WO2008138092A1

WO2008138092A1 - An adjustable cam system for a moulding machine

Info

Publication number: WO2008138092A1
Application number: PCT/CA2007/000816
Authority: WO
Inventors: Rainer Kintzinger
Original assignee: Husky Injection Molding Systems Ltd.
Priority date: 2007-05-09
Filing date: 2007-05-09
Publication date: 2008-11-20

Abstract

According to non-limiting embodiments of the present invention, there is provided an adjustable cam (216, 216') and an adjustable cam system (218) for a molding system (100) and a method of use thereof. An adjustable cam (216, 216') is provided, the adjustable cam (216, 216') comprising a first cam body (302, 302') configured for attachment to a first molding structure; a second cam body (304, 304') slidably engageable with the first cam body (302, 302'); the first cam body (302, 302') and the second cam body (304, 304') jointly defining a path of travel (310) for a cam follower (214); a clamping plate (306, 306') for selectively fixing position of the second cam body (304, 304') along the first cam body (302, 302') in an interference fit.

Description

AN ADJUSTABLE CAM SYSTEM FOR A MOLDING MACHINE

FIELD OF THE INVENTION

The present invention generally relates to, but is not limited to, molding systems, and more specifically the present invention relates to, but is not limited to, an adjustable cam and an adjustable cam system for use in a molding system, and a method of use thereof.

BACKGROUND OF THE INVENTION

Molding is a process by virtue of which a molded article can be formed from molding material by using a molding system. Various molded articles can be formed by using the molding process, such as an injection molding process. One example of a molded article that can be formed, for example, from polyethelene terephalate (PET) material is a preform that is capable of being subsequently blown into a beverage container, such as, a bottle and the like.

As an illustration, injection molding of PET material involves heating the PET material (ex. PET pellets, PEN powder, PLA, etc.) to a homogeneous molten state and injecting, under pressure, the so- melted PET material into a molding cavity defined, at least in part, by a female cavity piece and a male core piece mounted respectively on a cavity plate and a core plate of the mold. The cavity plate and the core plate are urged together and are held together by clamp force, the clamp force being sufficient enough to keep the cavity and the core pieces together against the pressure of the injected PET material. The molding cavity has a shape that substantially corresponds to a final cold-state shape of the molded article to be molded. The so-injected PET material is then cooled to a temperature sufficient to enable ejection of the so-formed molded article from the mold. When cooled, the molded article shrinks inside of the molding cavity and, as such, when the cavity and core plates are urged apart, the molded article tends to remain associated with the core piece. Accordingly, by urging the core plate away from the cavity plate, the molded article can be demolded, i.e. ejected off of the core piece. Ejection structures are known to assist in removing the molded articles from the core halves. Examples of the ejection structures include stripper plates, ejector pins, etc.

When dealing with molding a preform that is capable of being blown into a beverage container, one consideration that needs to be addressed is forming a so-called "neck region". Typically and as an example, the neck region includes (i) threads (or other suitable structure) for accepting and retaining a closure assembly (ex. a bottle cap), and (ii) an anti-pilferage assembly to cooperate, for example, with the closure assembly to indicate whether the end product (i.e. the beverage container that has been filled with a beverage and shipped to a store) has been tampered with in any way. The neck region may comprise other additional elements used for various purposes, for example, to cooperate with parts of the molding system (ex. a support ledge, etc.). As is appreciated in the art, the neck region can not be easily formed by using the cavity and core halves. Traditionally, split mold inserts (sometimes referred to by those skilled in the art as "neck rings") have been used to form the neck region.

A typical neck ring comprises a first neck ring half and a second neck ring half, which cooperate together to form the neck region of the preform. A plurality of first neck ring halves in the mold is coupled to a first plurality of slides; the first plurality of slides, in turn, is connected together for movement in unison. Similarly, a plurality of second neck ring halves is also coupled to a second plurality of slides; the second plurality of slides, in turn, is connected together for movement in unison. For example, this connection of the first plurality of slides and the second plurality of slides can be implemented by means of respective connecting bars and the like. A first cam system can be used to control the lateral movement of the plurality of first neck ring halves via a first set of connecting bars. A second cam system can be used to control the lateral movement of the plurality of second neck ring halves via a second set of connecting bars. Alternatively, a single cam system can be used to control lateral movement of both the first and the second neck ring halves relative to each other, for example, by means of a mechanical linkage between the first and second sets of connecting bars. The first and second cam systems can be substantially identical to each other and will be referred to herein below as a cam system.

A typical cam system includes a cam and a cam follower. The cam defines a path of travel for the cam follower to follow. Generally speaking, the cam system translates movement of a stripper plate along an operating axis of the molding system into lateral movement of neck ring halves. To that extent, the path of travel includes a generally curved portion spaced a pre-determined distance from a starting extreme of the path of travel. The distance between the starting extreme and the generally curved portion corresponds to a height of a preform to be produced.

Due to various business considerations, an entity operating the molding system may choose to re- configure the molding system, for example, to change the shape of the preform to be produced. For example, the entity operating the molding system may choose to change the molding cavities (for example, by exchanging mold cavity inserts, etc.) to produce preforms having a larger height. Should this occur, the entity operating the molding system will need to adjust the path of travel defined by the cam. Traditionally, this was done by exchanging an old cam system for a new cam system, the new cam system corresponding to the new layout and configuration of the mold. As will be appreciated, this means that the entity operating the molding system will incur unnecessary expenses both in direct costs associated with purchasing/producing the new cam systems, as well as wasted labor hours required for replacing the cam systems.

