Abstract:
In a single-row and expandable into a multi-row stretch blow molding method and apparatus, a robot having a universal gripper assembly is used to pick up molded preforms during the clamp opening stroke of a preform-molding unit and then transfer the preforms at variable time intervals to a conditioning, stretch blow molding and discharge unit, releases finished hollow articles and returns to a waiting position at the preform-molding unit independent of the preform-molding cycle. Simultaneously, component transfer devices pick up external components, i.e. labels, valves or handles during the stretch blow molding phase and release the components into the blow-mold cavities while the universal gripper assembly is in the waiting position. The universal gripper assembly can alternatively also be pivoted to pick up preforms from a lateral reheat unit to supplement the molded preform supply. A modular stack-blow-mold clamp assembly is equipped with a plurality of pivoting spacing means which open and close the blow-mold halves and align their respective parting lines to correspond with the center-row distances of the preform molds, conditioning and stretch blow means. Prior to the transfer of the molded preforms to a conditioning station, internal components, i.e. sleeves or liners can be inserted into the neck and body portion of the preforms. Further, a secondary robot with a gripper assembly can pick up pretreated preforms from the first set of blow molds and transfer them into one or several consecutive blow mold assemblies.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method for the preparation of preforms and hollow articles in single-row and multi-row preform and blow molds, respectively, and to an apparatus therefor. More particularly, the present invention relates to a method and apparatus, wherein a gripper assembly removes molded preforms either during a preform mold opening stroke or from a preform reheat unit, transfers the preforms through different processing phases, adding internal and external components during the transformation into hollow articles, and returns to a waiting position outside the preform molding or preform reheat unit. 
     2. Brief Description of the Prior Art 
     Heretofore, in conventional prior art molding machines, preforms are injected and transferred by their neck splits which are mounted beneath a horizontal transfer plate in an intermittent rotary motion of multi-station machines as described in U.S. Pat. Nos. 4,946,367 and 5,062,787. Apparatus described therein is dedicated to producing hollow articles in single-row molds. To increase production, the molder must acquire double-row rotary blow molding machines as described in U.S. Pat. Nos. 4,457,689, 4,941,816, and 5,062,787. Unfortunately, such machines evidence certain drawbacks, namely, the difficulty of mold interchangeability due to different swing radii and stack heights. In order to obviate such limitations, costly neck splits and neck split holders are required for each station. The rotary plates and the machine beds are required to be laid out for the higher clamping forces in the injection station. As a result, the increased inertia of the heavy construction and large swing radii of the transfer plates slows down the dead time of mold open index and mold close, thereby increasing the overall cycle times. Efforts to reduce dry cycle times have been made, as for example, by replacing the rotary tables through closed circuit conveyor devices as described in U.S. Pat. No. 4,895,509. However, once again, costly support jaws, mounted on slide guides, are required for each station linked together to transfer the preforms and containers through the forming phases in a rectilinear motion in equal distances and equal time intervals. In the rotary-type and chain-link-type method, all phases of preform molding, conditioning, stretch blowing, and discharging are also interdependent due to a common transfer movement. The larger the number and size of transfer components, the more machine component weight needs to be transferred, so resulting in slower dry cycles, and thus longer overall cycles. 
     The industry has recognized these limitations and has also recognized that containers can be conditioned, stretch blown, and discharged in a fraction of the time that it takes to mold the preforms. This discovery has led to a method and apparatus for injection stretch blow molding as described in U.S. Pat. No. 5,468,443, wherein a larger number of injection molding stations produce preforms to be conveyed to a lesser number of stretch blow molding stations. The drawback of this method and apparatus is that it requires neck split moving means for supporting and conveying neck splits adapted to hold-neck portions of each preform used to mold the hollow articles through all preform molding, conditioning, blow molding, and ejection stations. 
     Refinements of the aforementioned patent, U.S. Pat. No. 5,468,443, are described in U.S. Pat. Nos. 4,793,960, 5,753,279, and 5,744,176, wherein molded preforms are first inverted to be released onto carrier members of a transfer conveying system. The preform carrier members are spread to correspond to the blow mold center distances. The inverted preforms are then indexed through a reheating section to ascertain that the first batch of molded preforms enters the blow mold station with the same temperature profile as the following batches of simultaneously molded preforms. Once the preforms are stretch blown into final hollow articles, they are inverted again to release them in an upright position. The limitation of this technique resides in the fact that the molten preforms need to be inverted and to be put onto a multitude of neck-size-dependent carrier members. Spreading mechanisms are needed to widen the carrier members to the corresponding blow molding center distances and reheat ovens are needed for maintaining equal temperature profiles in the preforms which enter the blow molds consecutively. The bottom up stretch blow molding method is prone to preform-sagging and results in thinner bottoms and heavier shoulders in the hollow articles. A second inverted device is then needed to release the finished hollow articles in an upright position. The number of injection cavities vs. blow cavities remains at a fixed ratio which limits the processing flexibility for lighter-wall vs. heavier-wall containers. A further stretch blow molding concept is described in U.S. Pat. Nos. 4,372,910 and 4,470,796 in which molded preforms are picked up by two-row multiple gripper transfer devices, then inserted one row at a time into neck-size dependent collars of the respective closed circuit transportation system to be subsequently indexed to the conditioning, stretch blow and ejection stations. The drawback of this system is that the preforms have to be transferred in two steps, a first one to pick up the preforms and a second one to put the same onto neck-size dependent collars. The secondary transfer system is a common closed loop belt drive which does not allow any timing flexibility between the simultaneous conditioning and stretch blow phases to obtain maximum processing flexibility. As described in European Patent No. EP 0,768,166, the conditioning system is required to be twice as long as the stretch blow system to ascertain uniform temperature profiles for the first and second row preforms being introduced. The reduction of the number of blow cavities relative to the preform mold cavities is offset by the need of the number of additional transfer devices and neck-size-dependent collars. U.S. Pat. No. 4,197,073 teaches a method, wherein alternate sets of parisons are released into laterally diverging tracks before arriving at the blow-molding unit. Despite the reduction in the number of blow mold cavities, in the end, the number of blowing means is equal to the number of preform mold means. U.S. Pat. No. 4,209,290 teaches a method wherein blow molding cells are interposed between open injection mold halves and injection cores with their preforms descend into the blow molding cells to form finished bottles. The drawback of this method is that the preform-molding cycle is interrupted during the time it takes to blow-mold the bottles. 
