Barnes Group has been granted a patent for a piston cylinder device that includes a cylinder, a guide, and a pressure chamber. The device is designed with a material weakening zone that can be deformed or sheared upon impact of the piston against the guide, allowing gas from the pressure chamber to escape through a leakage gap. The device aims to prevent fluid leakage and improve the performance of piston cylinder systems. GlobalData’s report on Barnes Group gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Barnes Group, braking system fluid circuit was a key innovation area identified from patents. Barnes Group's grant share as of September 2023 was 58%. Grant share is based on the ratio of number of grants to total number of patents.
Piston cylinder device with a material weakening zone for gas release
A recently granted patent (Publication Number: US11761504B2) describes a piston cylinder device and a method for protecting it against overload. The device includes a cylinder with a wall, an end wall, and an opening, as well as a guide positioned at the second end of the wall. A piston connected to a piston rod is disposed within the pressure chamber formed by the wall, end wall, and guide. The piston rod extends through the guide and into the pressure chamber. A sealing arrangement is positioned between the guide and the inner wall surface of the wall to prevent fluid leakage from the pressure chamber.
The patent introduces a material weakening zone in the inner wall of the cylinder. This zone is located above a locking ring and extends to the second end of the wall or below the second end of the wall, but is spaced from the second end. The material weakening zone is designed to deform or shear in the direction toward the second end of the cylinder when the piston impacts the guide with a predetermined level of force. This deformation or shearing causes the locking ring to push upwardly on a lower portion of the material weakening zone, resulting in the formation of a leakage gap. The leakage gap interrupts the sealing arrangement, allowing gas from the pressure chamber to escape through the gap.
The method for protecting the piston cylinder device against overload involves causing the piston to impact the guide at a predetermined level of force. This impact causes the locking ring to apply a force to the underside of the material weakening zone, leading to its deformation or shearing. As a result, fluid flows into the leakage gap, bypassing the sealing arrangement and reducing pressure in the pressure chamber.
The patent also mentions that the material weakening zone can include a continuous or discontinuous circumferential groove in the inner wall of the cylinder. Additionally, the leakage gap can be partially located between the locking ring and the sealing arrangement, or integrated with a lock ring groove when the material weakening zone is deformed or sheared.
Overall, this patent introduces a piston cylinder device and a method for protecting it against overload by utilizing a material weakening zone and a leakage gap. This innovation aims to prevent damage to the device and reduce pressure in the pressure chamber during high-impact situations.