US patent 4,497,624 issued to Brun et al. on February 5, 1985 discloses an injection molding machine that includes inter alia thread splits for forming threads on a portion of each molded article with each of the thread splits being coupled to an actuator for causing relative movement of the thread splits. The actuator is in turn coupled to cam followers which ride within a track. The track includes an insert which defines a ramp or incline which, interacting with the cam followers, causes the actuator to move the thread splits engaging the molded article in such a way to release the article. The adjustability of the position of the track inserts are realized by a pair of slots and a pair of corresponding bolts (as is best seen in Figure 2 of the US patent 4,497,624).

US patent 5,531,588 issued to Brun, Jr et al. on July 2, 1996 teaches an adjustable cam track for an injection molding machine that includes a set of guides coupled to a moveable platen for guiding the movement of space defining surfaces which are movably mounted to a stripper plate as it moves with respect to the movable platen. A set of cam followers coupled to the space defining surfaces cause relative movement of each pair of surfaces to release molded articles previously stripped from the molds of the molding machine. A set of cam inserts engage the cam followers and are adjustably positionable with respect to the guides to adjust the point of release of the molded articles. Each guide includes a pair of guide walls forming a channel defining two limits of position of the cam follower engaged therein. Each cam insert is received between the guide walls and includes a pair of cam insert walls spaced apart by a distance about equal to the size of the cam follower engaged therein to define a path of movement for the cam follower between the two limits of position. Each cam insert includes a complex structure of a first toothed rack, while a second toothed rack is removably fixed to each guide and engages the first toothed rack to fix the position of each cam insert relative to each guide only at certain preselected locations to coordinate the operation of all the cam followers thereby avoiding any wear imbalance.

US patent 6,461,141 issued to Harrison et al. teaches an adjustable cam track for a mold assembly including a first mold portion, a second mold portion movable with respect to the first mold portion, a third mold portion movably interposed between the first and second portions and having at least one pair of space defining surfaces which together with the first and second mold portions defines in a closed position space for receiving plastic material to form at least one molded article. The adjustable cam track includes a guide coupled to the second mold portion, the guide defining a first portion of the adjustable cam track and a cam insert including a second portion of the adjustable cam track defining a point of release of the molded article from the space defining surfaces, the cam insert being adjustably positionable with respect to the guide to adjust the point of release. The first portion of the cam track also includes a ramp to an intermediate portion defining a pre-release position of the space defining surfaces so that the molded article is loosely retained by the space defining surfaces from the time the cam follower engages the ramp defining the onset of prerelease until the cam follower reaches the point of full release to facilitate placement of the molded article into an article receiver inserted into the interval between the first mold portion and the molded article at the culmination of the molding cycle.

SUMMARY OF THE INVENTION

According to a first broad aspect of the present invention, there is provided an adjustable cam. The adjustable cam comprises a first cam body configured for attachment to a molding structure; a second cam body slidably engageable with the first cam body; the first cam body and the second cam body jointly defining a path of travel for a cam follower; a clamping plate for selectively fixing position of the second cam body along the first cam body in an interference fit.

According to a second broad aspect of the present invention, there is provided an adjustable cam system. The adjustable cam system comprises a cam follower configured for attachment to a mold element to be driven; an adjustable cam comprising a first cam body configured for attachment to a molding structure; a second cam body slidably engageable with the first cam body; the first cam body and the second cam body jointly defining a path of travel for the cam follower; a clamping plate for selectively fixing position of the second cam body along the first cam body in an interference fit.

According to a third broad aspect of the present invention, there is provided an interference fit interface defined, in an operating position, between a first linking structure associated with a first cam body configured for attachment to a first molding structure; a second linking structure associated with a second cam body slidably linked to the first cam body; the first cam body and the second cam body jointly defining a path of travel for a cam follower; a clamping plate configured in an interference fit fixed arrangement.

According to a fourth broad aspect of the present invention, there is provided an interface defined between a first cam body configured for attachment to a first molding structure; a second cam body slidably linked to the first cam body; the first cam body and the second cam body jointly defining a path of travel for a cam follower; a clamping plate selectively actuatable between a sliding arrangement and an interference fit locked arrangement, wherein the interface comprises a sliding interface when the clamping plate is in the sliding arrangement; the interface comprises an inference fit fixed interface when the clamping plate is in the interference fit fixed arrangement.

According to another broad aspect of the present invention, there is provided a method of adjusting an adjustable cam, the adjustable cam comprising a first cam body and a second cam body slidably linked to the first cam body for jointly defining a path of travel for a cam follower; a clamping plate for selectively fixing position of the second cam body along the first cam body in an interference fit.

The method comprises entering the clamping plate into a sliding arrangement; sliding the second cam body along the first cam body to a desired position; entering the clamping plate into an interference fit fixed arrangement to fix the second cam body and the first cam body in the desired position.

According to yet another broad aspect of the present invention, there is provided a method implemented in an adjustable cam system, the adjustable cam system comprising an adjustable cam, the adjustable cam comprising a first cam body and a second cam body slidably linked to the first cam body for jointly defining a path of travel for a cam follower; a clamping plate for selectively fixing position of the second cam body along the first cam body in an interference fit. The method comprises at a first instance in time attaching the first cam body to a first molding structure; sliding the second cam body along the first cam body to a first desired position; securing the clamping plate to the second cam body to fix the second cam body in the first desired position. The method further comprises, at a second instance in time after the first instance in time, entering the clamping plate into a sliding arrangement; sliding the second cam body along the first cam body to a second desired position; entering the clamping plate into an interference fit fixed arrangement to fix the second cam body in the first desired position.

