TAKE OUT AND COOLING SYSTEM AND METHOD
A take-out and cooling method and apparatus conveys molded plastic articles from a molding machine to and through a cooling station and preferably includes a take-out apparatus that has a main support, a conveyor carried by the main support for movement in an endless path, a cam adjacent to the support, a plurality of arms carried by the conveyor for movement with the conveyor along the endless path and including a follower responsive to the contour of the cam to vary the position of the arms relative to the support, and at least one holder carried by each arm. Each holder is adapted to receive and carry at least one molded article to facilitate in conveying the molded articles and is flexible and resilient to permit relative movement of at least a portion of the holder relative to its associated arm.
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This invention relates generally to molding plastic articles, and more particularly to an apparatus and a method for conveying molded articles from a molding machine to and through a cooling station.
BACKGROUND OF THE INVENTIONPlastic articles, such as preforms for plastic containers, can be formed by various methods including injection molding and compression molding. The molded preforms are subsequently processed, such as by blow molding, into their desired final shape. After the initial molding step, the preforms are preferably promptly removed from the mold tooling in a still somewhat soft and pliable condition, to increase the efficiency and production rate of preforms for each mold. It may be desirably to initially cool the preforms prior to their being formed in a blow molding apparatus to facilitate handling the preforms, and to control the cooling of the preforms and thereby control the physical properties of the preforms prior to being blow molded. Accordingly, challenges are presented in removing the at least somewhat soft preforms from the molding machine and transferring them to a cooling machine at a desired rate and without damaging the preforms. Challenges are also presented in efficiently and effectively cooling the preforms at a desired rate and without damaging the preforms as they are moved through the cooling station.
SUMMARY OF THE INVENTIONA take-out and cooling method and apparatus, in accordance with an exemplary but presently preferred first aspect of the invention, conveys molded plastic articles from a molding machine to and through a cooling station. The apparatus preferably includes a take-out apparatus that has a main support, a conveyor carried by the main support for movement in an endless path, a cam adjacent to the support, a plurality of arms carried by the conveyor for movement with the conveyor along the endless path and including a follower responsive to the contour of the cam to vary the position of the arms relative to the support, and at least one holder carried by each arm. Each holder is adapted to receive and carry at least one molded article to facilitate in conveying the molded articles and is flexible and resilient to permit relative movement of at least a portion of the holder relative to its associated arm.
In accordance with another exemplary but presently preferred aspect of the invention, a molded article cooling system includes a transfer mechanism that receives a plurality of molded articles and conveys them along a path from an infeed section to an outfeed section, and a cooling mechanism extending along the path and having an elongate fluid outlet through which fluid is directed toward the plurality of molded articles. The fluid outlet is substantially continuous along at least a portion of the path so that a substantially continuous stream of fluid is directed toward said plastic articles. The fluid outlet is preferably defined by at least two plates that are adjustable to permit the width and/or direction of the fluid stream discharged from the fluid outlet to be adjusted as desired. Desirably, the fluid outlet provides a generally continuous line or knife of coolant flow rather than intermittent streams of fluid flow such as from a plurality of spaced nozzles.
Accordingly to yet another presently preferred embodiment, a system for removing molded articles from a molding machine and cooling the molded articles includes a take-out mechanism that receives molded articles from the molding machine and conveys them away from the molding machine, an intermediate conveyor that conveys molded articles away from the take-out apparatus to a cooling station, and a cooling conveyor that conveys the molded articles from the intermediate conveyor through the cooling station. The cooling conveyor preferably includes at least one pair of spaced apart belts adapted to frictionally engage and carry the molded plastic articles from an infeed section of the cooling conveyor to an outfeed section of the cooling conveyor. Preferably, the cooling conveyor advances molded articles at a slower rate than does the intermediate conveyor to reduce the spacing between adjacent molded articles. Also preferably, the intermediate conveyor preferably includes a permeable belt to communicate with a vacuum source and adapted to engage an upper end of molded articles to suspend the molded articles from the permeable belt under the vacuum force.
These and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and best mode, appended claims and accompanying drawings in which:
Referring in more detail to the drawings,
In one presently preferred embodiment, the molding machine 18 forms plastic preforms 12 that are subsequently blow molded into a desired final shape, such as to form plastic containers. The molding machine 18 may include a plurality of pairs of mold tooling 20 including an upper mold tooling half 28 and a lower mold tooling half 30 (
In more detail, as shown in
The drive assembly 42 (
Each arm 32 preferably includes a block 80 slidably carried on at least one and preferably a pair of slide rods 82 to permit axial, or vertical (as viewed in
In the presently preferred embodiment, wherein the molding machine 18 includes a rotary turret 95 (
As best shown in
Each finger 104 is preferably flexible and resilient to limit the force applied to a molded article 12 if, for example, the molded article 12 is offset or misaligned slightly from the receptacle 108. The flexible fingers 104 also prevent damage to the arms 32 should they encounter interference, and may be constructed and arranged to break away at a force low enough to prevent damage to the associated arm 32 in such a situation. In one presently preferred embodiment, the fingers 104 are composed of coil springs having a stiffness chosen to adequately support and retain the molded articles 12 without applying undesirable pressure to the molded articles 12 through the contact members 110.
