Control system

{
  "publication_number": "US3782250A",
  "country": "US",
  "kind": "A",
  "title": "Control system",
  "abstract": "A control system for an air cylinder in which electronic links are used to control a cylinder from a remote location without the delay normally encountered with air transmission lines. Inlet and exhaust valves are electronically activated in response to a pressure measuring device on the air cylinder which produces a voltage signal which signal is compared to a voltage signal generated at the control location.",
  "claims": [
    "1. An air cylinder control system comprising in combination: a source of pressurized air; adjustable inlet valve means connected to said source and operable to admit air to the air cylinder in controlled amounts; adjustable exhaust valve means connected to allow the escape of air from said air cylinder in controlled amounts; pressure measuring means connected to said air cylinder; first electronic control means comprising a potentiometer remotely situated from said air cylinder operable to produce a voltage signal of magnitude proportional to the desired air pressure in said cylinder; second electronic control means comprising a potentiometer connected to said pressure measuring means so as to produce a voltage signal of magnitude proportional to the actual air pressure in said cylinder; first amplifying means comprising operational amplifier circuits driving silicon controlled rectifier circuits connected between said first and second electronic control means to produce a signal indicative of the difference in voltage therebetween and further connected to adjust said inlet valve means in proportion to said difference in voltage magnitude; second amplifying means comprising operational amplifier circuits driving silicon controlled rectifier circuits connected between said first and second electronic control means in opposite polarity to said first amplifying means to produce a signal indicative of the opposite polarity voltage difference therebetween and further connected to adjust said exhaust valve means in proportion to the opposite polarity difference in voltage; diodes between said control means and said amplifying means to insure that said first and second amplifying means respond only to voltage differences of the prescribed polarity and are never activated simultaneously; and a bias resistance connected to said second electronic control means so as to insure that said second control means always presents a signal to said second amplifying means of magnitude at least as large as the electronic threshold voltage necessary to activate said second amplifying means.",
    "2. The apparatus of claim 1 in which said adjustable valve means comprise solenoid operated air valves operable to open in an amount proportional to the voltage signal presented to the solenoids."
  ],
  "cpc": [
    "F15B 21/08",
    "F15B 11/06",
    "F15B 2211/40515",
    "F15B 2211/41572",
    "F15B 2211/426",
    "F15B 2211/455",
    "F15B 2211/46",
    "F15B 2211/6313",
    "F15B 2211/6346",
    "F15B 2211/6653",
    "F15B 2211/7052"
  ],
  "ipc": [
    "F15B 11/06",
    "F15B 21/08"
  ],
  "assignees": [
    "Microdot Inc"
  ],
  "inventors": [
    "R Kiszewski"
  ],
  "filing_date": "1971-11-03",
  "publication_date": "1974-01-01",
  "grant_date": "1974-01-01",
  "priority_date": "1971-11-03",
  "application_number": "US-3782250D-A",
  "family_id": "22720101",
  "cited_by_count": 13,
  "citations": [
    "US3125856A",
    "US2615658A",
    "US3223912A",
    "US3295421A",
    "US3513400A",
    "US3618469A",
    "US3641546A"
  ]
}