GB2236072A

GB2236072A - Injection moulding apparatus

Info

Publication number: GB2236072A
Application number: GB8919114A
Authority: GB
Inventors: Gerald Dennis Day
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-23
Filing date: 1989-08-23
Publication date: 1991-03-27
Also published as: GB8919114D0

Abstract

Injection moulding apparatus includes an injection nozzle (11) carried on a hollow arm (10) which is mounted for pivoting relative to a hollow body (8). The body and the arm have internal passages which communicate with the injection nozzle. Prior to injection, the arm (10) is pivoted downwards by a cylinder and toggle mechanism (15) (16) to urge the nozzle under pressure against a moulding tool (not shown). After injection, the arm (10) is pivoted upwards to clear the moulding tool. <IMAGE>

Description

SPECIFICATION.

TILTLE:- PLASTICS INJECTION APPARATUS.

MOST MOULOING MACHINES HAVE IN LINE INJECTION HEADS THATOPERATE VERTICALLY OR HORIZONTALLY. ON SMALLER MACHINES THE HORIZONTAL POSITION IS SOMETIMES DIFFICULT TO ALIGN WITH THE TOOL WHICH ALLOU LEAKAGE AT THE MOZZLE WHICH CAN BUILD UP AND DAMAGE THE HEATING ELEMENTS. THE VARYING LEVEL OF MATHERIAL IN THE HOPPER CAN ALSO AFFECT THIS ALINGMENT.

HORIZONTAL ARRANGEMENTS TAKE UP A LARGE AREA EYE@ ON THE SMALLER MECHINES. A FURTHER MORE SIGNIFICANT FACT IS THE RECHARGE OFERATION THE SPEED OF WHICH HAS TO BE CONTROLLED SINCE THIS OPERATION MAINTAINS THE INJECTION NOZZLE AGAINST THE DIE OR TOOL TO ESTABLISH A BACK PRESSURE WHICH IF GREAT WILL FLASH THE COMPONENTS IN THE DIES.

ACCORDING TO PRESENT INVENTION THERE IS PROVIDED A MAIN BOOY CONTAINING SLIDEWAYS AND A MECHANICAL ARRANGEMENT THAT PERMITS ITS ADJUSTMENT THAT OPERATES THREADEO SHAFTS TO HIGHER OR LOWER THE INJECTION APPARATUS. MOUNTINGS PROVIDED TO SUPPORT THE APPARATUS WHEN INSTALLED. THE INJECTION BASE HAS FIXED GUIDE BARS AND A FRAME STRUCTURE SUPPORTING CYLINDERS THAT PROVIDE THE INJECTION PRESSURE THROUGH A GUIDED BASE PLATE.A MECHANICAL MOTOR ROTATIONAL DRIVE VIA A PROTECTION CLUTCH UNIT TO ITS CENTRALLY POSITIONED INJECTION SCREW WHICH OPERATES VERTICALLY UPWARDS, MATERIAL INPUT THROUGH A COOLES SECTION OF THE ENCASED VERTICALLY MOUNTED HEATER SECTION, WHICH IS FULLY CONTROLABLE, FEEDS GRANUELS UPTO THE HEATED ZONE FORCING MOULTERN MATERIAL VERTICALLY UPWARDS TO A SWIVEL UNIT WHICH PASSES THE MATERIAL HORIZONTALLY ALONG A FURTHER HEATED AND CONTROLLED ARM AND DONNWARDS THROUGH A HEATED & CONTROLLED INJECION NOZZLE. THE HEATED ARM CONTAINING A SHUT OFF VALYVE AND SUCK BACK PISTON BOTH INTERLOCKED AND DRIVEN THROUGH A HIGH LEVERAGE TOGGLE ARRANGEMENT WHICH IS CYLINDER ACTIVATED. SPRINGS PROVIDED RESISTANCE TO THE UPWARD MOVEMENT MAKING THE SHUT OFF VALUE & BR< SUCK BACK OPERATE PRIOR TO THE INJECTION NOZZLE BEING RAISED.

THE WHOLE ARRANGEMENT BEING A POWERFUL, COMPACT PIECE OF PLASTIC INJECTION APPARATUS.

A SPECIFIC EMBODIMENT OF THE INVENTION WILL NOW BE DESCRIBED BY WAY OF EXAMPLE WITH REFFERNCE TO THE ACCOMPANYING DRAWINGS IN WHICH: FIGURE 1. SHOWS A PERSPECTIVE VIEW OF THE ASSEMBLED INJECTION APPARATUS REFERRING TO THE DRAWINGS THE APPARATUS COMPRISES A MAIN BODY 1 MOUNTED ON THE BEARINGS AND SLIDE BARS 2 SUPPORTED BY BRACKETS 3 ALSO USED FOR FIXING ON INSTALLATION.