In addition to the fingers 104, each receptacle 108 is preferably also defined at least in part by a flexible support 114 carried by the carrier plate 102. The flexible supports 114 are arranged to support a lower surface of the molded articles 12 and may be formed relatively inexpensively from spring steel. The flexible supports 114 for both receptacles 108 defined on each arm 32 can be formed from a single spring member attached to the carrier plate 102 between its ends, with each end being cantilevered so that it is flexible, resilient and extends into a corresponding receptacle 108.
Desirably, the receptacles 108 of each holder 100 are aligned with a mold core 116 (
As best shown in
As best shown in
As shown in
Each of the pair of side conveyors 148 preferably includes a belt 158 wrapped around at least a pair of pulleys 160 with one pulley 160 at an infeed section 164 of the cooling station 26 and the other pulley (not shown) at the outfeed section 166 of the cooling station 26. If desired, multiple pulleys may be provided between the infeed section 164 and outfeed section 166 providing additional support for the belt 158. Each side conveyor belt 158 is adapted to engage a sidewall 168 of the molded articles 12 so that the molded articles 12 are supported in an upright position as they are carried through the cooling station 26 by the side conveyors 148 and lower conveyor 146. Each belt 158 may be wrapped partially about a guide pulley 170 and around a driven pulley 172 fixed to the shaft 154 and driven by the motor 156 so that each belt 158 of the side conveyors 148 and the belt 150 of the lower conveyor 146 are driven by the same shaft 154 and motor 156. As best shown in
As best shown in
As best shown in
In
The upper and lower plenums 208, 210 may be similarly constructed to define an elongate, preferably continuous enclosure in which coolant is received. Each plenum 208, 210 is defined at least in part by one or more fluid outlet plates 212 that define an elongate and preferably at least substantially continuous fluid outlet 214 through which coolant is discharged from each plenum 208 and toward molded articles 12 being conveyed through the cooling station 200. In one presently preferred embodiment, each elongate fluid outlet 214 is defined by a pair of elongate plates 212 fixed to the associated plenum 208, 210 with a linear slot between the plates 212 defining the fluid outlet 214. Preferably, the plates 212 include outwardly extending flanges 216 which may be adjustably carried or connected to an associated plenum 208, 210 to permit the size and location of the fluid outlet 214, relative to molded articles 12 conveyed through the cooling station 200, to be changed. The plates 212 may include slots 215 (
In one presently preferred embodiment, the plates 212 are generally L-shaped in section and include flanges 218 extending into an associated plenum 208, 210 and defining a passage 220 communicating with the fluid outlet 214 through which coolant flows from the plenum 208, 210 to the fluid outlet 214. In the presently preferred embodiment, the fluid outlet 214 is continuous and extends without interruption from a location generally adjacent to the infeed section 222 of the cooling station 200 to the outfeed section 224 of the cooling station 200. Accordingly, rather than discreet or individual coolant nozzles, in this embodiment, a continuous and preferably generally linear stream, curtain or knife of coolant is provided onto the molded articles 12 as they are conveyed through the cooling station 200.
To convey the molded articles 12 through the cooling station 200, two spaced cooling conveyors 202 are provided. As best shown in
In one presently preferred embodiment, the cooling station 200 is employed to cool molded plastic preforms 12 including a generally cylindrical finish 250 preferably having a plurality of external threads 252, and a radially outwardly extending flange 254 between the finish 250 and a main body 256 of the preform. In the preferred embodiment, the belts 230 are arranged to frictionally engage the threads 252 on the finish 250 of each preform at a location axially spaced from the flange 254. When carried and conveyed in this manner, the open upper end 258 of the preforms 12 are exposed to the fluid outlets 214 of an associated upper plenum 208 and the lower portion of the preforms, shown here as a closed semi-spherical end 260, are exposed to the elongate fluid outlet 214 of an associated lower plenum 210.