     U.S. Pat. Nos. 5,731,014, 4,718,845, and 4,706,924 disclose a solution for gaining maximum utilization of molding machines by simply switching mold cavities than complete molds in both stack molds and single-face mold versions clamped between a fixed and movable machine platen. This solution works well in conventional injection molding machines. However, in stretch blow molding machines, secondary components such as conditioning rods, blow cores, stretch rods, and bottom plugs, etc. need to be introduced at a predetermined center distance row. European Patent No. EP 0,768,165-A2 teaches a method wherein mutually coupled mold plates, connected to a power transmission means, actuate through motion transferring means a double pair of mold halves. U.S. Pat. No. 4,941,816 describes a double row clamp molding machine, wherein each blow mold row is closed by lateral moving means. Subsequently, pan cake cylinders rise between the two rows and expand to apply the necessary clamp pressure against oppositely located clamping means. Both methods are limited to a fixed number of two rows of blow molds at a fixed machine-dependent center row distance. 
     U.S. Pat. Nos. 5,683,729, 5,110,282, 4,824,359, and 4,403,907 refer to cam-driven rotary pick and place assemblies, which simultaneously carry preforms and hollow articles through the blow molding and release phases. The limitation of such carrying means is that their rotary motion is interdependent, requires space modifying devices and, therefore, does not allow any timing and stroke distance flexibility between the various processing phases. U.S. Pat. No. 5,653,934 teaches a method wherein the linearly moving, article-engaging elements constitute an integral part of the mold, which do not allow any molding operation during the movement in and out of the molding machine. 
     A method for adding external components such as labels, handles, or valves to the preforms or hollow articles is described in U.S. Pat. Nos. 4,479,770 and 4,721,451, wherein components, such as labels, are picked up from dispensing heads by the label carrier shuttle and are moved rectilinearly into an open mold wherein they are released onto the mold cavity walls and returned in the same manner to the dispensing head position. The drawback of this method is that the normal blow molding cycle of rotary machines is interrupted to allow the time to introduce the labels into the open mold cavities. Typically, finished containers have to be evacuated first and new preforms need to be delayed from entering the open mold cavities. U.S. Pat. No. 4,983,348 partially overcomes this limitation by opening the upper mold half earlier and inserting labels into the open mold half while holding the previously blown and labeled work pieces or hollow articles in the lower mold half for the duration of the label transfer phase without increasing the overall machine cycle time. The drawback of this method is that only one mold half can receive labels and the distance between the work piece and movable blow mold halves needs to be sufficient to allow the dispensing mechanism to operate in between. 
     To add secondary components to preforms or hollow articles, U.S. Pat. No. 5,678,771 teaches a method wherein an insert is attached on the surface above the threads of a neck finish to maintain stability during and after hot-fill processing. The drawback of this method is that the non-oriented, amorphous neck finish portion beneath the attached reinforced insert can shrink and deform during the hot-fill phase. U.S. Pat. No. 4,988,472 teaches a method that prevents the afore-mentioned drawback. However, the insert is placed into a neckring portion of an open mold first and then over-molded with molten material, an operation that lengthens the overall cycle. 
     U.S. Pat. No. 4,847,129 teaches a method of molding a multi-layer neck-finish structure whereby the center layer consists of a high temperature polymer. 
     U.S. Pat. Nos. 5,651,933 and 3,939,239 teach a method wherein thermoformed sleeves are put on injection cores and are overmolded to obtain a multi-layer preform. The inner overmolded layer needs to be stiff enough to withstand the following injection pressures when injecting the outer layer. Thus, this method requires more costly inner barrier material and is more difficult to bond with the overmolded material. 
     U.S. Pat. No. 5,516,274 describes a movable blow mold clamp assembly permitting improved access for servicing. 
     SUMMARY OF THE INVENTION 
     1. Purposes of the Invention 
     It is an object of the present invention to mold preforms in single-row or multi-row preform mold cavities in variable-row spacings to give the molder maximum flexibility in meeting small and large production output requirements. Preform molds can be mounted perpendicular or in line relative to one or several plasticizers. 
     It is a further object of the invention to utilize a robot with a universal gripper assembly which picks up molded preforms during the preform mold opening stroke, transfers the same across a conditioning, and stretch blow unit to be converted into hollow articles, and then transfers them into an oriented discharge unit at variable time and stroke intervals before returning to a waiting position. 
     It is a further object of the invention to freely move the robot with the universal gripper assemblies in horizontal and vertical directions to position the preforms into the different processing units to condition, stretch-blow and discharge the same. 
     It is a further object of the invention to lay out the grippers at a multitude of center distances to enable the transfer of preforms and hollow articles with different size neck finishes and at various mold cavity center distances. 
     It is a further object of the invention to maximize the production capabilities through stack molds, wherein each blow mold half is opened and closed instantly by pivoting spacing platens which are aligned with the center row distances of the corresponding stretch rod, blow core, and bottom plug assemblies. The number of spacing-platen rows can be increased or decreased according to the desired number of blow mold rows. 
     It is a further object of the invention to vary the center row distances in the conditioning, stretch-blow, and bottom plug units according to the center rows of the preform molds. 
     It is yet a further object of the invention to turn the conditioning and stretch blow mold units to match the number of preform mold rows. 
     It is a further object of the invention to add additional blow mold units for multi-stage stretch-blow mold applications. 
     It is a further object of the invention to add a robot with a secondary universal gripper assembly to transfer pretreated hollow articles from the first blow mold unit into subsequent blow mold and discharge units. 
     It is a further object of the invention to add component transfer devices to pick up components during the blow-molding phase and to introduce these components into the open blow molds during the waiting phase. 
     It is a further object of the invention to insert components on the neck inside of preforms before the shrinkage phase of the molten material has been completed. 
     It is a further object of the invention to insert components on the inside of the preform walls prior to the conditioning and stretch-blow-molding phase. 
     It is a further object of the invention to pivot the gripper assembly to pick-up reheated preforms from a lateral reheat oven assembly. 
     It is a further object of the invention to mount the upper conditioning and blow-clamp assemblies onto linear bearings enabling to move said clamp assemblies laterally to facilitate mold and machine component mounting. 