According to yet another broad aspect of the present invention, there is provided a molding system of a type having a movable platen, a fixed platen and an injection unit. The molding system comprises a first mold half associated with one of the movable platen and the fixed platen; a second mold half associated with the other one of the movable platen and the fixed platen; a stripper plate associated with one of the fixed platen and the movable platen , the stripper plate comprising a plurality of split mold inserts; an adjustable cam system configured to control lateral movement of the plurality of split mold inserts, a cam follower configured for attachment to a connecting bar associated with the plurality of split mold inserts; an adjustable cam comprising a first cam body configured for attachment to one of the first mold half and the second mold half; a second cam body slidably engageable with the first cam body; the first cam body and the second cam body jointly defining a path of travel for the cam follower; a clamping plate for selectively fixing position of the second cam body along the first cam body in an interference fit. A technical effect, amongst others, of the aspects of the present invention may include provision of an adjustable cam, which is both robust in construction and provides means for securely adjusting a path of travel for a cam follower. Another technical effect of the present invention may include ability to maintain constant orientation for the pre-opening guide in respect to a start extreme of the path of travel. It should be expressly understood that not all of the technical effects, in their entirety, need be realized in each and every embodiments of the present invention.

DESCRIPTION OF THE DRAWINGS

A better understanding of the 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:

Figure 1 is a schematic representation of a molding system 100 according to a non-limiting embodiment of the present invention.

Figure 2 is a perspective view of a mold assembly 202 of the molding system 100 of Figure 1, according to a non-limiting embodiment of the present invention.

Figure 3 is a perspective front view of an adjustable cam 216 of the mold assembly 202, according to a non-limiting embodiment of the present invention.

Figure 4 is a perspective back view of the adjustable cam 216 of Figure 3, according to a non- limiting embodiment of the present invention.

Figure 5 is a perspective front view of the adjustable cam 216 of Figure 3 with a path of travel for a cam follower adjusted to a different height, according to a non-limiting embodiment of the present invention.

Figure 6 is a perspective view of an adjustable cam 216 according to another non-limiting embodiment of the present invention.

The drawings are not necessarily to scale and are may be illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the exemplary embodiments or that render other details difficult to perceive may have been omitted.

DETAILED DESCRIPTION OF EMBODIMENTS With reference to Figure 1, there is depicted a non-limiting embodiment of a molding system 100 which can be adapted to implement embodiments of the present invention. For illustration purposes only, it shall be assumed that the molding system 100 comprises an injection molding system for processing molding material, such as, PET for example. However, it should be understood that in alternative non-limiting embodiments, the molding system 100 may comprise other types of molding systems, such as, but not limited to, compression molding systems, metal molding systems and the like. It should be further understood that embodiments of the present invention are applicable to the molding system 100 incorporating any multicavitation mold, including PET molds, thinwall articles molds, closures molds and the like.

Within the non-limiting embodiment of Figure 1, the molding system 100 comprises a fixed platen 102 and a movable platen 104. The molding system 100 further comprises an injection unit 106 for plasticizing and injection of molding material. In operation, the movable platen 104 is moved towards and away from the fixed platen 102 by means of stroke cylinders (not shown) or any other suitable means. Clamp force (also referred to as closure or mold closure tonnage) can be developed within the molding system 100, for example, by using tie bars 108, 110 and a tie-bar clamping mechanism 112, as well as (typically) an associated hydraulic system (not depicted) that is usually associated with the tie-bar clamping mechanism 112. It will be appreciated that clamp tonnage can be generated using alternative means, such as, for example, using a toggle-clamp arrangement (not depicted) or the like.

A first mold half 114 can be associated with the fixed platen 102 and a second mold half 116 can be associated with the movable platen 104. In the specific non-limiting embodiment of Figure 1, the first mold half 114 comprises one or more mold cavities 118. As will be appreciated by those of skill in the art, the one or more mold cavities 118 may be formed by using suitable mold inserts or any other suitable means. As such, the first mold half 114 can be generally thought of as a "mold cavity half. The second mold half 116 comprises one or more mold cores 120 complementary to the one or more mold cavities 1 18. As will be appreciated by those of skill in the art, the one or more mold cores 120 may be formed by using suitable mold inserts or any other suitable means. As such, the second mold half 116 can be generally thought of as a "mold core half.

The first mold half 114 can be coupled to the fixed platen 102 by any suitable means, such as a suitable fastener (not depicted) or the like. The second mold half 116 can be coupled to the movable platen 104 by any suitable means, such as a suitable fastener (not depicted) or the like. It should be understood that in an alternative non-limiting embodiment of the present invention, the position of the first mold half 114 and the second mold half 116 can be reversed and, as such, the first mold half 114 can be associated with the movable platen 104 and the second mold half 1 16 can be associated with the fixed platen 102.

In an alternative non-limiting embodiments of the present invention, the fixed platen 102 need not be stationary and may as well be moved in relation to other components of the molding system 100.

Figure 1 depicts the first mold half 114 and the second mold half 116 in a so-called "mold open position" where the movable platen 104 is positioned generally away from the fixed platen 102 and, accordingly, the first mold half 1 14 is positioned generally away from the second mold half 116. For example, in the mold open position, a molded article (not depicted) can be removed from the first mold half 114 and/or the second mold half 116. In a so-called "mold closed position" (not depicted), the first mold half 114 and the second mold half 116 are urged together (by means of movement of the movable platen 104 towards the fixed platen 102) and cooperate to define (at least in part) a molding cavity (not depicted) into which the molten plastic (or other suitable molding material) can be injected, as is known to those of skill in the art. It should be appreciated that one of the first mold half 114 and the second mold half 116 can be associated with a number of additional mold elements, such as for example, one or more leader pins (not depicted) and one or more leader bushings (not depicted), the one or more leader pins cooperating with one more leader bushings to assist in alignment of the first mold half 114 with the second mold half 116 in the mold closed position, as is known to those of skill in the art. The molding system 100 can further comprise a robot 122. Generally speaking, the robot 122 can be used for molded article removing and/or post-mold cooling.

