Mold clamping mechanism for molding machine

Claim 2

A mold clamping mechanism for a molding machine comprising a longitudinally reciprocating cylinder, a plurality of wedges having an oblique surface connected through links to a movable metal member wherein a difference in operational speed of the wedges relative to each other causes movement of said movable metal member, each wedge being capable of reciprocal movement perpendicularly towards and away from the axis of said cylinder, one end of said cylinder being provided with at least one oblique surface extending at an angle complementary to each angle of the oblIque surface of said wedges, means for alternately reciprocating said cylinder towards and away from a mold clamping position, hydraulic actuating means, including a connecting rod for each wedge, said connecting rod being hinged to allow pivotal movement between the actuating means and each wedge, for forcing each wedge towards said axis of said reciprocable cylinder when said cylinder approaches the mold clamping position and for continuing to force each wedge towards said axis so that each of said oblique surfaces engages the corresponding oblique surface of the moving cylinder, and means to detect movement of said movable metal member and to compensate for said movement whereby the operational speed of said wedges is controlled to minimize differences therebetween, whereby the wedge effect caused by said engagement generates a force which is utilized as the clamping force for the mold.

Claim 3

A mold clamping mechanism for a molding machine according to claim 1 wherein said means to detect movement of said movable metal member and to compensate for such movement includes at least one selector valve and means attached to said movable metal member and movable therewith to actuate said selector valves as necessary to adjust the hydraulic pressure of forcing said wedges into clamping position to equalize forward movement of said wedges.

Claim 4

A mold clamping mechanism for a molding machine comprising a tie bar frame, a hollow cylinder longitudinally reciprocating in said frame having a pair of oblique surfaces at one end thereof, a movable plate fixed to the other end of said cylinder and slidably received in said frame, at least one stationary plate disposed adjacent the end of said frame closest said one end of said cylinder for guiding the movement of said cylinder, a stationary mounting means extending axially away from said end of said frame and slidably receiving said cylinder, stationary mounting means, hydraulic means associated with said piston means and said cylinder means for longitudinally displacing said cylinder means relative to said piston means towards and away from a mold clamping position, a pair of wedges disposed on opposite sides of said cylinder adjacent said end of said frame, said wedges each having an oblique surface complementary to one of said oblique surfaces of said cylinder and being adapted for reciprocal movement towards and away from the aixs of said cylinder, hydraulic actuating means, including a hydraulic driven reciprocating piston, a connection rod fixed to said piston and hingedly connected to the corresponding wedge to permit pivotal movement between said connecting rod and said wedge, for forcing said wedges towards said axis of said cylinder when said cylinder approaches the mold clamping position and for continuing to force said wedges towards said axis so that the oblique surfaces of said wedges engage the corresponding oblique surfaces of the moving cylinder, switch means for actuating said hydraulic actuating means, a movable metal member connected through links to said wedges, said movable metal member being adapted to actuate said switching means to compensate for differences in the operational speed of said wedges, said links consisting of a pair of levers pivotally connected at one end to a common point on a longitudinally slidable member and at the other end to the respective wedges, said longitudinally slidable member being slidably disposed in a vertically movable member having a pair of ends adapted to engage said switch means to maintain a substantially constant operational speed of the wedges, whereby the wedge effect caused by said engagement generates a force which is utilized as the clamping force for the mold.

Claim 5

A mold clamping mechanism for a molding machine comprising a tie bar frame, a hollow cylinder longitudinally reciprocating in said frame having a pair of oblique surfaces at one end thereof, a movable plate fixed to the other end of said cylinder and slidably received in said frame, at least one stationary plate disposed adjacent the end of said frame closest said one end of said cylinder for guiding the movement of said cylinder, a stationary mounting means extending axially away from said end of said frame and slidably receiving said cylinder, stationary mounting means, hydraulic means associated with said piston means and said cylinder means for longitudinally displacing said cylinder means relative to said piston means towards and away from a mold clamping position, a pair of wedges disposed on opposite sides of said cylinder adjacent said end of said frame, said wedges each having an oblique surface complementary to one of said oblique surfaces of said cylinder and being adapted for reciprocal movement towards and away from the aixs of said cylinder, hydraulic actuating means, including a hydraulic driven reciprocating piston, a connection rod fixed to said piston and hingedly connected to the corresponding wedge to permit pivotal movement between said connecting rod and said wedge, for forcing said wedges towards said axis of said cylinder when said cylinder approaches the mold clamping position and for continuing to force said wedges towards said axis so that the oblique surfaces of said wedges engage the corresponding oblique surfaces of the moving cylinder, switch means for actuating said hydraulic actuating means, a movable metal member connected through links to said wedges, said movable metal member being adapted to actuate said switching means to compensate for differences in the operational speed of said wedges, said links consisting of a pair of levers pivotally connected at one end to a common point on a longitudinally slidable member and at the other end to the respective wedges, said longitudinally slidable member being slidably disposed in a vertically movable member having a pair of ends adapted to engage said switch means to maintain a substantially constant operational speed of the wedges, whereby the wedge effect caused by said engagement generates a force which is utilized as the clamping force for the mold.