APPARATUS AND METHOD FOR REMOVING MOLDED ARTICLES IN UNIFORM ORIENTATION

Abstract: Method and apparatus for continuously receiving and collecting molded articles from a continuously cycling injection-moulding machine, whereby the articles are collected sequentially and continuously in a uniform physical position or orientation. The molded articles (28) are retained on receiving members (12, 13, 14, 16) by means of devices (32) connected to a vacuum source. The receiving members (12, 13, 14, 16) with the molded articles are moved away from the mold cavities (31) to release positions, whereby the articles (28) are free to drop by gravity in chutes (53) in the same orientation relative to the orientation of every other article.

Description: The present invention relates to injection molding and relates in particular to methods and machinery for recovering and collecting molded articles in continuous fashion. In modern high speed mass production of molded articles, it is important to maintain rapid molding cycles at uniform rates to maintain product quality. It is also desirable to recover molded articles quickly with a minimum interference with the mold cycle and without prolonging the cycle time. In the interest of efficient and economical packaging of the molded articles, it is desirable to receive, recover and collect articles continuously where the disposition of each article or its orientation is uniform. Articles so received and so arranged lend themselves to high speed automatic packaging machinery and similar processes. In contrast, where the articles are received or recovered in random fashion, it is frequently necessary to expend a great amount of manual effort to arrange the molded articles into a uniform, orderly orientation before introduction to a packaging station or to other processing operations. Prior art devices and methods have succeeded in solving this problem but frequently at the expense of prolonging the molding cycle. In addition, such prior art devices are manufactured of close tolerance piece parts which require considerable maintenance and frequent parts' replacement, because the said devices must be accurately positioned to receive molded articles upon ejection. A prior art apparatus of this case operable to recover molded articles with uniform orientation in continuous fashion is shown and described in US-A-3,910,740. In that patent and in the embodiment of Figs. 1.5, a pair of generally parallel rods 22a and 22b are traversed toward and away from a mold cavity in synchronism with the opening and closing of the mold cavity driven by the cam and follower arrangement shown in Fig. 5. When the mold cavity is closed the parallel rods are expanded and are disposed in the position of Fig. 2. Upon opening the mold the elements 22a and 22b are drawn to the edge of the molded article 21 providing a track for guiding the articles downwardly along a vertical path to a convenient receptacle. In usual and customary fashion, the molded articles are removed from the mold wall 19 by the stripper plate 16. In the US-A-3,910.740 mold time is lost while the articles are provided an interval of time to drop vertically by gravity. In addition, frequently the articles hang up in the track and must be advanced or urged along with a jet of air. In the US-A-3.767,342 a transfer apparatus is shown which includes a carriage which is mounted on a pair of support rails fixedly supported upon a frame and extending horizontally above the platens of the injection molding machine in a direction parallel to the direction of movement of the movable platen. The carriage is normally locked by structure including a pneumatic motor to movable platen for movement back and forth with the platen. A vertical rack assembly is mounted upon the carriage for vertical reciprocation between carriage side frame members. The rack assembly includes a pair of vertical rack members. At their lower ends, rack members are interconnected by a cup holder frame which supports four part holding cups. When locked the mold platen movement of platen drives the carriage thereby driving the rack assembly upwardly on closing movement of the platen and downwardly during opening movement of the platens. When the platens are in their fully opened position the holding cups are located in adjacent axial alignment with the freshly produced parts. When the platens are in their closed position, the cups have been elevated and moved to a position, at which the cups are adjacent opposed alignment with a pair of transfer chutes. The transfer chutes are formed with receiving openings through which the parts may be transferred into the interior of chutes. Therefore it is necessary that the alignment of the cups with the openings is very exact although the stroke of the injection molding machine and especially the end positions of the platens