US Patent 7984768 Spring tensioned scraper for disc opener

A ground opener unit for a seeding or planting unit includes an accessory mount attachable to an implement frame and a disc rotatably mounted to the accessory mount for forming a furrow in the ground. A scraper assembly includes a scraper plate defining a scraper edge for contacting and scraping a surface of the disc. The scraper plate is mounted to the arm by a pivot pin whose length defines a pivot axis about which the scraper plate may pivot in response to deflection of the disc. A spring is generally held in compression to bias the scraper plate against the disc.