Rivet/Spot Welding


Series 17 Checkmate Riveter Guard

The Series 17 Checkmate is the latest state of the art, point of operation guarding device that provides economical, reliable protection for operators of riveters, spot welders, clinchers and small staking presses. The Checkmate is available in models for use on full or part revolution riveters using either air or electric power. The unit interfaces with existing electric or pneumatic machine controls, and is available in either right or left hand configurations for easy placement and installation. The Checkmate can also be integrated into foot treadle machines using the optional actuator conversion kit.

Checkmate’s Light weight aluminum wand closes the point of operation with a downward motion on actuation of the operator’s  trip control. Should the gravity-completed fall of the wand be interrupted at any point short of full travel, the Checkmate’s circuitry will remain “open” and fail to make the logic necessary for completion of the tripping signal. Removal of the interruption and reactivation will permit completion of the “single shot” tripping signal circuit and allow subsequent stroking of the machine. If the optional “contact” feature is selected “on”, the wand must additionally make metal-to-metal contact with the part in order to initiate the single shot circuitry. If contact with the part is not made the tripping logic is not completed. The action of the wand is extremely rapid and does not adversely impede production. The actual time required for the Checkmate to do its job is less than a second, and the wand returns to its “up” position after release of the operator station just as quickly. The unit is easily adjusted to accommodate any fixture, tooling, or changes in the profile of the workpieces.

The Checkmate is easily installed on most machines. The rugged, all extruded aluminum enclosure mounts with just two bolts to either a customer-provided fabricated mounting or the optional “universal” mounting bracket. Once mounted, the unit may be adjusted for “side to side” or “bottom” of wand stroke by means of a single allen tool.  Further adjustment of the wand may be made by forming the wand to fit a special application. The standard adjustable wand is designed for quick and simple allen/hex wrench adjustment when requiring set up changes. The optional “universal” mounting bracket provides greater adjustment capability through vertical height and axial/swivel placement of the Checkmate enclosure and wand assembly.

Interfacing the Checkmate with the machine controls is simple. The electric Checkmate requires a 110-120 VAC power source and two-wire interconnection with the machine’s 110-120 VAC controls which, in turn, will interface with the electric hand or foot controls. The pneumatic Checkmate requires the same power source and interfaces with any pneumatic hand or foot control. Pneumatic units are supplied with a pressure sensor and solenoid valve for this interface. All units require an air supply source.

All standard Checkmates feature a maximum protection stroke of 4”. This stroke is infinitely adjustable down to one inch, requiring only one allen tool and taking just a few seconds to adjust.

Should the machine to be fitted with Checkmate protection have a purely mechanical tripping system, PROTECH can provide an actuation conversion kit for fast, reliable and safe activation of the clutch control. The conversion can be for either air or electrical operation for best-suited application.

  • Anti-doubletrip circuitry; successive stroking of machine requires intentional multiple operator actuation of the tripping control.
  • Anti-tiedown circuitry prevents wand from being tied down in closed position; wand must complete its intended cycle every time.
  • Optional metal-to-metal wand “contact” tripping logic with supervisor “off-on” key, selectable by user at time of setup.
  • Self-checking circuitry assures reliable operation on every stroke. A Checkmate internal malfunction will preclude machine operation until corrected.
  • 10 Amp rated 110-120 VAC output for high reliability and long life with “single shot” solid state output logic.
  • Internally fused circuit protection.
  • Wand stroke is infinitely adjustable to a maximum of 4”. Adjustment of wand takes only a few seconds.
  • Electric models interface directly with any 110-120 VAC machine control and can be adapted to others.
  • Pneumatic models interface with any air foot or hand control and are supplied with operator station air pressure sensor and air solenoid valve. (Requires 110-120 VAC power for installation)
  • Simple two-bolt mounting to machine or optional “universal” mounting brackets.
Model Description
17-61 Electric, Contact Output Right Hand mount
17-62 Electric, Contact Output Left Hand mount
17-71 Pneumatic, Valve Output Right Hand mount
17-72 Pneumatic, Valve Output Left Hand mount

Metal-to-metal “contact” logic with supervisory key “off-on” switch add “M” suffix to CHECKMATE Model Number when selected.

