IL31829A - Improvements in oscillating beds for moulding hollow plastic articles by blowing - Google Patents

Description

Improvements in oscillating bede for Tnoulding hollow plastic articles by blowing O The present invention relates to improvements in beds for moulding holloAv plastic bodies by A machine for moulding hollow plastic articles by the process is already which comprises essentially a vertical extruder having associated therewith at least one moulding bed of the oscillating This bed comprises essentially a pair of movable parallel frame members between which mould carrier trays are slidably mounted to constitute a assembly rigid with a horizontal lating shaft trunnioned to the upper portion of the fixed part of said The oscillating assembly is movable between two end namely an upper position sponding to the wherein the extruded parison is clamped the mould and a lower position in which the moulds are opened and the moulded articles ejected As a the oscillating motion is controlled by a reciprocating driving device incorporating a It is the object of this invention to provide an improvement in a moulding bed of this general type with a view to facilitate the operation while proving the safety conditions during this To this the moulding bed for hollow plastic articles produced according to the extrusion and blowing which is of the oscillating comprising a mould carrier assembly rigid with an oscillating shaft trunnioned to a fixed frame and coupled to a reciprocating driving is characterized in that the oscillating shaft is furthermore coupled through a train of reducing gears to a manual drive shaft rotatably mounted on said fixed frame With this when a mould change is to be performed it is only necessary to uncouple the ting shaft from its driving device and to rotate the driving shaft manually so as to cause the complete mould carrier assembly to pivot outwards with respect to the bed to a horizontal position symmetrical to the upper position in which the mold is with respect to the axis of Once the mould carrier assembly has been brought to this it is particularly easy to remove the mould which can subsequently be received by a truck for removing the used mould and replacing same with a fresh Now a typical form of embodiment of this tion will be described by way of example with reference to the attached in Figure 1 is a diagrammatic view ing an moulding machine equipped with an oscillating bed according to this Figure 2 is a front elevational view of the same The moulding machine illustrated diagrammatically in the drawing comprises essentially a vertical axis extruder 1 which only the head is and a moulding bed of the oscillating denoted as a whole by the reference numeral This bed comprises a fixed frame structure consisting of a pair of uprights 3 and 4 braced by tudinal members and having an oscillating shaft 5 ed to its upper This shaft 5 is rigid with a movable moulding assembly 10 comprising essentially a pair of transverse frame members 6 and 7 braced by nal columns 8 on which mould carrier trays 9 and 9a are slidably Secured to these trays 9 and 9a are the two halves or sections 11 and 11a of the mould and the sliding movement of the mould carrier trays 11 and 11a is controlled by separate cylinders 12 and 12a carried by said frame members 6 and The movable assembly 10 also carries a suitable blowing system the pipe or needle not shown in order to simplify the The oscillating motion of shaft 5 is controlled cylinder and piston actuator comprising by cylinder 13 pivoted at 14 to the upright 4 and having its piston rod 15 pivotally connected at 16 or crank to a strap 17 carried by the outer end of a radial rigid with the end of shaft to each complete reciprocation of the piston rod 15 of cylinder 13 there corresponds a complete oscillating cycle of shaft The movable assembly 10 comprising the frame members 6 and 7 and the mould carrier trays will thus oscillate between an uppermost position corresponding to the as shown at 10a in Figure and a lowermost sition In the upper position the two mould halves or sections are closed against the plastic parison delivered by the extruder and the moulded hollow objects are blown and cooled during the downward movement of rotation of the movable assembly 10 from the upper position 10a to the lower position In this lower position the moulded objects are eject After this the movable assembly is moved back from the lower position 10b to the upper position 10a and the cycle is The amplitude of the oscillating movement is about as shown diagrammatically in Figure To facilitate the replacement of the mould halves or sections 11 and 11a a device is provided which is capable of bringing the complete movable assembly 10 to a horizontal position 10c externally of the this horizontal position being in relation to the axis of to the upper position 10a in which the mould is To this the oscillating shaft is rigid with a worm wheel 19 in constant meshing engagement with a worm 21 trunnioned in supports 22 and secured to the uprights 4 of the fixed frame The worm 21 has a stub shaft extension 24 for manually operating the worm for by means of a hand heel engaging a end of said stub Of any other type of train of gears may be provided between the oscillating shaft 5 and the manual control shaft The mould replacement operation is particularly easy to form because of the ease with disengagement can be effected of the drive between the oscillating shaft on the one hand and the cylinder and piston actuator on the it is only necessary to firstly uncouple the shaft 5 from the driving cylinder 13 by disconnecting the piston rod 15 of this cylinder from the strap by removing the pivot pin Having thus of a handwheel the manual control shaft 24 in the proper so as to drive the oscillating shaft 5 and therefore the movable assembly 10 in the direction as shown in Figure the movable assembly 10 will be moved from the lower position 10b to the rizontal position 10c which is symmetrical in relation to the upper position respect to the axis of lation The replacement of the mould by another one can subsequently be carried out very easily by utilizing a lift truck 25 engageable between the pair of uprights 3 and 4 of the The movable tray 26 of this lift truck is brought to its uppermost position beneath the mould halves so that it can receive these mould halves after they have been separated from the mould carrier trays 9 and 9a of the The preceding mould is thus easily removed and the fresh mould inserted in the same fashion by raising it by means of the lift truck tray 26 to the proper position so that it can be cured to the carrier trays of the From the foregoing it is clear that the mould replacement operation takes place with the maximum safety since the moulds are safely prevented from falling on the floor as a consequence of mishandling or for other In the case of a twin moulding bed this mould replacement operation may be carried out on one bed while the other bed continues its normal in order to minimize According to a modified form of embodiment the worm 21 is so mounted on its supports 22 and 23 that it cannot mesh with the worm wheel 19 during the normal ration of the moulding Under these the mould change operation cannot take place unless the worm 21 is restored to its position of normal meshing ment with the worm gear so that the shaft 5 can be driven means of a Of the forms of embodiment described hereinabove with reference to the accompanying are given by way of example only and should not be trued as limiting the present invention since many fications and variations may be brought thereto without departing from the spirit and scope of the invention as set forth in the appended insufficientOCRQuality

