Seismic Pulse Generator (Patent No: 723425)

Inventor: Glazier, Walter H.

Location: Calgary

Comments: N/A

Description:
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A waveform generator for imparting seismic shock to the earth comprising: a first shaft and a second shaft spaced apart from one another in substantially parallel relationship; a plurality of eccentrically weighted gears of equal size rotatably mounted on each of said first and second shafts; the shafts being spaced such that the gears on each shaft mesh with the gears on the other shaft forming pairs of meshing matching eccentrically weighted gears; a third shaft having a plurality of driving gears mounted thereon, said driving gears linearly varying in diameter from its smallest gear to its largest gear, said third shaft being spaced from said first shaft and said driving gears mounted thereon such that said driving gears mesh with the gears on said first shaft; supporting means for rigidly supporting said shafts; and means to rotate said third shaft whereby each pair of said eccentrically weighted gears rotates at a speed proportional to the size of its driving gear.


2. Apparatus according to claim 1 in which said supporting means includes a flat plate of a character to rest upon the earth.


3. Apparatus according to claim 2 in which sealing means are provided between the periphery of said plate and the earth.

4. Apparatus according to claim 2 in which means are provided to produce a partial vacuum under said plate.

5. Apparatus according to claim 1 in which the eccentrically weighted gears are weighted such that the gears meshing with the driving gears of smallest diameter have the largest eccentric weight and the pair of meshing gears meshing with the largest of the driving gears has the smallest eccentric weight such that equal force is generated by each driven gear.

6. Apparatus according to claim 1 in which the difference in size between any two adjacent driving gears is the same.

7. A waveform generator for imparting seismic shock to the earth comprising: two substantially horizontal shafts spaced apart from one another in substantially parallel relationship; a plurality of eccentrically weighted gears rotatably mounted on each of said shafts, each of said gears having an equal number of teeth and being of the same diameter, the shafts being spaced such that the gears on each shaft mesh with the gears on the other shaft forming pairs of meshing gears; means to rotate each pair of said gears at a different preselected rotational speed; and a supporting member rigidly supporting said shafts.

8. Apparatus according to claim 7 in which said supporting means includes a flat plate of a character to rest upon the earth.

9. Apparatus according to claim 8 in which sealing means are provided between the periphery of said plate and the earth.

10. Apparatus according to claim 8 in which means are provided to produce a partial vacuum beneath said plate.

11. Apparatus according to claim 7 with the addition of a mass M and resilient means supporting said mass from said supporting member such that the resonant frequencies of the mass M are less than the frequencies of the generated waveform and the mass is of approximately the same magnitude of force as the maximum upward force generated.

12. A system for producing a composite seismic waveform having n harmonic components, each component having a known phase, frequency and amplitude which comprises: n pairs of rotatable eccentric weights representing each harmonic component and having axes of rotation in substantially the same horizontal plane, and the axis of rotation of each eccentric weight of each pair being substantially parallel to each other, and arranged such that the plane of the rotation of eccentric weights in each pair being substantially the same; means to counter rotate the eccentric weights of each pair; means to rotate each pair of eccentric weights at the frequency and phase of the harmonic component it represents; a rigid base member; and means to support each said axis rigidly from said base member.

13. A seismic waveform generator comprising: a first pair of similar rotatable eccentric weights having substantially parallel axes in a horizontal plane, means to counter rotate the eccentric weights of said pair in substantially the same plane; a second pair of similar rotatable eccentric weights having substantially parallel axes in a horizontal plane; means to counter rotate the second pair of rotatable eccentric weights in substantially the same plane at a frequency different from the rotational frequency of said first pair; and a rigid base member rigidly supporting the axes of rotation of each eccentric weight.

14. Apparatus according to claim 13 in which means are provided to resist upward movement of said generator from the surface of the earth which includes having a base member which is essentially impermeable to air; means to seal the edges of said member with the surface of the earth, and means to generate a partial vacuum between said member and the surface of the earth.

15. A method of generating a seismic pulse using a plurality of pairs of rotatable eccentric weights in which each weight of each pair is rotatable about horizontal parallel axes which are rigidly connected to a base member which comprises: rotating the eccentric weights of each pair counter to each other; and rotating each pair of eccentric weights at a frequency different from that of any other pair.

16. A seismic waveform generator comprising: a first pair of parallel axes in a horizontal plane; a first and a second arm rigidly mounted to each of said first pair of axes; first and second eccentric weights of equal size on said first arm and second arm respectively; a second pair of parallel axes in a horizontal plane; a third arm on one of said second pair of axes and a fourth arm on the other of said second pair of axes; a third eccentric weight mounted on said third arm and a fourth eccentric weight equal to said third eccentric weight mounted on said fourth arm; means to counter rotate the axes of each pair and means to rotate the axes of said first pair at a frequency different from a rotational frequency of said second pair; and a rigid base member rigidly supporting the ax1s of rotation of each said axis.

17. A seismic waveform generator comprising: a plurality of pairs of rotatable eccentric weights, each pair having substantially parallel axes in substantially a horizontal plane; a rigid base member rigidly supporting the axis of rotation of each eccentric weight; means to counter rotate the eccentric weights of each said pair at a frequency different from the rotational frequency of each of the other pairs.

18. Apparatus according to claim 17 in which the difference in rotational frequency between successive frequencies is constant.