1. A material separator comprising:
a mechanical bucket defining an inner volume for receiving material therein, the mechanical bucket adapted to couple to a vehicle, the mechanical bucket movable between a first location and a second location by use of the vehicle;
an agitator removably secured to a bottom portion of the mechanical bucket, wherein the agitator comprises:
a frame;
a plurality of shafts rotatably coupled within the frame and operationally coupled to a motor, wherein axes of the plurality of shafts are substantially parallel and wherein the disc assembly is activated by the motor;
a plurality of scalping agitators coupled to each shaft of the plurality of shafts; and
a plurality of screening spaces each having a predetermined spacing, each spacing of the plurality of screening spaces defined between edges of the plurality of scalping agitators of one shaft and edges of the plurality of scalping agitators of an adjacent shaft, wherein the material received within the bucket and placed on a top side of the agitator rests on the top side of the agitator when deactivated, the agitator adapted to separate smaller material from larger material of the material received within the bucket on the top side of the agitator when activated, the smaller material being passed through the plurality of screening spaces and deposited at the first location and the larger material remaining in the bucket resting on the top side of the agitator; and
a sub-base removably coupled to the bottom portion of the mechanical bucket, the sub-base adapted to removably secure the agitator to the bucket.
2. The material separator of claim 1, wherein the motor is driven to its operating speed at a first predetermined rate upon activation.
3. The material separator of claim 2, wherein the motor is driven to a stop from its operating speed at a second predetermined rate upon deactivation.
4. The material separator of claim 3, wherein the motor operates the agitator at a variable rotational speed.
5. The material separator of claim 1, wherein the mechanical bucket is adapted to rotate for dumping the larger material at the second location.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A device for measuring the position and orientation of a person’s head, comprising
a) a frame element disposable in close proximity to the person’s head; and
b) tracking means disposed on the frame and on the person’s head, for tracking the position of the head relative to the frame.
2. The device of claim 1 wherein the frame element is shaped as a hood.
3. The device of claim 2 wherein the frame comprises a plurality of arcuit members covered by a sheath.
4. The device of claim 3 wherein the arcuate members pivot at a common point so that the frame may collapse.
5. The device of claim 2 wherein the frame is mountable on a chair.
6. The device of claim 1 wherein the frame is mountable on a backpack.
7. The device of claim 1 wherein the head tracking means comprises
a) a transmitter on the person’s head; and
b) at least three sensors on the frame.
8. The device of claim 6, further comprising
a) electronic drivers for the head tracking means;
b) electronic drivers for a hand tracking means for tracking the position or orientation of the user’s hand; and
c) electronic drivers for a display system, wherein the head tracking drivers, the hand tracking drivers and the display drivers are all housed within a single unit which fits inside a backpack.
9. The device of claim 1 wherein the tracking means comprises
a) at least one ultrasonic transducer disposed on the person’s head; and
b) at least three ultrasonic receivers disposed on the frame.
10. The device of claim 3 wherein
a) the tracking means comprises an optical encoder; and
b) the sheath is opaque to light.
11. A device for measuring the orientation of a person’s head for a virtual reality system, comprising at least one accelerometer disposed on the person’s head wherein said accelerometers are the only sensors used for tracking the position and orientation of the person’s head.
12. The device of claim 1, further comprising means for tracking the position and orientation of the person’s hand, wherein the hand tracking means are disposed in close proximity to the person’s head and on the person’s hand.
13. A bicolor liquid crystal display, comprising
a) a first polarizer optically coupleable to a light source;
c) a polarization rotating array;
d) a bicolor analyzer, which passes only a first narrow range of wavelengths at a first polarization angle, and passes only a second narrow range of wavelengths at a second polarization perpendicular to the first polarization angle.
14. A device for providing interchangeable optic elements for use in a display unit of a virtual reality system comprising
a) an expandable frame including
1) a front retaining bezel;
2) a rear retaining bezel: and
3) means for urging the front retaining bezel and the rear retaining bezel together; and
b) at least one optic element which fits inside the expandable frame.
15. A display apparatus suitable for use in a virtual reality system, comprising
a) a light source;
b) a first polarizer optically coupled to the light source;
c) a polarization rotating array optically coupled to the first polarizer;
d) an expandable frame for holding interchangeable optic elements, positioned so that selected optic elements are operably coupled to the polarization rotating array, including
1) a front retaining bezel;
2) a rear retaining bezel; and
3) means for urging the front retaining bezel and the rear retaining bezel together; and
e) at least one lcd analyzer suitable for being inserted into and removed from the expandable frame; and
f) at least one lens suitable for being inserted into and removed from the expandable frame.