Boschert Safety Chuck Technical Information

Boschert STW 40-50 VT7 - DSB BrakeWith many years of experience in the Converting Industry, Antech Converting and Boschert have teamed up to offer high quality Safety Chucks, Brakes and Clutches to the market in the United Kingdom.

With the invention of the Safety chuck over 60 years ago, Boschert has led the Converting Industry into a new era. Boschert Safety Chucks are, and for the future will be, the standard of the Industry.

Safety Chucks can be supplied to suit many different shaft end configurations with a range suitable for square shaft ends from 14mm to 230mm, in either Pedestal or Flange mounting, to suit individual requirements.

What is a Boschert Safety Chuck?

It is a quick coupling for a shafted center wind and center unwind applications, utilising Air Shafts, Reel Bars & Core Bars.

Safety Chucks do three things:
1. They provide for a quick change at the end of a production run (either winding or unwinding). Therefore, there is less down time during turn around and the more cost effective in operation.
2 . They provide a means of transmitting torque to the roll being wound / unwound. Torque in the form of a drive on the rewind end of the operation and torque from a brake on the unwind side.
3. Finally, Safety Chucks provide for concentricity between centreline, or axis, of the Safety Chuck and the center line of the Air Shaft. Less eccentricity between the Air Shaft and Safety Chuck results in less vibration and wear.

How do you operate a Boschert Safety Chuck?


operate1To load the Safety Chucks for take up or pay off operations, rotate the round locking collar or handwheel to zero degrees. Tilt back the handwheel exposing the square pocket. Lower the shaft square journal into the square pocket of the Safety Chuck.


operate2When the shaft is seated in the Safety Chuck the handwheels are closed by hand prior to start up. If the roll should rotate before the handwheels are closed, the handwheels will automatically start to close at 5 degrees either side of the zero. They will be closed at 15 degrees either side of the zero. This is the safety feature of the Safety Chuck.


operate3Start the operation. Torque is transmitted through the Safety Chuck to the shaft. The speed of the take up and, the amount of tension required can be controlled with the inclusion of a compatible Boschert Brake.  Rotate Chuck to zero position



operate4At the end of the operation rotate the handwheels to zero degrees, tilt the handwheels back and remove the Air Shaft.



What size Boschert Safety Chuck do I have?

The best way to determine the size of the existing Boschert Safety Chuck Dimensions is to measure the diameter of the chrome plated tilting locking collar (handwheel) and to know the the size of the square opening in the Safety Chuck seat (pocket).

Can I retrofit a Boschert Safety Chuck in place of the Safety Chuck brand I currently use?

Yes, you can. All we need to know is:

1. What is the centerline dimension from the bottom of the Safety Chuck to the centre of the Safety Chuck?
2. What is the size of the required square opening in the seat of the Safety Chuck?
3. What is the diameter of the drive shaft?
4. What is the length of the drive shaft from the back of the housing of the Boschert brand Safety Chuck?
5. What is the distance from the rear wall of the square seat to the mounting hole for the Safety Chuck?

For further details of the Boschert Chucks & Ancillary equipment please Click Here