Accordingly, a stream of coolant is directed into the open upper ends 258 of each preform 12, and against the closed lower end 260 of each preform 12. The stream of coolant directed against the lower end 260 of the preforms 12 preferably flows upwardly and around a side wall 168 of the preforms 12 improving the cooling performance. Because the plates 242 defining the fluid outlets 214 are adjustable relative to the plenums 208, 210 the location of the fluid outlets 214 relative to an axis 270 of the preforms 12 can be adjusted. The streams of coolant discharged from the fluid outlets 214 can be arranged to be coincident with a plane including the axis 270 of each preform 12 along the cooling conveyor 202. The fluid outlets 214 can also be moved so that the streams are parallel but spaced from the plane containing the axis 270 of each preform 12. And the plates 242 can be adjusted so that the direction of the streams is not parallel to the plane containing the axes 270 of the preforms. In that arrangement, the stream may intersect the plane containing the axes 270 of the preforms 12, or may be entirely separate from that plane, at least from the fluid outlet 214 to the upper end 258 of the preforms 12.
The fluid outlet 214 of the upper plenum 208 is preferably offset from the plane containing the axes 270 of the preforms to provide a more turbulent flow within the preforms and improved flow into and out the preforms avoiding a stagnant section or layer of coolant in the interior of the preforms 12 to improve fluid flow and more evenly cool the preforms 12. The upper plenum 208 may be formed in two sections, and each section of the upper plenum 208 may be separately adjusted so that they direct coolant onto or into the preforms 12 at different locations or in generally different directions. This may provide more even cooling of the preforms 12.
Also preferably, the fluid outlet 214 of the lower plenum 210 is directed along or coincident with the plane containing the axes 270 of the preforms 12 so that the coolant engages the lower end 260 of the preforms 12 and flows generally evenly around the exterior of the preforms to improve the cooling properties thereof. Of course, the width of both the upper and lower fluid outlets 214 can be adjusted as desired, for example by moving the plates 212 further apart from each other.
In one presently preferred embodiment, the coolant is chilled forced air. The air may be passed through a heat exchanger to cool it, and then moved by one or more blowers through the fluid conduits 204, 206 and into the upper and lower plenums 208, 210. The temperature of the chilled air can vary widely, and in one presently preferred embodiment may be between 30° and 80° F., preferably around 40° to 60° F. The flow rate of coolant provided through the fluid outlets 214 can also be changed as desired as a function of the flow area of the fluid outlet 214, as well as the flow rate of fluid delivered to the plenums 208, 210. Other coolants may be used, including by way of example without limitation, compressed air and/or liquid coolants, such as water. Additionally, the cooling conveyors 202 may convey the preforms 12 through a coolant bath such as by passing the preforms 12 through a pool or bath of water or other coolant.
Preferably, the cooling conveyors 202 are driven at a rate that is slower than the rate at which the intermediate conveyor 120 is driven to reduce the pitch or spacing between adjacent preforms 12 and thereby increasing the time that the preforms 12 spend in the cooling station 26, 200. This increases the efficiency of the cooling station 26, 200 by increasing the potential cooling available per length of cooling station 26, 200 and also reduces the required floor space for the apparatus.
An alternate embodiment holder assembly 300 for the take-out apparatus 24 is shown in
In the embodiment shown, each holder 300 includes four upstanding, flexible and resilient fingers 306 and a pair of axially spaced contact members 308. Each contact member 308 is preferably annular, and is fixed to the fingers 306 so that openings 312 of associated contact members 308 are coaxially aligned. To facilitate alignment of a molded article 12 with a receptacle 310, the openings 312 through the contact members 308 preferably have an entrance portion 314 that is beveled or tapered. The flexible and resilient fingers 306 can be formed from appropriate springs, as set forth with regard to previous embodiment. The springs or other finger arrangement are preferably received through circumferentially spaced bores 315 in the contact members 308. The contact members 308 can be retained on the fingers 306 by set screws 316 disposed in radial 318 bores in the contact members 308 and extending into engagement with the fingers 306. Desirably, the annular contact members 308 are generally thin in the axial direction to limit the surface area or contact area of the contact members 308 with the molded plastic articles 12. Any number and arrangement of contact members 308, or no contact members, may be provided for each holder 300, as desired.
In use, the molding machine 18 produces a plurality of molded articles 12, such as molded plastic preforms 12 that are subsequently processed or formed into plastic containers. The mold tooling 20 may include a female mold cavity and a male mold core 116 removably disposed in the mold cavity to form a preform 12. When the mold tooling halves 28, 30 are separated after a compression molding cycle, the preforms 12 are preferably carried by the mold cores 116 so that they are removed from the mold cavities when the mold tooling halves 28, 30 are separated.
