Ratchet wheel stepped by a swinging pawl lever — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/ratchet-feed-lever-mechanism/  (CC BY 4.0)
Basis: Xem Studio design following Brown No. 225 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- 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.

parameter  value
wheel  24 T, Ø40 (catalog)
step  15° per tooth
pawl pivot radius  30 mm

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 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
- 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

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/ratchet-feed-lever-mechanism/index.json
API: https://xemstudio.com/api/geometry?object=ratchet-feed-lever-mechanism