after each stroke are not the same in each case. The GB-A-1,172,827 shows a molding machine with a take-off-plate carried by the movable platen. As the movable platen approaches its outermost position the take-off-plate swings down in front of this mold portion and follows the core carrying the molded article. A collar on the take-off-plate intercepts the molded article as it is dislodged from the core. During the closing stroke of the machine the take-off-plate is elevated out of the path of the movable platen into a position above the fixed platen. Now a stationary abutment comes into contact with the molded article and knocks it out of its collar. Before this occurs a transfer member has come in behind the take-off-plate in line with the collar so as to receive the article therefrom. This transfer member engages the article and carries it along a partly linear and partly rotary path from the abutment into the open end of a stacking tube. This arrangement has the disadvantage that the molded article is transferred twice to two different transfer means between the way from the core to the stacking tube. In case the transfer at one transfer station is not quite correct the following transfer cannot be performed. The object of the present invention is to provide a relatively inexpensive simplified apparatus for collecting molded articles in a predetermined orientation in continuous fashion. The solution of this object is characterized by moving the receiving station during the separating of the platens away from the mold cavity free of the mold platens to said release station which are arranged in proximity of the mold elements on the same platen and releasing the molded article from said receiving station at the said release station whereby the article is free to drop by gravity to a station for further processing. This invention contemplates a simplified receiving member which is movable to and fro in synchronism with the molding cycle with a minimum of interference with the molding cycle. The movement of the receiving device depends on the stroke of the machine and the approach to the release station is always equal in case the receiving device and the release station are arranged on the same platen. A further advantage of the invention is the provision of an article receiving device which is free of the need for close tolerance piece parts and accurate positioning thereof to receive molded articles. A still further advantage of the invention is the provision of a novel method of removing, receiving and collecting molded articles in continuous fashion where all articles are gathered in the same physical arrangement or orientation. An apparatus for continuously collecting molded articles from a continuously operating injection molding machine embracing certain principles of the present invention comprises a pair of relatively movable mold platens, each platen supporting mold elements cooperating with mold cavities, said platens cycling continuously through a cavity opening stroke and a cavity closing stroke, a device for receiving and dispensing molded articles in a uniform physical orientation comprising a receiving device carried by one of said platens, said receiving device being movable from a first position defining a release position defining a receiving position near a release station to a second position defining a receiving position in proximity to a molded article retained on one of said platens, and transfer means carried by one of said platens responsive to relative motion between said platens for driving said receiving device from said first position to said second position, and is characterized in that the release station is also arranged on said platen which carries the receiving device. Other features and advantages of the present invention will become more apparent from an examination of the succeeding specification when read in conjunction with the appended drawings in which: Fig. 1 is a plan view of a stack or tiered injection molding set with a pair of fixed platens back-to-back and showing the mold cavities in the open condition; Fig. 2 is a view similar to Fig. 1 showing the mold cavities in the closed position; Fig. 3 is a perspective view of a portion of the article receiving device; Fig. 4 is a view similar to Fig. 3 showing the receiving device in register with the chute; Fig. 5 shows the receiving device in register with the chute and cover plate; Fig. 6 is a perspective view of the mechanism for driving the receiving devices; and Fig. 7 is a view similar to Fig. 6 illustrating the back side of the driving mechanism. In Figs. 1 and 2 the reference numeral 11 designates the top tier of a two-tier or stack mold set. Fig. 1 shows the open condition and Fig. 2 shows the closed condition. The arrangement is shown schematically and certain top portions are removed