US5266247A — Molding cycle control method of an injection mold…

Claim 1

Independent Claim 328 words

A molding cycle control method for an injection molder comprising a cylinder with a screw therein and a flow passage opening and closing mechanism which is provided between the cylinder of the injection molder and a gate of a mold, the mold having a mold cavity, the opening and closing mechanism provided for the flow of a plasticized synthetic resin between the inside of the cylinder and the cavity of the mold, the method comprising the following steps: (a) a pre-injection pressing process wherein after the synthetic resin is plasticized and measured, with the flow passage opening and closing mechanism closed to prevent the flow of the plasticized synthetic resin, a predetermined pushing force is applied to the screw to set the resin pressure value inside the cylinder equal to a predetermined value, (b) a filling and dwelling process comprising a filling process wherein with the flow passage opening and closing mechanism open to allow the plasticized synthetic resin to flow, the screw is moved forward to inject and fill the plasticized synthetic resin into the cavity of the mold, and a dwelling process to apply a predetermined pushing force to the screw following the filling process, during which the flow passage opening and closing mechanism is closed the filling and dwelling process being conducted to fill a predetermined amount of the plasticized synthetic resin into the cavity, (c) a measuring process wherein with the flow passage opening and closing mechanism closed to block the flow of plasticized synthetic resin, the screw is rotated and moved backward to measure a predetermined amount of the plasticized synthetic resin for a next molding cycle, and (d) a suck-back process wherein with the flow passage opening and closing mechanism open to allow the plasticized synthetic resin to flow, the screw is moved backward to lower the pressure of the plasticized synthetic resin located between the gate of the mold and the front end of the screw at its forward movement side.

Claim 2

Dependent Claim 328 words

A molding cycle control method for an injection molder comprising a cylinder with a screw therein and a flow passage opening and closing mechanism which is provided between the cylinder of the injection molder and a gate of a mold, the mold having a mold cavity, the opening and closing mechanism provided for the flow of a plasticized synthetic resin between the inside of the cylinder and the cavity of the mold, the method comprising the following steps: (a) a pre-injection pressing process wherein after the synthetic resin is plasticized and measured, with the flow passage opening and closing mechanism closed to prevent the flow of the plasticized synthetic resin, a predetermined pushing force is applied to the screw to set the resin pressure value inside the cylinder equal to a predetermined value, (b) a filling and dwelling process comprising a filling process wherein with the flow passage opening and closing mechanism open to allow the plasticized synthetic resin to flow, the screw is moved forward to inject and fill the plasticized synthetic resin into the cavity of the mold, and a dwelling process to apply a predetermined pushing force to the screw following the filling process, during which the flow passage opening and closing mechanism is closed the filling and dwelling process being conducted to fill a predetermined amount of the plasticized synthetic resin into the cavity, (c) a measuring process wherein with the flow passage opening and closing mechanism closed to block the flow of plasticized synthetic resin, the screw is rotated and moved backward to measure a predetermined amount of the plasticized synthetic resin for a next molding cycle, and (d) a suck-back process wherein with the flow passage opening and closing mechanism open to allow the plasticized synthetic resin to flow, the screw is moved backward to lower the pressure of the plasticized synthetic resin located between the gate of the mold and the front end of the screw at its forward movement side.

Claim 3

Dependent Claim 61 words

The molding cycle control method of an injection molder as set forth in claim 1, wherein in the pre-injection pressing process, a check valve mounted to the screw is closed to prevent a flow of the plasticized synthetic resin placed between the flow passage opening and closing mechanism and the check valve toward the direction of backward movement of the screw.

Claim 4

Dependent Claim 64 words

The molding cycle control method of an injection molder as set forth in claims 1 or 2, wherein during the dwelling and filling process, a predetermined amount of the plasticized synthetic resin to be filled in the cavity is determined based on the positional value of the screw or pressure values of the plasticized synthetic resin placed in the cylinder or in the cavity.