87 PCKE Electric foot switch actuator conversion kit for mechanically tripped machines; includes 1×1” air cylinder, 1/4” air supply filter, regulator with gauge, lubricator, solenoid valve and guarded electric foot switch. (Used with 17-61 or 17-62 units)

87 PCKP Air foot control actuator conversion kit for mechanically tripped machines; includes 1×1” air cylinder with quick exhaust, 1/4” air filter, regulator with gauge, lubricator, and guarded air foot control. (Used with 17-71 and 17-72 units)

“Universal” Z mounting bracket and clamp assembly.
Kit 18-86


Unitrol Soft Touch

The World’s First Passive Pinch Point Safety System

Designed to prevent Spot Welders, Riveters, or other machines from applying full force at the pinch point if it detects fingers 

Soft touch technology will make your equipment pinch-proof without loosing a minute of productivity.

NEW Features:

Easier Setup:
No User Calibration, EVER. Just install and turn power ON.

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 re-calibrate. 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.

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.


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.

Please watch the video below to know more about the benefits and savings the Soft Touch will do for you!

Installation on your equipment is critical, we have an experienced team of technicians and installers that can install your Soft Touch system and train your operators on its safe use.

Choosing the right Soft-Touch  Safety System for your Spot Welder



These options protect against pinch point injury when bringing the electrodes out of RETRACT and to the WORK POSITION. While spacing between electrodes in the WORK POSITION is typically ½”, the spacing is adjusted by the operator or setup person and can be very small if not done correctly. Since a normal RETRACT system closes electrodes using full line air pressure, any body part caught between the electrodes will be severely injured.The SOFT TOUCH RETRACT options bring the electrodes down to the WORK POSITION (small opening between electrodes) with low force. This low force remains until the first weld is started and continuity between the electrodes is detected. At that time the full RETRACT force is turned on and remains until RETRACT is released. It is offered in two models:

9181-34JA: For use in RETRACT systems that have a 3-level foot switch to both turn on and latch the RETRACT and also then start the weld. This option includes a proximity switch and bracket to be installed on the welder. The proximity switch should be adjusted to close when the system is in the lowered WORK POSITION.

9181-34JB: For use in RETRACT systems that have a separate foot switch to turn on the RETRACT function. A proximity switch is not required and is not supplied with this option.


9181-34BPA: This option is used when welding material that has high-resistance coatings such as titanium oxide. It is also useful when parts have heavy non-conducting coatings, such as drawing compounds, which will prevent continuity between the electrodes. The option includes a faceplate with a high-security key switch and two LED indicators. The switch can be set for CONTINUITY or TIMED DELAY.LIMIT SWITCH

9181-34LSA: This option is used when redundant systems are required. The option includes a proximity switch with bracket to be mechanically set to close when the electrodes are less than ¼” apart. The SOFT TOUCH system will not bring the electrodes to full welding force until both this proximity switch is closed and continuity is detected.

9181-34LSB: This option provides a selector plate with a high-security key switch and two LED indicators. It is used to allow welding of material that has poor conductivity or has poor-conducting coatings. The proximity switch acts as a depth switch. It is set to close when the electrodes are less than ¼” apart. The switch allows selection between continuity and depth switch as needed when welding various materials. 115V VOLTAGE SOURCES:

9181-34TECNA: This option is for use with TGECNA welding controls. It includes a 115VAC transformer and two line fuses factory wired into the main control cable. Input can be 230VAC or 460-VAC. The output of the SOFT TOUCH system is changed from Normally Open to Normally Closed to match the TECNA second-stage initiation scheme. 9181-34/115: This option is used for welding controls that do not have a 115VAC source. It includes a 115VAC transformer with two line fuses factory wired to the main control cable. Input can be 230VAC or 460VAC.

9181-34AM-ID40ST: This option is required when installing SOFT TOUCH on a welder that has an Amada/Miyachi ID40ST welding control. It includes a relay system to handle the unique initiation sequence of that control.

9181-34AM-ID40IVST: This option is required when installing SOFT TOUCH on a welder that has an Amada/Miyachi ID40IVST welding control. It includes a relay system to handle the unique initiation sequence of that control.