| Number | Name | Date | Kind |
|---|---|---|---|
| 1580310 | Lepley | Apr 1926 | |
| 2626721 | Lodge et al. | Jan 1953 | |
| 5090515 | Takahashi et al. | Feb 1992 |
| Number | Date | Country |
|---|---|---|
| 4-361968 | Dec 1992 | JPX |
| Entry |
|---|
| Strackosch, G.R.; "Vertical Transportation: Elevators and Escalators"; pp. 472-475; New York: 1983. |