Bertsch Bending Roll Retrofits

Bending Roll


Many of our earlier mechanical plate bending machines are equipped with the slip ring type motor to provide plate feeding power, and this was controlled by a manual reversing drum controller operating in conjunction with grid resistors to the secondary circuit of the slip ring motor.

Solving Historic Issues

This drum controller was always an expensive item to maintain, and it has now also become expensive to replace. Recent federal, state, local electrical and OSHA codes usually require reduced voltage control circuits, which were not possible with the earlier style drum controller, which used full line voltage for operation.

In view of the above, we have developed and can furnish a “tri-speed” electrical control package for any of our Bertsch machines equipped with the manual drum controller. This controller will eliminate the full voltage manual drum controller and has been designed to replace the electrical control items for the earlier machines.

In the “tri-speed” control package, all controls are rewired and mounted in a single NEMA-12 enclosure. This NEMA-12 cabinet is bolted to a platform designed to mount on the front side of your machine at the drive end. The platform also provides adequate guarded space below in NEMA-12 cabinet to mount the necessary grid resistors.

Simplified Console

The package also includes a simplified operator’s control console, conveniently attached to the NEMA-12 cabinet. The console incorporates a rugged spring-centered safety “joystick” operating at reduced voltage for controlling the “forward-neutral-reverse” roll feeding action. For maximum safety to the machine operator, the plate feeding action is a two-handed operation, which requires both hands on the control desk during rotation of the roll forgings.

The “tri-speed” control package utilizes the existing wound rotor, main drive motor and grid resistors. If the present main drive motor is not equipped with a brake, then the correct size brake must be added for the complete machine to meet current safety standards.

Assistance Available

If a brake cannot be added to your present main drive, wound rotor motor, then it will be necessary for you to purchase a new main drive motor complete with the proper brake. We can assist with equipping the machine with the necessary brake on the main drive, wound rotor motor. Please contact us at 800-338-5471 for further information if you need assistance with this.

For any machine to pass current safety requirements, it is also necessary to install around the entire nip point area some type of device to allow anyone in this area to stop the machine quickly. In view of this, we also offer a safety or emergency “stop” kit.

The complete specifications for the “retrofit” electrical package and the emergency “stop” kit are as follows:

Multi-motor control cabinet including all the following control items mounted and wired to terminal strips:

  • Manual, fused disconnect with lock-feature
  • 110-volt control transformer and separately fused and grounded control circuit
  • Reversing starter for the main drive plate feeding motor with thermal protection
  • Two additional contractors providing the second and third speed points of the main drive motor-grid resistor speed control system
  • Main drive motor brake control circuit
  • Reversing starter for the rear roll adjusting motor with thermal overload protection
  • Two reversing starters, each with thermal overload protection for the two motors used for adjusting the lower front pinch roll (This item is optional, and not included when machine has manual adjustment for the lower front pinch roll.)

Operator’s control station, rigidly attached to the above control panel with the following items mounted and wired for operation:

  • Combination push-to-stop, pull-to-start mushroom switch
  • Special spring return to stop joystick switch for the main drive plate feeding system, with three speed points “forward” and three speed points “reverse”
  • Vertically mounted safety mushroom switch which must be depressed (simultaneously with the operation of the main drive), thus requiring two-hand operation to run the main drive motor
  • Spring return to stop joystick switch for “up-down” control of the rear roll
  • Optional (two) spring return to stop joystick switches for “up-down” control of the lower front roll power wedge motors
  • Duplicate copies of electrical wiring diagrams and electrical replacement parts number

The emergency “safety” kit includes:

  • Two (front and rear) emergency “stop” switches, guides, and cable
  • Duplicate safety warning plates of durable metal

Contact us today at 800-338-5471 for the assistance you need to retrofit your Bertsch bending roll.