Molded Article Picker
Disclosed are a molded article picker for a post-mold device and a related method for the use of the molded article picker for handling a molded article. The molded article picker includes a floating element being configured to be movable between an extended position and a retracted position and biased in the extended position. Furthermore, the molded article picker comprises a pressure structure extending through the floating element. The floating element is cooperable with the molded article to define a substantially enclosed volume including the pressure structure. The pressure structure is configured such that by evacuating the substantially enclosed volume the molded article is sealed to the floating element and the floating element is drawn into the retracted position, thereby transferring the molded article to the molded article picker.
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The present invention generally relates to molded article pickers, and more specifically the present invention relates to, but is not limited to, a post-mold device including such a molded article picker, a molding system including the post-mold device, and a related method for the use of the molded article picker for handling a molded article.
BACKGROUND OF THE INVENTIONA lot of injection molded articles, for example plastic preforms of the variety that are for blow molding into beverage bottles, require extended cooling periods to solidify into substantially defect-free molded articles. To the extent that the cooling of the molded article can be effected outside of the injection mold by one or more so-called post-mold devices, the productivity of the injection mold may be increased (i.e. by reducing the cycle time). A variety of such post-mold devices, and related methods, are known and have proven effective in optimizing, i.e. reducing, the injection molding machine cycle time.
In a typical injection molding system a just-molded, and hence only partially cooled, molded article is ejected from the injection mold and into a post-mold device, commonly known as a take-out device or end-of-arm-tool (EOAT), having a plurality of cooled carriers (otherwise known as a cooling tube, take-out tube, cooling sleeve, amongst others) for post-mold cooling of the molded article outside of the mold.
U.S. Pat. No. Re. 33,237 describes a post-mold device for removing partially cooled injection molded preforms from the core side of an injection mold. The preforms are ejected from the mold directly into cooled carriers (such as that described in commonly assigned U.S. Pat. No. 4,729,732), and transported by the post-mold device to an outboard position adjacent the mold. The post-mold device may include multiple sets of carriers to accommodate multiple sets of preforms (i.e. multiple shots or batches of preforms).
Commonly assigned U.S. Pat. No. 6,171,541 describes another post-mold device that includes a set of cooling pins for insertion into the interior of a partially cooled preform, the preform arranged in a cooled carrier of a first post-mold device, to discharge a cooling fluid therein. An example of the foregoing is sold under the trade name of COOLJET, a trade-mark of Husky Injection Molding Systems Limited.
Commonly assigned U.S. Pat. No. 7,104,780 describes a post-mold device similar to that of the '541 patent further including molded article pickers for removal of the preform from the cooled carrier of the first post-mold device. The molded article picker includes a pin operable to cooperate with a vacuum source to evacuate a volume defined within the preform to cause the preform to remain therewith as the molded article picker is moved away from the carrier. The second post-mold device, mounted to a frame, may be rotated by 90 degrees to a discharge position and the vacuum to the molded article pickers may be terminated to allow the preforms to fall off the pins.
An example of the foregoing post-mold device is sold under the trade name of COOLPIK, a trade-mark of Husky Injection Molding Systems Limited. The molded article picker of the second post-mold device further includes a sealing surface disposed on a front face of a tooling plate to sealingly cooperate with a front face of the preform in response to the evacuation of the volume. According to this solution the preform is transferred over a small gap between the front face of the preform, arranged in the carrier of the first post-mold device, and the sealing surface of the molded article picker.
Although the above solution already constitutes a substantial improvement with respect to the prior art it has been found that in practice the transfer of the molded article from a carrier to the molded article picker sometimes fails. It is believed that this improper transfer is caused by an insufficient vacuum applied and the air flow resulting therefrom to transfer the molded article across the gap between the front face of the molded article and the sealing surface of the molded article picker. This occurs especially with molded articles having a shallow draft on the outside thereof. Consequently, it can happen that molded articles are not transferred properly, i.e. are left in the carrier, and, thus, block this carrier for the introduction of a molded article of the next shot of molded articles, which for obvious reasons is highly undesirable.
