Abstract: A guiding mechanism and method are provided for properly aligning molds or portions thereof, such as ejector plates, as they are cycled. The guiding mechanism is an improvement over conventional bushings which require that the mold in which the bushings are mounted to be removed from the press and disassembled and thereafter, the press fitted bushings are pressed out. Herein, the bushings are provided with a replaceable insert or portion that is easily disconnected from the remainder of the bushing such as by unthreading a threaded insert from a threaded bushing body without removing the mold half from the press. A first replaceable insert can be mounted in the bushing body which is sized to receive the leader pin to guide the leader pins therein and align the mold halves as they are moved to the closed position.

Abstract: An ejector is coated with a thin, hard, low friction, lubricous coating for use in a mold to eject molded articles from the mold without the use of liquid lubricants. The preferred ejector has a thin, low friction, coefficient coating with a thickness on the order of 0.00004 inch to 0.0001 inch. This coating provides long lasting, dry lubrication for low friction reciprocation of the ejector within a bore in the mold. The thin lubricous coating allows the ejector to be inventoried and sold in nominal sizes and cut down to the desired size by the mold builder to suit a specific application, and the cut ends are then deburred by the mold builder and finish ground to size, with the lubricous coating remaining intact at the cut end of the ejector. The coating is so thin that the nominal size of the ejector is essentially unchanged. The very thin coating does not chip or flake at the cut end, as would result in cavities into which the plastic could flow and form flashing on the plastic part being molded.

Abstract: An injection plastic mold is provided with its own on-board monitor or counter, which is actuated with each opening and closing cycle of the mold to maintain a count of the operating cycles performed. This count is maintained with the mold, whether the mold is on the press or a storage rack. The counter or monitor is relatively inexpensive and unobtrusive and is capable of withstanding harsh temperatures and shock that are encountered in an injection molding environment. The counter or stroke monitor may be either a mechanical counter or an electrical counter which is incorporated into a mold half to remain with the mold when it is stored away from a molding machine, when operated during an initial set-up operation, and when operated during a production run. Whether an on-board mechanical counter or an on-board electrical counter, the counter is hermetically sealed against the intrusion of damaging liquids or chemicals and is mounted in a protective housing to protect against shock, etc.

Abstract: In accordance with the present invention there is provided a new and improved internal core lifter for molding and ejecting plastic parts having undercuts. The preferred internal core lifter has a core blade with a first end configured to cooperate with the surfaces of the mold for molding a plastic part and for assisting in safe ejection of the plastic part. The core blade may be pivotally mounted at an opposite end for being disposed at a predetermined molding angle in a range of angles for accommodating various molding angles of mold apparatus. In ejecting the plastic part, the first end of the core blade moves horizontally away from the undercut while moving vertical to assist in safe ejection of the plastic part.

Abstract: An internal core lifter in a mold is provided with both linear motion and pivotal seating in a universal coupling that slides linearly along an ejector plate. The pivotal seating allows the core blade to be used at various angles in different molds, thereby reducing the inventory of core blade needed. To resist high forces encountered during ejection and during the opening and closing of the mold, the preferred pivotal seating comprises wide arcuate dovetail surfaces on the lower end of the core blade and on a slidable support which has linear dovetail surfaces with the ejector plate. The upper end of the core blade may be configured to be part of the molding surfaces to mold an undercut in a plastic part. The upper end of the core blade is moved laterally from the undercut and then is shifted upwardly to engage and eject the part.

Abstract: A multipart mold having a resilient retainer engageable with a pin attached to a mold part to hold the mold part in a desired position relative other mold parts.