The molding system 100 further comprises a split mold insert assembly 124, associated with the second mold half 1 16 and disposed, in use, between the first mold half 114 and the second mold half 116.

Naturally, the molding system 100 may comprise a number of additional components, such as a hot runner (not depicted) associated, for example, with the fixed platen 102. Furthermore, the molding system 100 may optionally or additionally comprise auxiliary equipment (not depicted), such as humidifiers, heaters and the like. All this equipment is known to those of skill in the art and, as such, will not be discussed at any length here.

It should be expressly understood that the molding system 100 may have other configurations and the description presented above has been provided as an example only and is not intended to be limiting in any form. In other non-limiting embodiments of the present invention, the molding system 100 can have other configurations with more or fewer components. Configuration of the split mold insert assembly 124 will now be described in greater detail with reference to Figure 2. Figure 2 depicts a mold assembly 202 that can be used within the molding system 100 of Figure 1, according to a non-limiting embodiment of the present invention. The mold assembly 202 comprises the second mold half 1 16 and the split mold insert assembly 124. Mounted on the second mold half 116 is one or more mold cores 120 (with only a single instance thereof being depicted in Figure 2). In the specific non-limiting embodiment of the present invention, the mold assembly 202 further comprises an adapter plate 204 that can be optionally used to control a so- called stack height. It should be expressly understood that the adapter plate 204 is an optional component and, as such, may be omitted in alternative embodiments of the present invention.

Mounted on the split mold insert assembly 124 is a plurality of split mold inserts 206. More specifically, the plurality of split mold inserts are mounted on a plurality of split mold insert slides 208. In the specific non-limiting embodiment depicted in Figure 2, the plurality of split mold inserts 206 can be said to be mounted on the plurality of split mold insert slides 208 in a "front-face" configuration, as is more specifically described in two commonly owned US patent applications bearing serial number 11/740,564 and 11/740,594, respectively, filed with the United States Patent Office on April 26, 2007 (bearing attorney docket numbers HA1095-0-US and HB1095-0-US respectively), the content of which is hereby incorporated by reference in its entirety. It should be expressly understood, that the plurality of split mold inserts 206 can be mounted on the plurality of split mold insert slides 208 in any other suitable configuration, as is known in the art. The plurality of split mold insert slides 208 are arranged in a sliding relationship with the split mold insert assembly 124. In the specific non-limiting embodiment depicted in Figure 2, the plurality of split mold insert slides 208 are coupled to the split mold insert assembly 124 by means of linear bearings 240. However, any other suitable means known in the art can be used for interconnecting the plurality of split mold insert slides 208 and the split mold insert assembly 124.

Plurality of split mold inserts 206 includes a subset of left split mold inserts 206a and a subset of right split mold inserts 206b (as viewed from above in Figure 2). The subset of left split mold inserts 206a is mounted onto a plurality of first split mold insert slides 208a and the subset of right split mold inserts 206b is mounted onto a plurality of second split mold insert slides 208b. The plurality of first split mold insert slides 208a is operatively coupled to a first slide connecting bar 210. Similarly, the plurality of second split mold insert slides 208b is operatively coupled to a second slide connecting bar (not depicted, as obstructed from the view in Figure 2). The connection between the plurality of split mold insert slides 208 and the plurality of split mold inserts 206 can be realized by any known type of a permanent or removable fastener, such as a bolt, by means of welding and the like. The first slide connecting bar 210 is operatively connected to a cam follower 214. Again, the connection between the first slide connecting bar 210 and the cam follower 214 can be realized by any suitable known means, such as, for example, a bolt or any other suitable permanent or removable fastener. Accordingly, in this embodiment of the present invention, the first slide connecting bar 210 can be thought of as a mold element to be driven by the cam follower 214.

The mold assembly 202 further comprises an adjustable cam 216 configured to cooperate, in use, with the cam follower 214. Accordingly, the cam follower 214 and the adjustable cam 216 can be said to form part of an adjustable cam system 218. The configuration of the adjustable cam system 218 will be described in greater detail momentarily. For the sake of completing discussion of Figure 2 and generally speaking, the purpose of the adjustable cam system 218 is to translate an operational movement of the split mold insert assembly 124 along an operation axis depicted in Figure 2 at "Al" into a lateral movement of the plurality of split mold insert slides 208 and the plurality of split mold inserts 206 operatively connected thereto. More specifically, in the specific non-limiting embodiment of Figure 2, the adjustable cam system 218 controls the lateral movement of the plurality of first split mold insert slides 208a and the subset of left split mold inserts 206a.

With reference to Figure 3, configuration of a non-limiting embodiment of the adjustable cam 216 will now be described in greater detail. The adjustable cam 216 comprises a first cam body 302, a second cam body 304 and a clamping plate 306. The first cam body 302 can be coupled, in use, to the second mold half 116. To that extend, the first cam body 302 comprises a coupling arrangement 308. In the specific non-limiting embodiment of Figure 3, the coupling arrangement 308 comprises a bore for receiving therethrough a bolt (or another suitable type of a fastener) for attachment the first cam body 302 to a molding structure, such as, the second mold half 116, for example. However, in alternative non-limiting embodiments of the present invention, the coupling arrangement 308 can be realized in a number of alternative configurations, as will be appreciated by those of skill in the art. As is best seen in Figure 4, the clamping plate 306 comprises a locking arrangement 402. In the specific non-limiting embodiment of Figure 4, the locking arrangement 402 comprises a plurality of bores that cooperate with a plurality of complementary bores, which can be threaded (not depicted) disposed on the second cam body 304, for receiving therethrough a plurality of fasteners (such as, for example, a plurality of bolts) to lock the clamping plate 306 in an operating position, as will be described in greater detail herein below. It should be expressly understood that the exact number of instances of the locking arrangement 402 used is not particularly limited and various alternatives are possible. In the specific non-limiting embodiment being described herein, eight instances of the locking arrangement 402 are used. However, this need be so in every embodiment of the present invention. Returning to Figure 3, the first cam body 302 and the second cam body 304 cooperate to define a path of travel 310 that is configured to cooperate with a complementary portion of the cam follower 214 to guide the cam follower 214 along a pre-determined path of motion. The path of travel 310 is defined by cooperating grooves defined within the first cam body 302 and the second cam body 304. More specifically, the path of travel 310 is defined by a first groove 312a defined in the first cam body 302 and a second groove 312b defined in the second cam body 304. A portion of the first groove 312a and a portion of the second groove 312b can overlap and, as is the case with the specific non-limiting embodiment of Figure 3, this overlap can form an overlapping portion 314.

