艺术
美容与健康
工艺
文化与历史
娱乐
环境
食品与饮料
逆向工程
科学
体育
技术
可穿戴设备
The Lever-and-Stirrup Bootjack: One Pull Holds Toe and Heel
Martin

创建者

Martin

30. 九月 2026NO
28
0
0
0
0

The Lever-and-Stirrup Bootjack: One Pull Holds Toe and Heel

A plain bootjack grips only the heel, so a tight boot rocks forward and has to be held down with the other foot. Sardis Thomson of Hartsville, Massachusetts, received US 8,865, dated 6 April 1852, for a boot-jack with "a movable heel-gripper sliding in a stand connected with a toe stirrup and lever by a connecting rod, which stirrup when the foot is placed upon the stand is drawn over the toe by the lever, at the same time drawing the heel gripper forward, and crowding the foot forward in the stirrup, thereby confining the boot in the machine". This rung works out the lever's pull on the heel gripper, then builds the jack from board, dowel and flat bar and times taking a boot off.
中级
About 4 hours

说明

1

Lever force on the heel gripper

正在加载 Jupyter 笔记本…
2

Why the long handle

The embedded blueprint works out the lever law. Thomson's long handle and short rod arm put a strong, short push on the heel.
3

Read US 8,865

"The construction is as follows, A is the stand on which the foot is placed, B is the sliding heel gripper, which has play backward and forward in the slot C, the stirrup D extends below the stand forming in connection with the handle staff E a lever, having the fulcrum at F, and is connected with the heel gripper by the connecting rod G." "It will be seen that the heel-gripper may be made stationary and the connecting rod G dispensed with, and the foot placed upon the stand and drawn back against the heel-gripper, and the stirrup operated as above described; but I prefer the movable gripper and connecting rod as making a more perfect apparatus."
4

Build the jack and take a boot off

**Stand.** Saw a board 45 × 12 cm from hardwood board. Rout or saw a slot 1 cm wide and 12 cm long down its middle, starting 15 cm from the back end. Screw a block across the back end as the rest for the other foot. **Heel gripper.** Cut a hardwood block 10 × 6 × 4 cm, cut a curved notch in its front for the heel, and hold it on the stand with a bolt through the slot so it slides. **Stirrup and lever.** Bend 40 cm of 25 × 3 mm mild steel flat bar into a U wide enough to pass over a boot's toe. Bolt its two ends to the sides of the stand's front end so it swings: that is the fulcrum. Bolt 80 cm of wooden dowel to the top of the U as the handle. **Rod.** Join the U, 5 cm below its pivot, to the gripper's bolt with 35 cm of steel rod, bent into an eye at each end, so drawing the handle back pulls the stirrup over the toe and pushes the gripper forward. **Test.** Wearing a rubber boot, put it on the stand and draw the handle back; hook the spring scale to the handle once to read your pull. Time taking the boot off, and compare with a plain boot jack.

此步骤所需材料:

硬木板硬木板1 个
硬木块硬木块1 个
低碳钢扁钢低碳钢扁钢0.4 米
木榫钉木榫钉0.8 米
低碳钢圆棒低碳钢圆棒0.35 米
六角螺栓组合六角螺栓组合1 个
六角螺母六角螺母4 个
平垫圈平垫圈6 个
木螺钉木螺钉4 个

所需工具:

手锯手锯
钢丝锯(曲线锯)钢丝锯(曲线锯)
充电式电钻充电式电钻
钻头套装钻头套装
台虎钳台虎钳
锤子锤子
圆嘴钳圆嘴钳
活动扳手活动扳手
螺丝刀套装螺丝刀套装
测力计(弹簧秤)测力计(弹簧秤)
秒表秒表
橡胶靴橡胶靴
脱靴器脱靴器
5

A jack that binds, slips or will not hold the toe

Lever-and-stirrup bootjack troubleshooting.

Flow

Loading...
6

History and honest limits

**Sardis Thomson** of Hartsville, Berkshire County, Massachusetts, received US 8,865, dated 6 April 1852. The lever was thrown forward at about sixty degrees to start, the other foot rested on a projection at the back, and he noted that the gripper could be made fixed if simplicity mattered more than grip. His claims cover the heel gripper and stirrup worked by the lever, and the movable gripper with its connecting rod. **Honest limits.** Board, flat bar, dowel and steel rod stand in for his cast stand, stirrup and staff. The notebook ignores friction and the rod's angle; its pull and lengths are examples. Your times are the result.

材料

9

所需工具

13

CC0 公共领域

此蓝图以 CC0 协议发布。你可以自由复制、修改、分发和使用此作品,无需征得许可。

通过购买蓝图中的产品支持创客,他们将获得 创客佣金 (由供应商设定),或创建此蓝图的新版本并将其作为连接包含在你自己的蓝图中以分享收入。

讨论

(0)

登录 加入讨论

加载评论中...