Abstract
A zoned vacuum gripping tool comprising one mounting flange, three suction cups, one ejector, three isolation valves, three zone branches, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve. The arrangement is a proposed configuration composed from a typed library of mechanism blocks derived from published patents; it has not been constructed.
1. Purpose and arrangement
[0001]This disclosure describes a zoned vacuum gripping tool: three suction cups carried on a mounting flange, fed by an ejector. It is arranged for handling workpieces that do not cover the whole gripping face, cutting part of the circuit while the rest holds vacuum, starting the cycle at the moment of contact and clearing the face at release. One concrete embodiment is described; every connection is stated with the medium it carries, and the operating sequence is given as conditions on named operations.
2. Components, construction and connections
[0002]One mounting flange. The mounting flange carries the whole assembly and presents the bolt pattern that meets the robot.
[0003]Three suction cups. Each suction cup presents a sealing lip to the workpiece and is evacuated through its own connection. The count of three follows from the arrangement: one gripping element per zone branch. The suction cups are of the flat form.
[0004]One ejector. The ejector draws the circuit down by passing compressed air through a nozzle; it has no moving part at the tool and consumes air for as long as it runs. The ejector has three stages.
[0005]Three isolation valves. Each isolation valve sits in the line it controls; closing it cuts that line without disturbing the rest of the circuit. The count of three follows from the arrangement: one valve per zone branch. Isolation is per zone.
[0006]Three zone branches. Each zone branch carries the vacuum of one zone of the face and no other. The count of three follows from the arrangement: one branch per zone. The distribution is divided into three zones, each fed by its own branch.
[0007]One contact detector. The contact detector reports the moment a workpiece is present at the gripping face; its sensing technology is not fixed by this arrangement. The contact detector is mounted on the gripping face.
[0008]One blow-off valve. The blow-off valve drives compressed air back through the circuit to the face, which clears the face instead of waiting for the circuit to refill. The blow-off is a short pulse. The blow-off pulse is given after set-down.
[0009]The suction cups are carried on the tool side of the mounting flange.
[0010]The ejector is fixed to the tool side of the mounting flange.
[0011]The three zone branches are taken from a branch junction on the ejector outlet, so that each branch carries the vacuum of its own zone only.
[0012]One isolation valve is placed in each zone branch, so that closing that valve cuts its zone from the circuit and leaves the other zones under vacuum.
[0013]Each suction cup is connected to its own zone line, one suction cup per zone, and is evacuated through that line.
[0014]The contact detector is mounted on the gripping face and reports the moment a workpiece is present against the gripping face.
[0015]The blow-off valve is connected to the circuit at the ejector outlet, so that compressed air can be driven back through the circuit to the face.
[0016]The robot side of the mounting flange is bolted to the robot flange.
[0017]The ejector is fed from the compressed air supply of the cell.
[0018]The blow-off valve is fed from the compressed air supply of the cell.
[0019]The isolation valves and the blow-off valve are switched by the cell controller; the contact detector reports to the cell controller.
3. Operating sequence and conditions
[0020]
- After the contact detector has detected the workpiece, the vacuum supply is actuated by the cell controller.
[0021]
- When the suction cups reach the workpiece, the suction cups are evacuated by the ejector.
[0022]
- When a zone is not covered by the workpiece, the isolation valve of that zone is closed by the cell controller.
[0023]
- While the isolation valve of that zone is in the open state, the vacuum of a covered zone is maintained by the ejector.
[0024]
- After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve.
[0025]
- The workpiece is held until the blow-off valve has opened the circuit.
[0026]The cell controller reads the contact detector (on the gripping face) and commands the blow-off valve, the isolation valves; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0027]Parameter values of this embodiment: form of the suction cups: flat (sets the shape of the contact area and the behaviour of the lip on a curved workpiece); material of the suction cups: polyurethane (sets the friction at the lip and the tolerance of the lip to oil and heat); stages of the ejector: three (sets the flow drawn at low vacuum and the compressed air consumed while a sealed face is held); control of the isolation valves: per zone (sets which part of the circuit the valve cuts: one branch line on its own or the whole circuit); material of the isolation valves: steel; material of the zone branches: plastic; zones of the zone branches: three (sets how much of the face can be treated separately); placement of the contact detector: on the gripping face (sets where the presence of the workpiece is detected); duration of the blow-off valve: a short pulse (sets how quickly the face clears and how much air each release costs); timing of the blow-off valve: after set-down (sets whether the pulse assists a drop release or clears the face after set-down).
[0028]Which zones the workpiece covers is known to the controller from the workpiece programme; the arrangement provides the valve per zone and the controller decides which valves to close.
[0029]The blow-off is a short pulse: the valve opens for a fraction of a second, long enough to break the seal and clear the face, and closes again.
[0030]A zone whose isolation valve is closed is cut from the common line and does not vent or blow off until its valve opens.
5. Provenance and status
[0031]This document is an original combination composed from a typed library of mechanism blocks. Each block was derived from a published patent and carries typed connection points, the parameters its source states, and its own construction and operating description. The combination described here is proposed and has not been constructed. The published documents behind the blocks used in this arrangement are US-10163334-B1, US-10549431-B2, US-2016214812-A1, US-2022339798-A1, US-8132312-B2, WO-2008134339-A4, WO-2026020244-A1; their text is not reproduced, and the description above is generated from the structure of the combination.