     2. Brief Description of the Invention 
     In accordance with the present invention, molten material is introduced into single-row or multi-row preform mold cavities. Upon completion of the solidification phase, the upper mold half is raised together with the injection cores. Immediately thereafter, during the mold-opening stroke, a robot with a universal gripper assembly enters between the movable mold halves and follows their movement to pick up the molded preforms on-the-fly. If the preform mold construction is such that the neck splits lift the preforms out of the preform mold cavities, the preforms are picked up below their transfer bead. If the preform mold construction is such that the neck splits stay with the preform cavities and are lifted out by the injection cores, the robot with the universal gripper assembly may pick up the preforms by the neck finish, as the injection cores are being fully retracted. Immediately after the robot with the universal gripper assembly transfers the preforms to the conditioning unit, the preform mold is closed again to mold the next set of preforms. The robot with the universal gripper assembly holds the preforms in the conditioning unit just long enough for the internal touch rods and external heater pots to monitor the temperature profile in the preforms. Next, the robot with the universal gripper assembly brings the conditioned preforms into the blow molds, wherein, after the bottom plugs have been raised and the molds have been closed, the blow cores and stretch rods descend to enter the preforms at their open ends, low and high pressure blow air comes on and forms finished hollow articles. Immediately upon completion of the stretch blow cycle, the blow cores and stretch rods lift out of the blow molds, the blow molds are opened, and the robot with the universal gripper assembly lifts the finished hollow articles out of the blow mold cavities to transfer the same into the oriented discharge unit. The robot with the now empty universal gripper assembly returns to a waiting position at the preform molding station. Due to the fast cooling nature of certain materials, such as PET or PEN, among others, the time periods necessary for conditioning, stretch-blowing, cooling, and oriented discharging, as well as for the short and quick transfer strokes of the robot with its light-weight universal gripper assembly and with its reduced inertia happen within a fraction it takes to mold the preforms. 
     In addition to the preform supply from the molding unit, outsourced preforms from an adjacent reheat unit can be supplemented. During this intermediate phase, the universal gripper assembly pivots and picks up reheated preforms from said reheat unit and transfers them the same way in a short linear movement through the conditioning, stretch blow, and oriented discharge phases. 
     In view of the freely programmable and time-independent movement of the robot with the universal gripper assembly, following component transfer devices can be added. During the stretch blow phase, these transfer devices pick up components such as labels, handles, valves, etc. When the robot with the universal gripper assembly has returned to the waiting position, the components are released into each blow mold half, all without any increase in the total cycle time. 
     The above described process shows that the number of blowing means is equal to the number of preform means. Therefore, to further boost production and to gain maximum utilization of the preform-molding unit, stack-blow molds are installed to meet the production of a larger number of preform cavities. The blow-mold clamp requirements are virtually the same with single-row or multi-row blow mold assemblies. A selectable number of pivoting spacer platens, located between the blow mold rows, provide instant mold opening and closing as well as parting-line alignment with the entering bottom plugs, blow core and stretch-rod assemblies mounted in a stationary position. A synchronized movement of the enveloping blow-mold clamping means provides the final blow-mold clamping pressure. 
     The injection core, conditioning and stretch-blow rods are held onto individual clamp bars. The clamp bars are bolted individually onto the machine clamp platens according to the center distance rows of the preform and blow-mold cavities. The neck splits or stripper plates and the blow cores are also mounted on individual clamp bars. These clamp bars are bolted individually onto frame-type machine clamp platens within the respective units. This flexibility in varying the center distance rows permits the mounting of existing molds, adding or deleting mold cavity rows, thereby increasing or decreasing mold opening daylights for the production of larger and smaller hollow articles, respectively. 
     The injection, conditioning, stretch-blow and oriented discharge units can be turned based on the preform mold design to minimize the number of universal gripper assemblies. 
     Certain molten materials such as PC or PP, heavy-wall returnable PET bottles, or heat-set PET bottles require stepped processing treatments to achieve specifications. In this case, additional blow-mold units and a secondary robot with a universal gripper assembly are installed. In this processing mode, once the principal robot with the universal gripper assembly has transferred the preforms into the first blow-mold assembly, it returns to the waiting position at the preform-molding machine. A secondary robot with a universal gripper assembly picks up the pretreated preforms and transfers them directly to one or several subsequent blow mold units and finally to an oriented discharge unit. 
     Hollow articles tend to deform in non-stretch-blow-molded areas such as the neck finishes during hot-fill operation. A unit capable of transferring internal components into preforms may be installed right after the preform-molding unit. An internal component transfer device picks up heat-stable sleeves from a sorting conveyor. The robot with the universal gripper assembly picks up the preforms from the preform-molding unit at elevated neck temperatures, thus before the shrinkage phase has been completed, and transfers them to an internal component transfer unit, wherein the heat-stable sleeves are released into the open-ended preforms. The sleeve-reinforced preforms are then transferred to a conditioning unit, wherein the cooling neck finishes shrink tightly onto the heat-stable sleeves. After passing through one or several stretch-blow units, neck heat-stable hollow articles are released into an oriented discharge unit. 
     To enhance the barrier properties of hollow articles, a thin inner liner of high-barrier material can be inserted the same way into the preforms by the internal component transfer device prior to transferring the same into a conditioning and stretch-blow unit. 
     The above-described stretch-blow molding method and apparatus provides the molder with maximum production flexibility by forming hollow articles in either single-row or multi-row blow-mold assemblies as well as processing versatility in adding additional stretch-blow mold units and introducing external and internal components to the hollow articles. The open architecture of the individual processing units permits the installation of molds from different machine designs and requires one set of neck splits in the preform mold only. The completely separate preform molding unit from all other processing units and preform pick-up “on-the-fly” allows the quickest mold opening and closing of the preform mold clamp. All the downstream phases described above happen within the preform-mold filling, forming and cooling phases. Thus, the preform molding phase and the rapid mold opening, preform take-out and mold closing phase constitutes the total processing cycle. 
     Adding an additional reheat unit further increases the output capabilities of the stretch blow-molding machine to meet seasonal market demands. 
     Prior art for robotic gripper assemblies requires removal of preforms from a molding unit or finished hollow articles from an ejection or blow-mold station of a stretch-blow-molding machine when in a static position and placing them onto conveying means. The improvement described herein involves the use of a robot with a universal gripper assembly to pick up molded preforms from a preform molding unit during the mold-opening stroke or from a reheat oven and transferring them at freely programmable intervals to a multitude of individual processing units performing multiple functions, such as conditioning, stretch-blowing, adding internal or external components, or hand-over pre-treated hollow articles to subsequent stretch-blow units prior to final release of the finished hollow articles. In this capacity, the robot with the universal gripper assembly replaces the use of heavy rotary transfer plates carrying neck splits for each station, or circulatory carriers with neck-mold moving pieces, or carriages with neck-size-dependent support jaws, each being linked together in a closed circuit. 
