Pendulous accelerometer and/or inclinometer

• US 4,926,690 A
• Filed: 03/07/1988
• Issued: 05/22/1990
• Est. Priority Date: 03/07/1988
• Status: Expired due to Fees

• Current Assignee: Paul E. Oberg
• Original Assignee: Paul E. Oberg
• Inventors: Oberg, Paul E.
• Primary Examiner(s): Chapman, John
• Assistant Examiner(s): Bell, Robert P.
• Application Number:
  US07/164,558
• Time in Patent Office: 806 Days
• Field of Search: 73/493, 73/495, 73/514, 33/401
• US Class Current: 73/514.37
• CPC Class Codes: G01P 15/032 by measuring the displacement of a movable inertial mass

Abstract

A motion of a first pendulous mass responsive to combinatorial gravitation and acceleration force vectors in a first plane is kinetmatically coupled to cause displacement of an indicator needle in a second plane that is orthogonal to the first plane. Also in an accelerometer/inclinometer, a second pendulous mass moves responsively to combinatorial force vectors in the second plane, and causes displacement of another indicator needle in this same second plane. The first plane is nominally aligned longitudinally in a vehicle while the second plane is aligned laterally. By this alignment each of the longitudinal, or fore-aft, and the lateral, or side-to-side, combinatorial tilts and accelerations of the vehicle are displayed.

Claims

1. A pendulous accelerometer indicating by deflection of an indicator element in an XZ plane a pendulous acceleration undergone by a mass accelerating in a YZ plane that is orthogonal to the XZ plane, the accelerometer comprising:

an X axis shaft, parallel to or coincident with an X coordinate axis;

a first pendulous mass, affixed to the X axis shaft, moving in an arc due to an accelerating force in the YZ plane so as to induce rotation of the X axis shaft;

a first member, affixed to the X axis shaft, defining at an extension from the X axis shaft and between two elements of the first member that are aligned approximately about radial lines from the X axis shaft a region that is capable of laterally interlocking a second member, the first member undergoing movement in the YZ plane corresponding to arcuate movement of the first pendulous mass;

a Y axis shaft, parallel to or coincident with a Y coordinate axis;

an angled helical second member in three dimensions and not in any one plane, affixed at two separated points to the Y axis shaft for an axis of rotation, and extending radially away from the Y axis shaft at these points until, a predetermined distance of separation having been reached, the second member runs along the length of the Y axis shaft at a pitch;

the X axis shaft being located in an plane that is normal to the Y axis shaft and that intersects the Y axis shaft in the region of the second member;

the second member laterally interlocked by the two elements of the first member'"'"'s extended region so that movement of the first member and the two elements of its extended region responsive to X axis shaft rotation causes a corresponding rotation of the second member and of the Y axis shaft.

2. The pendulous accelerometer according to claim 1, with Z axis essentially plumb, further comprising:

a second Y axis shaft, parallel to or coincident with the Y coordinate axis;

a second pendulous mass moving due to an accelerating force in the XZ plane so as to induce rotation of the second Y axis shaft, to which it is affixed, that is perpendicular to the XZ plane; and

a second indicator element within an XZ plane and connected to the second Y axis shaft for undergoing deflection in this XZ plane responsively to rotation of the second Y axis shaft.

3. The pendulous accelerometer according to claim 1 wherein the X axis is parallel to an X axis coplanar with the Y axis but is displaced away from the first member'"'"'s extended region interlocking the second member, therein producing a larger rotation of the Y axis shaft for a given rotation of the X axis shaft than would be the case if the X axis were coplanar with the Y axis.

4. The pendulous acclerometer according to claim 1 wherein the X axis is parallel to an X-axis coplanar with the Y axis but is displaced towards the first member'"'"'s extended region interlocking the second member, therein producing a lesser rotation of the Y axis shaft for a given rotation of the X axis shaft than would be the case if the axis were coplanar with the Y axis.

5. The pendulous accelerometer according to claim 1 wherein the first member'"'"'s extended region is in the shape of a fork, which fork closely laterally interlocks the angled second member passing through the tines of the fork.

6. The pendulous accelerometer according to claim 1 wherein the first member'"'"'s extended region is in the shape of an aperture defined by the first member, which aperture closely laterally interlocks the angled second member passing through the aperture.

