| Number | Date | Country | Kind |
|---|---|---|---|
| 2-4669[U] | Jan 1990 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4325162 | Chambers et al. | Apr 1982 | |
| 4658778 | Gamoh et al. | Apr 1987 | |
| 4809502 | Iida et al. | Mar 1989 | |
| 5011058 | Sapp et al. | Apr 1991 |
| Entry |
|---|
| CSI (Chain Saw Industry) & Power Equipment Dealer, May 1977, pp. 8, 9, 39. |
| "Look, Up in the Sky"; Washington Star, 9-23-77. |