| All Patents in class 29/218 |
Patents 16 -
21
of 21
      |
| Number | Date | Patentee | Title | Type |
| 1,350,803 | Aug. 24, 1920 | P.P. Hinckley | Combined Valve-Lifter and Hand-Vise | valve spring tools |
| 1,361,219 | Dec. 07, 1920 | J.J. Bartenstein | Valve Spring Holder | valve spring tools |
| 1,467,567 | Sep. 11, 1923 | G.W. Cary | Valve Spring Manipulating Device | valve spring tools |
| 1,614,301 | Jan. 11, 1927 | W.F. Hobbs | Compound Lever Valve Spring Lifter | valve spring tools |
| 2,119,128 | May 31, 1938 | I.J. Clark | Valve Spring Compressor | valve spring tools |
| 2,533,121 | Dec. 05, 1950 | H.W. Kulp | Valve Spring Compressor | valve spring tools |
