Mechanically actuated vacuum lifting device

A vacuum-assisted lifting apparatus, for lifting load from a support, the apparatus comprising:

• a cylinder housing, adapted for supporting the load, and defining a lifting axis and a cylinder bore extending along the lifting axis;
• a piston having an axial thickness thereof, the piston being sealingly disposed in the cylinder bore and movable axially along the lifting axis, with the piston and cylinder bore, in combination, defining a sealed fluid cavity;
• a control valve attached to the cylinder housing, by a valve support housing, and having a movable seal member thereof operatively disposed for selectively sealing and unsealing the fluid cavity;
• a suction cup device, adapted for gripping the load, and operatively connected in fluid communication with the fluid cavity;
• and
• a piston rod, having first and second axial ends thereof, with the suction cup device being attached to the second end, and the first end sealingly extending through the piston for limited sliding movement through the piston between upper and lower piston rod travel stops axially spaced a rod travel distance apart, and operatively connected to the piston rod, with the rod travel distance being greater than the thickness of the piston, such that
• the piston rod urges axial movement of the piston in the cylinder bore when the piston is contacting either the upper or the lower rod travel stops while a substantially axially directed force is being applied to the piston rod, and such that the piston rod may slide through the piston for operatively contacting and moving the movable seal member of the control valve, in certain predetermined relative orientations of the piston rod, piston and cylinder bore, to thereby seal and unseal the fluid cavity.

A vacuum-assist lifting apparatus, for lifting a load from a support, the apparatus comprising:

• a cylinder housing, a piston, a piston rod, a control valve, a fluid communication conduit, and a suction cup device adapted for gripping the load;
• the cylinder housing, adapted for supporting the load, defining a vertical lifting axis, upper and lower ends of the cylinder housing, and an axially oriented cylinder bore extending along the lifting axis, with the cylinder housing having upper and lower end-of-stroke stops for limiting travel of the piston within the cylinder bore, the cylinder housing also having an annular wall substantially closed at an upper end thereof by an upper end wall, with the upper end wall having a central opening therein;
• the control valve attached to the cylinder housing and having a movable sealing member thereof operatively disposed for selectively opening and closing the central opening in the upper end wall of the cylinder housing;
• the piston defining a thickness of the piston, being sealingly disposed within the cylinder bore for movement axially within the cylinder bore, and having a central hole therein for passage therethrough of the piston rod;
• the cylinder bore, piston, and sealing member of the control valve defining a fluid cavity within the bore above the piston, the fluid cavity being sealed when the sealing member is closing the central opening, and not-sealed when the sealing member is not closing the central opening;
• the fluid communication conduit operatively connecting the fluid cavity to the suction cup device;
• the piston rod having an upper and a lower end thereof and being operatively disposed for movement along the vertical lifting axis with respect to the cylinder bore, with the lower end of the piston rod being adapted for attachment thereto of the suction cup device;
• the piston rod sealingly extending through the central hole in the piston and being operatively coupled to the piston for limited sliding axial movement through the piston between upper and lower piston rod travel stops axially spaced a rod travel distance apart;
• the upper piston rod travel stop being disposed to bear downwardly on the piston, and thereby urge downward movement of the piston with the cylinder bore, when the piston rod is being urged to move downward in the cylinder bore by upward movement of the cylinder housing along the lifting axis while the load is being gripped by the suction cup device or as a result of gravitational force acting on the piton rod and suction cup device;
• the lower piston rod travel stop being disposed to bear upwardly against the piston to thereby urge the piston to move upward in the cylinder bore when the piston rod is being urged to move upward in the cylinder bore by virtue of the cylinder housing being lowered along the lifting axis while the suction cup device is resting on the load or the support;
• the rod travel distance being greater than the thickness of the piston, so that as the piston rod is urged upward in the bore, the piston rod slides through the piston the rod travel distance and the upper end of the piston rod extends upward beyond the piston for contacting the movable sealing member of the control valve, and moving the sealing member to thereby unseal the central opening in the upper wall of the cylinder housing.