Clamping mechanism for molding machine

Claim 2

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; and a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position, each Of said straight, angular wedge surfaces terminating in a curved seating recess, the radius of curvature of said curved seating recesses being equal to the radius of curvature of said rollers whereby said rollers are in surface contact with said seating recesses when said first platen has reached said closed position.

Claim 3

In a machine according to claim 1, the improvement wherein each of said wedge surfaces is positioned perpendicular to the longitudinal axis of the corresponding one of said first toggle links when said links are in said closed position.

Claim 4

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen, the other end of each of said first toggle links comprising four extensions thereby forming three generally U-shaped channels therebetween; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of said second toggle links extending into the center U-shaped channels of said first toggle links and being pivotally connected therein to constitute a pair of toggle joints; a roller rotatably secured in each of the remaining U-shaped channels in said first toggle links at each of said toggle joints; and a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position.

Claim 5

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen, the other end of each of said first toggle links comprising four extensions thereby forming three generally U-shaped channels therebetween; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of said second toggle links extending into the center U-shaped channels of said first toggle links and being pivotally connected therein to constitute a pair of toggle joints; a roller rotatably secured in each of the remaining U-shaped channels in said first toggle links at each of said toggle joints; and a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position.

Claim 6

In a machine according to claim 3, the improvement comprising: a pin extending through said extensions, said other end of said second toggle link and said rollers to pivotally connect said elements.

Claim 7

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position; and means for guiding said one end of said piston rod along a substantially linear path to prevent bending thereof, said piston-rod-guiding means comprising: a pair of arms rigidly connected at one ends thereof to said one end of said piston rod; and at least one roller rotatably secured to the other end of each of said arms, said rollers adapted to roll along opposite sides of said fixed supporting frame.

Claim 8

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position; and means for guiding said one end of said piston rod along a substantially linear path to prevent bending thereof, said piston-rod-guiding means comprising: a pair of arms rigidly connected at one ends thereof to said one end of said piston rod; and at least one roller rotatably secured to the other end of each of said arms, said rollers adapted to roll along opposite sides of said fixed supporting frame.

Claim 9

In a machine according to claim 5, the improvement wherein said arms extend in a direction parallel to the plane of motion of said toggle joints.

Claim 10

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toGgle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position; and means for guiding said one end of said piston rod along a substantially linear path to prevent bending thereof, said piston-rod-guiding means comprising: a pair of arms rigidly connected at one ends thereof to said one end of said piston rod; and a pair of vertically disposed grooves in opposite sides of said fixed supporting frame, said arms extending into said grooves whereby the path of said piston rod is guided by said grooves.

Claim 11

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toGgle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position; and means for guiding said one end of said piston rod along a substantially linear path to prevent bending thereof, said piston-rod-guiding means comprising: a pair of arms rigidly connected at one ends thereof to said one end of said piston rod; and a pair of vertically disposed grooves in opposite sides of said fixed supporting frame, said arms extending into said grooves whereby the path of said piston rod is guided by said grooves.

Claim 12

In a machine according to claim 7, the improvement wherein said arms extend in a direction which is perpendicular to the plane of motion of said toggle joints.

Claim 13

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position; and means for guiding said one end of said piston rod along a substantially linear path to prevent bending thereof, said piston-rod-guiding means comprising: a pin extending through said one ends of said second toggle links and said one end of said piston rod; and a pair of vertically disposed grooves in opposite sides of said supporting frame, the opposite ends of said pin extending into said grooves whereby the path of said piston rod is guided by said grooves.

Claim 14

In a machine for molding plastics or other moldable materials wherein a first platen moves along a fixed supporting frame between an open position and a closed position relative to a second platen under the control of a reciprocating piston rod, the improvement comprising: a pair of first toggle links each pivotally connected at one end thereof to said first platen; a pair of second toggle links each pivotally connected at one end thereof to one end of said piston rod, the other ends of each of said first and second toggle links being pivotally connected to each other to constitute a pair of toggle joints; at least one roller rotatably secured at each of said toggle joints; a pair of straight, angular wedge surfaces positioned on opposite sides of said supporting frame, said rollers adapted to contact and roll along said wedge surfaces so as to impart a wedging action to said first platen during movement of said toggle joints, said second toggle links being in alignment when said first platen has reached said closed position; and means for guiding said one end of said piston rod along a substantially linear path to prevent bending thereof, said piston-rod-guiding means comprising: a pin extending through said one ends of said second toggle links and said one end of said piston rod; and a pair of vertically disposed grooves in opposite sides of said supporting frame, the opposite ends of said pin extending into said grooves whereby the path of said piston rod is guided by said grooves.