Plastic article or earthenware shaping or treating: apparatus – Control means responsive to or actuated by means sensing or... – Mold motion or position control
Patent
1997-02-07
1998-09-01
Heitbrink, Tim
Plastic article or earthenware shaping or treating: apparatus
Control means responsive to or actuated by means sensing or...
Mold motion or position control
4254501, 4254512, 425589, 425590, B29C 4580
Patent
active
058008438
DESCRIPTION:
BRIEF SUMMARY
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to an apparatus for injection molding thermoplastic materials, comprising a substantially C-shaped frame which is bent open by the closing force produced by a closing device between the mold halves carried respectively by a stationary and a movable mold mounting plate, wherein the angle between at least one mold mounting plate and the associated limb of the frame is variable.
Several apparatuses of that kind have been proposed in recent times (see for example DE-U 92 12 480.1). In that respect the pivotal mounting of at least one of the mold mounting plates serves the purpose of making the orientation of that plate independent of deformation phenomena in respect of the associated vertical limb of the machine frame, as can occur in relation to machines without a connecting beam member. If each mold mounting plate has a pivot, then when the closing pressure is applied the two mold mounting plates and the mold halves secured thereto retain their orientation in space while the limbs of the frame bend outwardly. A particularly simple structure is shown in EP-B2 311 133 in which only the movable mold mounting plate is mounted tiltably. In this case the condition of plate parallelism is achieved by virtue of the fact that the movable mold mounting plate accompanies the stationary mold mounting plate in its pivotal movement. The angle through which the pivot pivots thus corresponds to the sum of the pivotal movements of the two vertical limbs of the machine frame.
In conventional machines the movable mold mounting plate is pressed during the procedure by spring force against an abutment which vertically orients the plate so that the two mold halves are already in an exactly parallel position when they meet each other. The moment applied to the pivot by the weight of the movable mold mounting plate is therefore at least compensated by the spring. If then the frame experiences deformation when the closing force is applied, a moment must be applied to the pivot, which moment moves the pivot. In that arrangement, the structure of the pivot is not an important consideration: if it involves a pin or the like which is movable in a bearing shell, the bearing friction has to be overcome, while if the frame and the mold mounting plates are connected by a deformable intermediate member, work has to be done against the elasticity thereof. In known apparatuses there are only passive machine elements such as springs and immovable abutments in the pivot region so that the additional moment for producing the pivotal movement upon deformation of the machine frame must be produced by the mold initially being compressed to a greater degree by the closing force in the lower region than in the upper region. That admittedly makes it unnecessary to have a separate control as the same closing force which deforms the frame also turns the pivot, but the movement only begins when there is a given minimum degree of deformation of the machine frame and the mold.
SUMMARY OF THE INVENTION
The object of the present invention is deliberately and specifically to influence the angle between the mold mounting plate and the frame, in which respect the properties of the mold are to be of minimum significance.
That object is attained in that there is provided a controllable means, by the actuation of which a torque increasing the angle between the mold mounting plate and the frame is applied to or rendered operative on the mold mounting plate.
In the simplest case the application of an additional torque upon an increase in the closing force is effected by release of an abutment which during the movement of the mold mounting plate has prevented it from turning under the influence of its own weight. That means that the weight of the plate becomes operative in the sense of moving the pivot.
In a further configuration of the invention it can be provided that the means for influencing the plate orientation is in the form of a setting means which is provided with a drive and which actively turns
REFERENCES:
patent: 5249951 (1993-10-01), Leonhartsberger et al.
patent: 5354196 (1994-10-01), Ziv-Av
patent: 5478231 (1995-12-01), Hehl
patent: 5556656 (1996-09-01), Lampl et al.
patent: 5633024 (1997-05-01), Ziv-Av
Kappelmuller Werner
Leonhartsberger Heinz
Engel Maschinenbau Gesellschaft m.b.H.
Heitbrink Tim
LandOfFree
Apparatus for injection molding plastic material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for injection molding plastic material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for injection molding plastic material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-267530