US3905741A — Hydraulic press for molding plastic materials

Claim 1

Independent Claim 286 words

In a hydraulic molding press including: a frame; a stationary platen fixed to said frame to support a first portion of a mold formed of two portions; a movable platen disposed parallel to said first platen and supporting the second portion of said mold, said movable platen being reciprocable in said frame towards and away from said stationary platen to close or open said first and second mold portions with respect to each other; long stroke approach ram means fixed to said frame to actuate said movable platen to opened and closed positions of said mold; a stationary plate having at least one opening therethrough and the plate being fixed to said frame; short stroke clamping ram means having cylinder means attached to said movable platen and having piston rod means extending toward said at least one opening in said stationary plate when said mold has been closed to maintain said mold portions against each other; and locking means operative to block said piston rod means of the clamping ram means with respect to said stationary plate during operation of said clamping ram means; the improvement comprising in said molding press said locking means being carried by the piston rod means, and said at least one opening through said stationary plate being located and of such size that the piston rod means and the locking means and the cylinder means of the corresponding clamping ram means when the locking means is unblocked can pass freely through said at least one opening in the stationary plate and extend on the other side of the plate from said stationary platen during displacement of said movable platen by the approach ram means to fully open position of said mold.

Claim 2

Dependent Claim 286 words

In a hydraulic molding press including: a frame; a stationary platen fixed to said frame to support a first portion of a mold formed of two portions; a movable platen disposed parallel to said first platen and supporting the second portion of said mold, said movable platen being reciprocable in said frame towards and away from said stationary platen to close or open said first and second mold portions with respect to each other; long stroke approach ram means fixed to said frame to actuate said movable platen to opened and closed positions of said mold; a stationary plate having at least one opening therethrough and the plate being fixed to said frame; short stroke clamping ram means having cylinder means attached to said movable platen and having piston rod means extending toward said at least one opening in said stationary plate when said mold has been closed to maintain said mold portions against each other; and locking means operative to block said piston rod means of the clamping ram means with respect to said stationary plate during operation of said clamping ram means; the improvement comprising in said molding press said locking means being carried by the piston rod means, and said at least one opening through said stationary plate being located and of such size that the piston rod means and the locking means and the cylinder means of the corresponding clamping ram means when the locking means is unblocked can pass freely through said at least one opening in the stationary plate and extend on the other side of the plate from said stationary platen during displacement of said movable platen by the approach ram means to fully open position of said mold.

Claim 3

Dependent Claim 50 words

A hydraulic molding press as claimed in claim 1, wherein said at least one opening comprises multiple openings and wherein said clamping ram means comprises multiple clamping rams disposed in parallel relationship for operation between said movable platen and said stationary plate when their piston rod means are locked thereto.

Claim 4

Dependent Claim 95 words

In a hydraulic molding press as claimed in claim 1 said at least one opening through said stationary plate being cross-sectionally elongated in shape with a width greater than the outer diameter of the cylinder means, and said locking means which is carried on said piston rod means comprising an elongated bolt rotatably mounted on the piston rod means, the bolt being passable through the associated opening for at least one angular position of said bolt with respect to said at least one opening but blocking against said stationary plate for any other Angular position.

Claim 5

Dependent Claim 212 words

In a hydraulic molding press as claimed in claim 3: said stationary plate having a side which faces said movable platen to engage and block said bolt; said at least one opening of said stationary plate being of generally rectangular shpae with two long edges and two short edges; said bolt also being of generally rectangular shape with two long edges and two short edges, the distance between the long edges of said bolt forming the width thereof, and said bolt having a given thickness in the vicinity of its short edges; and said stationary plate having on said side thereof abutment means extending along both edges of said at least one opening, said abutment means being spaced from said side of said stationary plate to receive the thickness of said bolt in the vicinity of the short edges thereof, whereby when a bolt is in position to engage said side of said stationary plate, rotation of said bolt through 90* brings the short edges thereof between the long edges of said at least one opening and said abutment means to support the piston rod means of said clamping ram means and render the ram means operative to retract said movable platen in the direction corresponding to the opening of said mold.