The first groove 312a is generally U-shaped and is associated with a first extreme portion 316 that defines a starting point of travel for the cam follower 214. Similarly, the second groove 312b is generally U-shaped and is associated with a second extreme portion 318 that defines a terminating point of travel for the cam follower 214. The second groove 312b is further associated with a bend

320 for defining a point of initiating the lateral movement of the plurality of first split mold insert slides 208a and the subset of left split mold inserts 206a. The path of travel 310 can be said to be associated with a path length, as measured between the starting point of travel and the terminating point of travel or, in other words, between the first extreme portion 316 and the second extreme portion 318.

The first cam body 302 and the second cam body 304 are slidably linked to each other. To that extent, the first cam body 302 comprises a first linking structure 322 and the second cam body 304 comprises a second linking structure 324. In the specific non-limiting embodiment of Figure 3, the first linking structure 322 and the second linking structure 324 are arranged in a "key and keyhole" sliding arrangement. To that extent, the first linking structure 322 comprises two pillars disposed on the opposing sides of the first cam body 302 and the second linking structure 324 comprises two slots corresponding to the two pillars. For the avoidance of doubt, it should be expressly understood that the shape of the first linking structure 322 and the second linking structure 324 is not particularly limiting. As such, in alternative non-limiting embodiments of the present invention, the shape of the first linking structure 322 and the second linking structure 324 can be semi-circular and the like, "T- shaped" and the like.

The first linking structure 322 is associated with a first height "Hl" and the second linking structure is associated with a second height "H2". The first height "Hl" is larger than the second height H2 by a pre-determined amount so as to achieve the following function. When the clamping plate 306 is partially or completely detached from the second cam body 304, the first linking structure 322 and the second linking structure 324 can freely slide in relation to each other (referred to herein below as a "sliding arrangement"). Recalling that the locking arrangement 402 can comprise a plurality of bores that cooperate with a plurality of complementary bores (not depicted) disposed on the second cam body 304 for receiving therethrough a plurality of fasteners (such as, for example, a plurality of bolts), the partial or complete detachment of the clamping plate 306 from the second cam body 304 can be achieved by partially loosening or completely detaching the plurality of fasteners from the plurality of bores. On the other hand, when the clamping plate 306 is secured to the second cam body 304 in the operating position, the clamping plate 306 causes the first linking structure 322 to be clamped within the second linking structure 324 in an interference fit (referred to herein below as a "interference fit fixed arrangement"). For the avoidance of doubt, it should be understood that in the interference fit arrangement, the clamping plate 306 clamps the second cam body 304 and the first cam body 302 and retains them in a desired position by means of the interference fit between the first linking structure 322 and the second linking structure 324.

Accordingly, a position of the second cam body 304 along the first cam body 302 can be adjusted to a plurality of selectable positions. To achieve this, the adjustable cam 216 is entered into the slidable arrangement and a given one of the plurality of selectable positions is chosen by sliding the second cam body 304 along the first cam body 302. The given one of the plurality of selectable positions is then fixed by entering the adjustable cam 216 into the interference fit fixed arrangement. By selecting the given one of the plurality of selectable positions, the path length for the cam follower 214 to follow can be adjusted. The result of such an adjustment is best seen when comparing two states of the adjustable cam 216 as depicted in Figure 3 and Figure 5, respectively. It can be clearly seen that the path length as measured between the first extreme portion 316 and the second extreme portion 318 in Figure 5 is larger than the path length as measured between the first extreme portion 316 and the second extreme portion 318 in Figure 3. Accordingly, a configuration of the adjustable cam 216 of Figure 5 can be used for handling preform(s) having a larger profile than those handled by a configuration of the adjustable cam 216 of Figure 3. A technical effect of these embodiments of the present invention includes ability to adjust the path length, while maintaining the structure of the adjustable cam 216 relatively simple and relatively robust.

With reference to Figure 6 another embodiment of an adjustable cam 216' will now be discussed in greater detail. The adjustable cam 216^' can be substantially similar to the adjustable cam 216 but for the specific differences discussed herein below and, as such, like elements are depicted with like numerals. The adjustable cam 216' comprises a first cam body 302', a second cam body 304' and a clamping plate 306^'. The first cam body 302' and the second cam body 304' are arranged in a "key and keyhole" sliding arrangement, similar to the first cam body 302 and the second cam body 304. Similarly, the first cam body 302' comprises a first groove 312a', which is generally U-shaped and is associated with a first extreme portion 316'. The second cam body 304' is similarly associated with a second groove 312b', which in turn defines a bend 320'. The first groove 312a' further defines a pre- opening break point 602. The pre-opening break point 602 is a protrusion or other formation along the first groove 312a" that cooperates with the cam follower 214 to provide for a pre-opening motion of the cam follower 214, which translates into a pre-opening motion of the subset of left split mold inserts 206a. As will be appreciated by those of skill in the art, the pre-opening of the plurality of split mold inserts 206 prevents sticking and potential jerking of the molded articles during the de- molding part of the molding cycle. A technical effect of this embodiment of the present invention may include ability to pre-open the plurality of split mold inserts 206, which may result in a substantially problem-free opening of the plurality of split mold inserts 206, once the cam follower hits the bend 320". Another technical effect achieved by placing the pre-opening break point 602 into the first groove 312a" is the ability to maintain a constant distance between the first extreme portion 316 and the pre-opening break point 602 irrespective of which given position of the first cam body 302" along the second cam body 304 is selected.

