Method of and apparatus for processing vacuum pressure information

• US 5,475,619 A
• Filed: 02/23/1995
• Issued: 12/12/1995
• Est. Priority Date: 02/22/1991
• Status: Expired due to Term

• Current Assignee: SMC Kabushiki Kaisha
• Original Assignee: SMC Kabushiki Kaisha
• Inventors: Ito, Yoshiharu, Saito, Mitsuhiro, Takebayashi, Takashi, Sugano, Shigeru, Nagai, Shigekazu
• Primary Examiner(s): Ramirez, Ellis B.
• Assistant Examiner(s): Stamber, Eric W.
• Application Number:
  US08/393,035
• Time in Patent Office: 292 Days
• Field of Search: 364/558, 364/550, 364/551.01, 364/510, 73/1 R, 73/4 R, 73/4, 73/37, 340/626, 901/40, 414/730, 414/737, 209/537
• US Class Current: 700/301
• CPC Class Codes: B25B 11/005 Vacuum work holders
• CPC Class Codes: G01L 19/12 Alarms or signals

Abstract

A method and an apparatus for electrically processing vacuum pressure information in a vacuum unit. The apparatus basically comprises a vacuum supply mechanism, a detecting device, a determining device, a failure precognition signal generating device and a pressure setting-up device. In the apparatus, pressure values are first detected, and a desired pressure value lower than the maximum pressure value of the detected pressure values is digitally displayed on a display unit. Then, the desired pressure value is stored in a storage unit, and pressure values relative to vacuum, which are detected from the detecting device held in front of a passage which communicates with a vacuum port, are converted into digital signals. Thereafter, the digital signals thus converted are digitally displayed on the display unit. Further, the desired pressure value stored in the storage unit is compared with each of the detected pressure values. When they coincide with each other within a predetermined range, a predetermined signal is generated.

Claims

1. A method of processing vacuum pressure information in a vacuum unit, comprising the steps of:

setting a warning vacuum level;

feeding pressurized air from a poppet valve in the vacuum unit through an ejector and to a sensor;

detecting vacuum levels in the vacuum unit by means of said sensor;

comparing said vacuum levels detected in said detecting step against said warning vacuum level set in the setting step; and

producing an alarm signal when said comparing step indicates that said vacuum levels detected in said detecting step do not reach said warning vacuum level a predetermined number of successive times.

2. A method as recited in claim 1, further comprising the steps of:

setting a differential pressure range; and

producing a control signal while said vacuum levels detected in said detecting steps fall within said differential pressure range.

3. A method as recited in claim 2, wherein said step of setting said differential pressure range is performed by setting said differential pressure range as the maximum of said vacuum levels detected in said detecting step reduced by a predetermined percentage.

4. A method of processing vacuum pressure information in a vacuum unit, comprising the steps of:

setting a warning vacuum level;

feeding pressurized air from a poppet valve in the vacuum unit through an ejector and to a sensor;

detecting vacuum levels in the vacuum unit by means of said sensor;

comparing said vacuum levels detected in said detecting step against said warning vacuum level set in the setting step; and

producing an alarm signal when said comparing step indicates that said vacuum levels detected in said detecting step do not reach said warning vacuum level a certain percentage of times for a predetermined number of comparisons.

5. A method as recited in claim 4, further comprising the steps of:

setting a differential pressure range; and

producing a control signal while said vacuum levels detected in said detecting step fall within said differential pressure range.

6. A method as recited in claim 5, wherein said step of setting said differential pressure range is performed by setting said differential pressure range as the maximum of said vacuum levels detected in said detecting step reduced by a predetermined percentage.

7. A method of processing vacuum pressure information in a vacuum unit, comprising the steps of:

setting a warning vacuum level;

feeding pressurized air from a poppet valve in the vacuum unit through an elector and to a sensor;

detecting vacuum levels in the vacuum unit by means of said sensor;

comparing said vacuum levels detected in said detecting step against said warning vacuum level set in the setting step; and

producing an alarm signal when said comparing step indicates that said vacuum levels detected in said detecting step do not reach said warning vacuum level set in the setting step a certain percentage of times for a predetermined period of time.

8. A method as recited in claim 7, further comprising the steps of:

setting a differential pressure range; and

producing a control signal while said detected vacuum levels detected in said detecting step fall within said differential pressure range.

9. A method as recited in claim 8, wherein said step of setting said differential pressure range is performed by setting said differential pressure range as the maximum of said vacuum levels detected in said detecting step by a predetermined percentage.