UNITROL SOFT TOUCH Pinch Point Safety System

1. Fail Safe Operation:

• If any of the system sensor wires become shortened or disconnected, the SOFT TOUCH system will lock out and not let the electrodes close or the welding sequence to continue.
• If the SOFT TOUCH sensor board detects electrode continuity before the foot switch or hand switches are closed, the system will lock out and not allow any electrode movement.

2. No Operator Adjustments:

• Workers cannot remove, circumvent or tamper with any part of the system.
• No operator set components.
• Does not require any adjustments when new setups are made.
• No user calibration. Just install and turn power ON.

3. No Operator Bypassing:

• The continuity system cannot be overridden and is in place at all times that the welding machine is under power.

4. Primary System:

• Can be used as the primary pinch-point safety system because it is fully passive.

5. Full-Electrical Redundancy:

• All inputs and outputs require closure of both electro-mechanical and solid-state redundant components for fail safe operation. Self-monitors output relay to prevent any operation if a fault in the output contacts is detected.
• When welding a C-shaped part that is not fully closed and requires electrode force to push the parts together, a limit switch can be added to the welder, and be adjusted to close when the space between the electrodes is less an ¼’. In this case, two actions are required before the electrode force increases and the rivet or weld sequence starts.

6. Does Not Stop Production:

• Automatically compensates for changes in transformer tap switch position or line voltage shifts.

7. Works with All Types of Welders:

• SOFT TOUCH systems are available for all resistance welders, including spot welders, projection welders, seam welders and transgun welders; 1Ø AC, 1Ø DC secondary, 3Ø frequency converters, 3Ø DC rectified secondary, and MFDC (inverters).
• Other Machine Types: Pneumatic riveters, pneumatic clinching machines, eyeletters, stakers, crimpers, fastening and assembly machines.

• Easier Setup: No User Calibration, EVER. Just install and turn power ON.
• Universal: Works with Non-Unitrol MFDC inverter and 1 Phase AC controls. Change two plug-in relays for use with 115VAC or 24VDC solenoid valve voltage.
• Always ready to protect: Does not have to be calibrated even when you power-up, change material or change tooling.
• Instantly tunes to your welder: Does not stop production to recalibrate. Automatically compensates for changes in transformer tap switch position or line voltage shifts.
• New look: Easy-to-Read Operation Display. Shows exactly what is happening. Can be mounted on either side of enclosure.
• Supports SOFT TOUCH RETRACT: Just add optional RETRACT pneumatic system with HEAD DOWN limit switch for full protection.
• Full electrical redundancy: All inputs and outputs require closure of both electro-mechanical and solid-state redundant components for full safe operation. Self-monitors output relay to prevent any operation if a fault is detected.

As Always, The UNITROL SOFT TOUCH:

• Cannot Be Bypassed
• Sensor Wires Always Clear of Production Area: Sensor wires are connected at output of welder secondary. Never needs sensor wire location to be moved closer to the electrodes for any type of welder.
• Fast Release: Electrodes close under low force and release in less than half of a second if metal is not detected between electrodes.
• Electrodes Close Without Initial Delay: Electrodes start to move at the same time the welding control is initiated. Closing speed is independent of welding pressure.
• Works with Ram Depth Limit Switch: For redundant system requiring both Electrode Continuity and Ram Depth Limit Switch closure.

SOFT TOUCH replaces the existing solenoid valves and is supplied in a single NEMA-4 enclosure that is factory pre-wired and pre-plumbed.

SOFT TOUCH can be used with all types of metals on press welders, rocker arm welders, portable gun welders, and hanging gun welders doing spot, projection and seam welding.

What hardware is needed: To make this system operate, you will have to add a 5-way externally piloted solenoid valve, a shuttle valve, and a precision pressure regulator system to an existing 4-way externally piloted (or direct acting) solenoid valve. UNITROL offers three kits for easy installation:

Heavyweight Rams: Kit #9181-34W is used on:

• Press welders that have dead weight (with air disconnected from welder) of over 50 pounds. The kit is factory pre-plumbed for fast installation and includes all necessary components and interconnecting tubing.

Lightweight Rams: Kit #9181-34Y is used on:

• Press welders – that have dead weight (with air disconnected from welder) that is less than 50 pounds, or does not drop by its own weight.
• Rocker arm welders – the kit is factory pre-plumbed for fast installation and includes all necessary components and interconnecting tubing.

Lightweight Gravity Drop Rams: The #9181-34H kit is used on:

• Press Welders that have dead weight (with air disconnected from welder) of less than 50 pounds and drops smoothly by gravity. The kit is factory pre-plumbed for fast installation and includes all necessary components and interconnecting tubing.

Redundant sensor: You can also add your own proximity switch or LVD system adjusted to close a switch when the electrodes are less than ¼” apart to the system. The SOLUTION will not turn on the high-pressure valve until both METAL is detected and the proximity switch has been closed. This is often useful for applications where the parts being welded are not flat prior to the weld.

Compliance: Developed in combination with OSHA and guaranteed to be in compliance.

• OSHA 1910.212(a) – General Machinery
• OSHA 1910.255(b)(4) – Resistance Welding Machines
• OSHA 1910.217(c)(3)(iii) – Presence Sensing Point of Operation Device
• ANSI B11.19-2010 (8.7) (Safeguarding Methods Standard)
• ANSI B154.1-1995 (Rivet Setting Equipment)

Warranty: SOFT TOUCH is covered under a limited 5-year prorated warranty. Please refer to the product manual for more information on the warranty.