7. The pendulous accelerometer according to claim 1 wherein the angled helical second member extends from the Y axis shaft in a three dimensional path which commences by extending essentially radially outward from a first point upon the Y axis shaft to a radial distance of separation therefrom, the path then extending approximately as a helix, meaning a curve traced on a cylinder by the rotation of a point crossing its right section at a constant oblique angle, along an imaginary cylinder coaxial with the first Y axis shaft and of a radius substantially equal to the radial distance of separation, the path then extending essentially radially inward from the radial distance of separation back to a second point upon the first Y axis shaft.

8. The pendulous accelerometer according to claim 1 wherein the rotation induced in the first Y axis shaft by the extended region of the first member interlocking the angled helical second member resultant to the rotation of the X axis shaft is proportional to the tangent of the angle of rotation of the X axis shaft;

therein by the proportional rotation permitting any scale showing the rotation of the Y axis shaft to be linear with the tangent of the angle of rotation of the X axis shaft.

9. The pendulous accelerometer according to claim 1 wherein the relationship of the pendulous mass and the indicator element is such that movement of the pendulous mass in the YZ plane towards the spatial position of the indicator element causes a clockwise deflection of the indicator element in an XZ plane.

10. The pendulous accelerometer according to claim 1 wherein the indicator element comprises:

a pointer needle.

11. The pendulous accelerometer according to claim 1 wherein the Z axis that is within the orthogonal YZ and XZ planes is plumb.

12. An inclinometer indicating, by deflection of an indicator element in an XZ plane, a tilt of the inclinometer in a YZ plane orthogonal to the XZ plane the inclinometer which tilts in one plane and indicates this tilt in another plane comprising:

an X axis shaft;

a mass suspended from the X axis shaft for pivoting in the YZ under force of gravity so as to induce rotation of the X axis shaft perpendicular to this YZ plane when the inclinometer is tilted in the YZ plane;

a first member, affixed to the X axis shaft and extending therefrom to a region where it is capable of mechanically interlocking an element laterally traversing the region;

a Y axis shaft;

a helical second member, affixed to the Y axis shaft for mechanically interlocking the first member as the element laterally traversing its extended region for linearly translating the tangent of the angle of rotation of the X axis shaft into a corresponding angle of rotation of the Y axis shaft that is perpendicular to the XZ plane;

an indicator element within an XZ plane connected to the Y axis shaft for undergoing deflection in the XZ plane responsively to rotation of the Y axis shaft.

13. The inclinometer according to claim 12 further comprising:

a Y axis shaft perpendicular to the XZ plane;

another mass suspended for pivoting under force of gravity in the XZ plane so as to induce rotation of the Y axis shaft; and

another indicator element within an XZ plane connected to the Y axis shaft for undergoing deflection in the XZ plane responsively to rotation of the Y axis shaft.

14. The inclinometer according to claim 13 wherein the suspended mass is accelerated in the YZ plane to induce further, additive, rotation of the X axis shaft to that rotation induced by a tilt of the inclinometer in the YZ plane;

and

wherein the indicator element is undergoing deflection corresponding to combinatorial inclination gravitational vector in the YZ plane and acceleration in the YZ plane.

15. The inclinometer according to claim 14 wherein the indicator element indicates true acceleration in the YZ plane at any inclination of the suspended mass in the YZ plane.

16. The inclinometer according to claim 12 wherein the Z axis that is within the orthogonal YZ and XZ planes is plumb.

17. A pendulous accelerometer translating a pendulous acceleration of a mass in first plane into an indication of this acceleration, which indication is in a second plane orthogonal to the first plane, the accelerometer comprising:

a mass suspended for pendulous movement in a first plane;

a member, connected to the mass, defining an extended region which is capable of tightly interlocking a wire and which undergoes movement in the first plane corresponding to the movement of the pendulous mass;

an angled wire in three dimensions and not in any one plane, which wire has and is supported for an axis of rotation wherein the axis is within the first plane, which wire tightly interlocks the member'"'"'s extended region so that the movement of the member'"'"'s region causes a rotation of the wire about its axis of rotation;

an indicator connected to the wire so that rotation of the wire causes deflection of the indicator in a second plane orthogonal to the first plane;

the member and the angled wire interlocking so that the tangent of an angular movement of the pendulous mass in an arc responsive to acceleration, causing a movement in the first plane of the member, results in a linear angular rotation of the wire, and a linear angular deflection of the indicator connected thereto.

