Apparatus for forming a slot in a headless screw

{
  "publication_number": "US5833543A",
  "country": "US",
  "kind": "A",
  "title": "Apparatus for forming a slot in a headless screw",
  "abstract": "An apparatus for forming slots in headless screws includes a rotatable disc holding, along its circumferential end, a plurality of clamps which extend radially and are spaced apart circumferentially and which respectively have radial screw receiving spaces opening at the circumferential end, a feeding member provided above the rotatable disc to drop screws into the screw receiving spaces successively, a rotary cutter unit provided downstream of the feeding member for successively cutting the ends of the screws exposed from the screw receiving spaces, and a press member provided adjacent to the rotary cutter unit for successively pressing the clamps to their clamping positions. Each clamp has first and second components which include connecting parts interconnected to one another and clamping parts having cavities that complement one another to form the screw receiving space. The clamping part of the second component is bendable towards the clamping part of the first component when pressed by the press member.",
  "claims": [
    "1. An apparatus for forming slots in headless screws comprising: a rotatable disc having a horizontal shaft and a circumferential end; a plurality of clamps which are mounted on the rotatable disc and which extend radially and are spaced apart circumferentially along said circumferential end, each of said clamps including a first component and a second component having clamping parts adjacent to said circumferential end and connecting parts inwardly of said clamping parts, said clamping parts being normally spaced apart from each other and said connecting parts being connected to one another, said first and second components being aligned in an axial direction of said rotatable disc and provided with cavities in said clamping parts for complementing one another to form a screw receiving space which is open substantially at said circumferential end for exposing one end of said headless screw, said second component having a resiliently bendable part between said clamping part and said connecting part thereof for permitting said clamping part of said second component to bend toward said first component, each of said cavities having a segment-shaped cross-section and an arched clamp face for contacting said headless screw when said clamping part of said second component moves toward said first component to be in a clamping position; a feeding member provided above said circumferential end for dropping said headless screws into said screw receiving spaces one after the other; a rotary cutter unit rotatable about an axis parallel to said shaft of said rotatable disc and provided adjacent to said circumferential end, said rotary cutter being located downstream of said feeding member so as to cut successively the ends of said headless screws which are exposed from said screw receiving spaces of said clamps, respectively; and a press member provided adjacent to said rotary cutter unit for pressing said clamping part of said second component of each of said clamps to the clamping position to grip said headless screw which is being cut by said rotary cutter unit.",
    "2. An apparatus as claimed in claim 1, wherein said second component of each of said clamps is recessed to reduce the thickness thereof in said resiliently bendable part to provide resiliency.",
    "3. An apparatus as claimed in claim 1, wherein said press member is axially spaced apart from the plane of said clamping part of said first component of each of said clamps pressed thereby, so as to confine a clamping space with said clamping part of said first component, said clamping part of said second component being bent towards said clamping part of said first component when received in said clamping space.",
    "4. An apparatus as claimed in claim 3, wherein said press member includes a flat press face to confine said clamping space and an inclined face upstream of said flat press face relative to the forward direction of said rotatable disc, said inclined face providing a guide passage which tapers toward said clamping space for guiding access of said clamping parts of said second components of said clamps into said clamping space.",
    "5. An apparatus as claimed in claim 1, wherein said first and second components have outer ends where said screw receiving space is open, said clamping part of said second component being shorter than said clamping part of said first component so that said outer end of said second component terminates inwardly of said outer end of said first component.",
    "6. An apparatus as claimed in claim 1, wherein said first and second components in each of said clamps are formed as separate pieces.",
    "7. An apparatus as claimed in claim 6, wherein each of said clamps further has a U-shaped holding plate to hold together said connecting parts of said first and second components of each of said clamps, said U-shaped holding plate having two arm portions sandwiching said connecting parts, one of said arm portions and said connecting part of said first component being fastened to said rotatable disc, the other one of said arm portions and said connecting part of said second component being fastened together.",
    "8. An apparatus as claimed in claim 1, wherein said first and second components of each of said clamps are formed into one piece.",
    "9. An apparatus as claimed in claim 1, wherein said rotary cutter unit includes a pair of rotary cutters which rotate in opposite directions, one of said rotary cutters being provided downstream of the other one of said rotary cutters, said one rotary cutter being rotatable to commence cutting from an upstream side of said slot of each of the headless screws and to terminate cutting midway of said slot, said other rotary cutter being rotatable to commence cutting from a downstream side of said slot of each of the headless screws and to terminate cutting midway of said slot to complete formation of said slot."
  ],
  "description_excerpt": "1. Field of the Invention This invention relates to an apparatus for making a headless screw, more particularly, to an apparatus for forming a slot in a headless screw to engage a tool such as a screw driver. 2. Brief Description of the Prior art As shown in FIG. 1, headless screws are fabricated conventionally by first cutting blanks 82 from an elongated rod 80 and then forming a slot 84 in each blank, followed by formation of a screw thread 86 on the slotted blank. A problem encountered with this fabrication method is that the slot 84 tends to deform in a manner as shown by the dotted line due to the pressure induced by the thread forming apparatus during formation of the screw thread 86, thus failing to achieve the predetermined dimension. To alleviate the problem of the above-mentioned fabricating method, some manufacturers have developed a method in which slots are formed in screws after formation of the screw threads. Specifically, as shown in FIG. 2, this method comprises the step of forming a screw thread on an elongated blank 90 which is held in place by a clamp 92 having upper and lower clamp parts 920 and 922. The threaded elongated rod is cut into headless screws having a predetermined length with a cutter 94, and a slot 900 is formed at the end of the threaded elongated rod before each cutting operation of the elongated rod. As such, a predetermined amount of headless screws with slots can be formed from a blank. Although this method has solved the problem of slot deformation, it suffers from the following drawbacks:",
  "cpc": [
    "B23G 9/002",
    "B23Q 7/02",
    "B25B 5/06",
    "Y10S 470/904"
  ],
  "ipc": [
    "B23Q 7/02",
    "B25B 5/06"
  ],
  "assignees": [
    "MING LIAU CO LTD"
  ],
  "inventors": [
    "YANG WEN-REUY"
  ],
  "filing_date": "1997-03-18",
  "publication_date": "1998-11-10",
  "grant_date": "1998-11-10",
  "priority_date": "1997-03-18",
  "application_number": "US-82077897-A",
  "family_id": "25231703",
  "citations": [
    "GB2056890A",
    "US2746065A",
    "US2980928A",
    "US3222702A",
    "US3760443A",
    "US4030153A"
  ]
}