Claim 6

Dependent Claim 93 words

In a hydraulic molding press as claimed in claim 1, wherein said clamping ram means comprises multiple clamping rams having piston rods and cylinders, synchronizing means to determine for said multiple clamping rams a uniform rate of relative displacement between their piston rods and cylinders; an individual distributing valve associated with each one of said clamping rams to control same; and comparator means responsive to the difference between the actual relative position of the cylinder and piston rod of each one of said rams and the relative position prescribed by said synchronizing means.

Claim 7

Dependent Claim 145 words

In a hydraulic molding press as claimed in claim 5: each of said clamping rams including a first and a second element rectilinearly movable with respect to each other; said synchronizing means including for each one of said clamping rams: a. an individual servo-motor; b. a first screw-threaded member rotated by said servo-motor, said first screw-threaded member having an axis parallel to the relative displacement of the first and second elements of the associated clamping ram, and being reatined axially with respect to said first element; and said comparator means comprising a second screw-threaded member relatively displaceable upon rotation of said first screw-threaded member, said second screw-threaded member being carried by said second element of said clamping ram, the distributing means associated with said ram being actuated by the linerar displacement of said first screw-threaded member relative to said first element of said clamping rams.

Claim 8

Dependent Claim 185 words

A hydraulic molding press comprising: a frame; a stationary platen fixed to said frame to support the first one of the two portions of a mold; a movable platen to support the second portion of the mold, said movable platen being disposed parallel to said stationary platen and being reciprocable in said frame towards and away from said stationary platen; and at least one ram to actuate said movable platen, said ram including: a. a cylinder having a first and a second end; b. a number of pistons slidable within said cylinder in fluid-tight relation with respect thereto; c. a number of partitions including intermediate partitions disposed between successively adjacent pistons, said partitions being fixed and sealed to said cylinder in fluid-tight relation thereto; d. a common piston rod reciprocably passing in fluid-tight relation through the first end of said cylinder and through successive intermediate partitions, with said pistons being attached to said common rod; e. and means to selectively pressurize spaces within said cylinder, said spaces being defined on one side by one of said pistonS and on the other side by a partition.

Claim 9

Dependent Claim 185 words

A hydraulic molding press comprising: a frame; a stationary platen fixed to said frame to support the first one of the two portions of a mold; a movable platen to support the second portion of the mold, said movable platen being disposed parallel to said stationary platen and being reciprocable in said frame towards and away from said stationary platen; and at least one ram to actuate said movable platen, said ram including: a. a cylinder having a first and a second end; b. a number of pistons slidable within said cylinder in fluid-tight relation with respect thereto; c. a number of partitions including intermediate partitions disposed between successively adjacent pistons, said partitions being fixed and sealed to said cylinder in fluid-tight relation thereto; d. a common piston rod reciprocably passing in fluid-tight relation through the first end of said cylinder and through successive intermediate partitions, with said pistons being attached to said common rod; e. and means to selectively pressurize spaces within said cylinder, said spaces being defined on one side by one of said pistonS and on the other side by a partition.

Claim 10

Dependent Claim 81 words

In a hydraulic molding press as claimed in claim 7, said cylinder comprising an outer casing having an inner cylindrical bore, with said first and second ends of the cylinder being fixed to said casing; and a number of cylindrical sleeves disposed in succession within said bore between said first and second ends, each of said sleeves having a first and a second end; and some at least of said intermediate partitions being secured to the first ends of said sleeves.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-09-15	1979-03-17	1979-09-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-09-15	1983-03-17	1983-09-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-09-15	1987-03-17	1987-09-16	$7700.00	Window Closed / Lapsed

Hydraulic press for molding plastic materials

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