     Prior art for multi-row blow-mold clamps requires that each blow mold row is first closed by external moving means. Subsequently, a pancake cylinder assembly is raised in between the rows which are expanded to apply the necessary clamp pressure against opposite clamping cylinders on each end, or a power transmission means is used to actuate, through motion-transferring means, a double pair of mold halves only. 
     In accordance with the present invention, a multitude of pivoting spacing platens is mounted to instantly create a blow mold row opening and closing action within selected center distance rows. Synchronized peripheral clamping means are then used to apply the necessary closing force. A further refinement involves the flexibility of adding or deleting spacing platens depending on the desired number of blow-mold rows. The benefits to the molder are to adapt production outputs to market demands within the same stack-mold clamping means. The higher output rate capabilities of stack-blow-mold assemblies make in-line hollow article filling and pasteurization economical with the one-step process. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood by reference to the following detailed description taken in conjunction with the accompanying drawing wherein: 
     FIG. 1 is a side view of a stretch-blow molding method and apparatus showing from right to left a plasticizer, a preform molding unit, a conditioning unit, a robot with freely programmable universal gripper assembly in a waiting position, a component-transfer device assembly, a stretch blow mold unit, an oriented discharge unit beneath front and back component dispensing cartridges; 
     FIG. 2 is a front view of a stretch-blow molding unit with clamp cylinders, a stretch rod assembly, a blow core assembly mounted on linear bearings, a robot with a universal gripper assembly and drive, a blow-mold clamp assembly with pivoting spacing platens and drive means as well as bottom plug moving means; 
     FIG. 3 is a back view of a stretch-blow molding unit and component-dispensing assembly showing from top to bottom the blow-clamp cylinders, the component dispensing cartridges, a robot with the component-transfer device assembly in a component pick-up position, a universal gripper assembly holding the hollow articles in the blow-mold assembly, the pivoting spacing platen with drive means, and the bottom-plug moving means; 
     FIGS. 4-11 show a schematic sequence of a robot with a universal gripper assembly, followed by a transfer component device assembly in conjunction with a stretch-blow molding sequence; 
     FIG. 4 shows a schematic side view of a robot with a universal gripper assembly picking up a molded preform and a transfer component device assembly in a stand-by position; 
     FIG. 5 shows a schematic top view of a stretch-blow molding sequence showing from right to left a plasticizer, a preform-molding unit, a conditioning unit, a stretch blow molding unit in a closed position with external components applied, and an oriented discharge unit; 
     FIG. 6 shows a schematic side view of a robot with a universal gripper assembly holding a hollow article with external components applied as well as a transfer component device assembly in an external component pick-up position; 
     FIG. 7 shows a schematic side view of a robot with a universal gripper assembly in a finished hollow article discharge position and a transfer component device assembly holding external components on a front and back side; 
     FIG. 8 is a schematic top view of a stretch-blow molding sequence showing from right to left a plasticizer, a preform molding unit, a conditioning unit, a stretch-blow molding unit in an open position ready to receive external components by a transfer component device assembly, a universal gripper assembly in a waiting position, and an oriented discharge unit; 
     FIG. 9 shows a schematic side view of a robot with a universal gripper assembly in a waiting position and a transfer component device assembly in an external component-release position; 
     FIG. 10 shows a schematic top view of a stretch-blow molding sequence showing from right to left: a plasticizer, a preform molding unit, a conditioning unit, a stretch-blow molding unit in an open position holding external components, such as labels in each mold half, a transfer component device assembly in a component-pick-up position and a universal gripper assembly in a stretch-blow position, front and back component-dispensing cartridges, above an oriented discharge unit; 
     FIG. 11 shows a schematic side view of a robot with a universal gripper assembly ready to pick up a preform and a component transfer device assembly in an external component stand-by position; 
     FIG. 12 is a top view of a single-row stretch-blow molding apparatus showing from right to left a plasticizer, a preform-molding unit, a conditioning unit, a stretch-blow unit and stack blow mold clamp assembly with pivoting spacing platens, and an oriented discharge unit with a universal gripper assembly; 
     FIG. 13 is a top view of a single-row stretch-blow mold apparatus, as shown in FIG. 12, in which the plasticizer, preform-molding unit, conditioning unit, stretch-blow unit, and oriented discharge unit have been turned to minimize the number of universal gripper assemblies mounted onto the robot; 
     FIG. 14 shows a schematic movement of a universal gripper assembly as from right to left starting at a take-out position of a preform molding unit, traversing to a conditioning unit, descending onto a stretch-blow unit, retracting to an oriented discharge unit, returning to a waiting position, and ascending back into an opening preform molding unit; 
     FIG. 15 is a top view of a single-row stretch-blow molding apparatus with a robot and a pivoting universal gripper assembly picking up preforms from a reheat unit and transferring the same through a conditioning and stretch-blow unit into an oriented discharge unit; 
     FIG. 16 shows a schematic side view sequence of a robot with a universal gripper assembly in a pivoted position, picking up reheated preforms from a reheat unit, pivoting back to its basic position to bring them to a conditioning unit, releasing them into a stretch-blow unit for transforming into hollow articles, retracting them toward an oriented discharge unit, and returning to a reheat unit; 
     FIG. 17 is a side view of a single-row stretch blow molding apparatus showing from right to left a plasticizer, a preform molding unit, a robot with a universal gripper assembly in a pivoted position, a reheat unit behind, a conditioning unit, a stretch-blow unit, and an oriented discharge unit; 
     FIG. 18 is a top view of a single-row stretch blow molding apparatus as shown in FIG. 12, wherein a robot together with the universal gripper assembly indexes along a lateral guide rail; 
     FIG. 19 is a top view of a multi-row stretch blow molding apparatus wherein a robot together with a universal gripper assembly indexes along a lateral guide rail; 
     FIG. 20 shows a back view of a schematic movement of a laterally indexing robot with a universal gripper assembly from right to left, starting at a take-out position in the preform-molding unit, moving to a conditioning unit, descending onto a stretch-blow unit, retracting to an oriented discharge unit, returning to a waiting position, and ascending back to an opening preform-molding unit; 
     FIG. 21 is a side view of a multi-row stretch blow molding apparatus showing from right to left a plasticizer, a preform-molding unit, a conditioning unit, a stretch blow unit, an oriented discharge unit, and a robot with universal gripper assembly; 
