Patent
Patentdatenbank China 1987

- Patent:CN85108747 17.06.1987 : Method For Monitoring Multilayer Media Membrane With Ellipsograph
- Patent:CN85108776 03.06.1987 : Slide Rule Of Prime Number-Complex Prime Number
- Patent:CN86202941u 04.02.1987 : Multipurpose Ellipsograph
- Patent:CN86204400u 08.07.1987 : Three In One: Compasses, Ellipsograph And Curve Gauge
- Patent:CN86206968u 28.10.1987 : Slide Rule For Fluid Infusion As Burn
- Patent:CN86207068u 07.11.1987 : Hardness-Test Slide Rule
- Patent:CN86210645u 31.10.1987 : Circular Slide Rule For Converting Electric Level
- Patent:CN87204140u 21.10.1987 : Cross Track Ellipsograph