Down-pressed clamp base

A down-pressed clamp base comprising:

• a main body having a space passing through a bottom of the main body and a passage communicating with the space via a connection perforation;
• a transmission member slidable disposed in the connection perforation, two ends of the transmission member being respectively directed to the passage and the space;
• a leverage mechanism including a lever and a link, one end of the lever being a pivoted end pivotally connected with the main body, the other end of the lever being a levering section, the pivoted end of the lever having a pivot point, the lever being rotatable around the pivot point, one end of the link being a pivoted part pivotally connected with the lever, the other end of the link being a free end positioned in the passage and directed to the transmission member, when the levering section of the lever is rotated downward, the link being driven, whereby the free end of the link drives the transmission member to displace toward the space;
• a fastening mechanism disposed in the space, when the transmission member is displaced toward the space, the fastening mechanism being driven;
• and
• a string holding mechanism disposed on the main body, a clamp member being disposed on a top section of the string holding mechanism.