Toyota Boshoku has been granted a patent for a seat reclining device. The device includes a ratchet, a guide, a pawl, and a rotation cam. The pawl has an eccentric structure that allows it to be pressed and inclined to one side by the rotation cam. It also has protrusions that restrict its inclination and hold it in place. The device is designed to restrict the relative rotation between the ratchet and the guide, providing improved functionality for vehicle seats. GlobalData’s report on Toyota Boshoku gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Toyota Boshoku, Autonomous seating was a key innovation area identified from patents. Toyota Boshoku's grant share as of September 2023 was 40%. Grant share is based on the ratio of number of grants to total number of patents.
Vehicle seat reclining device with eccentric pawl structure
A recently granted patent (Publication Number: US11772527B2) describes a vehicle seat reclining device that includes a ratchet, a guide, a pawl, and a cam. The ratchet and guide are assembled in an axial direction and can rotate relative to each other. The pawl is supported by a pair of guide walls on the guide and can mesh with the ratchet to restrict their relative rotation. The cam is designed to press and move the pawl outward in a radial direction.
The pawl in this device has an eccentric structure, meaning it is pressed and inclined to one side in the rotation direction between the guide walls due to the pressing force from the cam. The pawl also has a first protrusion on the side surface facing the guide wall on the inclined side, which restricts the inclination of the pawl by contacting the guide wall. Additionally, the pawl has a second protrusion on the side surface facing the guide wall on the opposite side, which holds the pawl in a posture where it is in contact with both guide walls. Importantly, the second protrusion is located outward in the radial direction compared to the first protrusion.
The patent also mentions that the pawl can have multiple protrusions, and the first protrusion can extend over the entire area of the main body surface portion of the pawl on the inclined side. Similarly, the second protrusion can have a shape where the slope extends over the entire area of the side surface of the guide wall facing the pawl.
Overall, this patented vehicle seat reclining device offers a unique mechanism for restricting the relative rotation between the ratchet and guide. The eccentric structure of the pawl, along with the first and second protrusions, ensures proper engagement and positioning of the pawl with the guide walls. This innovation may contribute to improved functionality and durability of vehicle seat reclining systems.