MUMBAI, India, Jan. 9 -- Intellectual Property India has published a patent application (202511098594 A) filed by Jamna Auto Industries Limited, Yamuna Nagar, Haryana, on Oct. 13, 2025, for 'a stepped collar assembly to prevent bolt failures in heavy commercial vehicle suspension systems.'
Inventor(s) include Sunil Laroiya; Anuj Sharma; Narendra Jat; and Dilip Girdhar Patil.
The application for the patent was published on Jan. 9, under issue no. 02/2026.
According to the abstract released by the Intellectual Property India: "The present invention discloses a stepped collar fastening mechanism for parallelogram-type and trailing arm suspension assemblies in heavy commercial vehicles, designed to prevent torque loss and enhance durability. The mechanism includes a hanger assembly with opposing side plates featuring aligned threaded apertures, a control arm connected via a bushing assembly, and a center bolt extending through the apertures and bushing. A pair of annular stepped collar sleeves, made from hardened materials such as medium carbon steel, EN8, or EN18 grade steel, are positioned on the side plates, with at least one fixed by welding. These sleeves provide enlarged seating surfaces for uniform clamping load distribution, resist embedment and preload decay, and isolate the bolt head, nut, and bushing inner sleeve from painted surfaces to minimize misalignment and assembly gaps. In an alternative embodiment, one sleeve incorporates a sliding component for axial movement during tightening, compensating for clearances and ensuring consistent clamping without torque loss. The design reduces torque loss due to paint compression to less than 20%, improving long-term joint integrity and vehicle performance. Fig. 5: Assembly view with stepped collar sleeves."
Disclaimer: Curated by HT Syndication.
