The rotary broaching brake is a new mechanical solution for aligning broached forms in machined products. Rotary broaching is fantastic for making small forms like hexagons and squares in soft materials like aluminum, brass, and mild steel. However, when it comes to aligning multiple holes using a rotary broaching tool, the operation becomes extremely challenging. Most rotary broach holders have a free-turning spindle, which does not allow for alignment of the holes.
Polygon Solutions, Inc. designed the broaching brake to be used as an attachment to its innovative GT Series rotary broach holder. The brake mounts to the tool holder using set screws. Additional screws are included at the opening of the brake to gently tighten against the spindle. The broach is fastened into the spindle, and must make contact and be aligned at the first hole.
When the broach is engaged with the part, the brake is loose enough to allow the spindle to turn without interfering with the broaching operation. Unlike typical rotary broaching operations, turning must stop before removing the broach. When the broach is removed, the brake screws are tight enough to hold the broach’s position until it makes contact with the part at the next hole.
The rotary broaching brake was used recently at the 2012 IMTS show in the Hardinge booth. Hardinge’s innovative Bridgeport® GX 480 APC Vertical Machining Center held multiple broach holders by Polygon Solutions. However, the block was machined with square holes which holes that were aligned to other features on the part. The squares were machined using a broach holder with Polygon’s new rotary broaching brake.
The rotary broaching brake is a lightweight, low-profile tool, and it easily fits into the VMC’s tool changer. It slides onto the head of the holder and does not require special tools for adjustment or assembly. The brake can also be easily removed for operations where it is not required. For more information, go to www.polygonsolutions.com.
