Standard threaded torque fastener with novel indentation patterns to enhance torque and self-locking capabilities

• Main Authors: Majumdar, Barun, Bhattacharya, Arunabh
• Format: Patent
• Language: English
• Published: 02.05.2006

The novel concept to be patented involves minutely indenting the standard fasteners along the pitch line at various points and utilizing the small material deformations around these indentations to provide substantial engagement to resist loosening of the joint under operational loads. The basic idea is to stamp a typical pattern (two are described below) on the fastener to achieve the advantages of a self-locking mechanism as well as enhance the torque and load carrying capability of the joint. Moreover, the indentations being in the order of few mils would not degrade the strength of the fastener, but would continue to provide sufficient load transfer across the joint without loss of preload. Furthermore, the joint can be disassembled and the fasteners can then be reused for the subsequent operations. These unique indentations on the fasteners can be of varying numbers, depths, geometry (spherical, elliptical etc.) and of various patterns (linear, staggered etc.) as dictated by the requirements of an application. The fastener can then withstand a considerable high temperature stress depending on its material composition/alloy. Lastly, the fastener can also withstand moderate to intense vibration depending on the added torque value by decreasing or increasing the number of indentations. In summary, the uniqueness of our concept lies in utilizing these indentation patterns in a simpler inexpensive way to achieve self-locking capability and meet the life cycle requirements of the joint for any given engineering application.