 and 405, the respective cartridges 104a, 104b are the same distance from V-shaped block 222. As seen in FIG. 6, as compared to FIGS. 4, 5, pneumatic cylinder 221 has been added for firing V-shaped block 222 into contact with respective cylinders 104a, 104b to position the respective cylinders 104a, 104b in the proper upright orientation within the space created by cleats 107, conveyor belt 105, rail 240.

During operation, the geometry of the next batch of cartridges 104 to be filled is input to the machine in which filling system 103 resides. Conveyor belt 105 is shifted by shifting mechanism 110 to accommodate the shape of the cartridge. Cartridges are dropped onto conveyor 105 between successive cleats 107 and are substantially in an upright position, i.e., a central axis of cartridge 104 is relatively coaxial with the axis of the flow of material from a filling spout at a filling station. As cartridge 104 approaches the filling station, it reaches a position in which it is in facing relationship with alignment fixture 220 which performs finishing alignment by moving in a V-shaped block 222 in a direction to engage cartridge 104. Because the symmetrical nature of the arms of the V-shaped block 222 provide a camming service, no matter what the geometry (shape, diameter, or length) of cartridge 104, it will slide along block 222 until it abuts against both arms of the V-shaped block 222 and is held in a true upright position. Because of the adjustment of conveyor belt 105, the cleats 107 can be permanently affixed to conveyor 105 and maintained at a spaced relationship sufficient to prevent a cartridge of a desired range of outer diameters from being able to fall on its side (i.e., away from a substantially upright orientation). As a result, the belt need not be retooled between each change of cartridge geometry being processed.

Cartridges 104a and 104b are positioned against their respective cleated indexing conveyor 105a and 105b by the respective alignment fixtures. As depicted, the shuttle mechanism 110 is required to be shifted by amount 602 in an effort to align the axial centers 401 and 405 of cartridges 104a and 104b respectively.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures and functions of the relevant exemplary embodiments. Thus, the description of the invention is merely exemplary in nature and, thus, variations that do not depart from the spirit and scope of the invention are intended to be within the scope of the exemplary embodiments of the present invention. Such variations are not to be regarded as a departure from the spirit and scope of the present invention.

Claims

1. A filling system for filling cartridges having any one of a variety of outer diameters comprising:

a conveyor, the conveyor includes cleats extending therefrom at spaced intervals; and

a shifting mechanism coupled to said conveyor for shifting said conveyor between a first position and a second position, the distance between the first position and second position being a function of the outer diameter of a cartridge to be filled.

2. The filling system of claim 1, wherein said filling system includes a frame, a shaft affixed to said frame, a hollow shaft slidably mounted about said frame, a linear power transmissive assembly coupled to said hollow member, said conveyor being affixed to said hollow member, wherein activation of said linear power transmissive assembly moves said cylinder between a first position and a second position.

3. The filling system of claim 2, further comprising a rear shaft collar mounted on said shaft for defining said first position, and a forward shaft collar mounted on said shaft at a distance spaced from said rear shaft collar and defining said second position.

4. The filling system of claim 1, wherein said distance corresponds to one-half the difference of the outer diameter of a first cartridge minus the outer diameter of a second cartridge, the first cartridge having a greater outer diameter than the second cartridge.

5. The filling system of claim 1, further comprising an alignment mechanism in facing relationship with the conveyor.

6. The filling system of claim 5, wherein the alignment mechanism includes a pushing block for engaging said cartridge, said cartridge disposed between respective cleats and said pushing block aligning a central axis of the cartridge in an orientation for filling.

7. The filling system of claim 6, wherein said pushing block has opposed substantially symmetrical arms and moves moves between a first position away from said conveyor and a second position towards said conveyor and aligning a cartridge when in the second position.

8. A method for filling cartridges having any one of a variety of outer diameters comprising:

providing a conveyor, the conveyor having cleats extending therefrom at spaced intervals to define a space;

determining the size of the cartridge to be filled; and

shifting the conveyor between a first position and a second position as a function of the outer diameter of the cartridge.

9. The method of claim 8 comprising the step of aligning the cartridge in the space to be substantially coaxial with an axis of flow of material into the cartridge during a filling process.

10. The method of claim 9 further comprising the step of aligning said cartridge by pushing said cartridge toward said conveyor with a pushing block, the pushing block having opposed substantially symmetrical arms.