PAUL R HOFFMAN
Engineers in Exton, PA

4534562, Aug 13, 1985

Jun 7, 1983

6/502050

Richard A. Cuff - Rosemont PA
Paul R. Hoffman - Exton PA

Tyler Griffin Company - Paoli PA

A63F 114

273149P

Playing cards are marked with binary codes adjacent both side edges of the face of each card in a standard deck. The code includes a precode which signals a card reader to read the code in proper bit sequence depending on the direction of card movement past the reader. The binary code includes six bits to represent face value and suit of the card, and a four-bit error detection code which can detect errors of two bits in the code. A deck of coded cards is dealt either manually or automatically according to at least one predetermined program. The coded cards are passed over photocells which read the binary codes on the face of the card. The photocell outputs are sent to a microprocessor, which compares the code to the predetermined program and directs the card to the appropriate player location.

4005435, Jan 25, 1977

May 15, 1975

5/577667

David E. Lundquist - Birmingham MI
Paul R. Hoffman - Exton PA
Benjamin T. Sung - Southfield MI
Steven A. Eichhardt - Bloomfield Township MI

Burroughs Corporation - Detroit MI

G01D 900, G01D 1518, B01F 1500

346 1

A generator for producing droplets of liquid by subjecting a confined body of such liquid to varying pressures at a given frequency and causing such liquid to issue from a discharge orifice first as a continuous stream and thereafter to break up into a succession of separate droplets. A particular use of the generator is to produce a controlled stream of ink droplets for the purpose of forming printed characters on documents. It accomplishes this object by making use of acoustic and ultransonic vibrations in a body of ink contained in a cavity of tapering dimensions having an ink intake passage and a discharge orifice, and causing periodic variations (or varicosities) in the hydraulic pressure at the discharge orifice which in turn causes the issuing stream of ink to break up into uniformly spaced apart fine droplets of ink. The droplet forming generator includes a resonant vibrating system composed of tapered front and rear horns having their wider ends in surface contact with the opposite sides of a crystal transducer sandwiched therebetween. The ink at the wider end of the cavity receives the pressure oscillations from the front horn and such pressures are concentrated by the shape of the cavity into the immediate region of its discharge orifice.

3972051, Jul 27, 1976

Oct 24, 1975

5/625811

David E. Lundquist - Birmingham MI
Arvin D. McGregor - Birmingham MI
Paul R. Hoffman - Exton PA

Burroughs Corporation - Detroit MI

G01D 1518

346 1

A laminar air flow passageway through which ink droplets are directed before striking a moving print medium, having a portion of the passageway contoured to expand toward the print medium for slowing a column of air passing therethrough before the column reaches the document. Air suction apertures located in the expanded portion of the passageway and near the print medium provide withdrawal of the airflow to prevent air buildup at the document interface and to maintain laminarity as the air slows. A separate embodiment includes a single air suction aperture located in the upper portion of a gently expanding air passsageway for airflow withdrawal.

4359763, Nov 16, 1982

Aug 4, 1980

6/174921

Paul R. Hoffman - Exton PA

Exxon Research and Engineering Co. - Florham Park NJ

G11B 5016, G11B 554, G11B 2108

360 99

An improved floppy disc drive, with direct disc rotational drive, characterized by a step motor having a plurality of pole pairs with pole pieces fabricated from a portion of the drive housing at predetermined locations, and a disc having radial webs and positioned so that pairs of such radial webs align one pair at a time with successive ones of successively energized pole pairs, thereby providing a highly efficient and compact disc drive motor. The drive assembly also contains a read head drive with a step motor and transmission means for driving the read head radially with respect to the floppy disc. Means are provided which enable clutch operation to engage the disc with the drive only when the disc is properly seated within the drive assembly.

4275426, Jun 23, 1981

Mar 12, 1979

6/019901

Paul R. Hoffman - Exton PA

Exxon Research & Engineering Co. - Florham Park NJ

G11B 5016, G11B 554, G11B 2504

360 99

An improved floppy disc drive, with direct disc rotational drive, characterized by a step motor having a plurality of pole pairs with pole pieces fabricated from a portion of the drive housing at predetermined locations, and a disc having radial webs and positioned so that pairs of such radial webs align one pair at a time with successive ones of successively energized pole pairs, thereby providing a highly efficient and compact disc drive motor. The drive assembly also contains a read head drive with a step motor and transmission means for driving the read head radially with respect to the floppy disc. Means are provided which enable clutch operation to engage the disc with the drive only when the disc is properly seated within the drive assembly.