| YEAR | BOTTOM | TOPICS |
|---|---|---|
| 1966 |  |
|
| 1967 |
|
The patent on flint tube bushing, No.2517191 which was issued on Aug. 1, l950, was expired on Aug. 1, l967. The patent number was eliminated from marking on the bottom and the insert. |
| 1968 |  |
|
1969 |
|
As the new press machine was introduced, the indent of the bottom became deeper, and the typeface of "Z" in the Zippo logo was also changed. |
1970 |
 |
In the early1970s the straight cam spring was replaced with a widespread cam spring. |
1971 |
 |
Around this year (1968 - 1972), there were some Zippo using the "solid felt cell" in substitution for a "rayon ball". |
1972 |
|
The 40th Anniversary lighter was produced to customers and employees. |
| 1973 |  |
|
| 1974 |  |
|
| 1975 |  |
|
| 1976 |  |
From 1976, Zippo began placing some instructions on the reverse side of the insert. |
| 1977 |  |
|
| 1978 |  |
|
| 1979 |  |