     FIG. 22 is a top view of a multi-row stretch-blow molding apparatus with individual clamping means showing from right to left a plasticizer, an injection-core holding platen, and rows of neck-ring holding bars mounted onto a frame-type clamp platen beneath, a conditioning rod-holding platen and rows of conditioning rod-holding bars mounted beneath, a stretch-rod holding platen, and rows of blow-core holding bars mounted onto a frame-type clamp platen beneath, an oriented discharge unit beneath a robot with a universal gripper assembly, and a drive mounted onto a traversing beam rail frame of the robot; 
     FIG. 23 is a stack-blow mold assembly section in a closed position with the spacing platens assembly in an extended position; 
     FIG. 24 is a stack blow mold assembly section in an open position with the spacing platens assembly in a retracted position showing the rows of bottom plugs, a clamp cylinder, and a clamp-platens synchronizing gear mechanism; 
     FIG. 25 is a top view of a multi-row stretch blow molding apparatus showing from right to left the plasticizers, a preform-molding unit, a conditioning unit, a stretch blow unit with stack-mold assembly and spacing platens, an oriented discharge unit with a robot and universal gripper assembly; 
     FIG. 26 shows a schematic movement of a universal gripper assembly from right to left starting at a take-out position of a preform-molding unit, traversing to a conditioning unit, descending onto a stretch-blow unit, retracting to an oriented discharge unit, returning to a waiting position, and ascending back into an opening preform-molding unit; 
     FIG. 27 is a sequential view of a molded preform with internal component preparation, an internal component pick-up and inserting device, a molded preform with an inserted internal component and a finished hollow article with an inserted internal component; 
     FIG. 27 a  is a sequential view of the molded preform as shown in FIG. 27 wherein an inner liner has been inserted into the preform and a multi-layer hollow article has been formed; 
     FIG. 28 is a side view of a multi-row stretch-blow molding apparatus showing from right to left: a plasticizer, a preform molding unit, an internal component sorting and conveying unit and an internal component pick-up and inserting unit, a conditioning unit, a stretch-blow unit, an oriented discharge unit, and a robot with a universal gripper assembly; 
     FIG. 29 shows a schematic top view of a multi-row stretch blow molding apparatus as shown in principle in FIG. 25 from right to left: the plasticizers, a preform molding unit, an internal component-indexing sorting conveyor unit, a conditioning unit, a stretch-blow molding unit, a robot with universal gripper assembly, as well as a secondary stretch-blow molding unit, a secondary robot with a secondary universal gripper assembly above an oriented discharge unit; 
     FIG. 30 shows a schematic side view sequence of a principal and a secondary robot with universal gripper assemblies from right to left: the principal robot with the universal gripper assembly picks up preforms (not shown) from the preform molding unit, indexes to an adjacent internal component-indexing sorting conveyor unit, travels to a conditioning unit, releases the preforms into a stretch-blow molding unit, returns to a waiting position, and then ascends again into an opening preform mold assembly. In the meantime, a secondary robot with a universal gripper assembly picks up the pretreated preforms (not shown) and transfers the same into a subsequent stretch-blow molding unit and oriented discharge unit. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with the present invention there is provided a single-row and multi-row stretch blow molding method and apparatus, wherein a robot with a universal gripper assembly picks up molten preforms from a preform-molding unit during the mold-opening stroke and guides them through the steps of conditioning, stretch-blow molding, oriented discharging, and then returns to a waiting position at the preform-molding unit. The freely programmable time and stroke intervals of the robot with the universal gripper assembly to complete the stretch blow molding process are substantially faster than the preform molding process and thus allows the pick-up of additional preforms from a reheat unit and the introduction of components to the external and internal walls of the hollow articles without increasing the overall cycle. A modular stack-blow-mold assembly provides the opportunity for increased production in the same blow molding apparatus. A further set of robots with universal gripper assemblies and blow mold units provide the opportunity to treat the preforms in multi-stages before being released as hollow articles into an oriented discharge unit. 
     With reference now more particularly to the drawings, FIG. 1 is a side view of a stretch-blow molding method and apparatus, showing from right to left a plasticizer  10 , a preform-molding unit  12  with a preform-mold-cavity assembly  26  in a closed position mounted on a base frame  20 , wherein the neck splits  18  remain in sliding connection  87  with the preform-mold-cavity assembly  26  upon raising the frame-type platen  16  holding the ejector bar  88  by the vertical clamp cylinders  14  and  15 . Tie bars  19  connect the base platen  20  with the upper clamp platen  13 . A movable intermediary clamp-platen housing  21  is connected to the frame-type clamp platen  16 . A central clamp cylinder  22  is mounted onto the intermediary clamp-platen housing  21  which moves the injection core-holding platen  23  with the injection-core-mounting bar  24  and injection cores  25 . During the opening movement of the frame-type clamp platen  16 , a universal gripper assembly  27 , mounted onto a robot  28 , starts entering the opening clamp area and follows its upward movement. As the central clamp cylinder  22  moves the injection cores  25  upwards beyond the ejector bar  88 , the universal gripper assembly  27  grasps the freeing molded preforms  89  and transfers them to a conditioning unit  31  and from there into a stretch-blow-molding unit  40  to form the hollow articles  86  which are subsequently released in an oriented discharge unit  58 , and returns to a waiting position  81 . 
     A following transfer component device assembly  90 , which has picked up external components  92  from front and back component dispensing cartridges  91  during a previous stretch-blow molding phase, places the same external components  92  into the open blow molds  41  in its component release position  94  during the waiting phase of the universal gripper assembly  27 . 
     FIG. 2 shows a front view of a stretch blow molding unit  40 , wherein the upper portion  60  with the upper moving-means platen  51  on which are mounted the vertical stretch-blow moving means  50  and  75  that drive the blow cores  47  which are mounted on a frame-type platen  49  with blow-core holding bars  48  and intermediary stretch-rod clamp-platen housing  52  having central stretch-rod moving means  57  mounted onto the frame-type blow-core clamp platen  49  holding the stretch rods  56 , which are mounted on a stretch-rod holding platen  54  with stretch-rod holding bars  55  which ride on linear bearings  59  enabling the upper portion to slide out of its operating position to facilitate the mold change-over procedure. A track rail  30  guides a traversing beam  61 , which is monitored by a drive  62 . Traversing beam  61  carries robot  28  with the vertical gripper moving means  29  and the gripper opening and closing means  63  of the universal gripper assembly  27 . A stretch-blow mold assembly  41  is located beneath the upper portion  60  of the stretch blow unit  40  mounted between blow mold clamp platens  67  attached to tie bars  66 . Pivoting spacing platens  44  monitored by rotating means  45  and drive gears  64  are mounted in between the blow mold-cavity assembly  41 , onto a support frame  65  and upper center cross bars  70 . Bottom-plug rows  42  are monitored by moving means  43  mounted onto a support frame  65 . 
