| 摘要 |
<p>In the past, the ease of assembly in calibration mechanisms of the cam-type for pressure switches has not been acceptable. The present invention greatly improves the ease of assembly. The invention is used for actuating and calibrating pressure-type switches. A calibration mechanism (10) for a pressure switch (12) of the type utilizing a rotary cam (16) controls the setting of a spring-biased plunger (22) to establish pressure levels required to actuate the switch (12). The calibration mechanism (10) includes a support bracket (20) mounted on the switch (12) and a cam assembly including an integrally formed cam member (16) and a camshaft (18). A plunger adjustment mechanism includes a pivotally mounted lever (14) having a cam follower (42) in following engagement with the cam (16). The support bracket (20) defines a bore (50) adapted to receive the camshaft (18). The cam (16) has a range of rotational orientations in which the cam follower (42) engages the operative portion of the cam profile. The camshaft (18) includes a projection (56) extending radially therefrom which is axially disposed from the cam (16) a predetermined distance greater than the axial length of the bore (50) in the support bracket (20). The support bracket (20) defines a slot (54) extending from the bore (50). The cam assembly is assembled to the support bracket (20) by orienting the cam assembly relative to the bracket (20) such that the projection (56) on the camshaft (18) passes through the slot (54) as the camshaft (18) is inserted in the bore (50). The cam assembly is then rotated to the operable range of angular displacement in which the projection (56) is angularly offset from the slot (54), thus axially retaining the shaft (18) of the cam assembly in the bore (50) of the support bracket (20).</p> |