The adjustable cam 216" can further comprise an auxiliary locking structure 604. In the specific non- limiting embodiment of Figure 6, the auxiliary locking structure 604 comprises a first plurality of bores 606 defined in the first cam body 302' and a second plurality of bores 608 defined in the second cam body 304^". The configuration of the first plurality of bores 606 and the second plurality of bores 608 is complementary in that in a given position of the first cam body 302" along the second cam body 304", a given one of the first plurality of bores 606 cooperates with a given one of the second plurality of bores 608 to accept one or more fasteners 610 therethrough. In the example depicted in Figure 6, the first plurality of bores 606 can be threaded and the one or more fasteners 610 can comprise one or more bolts. However, in alternative non-limiting embodiments of the present invention, other types of one or more fasteners 610 can be used. Accordingly, in alternative non-limiting embodiments, the first plurality of bores 606 may or may not need to be threaded. It should be expressly understood that in alternative non-limiting embodiments of the present invention, the auxiliary locking structure 604 may have other configurations, such as, for example, a combination of complementary grooves defined in the first cam body 302" and the second cam body 304" cooperating with one or more fasteners 610, and the like. The auxiliary locking structure 604 can be said to provide auxiliary locking function above the locking function provided by the locking arrangement 402.

It should be noted that in the embodiment depicted in Figure 6, the first cam body 302" is generally "L-shaped". A bottom portion of the "L-shape" defines a coupling arrangement 308', which can be substantially similar to the coupling arrangement 308 described above.

As is best seen in Figure 6 (but also applicable to other embodiments of the present invention), the first cam body 302^" and the second cam body 304" can be said to define an interference fit interface 640. More specifically, when the clamping plate 306" is in the operating position, the clamping plate 306" secures the first cam body 302" and the second cam body 304" in an interference fit defined along the interference fit interface 640. More specifically, the interference fit interface 640 is defined by cooperating portions of a first linking structure 322" and a second linking structure 324".

Given an architecture of an adjustable cam system 218 described with reference to Figures 2-6, it is possible to implement a method for adjusting a cam. More specifically, at a first instance in time, the first cam body 302, 302" is attached to the molding system 100, for example, to the second mold half 116. This can be realized, for example, by using the coupling arrangement 308, 308". The second cam body 304, 304" is slid along the first cam body 302, 302" to a first desired position. The clamping plate 306, 306" is then attached to the second cam body 304, 304"; for example, by using the locking arrangement 402. Alternatively, the clamping plate 306, 306^" can be attached to the second cam body 304, 304^" before the step of sliding of second cam body 304, 304"; and in this case, the clamping plate 306, 306^" is entered into a sliding arrangement, as has been previously described.

At some time thereafter, it shall be assumed that is desirable to adjust the adjustable cam system 218. It will be recalled that, a position of the second cam body 304, 304" along the first cam body 302, 302" can be adjusted to a plurality of selectable positions. To achieve this, the clamping plate 306, 306^" is actuated into the slidable arrangement and a given one of the plurality of selectable positions (i.e. a second desired position) is chosen by sliding the second cam body 304, 304' along the first cam body 302, 302^". The given one of the plurality of selectable positions is then fixed by entering the clamping plate 306, 306' into the interference fit fixed arrangement. By selecting the given one of the plurality of selectable positions, the path length for the cam follower 214 to follow is adjusted.

The description of the embodiments of the present inventions provides examples of the present invention, and these examples do not limit the scope of the present invention. It is to be expressly understood that the scope of the present invention is limited by the claims only. The 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. Having thus described the embodiments of the present invention, 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. An adjustable cam (216, 216") comprising:

a first cam body (302, 302') configured for attachment to a molding structure;

a second cam body (304, 304') slidably engageable with the first cam body (302, 302"); the first cam body (302, 302") and the second cam body (304, 304") jointly defining a path of travel (310) for a cam follower (214);

a clamping plate (306, 306") for selectively fixing position of the second cam body (304, 304") along the first cam body (302, 302") in an interference fit.

2. The adjustable cam (216, 216") of claim 1, said first cam body (302, 302") comprising a first linking structure (322, 322") and said second cam body (304, 304") comprising a second linking structure (324, 324"), said first linking structure (322, 322") and said second linking structure (324, 324") cooperating to provide slidable engagement between said first cam body (302, 302") and said second cam body (304, 304").

3. The adjustable cam (216, 216") of claim 2, wherein said first linking structure (322, 322") is associated with a first height and said second linking structure (324, 324") is associated with a second height, and wherein said first height being larger than said second height to provide said interference fit.

4. The adjustable cam (216, 216") of claim 1, wherein said clamping plate (306, 306") is movable between (i) a sliding position in which it allows for said first cam body (302, 302") to slide in relation to said second cam body (304, 304") and (ii) an interference fit fixed position in which it clamps said first cam body (302, 302") to said second cam body (304, 304") in a given position.