     FIG. 3 is a back view of a stretch-blow mold unit  40  as described in FIG. 2. A frame assembly  93  in front of the stretch blow unit  40  holds the front and back component dispensing cartridges  91 . A following transfer component device assembly  90 , mounted on a traversing beam  61 , is in its component pick-up position  95  while the universal gripper assembly  27 , the blow cores  47 , and stretch rods  56  are in a stretch-blow molding position  97 . 
     FIGS. 4 to  11  show a schematic sequence of a robot  28  with a universal gripper assembly  27  followed by a transfer component device assembly  90  in conjunction with a stretch-blow molding sequence. 
     FIG. 4 shows a schematic side view of a robot  28  with a universal gripper assembly  27  picking up a molded preform  89  and a transfer component device assembly  90  in a stand-by position  98 . 
     FIG. 5 is a schematic top view of a stretch blow molding sequence showing from right to left a plasticizer  10 , a preform molding unit  12 , a conditioning unit  31 , a stretch-blow molding unit  40 , a gripper assembly (not shown), wherein external components  92  are being applied in the closed stretch-blow-mold assembly  83  onto finished hollow articles  86  and a finished hollow article discharge unit  58 . 
     FIG. 6 shows a schematic side view of a robot  28  with a universal gripper assembly  27  in a hollow article stretch blow molding position  97  and a finished hollow article  86  with external components  92  applied as well as a transfer component device assembly  90  in an external component pick-up position  95 . 
     FIG. 7 shows a schematic side view of a robot  28  with a universal gripper assembly  27  in a finished hollow article discharge position  80  and a transfer component device assembly  90  in a stand-by position  98  holding external components  92  on the front and back side. 
     FIG. 8 is a schematic top view of a stretch blow molding sequence showing from right to left a plasticizer  10 , a preform molding unit  12 , a conditioning unit  31 , a stretch blow molding unit  40 , wherein in an open stretch blow mold assembly  83  external components  92  are going to be placed by a transfer component device assembly  90  in a component release position  94  and a universal gripper assembly  27  mounted on a robot  28  in a gripper waiting position  81  and a finished hollow article discharge unit  58 . 
     FIG. 9 shows a schematic side view of a robot  28  with a universal gripper assembly  27  in a waiting position  81  and a transfer component device assembly  90  holding on the front and back side external components  92  in a component release position  94 . 
     FIG. 10 is a schematic top view of a stretch blow molding sequence showing from right to left a plasticizer  10 , a preform molding unit  12 , a conditioning unit  31 , a stretch-blow molding unit  40 , wherein in the open stretch-blow mold assembly  83  external components  92  had been placed during the gripper-waiting phase, and a universal gripper assembly  27  mounted on a robot  28  holds molded preforms  89  placed between the closing stretch blow mold assembly  83  in a stretch blow molding position  97  while a transfer component device assembly  90  located above the oriented discharge unit  58  picks up external components  92  from the front and back component dispensing cartridges  91  in its component pick-up position  95 . 
     FIG. 11 shows a schematic side view of a robot  28  with a universal gripper assembly  27  ready to pick up preforms (not shown) from a preform molding unit (not shown) and a component transfer device assembly  90  in a component stand-by position  98  holding front and back components  92 . 
     FIG. 12 is a top view of a single-row stretch-blow mold apparatus showing from right to left: a plasticizer  10 , a preform mold cavity assembly  26 , in a preform molding unit  12 , a set of heat pots  36  in a conditioning unit  31 , a single-row blow-mold assembly  83  with pivoting spacing platens  44  and a stack blow-mold clamp assembly  46  in a stretch-blow molding unit  40 , positioned in line to a traversing robot  28  with a universal gripper assembly  27  mounted onto a traversing beam  61  and its vertical upper moving means  29  also attached to a traversing beam  61  releasing finished hollow articles onto a lateral oriented discharge unit  58 . A multitude of cut-outs in the gripper arms  99  at a multitude of mold cavity center distances allow transfer of preforms and hollow articles with different neck finish sizes and center distances. 
     FIG. 13 is a top view of a single-row stretch-blow mold apparatus as shown in FIG. 12 in which the plasticizer  10 , the preform mold unit  12  with a preform-mold-cavity assembly  26 , the conditioning unit  31  with a set of heat pots  36 , the stretch blow molding unit  40  with a single-row blow mold assembly  83  with pivoting spacing platens  44 , and blow mold clamp assembly  46  have been turned perpendicular to a traversing robot  28  with a single-row universal gripper assembly  27  and vertical moving means  29 , located on the traversing beam  61 , releasing finished hollow articles onto an in-line oriented discharge unit. 
     FIG. 14 shows a schematic movement of a traversing robot  28  with a universal gripper assembly  27  for a stretch-blow molding method and apparatus, starting from right to left at a molded-preform take-out position  77 , traversing to a preform-conditioning position  78 , descending onto a preform-stretch-blow molding position  79  where the preforms are stretch-blown into hollow articles, retracting to a finished hollow article oriented discharge position  80 , returning to a gripper-waiting position  81 , and ascending back towards a preform-pick-up position  82 . 
     FIG. 15 is a top view of a single-row stretch blow molding apparatus as described in FIG. 12 except between the preform mold unit  12  with its preform mold cavity assembly  26  and the conditioning unit  31  is installed a preform reheat unit  100 . The universal gripper assembly  27  has been pivoted into a preform take-out position  77  by gripper rotating means  101 , connected to the robot  28  to pick up reheated preforms  89  to be transferred through the conditioning unit  31 , the stretch-blow mold unit  40  where they are transformed into hollow articles and released into the oriented discharge unit  58 . 
     FIG. 16 shows a schematic sequence from right to left of a robot  28  with a universal gripper assembly  27  pivoted by the gripper rotating means  101  into a preform take-out position  77 , then being returned by same gripper rotating means  101  into a basic traversing mode to enter a preform conditioning position  78  descending onto a preform stretch blow molding position  79 , where the preforms are being stretch-blown into hollow articles, retracting to a finished hollow article oriented discharge position  80 , returning to a universal gripper preform pick-up position  82 . 
