Sealed Type Three-Piece Manipulator is an advanced version of MSM. It is modular in design such that its slave arm can be remotely assembled and disassembled in the hot cell. Unique feature of the manipulator is its sealed construction, which provides total isolation of the cell atmosphere from the outside atmosphere. The master arm and the slave arm can be removed or installed on the through tube without breaking integrity of the cell and prevents the leakage of contamination from hot cell to outside. The sealing integrity is maintained even after the removal of the master arm or the slave arm. Three electrically powered motions are provided on the major joints of the manipulator to enhance the range of the equipment.

Features

• Sealed Through Tube
• Detachable Master and Slave Arms
• Can be remotely assembled and disassembled
• Counterbalancing
• Motorized Indexing Motions and control

Motion transmission  

Within the master and slave arms, cables are used for motion transmission. Any motion on the master is converted to rotary motion with the help of cables, pulleys and rope drums. The motions are then transmitted from the master to the slave side with the help of rotary shafts in the Through Tube.

Specifications

The manipulator has 20 kg load carrying capacity. The slave arm has a reach of 3.3 m from its shoulder joint.

Application

Remote handling of radioactive materials in hot cells

Introduction  

A three-piece master-slave manipulator (TPM) consists of three distinct and easily separable assemblies: the master arm, the through-tube and the slave arm. The unique feature of 3-piece construction is that, its slave arm can be remotely replaced in the hot cell. This modularity reduces installation and maintenance time. Unlike other Master Slave Manipulators (MSMs), TPM uses parallel rotating shafts for power transmission, along the through-tube. This feature is effectively used in indigenous TPM to provide sealing and shielding across the cell wall. 

A through tube passes through a thick concrete wall shielding, separating hot cell and the operating area. It connects the master and slave arms. Lead glass shielding window is used for viewing the hot cell from outside. From the operating area, operator moves the handgrip of the master and the motion is reproduced on the tong of the slave in the remote area. Sealed Type Three-Piece Manipulator is an advanced version of MSM. 

Salient Features

TPM is modular in design such that its slave arm can be remotely assembled and disassembled in the hot cell. Because of its sealed construction, it provides total isolation of the cell atmosphere from the outside atmosphere. The master arm and the slave arm can be removed or installed on the through tube without breaking integrity of the cell. Three electrically powered motions are provided on the major joints of the manipulator to enhance the range of the equipment. Another unique feature of TPM is extended balancing, which will balance its joints in their extended positions also. 

Manipulator Motions  

The manipulator can perform seven manual motions namely X, Y, Z, Azimuth Rotation, Twist Rotation, Elevation Rotation, Squeeze and three electrically driven motions. X motion is the left-right swing motion of the arms about the axis of the through tube in a plane parallel to the cell wall. Y motion is the rotation of arm about the shoulder joint of the manipulator. Z motion is the up and down motion of the telescopic boom tubes. Wrist joint of the manipulator gives the Twist rotation and Elevation rotation to the end effector. The wrists on both master and slave sides are identical and detachable. Azimuth motion is achieved by rotating the master boom and transmitting the same rotary motion to the slave boom. Squeeze motion is affected by the pistol grip on the master side which remotely operates Tong on the slave side.

Motion Transmission

Within the master and slave arms, cables are used for motion transmission. Any motion on the master is converted to rotary motion with the help of cables, pulleys and rope drums. The motions are then transmitted from the master to the slave side with the help of rotary shafts in the Through Tube.

Specifications

The manipulator is designed for 20 kg load carrying capacity. The slave arm has a reach of 3.3 m from its shoulder joint.

Application

Remote handling in radioactive cells

Infrastructure

1. Manufacturing Processes Involved

Most of the parts used in the manipulators are of Stainless Steels (SS-304, SS-410 and 17-4 PH) and Aluminium Alloys (Al-6061-T6, Al-7075-T6, and Al-LM-11). The job is assembly intensive. It involves assembly of large number of fabricated parts, ball bearings, gears, metallic wire ropes, metal tapes, clutch wire, fasteners etc. The following are the manufacturing processes involved in making the manipulator :

• Machining: Turning, Milling, Broaching, Drilling, Grinding, Tapping
• Spur Gear and Bevel Gear Manufacture: Gear Generation, Grinding 
• Casting of Al- LM-11, Lead
• Heat Treatment of SS-410, 17-4 PH, Al-LM-11
• Anodizing, Cadmium Plating, Hard Chrome Plating
• Welding of SS-304 (TIG Welding)
• Crimping and Brazing of SS wire ropes
• Electrical: Wiring, Soldering, etc.
• Inspection of parts and sub-assemblies

2. Machine Tools/ Equipments needed for Manufacture

• Lathe, milling machine, drilling machine
• Precision tool room machines: lathe, milling machine
• Inspection: height gauge, profile projector
• Universal grinding machine 
• Crane: 2 T Capacity

Space Required

• Workshop of size 12m x 8m x 6m height for manufacturing and fabrication of components
• Dust free room of size 10 m x 8m x 6m height for precision assembly 

Manpower 

8 persons consisting of 2 engineers and 6 technicians for fabrication, assembly and testing of three-piece master-slave manipulator.