to facilitate explaining the principles of the invention. In some cases only one structure of a pair of structures will be described in detail with the understanding that one structure is identical to the other or is in opposite hand or mirror image thereof. For example, the mold set 11 is one set of a stack or two-tier set, i.e. one set 11 is positioned directly above the other. (Only the top mold set is shown in Figs. 1 and 2). Further, the reference numerals 12 and 13 and 14 and 16 designate generally pairs of molded article receiving devices which are of identical structure; however, the devices 12 and 13 are of opposite hand relative to the devices 14 and 16, respectively. Figs. 1 and 2 show a fixed mold platen 21 cooperating with relatively movable platens 17, 18 and 19. The reference numeral 24 designates a sprue bar leading from an injection molding machine (not shown) delivering molding compound to a mold cavity via usual and customary runners and gates indicated by the reference numerals 26 and 27, respectively. The mold for a molded article 28 (Fig. 1) is composed of a mold element or core 29 carried by movable platen 19 and cavity 31 supported by cooperating movable platen 17. The reference numeral 32 designates, schematically a specific molded article receiving device which in Fig. 1 is shown in its operative or molded article receiving position. For purposes of subsequent claiming this invention this position of the receiving device 32 may be described as its second or receiving position and the position of the device in Fig. 2 its first position or release position. The article receiving device 32 is movable to and from laterally as indicated by the arrow labelled A by a transfer means in a manner and by means which will become more apparent as the specification proceeds, from the position of Fig. 1 to the position of Fig. 2 carrying along a newly molded article 28. As is apparent in Figs. 2, 3 and 4, the molded article receiving device 32 moves into register with a fixed chute member 34 which forms a continuation of the article receiving device effective to dispense molded articles in a manner which will be explained in greater detail in connection with Figs. 5, 6 and 7. It is to be particularly noted that the article receiving device 32 withdraws from the mold area clutching the newly molded article 28 in positive fashion thus clearing the mold set for prompt closure with little or no delay in its repetitive cycle. Turning now to Figs. 3, 4 and 5, details of the article receiving device 32 will be described. Only one device will be described with the understanding that all the receiving devices indicated generally at 12, 13, 14 and 16 in Figs. 1 and 2 are of similar structure but exist in pairs of opposite hand. The device 32 includes a vertical back plate or receiving plate 36 bounded by sidewalls 37 and 38. The back plate is formed with two apertures 39 and 41 whose vertical spacing is dictated by the vertical spacing of mold cavities of the top and bottom mold sets of the two-tiered stack mold of Figs. 1 and 2. That is, the receiving plate 36 is positioned in elevation at a point relative to the two-tiered mold set so that the apertures 39 and 41 fall into register with respective mold cavities of each tier, i.e. aperture 39 registers with mold core 29 and mold cavity 31 in the top tier mold set of Fig. 1 and aperture 41 falls into register with the mold elements of the lower tier directly below. Apertures 39 and 41 communicate with a channel 42 secured to the back side of receiving plate 36 closed at its upper end by a plate 43 and terminating at its lower end in a fluid tight fitting 44 connected to a flexible tube 45 leading to a source of vacuum. The article receiving device 32 is supported by top and bottom angle brackets 46 and 47 which receive top and bottom guides or aligning rods 35 and 40, along which the receiving device 32 reciprocates and is supported moving to and from the article receiving position of Fig. 1 to the release position of Fig. 2. Referring to Figs. 6 and 7 it is apparent that the rods 35 and 40 are supported at their extremities in spaced blocks 49 and 50 in turn secured to the platen supporting the core side of the mold, such as platens 19 and 21, in any suitable fashion such as by machine screws. Note that each bracket 46 and 47 carries a projecting cam follower 51 and 52, respectively, which engage mating top and bottom (only top cam shown) cam plates secured to the cavity side of the mold such as to platens 17 and 18 so that the cooperation between the cam plates and followers operates to move the articles receiving plates 32 to and from as the die set opens and closes in a manner that will be more apparent shortly. As is apparent in Figs. 1, 2, 4 and 5 core platens such as the platen 19 and 21 (Fig. 1) support a curved slide or chute 53 