Abstract
A suction-cup vacuum gripping tool comprising one mounting flange, one suction cup, one vacuum pump, one pressure sensor, one contact detector and one blow-off valve. When the suction cup reaches the workpiece, the suction cup is evacuated by the vacuum pump. 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 suction-cup vacuum gripping tool: one suction cup carried on a mounting flange, fed by a vacuum pump. It is arranged for verifying that the workpiece is held before the arm moves, 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]One suction cup. Each suction cup presents a sealing lip to the workpiece and is evacuated through its own connection. The suction cups are of the flat form.
[0004]One vacuum pump. The pump draws the circuit down mechanically and adds its own mass to the moving assembly.
[0005]One pressure sensor. The pressure sensor taps the line it is placed in and reports the vacuum level in that line. The pressure is measured in the supply line.
[0006]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.
[0007]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 sustained blast. The blow-off pulse is given after set-down.
[0008]The suction cup is carried on the tool side of the mounting flange.
[0009]The vacuum pump is fixed to the tool side of the mounting flange.
[0010]The suction cup is connected to the pump inlet line by a single vacuum line, so that the face is evacuated through that line.
[0011]The pressure sensor is tapped into the line between the vacuum pump and the suction cup and reads the pressure of the whole circuit.
[0012]The contact detector is mounted on the gripping face and reports the moment a workpiece is present against the gripping face.
[0013]The blow-off valve is connected to the circuit at the pump inlet line, so that compressed air can be driven back through the circuit to the face.
[0014]The robot side of the mounting flange is bolted to the robot flange.
[0015]The pump motor is supplied from the electrical supply of the cell.
[0016]The blow-off valve is fed from the compressed air supply of the cell.
[0017]The blow-off valve is switched by the cell controller; the pressure sensor and the contact detector report to the cell controller.
3. Operating sequence and conditions
[0018]
- After the contact detector has detected the workpiece, the vacuum supply is actuated by the cell controller.
[0019]
- When the suction cup reaches the workpiece, the suction cup is evacuated by the vacuum pump.
[0020]
- When the vacuum level exceeds the gripping threshold, a secure grip is signalled by the pressure sensor.
[0021]
- The workpiece may not be lifted unless the pressure sensor signals a secure grip.
[0022]
- After the workpiece has reached the set-down position, the workpiece is blown off by the blow-off valve.
[0023]
- The workpiece is held until the blow-off valve has opened the circuit.
[0024]The cell controller reads the pressure sensor (the common supply line) and the contact detector (on the gripping face) and commands the blow-off valve; no sensor drives an actuator directly.
4. Parameters and operating assumptions
[0025]Parameter values of this embodiment: form of the suction cup: flat (sets the shape of the contact area and the behaviour of the lip on a curved workpiece); material of the suction cup: polyurethane (sets the friction at the lip and the tolerance of the lip to oil and heat); drive medium of the vacuum pump: electric (sets the supply the pump motor needs from the cell); placement of the pressure sensor: in the supply line (sets where in the circuit the reading is taken and what it describes); 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 sustained blast (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).
[0026]The blow-off is a sustained blast: the valve stays open for the whole release so that the face is cleared of dust and the workpiece is pushed positively away.
[0027]Vacuum levels are stated as gauge pressure below atmosphere. A stronger vacuum is a larger pressure difference below atmosphere, and the vacuum level 'exceeds the gripping threshold' when that difference is at least the threshold difference.
5. Provenance and status
[0028]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-10549431-B2, US-11427405-B1, US-2016214812-A1, US-2022339798-A1, US-8132312-B2; their text is not reproduced, and the description above is generated from the structure of the combination.