---
publication_id: "OT-2026-000011922"
title: "Three finger pneumatic gripper, stripped after set-down"
published_at: "2026-09-17T08:13:00.631271Z"
canonical_url: "https://opentechnical.org/p/OT-2026-000011922"
categories:
  - "robotics-automation/end-effectors/mechanical-grippers"
  - "sensors-controls-machine-vision/position-and-presence-sensing"
keywords:
  - "mechanical gripper"
  - "mounting flange"
  - "gripper finger"
  - "contact detector"
  - "separating element"
  - "compressed air supply"
  - "contact sensing"
  - "mechanical gripping"
  - "release control"
---

# Three finger pneumatic gripper, stripped after set-down

## Abstract

A mechanical finger gripper comprising one mounting flange, three gripper fingers, one contact detector and one separating element. When the gripper reaches the gripping position, the gripper fingers are closed by the pneumatic actuator. After the gripper fingers have been opened, the workpiece is released by the separating element. 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 mechanical finger gripper: three gripper fingers carried on a mounting flange. It is arranged for starting the cycle at the moment of contact and separating a workpiece that stays on the face. 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 gripper fingers.** The fingers close onto the workpiece and hold it by form closure; they need access to opposed surfaces of the workpiece. The count of three follows from the arrangement: the count is the one the source module states. The fingers are driven by a pneumatic actuator.

[0004] **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 frame.

[0005] **One separating element.** The separating element acts on the workpiece directly, so release does not depend on the holding mechanism alone.

[0006] The gripper fingers are carried on the tool side of the mounting flange.

[0007] The contact detector is mounted on the frame and reports the moment a workpiece is present between the fingers.

[0008] The separating element acts on the workpiece held at the gripper fingers and pushes it clear of the face.

[0009] The robot side of the mounting flange is bolted to the robot flange.

[0010] The pneumatic finger actuator is fed from the compressed air supply of the cell.

[0011] The separating element is driven from the compressed air supply of the cell.

[0012] The separating element is switched by the cell controller; the contact detector reports to the cell controller.

## 3. Operating sequence and conditions

- After the contact detector has detected the workpiece, the closing cycle is actuated by the cell controller.

- When the gripper reaches the gripping position, the gripper fingers are closed by the pneumatic actuator.

- While the gripper fingers are in the closed state, the workpiece is clamped by the gripper fingers.

- After the workpiece has reached the set-down position, the gripper fingers are opened by the pneumatic actuator.

- After the gripper fingers have been opened, the workpiece is released by the separating element.

[0018] The cell controller reads the contact detector (on the frame) and commands the gripper fingers, the separating element; no sensor drives an actuator directly.

## 4. Parameters and operating assumptions

[0019] Parameter values of this embodiment: drive medium of the gripper fingers: pneumatic (sets which supply the cell has to provide to the actuator and how the closing force is set); placement of the contact detector: on the frame (sets where the presence of the workpiece is detected); timing of the separating element: after set-down (sets when the separating element acts relative to set-down).

## 5. Provenance and status

[0020] 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-2022339798-A1, US-2023381975-A1, US-8043071-B2; their text is not reproduced, and the description above is generated from the structure of the combination.