GB2189616A

GB2189616A - Engineer's protractor

Info

Publication number: GB2189616A
Application number: GB08603188A
Authority: GB
Inventors: Colin Leonard Talbot
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-02-10
Filing date: 1986-02-10
Publication date: 1987-10-28
Also published as: GB8603188D0

Abstract

Digital engineers protractor to measure angles of machine tools and give a value of these angles comprises an analog transmitter (1) to measure the positional movement of the protractor. A signal from the transmitter (1) is picked up by a receiver (2) and angles are measured off by an adjustable sliding rule against the side of the protractor (3), a digital display (10) is provided. <IMAGE>

Description

SPECIFICATION Engineer's protractor TECHNICAL FIELD This invention relates to an engineer's protractor.

BACKGROUND Engineer's protractor's come in a combination of types from bevel protractors to combination sets all of which are used for measuring angles.

However, these protractors are not very acurate and are very difficult to read because the scale has to be etched so fine.

ESSENTIAL TECHNICAL FEATURES PREVIOUS PROTRACTOR According to the present inventions it enables angles to be measured with a fine adjustment on the better makes, a specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings. This is also a mechanical device. I have designed a way in which angles can be measured and can be transferred into a digital readout.

Figure 1 shows in perspective the digital engineer's protractor detailing the components.

Fig. 1, No 1:- Analogue transmitter Fig. 1, No 2:- Emf transmitter and analog receiver.

Fig. 1, No 3:- Slide-rule.

Fig. 1, No 6:- Spring-ring and seal.

Fig. 1, No 7:- Locking-screw.

Fig. 1, No 8:- Fine adjustment screw.

Fig. 1, No 10:- Digital display Figure 2 shows a side view of the protractor.

Fig. 2, No 1:- Analogue transmitter Fig. 2, No 2:- Emf transmitter and analog receiver Fig. 2, No 4:- Circular base Fig. 2, No 9:- Top (Lid) Figure 3 shows an end view of the head of the protractor Fig. 3, No 3:- Slide-rule-arm.

Fig. 3, No 4:- Circular base Fig. 3, No 5:- Rollers Figure 4 shows a detailed drawing of the analog transmitter Fig. 4, No 1:- Spiral resister Fig. 4, No 2:- Insulator Fig. 4, No 3:- Conductor Fig. 4, No 4:- Centre locating whole.

Fig. 4, No 5:- Whole insulator Fig. 4, No 6:- Analog receiver head Fig. 4, No 7:- Analog calibrator Figure 5 shows a side view of the analog transmitter Fig. 5, No 1:- Analog resister Fig. 5, No 2:- Insulators Fig. 5, No 3:- Conductor Fig. 5, No 4:- Emf-in head Fig. 5, No 5:- Analog signal receiver head Figure 6 a diagram of the electronic circuit Fig. 6, No 1:- Analog transmitter Fig. 6, No 2:- Analog to digital converter Fig. 6, No 4:- Eprom Fig. 6, No 5:- Counters Fig. 6, No 7:- Display Figure 7 micrometer and depth MIC showing analog transmitter (POT) Fig. 7, No 1:- Analog transmitter Fig. 7, No 2:- Emf transmitter and analog receiver Fig. 7, No 3:- Analog transmitter Fig. 7, No 4:- Emf transmitter and analog receiver Figure 8 Viernier showing analog transmitter Fig. 8, No 1:- Analog transmitter Fig. 8, No 2:- Emf transmitter and analog receiver.

Referring to the drawings the digital protractor comprises of an analog transmitter set in the head of the protractor this analog transmitter pivots at its centre. (Fig. 1, No: 1). The signal is then picked up by the receiver. (Fig. 1, No: 2). The angles are measured off by the adjustable sliding-rule against the side of the protractor (Fig. 1, No: 3). The slide-ruie and analog transmitter are fixed to a circular base (Fig. 2, No: 4). This is all then fixed onto rollers (Fig. 3, No: 5. In the head there is a spring-ring and seal connecting to the slide-rule (Fig. 1, No: 6).

(Fig. 1, No: 7) Locking-screw This locks onto the spring-ring and seal which serves the purpose of locking the slide-rule and analog transmitter to a fixed angle setting.

(Fig. 1, No: 8) Fine adjustment screw This works off the spring-ring and seal to give very fine adjustment to the slide-rule and analog transmitter (Fig. 2, No: 9) Top of the electronic's compartment (Fig. 4, No: 2) Insulator Insulator to a given size to which a calculated error of rotation can be measured in the resistance.

Figure 9 shows a 360 analogue transmitter Fig. 9, No: 1- Analogue calibrator Fig. 9, No: 2- Analogue calibrator housing Fig. 9, No: 3- Emf in for calibrator ANALOGUE TRANSMITTER When new, the contact point will be very fine,

contact point and contact point and accumulative resistance Xl L1 2 =C.S.A.

Resistance=C.S.A. (cross-sectional area) For example X1,X2,h,1, will all be different values at any given point. Ohms law will then give different values of resistance.

Being that this works to ohms law it is possible to put this information into then eprom and calculate exact position.

If a known position is given e.g. 0 degrees, when new C.S.A. is known, the resistance is known therefore contact wear can also be calculated.

when new when worn

When worn the contact area at 0 degrees will be greater, and there the centre will be calculated, and exact position known.

AUTO CALIBRATION 0-180 degrees and 0-360 degrees 1) When new R1=resistance to ratio of X resistance.

2) When worn R2=resistance+wear=drop in R also resistance of X will drop 3) Distance at 0 degrees will be; R1-R2=W 4) So therefore being ratio of R1 to R2 to be constant no matter what position then wear and position can be calculated.

5) This will mean that if both waveforms are inputed to a eprom, exact position can be calculated at all times.

NOTE: R2 will not wear because this is a static component.

e.g. d=DISTANCE

Claims

1. Analog transmitter will give an analog signal from a minimum resistance to a maximum resistance then to minimum, in a 360 degree cycle. (see Fig. 4 and 5)

2. This analog transmitter can be used for rotary or uncoiled for linear functions to give an analog signal in any device, wether this be micrometer, depth mic, vierniers, or any other design of protractor, the signal can be converted to incremental or absolute values of measurement

3. This analog transmitter is a absolute positional device in a three dimensional plane, and can distinguish left to right, the application of the principle can be put in a magnetical, optical, voltage form.

4. The protractor can measure angles from the information resieved from the analog transmitter. This information is converted into a digital output then to a display.

5. This analog transmitter can triangulate error. Plus Claims 3 the position of the emitters are important to the fact to give a pyramid effect. Plus Claims 2

6. The digital engineers protractor is designed to measure angles of machine tools. Plus Claim 4.