18. The accelerometer according to claim 17 wherein the member comprises:

a substantially linear extension arm extending in a one direction about a pivot axis from the mass which is suspended for pendulous movement about the pivot axis in another direction, and presenting the region which is capable of interlocking a wire at its terminus region.

19. The accelerometer according to claim 17 wherein the arm'"'"'s terminus region is in the shape of a fork, which fork interlocks the wire between its tines.

20. The accelerometer according to claim 17 wherein the arm'"'"'s terminus region is in the shape of an aperture defined by the arm, which aperture interlocks the wire which passes therethrough.

21. A combination inclinometer and accelerometer, comprising:

a frame supporting a first Y axis shaft, a second Y axis shaft, and an X axis shaft;

a first pendulous mass angularly pivoting in the YZ plane about the X axis shaft causing rotation of this X axis shaft, the amount of angular pivoting being the vector sum of a component in the YZ plane of a gravitational vector and a component in the YZ plane of an acceleration vector both acting upon this first pendulous mass;

a second pendulous mass pivoting in the XZ plane about the second Y axis shaft causing rotation of this second Y axis shaft, the amount of angular pivoting being the vector sum of a component in the XZ plane of the gravitational vector and a component in the XZ plane of an acceleration vector both acting upon this second pendulous mass;

a first member affixed to and a extending esentially radially from the X axis shaft until presenting and defining, at a separation from the X axis shaft, a region that is capable of mechanically interlocking an element that passes through the region;

a second, helical, member affixed to and extending from the Y axis shaft until presenting and defining, at a substantially uniform separation from the Y axis shaft, a portion of a helix substantially axially centered about the Y axis shaft, this helical portion passing through and interlocking the region of the first member so that the tangent of the angle of rotation of the X axis shaft is translated into corresponding rotation of the first Y axis shaft;

wherein the component in the XZ plane of the gravitational vector, or inclination in the XZ plane, plus acceleration in the XZ plane are combinatorially resultant in rotation of the second Y axis shaft that is linear with the XZ plane inclination gravitational vector and acceleration; and

wherein the component in the YZ plane of the gravitational vector, or inclination in the YZ plane, plus acceleration in the YZ plane are combinatorially resultant in rotation of the first Y axis shaft that is linear with the YZ plane inclination gravitational vector and acceleration.

22. The combination inclinometer and accelerometer according to claim 21 further comprising:

a first indicator in an XZ plane affixed to the first Y axis shaft for indicating the rotation of the first Y axis shaft; and

a second indicator in the XZ plane affixed to the second Y axis shaft for indicating the rotation of the second Y axis shaft.

23. A method performed in an inclinometer/accelerometer of linearly indicating in single plane the combined gravitational and acceleration vector at and along each of two mutually orthongonal planes of the inclinometer/accelerometer, one of which planes is the plane of the indicating and the other of which planes is orthogonal to the plane of the indicating, the method of linearly indicating the combined gravitational and acceleration vector in an inclinometer/accelerometer comprising:

suspending a first pendulous mass for pivoting about an X axis shaft in a YZ plane, orthogonal to the XZ plane of the indicating, in response to the combined gravitational and acceleration vector in this YZ plane;

mechanically linearly translating in a kinematic mechanically space mechanism the arcuate motion of the first pendulous mass, which motion is in the YZ plane, into a rotational motion in the YZ plane, the translation transpiring by means of a first member affixed to the X axis shaft and extending therefrom that interlocks at its end region extended from the X axis shaft a second, helical, member that is connected to a Y axis shaft in the YZ plane and that extends therefrom so that, by the interlocking, the tangent of an angle of arcuate motion of the first pendulous mass lateraly couples an associated angular rotation of the Y axis shaft;

first coupling this rotational motoin of the Y-axis shaft in the YZ plane of the indicating to produce an indicating in the XZ plane of the first pendulous mass motion;

suspending a second pendulous mass for pivoting in a plane parallel to or coincident with the XZ plane of the indicating respectively to the combined gravitational and acceleration vector in this plane of the pivoting;

second coupling the motion of the second pendulous mass, which motion is in the plane parallel to, or coincident with the XZ plane of the indicating, to produce in the XZ plane an indication of this second pendulous mass motion;

wherein the indication of the first mass motion, and the indication of the second mass motion, are both within the XZ plane of the indicating, although each indication is representative of a combined gravitational acceleration vector which is within a plane orthogonal to the plane of the other;

wherein gravitation/acceleration occurring in each of two orthogonal YZ and XZ planes is indicated in one XZ plane.