THE MAIN SOBY ALSO CONTAINS A MECHANICAL ARRANGEMENT OPERATED BY THE HANDWHEEL, COUPLINGS AND SHAFT SET 7 PROVIDING HORIZONTAL MOVEMENT TO ADJUST THE INJECTION NOZZLE 11 OVER THE TOOL. A FURTHER MECHANICAL ARRANCEMENT ROTATES THREADED SHAFTS VERTICALLY MOUNTED WITHIN THE COVER TUBES 5 THESE THREADED SHAFTS BEING CONNECTED TO THE INJECTION HEAD MOUMTING 4 AND ROTATED BY THE HANDWHEEL, COUPLES AND SHAFT SET 6. THE INJECTION HEAD MOUNTINGS 4 IS CONNECTED VIA SIDE PLATES 16 AND GUIDE BARS 15 TO THE END BASE PLATE 17 ONTO WHICH IS MOUNTED CYLINDERS 18 THAT PROVIDE THE INJECTION PRESSURE THROUGH THE GUIDED BOX PLATE 19. A MECHANICAL GEAR BOX 20 IS POWERD THROUGH SHAFTS AND COUPLES SET 23 AND DRIVES THE INJECTION SCREW CONTAINED IN THE VERTICAL ENCASED HEATER TUBE ARRANGEMENT 8.

RAN MATERIAL IS FED INTO THE WATER COOLED CASING 23, WHICH IS FIXEO TO THE INTAKE HOLE 22 ONTO WHICH A SMALL HOPPER WOULD BE ATTACHED. HEATERS AND THERMOCOUPLES PROVIDE A MELTING PROCESS CONTAIED WITHIN THE VERTICAL UNTT 8. MOULTEN MATERIAL PASSING THROUGH THE SEALED SWIVEL PIN 9 AND ON INTO THE HORIZONTAL ARRM 16.

HEATER AND THERMOCOUPLES BEING SITED ALONG THIS ARM 10 TO MAINTAIN AND CONTROL THE FLUIDITY OF THE MATERIAL. ON INJECTION THE MATERIAL WOULD BE PASSED TO THE TOOL VIA THE NOZZLE 11 VERTICALLY DOWNWARDS. PRECEDING INJECTION THE CYLINDERS 15 WOULD PULL DOWN THE HORIZONTAL ARM 10 VIA A HIGH LEYERAGE TOGGLE MECHANISM 16. THIS MECHANISM 16 IS CONNECTED VIA THE SHUT OFF YALUE ROD 13 TO A LEVER 24 WHICH IS PIVOTED It A BRACKET 14 MOUNTED ON TOP OF THE HORIZONTAL ARM 10.

THIS LEVER 24 IS FINALLY CONNECTED TO THE SUCK BACK PISTON ROD 12. INJECTION COMPLETED THE CYLINDER 15 WOULD RAISE THE TOGGLE MECHANISM 16 RESISTANCE SEING MET CAUSED BY TENSION SPRINGS 17 TO OVERCOME THIS RESISTANCE THE TOGGLE MECHANISM 16 WILL OPERATE THE SHUT OFF VALUE ROD 13 AND IT CONNECTED LEVER 24 CAUSING THE SUCK BACK PISTON ROD 12 TO OPERATE THIS COMPLETED CYLINDER WOULD RAISE THE ARM CLEARING THE NOZZLE FROM THE TOOL. THE SHUT OF VALUE OPERATED THE INJECTION SCREW WOULD BE DRIVEN BY THE MOTOR 2.1 TO RECHARGE THE SYSTEM DRAWING IN NEW MATERIAL THROUGH THE APERTURE

Claims

CLAIMS 1. Injection apparatus comprising a main body and injection means mounted on the main body for movement relative thereto.
2. Apparatus according to Claim 1 including a screw mechanism for moving the injection means relative to the main body.
3. Apparatus according to Claim 2 further comprising guide bars for guiding the injection means for movement relative to the main body.
4. Apparatus according to any preceding claim wherein the injection means comprises first and second hollow members arranged for relative pivoting and having respective internal passages which communicate with each other, one of said members having an injection nozzle through which there can be expelled material to be injected and wherein there is provided driving means for pivoting one of said members relative to the other member.
5. Apparatus according to Claim 4 wherein the driving means includes a toggle mechanism.
6. Apparatus according to Claim 4 or Claim 5 wherein one of said members includes a shut-off valve and a suck-back piston.
7. Injection apparatus substantially as hereindescribed with reference to the accompanying drawing.
8. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.