| US Patent: 51,421 
 | 
| Improvement in machinery for forming sheet-metal ware | 
| 
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
 | 
| Patent Dates: |  
| Granted: | Dec. 12, 1865 |  USPTO (New site tip)
 Google Patents
 Report data errors or omissions to steward 
                        Jeff Joslin
 
 | 
| 
| Description: |  | This machine stamps out sheet metal items. In the then-current state of the art, a press was used with a single female die and a progressive series of male dies, each one forcing the metal a little farther into the female portion of the die. The female die was made of cast iron and the male dies were made of a tin-antimony alloy. The male dies must be recast frequently due to wear, and the whole process was time-consuming. Bray's machine provided several improvements. The sheet-metal blanks are automatically fed into the machine; after being cut the blanks are held at the out edge to force the die to stretch, rather than fold, the metal; providing an adjustment to the pressure on the edge of the blank to accommodate different thicknesses of sheet metal. |  |