هنر
زیبایی و سلامت
صنایع دستی
فرهنگ و تاریخ
سرگرمی
محیط زیست
غذا و نوشیدنی
مهندسی معکوس
علوم
ورزش
فناوری
پوشیدنیها

The Weeding Claw: A Wire Fork That Grips, Then Levers
A weed pulled by hand snaps at the root and grows back. A tool that grips it low and levers it out takes the root too.
John F. Turner of Philadelphia received US 203,798, dated 14 May 1878 (filed 30 March 1878), for a weeding implement: "a claw formed of wire, for readily pulling or removing weeds, grass, &c., without cutting them", curved back towards the handle with rounded inner faces, and teeth for loosening the earth.
This rung computes how much the claw's lever multiplies a pull, then measures weeds pulled by hand and levered with a claw.
مبتدی
About 1 hour
دستورالعملها
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1
Straight pull against lever
Straight pull against lever
در حال بارگذاری دفترچهٔ Jupyter…
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2
Why raising the handle helps
Why raising the handle helps
The embedded blueprint balances weight and distance on a lever; the claw's curved back is the fulcrum.
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3
Read US 203,798
Read US 203,798
"My invention consists of a claw formed of wire, for readily pulling or removing weeds, grass, &c., without cutting them. It further consists of means for loosening the earth and weeds, and pulling or removing the latter."
The claw is "curved rearward or toward the handle, and formed of two pieces of wire", so that its inner faces are rounded. "When weeds, grass, &c., are to be pulled or removed, the claw is brought thereagainst, and the handle drawn toward the operator, so as to embrace the weeds".
"Should the weeds, grass, &c., be difficult of removal, the handle may be raised so that the claw turns on its outer curved face, the leverage thus exerted quickly overcoming the resistance of the weeds".
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4
Weeding, as a program
Weeding, as a program
فضای کاری Blockly
Loading Blockly workspace...
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5
Measure the pull
Measure the pull
Pick three weeds of the same kind. Tie a loop of string round the first at ground level, hook the force meter to it, and pull straight up slowly, reading the peak. Note whether the root came out or the stem snapped.
Lift the second with the claw as in the program and note whether the root came whole. Loosen the soil round the third first, then pull it with the force meter again. Compare the forces and the roots.
مواد مورد نیاز این مرحله:
بند1 قطعهابزارهای مورد نیاز:
ابزار دستی وجین
بیلچهٔ باغبانی
نیروسنج (ترازوی فنری)
دستکش کار چرمی6
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Weeds that snap, slip or come back
Weeds that snap, slip or come back
Weeding troubleshooting.
Flow
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History and honest limits
History and honest limits
**John F. Turner** of Philadelphia filed US 203,798 on 30 March 1878; it is dated 14 May 1878.
**Honest limits.** The lever model treats the claw as rigid and the fulcrum as a point; soil gives under it and roots break before they come out. Forces and lengths are examples. Your force-meter readings are the measurement.
ابزارهای لازم
4- جایگزین
- جایگزین
- جایگزین
- جایگزین
نقشههای مرتبط
این نقشهها دانش مشترکی دارند — تکنیکها، مواد یا اصول
CC0 مالکیت عمومی
این نقشه تحت مجوز CC0 منتشر شده است. شما آزاد هستید آن را کپی، ویرایش، توزیع و برای هر هدفی بدون نیاز به اجازه استفاده کنید.
با خرید محصولات از طریق نقشه از سازنده حمایت کنید و او کمیسیون سازنده تعیین شده توسط فروشندگان، دریافت میکند یا یک نسخه جدید از این نقشه ایجاد کنید و آن را به عنوان اتصال در نقشه خود قرار دهید تا درآمد به اشتراک گذاشته شود.


