---
publication_id: "OT-2026-000007828"
title: "Two finger pneumatic gripper, on a tool changer"
published_at: "2026-09-17T08:10:14.564317Z"
canonical_url: "https://opentechnical.org/p/OT-2026-000007828"
categories:
  - "robotics-automation/end-effectors/mechanical-grippers"
  - "sensors-controls-machine-vision/position-and-presence-sensing"
  - "robotics-automation/end-effectors/tool-changers"
keywords:
  - "mechanical gripper"
  - "tool-change interface"
  - "gripper finger"
  - "contact detector"
  - "compressed air supply"
  - "contact sensing"
  - "mechanical gripping"
  - "tool changing"
---

# Two finger pneumatic gripper, on a tool changer

## Abstract

A mechanical finger gripper comprising one tool-change interface, two gripper fingers and one contact detector. When the gripper reaches the gripping position, the gripper fingers are closed by the pneumatic actuator. 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: two gripper fingers carried on a tool-change interface. It is arranged for starting the cycle at the moment of contact and exchanging the tool without rewiring the cell. 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 tool-change interface.** The tool-change interface splits the tool into a robot side and a tool side, so the tool can be exchanged without dismantling it. The tool-change interface has a pneumatic lock.

[0003] **Two 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 two 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] The gripper fingers are carried on the tool side of the tool-change interface.

[0006] The contact detector is mounted on the frame and reports the moment a workpiece is present between the fingers.

[0007] The robot side of the tool-change interface is bolted to the robot flange.

[0008] The pneumatic finger actuator is fed from the compressed air supply of the cell.

[0009] The locking piston of the tool-change interface is fed from the compressed air supply of the cell.

[0010] The lock of the tool-change interface 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.

[0015] The cell controller reads the contact detector (on the frame) and commands the gripper fingers, the tool-change interface; no sensor drives an actuator directly.

## 4. Parameters and operating assumptions

[0016] Parameter values of this embodiment: locking of the tool-change interface: pneumatic (sets what has to be present at the interface for the tool to stay attached); 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).

[0017] The lock is engaged by compressed air acting on the locking piston and is held only while that air pressure is applied; what the lock does on loss of air pressure is not fixed by this arrangement.

## 5. Provenance and status

[0018] 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-11858125-B2, US-2022339798-A1, US-2023381975-A1; their text is not reproduced, and the description above is generated from the structure of the combination.

## 6. Correction notice

[0019] This publication supersedes OT-2026-000003506, whose text described this arrangement with defects recorded in the quality register at https://opentechnical.org/qa/. The earlier publication is unchanged and remains public. Changes made to reach a consistent configuration: pump removed: a mechanical fingers carries no vacuum circuit; the same corrected configuration also replaces OT-2026-000005262.