There is, thus, a need for a molded article picker providing for an improved reliability of transfer of a molded article from a carrier on a first post-mold device to such a molded article picker on a second post-mold device.
SUMMARY OF THE INVENTIONAccording to a first aspect of the present invention, there is provided a molded article picker for a post-mold device for transferring a molded article. The molded article picker includes a floating element being configured to be movable between an extended position and a retracted position and a pressure structure. The floating element is cooperable with the molded article to define a substantially enclosed volume including the pressure structure. The pressure structure is configured such that by evacuating the substantially enclosed volume the molded article is sealed to the floating element and the floating element is drawn into the retracted position, thereby transferring the molded article to the molded article picker.
According to a second aspect of the present invention, there is provided a post-mold device including a tooling plate and a molded article picker as described in the previous section arranged on the tooling plate.
According to a third aspect of the present invention, there is provided a molding system comprising a post-mold device, having a tooling plate and a molded article picker as described above arranged on the tooling plate for transferring a molded article.
According to a fourth aspect of the present invention, there is provided a method for transferring a molded article, comprising the steps of bringing a floating element of a molded article picker in an extended position, at least in part, into abutment with a surface of the molded article and evacuating the enclosed volume defined by the molded article and the floating element such that the molded article is sealed to the floating element and the floating element is drawn into a retracted position, thereby transferring the molded article.
A better understanding of the exemplary embodiments of the present invention (including alternatives and/or variations thereof) may be obtained with reference to the detailed description of the exemplary embodiments along with the following drawings, in which:
With reference to
The first post-mold device 13 is mounted on the stationary platen 16 and includes a beam 20 that projects to one side of the machine (e.g. the non-operator side) and upon which rides a carriage 21, moved along the beam by (typically) a servo-electric driven belt drive (not shown). A tooling plate 107 is attached to the carriage 21. Multiple sets of carriers 108, e.g. three sets in the exemplary embodiment, are mounted on plate 107 and may be cooled for transporting multiple molded shots of molded articles 109 (the ‘molded article’ also will be henceforth referred to as a ‘preform’ in keeping with the context of the exemplary embodiment) ejected from the mold from an inboard (loading) position (not shown).
The second post-mold device 14 includes a tooling plate 100 upon which are mounted multiple sets of cooling pins 112, two sets in the exemplary embodiment, and a set of molded article pickers 120 in accordance with the preferred embodiment. In
A rotatable mount 40, 45 attaches the tooling plate 100 to moving platen 41 for rotation through an arc. The rotation of the tooling plate 100 can be effected, for example, by an electric drive (not shown) mounted to the rotatable mount 40, 45.
In operation, a shot or batch of molded articles or preforms 109 are transferred into a set of empty carriers 108 when the mold is open and the tooling plate 107 is positioned such that the empty carriers 108 are aligned with molded articles on the core half 17. The tooling plate 107 is then moved to its outboard position by the carriage 21, as shown in
Meanwhile, as the mold closes, the tooling plate 100 of the second post-mold device 14 moves towards the molded article carriers 108, whereby the sets of cooling pins 112 are arranged within the interior of the corresponding preforms 109 that have been most recently molded, and the molded article pickers 120 are arranged to engage an end portion, and in particular the front face 110 (as shown in
As shown in
A preferred embodiment of a molded article picker 120 according to the present invention is depicted in
The molded article picker 120 according to the preferred embodiment of the present invention comprises a floating element 123 that is movably connected to and guided by a base element 140 which, in turn, is mounted to the tooling plate 100. The person skilled in the art, however, will appreciate that, alternatively, the base element 140 also could be an integral part of the tooling plate 100. As will be described in more detail further below the floating element 123 can be moved between an extended or forward position (shown in
The floating element 123 of the molded article picker 120 according to the preferred embodiment of the present invention is spring-biased in the extended position for receiving molded article 109 by means of at least one biasing and guiding assembly. Each biasing and guiding assembly comprises a compressible spring 126 that is coiled about a respective cylindrical guiding pin 128 depending from a radial flange 119 of the floating element 123. The cylindrical guiding pin 128 is slidably arranged and guided within a cylindrical guiding recess 130 formed in the base element 140 and the tooling plate 100. The preferred embodiment of the molded article picker 120 shown in
In addition to the above described biasing and guiding assemblies the motion of the floating element 123 of the molded article picker 120 according to the preferred embodiment between the extended or forward and the retracted or rear position is furthermore guided by a cylindrical lower guiding portion 125 of a pressure structure, preferably a vacuum pin 124, which is arranged within a cylindrical bore through the base element 140. The arrangement of the vacuum pin 124 within the cylindrical bore through the base element 140 should allow for a guided gliding movement of the vacuum pin 124 within the cylindrical bore and at the same time substantially prohibit the flow of fluid between the inner face of the cylindrical bore and the outer face of the guiding portion 125 of the vacuum pin 124, as will be outlined in more detail below.
