Device for stroke limitation on hydraulically displaced mold carrier units on injection molds

Claim 2

A stroke-limiting device for a hydraulically displaced actuating piston in a mold-carrying unit of an injection-molding machine, comprising: an abutment element which is adjustable in an infinitely variable manner on an adjusting device arranged in the axial direction of the actuating piston of the mold-carrying unit and which, by cooperating with the actuation piston, limits the stroke end position thereof; characterized in that the abutment element is designed to be displaceable, together with its adjusting device into an axial blind aperture in the actuating piston; further characterized in that the abutment element is a screw-threaded sleeve which is adjustaBle along an adjusting thread and which carries at its end remote from the actuating piston an abutment flange cooperating with the annular face of the inner end of the actuating piston; still further characterized in that said adjusting thread contains a stationary screw-threaded tube which is open at its end face in the direction towards the actuating piston and on which said screwthreaded sleeve is screwed by means of an internal screw thread, the inner space of said screw-threaded tube being hydraulically connected with a pressure chamber beyond said annular face.

Claim 3

A device according to claim 1, characterized in that a nonreturn valve is provided which blocks the throughflow of fluid from said inner space of said screw-threaded tube into said pressure chamber beyond said annular face.

Claim 4

A device according to claim 2, characterized in that the diameter of said screw-threaded sleeve, at least over a portion of its length, is so adapted to the zone of said blind aperture adjacent said annular face that, in the mold-open position of the piston, a narrow annular gap is formed between said screw-threaded sleeve and said blind aperture.

Claim 5

A device according to claim 3, characterized in that said screw-threaded sleeve has a threadless prolongation which engages said stationary screw-threaded tube in spaced relationship and in sleevelike manner, and which projects at its end beyond the end of said screw-threaded tube and is formed with a longitudinal groove in which a drive dog is slidably disposed, a spindle being provided on which said drive dog is mounted and which, upon rotation, rotates said abutment element for varying its position along said screw-threaded sleeve.

Claim 6

A device according to claim 3, characterized in that a spindle is provided extending from the exterior of said mold-carrying unit through said stationary screw-threaded element and beyond the inner end thereof, and a slidable and nonrotatable connection is provided between said spindle and said abutment element whereby rotation imparted to said spindle, exterior of said mold-carrying unit, effects rotation of said abutment element for varying its position along said screw-threaded sleeve.

Claim 7

A stroke-limiting device for a hydraulically displaced actuating piston that has a first face and a second face to which an axial, piston rod is secured and that is a part of a mold-carrying unit of an injection molding machine comprising: a cylinder including an axial bore in which the actuating piston is adapted to reciprocally move during operation of the mold-carrying unit; wall means positioned across the end of the cylinder adjacent to the first face of the actuating piston; an adjusting device disposed at least in part within said axial bore; an axial, blind aperture in the first face of the actuating piston, said blind aperture being of sufficient size to receive therein at least a portion of the part of the adjusting device disposed within the axial bore; and an abutment element which is adjustable in an infinitely variable manner on the adjusting device in a direction substantially parallel with the longitudinal central axis of the cylinder and which has a dimension, in a plane substantially parallel to the plane of the first face of the actuating piston, greater than the transverse dimension of said blind aperture, the abutment element, the adjusting device and said blind aperture being arranged so that the abutment element cooperates with the actuating piston to limit the stroke end position thereof when the actuating piston is moving forward the wall means.

Claim 8

A stroke-limiting device for a hydraulically displaced actuating piston that has a first face and a second face to which an axial, piston rod is secured and that is a part of a mold-carrying unit of an injection molding machine comprising: a cylinder including an axial bore in which the actuating piston is adapted to reciprocally move during operation of the mold-carrying unit; wall means positioned across the end of the cylinder adjacent to the first face of the actuating piston; an adjusting device disposed at least in part within said axial bore; an axial, blind aperture in the first face of the actuating piston, said blind aperture being of sufficient size to receive therein at least a portion of the part of the adjusting device disposed within the axial bore; and an abutment element which is adjustable in an infinitely variable manner on the adjusting device in a direction substantially parallel with the longitudinal central axis of the cylinder and which has a dimension, in a plane substantially parallel to the plane of the first face of the actuating piston, greater than the transverse dimension of said blind aperture, the abutment element, the adjusting device and said blind aperture being arranged so that the abutment element cooperates with the actuating piston to limit the stroke end position thereof when the actuating piston is moving forward the wall means.

Claim 9

A device according to claim 6, wherein the adjusting device is supported by the wall means; and wherein at least the portion of the adjusting device is disposed in a direction parallel with the longitudinal central axis of the cylinder.

Claim 10

A device according to claim 7, wherein the abutment element includes a continuous annular surface which faces the first face of the actuating piston, which is disposed in a plane parallEl to the plane of the first face of the actuating piston and which is adapted to come into contact with the first face of the actuating piston; and wherein the transverse dimension of the portion of the adjusting device is selected, with respect to outer dimension of said blind aperture, so that in the mold open position of the actuating piston, a narrow annular gap is formed between the portion of the adjusting device and said blind aperture.