Key for a lock cylinder

Abstract From the Canadian patent

For increased security the key (2; 40; 44) has one or more blade portions (43; 45, 46; 5, 6). The longitudinal central plane (A, B) of the or each blade portion is offset from the guide region (42; 7) running along the back edge of the key shaft (3). Furthermore, the or each blade portion is connected to the guide region by means of a bridging portion (14, 14') which forms an obtuse angle (alpha) with the guide region, as well as forming an obtuse angle with the blade portion. In one preferred embodiment two blade portions (45 46; 5, 6) are provided; they may be of the same cross-sectional shape (Figure 2) or symmetrical (Figure 11). The blade portions and guide region may be divided into …