When no external forces are applied to the floating element 123 of the molded article picker 120 according to the preferred embodiment, due to the tendency of the at least one compressible spring 126 to relax itself from being compressed the floating element 123 will be spring-biased in the extended or forward position, as shown in
The molded article picker 120 comprises furthermore a compliable sealing element 122 disposed on the upper face of the radial flange 119 of the floating element 123. Preferably, the sealing element 122 is made from a silicone rubber and is bonded to the radial flange 119 and adjacent portions of the floating element 123 in proximity thereto, as shown in
In operation, when the tooling plate 100 of the second post-mold device 14 approaches the tooling plate 107 of the first post-mold device 13, during mold closing, the molded article picker 120 engages the molded article 109 by bringing the front face 110 of the molded article 109 in close contact and preferably into abutment with the upper face of the sealing element 122 on the upper face of the radial flange of the floating element 123. As it is made of a compliant material, preferably silicone rubber, upon contact with the front face 110 of the molded article 109 the sealing element 122 will be deformed and compressed. However, due to the force exerted upon the radial flange 119 of the floating element 123 by the at least one compressed spring 126 as well as the tendency of the deformed sealing element 122 to restore its original shape, a fluid-tight seal will be formed between the front face 110 of the molded article 109 and the sealing element 122 disposed on upper face of the radial flange 119 of the floating element 123 of the molded article picker 120 according to the preferred embodiment of the present invention. Thereafter, a pressure channel 138 formed between the lower face of the tooling plate 100 and a backing plate 134 affixed thereto and in fluid communication with the interior of the vacuum pin 124 is connected via a manifold (not shown) to a pressure source and the enclosed volume V1 defined by the interior of the molded article 109 and the interior of the vacuum pin 124 is evacuated via the pressure channel 138. As the enclosed volume V1 defined by the interior of the molded article 109 and the interior of the vacuum pin 124 is essentially sealed from the environment, the floating element 123 is withdrawn by the vacuum force into the retracted or rear position shown in
For preform 109 shown in the exemplary embodiment the floating element 123 is displaced by a distance of about 7 mm from its retracted or rear position to its extended or forward position, e.g. after the vacuum has been turned off and the preforms 109 have been dropped onto a conveyor. Preferably, the equilibration between the abutment of the front face 110 of a preform 109 of a subsequent batch and the sealing element 122 and the force exerted by the at least one spring 126 causes the floating element 123 to be displaced by about 2 mm in the direction of the retracted or rear position. Out of this position the floating element 123 and the molded article 109 sealed thereto are moved into the retracted or rear position over a distance of about 5 mm by applying a vacuum to the enclosed volume V1 defined by the interior of the molded article 109 and the vacuum pin 124 via the pressure channel 138.
