GB2372571A

GB2372571A - Pressure gauge with means for adjusting for temperature

Info

Publication number: GB2372571A
Application number: GB0104620A
Authority: GB
Inventors: Dimitrios Myzithras
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-02-23
Filing date: 2001-02-23
Publication date: 2002-08-28
Also published as: GB0104620D0

Abstract

A pressure gauge calculator can be a mechanical (Fig. 1) or an electronic variant (Fig.2). Both variants utilise a thermometer (1, Fig.1), (14, Fig.2), (31, Fig.3) to obtain the temperature. The mechanical variant includes a rotating crown (2, Fig. 1) or any movable temperature scale on the pressure-gauge dial (32, Fig. 3) , of any shape. An indicator (5, Fig.1), (35, Fig.3) is attached, processed or painted on the dial and is also allowed to rotate with the movement of the temperature scale (2,32). The electronic variant includes electronics, circuitry/microprocessors, that are used to identify the pressure and temperature and perform calculations, as well as a numerical pad (10) for data input and control. The gauge-calculator may include connections .(6, Fig.1), (6, Fig.2) to the air-pump as well as those to the object, whose fluid properties are to be obtained.

Description

PRESSURE CALCULATOR-GAUGE This invention relates to a pressure gauge, such as those found in petrol stations and car-accessories shops. Apart from reading the pressure of the tyre, it can actually perform calculations by reading the temperature of the air inside the tyre, by means of either a mechanical or electronic calculator. It could also be applied for other fluids and purposes in research laboratories and elsewhere.

Tyre pressure gauges are very common mostly the mechanical type, but also the electronic. However, the main disadvantage is that once the tyre covers the distance of approximately a mile, the temperature of the air inside the tyre increases due to friction and from basic physics, so is the pressure. Hence, it is difficult to estimate if the tyre has a deficiency or surplus of air (especially after a long journey), since the manufacturer suggests optimum pressures for static conditions and usually at around 15 C (ambient temperature).

The objective of this invention is not only to estimate what the'hot'tyre pressure would be at'ambient-static'conditions, but also to'project'the required pressure at 'static'to the equivalent one for the actual air-temperature. This is to allow the user to make accurate correction of the pressure.

Essentially, the calculator-gauge operates as a common tyre-pressure gauge. This means that it includes all those components that make the reading of the pressure an accurate task. All the tubes and internal parts remain the same. However, a thermometer of any type (mechanical, pneumatic, electric, electronic, etc. ) can be used to provide the accurate reading of the temperature. Preferably, it will be of the electronic digital type. FIGURE 1 shows the front view of the mechanical type of the calculator-gauge. FIGURE 2 shows the possible layout of an electronic derivative. FIGURE 3 shows a derivative of the mechanical type with linear shape. For the mechanical type apart from the thermometer (1, Fig. l, 31, Fig. 3) there is the added element of a rotating circular scale (crown) (2, Fig. l), or a linear scale (32, Fig. 3) located anywhere around, on top, inside or on the side of the dial of the pressure gauge (3, Fig. l, 33, Fig. 3). A crown is considered first only due to the simplicity of a circular design. A linear scale for linear pressure gauges can also be applied and any other shapes that can perform the task of this concept are acceptable.

The scale may be calibrated in degrees Centigrade or any other units of Temperature (degrees Fahrenheit, Rankine, Kelvin, etc. ), which are attached, painted or processed on the crown 2 or scale 32. The range of the units on the crown/scale and the varying spacing is based on the properties of the inflating fluid. For inflating fluids other than air (for motorsport or research purposes, etc. ), other crowns/scales will have to be introduced. Hence, the design must allow interchangeability. Finally, both sides of the crown 2/scale 32 can be printed/processed (etched, notched, etc. ) and the appropriate side can be selected accordingly.

Since the range of a degree Centigrade equals that of a Kelvin both scales can be displayed on the same side of the crown for simplicity. Different colours can be applied to different temperature scales to avoid confusion.

Once the pressure and temperature readings are obtained, the user rotates the crown 2 to align the needle 4 of the pressure gauge with the same temperature reading that is suggested by the thermometer (e. g. 20 C). In the design of Fig. 3 this would be done by translating the linear scale 32 to align the number 20 to the needle 34 Then the user reads the pressure, which corresponds to the temperature suggested by the car/tyre manufacturer (e. g. 15OC). This is done with the help of a bright coloured'thread'or other indicator 5 attached, painted or processed inside, around or on top of the dial 3,

which is allowed to rotate with the rotation of the crown 2 (Fig. 1). Again in Fig. 3 this indicator is component 35. If the desired pressure is lower (to the left of thread) or higher (to the right of thread) than the actual one, the user deflates or inflates the tyre respectively, until the pressures'match'. With the electronic type (Fig. 2), apart from reading the pressure, the entire calculation process can be processed by means of electronic equipment (circuitry, microprocessors, etc. ). Values can be manually introduced, by means of an arithmetic dial (10, Fig. 2). The'static'pressure suggested by the manufacturer will be manually introduced in position 11 and the'static'temperature in position 13. The actual pressure is depicted in position 12 and the air-temperature reading is obtained from the thermometer and automatically introduced to the calculator in position 14. The layout as described above and as depicted by Figure 2 is only one possible layout of the display. The calculator-gauge encompasses any possible layout that can perform the operation required. With suitable controls the tyre can be inflated or deflated until the system automatically stops the pump. Hence, apart from reading and calculating, the electronic type can also be used as the control for the mechanical air pump.

However, the electronic type can also be used with a manual control for the air pump. By providing indication as to if the pressure is high or low, for example with different coloured lights or arrows or indeed any other indication the user can be advised to inflate or deflate, until the calculator gauge indicates that the tyre is properly inflated.

Claims

CLAIMS 1. A pressure gauge fitted with a thermometer and a temperature scale for the mechanical type and electronic circuitry and a numerical pad for the electronic one.
2. A pressure gauge as claimed in Claim 1 where the temperature scale is allowed to move or rotate according to its shape and the shape of the pressure gauge dial.
3. A pressure gauge as claimed in Claim 1 where the numerical pad is used to input data into the electronic circuitry/processor.
4. A pressure gauge as claimed in any preceding claim where the gauge may have connections/tubing/inlet and outlet and can be either connected to an air or other fluid pump or operate isolated to perform calculations.
5. A pressure gauge as claimed in any preceding claim which is made from metal, non-metal, plastics material or wood and the derivatives of wood, or from a combination of these materials.
6. A pressure gauge substantially as herein described and illustrated in the accompanying drawings.