Transport system for workpieces

#This invention relates to systems for transporting workplaces into and out of an enclosure where workplaces are processed.

#Many machines, including turning machines and milling machines, have protective enclosures, or guards, surrounding a work processing or machining zone. Such enclosures usually have a manually openable door for periodic operator duties. In a fully automatic machine, a work handling device is often employed to speed production time; i.e., the device supplies a rough workpiece to the machine and removes a finished workpiece, at designated intervals in the cycle. The usual way of covering an access opening for parts entering and leaving the enclosure is to provide a door, which is swingable on hinges or is slidable in a track, where the door is powered by an air cylinder, for example. Once incorporated into a guard design, sliding and swinging doors are not easily relocated on a work enclosure because of the space taken by the support structure, and sliding and swinging doors are not easily retrofitted to existing machine guards in the field, when it is desired to add automation. The supporting hinges and tracks for access doors are subject to wear and potential jamming from chips and dirt, and may present a maintenance problem.

#The following invention obviates many of the difficulties inherent in the prior art devices by providing a transport system which utilizes an access door having no pivot joints and no sliding tracks.

#FIG. 1 is a front perspective view, looking at the chuck end of a turning machine headstock.

#FIG. 2 is a rear perspective view, looking at the rear surface of the bulkhead and door of FIG. 1.

#FIG. 3 is a rear elevational view of the door assembly of FIG. 1.

#Referring to the drawings, FIG. 1 shows a turning machine 10 having a headstock 11, rotary spindle 12, and workholding chuck 13. An exemplary turning machine 10 is the AVENGER.RTM. 200T turning center, with an ACRAMATIC.RTM. 850SX CNC (computer numerical control unit--not shown) for automatically controlling machine cycles; both machine and control are available from Cincinnati Milacron Inc., assignee of the present invention.

#The spindle nose and chuck 13 extend through a bulkhead 14, which is a sheet metal wall comprising part of the machine enclosure 15. The enclosure 15 comprises a sheet metal guard 16 surrounding the machining zone; i.e. the interior of the guard constitutes a machining zone, where workpieces are processed. An operator access door 17 is shown retracted to view the interior of the guard 16, where a tool turret 18 is shown in a parked position. A workpiece transporter 19 is stationed on the floor at the rear of the machine headstock 11. The transporter 19 has a hollow fabricated base 20, upon which a pair of linear ways 21,22 support a carriage 23 for linear movement, parallel to the headstock spindle centerline 24. The carriage 23 is driven by a first servomotor 25 mounted to the base 20.

#The carriage 23 has a tubular, cantilevered support arm 26 extending from its rotary spindle 27, and the spindle 27 and support arm 26 are rotatably positioned about the carriage spindle centerline 28 by a second servomotor 29 mounted to the carriage 23. An end plate 30 is affixed to the support arm 26, and the end plate 30 has two workpiece grippers 31 which are used to deliver a rough workpiece 32a to the chuck 13 and to remove a finished workpiece 32b from the chuck 13. The support arm 26 and end plate 30 move the grippers 31 into the machining zone through a keystone-shaped, framed opening 33 in the bulkhead 14. Once the support arm 26 is linearly positioned within the machining zone, the arm 26 is linearly shifted (by the first servomotor 25) and rotatably indexed (by the second servomotor 29) to extract a finished workpiece 32b and insert a rough workpiece 32a.