As can be taken from
With reference to
The molded article picker 220 includes a floating element 223 that is biased by a spring 226 to the extended or forward position, as shown in
As can be taken from
In operation, the second post mold device 14 is translated to cause the molded article picker 220 to engage the molded article 209, as explained previously with respect to the first exemplary embodiment, such that the front face 210 of the molded article 209 is arranged in close proximity, preferably in abutment, with the sealing face 222 of the floating element 223. Thereafter, the pressure channel 238 is connected to a pressure source and an enclosed volume V1′ (
The description of the exemplary embodiments provides examples of the present invention, and these examples do not limit the scope of the present invention. It is understood that the scope of the present invention only is limited by the claims. The inventive concepts described above may be adapted for specific conditions and/or functions, and may be further extended to a variety of other applications that are within the scope of the present invention. For instance, it might well be the case that for molded articles having a shape different to the one of a preform a pressure structure other than a vacuum pin might be better suited to perform the function of the present invention, i.e. to seal the molded article to the floating element and to withdraw the floating element into its retracted position. Having thus described the exemplary embodiments, it will be apparent that modifications and enhancements are possible without departing from the concepts as described. Therefore, what is to be protected by way of letters patent are limited only by the scope of the following claims.
Claims
1. A molded article picker for transferring a molded article, the molded article picker comprising:
- a floating element, the floating element configured to be movable between an extended position and a retracted position; and
- a pressure structure;
- wherein the floating element is cooperable with the molded article to define a substantially enclosed volume including the pressure structure, at least in part;
- wherein the pressure structure is configured such that by evacuating the substantially enclosed volume the molded article is sealed to the floating element and the floating element is drawn into the retracted position, thereby transferring the molded article to the molded article picker.
2. The molded article picker of claim 1, wherein the pressure structure comprises a vacuum pin extending through the floating element.
3. The molded article picker of claim 2, wherein the vacuum pin is integrally formed with the floating element.
4. The molded article picker of claim 1, wherein the floating element includes a radial flange.
5. The molded article picker of claim 1, further comprising a compliable sealing element disposed on a surface of the floating element, the sealing element configured to form a seal with the molded article.
6. The molded article picker of claim 1, further comprising at least one compressible spring for biasing the floating element in the extended position.
7. The molded article picker of claim 6, wherein the floating member includes a guiding pin for receiving the spring, and wherein the guiding pin is slidably received within a guiding recess disposed, at least in part, in a base element.
8. The molded article picker of claim 6, wherein the floating member includes a spring seat for receiving the spring, and wherein the floating member includes a guide portion slidably arranged on the pressure structure provided by a vacuum pin.
9. The molded article picker of claim 4, further comprising a cylinder element and wherein the enclosed volume is formed between, at least in part, a surface of the cylinder element, a member the radial flange.
10. The molded article picker of claim 1, wherein the pressure structure further comprises an actuator pressure channel in fluid communication with the enclosed volume.
11. The molded article picker of claim 2, wherein the pressure structure further comprises an actuator pressure channel provided through the vacuum pin, the actuator pressure channel in fluid communication with the enclosed volume.
12. A post-mold device, comprising:
- a tooling plate; and
- a molded article picker arranged on the tooling plate for transferring a molded article, the molded article picker comprising: a floating element, the floating element configured to be movable between an extended position and a retracted position; and a pressure structure; wherein the floating element is cooperable with the molded article to define a substantially enclosed volume including the pressure structure, at least in part, wherein the pressure structure is configured such that by evacuating the substantially enclosed volume the molded article is sealed to the floating element and the floating element is drawn into the retracted position, thereby transferring the molded article to the molded article picker.
13. The post-mold device of claim 12, wherein the pressure structure comprises a vacuum pin extending through the floating element.
14. The post-mold device of claim 13, wherein the vacuum pin is integrally formed with the floating element.
15. The post-mold device of claim 12, wherein the floating element includes a radial flange.
16. The post-mold device of claim 12, wherein the molded article picker further comprises a compliable sealing element disposed on a surface of the floating element, the sealing element configured to form a seal with the molded article.
17. The post-mold device of claim 12, wherein the floating element further comprises at least one compressible spring for biasing the floating element in the extended position.
18. The post-mold device of claim 17, wherein the floating member includes a guiding pin for receiving the spring, and wherein the guiding pin is slidably received within a guiding recess disposed, at least in part, in a base element.
