JOHN K GRADY
Electrician in Harvard, MA

4744017, May 10, 1988

Aug 24, 1987

7/088702

John K. Grady - Harvard MA

H02M 7155

363 8

A high tension power supply for use in an x-ray tube drive circuit which uses a step-up transformer to raise an input line signal to the desired voltage level. A partially open bridge or other suitable means permits only half cycles, for example positive half cycles, of the transformer output to be applied to fire the x-ray tube. Saturation of the transformer core during unused half cycles, for example negative half cycles, is prevented by adding a compensating impedance in series with the circuit passing the unused half cycle to the transformer primary, the increased voltage drop across this impedance as current increases in response to the transformer approaching saturation reducing the voltage across the transformer so as to maintain the average voltage across the windings during both half cycles substantially equal. This achieves "constant phase" exposures without transformer saturation.

8427080, Apr 23, 2013

Mar 28, 2011

13/072882

John K. Grady - Harvard MA, US

H05B 37/02

315360, 315308

Applicant has disclosed a method for controlling on and off times for streetlights by synchronizing these intervals to recent local daylight conditions without any human intervention. The preferred method comprises: sensing, via a photocell, when dusk and dawn occurs; and then, timing or counting the dusk and dawn times per 24-hour cycle, recording that dusk and dawn data, calculating the average dusk-to-dawn interval for a plurality of preceding 24-hour cycles; predicting, the next dusk time; and turning on the streetlight for a preselected percentage of the calculated average dusk-to-dawn interval. Future “on” time periods are repeatedly calculated as a percentage of the dark periods determined on one or several immediately prior nights, and so varies with the seasons. Unlike the prior art, Applicant's streetlight control does not require field programming or field inputs from the installer or time knowledge. It also does not require any external or internal precision clock or calendar.

7300205, Nov 27, 2007

Nov 27, 2006

11/563260

John K. Grady - Harvard MA, US

H05G 1/06

378198, 378197

An “Angio Capable Portable X-Ray Fluoroscopy Unit with Sliding C-Arm and Variable Pivot Point” is disclosed. It is a new Portable C-Arm x-ray system for fluoroscopy (e. g. , angio fluoroscopy) that permits head-to-foot, or cranio-caudal, angulation without appreciable degradation or rotation of the recorded image in the segment of possible views most desired to be used for cardiac angiography, generally between a vertical beam and 60 degrees to the patient's left side from vertical. Applicant's preferred embodiment comprises an portable x-ray device of the type having a C-arm which “slides” through a fixed C-slider housing or sleeve mounted onto a portable base, wherein: the C-slider housing is mounted onto the portable base through a rotatable tilt bearing, and the rotation axis of the bearing and fixed sleeve can be repositioned, within an arcuate slot in the base, from approximately horizontal, when the x-ray beam is vertical, to between approximately 60 degrees and 40 degrees below horizontal in a vertical plane.

2012020, Aug 9, 2012

Feb 4, 2011

13/020842

John K. Grady - Harvard MA, US

H02P 7/14, H02J 7/14, B60L 1/00

318293, 307 101, 320119

Applicant has disclosed a method and apparatus for a bipolar automotive electrical system. In the preferred “apparatus” embodiment, Applicant's bipolar electrical system comprises: two (e.g., 12 V) batteries of equal, but opposite voltage (e.g., +12 V, −12 V), with bipolar outputs; an alternator, responsive to the batteries, which controls electrical charge to the batteries individually; an automotive DC motor connected by a single lead wire to the bipolar outputs from the batteries; and, wherein the reversible motor is run off the bipolar output without the need for any intervening devices between the bipolar command outputs and the motors. Alternatively, the alternator can inherently charge the batteries sequentially with the lowest voltage battery being addressed first. This approach allows heavy loads to be powered by 24 V or 48 V DC, yet the arc voltage to ground is still only 12 V or 24 V DC.

