WO1994015174A1

WO1994015174A1 - Angle indicating device

Info

Publication number: WO1994015174A1
Application number: PCT/GB1993/002605
Authority: WO
Inventors: Clive Stanley Richards
Original assignee: Clive Stanley Richards
Priority date: 1992-12-24
Filing date: 1993-12-20
Publication date: 1994-07-07
Also published as: GB9512450D0; GB9227004D0; AU5707994A; GB2288877B; GB2288877A

Abstract

An angle indicating device comprises a pendulum (5) pivotal relative to a datum surface (4) and a transducer (9) arranged to produce an electrical output signal in response to and dependent on the pivotal angular orientation of the pendulum relative to the datum surface. Typically, the datum surface is provided on the exterior of a housing, with the pendulum and transducer being mounted internally of the housing. An analogue to digital converter (10) is preferably provided to convert the analogue electrical output signal from the transducer to a digital signal suitable for use with an LCD display (12).

Description

Angle Indicating Device

The present invention relates to an angle indicating device such as a' spirit level, inclinometer or the like.

According to the invention, there is provided an angle indicating device comprising

(a) a datum surface;

(b) pendulum means pivotal relative to said datum surface; and

(c) transducer means adapted to produce an electrical output signal in response to and dependent on the pivotal angular orientation of said pendulum means relative to said datum surface.

The pendulum means typically comprises a weighted arm free to pivotally rotate and align with the direction of action of the force of the earth's gravity.

It is preferred that the electrical output signal produced by the transducer means is substantially directly proportioned to the pivotal angular orientation of the pendulum means relative to the datum surface.

Typically, the transducer means is arranged to produce an output voltage dependent on the relative angular orientation of the pendulum means and the datum surface.

It is preferred that the output voltage from the transducer means is arranged to give a visual indication of the angular orientation of the datum surface relative to the horizontal or vertical. Advantageously, display means is provided giving a readable visual indication of the angular orientation of the datum surface relative to the horizontal or vertical. In one embodiment the visual indication may be produced by analogue means for example where the transducer output voltage is connected to a galvanometer type indicator.

In a preferred embodiment the transducer output signal is processed to give a digital visual indication of the angular orientation of the datum surface relative to the horizontal or vertical. Typically, in this embodiment the display means will comprise a liquid crystal display (LCD). In this embodiment it is preferred that an analogue to digital convenor is provided to produce a digital signal from the analogue output signal of the transducer. Appropriate signal conditioning apparatus, such as a microprocessor or the like may also be provided advantageously to perform algorithmic functions on the output signal. It is preferred that the device is provided with one or more display function actuators, selectively actuable to modify the output displayed at the display means.

Typically, the transducer means is of a rotary type having first and second transducer elements which rotate relative to one another with the transducer output signal being dependent on the degree of relative rotation between the two. Typically, the transducer means is of a resistive type.

Advantageously, the pendulum means is rigidly connected to a rotatable transducer element such that pivotal angular movement of the pendulum means causes corresponding angular rotary movement of the respective transducer element.

It is preferred that the pendulum means, and transducer means are provided in a unitary housing with advantageously the datum surface comprising an outer surface of the housing.

The invention will now be further described in a specific embodiment, by way of example only, and with reference to the accompanying drawings; in which

Figure 1 is a schematic view of components comprising an angle indicating device according to the invention;

Figure 2 is a schematic explanatory view of an angle indicating device according to the invention; and

Figure 3 is an exemplary perspective view of an angle indicating device according to the invention in use.

Referring to the drawings, there is shown an angle indicating device, generally designated 1 for measuring the angular orientation of a slope 2 inclined at an angle and relative to the horizontal. The angle indicating device 1 comprises a box-like housing 3 having one side or surface 4 provided as a datum surface which in use lies in contact with the slope 2 the angular orientation of which is being measured.

Referring to Figure 1 in particular, in the interior of housing 3 there is mounted a pendulum 5 comprising a weight 7 and arm 6 which is rigidly connected to limb 8, and via limb 8 to a first element 9a of a rotary transducer 9. Pendulum 5 is pivotal on an axis along limb 8 such that as the angular orientation of the datum surface 4 changes, the pendulum pivots due to the action of gravity. As the angular orientation of the pendulum 5 changes relative to the datum surface 4 of the housing, a rotary element of transducer 9 rotates in unison therewith about its axis relative to a fixed element of transducer 9.