fixed to the platen in the article release position as indicated by the letter R. The chute 53 is dimensioned in horizontal cross-section to match the corresponding cross-section of the receiving device 32 and one chute 53 is provided for each receiving device so that when the device is in the release position R the chute and the article receiving device are in register providing a transition from a vertical slide to a horizontal slide. The vertical article receiving device 32 and the contiguous chute 53 are provided with a cover plate 54 fixed at the release position to keep molded articles from tumbling. Referring to Figs. 1, 6 and 7 the cam and follower arrangement will be described. A paddle shaped cam 56 having a body 57 and a tongue 63 with parallel cam tracks 58 and 59 (see fig. 6) terminating in cam tracks 61 and 62 is secured by bolting body 57 to a central position on a cavity platen 18 such as indicated in dotted lines in Fig. 1. Hydraulic or pneumatic cylinders 64 and 66 supported by fixed blocks 49 and 50 have piston rods 67 and 68, respectively connected to wings 69 and 71 of angle brackets are operative to maintain a load on the angle brackets 46-46 tending to draw the brackets together along their guide rods into contact with the cam tracks. Since the followers 51 (top) and 52 (bottom) are carried by the angle brackets 46 (top) and 47 (bottom) which in turn are slidably supported on the guide rods 35-35 the pistons operate to keep the followers snugly in contact with their respective cam tracks. In the paired (top and bottom) angle bracket arrangement shown in Figs. 3, 4 and 5 vertical alignment of the article receiving devices (as they travel from station to station) is maintained by providing a cam-follower set at the top and at the bottom of the tiered or stack mold set. Only the complete top set is shown. Operation With the mold cavity C in the closed condition (Fig. 2) and the article receiving device 32 in its article release position R the followers 51-51 are in the position shown in Figs. 6 and 7. In timed sequence the movable platen 18 moves from the closed position of Fig. 2 to the open position of Fig. 1 and a molded article is retained on the core 29. Movable platens 17 and 18 move in unison for a partial stroke along with movable platen 19. Platens 17 and 18 are arrested and platen 19 continues its stroke until its molds open. Platen 21 remains fixed at all times. During the course of opening the mold cavity followers 51-51 follow their respective cam tracks 58-59 and 61-62 permitting pistons 64 and 66 to draw a pair of article receiving devices 32-32 into the proximity of the stacked cores 29-29. A blast of air is applied through channels 72 and 73 ejecting the newly molded articles into contact with receiving plate 36 in the region of and into the proximity of plate apertures 39 and 41. Simultaneously a vacuum is drawn through conduit 45, channel 42 and apertures 39 and 41 effective to retain the molded articles releasably in the position shown in Fig. 1. While maintaining the vacuum the molding cycle continues and the mold elements 27 and 29 are returned to their closed cavity position of Fig. 2. During this occurrence cam and following action in opposition to pushers 64 and 66 drives the article receiving devices 32-32 apart to their respective article release positions R as shown in Fig. 2. When the receiving devices are in register with their mating chutes 53-53 the vacuum is broken and the articles are released and slide neatly down and out the chute to the next process station; each and every article discharging in the same physical disposition or same orientation relative to the orientation of every other article. Method The method of the invention involves the provision of a continuously cycling injection mold set of one or more mold cavities of single or multiple tier (stack) arrangement where it is desired to mold, collect and discharge molded articles in accord with a uniform physical orientation. Assuming that an article has been molded the die or mold elements forming the mold cavity are separated and during the course of this occurrence a collector member is moved into register with the molded article. The article is then blown off the die element to which it clings and simultaneously a vacuum is applied to the collector member to secure the molded articles releasably to the collector member. Without hesitation the die elements cycle to a closed position and during this occurrence the collector member moves clear of the die elements to an article release station. At the release station the vacuum is broken and the article is free to follow a restricted path B in response to gravity where the article and each succeeding article is deposited in said uniform physical orientation. This invention may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.