7553080, Jun 30, 2009

Feb 7, 2007

11/672083

John K. Grady - Harvard MA, US

H05G 1/06

378194, 378121

An improved rotating anode x-ray tube housing is disclosed. In the preferred embodiment: a single cable, insulated with Ethylene-Propylene Rubber (“EPR”), has an extended Federal Standard terminal or plug mounted within an extended Federal Standard receptacle, attached to an anode end of the housing; the cable is designed to carry up to approximately 150 kV to power the cathode; and insulation of the plug also insulates the 150 kV from a grounded center portion of the x-ray tube and the anode disk area. The longitudinal axes of the anode and high-voltage plug are parallel to one another. This new configuration allows the cathode plug and receptacle to be moved virtually entirely inside the housing. This results in absolute minimal size of the assembly, and a single cable that exits parallel to the rotational axis of the housing.

2012008, Apr 12, 2012

Oct 7, 2010

12/899769

JOHN K. GRADY - Harvard MA, US

H01R 43/00

29825

Applicant has disclosed an improved method and apparatus for installing electrical junction boxes in embedded concrete construction applications. In the preferred embodiment, a first box (with at least one attached conduit) is embedded in the bottom of a concrete deck at pour, wherein the box has an open bottom covered during the pour. After pouring, the cover is removed to expose the open bottom, through a plane of the deck, without having to break through the concrete. A second box, with an open top, is lifted up and fastened (preferably, screwed) to the embedded first box to complete a preferred electrical junction box. The second box is designed to be exposed to accept surface mount or exposed wiring methods. There is a passage between the first and second boxes for accepting wire pulled through the conduit(s).

4549209, Oct 22, 1985

Jul 6, 1983

6/511226

John K. Grady - Harvard MA
Richard E. Rice - Arlington MA

H04N 718, G03B 4116, H01J 4014

358111

An X-ray system includes an X-ray receptor producing on its area a light image with a finite range of intensities. Two or more video tubes scan the same area of the image to generate corresponding electrical output signals, each tube having a bias electrode controlled by a variable voltage source so that one tube generates output signals whose amplitude corresponds to one portion of the range of light intensities at the image area and the output signals of the other tube correspond to a different range portion of the image area light intensities.

4399551, Aug 16, 1983

Sep 29, 1980

6/191936

John K. Grady - Harvard MA

H01J 3510

378126

An X-ray tube including a chamber enclosing an anode disc rotatable about an axis, and movable transversely with respect to that axis, the tube also enclosing an electron beam source for projecting electrons along a beam directed towards a planar surface of the anode disc. The beam source is disposed so as to direct its beam at an acute angle of incidence to the planar surface of the anode disc and produce X-rays which are thereupon reflected from the anode disc through a window in the chamber.

4896344, Jan 23, 1990

Oct 15, 1984

6/661146

John K. Grady - Harvard MA
Richard E. Rice - Arlington MA

H05G 164

378 99

In an X-ray system in which a source directs X-radiation through a subject to a receptor which produces a secondary planar light image, the light image is projected on the planar input face of a light intensifier after passing through the scanning aperture of a moving mask substantially at the plane of the projected light image. Preferably the system includes a moving X-ray mask with a scanning aperture between the source and receptor and means driving the X-ray and light masks in synchronism with their apertures optically superimposed.

8286617, Oct 16, 2012

Dec 23, 2010

12/977455

John K. Grady - Harvard MA, US

F02P 3/045

123605, 123609, 123618, 123622

Applicant has disclosed an improved dual cycle ignition system for automobiles. In the preferred embodiment, the improved ignition system comprises at least two secondary ignition coils wired in a high voltage “OR” configuration using a single high voltage circuit through a distributor, or alternatively a single plug operated directly from diodes connected respectively to associated secondary coils. The ignition coils are set up to alternate sparks, so that even at 8000 engine RPM, each coil is firing as if operating at 4000 RPM, a speed where conventional highly optimized and inexpensive coils are very effective and can reach their full output.