Handling aid utilizing vacuum operated counterbalance

Claim 2

A vacuum utilizing handling a aid for lifting heavy objects comprising: a source of relatively high vacuum; a source of relatively low vacuum; a vacuum actuated counterbalance; and a vacuum chuck for contacting and gripping the object to be lifted, said vacuum chuck being connected to said source of high vacuum; said counterbalance being connected to said source of low vacuum by a closed valve and means connecting said chuck and said counterbalance operable upon engagement of said chuck with an object to open said closed valve thereby supplying a vacuum to said counterbalance.

Claim 3

The invention of claim 1 wherein a high vacuum reservoir is connected between said high vacuum source and said chuck and a low vacuum reservoir is connected between said low vacuum source and said counterbalance.

Claim 4

The invention of claim 2 wherein said counterbalance comprises a cylinder having a piston movable therein, said piston having a shaft which extends beyond said cylinder and which is mounted to a first flange fixedly attached to one end of said high vacuum reservoir; said cylinder being fixed to a second flange substantially intermediately the ends thereof, the distal portion of said second flange pivotally mounting said high vacuum reservoir for vertical movement.

Claim 5

The invention of claim 3 wherein the proximal portion of said second flange is mounted to achieve horizontal movement of said high vacuum reservoir.

Claim 6

The invention of claim 1 wherein said counterbalance comprises: a cylinder having first, second and third chambers, a piston in said first chamber; a normally closed two-way vacuum valve having a valve stem positioned within said second chamber and having a first valve head positioned within said first chamber and a second valve head positioned within said third chamber, said third chamber having a connection to said low vacuum source and a by-pass connection to said first chamber, said second chamber being partially open to atmosphere and having means forming a wall of an enclosed part of said second chamber for actuating said valve.

Claim 7

The invention of claim 5 wherein said means for actuating said valve includes a collar on said stem engaging the central portion of a flexible diaphragm which extends to the walls of said second chamber forming an enclosed part of said second chamber which is not open to atmosphere; a spring between said collar and the dividing wall between said second and third chambers wherEby said valve is normally positioned so that atmosphere can enter said first chamber from said second chamber; and means in said enclosed part of said second chamber connecting the same to a source of high vacuum.