IṢẸ́ ỌNÀ
ẸWÀ ÀTI ÌLERA
IṢẸ́ ỌWỌ́
ÀṢÀ ÀTI ÌTÀN
ÌṢERÉ
ÀYÍKÁ
OÚNJẸ ÀTI OHUN MÍMU
REVERSE ENGINEERING
SÁYẸ́ǸSÌ
ERÉ ÌDÁRAYÁ
ÌMỌ̀-Ẹ̀RỌ
ÀWỌN OHUN WÍWỌ̀

The Shouldered-Blade Can Opener: The Shoulders Are the Fulcrum
A hermetically sealed tin can was opened with a knife or a chisel, which slips and tears the metal.
John Willard of Norwich, Connecticut, received US 57,422, dated 21 August 1866, for an instrument for opening tin cans made of one piece of metal: a pointed blade at right angles to the handle, ending in two right-angle shoulders that rest on the can top as the fulcrum and press the cut edges down as the blade advances.
This rung works out the force the lever saves, then forges the opener from flat bar and opens a can with it.
Àárín
About 3 hours
Ìlànà
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Cutting force and hand force
Cutting force and hand force
Ń ṣí ìwé Jupyter…
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2
A lever-knife opener before it
A lever-knife opener before it
The embedded blueprint cuts a can with a lever and a guard. Willard makes blade, fulcrum and handle in one piece, the shoulders resting on the can.
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Read US 57,422
Read US 57,422
"This will bring the shoulders b b upon the top surface of the can, so that these shoulders will serve as a fulcrum when the handle of the knife is depressed, and cause the cutting-edge a' of the blade B to make a slit through the can top."
"The shoulders b b not only serve as the support for the instrument upon the can, but these shoulders also press the edges of the metal down as the instrument is moved up to its work."
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Mark and cut the blank
Mark and cut the blank
Cut 190 mm of 25 × 3 mm flat bar. At one end mark a 10 mm neck 12 mm long, then the 30 mm blade with its point; saw and file the neck, leaving the shoulders full width.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Ọ̀pá Pẹrẹsẹ Irin Pẹ́lẹ́1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Ayùn Irin
Ìdìmú Tábìlì
Àwọn Ìfá (Ìfá Ọwọ́)
Ìdíwọ̀n
Ààmì Tí Kò Ní Parẹ́5
5
Twist the blade
Twist the blade
Grip the neck in the vice and twist the blade a quarter turn with the wrench, so it stands at right angles to the handle.
Àwọn irinṣẹ́ tí a nílò:
Ìdìmú Tábìlì
Kọ́kọ́rọ́ tí a lè ṣàtúnṣe
Ìbọ̀wọ́ Iṣẹ́ Awọ6
6
Grind the edge and point
Grind the edge and point
File the blade's upper edge to a cutting bevel and its end to a sharp point. Finish on the whetstone.
Àwọn irinṣẹ́ tí a nílò:
Àwọn Ìfá (Ìfá Ọwọ́)
Òkúta ìpọ́n
Ìdìmú Tábìlì
Gílásì Ààbò Tí Ó Mọ́7
7
The build in 3D
The build in 3D
FreeCAD model of this build, not of the patent: a 130 mm handle of 25 × 3 mm bar, the shoulders, the 10 mm neck, and the pointed 30 mm blade standing at right angles to the handle.
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Open a can
Open a can
Stand a sealed can on the kitchen scale. Push the point through the top, rock the handle down on the shoulders and advance; read the peak load on the scale and time a full circle.

Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Ìgò irin1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Òṣùwọ̀n Díjítà Ilé Ìdáná
Aago Ìdúró
Ìbọ̀wọ́ Iṣẹ́ Awọ9
9
A blade that tears, skids or will not pierce
A blade that tears, skids or will not pierce
Shouldered-blade can opener troubleshooting.
Flow
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History and honest limits
History and honest limits
**John Willard** of Norwich, Connecticut, received US 57,422, dated 21 August 1866. His handle may be of any length and width; the blade's lower edge may curve upward, and its cutting edge may project above the handle's flat surface so it meets the metal at a steep angle. His claim covers the one-piece opener with blade, shoulders and handle.
**Honest limits.** Mild flat bar does not hold an edge like hardened steel; the notebook's shear strength is an estimate. Your loads and times are the result.
Àwọn irinṣẹ́ tó nílò
11- Àyè
- Àyè
- Àyè
- Àyè
- Àyè
Àwọn fáìlì àpẹrẹ
1Ìtọ́nisọ́nà yìí ń ṣe
Blueprint tó jọra
Àwọn blueprint wọ̀nyí pín ìmọ̀ — ọ̀nà, ohun-èlò tàbí ìlànà
CC0 Àgbègbè Gbogbogbò
Blueprint yìí ti jáde lábẹ́ CC0. O lè ṣe àdàkọ, yí padà, pín, àti lò láìsí ìyọ̀ǹda.
Ṣàtìlẹ́yìn Olùṣẹ́dá nípa rírà àwọn ọjà nipasẹ̀ Blueprint wọn Ẹ̀san Olùṣẹ́dá tí àwọn Olùtajà gbé kalẹ̀, tàbí ṣẹ̀dá àtúnṣe tuntun ti Blueprint yìí kí o sì fi sínú Blueprint rẹ gẹ́gẹ́ bí ìsopọ̀ láti pín owó-wíwọlé.



