Formwork truncation screw rod

Abstract

A formwork truncation screw rod includes a self-tapping screw and at least one fixing part. The self-tapping screw includes a spiral portion around the outside of the self-tapping screw, a driving end, a tapping end at an opposite end of the driving end, a diameter shrinkage portion between the tapping end and the spiral portion, and an extending portion between the tapping end and the diameter shrinkage portion. After the tapping end is fixed to the fixing part, the diameter shrinkage portion is made to protrude from the fixing part. Then, the diameter shrinkage portion is broken to remove the tapping end, thereby preventing the tapping end from damaging to the user. In this invention, the impact to the formworks between which concrete is grouted may be decreased and the formwork support capability may be increased, and few component is needed for quick assembly and simplified process.

What is claimed is: 
     
         1 . A formwork truncation screw rod, being provided for template architecture construction and comprising:
 a self-tapping screw, including a spiral portion formed around the outside of the self-tapping screw, a driving end, a tapping end at an opposite end of the driving end, a diameter shrinkage portion formed between the tapping end and the spiral portion, and an extending portion formed between the tapping end and the diameter shrinkage portion, in which the tapping end is larger than the spiral portion in width diameter; and   at least one fixing part, in which the fixing part is fixedly screwed onto the spiral portion, the fixing part includes a fixedly screwed portion and a leaning portion fixed to one end of the fixedly screwed portion, the fixedly screwed portion includes a screw hole onto which the spiral portion may be fixedly screwed, the screw hole includes at least one groove matching with the tapping end extending, and the leaning portion includes a thru hole communicating with the screw hole, in which after the tapping end is connected and fixed to the fixing part, the diameter shrinkage portion is made to protrude out of the fixing part and thereby the diameter shrinkage portion is broken to remove the tapping end.   
     
     
         2 . The formwork truncation screw rod according to  claim 1 , wherein the tapping end includes a cutting portion formed at a side of the tapping end and a chip discharging portion formed near a side of the cutting portion. 
     
     
         3 . The formwork truncation screw rod according to  claim 2 , wherein the chip discharging portion has a chip discharging space. 
     
     
         4 . The formwork truncation screw rod according to  claim 1 , wherein the driving end is a polygonal pillar that is triangular, quadrilateral, pentagonal, hexagonal, heptangular, octagonal, enneahedral, or decagonal. 
     
     
         5 . The formwork truncation screw rod according to  claim 1 , wherein the leaning portion is non-plane and has a friction end far from a side of the fixedly screwed portion. 
     
     
         6 . The formwork truncation screw rod according to  claim 1 , wherein the friction end is formed into at least one hemispheroid, or at least one spheroid, or at least one groove, or at least one rib, or at least one polygonal pyramid, or at least one conoid, or at least one saw tooth. 
     
     
         7 . The formwork truncation screw rod according to  claim 1 , wherein the formwork truncation screw rod includes a sleeve and the sleeve includes a connection portion sleeved around the driving end, and a driven portion formed at an opposite side of the connection portion.