US Patent: 601,451
|
| Lifting-jack
|
|
Patentee:
|
|
| Henry Minor Stevenson (exact or similar names) - Perry, IA |
| Manufacturer: |
| Not known to have been produced |
|
|
Patent Dates:
|
| Applied: |
Apr. 21, 1897 |
| Granted: |
Mar. 29, 1898 |
USPTO (New site tip)
Google Patents
Report data errors or omissions to steward
Jeff Joslin
|
|
Description: |
| This patent uses a recirculating-ball mechanism to create a screw-jack. This constitutes the earliest known patent for what is now called a ball screw, an invention that has become very important in the 21st century in the design of high-precision machinery with X-Y positioning, including many CNC machines. Stevenson did not invention the recirculating-ball mechanism; although the patent does not mention it, an earlier patent, Brunthaver's 477,642, would seem to be the first appearance of recirculating balls in a screw mechanism. |
|
