Abstract
An end effector for vacuum end-of-arm tooling for robotic material handling is described. The tool comprises a mounting flange (10), a suction cup (12), a ejector (14), a contact detector (16). The arrangement addresses choosing where the vacuum comes from, where an ejector spends compressed air continuously while a pump adds mass at the tool and a plant line couples every tool on the site together. The description covers which source feeds the circuit, what it needs in turn, and what that choice fixes about the rest of the tool. Every connection is stated with the medium it carries, and the operating sequence is given as conditions on named operations.
1. Technical Field
[0001]This disclosure relates to vacuum end-of-arm tooling for robotic material handling. It concerns the arrangement of a gripping interface, the supply that feeds it, the distribution and control between them, and the sequence in which those parts act on a workpiece. FIG. 1 shows the arrangement as a block diagram with the reference numerals used throughout this description.
2. Technical Context
[0002]The arrangement addresses choosing where the vacuum comes from. The difficulty is that an ejector spends compressed air continuously while a pump adds mass at the tool and a plant line couples every tool on the site together. A tool that does not address it is still usable on a narrow range of workpieces, and the cost appears as cycle time, dropped parts or air consumption rather than as an outright failure. What follows covers which source feeds the circuit, what it needs in turn, and what that choice fixes about the rest of the tool.
3. System Overview
[0003]The tool comprises the mounting flange (10), the suction cup (12), the ejector (14), the contact detector (16). FIG. 1 shows how these blocks are connected and which medium each connection carries. The blocks are not interchangeable by name: a connection is made only where one block offers a medium that another needs, and each connection below is stated together with the medium it carries.
[0004]FIG. 2 shows elevation of the gripping face on its mounting.
[0005]
- The mounting flange is bolted to the robot flange (10).
[0006]
- Each suction cup is connected to the ejector by a vacuum line, so that the cup face is evacuated through that line (12).
[0007]
- Each suction cup is mounted on the mounting flange (12).
[0008]
- Compressed air is fed to the ejector from the compressed air supply of the cell (14).
[0009]
- The detector watches the suction cups and reports when a workpiece is present at that face (16).
4. Components
[0010]Mounting Flange (10). The mounting flange (10) is provided once in this arrangement. The flange carries the whole assembly and presents the bolt pattern that meets the robot.
[0011]Suction Cup (12). The suction cup (12) is provided once in this arrangement. Each cup presents a sealing lip to the workpiece and is evacuated through its own connection. The cups are of the oval form. The cups are made of rubber.
[0012]Ejector (14). The ejector (14) is provided once in this arrangement. The ejector draws the circuit down by passing compressed air through a nozzle, so it needs no moving part at the tool. The ejector is built with 3 stages.
[0013]Contact Detector (16). The contact detector (16) is provided once in this arrangement. The detector watches the face and reports the moment a workpiece is present against it. The detector is placed on the gripping face.
5. Operation
[0014]The operating sequence is given as conditions on named operations. Each condition names the event it depends on and the operation it governs, so the order of events is explicit rather than implied by the order of the sentences. FIG. 2 shows the gripping face referred to in these steps. The tool is presented to the workpiece square to the face, and the numbered operations below are what the arrangement does from that point.
[0015]
- When the suction cups seal the workpiece, the suction cups are evacuated by the ejector.
[0016]
- After the contact detector has detected the workpiece, the vacuum supply is actuated.
[0017]An operation whose condition is not met does not run. A condition that is stated with UNLESS holds except while its event is true, and one stated with UNTIL ends the operation at the moment its event becomes true. With the workpiece released, the tool returns to the pick position and the cycle repeats.
6. Example Embodiments
[0018]In one embodiment the gripping face carries 1 suction cups on a common mounting, fed as shown in FIG. 1, and the tool is presented to the workpiece square to the face. In a second embodiment the same face is arranged in two rows so that a long workpiece is supported at both ends, with the connections of FIG. 1 unchanged. In a third embodiment the face is built at half the pitch and the number of suction cups is doubled for the same envelope, which suits a workpiece that is lighter but less rigid.
7. Alternative Configurations
[0019]The gripping face may instead use a flat cup, which is stiffer laterally but needs the face and the workpiece to meet squarely. The gripping face may instead use an array of discrete cups, which concentrates the holding force at the lips and needs a sealing surface. A gripping face of this kind may also be replaced by fingers closing on the workpiece, which removes the air circuit entirely and requires access to two opposed surfaces of the workpiece. The ejector may be replaced by a pump at the tool, which stops the continuous air draw and adds mass to the moving assembly, or by a connection to a plant vacuum line, which removes the generator from the tool and couples the tool to the rest of the site. An isolation valve may be added in the line to each zone, which allows one part of the face to be cut from the circuit while the rest holds its vacuum.
8. Parameter Variations
[0020]Each parameter below is stated with what it changes in the arrangement. The form of the suction cup is oval in the arrangement described; varying it changes the contact area and the behaviour of the lip on a curved workpiece. The material of the suction cup is rubber in the arrangement described; varying it changes the friction at the lip and the tolerance of the face to oil and heat. The stages of the ejector is 3 in the arrangement described; varying it changes the flow drawn at low vacuum and the air consumed to hold a sealed face. The placement of the contact detector is on the gripping face in the arrangement described; varying it changes whether contact is reported for the face as a whole or for one part of it.
9. Additional Implementations
[0021]A pressure sensor may be tapped into the circuit so that the state of the grip is observable, and the motion that follows the grip may be made conditional on the level it reports. The whole assembly may be carried on a tool-change interface so that it can be exchanged between jobs without dismantling the tool. A separating element may be added so that a workpiece which follows the face upwards after release is pushed off positively. The face may be divided into zones, each fed by its own branch, so that a workpiece covering part of the face is handled without the uncovered part being held under vacuum. The arrangement may be duplicated on one mounting so that two workpieces are handled in one cycle, with the distribution fed from a common inlet and each face controlled on its own.
10. Provenance and method
[0022]This document is an original combination composed from a typed library of mechanism blocks. Each block was derived from the published patent literature and carries typed connection points, the parameters its source states, and its own construction and operating description. The combination described here is proposed rather than taken from any one source, and it is not asserted to have been constructed. The published documents behind the blocks used in this arrangement are US-10549431-B2, US-2016214812-A1, US-2022339798-A1, WO-2008134339-A4. Their text is not reproduced here; the description above is generated from the structure of the combination.
11. Figures