During this time, an arm 32 of the take-out apparatus 24 is disposed beneath a pair of aligned mold cores 116 so that when the preforms 12 are released from the mold cores 116 the preforms 12 are disposed in the receptacles 108, 310 of the holders 100, 300 on the arm 32. The arm 32 continues to be driven about the periphery of the support plate 50 to carry the molded preforms 12 away from the molding machine and toward the intermediate conveyor 120. In the area of the infeed section 122 of the intermediate conveyor 120, the arms 32 are arranged so that the upper end of each preform 12 is generally aligned with an associated belt 130 of the intermediate conveyor 120. Desirably, the upper end of each preform 12 is brought into engagement with its associated belt 130 as the take-out arms 32 are driven relative to the intermediate conveyor 120. To prevent excessive force from being applied to the preforms 12 as they are brought into engagement with the belts 130, the flexible supports 114, 304 in the receptacle 108 are designed to flex to limit or prevent damage to the preforms under this load. The preforms are then held on the vacuum belt 130 under vacuum force, and the take-out arms 32 can be lowered away from the intermediate conveyor 120 as controlled by engagement of the cam followers 84 with the cam track 76 of the take-out apparatus 24.
The preforms 12 continue along the intermediate conveyor 120 until they reach the outfeed section 124 whereupon they are transferred to the cooling conveyors 146, 148, 202 of the cooling station 26, 200. Preforms 12 are carried by the belts 150, 158, 230 of the cooling conveyors 146, 148, 202 through the cooling station 26, 200 wherein one or more streams of coolant are directed at and into the preforms 12 to cool them. Hence, the preforms 12 are moved to and through the cooling station in-line with a plurality of preforms 12 being simultaneously cooled as they are moved through the cooling station. The preforms 12 are at least substantially continuously cooled as they are moved in-line through the cooling station, and are preferably continuously cooled by a continuous stream of fluid directed at the preforms as they are moved along at least a portion of the cooling path or cooling station. As noted herein, a plurality of lines of preforms may be formed for increased production rate and efficiency. While the terms “in-line” and “lines” have been used to describe the consecutive travel of the preforms 12, it is to be understood that the preforms do not have to travel linearly. Curved lines or other configurations can be employed.
While certain preferred embodiments and constructions and arrangements of particular components of the takeout and cooling system and method have been shown and described herein, one of ordinary skill in this art will readily understand that modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Further, relative adjectives like “upper,” “lower,” “central,” and the like are used to describe features of system, apparatus and method with respect to the position and orientation of such features as shown in the accompanying drawings of the presently preferred embodiments.
Claims
1-34. (canceled)
35. A molded article cooling system, including:
- a transfer mechanism that receives a plurality of molded articles and conveys them along a path from an infeed section to an outfeed section;
- a cooling mechanism extending along said path and having an elongate fluid outlet through which fluid is directed toward said plurality of molded articles, the fluid outlet being substantially continuous along at least a portion of said path so that a substantially continuous stream of fluid is directed toward said molded articles.
36-61. (canceled)
62. A system for removing molded articles from a molding machine and cooling the molded articles, the system including:
- a takeout apparatus having a plurality of arms adapted to receive molded articles from the molding machine and to convey molded articles from the molding machine, the arms being driven in an endless path to transfer molded articles from the molding machine;
- an intermediate conveyor having an infeed section adjacent to at least a portion of the takeout apparatus to receive molded articles from the takeout apparatus and convey molded articles away from the takeout apparatus and an outfeed section from which molded articles leave the intermediate conveyor;
- a cooling station through which the molded articles pass and including at least one fluid outlet through which a fluid is directed toward the molded articles to cool them; and
- a cooling conveyor having an infeed section adjacent to the outfeed section of the intermediate conveyor to receive molded articles from the intermediate conveyor and an outfeed section from which molded articles are removed from the cooling station.
63-78. (canceled)
79. A method of cooling a molded article, including the steps of:
- (a) conveying molded articles along a path; and
- (b) directing an elongate stream of coolant onto the molded articles as they are conveyed along said path, the elongate stream being continuous along at least a major portion of said path.
80-108. (canceled)
Type: Application
Filed: Dec 14, 2009
Publication Date: Jul 29, 2010
Applicant: Graham Packaging PET Technologies, Inc. (York, PA)
Inventors: Peter A. Bates (Perrysburg, OH), Thomas M. Ingraham (Fort Collis, CO), Frank W. Mahr (Toledo, OH), Nikhil Mani (Billerica, MA), Thomas E. Nahill (Amherst, NH), Terry C. Potter (Lambertville, MI)
Application Number: 12/637,086
International Classification: B29C 71/00 (20060101); B29C 49/64 (20060101); B29C 49/70 (20060101);