{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "ratchet-feed-lever-mechanism",
 "name": "Ratchet wheel stepped by a swinging pawl lever",
 "kind": "hardware",
 "category": "Mechanisms",
 "group": "Intermittent motion",
 "year": null,
 "question": "How does a pawl lever step a ratchet wheel?",
 "tags": [
  "mechanism",
  "intermittent motion",
  "kinematics",
  "507 mechanical movements"
 ],
 "aliases": [
  "ratchet feed",
  "ratchet lever",
  "intermittent ratchet",
  "pawl and ratchet mechanism",
  "trinquete con palanca de avance",
  "Schaltwerk mit Klinkenhebel"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/ratchet-feed-lever-mechanism/",
 "sheet_txt": "https://xemstudio.com/objects/ratchet-feed-lever-mechanism/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown No. 225 (1868)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A lever swinging on the wheel's shaft carries a pawl: on the working stroke the pawl pushes a tooth's steep face and turns the wheel; on the return it rides back over the sloping backs. Rocking becomes step-by-step rotation, one or more teeth (15° each for 24 teeth) per stroke.",
   "Catalog 24-tooth Ø40 ratchet wheel with a feed pawl on a 30 mm arm; drawn at the start of a working stroke with the pawl's end face flat on the tooth's steep face (contact only).",
   "Brown's No. 225 (pawl on a vibrating arm turning a ratchet wheel intermittently). A light spring keeps the pawl down (not drawn).",
   "Parts (each has its own page): ratchet-wheels, ratchet-feed-pawl-24t-d40, ratchet-feed-arm-30, dowel-pins-metric.",
   "Brown's movement No. 225 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "wheel",
     "24 T, Ø40 (catalog)"
    ],
    [
     "step",
     "15° per tooth"
    ],
    [
     "pawl pivot radius",
     "30 mm"
    ]
   ]
  }
 },
 "sheet_text": "Ratchet wheel stepped by a swinging pawl lever — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/ratchet-feed-lever-mechanism/  (CC BY 4.0)\nBasis: Xem Studio design following Brown No. 225 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A lever swinging on the wheel's shaft carries a pawl: on the working stroke the pawl pushes a tooth's steep face and turns the wheel; on the return it rides back over the sloping backs. Rocking becomes step-by-step rotation, one or more teeth (15° each for 24 teeth) per stroke.\n- Catalog 24-tooth Ø40 ratchet wheel with a feed pawl on a 30 mm arm; drawn at the start of a working stroke with the pawl's end face flat on the tooth's steep face (contact only).\n- Brown's No. 225 (pawl on a vibrating arm turning a ratchet wheel intermittently). A light spring keeps the pawl down (not drawn).\n- Parts (each has its own page): ratchet-wheels, ratchet-feed-pawl-24t-d40, ratchet-feed-arm-30, dowel-pins-metric.\n- Brown's movement No. 225 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter  value\nwheel  24 T, Ø40 (catalog)\nstep  15° per tooth\npawl pivot radius  30 mm\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala\n- 507movements.com: Brown's movement No. 225: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_225.html\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/ratchet-feed-lever-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=ratchet-feed-lever-mechanism\n",
 "sources": [
  {
   "publisher": "Henry T. Brown (1868, public domain)",
   "title": "Five Hundred and Seven Mechanical Movements — scan on archive.org",
   "url": "https://archive.org/details/fivehundredseven00browiala",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "507movements.com",
   "title": "Brown's movement No. 225: figure, his text and an animation",
   "url": "https://507movements.com/mm_225.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "ratchet-wheels",
  "ratchet-feed-pawl-24t-d40",
  "ratchet-feed-arm-30",
  "dowel-pins-metric"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "How does a pawl lever step a ratchet wheel?",
   "a": "A lever swinging on the wheel's shaft carries a pawl: on the working stroke the pawl pushes a tooth's steep face and turns the wheel; on the return it rides back over the sloping backs. Rocking becomes step-by-step rotation, one or more teeth (15° each for 24 teeth) per stroke."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "ratchet-feed-lever-mechanism-assembly",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/ratchet-feed-lever-mechanism/ratchet-feed-lever-mechanism-assembly.step",
   "stl": "https://xemstudio.com/files/hardware/ratchet-feed-lever-mechanism/ratchet-feed-lever-mechanism-assembly.stl",
   "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/ratchet-feed-lever-mechanism/index.md"
}