5. The adjustable cam (216, 216^") of claim 4, wherein said clamping plate (306, 306") further comprises a locking arrangement (402) for locking said clamping plate (306, 306") in an operating position.

6. The adjustable cam (216, 216") of claim 5, wherein said locking arrangement (402) comprises a plurality of bores defined in said clamping plate (306, 306^"), wherein said second cam body (304, 304^") comprises a complementary plurality of bores, and wherein said plurality of bores and said complementary plurality of bores are configured to accept a plurality of fasteners to secure said clamping plate (306, 306") in an operating position.

7. The adjustable cam (216, 216') of claim 6, wherein to enter said clamping plate (306, 306^') in said sliding arrangement, said plurality of fasteners are partially engaged.

8. The adjustable cam (216, 216") of claim 6, wherein to enter said clamping plate (306, 306') in said sliding arrangement, said plurality of fasteners are fully disengaged.

9. The adjustable cam (216, 216') of claim 6, wherein to enter said clamping plate (306, 306') in said interference fit fixed arrangement, said plurality of fasteners are substantially fully engaged.

10. The adjustable cam (216, 216') of claim 1, wherein said path of travel (310) is defined by a first groove (312a, 312a') defined in said first cam body (302, 302') and a second groove (312b, 312b') defined in said second cam body (304, 304').

1 1. The adjustable cam (216, 216') of claim 10, wherein said first groove (312a, 312a") further defines a pre-opening break portion.

12. The adjustable cam (216, 216") of claim 1, wherein said first cam body (302, 302') further comprises a coupling arrangement (308, 308") for coupling said first cam body (302, 302') to the first molding structure.

13. The adjustable cam (216') of claim 1, further comprising an auxiliary locking structure (604).

14. The adjustable cam (216") of claim 13, wherein said auxiliary locking structure (604) comprises a first plurality of bores (606) defined in said first cam body (302") and a second plurality of bores (608) defined in said second cam body (304^"), a given one of said first plurality of bores (606) configured to cooperate with a given one of said plurality of second bores and a complementary fastener to provide auxiliary locking.

15. The adjustable cam (216") of claim 13, wherein said auxiliary locking structure (604) comprises a first slot defined in said first cam body (302") and a second slot in said second cam body (304^"), a given portion of said first slot configured to cooperate with a given portion of said second slot and a complementary fastener to provide auxiliary locking.

16. An adjustable cam system (218) comprising:

a cam follower (214) configured for attachment to a mold element to be driven;

an adjustable cam (216, 216") comprising: a first cam body (302, 302^') configured for attachment to a molding structure;

a second cam body (304, 304^') slidably engageable with the first cam body (302, 302'); the first cam body (302, 302^') and the second cam body (304, 304') jointly defining a path of travel (310) for the cam follower (214);

a clamping plate (306, 306') for selectively fixing position of the second cam body

(304, 304') along the first cam body (302, 302') in an interference fit.

17. The adjustable cam system (218) of claim 16, said first cam body (302, 302') comprising a first linking structure (322, 322') and said second cam body (304, 304') comprising a second linking structure (324, 324'), said first linking structure (322, 322') and said second linking structure (324, 324') cooperating to provide slidable engagement between said first cam body (302, 302') and said second cam body (304, 304').

18. The adjustable cam system (218) of claim 17, wherein said first linking structure (322, 322') is associated with a first height and said second linking structure (324, 324") is associated with a second height, and wherein said first height being larger than said second height to provide said interference fit.

19. The adjustable cam system (218) of claim 16, wherein said clamping plate (306, 306") is movable between (i) a sliding position in which it allows for said first cam body (302, 302") to slide in relation to said second cam body (304, 304") and (ii) an interference fit fixed position in which it clamps said first cam body (302, 302') to said second cam body (304, 304') in a given position.

20. The adjustable cam system (218) of claim 19, wherein said clamping plate (306, 306') further comprises a locking arrangement (402) for locking said clamping plate (306, 306') in an operating position.

21. The adjustable cam system (218) of claim 20, wherein said locking arrangement (402) comprises a plurality of bores defined in said clamping plate (306, 306'), wherein said second cam body (304, 304^') comprises a complementary plurality of bores, and wherein said plurality of bores and said complementary plurality of bores are configured to accept a plurality of fasteners to secure said clamping plate (306, 306') in an operating position.

22. The adjustable cam system (218) of claim 21, wherein to enter said clamping plate (306, 306') in said sliding arrangement, said plurality of fasteners are partially engaged.

23. The adjustable cam system (218) of claim 21, wherein to enter said clamping plate (306, 306") in said sliding arrangement, said plurality of fasteners are fully disengaged.

24. The adjustable cam system (218) of claim 21, wherein to enter said clamping plate (306, 306^") in said interference fit fixed arrangement, said plurality of fasteners are substantially fully engaged.

25. The adjustable cam system (218) of claim 16, wherein said path of travel (310) is defined by a first groove (312a, 312a") defined in said first cam body (302, 302") and a second groove (312b, 312b") defined in said second cam body (304, 304^").

26. The adjustable cam system (218) of claim 25, wherein said first groove (312a, 312a") further defines a pre-opening break portion.

27. The adjustable cam system (218) of claim 16, wherein said first cam body (302, 302") further comprises a coupling arrangement (308, 308^") for coupling said first cam body (302, 302") to the first molding structure.

28. The adjustable cam system (218) of claim 16, further comprising an auxiliary locking structure (604).

29. The adjustable cam system (218) of claim 29, wherein said auxiliary locking structure (604) comprises a first plurality of bores (606) defined in said first cam body (302") and a second plurality of bores (608) defined in said second cam body (304"), a given one of said first plurality of bores (606) configured to cooperate with a given one of said plurality of second bores and a complementary fastener to provide auxiliary locking.

