Number | Name | Date | Kind |
---|---|---|---|
2998260 | Meyer | Aug 1961 | A |
3281971 | Weitzner | Nov 1966 | A |
3526976 | Jacobs | Sep 1970 | A |
4146241 | Stevenson | Mar 1979 | A |
4150499 | Wang | Apr 1979 | A |
4666168 | Hamill et al. | May 1987 | A |
4932675 | Olson et al. | Jun 1990 | A |
5314199 | Olson et al. | May 1994 | A |
5340132 | Malewicz | Aug 1994 | A |
5507506 | Shadroui | Apr 1996 | A |
5513862 | Chuang | May 1996 | A |
5662338 | Steinhauser, Jr. | Sep 1997 | A |
6120038 | Dong et al. | Sep 2000 | A |
6135463 | Wrike | Oct 2000 | A |
Number | Date | Country |
---|---|---|
9307938 | Apr 1993 | WO |
Entry |
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“Inside the Switchit Interchangeable Skate” Nov. 1991, Popular Mechanics, p. 50. |