Apparatus for holding an object to a surface using valve controlled vacuum force

• US 5,048,804 A
• Filed: 10/09/1990
• Issued: 09/17/1991
• Est. Priority Date: 05/17/1990
• Status: Expired due to Fees

• Current Assignee: FSK, Inc.
• Original Assignee: FSK, Inc.
• Inventors: Ito, Hirotsugu
• Primary Examiner(s): Watson, Robert C.
• Application Number:
  US07/595,357
• Time in Patent Office: 343 Days
• Field of Search: 248/362, 248/363, 269/21, 269/20, 51/235, 294/69 R, 294/69 A, 294/69 B, 294/65, 279/3 R
• US Class Current: 269/21
• CPC Class Codes: B25B 11/005 Vacuum work holders

Abstract

A technique of holding an object, wherein an object (10) to be held is placed on a holding surface (3) having a plurality of suction holes (4), each of which has a valve (6) therein which is operated in accordance with the difference between the pressure in the upper or outer space and the pressure in the lower or inner space demarcated by the valve (6). The valve (6) is opened by utilizing the phenomena that such pressure difference in those suction holes (4) closed by the object (10) becomes smaller, whereas the valves (6) are closed by utilizing the phenomena that such pressure difference in those suction holes (4) which are not closed by the object (10) and remain open becomes greater, to thereby prevent reduction of the suction force to be exerted on the object (10).

Claims

1. An apparatus for holding an object to a surface, comprising:

means defining a surface (3) for receiving an object to be held thereon, said means having a plurality of suction holed (4) therein and a vacuum source (2) coupled to said suction holes (4) to apply a suction force to said suction holes;

valve means (6) in each of said suction holes (4), said valve means (6) being located between the outer space above said object receiving surface (3) and said vacuum source (2), said valve means (6) each being operable in accordance with a difference between a pressure in an outer space above said object receiving surface (3) and the pressure in an inner space within said vacuum source (2);

said vacuum source comprising a vacuum chamber (2) below said suction holes (4) and valve means (6);

biasing means for biasing the respective valve means (6) toward an open position at which communication is provided between said vacuum source (2) and said outer space via said valve means (6) and suction holes (4) and wherein the valve means (6) is opened when a pressure difference in those suction holes (4) closed or covered by an object (10) becomes smaller than a predetermined value, and wherein said valve means (6) is closed to stop communication between said vacuum source (2) and said outer space when the pressure difference in those suction holes (4) which are not closed by the object (10) and remain open becomes greater than a predetermined value, to thereby prevent loss of suction force to be exerted on the object (10) due to suction loss through open suction holes (4); and

said valve means comprising a flexible resilient valve member arranged above a valve seat, said flexible valve member comprising a peripheral leg member for normally spacing said flexible valve member away from said valve seat, said flexible valve member being flexible toward and away from said valve seat responsive to said pressure difference, and said flexible valve member being resiliently biased away from said valve seat toward said open position.

2. The apparatus of claim 1, further comprising a projection member at a central portion of said flexible valve member for seating against said valve seat upon resilient deformation of said valve member toward said valve seat responsive to said pressure difference.

3. The apparatus of claim 2, further comprising spring means for biasing said central projection away from said valve seat.

4. The apparatus of claim 1, wherein said flexible valve member comprises a flexible sheet-like valve member having at least one opening therein.

5. An apparatus for holding an object to a surface, comprising:

means defining a surface (3) for receiving an object to be held thereon, said means having a plurality of suction holed (4) therein and a vacuum source (2) coupled to said suction holes (4) to apply a suction force to said suction holes;

valve means (6) in each of said suction holes (4), said valve means (6) being located between the outer space above said object receiving surface (3) and said vacuum source (2), said valve means (6) each being operable in accordance with a difference between a pressure in an outer space above said object receiving surface (3) and the pressure in an inner space within said vacuum source (2);

said vacuum source comprising a vacuum chamber (2) below said suction holes (4) and valve means (6);

biasing means for biasing the respective valve means (6) toward an open position at which communication is provided between said vacuum source (2) and said outer space via said valve means (6) and suction holes (4) and wherein the valve means (6) is opened when a pressure difference in those suction holes (4) closed or covered by an object (10) becomes smaller than a predetermined value, and wherein said valve means (6) is closed to stop communication between said vacuum source (2) and said outer space when the pressure difference in those suction holes (4) which are not closed by the object (10) and remain open becomes greater than a predetermined value, to thereby prevent loss of suction force to be exerted on the object (10) due to suction loss through open suction holes (4); and

said valve means comprising a flexible resilient valve member arranged above a valve seat, said flexible valve member comprising a peripheral leg member for normally spacing said flexible valve member from said valve seat, and a central projection for selectively seating against said valve seat upon resilient deformation of said valve member toward said valve seat responsive to said pressure difference, said flexible valve member being flexible toward and away from said valve seat responsive to said pressure difference, and said flexible valve member being resiliently biased away from said valve seat toward said open position.

6. The apparatus of claim 5, further comprising means for biasing said central projection away from said valve seat.

7. The apparatus of claim 6, wherein said means for biasing said central projection away from said valve seat comprises a spring.

8. The apparatus of claim 5, wherein said flexible valve member comprises a flexible sheet-like valve member having at least one opening therein.