Abstract: A plastic bucket includes at least one undercut adjacent an upper end of the bucket defined by a bucket wall which extends upwardly and inwardly along a diagonal path. An annular, vertical section may be provided at the upper end of the diagonal path. Above the vertical section, the bucket wall extends radially outwardly to create an annular, horizontal flange. In addition, an uppermost annular rim may extend upwardly from the horizontal flange and be located approximately midway between inner and outer radii of the flange.

Abstract: A plastic container lid is adapted for openable attachment to a container. The lid comprises a main lid member having a peripheral, annular outer first wall. The lid also comprises an outer ring member carried on the annular outer wall of the main lid member in sealed but separable relation. The outer ring defines second and third spaced walls to form an annular space which receives the annular lip of a container in locking relation therewith. The main lid member is removable from and reattachable to the outer ring member by the user while carried on the annular container lip. Thus, the outer ring member effectively becomes part of the container, being attached by a permanent snap-fit connection, to improve the hoop strength of the container along with other advantages as described herein.

Abstract: A mold gate and a method of using the same, in which the mold gate has an adjustable-area and width, annular access opening to each mold cavity. As the area is adjusted, the flow of molten plastic to the cavity is controlled for the injection molding of plastic parts. The adjustment may be made by rotating an outer rotary bushing relative to an inner stationary bushing, which is surrounded by the outer rotary bushing in one embodiment, and which projects beyond it in another. The position of a hot probe is thus controlled to vary the area of the access opening. Cooling lines in the vicinity of the hot probe may be provided for significant improvement of operation. Also, a method is disclosed in which the gate operates without closure by means of metal parts. Rather, the frozen molding compound itself serves to close the gate between mold shots.

Abstract: Method and apparatus for adjusting either the flow area to a constant size mold gate or the area of a variable mold gate opening in order to control the flow of molten plastic to a mold cavity for the injection molding of plastic parts, such adjustment being made by rotating an outer rotary gate bushing relative to an inner stationary hot sprue bushing which is surrounded by said outer rotary gate bushing.

Abstract: A snap-on flexible lid for a container comprises a flat lid face and an annular, peripheral flange extending normally of the lid face to enclose and grip an annular lip of a container. The term "annular" is intended to include all closed loops, for example those of rectangular containers. The flange comprises spaced panels angled inwardly from the remainder of the flange to engage the underside of the container lip. This promotes retention of the lid on the container and permits a container where the flange is essentially free of circumferential tear lines, avoiding problems of lid pop-off, and undesired tearing of the circumferential tear lines in the event the container is dropped. The angled panels are defined between pairs of cutting apertures to permit the separation of the sections defining the panels by a pair of vertical cuts, for opening of the container.

Abstract: A plastic container defines a sidewall closed at one end and open at the other end. A container lip is defined at the other end which comprises a pair of spaced walls surrounding the longitudinal axis of the container, to define a recess between the walls for receiving and locking a peripheral container lid portion on the container. The outer of the pair of walls defines at least one pair of spaced points of tearing weakness to permit breaking of the outer wall and outward folding of that part of the outer wall positioned between the points of tearing weakness, to provide access to the peripheral lid portion for lid removal. The container may be designed so that the lid cannot be removed without the breaking of the points of tearing weakness, to provide tamper indication to the container and lid.

Abstract: An injection mold typically defines multiple cavities. A mold gate is provided which comprises a rotary spherical member having a sprue conduit extending transversely therethrough. Highly accurate sequential molding of multiple cavities can be achieved in this manner, as well as other advantages. Also, this arrangement permits a linear, straight sprue conduit which is free of any sharp turns.

Abstract: A plastic container lid is adapted for removable attachment to a container. The lid comprises spaced inner and outer peripheral walls defining between them a substantially annular sealing seat for a lid retaining ring carried by the container. The outer wall of the lid defines inwardly-positioned projection means to engage the retaining ring of the container, to facilitate retention of the lid on the container. The outer peripheral wall defines at least one circumferentially extending line of tearing weakness to permit separation of at least some of the inwardly positioned projection means from the remainder of the lid. The lid outer wall defines one or more apertures or recesses to provide access to a pry member, to allow prying of the lid away from its retention on a container while causing the line of weakness to tear, permitting removal of the lid and at least partial separation of the projection means from the lid.

Abstract: An injection mold typically defines multiple cavities. A mold gate is provided which comprises a rotary spherical member having a sprue conduit extending transversely therethrough. Highly accurate sequential molding of multiple cavities can be achieved in this manner, as well as other advantages. Also, this arrangement permits a linear, straight sprue conduit which is free of any sharp turns.

Abstract: An injection mold typically defines multiple cavities. A mold gate is provided which comprises a rotary spherical member having a sprue conduit extending transversely therethrough. Highly accurate sequential molding of multiple cavities can be achieved in this manner, as well as other advantages. Also, this arrangement permits a linear, straight sprue conduit which is free of any sharp turns.

