Patents by Inventor Tsai-Fa Liu

Tsai-Fa Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8770070
    Abstract: The present invention discloses a universal anti-torque screwdriver head structure integrally formed and divided into a polygonal insert end and a conical action end, and comprising a plurality of pull-push wings disposed around the action end, a stepped recessed formed between two adjacent pull-push wings and extended inwardly from an open end, and the recess having a longitudinal depth slightly greater than an action hole of a screw of a general specification, and the design of the stepped recess provides high-strength torque and tenacity and fits screws of various different specifications.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: July 8, 2014
    Inventor: Tsai-Fa Liu
  • Publication number: 20130276595
    Abstract: The present invention discloses a universal anti-torque screwdriver head structure integrally formed and divided into a polygonal insert end and a conical action end, and comprising a plurality of pull-push wings disposed around the action end, a stepped recessed formed between two adjacent pull-push wings and extended inwardly from an open end, and the recess having a longitudinal depth slightly greater than an action hole of a screw of a general specification, and the design of the stepped recess provides high-strength torque and tenacity and fits screws of various different specifications.
    Type: Application
    Filed: April 23, 2012
    Publication date: October 24, 2013
    Inventor: Tsai-Fa LIU
  • Patent number: 8465234
    Abstract: A drilling bit with the depth-limiting and angle-leading function for the carpenter's work, having a covering sleeve (with a driving shaft) and a bit holder for securing a bit. A limit ring and a screw socket (with female thread) are screwable to the covering sleeve (with the male thread) for adjusting the depth of the spot-faced hole in a workpiece (to be drilled) according to the actual operation requirement.
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: June 18, 2013
    Inventor: Tsai Fa Liu
  • Publication number: 20120000805
    Abstract: A tool holder assembly including a housing with a chamber, a rotating holder with a plurality of slots, torsion spring, and an adapter, thereby forming an easy-to-use and portable tool holder. The slots at the top and the bottom of the rotating holder are provided for receiving screwdriver bits in different shapes and sizes. An insertion hole of the adapter is provided for the insertion of a hand tool in order to tighten a screw. Besides, the rotating holder may be swiveled by means of the torsion spring in an inclined position relative to the housing, thereby facilitating the removal and the storage of the screwdriver bits.
    Type: Application
    Filed: July 5, 2010
    Publication date: January 5, 2012
    Inventor: Tsai-Fa LIU
  • Patent number: 8083060
    Abstract: A tool holder assembly including a housing with a chamber, a rotating holder with a plurality of slots, a torsion spring, and an adapter, thereby forming an easy-to-use and portable tool holder. The slots at the top and the bottom of the rotating holder are provided for receiving screwdriver bits in different shapes and sizes. An insertion hole of the adapter is provided for the insertion of a hand tool in order to tighten a screw. Besides, the rotating holder may be swiveled by means of the torsion spring in an inclined position relative to the housing, thereby facilitating the removal and the storage of the screwdriver bits.
    Type: Grant
    Filed: July 5, 2010
    Date of Patent: December 27, 2011
    Inventor: Tsai-Fa Liu
  • Publication number: 20110110740
    Abstract: A drilling bit with the depth-limiting and angle-leading function for the carpenter's work, having a covering sleeve (with a driving shaft) and a bit holder for securing a bit. A limit ring and a screw socket (with female thread) are screwable to the covering sleeve (with the male thread) for adjusting the depth of the spot-faced hole in a workpiece (to be drilled) according to the actual operation requirement.
    Type: Application
    Filed: November 12, 2009
    Publication date: May 12, 2011
    Inventor: Tsai Fa Liu
  • Patent number: 6530299
    Abstract: The present invention relates to a joint adapter for a power drill screw driver having a driving shaft, a slide socket, a compression spring, a packing ring and a screw driver bit. The driving shaft is provided with an insertion groove and an insertion piece. A neck is located in the middle of the driving shaft. A strong magnet is fixed at the front end of the axial insertion hole. A clamping ring is arranged at a proper place of the axial insertion hole. The compression spring is inserted around the neck of the driving shaft and rests on the clamping ring of the slide socket. The packing ring closely sits at the end of the neck of the driving shaft in a tight state while the compression spring presses against the packing ring so that the compression spring and the slide socket are located in place. A plurality of screw driver bits in a plurality of shapes and sizes each being selectively inserted into the insertion groove of the driving shaft for tightening the screws.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: March 11, 2003
    Inventor: Tsai-Fa Liu
  • Patent number: 5823078
    Abstract: A precision screwdriver having a handle with a rotatable portion consisting of a shaft, a handle, a thrust ring and a rotatable cap. The handle has a cylindrical portion with a raised edge formed on its outer surface, and an internal cavity. The rotatable cap is equipped with a hole therethrough for holding a bearing in the form of a single ball. An internal groove disposed at near the hole serves a securing function when the raised edge of the cylindrical portion of the handle is fitted to the rotatable cap internal groove. A concave securing plate with a hole therethrough is disposed on the outer edge of the rotatable cap hole. The securing plate serves to position the bearing with suitable surface exposed through the securing plate hole. Thus, the rotatable cap can be fitted onto the cylindrical portion of the handle and properly secured by mating the raised edge with the internal groove.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: October 20, 1998
    Inventor: Tsai-Fa Liu
  • Patent number: 5522291
    Abstract: A tool handle having a tool includes a handle having an extended portion with a driving element and a switching button and a recess disposed inside the handle. A tool kit containing various tool parts is accommodated within the recess. An axial rod provided at one end of the recess of the handle and a corresponding hole in the tool kit pivotally connect the tool kit with the recess. The tool kit has a retaining piece for engagement with an engaging edge at the other end of the handle for positioning the tool kit in the recess.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: June 4, 1996
    Inventor: Tsai-Fa Liu
  • Patent number: D416776
    Type: Grant
    Filed: November 6, 1998
    Date of Patent: November 23, 1999
    Inventor: Tsai-Fa Liu