UBUHANZI
UBWIZA N'UBUZIMA
UBUKORIKORI
UMUCO N'AMATEKA
IMYIDAGADURO
IBIDUKIKIJE
IBIRIBWA N'IBINYOBWA
UBWUBATSI BUSUBIRA INYUMA
UBUMENYI
SIPORO
IKORANABUHANGA
IBYAMBARWA
Zigzag Stitch Mechanism
Ralph M. Sharaf · Public domain (expired patent)
Tex

Yaremwe na

Tex

22. Nzeli 2026FO
38
0
0
0
0

Zigzag Stitch Mechanism

The lock-stitch machine already published sews a straight line, and a straight line of thread cannot stretch - which is why early machines could not sew knitted cloth, finish a raw edge, or work a buttonhole. The next rung is a mechanism that swings the needle bar sideways between stitches, driven by a cam turning with the main shaft. **US 1,466,150**, "Zigzag mechanism for sewing machines", Ralph M. Sharaf, filed 2. April 1917, granted 28. August 1923: a cam-driven vibration of the needle bar while the machine stitches, with the throw adjustable. Domestic zigzag machines followed in the 1950s. **You build the motion in wood** - a cam, a follower and a pen drawing the needle's path - then sew both stitches on jersey and pull them until something gives.
Hagati
3 hours

Amabwiriza

1

Cut a cam

From 18 mm plywood cut a 60 mm disc and drill its pivot hole 5 mm off centre: that offset is half the zigzag width. Cut a second disc with a 10 mm offset for a wider stitch.

Ibikoresho by'iyi ntambwe:

Urupapuro rw'ibiti byometseUrupapuro rw'ibiti byometse1 igice

Ibikoresho bikenewe:

Umucumita w'IntokiUmucumita w'Intoki
Icyuma Cyivumbura Kidafite InsingaIcyuma Cyivumbura Kidafite Insinga
Umurongo w'ipimaUmurongo w'ipima
2

Follower and needle bar

Screw a pivoted arm to the board so one end rides on the cam's edge and the other carries a dowel - the needle bar. A spring keeps the follower against the cam. Tape a marker to the dowel.

Ibikoresho by'iyi ntambwe:

Ibitorezo by'imashiniIbitorezo by'imashini4 ibice
Ikusanyirizo ry'imisemburo yikanyizaIkusanyirizo ry'imisemburo yikanyiza1 ikirundo
Inkoni z'IbitiInkoni z'Ibiti1 igice

Ibikoresho bikenewe:

Imbunda y'ifatanyo rishyushyeImbunda y'ifatanyo rishyushye
Ifatiro ry'AmezaIfatiro ry'Ameza
Ikaramu IdasibanganaIkaramu Idasibangana
3

Draw the stitch

Pull a strip of graph paper steadily under the pen while turning the cam by hand, one turn per stitch. Measure the width of the trace; swap cams and repeat. Lock the follower to draw a straight line for comparison.

Ibikoresho by'iyi ntambwe:

Urupapuro rw'ImirongoUrupapuro rw'Imirongo1 urupapuro

Ibikoresho bikenewe:

Umurongo w'ipimaUmurongo w'ipima
Isheme yo gupfundikiraIsheme yo gupfundikira
4

Sew the real thing

Cut six 200 x 50 mm jersey strips. Join them in pairs with a 100 mm seam: straight stitch, zigzag 3 mm, zigzag 5 mm, all at 2.5 mm stitch length.

Ibikoresho by'iyi ntambwe:

UrudodoUrudodo10 metero

Ibikoresho bikenewe:

Imashini yo kudodaImashini yo kudoda
Umukasi w'imyendaUmukasi w'imyenda
Ivanga ry'Ibitambaro bya Jersey bya T-shirtIvanga ry'Ibitambaro bya Jersey bya T-shirt
5

Pull until it gives

Mark 100 mm across each seam. Pull each pair apart steadily by hand and note the marked length when the thread snaps - or when it does not, and the cloth simply stretches.

Ibikoresho bikenewe:

Umurongo w'ipimaUmurongo w'ipima
Umugozi wo GupimaUmugozi wo Gupima
6

Thread geometry and your results

Gupakira ikaye ya Jupyter…
7

History & Context

**What the patent specifies:** a cam-driven mechanism that vibrates the needle bar laterally during stitching, with adjustable throw. **Modern build (derived):** a plywood cam and follower drawing the path, plus real seams for the test. The same sideways swing gave overcast edges, buttonholes and decorative stitches, and cam stacks later let a machine select a pattern. Its limits: a zigzag uses more thread, can tunnel thin cloth if the tension is wrong, and the needle bar's sideways travel puts a limit on machine speed.
Intambwe 7 - Image 1

Ibikoresho

6

Ibikoresho bikenewe

11

Blueprint zijyanye

Izi blueprint zisangira ubumenyi — uburyo, ibikoresho cyangwa amahame

The Lock Stitch Sewing Machine — Mechanized Garment Construction

The Lock Stitch Sewing Machine — Mechanized Garment Construction

na TexFO

Imyenda n'Uruhu

52
0
0
0
0
0

CC0 Umurenge rusange

Iyi blueprint yasohowe munsi ya CC0. Ushobora gukoporora, guhindura, gukwirakwiza no gukoresha nta kwemererwa.

Shyigikira Umuremyi ugura ibicuruzwa binyuze muri Blueprint ye Komisiyo y'Umuremyi byashyizweho n'Abacuruzi, cyangwa kora verisiyo nshya y'iyi Blueprint ukayinjiza nk'isano muri Blueprint yawe kugira ngo musangire inyungu.

Ibiganiro

(0)

Injira kugira ngo ujye mu biganiro

Gutegura ibitekerezo...