19. The post-mold device of claim 17, wherein the floating member includes a spring seat for receiving the spring, and wherein the floating member includes a guide portion slidably arranged on the pressure structure provided by a vacuum pin.
20. The post-mold device of claim 15, wherein the molded article picker further comprises a cylinder element and wherein the enclosed volume is formed between, at least in part, a surface of the cylinder element, a member the radial flange.
21. The post-mold device of claim 12, wherein the pressure structure further comprises an actuator pressure channel in fluid communication with the enclosed volume.
22. The post-mold device of claim 13, wherein the pressure structure further comprises an actuator pressure channel provided through the vacuum pin, the actuator pressure channel in fluid communication with the enclosed volume.
23. A molding system, comprising:
- a mold;
- a post-mold device, having: a tooling plate; and a molded article picker arranged on the tooling plate for transferring a molded article, the molded article picker comprising: a floating element, the floating element configured to be movable between an extended position and a retracted position; and a pressure structure; wherein the floating element is cooperable with the molded article to define a substantially enclosed volume including the pressure structure, at least in part, wherein the pressure structure is configured such that by evacuating the substantially enclosed volume the molded article is sealed to the floating element and the floating element is drawn into the retracted position, thereby transferring the molded article to the molded article picker.
24. The molding system of claim 23, wherein the pressure structure comprises a vacuum pin extending through the floating element.
25. The molding system of claim 24, wherein the vacuum pin is integrally formed with the floating element.
26. The molding system of claim 23, wherein the floating element includes a radial flange.
27. The molding system of claim 23, wherein the molded article picker further comprises a compliable sealing element disposed on a surface of the floating element, the sealing element configured to form a seal with the molded article.
28. The molding system of claim 23, wherein the floating element further comprises at least one compressible spring for biasing the floating element in the extended position.
29. The molding system of claim 28, wherein the floating member includes a guiding pin for receiving the spring, and wherein the guiding pin is slidably received within a guiding recess disposed, at least in part, in a base element.
30. The molding system of claim 28, wherein the floating member includes a spring seat for receiving the spring, and wherein the floating member includes a guide portion slidably arranged on the pressure structure provided by a vacuum pin.
31. The molding system of claim 26, wherein the molded article picker further comprises a cylinder element and wherein the enclosed volume is formed between, at least in part, a surface of the cylinder element, a member the radial flange.
32. The molding system of claim 23, wherein the pressure structure further comprises an actuator pressure channel in fluid communication with the enclosed volume.
33. The molding system of claim 24, wherein the pressure structure further comprises an actuator pressure channel provided through the vacuum pin, the actuator pressure channel in fluid communication with the enclosed volume.
34. The molding system of claim 23, wherein the mold includes a stack assembly defining a mold cavity, and wherein the stacks are replaceable by conversion.
35. The molding system of claim 23, wherein the molded article picker are configured to be replaced by conversion.
36. The molding system of claim 23, wherein the mold includes a stack assembly defining a mold cavity, and wherein the stacks are replaceable by refurbishment.
37. The molding system of claim 23, wherein the molded article picker are configured to be replaced by refurbishment.
38. A floating element of the molded article picker in accordance with any one of claims 1 to 11.
39. A method for transferring a molded article, comprising:
- bringing a floating element of a molded article picker in an extended position, at least in part, into abutment with a surface of the molded article; and
- evacuating an enclosed volume defined by the molded article and the floating element through a pressure structure of the molded article picker such that the molded article is sealed to the floating element and the floating element is drawn into a retracted position, thereby transferring the molded article.
Type: Application
Filed: Jan 10, 2007
Publication Date: Jul 10, 2008
Applicant: HUSKY INJECTION MOLDING SYSTEMS LTD. (Bolton)
Inventors: Rainer Kintzinger (Merzig), Derek Robertson McCready (Mississauga), Luc Rommes (Eischen)
Application Number: 11/621,639
International Classification: H01L 21/677 (20060101); B29C 45/43 (20060101); B29C 33/46 (20060101);