180
160
140
120
100
80
60
40
20
0
1
TABLE E (Cont.)
Patents registered in Hong Kong 1980 1990
2
3
Class E
เก
5
6
21
01
02
Section E Fixed Constructions
Construction of roads, railways and bridges
Hydraulic engineering; Foundations; Soil shifting
03
Water supply; Sewerage
04
Building
05
Locks; Keys; Window and door fittings; Safes
06
se
21
Doors; windows; shutters or roller blinds in general; Ladders Mining
69