| 摘要 |
<p>A sensing apparatus is described for use in a target indicating system operative selectively to signal a strike on a target plate. The target indicating system includes an actuator mechanism adapted to be driven by a pressurized gas, conduit and servo control means in flow communication with the actuator mechanism and adapted, in use, to supply gas under pressure to the actuator mechanism. A strike sensing apparatus or assembly is also included, connectible, in use, to the conduit and servo control means. This sensing apparatus includes a housing defining a cylinder therein having one portion thereof adapted to be in flow communication with the source of pressurized gas. A piston is provided being slidably movable in the cylinder. The piston has a bleed channel therein to depressurize the cylinder. A motionsensitive weight, preferably in the form of a sphere, is supported by the piston and acts on a needle valve to keep the bleed channel closed. This weight is moveable in response to a strike on the target plate, enabling the bleed channel to be uncovered, thereby causing rapid depressurization of the cylinder and a correspondingly rapid lowering of the target. Preferably the weight is a spherical ball and the stem portion of the piston is formed with a spherical seat for supporting said ball. In another preferred form of this apparatus, biasing means are included, supported in the cylinder housing to cause retraction of the piston when the cylinder has been depressurized.</p> |