     FIG. 17 is a side view of a single-row stretch blow molding apparatus as described in FIG. 1 with a plasticizer  10  and a preform molding unit  12 . A robot  28  with gripper moving means  29  is equipped with gripper rotating means  101  that pivot a universal gripper assembly  27  into a preform take-out position  77  to pick up preforms  89  from a lateral preform reheat unit  100  and returns to its basic position to guide the preforms through a conditioning unit  31  and a stretch blow unit  40  to be stretch-blown into hollow articles  86  which are released in an oriented discharge unit  58 . 
     FIG. 18 is a top view of a single-row stretch-blow molding apparatus as shown in FIG. 12, wherein a robot  84  indexes sideways together with a universal gripper assembly  27  along a lateral guide rail  85  to pick up molded preforms from an opening preform-mold-cavity assembly  26  in the preform-molding unit  12 , indexes the same into a conditioning unit  31 , descends into a single-row blow mold cavity assembly  83  in a stretch-blow molding unit  40 , where preforms are stretch-blown into hollow articles, and retracts into an oriented discharge unit  58  to release finished hollow articles  86 . 
     FIG. 19 is a top view of a multi-row stretch-blow molding apparatus as shown in FIG. 12, wherein a robot  84  indexes sideways together with a universal gripper assembly  27  along a lateral guide rail  85  to pick up molded preforms from an opening preform mold cavity assembly  26  in a preform molding unit  12 , indexes the same into a conditioning unit  31 , descends into a multi-row stack-blow mold cavity assembly  41  in a stretch-blow molding unit  40 , wherein the preforms are stretch-blown into hollow articles, and retracts into an oriented discharge unit  58  to release the finished hollow articles  86 . 
     FIG. 20 shows a back view of a schematic movement of a laterally indexing robot  84  indexing sideways with a universal gripper assembly  27  starting from right to left, at a preform-take-out position  77 , indexing to a preform-conditioning position  78 , descending onto a preform-stretch-blow-molding position  79 , where the preforms are stretch-blown into hollow articles, retracting to a finished-hollow-article-discharge position  80 , returning to a gripper-waiting position  81 , and ascending back towards a preform-pick-up position  82 . 
     FIG. 21 is a side view of a multi-row stretch-blow molding method and apparatus showing from right to left a plasticizer  10 , a preform-molding unit  12  consisting of an upper clamp platen  13  with vertical clamp cylinders  14  and  15  connected to a frame-type clamp platen  16  holding the neck split mounting bars  17  and neck splits  18 . The frame-type clamp platen  16  slides up and down on tie bars  19  which are connected to the base platen  20  and the upper clamp platen  13 . An intermediary clamp platen housing  21  is connected to the frame-type clamp platen  16 . A central clamp cylinder  22  is mounted onto the intermediary clamp platen housing  21  which moves the injection core holding platen  23  with the injection core mounting bars  24  and injection cores  25 . A preform mold cavity assembly  26  is mounted onto the base frame  20 . The preform-molding cycle starts when the frame-type clamp platen  16  with the neck-split mounting bars  17  and neck splits  18  have been lowered onto the mold cavity assembly  26  by the vertical clamp cylinders  14  and  15 , and the injection cores  25  have entered the preform mold cavity assembly  26 . 
     Upon completion of the preform molding phase, both the frame-type platen  16  and the intermediary clamp platen housing  21  are raised together by the vertical clamp cylinders  14  and  15 . A universal gripper assembly  27 , mounted onto a robot  28  with a vertical moving means  29 , slides on track rails  30  to enter between the opening preform-molding area of the fixed preform mold cavity assembly  26  and neck splits  18 , and follows their upward movement. The central clamp cylinder  22  lifts the injection cores  25  out of the molded preforms (not shown). The moment neck splits  18  have been opened by a spreading device (not shown), the universal gripper assembly  27  picks up the preforms (not shown) and guides them to the conditioning unit  31 . The preform-mold cavity assembly  26  is closed again to mold a new set of preforms. The conditioning rods  32  held by individual mounting bars  9  and mounted upon the base plate  33 , connected to a central conditioning rod clamp cylinder  34  and guide rods  35 , descend into the preforms (not shown). A set of heat pots  36  are raised around the preforms (not shown) by central raising means  37  and aligned by guide rods  38  mounted on a base unit  39 . Upon completion of the conditioning phase, the conditioning rods  32  and the heat pots  36  retract. The universal gripper assembly  27  indexes the preforms into the stretch-blow-molding unit  40  and lowers them into stretch-blow molds  41  with the gripper moving means  29 . Bottom plugs  42  are raised by bottom plug moving means  43 . Rotating means  45  pivot spacing platens  44  to close the blow-mold halves  41 . The blow-mold clamp assembly  46  with synchronizer (not shown) generates the final clamp closing pressure. Simultaneously, blow cores  47  held by blow core holding bars  48 , mounted onto a frame-type blow-core clamp platen  49 , are lowered onto the preforms (not shown), held in the closed blow-mold cavities  41  by vertical moving means  50  and  75 , mounted onto the upper moving means platen  51 . An intermediary stretch-rod clamp-platen housing  52 , mounted onto the frame-type blow-core clamp platen  49  follows the blow-core movement. Central stretch-rod moving means  57 , mounted onto the intermediary stretch-rod clamp-platen housing  52 , connected to the stretch-rod holding platen  54 , with the stretch-rod mounting bars  55  holding stretch rods  56  and moves stretch rods  56  into the preforms (not shown). Upon completion of the stretch-blow phase, vertical stretch-blow moving means  50  and  75  as well as stretch-rod moving means  57  retract to their upper positions, the universal gripper assembly  27  is raised by the gripper moving means  29  and retracts the finished hollow articles  86  to an oriented discharge unit  58 . 
     FIG. 22 shows a top view of a stretch-blow molding method and apparatus consisting of plasticizer  10 , preform molding unit  12 , conditioning unit  31 , stretch-blow molding unit  40 , all equipped with upper moving-means platens  13 ,  8 , and  51  holding vertical clamping means  14 ,  15 ,  34 ,  50 , and  75 , respectively. Beneath are located the intermediary clamp platen housings  21  and  52  holding central clamp cylinders  22  and  57 . Central clamp cylinders  22 ,  34 , and  57  are connected to holding platens  23 ,  33 , and  54 , respectively, under which are held in place on individual mounting bars  24 ,  9 , and  55  the injection cores  25 , the conditioning rods  32 , and the stretch rods  56 , respectively. Beneath the holding platens  23  and  54  are located the individual mounting bars  17  and  48  to hold the neck splits  18 , and blow cores  48  onto frame-type clamp platens  16  and  49 , respectively, with elongated mounting holes  74  which permit variations in the center row distances according to the preform mold cavity center distances. Mounting bars  9  for the conditioning rods are bolted in elongated slots  74  onto the holding platen  33 . The top view further shows a universal gripper assembly  27  with opening and closing means  63  mounted onto a robot  28  monitored by a drive  62  and gripper moving means  29  and an oriented discharge unit  58  beneath. A multitude of cut-outs in the gripper arms  99  at a multitude of mold cavity center distances allows to transfer preforms and finished hollow articles with different neck finish sizes and center distances. 
