How many new invention patents have Zheng Coal Machine had in recent years?

/kloc-above 0/500. Relevant information of Zhengzhou Coal Mining Machinery Group Co., Ltd. shows that the number of new invention patents granted by the company over the years has exceeded 1500. Zhengzhou Coal Mining Machinery Group Co., Ltd. (hereinafter referred to as "Zhengzhou Coal Machine") is located in Zhengzhou, an important transportation hub city in China and the eighth civilized ancient capital. China is a large-scale backbone enterprise specializing in the production of hydraulic supports and one of the top 500 enterprises in the mechanical industry.