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The Weight-Closed Bootjack: Lean on Your Toes and the Jaws Close
A bootjack with movable jaws usually closes them by a spring or a hand lever, and a spring strong enough to hold a boot is hard to open.
Henry N. De Graw of Green Island, New York, received US 23,015, dated 22 February 1859, for a bootjack in which a swinging platform is connected to two movable jaws by a guide piece, "of such a construction that the jaws open and close by raising or depressing the front end of the platform without the aid of springs", by "applying more or less weight to the heel or to the toes of the foot which rests on the platform."
This rung works out how the standing foot's weight becomes grip on the heel, then builds the jack in plywood and hardwood and tries it with a rubber boot.
Juu
About 5 hours
Maagizo
1
1
From body weight to jaw grip
From body weight to jaw grip
Inapakia daftari la Jupyter…
2
2
The inclined slot
The inclined slot
The embedded blueprint splits stone with a wedge. De Graw's inclined slots work the same way, turning a downward push into a sideways one.
3
3
Read US 23,015
Read US 23,015
"D, is a swinging platform which has its bearings in side pieces E, which are attached to the bottom about two thirds of its length from the front end of the same, and the platform D, rests on pivots c, so that it can be moved up and down freely."
"The guide piece G, works into a mortise e′, in the bottom A, of the boot jack and it is obvious that by depressing this guide piece the back ends e, of the jaws are forced apart and consequently the jaws will close and by raising the guide piece the back ends are brought closer together and the jaws open."
4
4
Build the jack and try it
Build the jack and try it
**Bottom.** Saw a bottom 50 × 15 cm from plywood and screw a leg under its back end so it slopes. Cut a mortise 5 × 2 cm through it about 15 cm from the front.
**Jaws.** Saw two jaws 20 × 3 cm from hardwood board and bolt each to the bottom's front end through its middle, so the front ends open and close round a heel and the back ends reach the mortise.
**Platform.** Cut a platform 30 × 12 cm. Screw two side blocks to the bottom about two thirds of the way back and pivot the platform on a length of dowel through them.
**Guide piece.** Cut a plywood tongue that hangs from the platform's front end down through the mortise. Cut two slots in it, sloping at 30° from vertical and apart at the bottom, and put a bolt through the back end of each jaw into its slot, so pressing the platform down spreads the back ends and closes the jaws. Put a light compression spring under the platform's front to lift it.
**Test.** Stand one foot on the platform, heel back, and set the other boot's heel between the jaws. Lean onto the toes of the standing foot and check the jaws close; lean back and check they open. Time taking the boot off.
Vifaa kwa hatua hii:
Bati la mbao za kubandika1 kipande
Ubao wa Mti Mgumu1 kipande
Vijiti vya mbao ngumu0.2 mita
Mkusanyiko wa bolti za pembe sita1 kipande
Nati ya pembe sita4 vipande
Washa bapa8 vipande
Parafujo za mbao8 vipande
Mkusanyo wa spring za mgandamizo1 kipandeZana zinazohitajika:
Msumeno wa mkono
Msumeno wa kukata mikunjo
Kekee cha Betri
Seti ya vichimbuzi
Tupa (Tupa ya Mkono)
Kipima-pembe
Spana inayoweza kurekebishwa
Seti ya bisibisi
Rula
Saa ya kupima muda
Buti za mpira
Kivua buti5
5
Jaws that will not close, stick or grip too hard
Jaws that will not close, stick or grip too hard
Weight-closed bootjack troubleshooting.
Flow
Loading...
6
6
History and honest limits
History and honest limits
**Henry N. De Graw** of Green Island, Albany County, New York, received US 23,015, dated 22 February 1859. His jaws were pivoted to the bottom's front end with a cross brace, the back ends were twisted to match the inclined slots, and a spiral spring balanced the platform. He wrote that jacks with movable jaws were not new; his claim is the guide piece worked by the swinging platform.
**Honest limits.** Plywood, hardwood, dowel and bolts stand in for his parts, and a compression spring for his spiral spring. The notebook ignores friction and the spring; its weights, lengths and angles are examples. Your trial is the result.
Vifaa
8- 1 kipandeKishikilia Nafasi
- 1 kipandeKishikilia Nafasi
- 0.2 mitaKishikilia Nafasi
- 1 kipandeKishikilia Nafasi
- 4 vipandeKishikilia Nafasi
- 8 vipandeKishikilia Nafasi
- 8 vipandeKishikilia Nafasi
- 1 kipandeKishikilia Nafasi
Zana Zinazohitajika
12- Kishikilia Nafasi
- Kishikilia Nafasi
- 1 vendor sell this, none ship to you yetKishikilia Nafasi
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Blueprint zinazohusiana
Blueprint hizi zinashiriki maarifa — mbinu, vifaa au kanuni
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