Abstract: The apparatus has a pair of spaced arms hinged at their lower ends to a base. The upper end of each arm supports a jaw which is used to grip the rubber mold. Each arm has a nut pivotably supported between the ends thereof which nut pivots about an axis parallel to the base and perpendicular to the centerline of the nut so that a long bolt, which is threaded in the nut and has its end pivotably anchored to the base, can rigidly support the arms in a substantially upright and variable position. Then by simply rotating each long bolt, the respective arm is made to rotate to change its angle it makes with the vertical.