The fixed and rotary elements of transducer 9 typically comprise a resistive transducer (such as a rotary potentiometer) which produces an output voltage dependent on the relative orientation of the fixed and rotary elements. As the respective orientation of the fixed and rotary elements of transducer 9 change due to rotation of the rotary transducer element, the output voltage from transducer 9 changes proportionately.

Alternatively, a rotary capacative transducer may be used to produce the output signal; in which case the transducer 9 will typically be provided as a port of an a.c. tuned oscillating circuit (not shown). The output signal from the transducer 9 is passed via appropriate circuitry to an analogue to digital converter 10 and signal processor 11 (such as a microprocessor) which is calibrated to give a readable angular digital output display at the LCD display screen 12. Typically, the microprocessor performs a suitable algorithm to convert the angle being measured to the required angle jS of the datum surface 4 relative to the horizontal.

It should be appreciated that as an alternative to using a resistive or capacative rotary transducer (or other analogue rotary transducer) in conjunction with an analogue to digital convenor, a direct digital angular measurement transducer may be used such as for example an opto-electronic reading sytem using a rotatable binary-coded encoder disc.

Referring to Figure 3, the device 1 is shown with the datum surface 4 of the housing 3 resting on a course of brickwork 16. Function buttons 13, 14, 15 are provided on the housing and actuable to modify the output displayed at the LCD display screen 12. Typically the function buttons are actuable to perform one or more of the following functions.

1. To fix the display showing a recorded angle such that angles on relatively inaccessible surfaces may be measured and the recorded angle read when the device has been removed from the surface. The display may then be cleared by pressing the corresponding function button for a second time.

2. To reset the display to 0° on a first inclined surface such that the angle of a second inclined surface can conveniently be measured relative thereto.

Claims

CLAIMS:

1. An angle indicating device comprising,

(a) a datum surface;

(b) pendulum means pivotal relative to said datum surface; and

2. An angle indicating device according to claim 1 , wherein the electrical output signal produced by the transducer means is substantially proportional to the pivotal angular orientation of the pendulum means relative to the datum surface.

3. An angle indicating device according to claim 1 or claim 2, wherein the transducer means is arranged to produce an output voltage dependent on the relative angular orientation of the pendulum means and the datum surface.

4. An angle indicating device according to claim 3, wherein the output voltage from the transducer means is arranged to produce a visual indication of the angular orientation of the datum surface relative to the horizontal or vertical.

5. An angle indicating device according to any preceding claim further comprising display means arranged to give a readable visual indication of the angular orientation of the datum surface relative to the horizontal or vertical.

6. An angle indicating device according to claim 5 wherein the display means comprises a digital display.

7. An angle indicating device according to claim 6, wherein the digital display comprises a display of LCD type.

8. An angle indicating device according to claim 6 or claim 7 which further comprises an analogue to digital converter arranged to produce a digital signal from thee analogue output signal of the transducer means.

9. An angle indicating device according to any preceding claim further comprising signal conditioning apparatus arranged to condition the output signal from the transducer means.

10. An angle indicating device according to claim 5, further comprising one or more display function actuators, selectively actuable to modify the output displayed at the display means.

11. An angle indicating device according to any preceding claim, wherein the transducer means is of a resistive type.

12. An angle indicating device according to any preceding claim wherein the transducer means comprises a rotary type transducer having first and second transducer elements which rotate relative to one another, the transducer output signal being dependent on the degree of relative rotation between the two.

13. An angle indicating device according to claim 12, wherein the pendulum means is rigidly connected to a rotatable transducer element such that pivotal angular movement of the pendulum means causes corresponding angular rotary movement of the respective transducer element.

14. An angle indicating device according to any preceding claim, wherein the pendulum means, and transducer means are provided in a unitary housing, the datum surface comprising an outer surface of the housing.

15. An angle indicating device substantially as herein described, with reference to the accompanying drawings.