Claims (1)

1. CLAIMS 1 · Bed of the oscillating type for molding hollow plastic articles by blowing, which comprises a fixed frame structure* an oscillating shaft trunnioned in said fixed frame structure, a mold-supporting assembly rigid with said oscillating shaft, a crank adapted to determine the oscillating movements of said shaft, a cylinder and piston actuator pivoted at one end to said fixed frame structure and at the opposite end to the free end of said crank and adapted to produce a limited oscillation of said oscillating shaft for transferring the mold-supporting assembly from the upper position in which said mold is adapted to be filled and closed to the lower position for opening and e ecting the molded article,, means permitting an easy disengagement of the drive between actuator and oscillating shaft, a manually operated shaft rotatably mounted in said fixed frame structure and a train of reduction gears coupling said oscillating shaft to said manually operated shaf whereby the mold-supporting assembly, after uncoupling said actuator from said oscillating shaft,; can be moved from its lower position to an upper position symmetrical to the upper position in relation to said oscillating shaft* 2· Moulding bed according to claim 1, characterized in that said oscillating shaft is rigid with a worm wheel in meshing engagement with a worm trunnioned in two bearings carried by said frame structure, said worm being rigid with the manual drive shaft of which the outer end is shaped to permit its driving connection with a handwheel or similar drive member* 3. Moulding bed according to claimAi, characterised in that said oscillating sha is rigid with a radial arm carrying a strap at its outer end, said strap being detachably connected by means of an «· Q ■—> 31829/2 easily removable pivot pin to the piston rod of a fluid-actuated control cylinder. 4· Moulding bed substantially as described hereinabove and illustrated in the accompanying drawings* For the Applicants DR. XHHOLD COHN AND PARTNERS