Claim 5

Dependent Claim 63 words

The molding cycle control method of an injection molder as set forth in claims 1 or 2, wherein during the dwelling and filling process, a predetermined amount of the plasticized synthetic resin to be filled in the cavity is determined on the basis of a predetermined travel distance of the screw from the position where the screw is positioned immediately before the injection.

Claim 6

Dependent Claim 173 words

The molding cycle control method of an injection molder as set forth in claims 1 or 2, wherein a predetermined amount of the plasticized synthetic resin to be filled in the cavity during the dwelling and filling process is represented by the following formula with a weight value G: G=(1V.sub.I -1/V.sub.H)×V+A×X/V.sub.H wherein: V I is a specific volume value of plasticized synthetic resin placed at its forward movement side of the front end of the screw in the cylinder immediately before the injection operation; V H is a specific volume value of the plasticized synthetic resin placed at its forward movement side of the front end of the screw in the cylinder during the dwelling process; V is a volume of the plastifiable synthetic resin placed at its forward movement side of the front end of the screw in the cylinder immediately before the injection operation; A is an internal sectional area of the cylinder; and, X is a travel distance of the screw from immediately before the injection to the dwelling operation.

Claim 7

Dependent Claim 42 words

The molding cycle control method of an injection molder as set forth in claim 1, wherein the suck-back process is carried out with the plasticized synthetic resin placed in the gate of the mold solidified and blocked from flowing in the gate.

Claim 8

Dependent Claim 25 words

The molding cycle control method of an injection molder as set forth in claim 1, wherein the suck-back process is conducted during the measuring process.

Claim 9

Dependent Claim 39 words

The molding cycle control method of an injection molder as set forth in claim 1, wherein after the completion of the measuring process, the flow passage opening and closing mechanism is open and the suck-back process is carried out.

Claim 10

Dependent Claim 192 words

A control method for an injection molder comprising a cylinder having a screw therein and a flow passage opening and closing mechanism between the cylinder and a gate of a mold having mold cavity to selectively block the flow of resin between the cylinder and the mold, the method comprising: a filling step comprising advancing the screw in the cylinder with the flow passage opening and closing mechanism open to inject resin from the cylinder into the mold cavity; a dwelling step comprising applying a predetermined pressure to the resin injected into the cavity of the mold with the screw; a measuring step comprising closing the flow passage opening and closing mechanism while the predetermined pressure is being applied, and retracting the screw to measure a predetermined amount of resin in the cylinder for the next molding cycle while the flow passage opening and closing mechanism remains closed; a suckback step occurring after the resin has solidified in the gate of the mold comprising opening the flow passage opening and closing mechanism and retracting the screw to reduce the pressure on the resin between the front of the screw and the gate.

Claim 11

Dependent Claim 192 words

A control method for an injection molder comprising a cylinder having a screw therein and a flow passage opening and closing mechanism between the cylinder and a gate of a mold having mold cavity to selectively block the flow of resin between the cylinder and the mold, the method comprising: a filling step comprising advancing the screw in the cylinder with the flow passage opening and closing mechanism open to inject resin from the cylinder into the mold cavity; a dwelling step comprising applying a predetermined pressure to the resin injected into the cavity of the mold with the screw; a measuring step comprising closing the flow passage opening and closing mechanism while the predetermined pressure is being applied, and retracting the screw to measure a predetermined amount of resin in the cylinder for the next molding cycle while the flow passage opening and closing mechanism remains closed; a suckback step occurring after the resin has solidified in the gate of the mold comprising opening the flow passage opening and closing mechanism and retracting the screw to reduce the pressure on the resin between the front of the screw and the gate.

Claim 12

Dependent Claim 61 words

The method according to claim 9 wherein the measuring step comprises a first measuring step in which the a first predetermined amount of resin is measured in the cylinder before the suckback step, and a second measuring step in which an additional amount of resin is measured in the cylinder after the suckback step and prior to the next molding cycle.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-11-29	1997-05-31	1997-11-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-11-29	2001-05-31	2001-11-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-11-29	2005-05-31	2005-11-30	$7700.00	Window Closed / Lapsed

Molding cycle control method of an injection molder

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