30. The adjustable cam system (218) of claim 28, wherein said auxiliary locking structure (604) comprises a first slot defined in said first cam body (302") and a second slot in said second cam body (304"), a given portion of said first slot configured to cooperate with a given portion of said second slot and a complementary fastener to provide auxiliary locking.

31. A mold assembly (202) incorporating the adjustable cam system (218) of claim 16.

32. A molding system (100) incorporating the mold assembly (202) of claim 31.

33. An interference fit interface (640) defined, in an operating position, between: a first linking structure (322, 322") associated with a first cam body (302, 302^") configured for attachment to a first molding structure;

a second linking structure (324, 324^") associated with a second cam body (304, 304') slidably linked to the first cam body (302, 302"); the first cam body (302, 302^") and the second cam body (304, 304") jointly defining a path of travel (310) for a cam follower (214);

a clamping plate (306, 306") configured in an interference fit fixed arrangement.

34. The interface of claim 33, wherein said interference fit interface (640) translates into a sliding interface when said clamping plate (306, 306^") is actuated into a sliding arrangement.

35. An interface defined between:

a first cam body (302, 302^") configured for attachment to a first molding structure;

a second cam body (304, 304") slidably linked to the first cam body (302, 302^"); the first cam body (302, 302^") and the second cam body (304, 304") jointly defining a path of travel (310) for a cam follower (214);

a clamping plate (306, 306^") selectively actuatable between a sliding arrangement and an interference fit locked arrangement, wherein

the interface comprises a sliding interface when said clamping plate (306, 306") is in said sliding arrangement;

the interface comprises an interfence fit fixed interface when said clamping plate (306, 306^") is in said interference fit fixed arrangement.

36. A method of adjusting an adjustable cam (216, 216"), the adjustable cam (216, 216") comprising a first cam body (302, 302^") and a second cam body (304, 304^") slidably linked to the first cam body (302, 302^") for jointly defining a path of travel (310) for a cam follower (214); a clamping plate (306, 306^") for selectively fixing position of the second cam body (304, 304") along the first cam body (302, 302^") in an interference fit, the method comprising:

entering the clamping plate (306, 306") into a sliding arrangement;

sliding the second cam body (304, 304") along the first cam body (302, 302") to a desired position; entering the clamping plate (306, 306^") into an interference fit fixed arrangement to fix the second cam body (304, 304^") and the first cam body (302, 302^") in the desired position.

37. The method of claim 36, the clamping plate (306, 306^") comprising a locking arrangement (402), wherein said entering the clamping plate (306, 306") into a sliding arrangement comprises adjusting said locking arrangement (402).

38. The method of claim 37, wherein said entering the clamping plate (306, 306^") into an interference fit fixed arrangement comprises securing said locking arrangement (402).

39. The method of claim 36, the clamping plate (306, 306^") comprising a plurality of bores, the second cam body (304, 304") comprising a complementary plurality of bores, the plurality of bores and the complementary plurality of bores being configured to accept a plurality of fasteners to secure the clamping plate (306, 306^") in an operating position, wherein said entering the clamping plate (306, 306^") into a sliding arrangement comprises at least partially disengaging the plurality of fasteners.

40. The method of claim 39, wherein said entering the clamping plate (306, 306^") into an interference fit fixed arrangement comprises securing said plurality of fasteners.

41. A method implemented in an adjustable cam system (218), the adjustable cam system (218) comprising an adjustable cam (216, 216^"), the adjustable cam (216, 216") comprising a first cam body (302, 302^") and a second cam body (304, 304") slidably linked to the first cam body (302, 302^") for jointly defining a path of travel (310) for a cam follower (214); a clamping plate (306, 306^") for selectively fixing position of the second cam body (304, 304") along the first cam body (302, 302^") in an interference fit, the method comprising:

at a first instance in time:

attaching the first cam body (302, 302") to a first molding structure;

sliding the second cam body (304, 304") along the first cam body (302, 302") to a first desired position;

securing the clamping plate (306, 306") to the second cam body (304, 304") to fix the second cam body (304, 304") in the first desired position;

at a second instance in time after said first instance in time: entering the clamping plate (306, 306^') into a sliding arrangement;

sliding the second cam body (304, 304') along the first cam body (302, 302') to a second desired position;

entering the clamping plate (306, 306^') into an interference fit fixed arrangement to fix the second cam body (304, 304') in the first desired position.

42. The method of claim 41, wherein at said first instance in time said securing is implemented before said sliding, and wherein said securing comprises:

attaching the clamping plate (306, 306^') to the second cam body (304, 304^');

entering the clamping plate (306, 306^') into a sliding arrangement;

and wherein the method further comprises, after said sliding, at said first instance in time, entering the clamping plate (306, 306^') into an interference fit fixed position.

43. A molding system (100) of a type having a movable platen (104), a fixed platen (102) and an injection unit (106), the molding system (100) comprising:

a first mold half associated with one of the movable platen (104) and the fixed platen (102);

a second mold half associated with the other one of the movable platen (104) and the fixed platen (102);

a stripper plate associated with one of the first mold half and the second mold half, the stripper plate comprising a plurality of split mold inserts (206);

an adjustable cam system (218) configured to control lateral movement of the plurality of split mold inserts (206),

a cam follower (214) configured for attachment to a connecting bar associated with the plurality of split mold inserts (206);

an adjustable cam (216, 216^') comprising: a first cam body (302, 302^') configured for attachment to one of the fixed platen (102) and the movable platen (104);

a second cam body (304, 304^') slidably engageable with the first cam body (302, 302"); the first cam body (302, 302") and the second cam body (304, 304") jointly defining a path of travel (310) for the cam follower (214);