Plastic article or earthenware shaping or treating: apparatus – Control means responsive to or actuated by means sensing or... – Feed control of material en route to shaping area
Reexamination Certificate
2000-07-18
2003-10-28
Heitbrink, Jill L. (Department: 1732)
Plastic article or earthenware shaping or treating: apparatus
Control means responsive to or actuated by means sensing or...
Feed control of material en route to shaping area
C425S146000, C425S19200R, C425S564000, C425S572000
Reexamination Certificate
active
06638049
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to readily programmable automatic control of plastic flow through two (or more) separate injection nozzles to the cavities of separate mold inserts which are readily removable from and insertable into a mold housing of an injection molding machine. More particularly the invention relates to a system and method for programming proportional control of plastic flow injection through a nozzle into the cavity of any modular mold insert having any desired cavity configuration and volume different from the cavity configuration/volume of a first modular mold insert which it replaces. Normally, in injection mold apparati/processes, the pressure, flow rate, temperature and other parameters of the polymer fluid(s) and operating parameters of components of the injection mold machine itself, are preselected and fixed throughout an injection mold machine operating cycle according to the size, configuration and volume of the cavity of the mold into which the plastic fluid is to be injected. Such prior systems do not enable the user to vary, control or tailor the fluid flow rate or stop/start of the system with respect to any desired mold cavity configuration/size.
SUMMARY OF THE INVENTION
The present invention provides injection control over two or more modular molds (mold inserts) which are readily removable/changeable/variable and which have different sizes, shapes, volumes or configurations, the injection for which can be independently customized for maximum end product (part) and injection quality, speed of part production and the like using a single existing size and configuration of injection machine screw/barrel, hotrunner(s), manifold(s), actuators, nozzles, valve pins, rotary valves, plungers, shooting pots and the like, the operation of which are readily programmably controllable and can be operationally programmed for maximum performance with respect to each mold insert having any selected part or cavity configuration, size, shape or volume.
In accordance with the invention therefore, there is a provided a system, apparatus and method for selectively and readily controlling the injection flow into the cavities of modular injection mold inserts which are readily replaceable with inserts having different cavities of different size, shape, configuration, volume and the like.
More particularly there is provided, in an injection molding machine, an apparatus for controlling delivery of a fluid material to mold cavities of selectively variable size or configuration, the apparatus comprising:
A modular mold mounting mechanism having mounting apertures for receiving first and second molds having first and second mold cavities of different size or configuration, the mounting apertures being adapted for ready insertion and ready removal of the first and second molds;
A manifold into which fluid material is injected, the manifold having first and second fluid delivery channels through which the fluid material is injected, one channel having an exit aperture communicating with a gate to the cavity of one mold, the other channel having an exit aperture communicating with a gate to the cavity of the other mold;
Each channel being associated with a drive mechanism which is interconnected to and controls operation of a fluid flow controller which varies flow of the fluid material through an associated channel,
A sensor for sensing a selected condition of the fluid material being injected through at least one of the channels or at least one of the mold cavities;
A controller interconnected to each drive mechanism, the controller comprising a computer interconnected to a sensor which receives a signal representative of the selected condition sensed by the sensor, the computer including an algorithm utilizing a value corresponding to a signal received from the sensor as a variable for controlling operation of at least the drive mechanism associated with the at least one channel.
Most preferably the modular mold housing comprises first and second housings readily openable and closeable for enabling ready insertion and removal of the first and second molds.
Typically the apparatus includes a second sensor for sensing a selected condition of the fluid material being injected through the other channel or the other mold cavity, the computer being interconnected to the second sensor and receiving a signal representative of the selected condition sensed by the second sensor, the algorithm utilizing a value corresponding to a signal received from the second sensor as a variable for controlling operation of the drive mechanism associated with the other channel.
Typically, at least one of the channels includes a nozzle having a seal surface surrounding the exit aperture of the channel, the nozzle being expandable upon heating to a predetermined operating temperature, the nozzle being mounted relative to a complementary surface surrounding the gate such that the seal surface of the nozzle is moved into compressed contact with the complementary surface surrounding the gate upon heating of the nozzle to the predetermined operating temperature. At least one of the channels preferably includes a nozzle comprising an outer unitary piece formed of a first material and an inner unitary piece formed of a second material, the first material being substantially less heat conductive than the second material.
The sensor may comprise a pressure transducer interconnected to at least one of the channels or a mold cavity for detecting the pressure of the fluid material. The actuator controller may include a solenoid interconnected to the computer, the solenoid having at least two chambers and a piston controllably movable between selected positions for selectively delivering a pressurized actuator drive fluid to one or the other of the chambers of the actuator.
In one embodiment, at least one channel includes a valve pin interconnected to the actuator controller, the valve pin having a surface for forming a gap with a complementary surface of the at least one channel spaced upstream and away from the gate, the size of the gap being controllably variable to control flow of the fluid material through the gate. The valve pin is reciprocally movable toward and away from the gate and wherein the surface of the valve pin and the surface of the channel are adapted to increase the size of gap as the valve pin is moved away from the gate and decrease the size of the gap as the valve pin is moved toward the gate.
The apparatus may include a plug mounted in a recess of the manifold, the plug having a bore through which a stem of the valve pin passes, the valve pin having a head, the bore of the plug through which the stem passes having a smaller diameter than the valve pin head at the valve pin head's largest point and the recess of the manifold having a larger diameter than the diameter of the valve pin head at the valve pin head's largest point, so that the valve pin can be removed from the manifold from a side of the manifold in which the recess is formed when the plug is removed from the manifold.
The sensor may be selected from the group consisting of a pressure transducer, a load cell, a valve pin position sensor, a temperature sensor and a barrel screw position sensor.
The fluid flow controller is preferably disposed within or communicates with the flow of fluid material through the manifold or one or more of the channels and is typically selected from the group consisting of a valve pin, a rotary valve and a plunger.
Further in accordance with the invention there is provided, in an injection molding system including a manifold having first and second channels to direct fluid material into respective first and second modular cavity inserts each modular cavity insert having respective first and second cavity volumes and shapes, the modular cavity inserts being readily removably mounted in respective first and second receiving apertures in a mold, a method of injection molding comprising the steps of:
(A) independently controlling first and second rates at which f
Kazmer David
Moss Mark D.
Heitbrink Jill L.
Kudirka & Jobse LLP
Synventive Molding Solutions, Inc.
LandOfFree
Apparatus and method for proportionally controlling fluid... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for proportionally controlling fluid..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for proportionally controlling fluid... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3111225