1. Field of the Invention
The present invention relates generally to disk removing devices for use as attachments to injection molding apparatus for producing disks, and more particularly to an improved disk removing device for removing a molded disk from an injection mold unit.
2. Description of the Related Art
FIG. 5 is a schematic perspective view showing a typical example of a conventional disk removing device, which is particularly explanatory of basic operational principles of the disk removing device. Disk 103 is formed into a predetermined shape by an injection mold unit, i.e. between fixed and movable mold members (i.e., mold halves) 101 and 102, of an injection molding apparatus. To remove or take out the thus-molded disk 103 from the injection mold unit, the movable mold member 102 is first retracted in a direction of arrow {circle around (1)}, then a pivotable disk pickup arm 104 is inserted between the fixed mold member 101 and the retracted movable mold member 102, and then a suction cup 105, secured at the distal end of the arm 104, is pressed against the molded disk 103. Once the injection-molded disk 103 is completely grasped by the suction cup 105, the disk pickup arm 104 with the disk 103 firmly grasped by the suction cup 105 is horizontally displaced away from the movable mold member 102 as denoted by arrow {circle around (2)} and then caused to pivotally move as denoted by arrow {circle around (3)}, so that the disk 103 is transferred via the arm 104 over to an appropriate position outside the injection mold unit. Note that the above-mentioned horizontal displacement of the disk pickup arm 104 in the arrow {circle around (2)} direction is necessary for disengaging the molded disk 103 from the movable mold member 102 without the disk 103 being scratched or damaged otherwise by the mold member 102. To perform such disk removing operations, the conventional disk removing device includes a rotary motor 110 that is mounted on a motor base 111 for causing the disk pickup arm 104 to pivotally move in the arrow {circle around (3)} direction. The motor base 111 is placed on a pair of rails 112 in such a manner that the motor base 111 can horizontally slide along the rails 112 by means of a feed screw 113 and a feed motor 114 both provided alongside the rails 112. More specifically, the horizontal displacement of the disk pickup arm 104 in the arrow {circle around (2)} direction is carried out by activation of the feed motor 114, and the subsequent pivotal movement of the disk pickup arm 104 is performed by activation of the rotary motor 110.
As apparent from the illustrated example of FIG. 5, the rails 112, motor base 111, feed screw 113, feed motor 114 and rotary motor 110 are all essential for the conventional disk removing device, which would unavoidably lead to increases in the number of the essential component parts, size and necessary installing space of the disk removing device. As a result, it was heretofore difficult to reduce the overall cost and size of the injection molding apparatus to which the disk removing device is attached.
It is accordingly an object of the present invention to provide a disk removing device which has a reduced size and thus can be installed in a small installing space.
In order to accomplish the above-mentioned object, the present invention provides a disk removing device for removing or taking out, from an injection mold unit, a disk molded by the injection mold unit, which comprises: a disk pickup arm for firmly holding or grasping the disk at a tip end portion of the disk pickup arm; an arm support shaft having the disk pickup arm at a distal end portion thereof; a bearing member for supporting the arm support shaft for axial sliding movement and rotation relative to the bearing member; a rotary motor for rotating the bearing member about an axis of the arm support shaft; and axial drive means for linearly moving the arm support shaft in an axial direction of the arm support shaft. Here, the arm support shaft is provided to extend through the rotary motor so as to position, or operatively connect, the rotary motor and axial drive means in series with each other along the axial direction of the arm support shaft disk. Thus, the disk removing device of the present invention can operate as a uniaxial drive device for removing the molded disk from the injection mold unit.
In the present invention, the molded disk is removed or taken out from the injection mold unit that comprises, for example, two mold members (mold haves), by first displacing the disk pickup arm away from one of the mold members by means of the axial drive means and then causing the disk pickup arm to pivotally move via the arm support shaft by means of the rotary motor. The arm support shaft extends through the rotary motor to be coupled, at the other end remote from the disk pickup arm, to the axial drive means, and thus the rotary motor and axial drive means are operatively connected in series with each other via the support shaft. This way, the inventive disk removing device can operate as a uniaxial drive device. The uniaxial drive arrangement of the invention can significantly reduce the necessary operating space and installing space of the disk removing device, so that the injection molding apparatus, to which the disk removing device is attached, can be effectively reduced in overall size.
In one preferred implementation, the axial drive means is a linear motor which generates thrust force electrically. Because the linear motor requires no mechanic gear or ball, there is no need to worry about lubrication, which can greatly facilitate maintenance and inspection of the axial drive means. Further, the linear motor, i.e. electric-type axial drive means having no mechanical component part, can be made smaller in size than mechanical-type axial drive means.
It is preferable that the rotation of the arm support shaft be by way of a planetary-gear-type speed reduction mechanism, because the above-mentioned rotary motor can be prevented from being subjected to excessive loads when causing the disk pickup arm to pivotally move via the arm support shaft.
Further, the arm support shaft is preferably coupled to a linear shaft of the axial drive means via a shaft coupling. It is preferable that the shaft coupling have a non-rotatable coupling case, the arm support shaft be rotatably connected to the coupling case via bearings and the linear shaft be connected directly to the coupling case, because the linear shaft in this case is allowed to only move linearly with no rotation.