Abstract: Containers are provided with externally positioned interlock means to engage the corresponding interlock means of other identical containers. This causes the containers to be temporarily retained together without relative motion transverse to their axes except for possible rotational motion about their axes. Additionally, relative motion parallel to their axes can be prevented. Significant advantages are achieved by this when the containers are being processed along a conveyor system, and when they are stacked in large stacks.

Abstract: A container is made of a substantially flexible material. A circumferentially extending array of longitudinally extending teeth are carried by the container and spaced from each other by recesses of a shape proportioned to receive identically-shaped teeth of an adjacent container of similar shape. The teeth each define a transversely enlarged, radially outer portion relation to a radially inner portion. The portions are proportioned to permit snap-fit, locking engagement of a tooth of the container between a pair of teeth of the adjacent container of similar shape.

Abstract: A screw top container lid defines child-proof opening means which are especially suitable for use with container lids of large size. The container lid has a top wall and a peripheral wall with an inner surface, typically with screw threads for attachment to a container lip. The inner surface of the peripheral wall also defines a ratchet for engagement with corresponding ratchet on a container when the lid is applied to it, to permit screw-threaded rotation of the lid in a tightening direction to seal the lid on the container in a closed condition, but to prevent counterrotation of the lid to permit removal from the container. A portion of the peripheral wall defines removable tear strip means. The tear strip carries at least some of the ratchet of the peripheral wall, with the result that a container carrying the lid in its closed condition may be opened by removing the tear strip to facilitate counterrotation of the lid.

Abstract: A mold which comprises a pair of mating, openable and closeable mold halves and a lock to hold the mold halves together. The lock is defined by a recess in the outer surface of one of the mold halves. A lifting bridge crosses the recess, being proportioned to permit a lifting hook in the recess to pass underneath to engage the bridge. An elongated member is secured to the other of the mold halves, being slidably extendable into the recess when the mold halves are substantially closed. The elongated member defines a longitudinal slot facing outwardly of the recess in closed position to receive at least a portion of the lifting hook as the hook engages the bridge. The slot defines an end opposed to the other mold half which is closed, to prevent a hook portion in the slot from sliding past the opposed end. Thus, the mold in closed position cannot be opened while the lifting hook is present in the slot.

Abstract: A mold comprising a mold core and mold cavity defines means which permits and controls a slight outward stretching of the mold cavity from a first positively centered position to a second positively centered position. By this means, precision centering of the mold and core can be achieved even under ultra high molding pressures without significant core shift.

Abstract: A mold comprises a molding chamber, a sprue aperture communicating with the chamber for introducing molding compound into the chamber, and a mold gate for regulating molding compound flow through the sprue aperture. In accordance with this invention, the mold gate comprises flexible flap means positioned to restrict flow of molding compound through the sprue aperture. The flap means is positioned to be flexed toward the molding chamber by pressurized molding compound, to permit increased flow of the molding compound through the sprue aperture into the molding chamber. The flap means is capable of returning to their original shape when the pressurized molding compound is substantially released of its pressure, particularly in the circumstance where a suction step in the molding compound pressure cycle provides a negative pressure. The flap means in its original shape at least substantially obstructs the sprue aperture.

Abstract: A mold, typically an injection mold, having a mold core and a mold cavity has centering rib means at its parting line defined on one of the core and cavity, projecting in the closed position into a groove defined by the other of the mold core and cavity in the closed position. By this invention a wear member is removably secured in the groove at a position which is radially inward of the centering rib. The wear member defines a radially outer face that is acutely angled outwardly from the longitudinal axis of the mold relative to the centering rib. The radially inner surface of the centering rib defines a plane parallel to the radially outer face and positioned whereby the radially outer face and radially inner surface abut each other in the closed position.

Abstract: A mold, typically an injection mold, comprises a cavity member and a core member relatively movable between open and closed positions to define a first parting line and a molding chamber between the core and cavity members in the closed position. A sprue aperture is provided, communicating with the molding chamber to provide molding compound to the chamber. In accordance with this invention the cavity member defines forward and rearward portions movable between open and closed positions and proportioned whereby objects molded in the molding chamber can be removed from between the forward and rear portions when the cavity member is in its open position.

Abstract: A mold comprises a pair of openable and closeable mold halves separable along a parting line. By this invention, each mold half defines a recessed outer surface portion which communicates with the recessed portion of the other mold half in the closed position. Each mold half defines a bridge portion which extends over its recessed portion and is positioned adjacent to the parting line. Thus, a lifting hook may pass into the recess defined by the outer surface portion to engage the bridge portion of a separate mold half, or to engage both bridge portions of both mold halves in the closed position.

Abstract: A plastic lid for a container comprises a lid body and an annular, peripheral gripping flange for retaining the lid on the container. In accordance with this invention, the flange defines at least a pair of spaced, circumferential sections, each section having opposed ends which each define a break-away flange portion. Each spaced section defines means permitting outward folding of the section upon breaking away of the connected break-away flange portions to facilitate opening. Alternatively, the gripping flange may define a zigzag tear line for removal of spaced, enlarged portions of the gripping flange to facilitate opening, while permitting remaining portions of the gripping flange to provide some retention of the lid to its container.