| 摘要 |
1474636 Cams; linkwork ITT INDUSTRIES Inc 23 Dec 1974 [9 Jan 1974] 55378/74 Heading F2K [Also in Division H1] A rectilinear snap-action mechanism comprises in a frame an input arm 14<SP>1</SP> having camming surfaces 14a<SP>1</SP>, 14b<SP>1</SP> which can engage with detent members 18a<SP>1</SP>, 18b<SP>1</SP> movably mounted in slots in the frame, and an output arm 16<SP>1</SP> having detent slots 16a<SP>1</SP> and 16b<SP>1</SP> into and out of which the detent members can move under the action of the camming surfaces of the input arm and the forces of bias springs 20<SP>1</SP> to hold or release the output arm respectively, both the input and output arms being movable rectilinearly along the same direction in the frame, the arrangement being such that when the input arm is moved initially the output arm is held by the detent 18a<SP>1</SP> whilst a spring 22<SP>1</SP> between the input and output arms is compressed so that when the camming surface 14a<SP>1</SP> on the input arm moves the detent 18a<SP>1</SP> out of the detent slot in the output member to release it, the output member is shot rapidly under the action of the compressed spring 22<SP>1</SP> to follow the input member. The movement of the input and output arms in the frame is constrained by rollers on the arms running in guide grooves in the frame. In a second embodiment, Fig. 12, not shown, to prevent reversal of movement of the input arm whilst the output arm is moving, locking fingers can be provided associated with the camming surfaces of the input arm to trap the detent members whilst the output arm is moving. The output arm operates the contacts of a gas blast switch. |
