CORE BOX WITH LARGE DIAMETER VENTS AND PLUGS

摘要

The disclosure concerns a core box having a drag and a cope forming a mold cavity for forming a sand base core. This sand is injected into the cope and the air in the cavity is vented through vents remote or spaced away from where the sand is inserted. These vents are usually in the drag, but may also be in the cope. In each vent adjacent the cavity is a cylindrical cup-shaped plug having slotted perforations in its bottom narrower than the diameter of the sand grains. The diameter of this perforated vent plug is at least 50% greater and preferably at least twice the width of the cavity, slot, or groove at the vent whereby air can be vented along the cavity. Furthermore, the plug having the perforations may be contoured to the groove or that portion of the cavity in which the vent is located so that air can also be vented from the sides of the cavity or groove. These plugs are held in place by sleeves that contact the rim of the cup and extend to the outside of the mold where the sleeves are held in place by overlapping washers or heads of bolts screwed into the mold.