| 摘要 |
<p>A valve actuating device (20) of a heating and/or cooling system controls the opening and closing of a valve (22) of the system. The device (20) includes a housing (62) having a fitting (80) which is threadably received by a fitting receiving formation (3A) of the valve (22) for securing the housing (62) to the valve (22). The device (20) further includes an electric motor (86) mounted on the housing (62). The motor (86) drives a shaft (90) having a pinion gear (102) mounted thereon, and, upon its activation, opens the valve (22). A rack (88) has teeth (96) engageable with the pinion gear (102) of the electric motor (86) and an end portion (98) engageable with a valve stem (54) of the valve (22). The arrangement is such that the rack (88) is movable upon activation of the motor (86) from a first position in which the end portion (98) of the rack (88) engages the valve stem (54) for maintaining a valve member (56) of the valve (22) in a closed position, to a second position in which the rack (88) is moved via the pinion gear (102) of the motor (86) away from the valve stem (54) for opening the valve (22).</p> |
