| 摘要 |
There is a suction pad (14) in the vacuum gripper, an air flow passage leading from inside the suction pad to the outside of the suction pad and a shut-off valve (22) on the air flow passage. There is a cavity (44) in the shut-off valve and a spindle pin (50) arranged to move in the cavity, in which spindle pin there is a tubular hole (56) in the longitudinal direction of the spindle pin. The first end of the hole opens inside the suction pad and the opening (58) of the second end leads to the cavity. The spindle pin can be brought into a first position, in which the opening in the second end is closed and into a second position, in which the opening in the second end is open. The function of the shut-off valve is thus controlled with the position of the spindle pin. When the suction pad is moved against the surface of the object to be gripped, the surface of the object presses the end of the spindle pin and the spindle pin moves into the second position. An air flow passage opens from inside the suction pad to the outside of the suction pad, when the mouth of the suction pad is pressed against the surface of the object. The air pressure makes the spindle pin to move in the cavity into the first position that closes the air flow passage when the suction pad is not gripping the object, i.e. the surface of the object is not pressed against the first end of the spindle pin. The vacuum gripper is connected to a negative pressure source with a suction tube 24. |
