GB2445797A

GB2445797A - Scale rule with digital display

Info

Publication number: GB2445797A
Application number: GB0701025A
Authority: GB
Inventors: Michael Cross
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-01-19
Filing date: 2007-01-19
Publication date: 2008-07-23
Also published as: GB0701025D0

Abstract

A longitudinal measuring device which reads absolute linear distances on constructional drawings, blueprints and the like and then by utilising pre-selected scales will display digitally the scale distance. The instrument is capable of being preset with a known scale distance and thereafter will proportion measured distances and provide comparative scale distances displayed digitally in millimetres. A measuring circuit and digital readout 3 is mounted on a sliding element 1 which moves parallel to the fixed linear scale 6 and is connected either electrically or magnetically to the main body of the instrument thus allowing the sliding body displaced distance travelled to be accurately monitored. The microprocessor then converts the absolute distance by the nominated scale with the result being displayed digitally on the slider.

Description

Digitally displayed Measuring device Descrintion The invention is

primarily but not exclusively to be used in the construction industry for measuring paper drawings which are not printed at the draughtsman's intended scaleable size. Most drawings can be scaled at Al or A0 however, for ease of use are printed and worked on at A3 or even A4. This presents problems when dimensions are required to be taken from that drawing. The operator of this device is able to enter a known scale distance into the measuring device which then calculates the scale and displays all subsequent measured distances in millimetres at that scale.

Distances can also be taken similarly utilising the pre-programmed standard scales such as 1:1, 1:50, 1:100, 1:250 etc or simply visually at 1:1 utilising the printed linear scale on the front edge of the instrument all as would be measured using a standard absolute ruler.

The device is a longitudinal rule with a sliding element (1), a measuring distance marker (2), a digital display (3), a manual entry keypad (4), a preset scale entry pad (5), a 1:1 linear printed scale in millimetres (6), and a fine adjustment wheel (7). The instrument can either be powered by battery or a solar panel can be included to the upper body. The instrument is activated by a on! off button within the keypad (10).

The instrument should be reset to zero prior to any measurements being undertaken.

This is simply achieved by sliding the moving element (1) as far to the left as possible thus the sliding body is filly closed and the distance marker (2) set to zero on the printed linear scale and then the reset button (8) is pushed. The instrument will now read at 1:1 scale and display in millimetres the distance between zero on the printed scale and the set position of marker on the sliding element (2).

To take scale readings the instrument should be reset as described above and then a pre-programmed scale selected from the standard range on the scale entry pad (5).

The absolute distance between zero and the position of the marker on the sliding element will then be electronically converted and digitally displayed to scale as selected.

To enable the operator to take scale readings of a drawing with unknown scale the instrument is reset as previously described and then the data entry button (9) is pressed. The zero on the printed scale is then set to line with one end of a known distance on the drawing and the sliding body marker (2) moved until it is in line with the opposing end of the known distance. The millimetre scale distance is then entered via the data entry keypad and the data entry button (9) again pressed. The instrument is now set and any subsequent distance readings taken will be calculated as a direct proportion of that entered known distance and displayed digitally in millimetres to that calculated scale. The instrument can be used repeatedly at that scale until the instrument is reset or switched off.

Areas of rectangles and circles can also be calculated by selecting the correct area function. By measuring the diameter of the circle or the two sides of the rectangle will provide the area at the selected scale.

The instrument calculates distance travelled by an array of capacitance position sensors-these conductors spaced on the main body and slider form a row of capacitors bridging the gap between slider and scale (ii). The measured capacities yield the displacement. These are cleaned as the slider is moved through the introduction of a wiper to the underside of the slider.

Claims

Claims 1. That the instrument is a distance measurement rule capable of

measuring absolute distances and following the manual entry of the scale distance of that measurement the device then calculates the distance of subsequent measurements relative to that scale distance.
2. That the instrument is a distance measuremejn rule capable of measuring absolute distances and calculating the scale distance from one selected from the keypad standard scales.
3. That all distances and areas will be displayed digitally on the instrument readout display.
4. That the instrument can measure as a manual rule to a 1 1 scale utilising a printed scale to the front of the fixed body.
5. That the instrument can measure to a 1:1 scale utilising the moving marker and digital display.
6. That the instrument will calculate areas of rectangles in the required scale.
7. That the instrument will calculate areas of circles in the required scale.