Toggle-locking tool

A method for securely holding an object under high pressure in the jaws of a toggle-locking tool that comprises conventional toggle-locking tool parts including a fixed handle, an upper jaw, a lower jaw, a moveable handle, and a lever arm having a bearing end slidable in a channel of said fixed handle, said parts being joined conventionally by toggle linkages, and that in addition comprises an adjustment screw assembly comprising an adjustment screw, adapted to be fed into and to engage a threaded bore in the outer end of the fixed handle of a said tool, having an internal bore extending through its length and including a fine-threaded portion, and a force-enhancing shank comprising a head portion, a fine-threaded intermediary portion, and an end portion, said shank being adapted to be fed into and threaded within the internal bore of said adjustment screw to a position wherein said end portion of said shank extends beyond said adjustment screw to contact said bearing end of said lever arm directly or through a bearing block, said method comprising the steps of:

• (a) adjusting said adjustment screw to a position whereby a said object may be grasped within the jaws of the tool by closing the moveable handle towards the fixed handle;
• (b) grasping said object within the jaws of the tool by closing the moveable handle towards the fixed handle with sufficient force to cause the actuation of said toggle linkages and thereby lock said object within said jaws;
• and
• (c) rotating the head portion of said shank to thread said shank more deeply within said adjustment screw and thereby enhancing the holding force applied by said jaws to said object.

A tool comprising toggle-locking tool parts including a fixed handle having an outer end comprising a threaded bore adapted to receive an adjustment screw and also having a channel for slidably receiving a bearing end of a lever arm, an upper jaw member integral with the opposite end of said fixed handle, a lower jaw member, a movable handle, and a lever arm having a bearing end, said parts being conventionally arranged with appropriate toggle linkages to form a toggle-locking tool, the improvement consisting of an adjustment screw assembly comprising,

• (a) an adjustment screw, adapted to be fed into and to engage said threaded bore in the outer end of said fixed handle, said adjustment screw itself comprising an internal bore extending through its length and including a fine-threaded portion;
• (b) a first force-enhancing shank comprising a head portion, a fine-threaded intermediary portion, and an end portion, said shank being adapted to be fed into and threaded within the internal bore of said adjustment screw to a position wherein said end portion of said shank extends beyond said adjustment screw, said first force-enhancing shank itself comprising an internal bore extending through its length and including a threaded portion more finely threaded than the internal bore of said adjustment screw;
• and
• (c) a second force-enhancing shank comprising a head portion, a threaded intermediary portion, and an end portion, said shank being adapted to be fed into and threaded within the internal bore of said first force-enhancing shank to a position wherein said end portion of said second force-enhancing shank extends beyond said adjustment screw.