Patents by Inventor Daniel H. Pierce

Daniel H. Pierce 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: 6273045
    Abstract: A valve spring retainer (30) for operatively retaining a return spring (28) on a stem (20) of a poppet valve in an internal combustion engine. The retainer (30) includes a retainer flange (50) extending annularly about and radially from a hole (52) on a central axis A to an outer periphery for engaging the top of a spring (28). A ring (56) is disposed below the flange (50) and extends about the axis A for surrounding the valve stem (20). An inner portion (58) extends cylindrically about the axis A and axially between the ring (56) and the flange (50). A plurality of slots (61) extend radially from the hole (52) to the periphery and divide the flange (50) and the inner portion (58) into sectors (S) leaving the ring (56) to interconnect the sectors (S). The retainer (30) is characterized by the slots (61) being formed to extend radially at a wide width x and with each of the sectors (S) including a limit projection (63) at the periphery to define a narrow width (Y).
    Type: Grant
    Filed: July 26, 1999
    Date of Patent: August 14, 2001
    Inventor: Daniel H. Pierce
  • Patent number: 6273046
    Abstract: The valve stem (20) extends through the ring (56) and the hole (52) in the flange (50) of a retainer (30) and a spring (28) surrounds the stem (20) and engages the flange (50) in the axial direction and a skirt portion (60) in the radial direction. The retainer (30) is characterized by the skirt portion (60) having a waist diameter (W) and first and second annular extending surfaces (62 and 64) respectively extending axially in opposite directions from the waist diameter (W) at an included waist angle of less than 180° relative to one another as the skirt portion (60) is viewed in cross section. The root diameter (R) is larger than the waist diameter (W) and the root diameter (R) is also larger than the distal end diameter (D), but the distal end diameter (D) is larger than the waist diameter (W). The distal end diameter (D) and the ring (56) are radially aligned, i.e., aligned horizontally, and the skirt portion (60) is spaced radially from the ring (56) to define a void or recess (66) therebetween.
    Type: Grant
    Filed: July 26, 1999
    Date of Patent: August 14, 2001
    Inventor: Daniel H. Pierce
  • Patent number: 5255640
    Abstract: A self-locking valve spring retainer (30) operatively retaining a return spring (28) on the stem (20) of a poppet valve (16) comprises an annular base ring (48) from which three flexible arms (52) upwardly extend. A locking step (66) projects radially inwardly from each of the arms (52) to provide an engaging ledge (70) which interlocks with a corresponding mating projection (68) of the valve stem (20). An annular waisted hinge (86) is formed between the three arms (52) and the base ring (48) to ease stresses on the retainer (30) as the arms (52) are blossomed outwardly during installation and removal. The annular base ring (48) is fabricated from a first organic polymeric material capable of deformation thus permitting the arms (52) to flex outward therefrom.
    Type: Grant
    Filed: March 9, 1993
    Date of Patent: October 26, 1993
    Assignee: D.P.I.
    Inventor: Daniel H. Pierce
  • Patent number: 5226229
    Abstract: A self-locking valve spring retainer (30) operatively retaining a return spring (28) on the stem (20) of a poppet valve (16) comprises an annular base ring (48) from which three flexible arms (52) upwardly extend. A pair of axially spaced locking steps (66, 68) project radially inwardly from each of the arms (52) to provide barbed engaging ledges (74, 76) which interlock with a correspondingly shaped valve stem (20). An annular waisted hinge (86) is formed between the three arms (52) and the base ring (48) to ease stresses on the retainer (30) as the arms (52) are blossomed outwardly during installation and removal. A metallic anti-wear plate (88) is secured to the top of each arm (52). An installation and removal tool (92) for the retainer (30) comprises three wedge-shaped prongs (98) insertable within the three expansion slots (54) separating the three arms (52) for blossoming the retainer (30) prior to insertion and removal.
    Type: Grant
    Filed: February 6, 1992
    Date of Patent: July 13, 1993
    Inventor: Daniel H. Pierce
  • Patent number: 5143351
    Abstract: A self-locking valve spring retainer (30) operatively retaining a return spring (28) on the stem (20) of a poppet valve (16) comprises an annular base ring (48) from which three flexible arms (52) upwardly extend. A pair of axially spaced locking steps (66, 68) project radially inwardly from each of the arms (52) to provide barbed engaging ledges (74, 76) which interlock with a correspondingly shaped valve stem (20). An annular waisted hinge (86) is formed between the three arms (52) and the base ring (48) to ease stresses on the retainer (30) as the arms (52) are blossomed outwardly during installation and removal. A metallic anti-wear plate (88) is secured to the top of each arm (52). An installation and removal tool (92) for the retainer (30) comprises three wedge-shaped prongs (98) insertable within the three expansion slots (54) separating the three arms (52) for blossoming the retainer (30) prior to insertion and removal.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: September 1, 1992
    Inventor: Daniel H. Pierce
  • Patent number: 4879978
    Abstract: An engine (10) is provided including a poppet valve (14) for regulating the flow of gases to and from a combustion chamber (13). The poppet valve (14) includes an elongated stem (18). A return spring (20) is connected to the stem (18) and urges the poppet valve (14) perpendicularly toward a valve seat (16). A spring retainer (22) locks onto the stem (18) of the poppet valve (14) to retain the return spring on the poppet valve (14). A central bore (26) is provided in the spring retainer (22) and includes a radially inwardly extending ledge (30). Three equally spaced slots (32) are disposed through the spring retainer (22) for allowing the ledge (30) in the bore (26) to deflect outwardly while the spring retainer (22) is inserted onto the stem (18) of the poppet valve (14).
    Type: Grant
    Filed: August 25, 1988
    Date of Patent: November 14, 1989
    Inventor: Daniel H. Pierce