High speed article retrieval system

A retrieval system for rapidly removing articles from a plastic molding machine or other manufacturing process includes two pairs of lightweight non-metallic telescoping retrieval tubes arranged for telescoping motion into and out of an open mold. Each pair of telescoping retrieval tubes is coupled to a pair of slidable bearing tubes. A movable one of each pair of retrieval and bearing tubes is driven in concert by a low inertia cable or other drive system. A fixed one of each of each pair of retrieval and bearing tubes includes longitudinal strips of plastic bearing material.

REFERENCE TO RELATED PATENT 
This application is related to and incorporates by reference the subject 
matter of U.S. Pat. No. 5,234,328. 
BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates generally to article handling apparatus and more 
specifically to an apparatus for rapidly removing molded articles from 
plastic molding machines, as well as articles formed by various other 
manufacturing processes. A number of systems are known in the prior art 
for removing molded articles following ejection of those parts from a 
conventional injection molding machine, for example. Included are simple 
systems in which molded articles are permitted to drop from the mold after 
ejection, labor intensive manual systems, conveyor systems that transport 
the articles after they have been ejected, and more complex mechanical 
grasping and suction systems that serve to remove the ejected articles. 
The prior art manual systems result in contamination of dropped articles 
and the need for additional subsequent handling. The prior art mechanical 
grasping and suction systems are disadvantageous in that most of them 
suffer from slow operating speeds. In today's manufacturing processes, it 
is increasingly important to maximize the output of manufactured articles 
to control the cost of production and thereby maintain a competitive 
position in the marketplace. This need for high output is particularly 
important in the plastic molding industry, for example, where molding 
cycles may be no more than a few seconds. The production rate in this 
industry has been limited by the inability of prior art article handling 
devices to rapidly retrieve molded parts from a mold so that a new molding 
cycle may begin. 
It is therefore a principal object of the present invention to provide a 
retrieval system for rapidly removing articles from a plastic molding 
machine or other manufacturing process to significantly shorten the 
manufacturing cycle time over prior art manufacturing processes that 
employ automated article retrieval systems. The speed advantage afforded 
by the present invention is achieved by realizing acceleration rates on 
the order of 26 G's as compared to acceleration rates in prior art article 
retrieval systems of 6-10 G's. 
This and other objects are accomplished in accordance with the illustrated 
preferred embodiment of the present invention by providing two pairs of 
lightweight non-metallic telescoping retrieval tubes arranged for 
telescoping motion into and out of an open mold. Each pair of telescoping 
retrieval tubes is coupled to a pair of telescoping bearing tubes. The 
retrieval and bearing tubes are driven in concert by a low inertia cable 
drive system. Each of the telescoping pairs of retrieval and bearing tubes 
includes strips of plastic bearing material.

DETAILED DESCRIPTION OF THE INVENTION 
Referring generally to FIG. 1, there is shown an article retrieval system 
100 positioned in relationship to a conventional molding machine 110 such 
that molded articles 114 are automatically rapidly removed from a mold 112 
controlled by molding machine 110 at the completion of each molding cycle. 
The articles 114 so removed may then be oriented and routed for further 
processing, as desired, by an apparatus illustrated generally in FIG. 1 
that does not form part of the present invention. 
Referring now to the detailed pictorial diagrams of FIGS. 2-4, there are 
shown upper and lower telescoping retrieval tube assemblies 40 and 42. 
Upper telescoping retrieval tube assembly 40 comprises a fixed inner tube 
44 and a movable outer tube 46. Similarly, lower telescoping retrieval 
tube assembly 42 comprises a fixed inner tube 48 and a movable outer tube 
50. Associated with and coupled to the upper and lower telescoping 
retrieval tube assemblies 40 and 42 are upper and lower bearing tube 
assemblies 52 and 54. Upper bearing tube assembly 52 comprises a fixed 
inner tube 56 and a movable outer tube 58, while lower bearing tube 
assembly 54 similarly comprises a fixed inner tube 60 and a movable outer 
tube 62. Retrieval tube assemblies 40, 42, as well as bearing tube 
assemblies 52, 54, are preferably fabricated of a non-metallic plastic or 
carbon fiber material to minimize their weight. Most importantly, each of 
the inner tubes 44, 48, 56, and 60 include bearing strips 70, comprising a 
plastic bearing material, such as ultra high molecular weight (UHMW) 
plastic bearing material, for example, on each of the four outer surfaces 
thereof, to act as bearing surfaces over which outer tubes 46, 50, 58, and 
62 slide. Bearing strips 70 may be attached to the inner tubes 44, 48, 56, 
60 by any conventional means, such as pressure sensitive adhesive. 
The outer tubes 46, 50, 54, 58 are driven in concert between predetermined 
first and second stop positions by means of a cable system, for example, 
that generally comprises a servo motor 1, two idler pulleys 2, a drive 
pulley 3, and a cable 8. A belt drive system may be substituted for the 
cable drive system illustrated. If desired, the bearing tube assemblies 
52, 54 may be eliminated, in which case the cable or other drive system 
operates to drive the retrieval tube assemblies 40, 42. 
A number of receivers 11 or other suitable capture devices are mounted on 
outer tubes 46 and 50 in correspondence with the position of the molded 
articles as they are ejected from the mold 112. A vacuum manifold 12, to 
which the inner tubes 44 and 48 are mounted, receives vacuum from a 
conventional external source through a vacuum inlet 16 and is drawn 
through the inner tubes 44 and 48, as illustrated by arrows in FIG. 2. 
Vacuum ports 5 in the outer tubes 46, 50, over which each of the receivers 
11 is mounted, serve to draw molded articles from mold 112. 
The article retrieval system of the present invention is controlled during 
operation as described in detail in the above-referenced U.S. Pat. No. 
5,234,328.