Three blind bolts from one pulling head

Citation

(2005), "Three blind bolts from one pulling head", Aircraft Engineering and Aerospace Technology, Vol. 77 No. 1. https://doi.org/10.1108/aeat.2005.12777aad.009

Three blind bolts from one pulling head

Three blind bolts from one pulling head

Keywords: Aerospace industry, Aircraft components, Assembly

Textron Fastening Systems, a business unit of Textron Inc. recently introduced a blind fastening process that is reported to allow three different size bolts to be installed with one pulling head in the assembly of high-strength aerospace structures.

The MaxiBolt Plus blind bolt produces a large diameter footprint that distributes the bearing load of the joint over a wide area of the blind side of composite and metallic work pieces. This disperses stress on the joint, providing an operational grip range that prevents stripping, tearing, or delaminating composite material, while reducing the need for additional fasteners.

“The MaxiBolt Plus blind bolt system is quick, consistent, cost-effective, and responsive to the aerospace industry's need for automated processes involving composite and metallic materials in critical structural assemblies”, said Martin Schnurr, Executive Vice President of Sales and Marketing for Textron Fastening Systems. “Using this process will enable manufacturers and service centers to increase productivity by eliminating slowdowns to replace nosepieces for different size bolts”.

The first application for the MaxiBolt Plus blind bolt, Schnurr said, is assembly of the wing flap to the wing box on the new Airbus A380 800- passenger commercial jet, scheduled for introduction in 2007. Other targeted applications include floor and ramp assemblies, empenage assemblies, engine inlets, and other critical structures where the opposite side of the material is inaccessible.

MaxiBolt Plus blind bolts are available in multiple head styles in stainless steel and titanium sizes 5, 6 and 8 (5/32 in., 3/16 in., 1/4 in.).

According to Textron they install in 2 s, using a standard Textron Fastening Systems hand tool, or by automated and robotic processes. A common groove on the pulling serration allows each bolt to be interchanged with a common pulling head.

The bolts lock positively and break flush to the material, with no deburring said to be required. Each bolt has a 78 backside slope capability.

Textron Fastening Systems, has also introduced an aircraft interior assembly process that it claims can reduce installation times by 3 min in aluminum structures.

Called Cherry Rivetless Nut Plate, the new fastener has a retainer that expands during installation through a single drill- quality hole, and does not require flaring to meet NASM25027 torque out and push out requirements. In contrast to standard riveted nut plates, it does not require two additional rivet holes or reaming, counterboring and countersinking procedures.

“Cherry Rivetless Nut Plate was introduced for use in assembly of aircraft exterior structures, and now we have brought it inside the cabin”, said Martin Schnurr, Executive Vice President of Sales and Marketing for Textron Fastening Systems.

Interior applications Schnurr cited for Cherry Rivetless Nut Plate include luggage and storage bins, seat tracks, cargo floor platforms, avionics mounting racks, galleys and cockpits, electrical and plumbing connections, and doors, hatches and windows.

“The system works effectively wherever attachments are joined to aluminum structures, helping reduce assembly costs and removing weight from the aircraft”, Schnurr said.

Cherry Rivetless Nut Plate applies in less than 2 s in aluminum sheets as thin as 0.062 in., using standard Textron Fastening Systems assembly tools. Expansion of the retainer sleeve during installation enhances fatigue life of the parent material, and its extended grip range helps reduce part numbers and inventory.

For further details contact: Textron Fastening Systems. Tel: +1.800 544 6117 (US & Canada), +1 815.  961.5300 (international); E-mail: info@tfs.textron.com; Web site: www.textronfasteningsystems.com