Claims: A method of removing molded articles (28) sequentially and continuously from a continuous cycling injection molding machine where all molded articles (28) are collected in a uniform physical arrangement or orientation comprising the steps of: providing relatively movable mold platens (17 and 19, 18 and 21) formed with cooperating mold elements (29) and mold cavities (31), molding an article (28) within said cavity (31), providing an article receiving station (12,13,14,16) and a separate article release station (53), separating the platens (17,19,18,21) whereby the molded article (28) is retained upon one mold element (29) of one platen (19,21), placing an article receiving member (12,13,14,16) into the proximity of said article (28) at a receiving position, ejecting the article (28) from the mold element (29) and driving it into contact with the receiving member (12,13,14, 16), retaining the article on the receiving member (12,13,14,16), moving the receiving station (12,13,14,16) during the separating of the platens (17,19,18,21) away from the mold cavity (31) to said release station (53) which are arranged in proximity of the mold elements (29) on the same platen (19,21) and releasing the molded article (28) from said receiving station (12,13, 14,16) at the said release station whereby the article (28) is free to drop by gravity to a station for further processing. A method according to claim 1 characterized by air ejecting the article (28) from the platen (19,21) and driving it into contact with the receiving station (12,13,14,16) and using a vacuum to retain the article on the receiving station (12,13,14,16). A method of claim 1 or 2 characterized by changing the path of the released article (28) from a first line of action to a second line (B) during its free drop. Injection molding apparatus for continuously molding articles (28) including a pair of relatively movable mold platens (17 and 19, 18 and 21), each platen (17,19,18,21) supporting mold elements (29) cooperating with mold cavities (31), said platens cycling continuously through a cavity opening stroke and a cavity closing stroke, a device (12,13,14,16) for receiving and dispensing molded articles (28) in a uniform physical orientation comprising a receiving device (32) carried by one of said platens (17,19,18,21), said receiving device (32) being movable from a first position defining a release position near a release station (53) to a second position defining a receiving position in proximity to a molded article retained on one of said platens (17,18,19,21), and transfer means (56) carried by one of said platens (17,18,19,21) responsive to relative motion between said platens (17,18,19,21) for driving said receiving device (32) from said first position to said second position, characterized in that the release station (53) is also arranged on said platen (18,18,19,21) which carries the receiving device (32). The apparatus of claim 4 characterized in that one platen (21) is fixed and the other platen (17,18,19) is movable and the receiving device (32) is carried by the movable platen (17,18 or 19). The apparatus of claim 4 characterized in that one platen (21) is fixed and the other platen (17,18,19) is movable and the transfer means is carried by the movable platen (17,18 or 19). The device of at least one of the claims 4-6 characterized in that at least one cam follower (51,52) is arranged on the one platen (21) coorperating with a cam (56) as the transfer means fixed to the other platen (18). The device of claim 7 characterized by fluid means (64,66) for urging the cam follower (51,52) into firm contact with said cam (56). The device of at least one of the claims 4-8 characterized in that said platen (19,21) supports a chute device (34) fixed at said release position, said chute (34) providing a continuation of said receiving device (32) when said device (32) is in the release position. The device of at least one of the claims 4 - 9 characterized in that said receiving device (32) is formed with an aperture (39,41) and a communicating channel (42) leading to a source of vacuum, said aperture (39,41) in the proximity of a molded article (28) when said receiving device (32) is in said second or receiving position whereby a molded article (28) thrust upon the receiving device (32) is retained by vacuum applied through said aperture (39,41). The device of claim 9 or 10 characterized in that said platen (19,21) supports a cover plate (54) fixed at said release position in register with said chute (34) which cooperates with said receiving device (32) at said release position to keep articles (28) from tumbling. The device of at least one of the claims 9 -11 characterized in that said chute (34) defines a first path generally parallel to said receiving device (32) curving to a second path (B) generally perpendicular to said first path.

Inventors: SCHAD, ROBERT D.
Applicants: HUSKEY INJECTION MOLDING SYSTEMS LTD.
Application year: 1986
Main classification: B29C45
IPC codes: B29C45, B29C31