     FIG. 23 is a top view of a multi-row stack-blow mold cavity assembly  41  in a closed position with pivoting spacing platens  44  in an extended position driven by rotating means  45 , wherein the stretch-blow mold mounting platens  68  are directly attached and extended by a hinge mechanism  69 . Center-cross bars  70 , attached to blow-mold tie bars  66 , serve as a fixed center pivot point for the center axis  71  of the pivoting spacing platens  44 . Synchronized blow-mold clamp platens  67  generate the necessary clamp closing force. 
     FIG. 24 shows a multi-row stack-blow mold cavity assembly  41  in an open position with pivoting spacing platens  44  and hinge mechanism  69  in a retracted position. Bottom plug rows  72  and bottom-plug-moving means  43  are shown between the open multi-row stack blow mold halves  41 . Blow mold clamp cylinder  46 , monitored by a clamp platen synchronizer assembly  73 , opens outer blow-mold clamp platens  67  attached to blow-mold tie bars  66 . 
     FIG. 25 shows a top view of a multi-row stretch-blow molding apparatus with, from right to left: plasticizers  10  and  11 , a multitude of preform-mold-cavity assemblies  26  and  76  in preform molding unit  12 , a set of heat pots  36  in conditioning unit  31 , multi-row stack blow mold  41  in a stretch-blow unit  40  with pivoting spacing platens  44  and blow-mold clamp assembly  46  turned perpendicular two the traversing robot movement, a universal gripper assembly  27  mounted onto a robot  28  with gripper-assembly moving means  29  located on a traversing beam  61  and an oriented discharge unit  58  beneath. 
     FIG. 26 shows a schematic movement of a robot  28  with a universal gripper assembly  27 , starting from right to left at a molded-preform take-out position  77 , traversing to a preform conditioning position  78 , descending onto a preform-stretch-blow molding position  79 , where the preforms are stretch-blown into hollow articles, retracting to a finished hollow article oriented discharge position  80 , returning to a gripper waiting position  81 , and ascending back towards a preform pick-up position  82 . 
     FIG. 27 is a sequential side view from right to left of a molded preform  89  with a neck section  108  at an elevated temperature to receive an internal component before the shrinkage phase has been completed. An internal component pick-up and inserting device  109  having positioned an internal component  103  in the neck section  108  of a molded preform  89  while still at an elevated temperature. An internal component  103  is shrunk into the neck section  108  of a stretch-blown hollow article  86  during the conditioning, the stretch-blow and the cooling phase. 
     FIG. 27 a  is the same sequential view shown in FIG. 27 with the exception that an internal component  103  with inner liner  114  has been placed in a molded preform  89  while still at an elevated temperature. The molded preform  89  is being stretch-blown into a multi-layer hollow article  86  with an internal component  103  and inner liner  114  in intimate contact with the neck  108  and body portion of the hollow article  86 . 
     FIG. 28 is a side view of a multi-row stretch-blow molding apparatus as described in detail in connection with FIG. 21 showing from right to left a plasticizer  10 , preform molding unit  12 , with an internal component sorting unit  102  and an indexing sorting conveyor  104  which brings internal components  103  beneath a multitude of internal component pick-up and inserting devices  109 . The component pick-up and inserting devices  109  are lowered towards the internal components  103  or internal components with inner liners  114  (not shown) in position on the indexing sorting conveyor  104  by moving means  112  and pick up the internal components  103  through monitoring motions of the central moving means  113 . Internal components  103  are held in a waiting position (not shown) until the universal gripper assembly  27  transfers the molded preforms with internal component preparation  108  (not shown) at elevated temperature in position and then places the internal components  103  (not shown) or internal components with inner liners (not shown) into the molded preforms (not shown) prior to the completion of the shrinkage phase of the molded preforms. 
     The reinforced molded preforms (not shown) are then transferred to a conditioning unit  31 , lowered into a stretch blow molding unit  40  and transformed into hollow articles  86  with reinforcing internal components  103  (not shown) or internal components with liners  114  (not shown) are stretch-blown into multi-layer hollow articles (not shown) which are retracted onto an oriented discharge unit  58 . 
     FIG. 29 is a schematic top view of a multi-row stretch-blow-molding apparatus as described in detail in connection with FIG. 25 showing from right to left the plasticizers  10  and  11 , respectively, the preform molding unit  12 , with sorting unit  102  to line up internal components  103  or internal components with inner liners  114  (not shown) onto an indexing sorting conveyor  104 , a conditioning unit  31 , a stretch blow unit  40 , robot  28 , with a universal gripper assembly  27  mounted on a traversing beam  61 , as well as a secondary stretch blow molding unit  105 , an oriented discharge unit  58  beneath a secondary robot  111  with a universal secondary gripper assembly  106  mounted onto a secondary traversing beam  107 . 
     FIG. 30 shows a schematic side view sequence basically described in connection with FIG. 26 of a robot  28  with a universal gripper assembly  27  from right to left starting at a molded preform take-out position  77 , indexing to an internal component inserting position  110 , traversing to a preform conditioning position  78 , descending onto a preform stretch blow molding position  79 , leaving the pretreated molded preforms in a blow-mold assembly  41  (not shown), returning to a gripper-waiting position  81 , and ascending back towards a preform pick-up position  82 . 
     Simultaneously, a secondary robot  111  with a universal gripper assembly  106  picks up the pretreated molded preforms  89  (not shown) from the position  79  and transfers the same into a secondary or a multitude of subsequent stretch blow molding positions  97  prior to releasing the finished hollow articles in an oriented discharge position  80 . 
     It will be understood by those skilled in the art that each of the elements described above, or two or more together, may also be used in alternate methods of producing molded articles therein and in other methods and apparatuses for the preparation of molded articles. 
     While the invention has been described in detail in the foregoing specification and drawings as embodied in the context of a single-row and a multi-row stretch blow molding method and apparatus for the preparation of molded articles, it will be appreciated that the description is not intended to be limited to the details shown and various modifications and structural changes may be made without departing from the spirit and scope of the invention.