GB2367408A - Imperial to metric conversion of a rotary mechanical indicator - Google Patents
Imperial to metric conversion of a rotary mechanical indicator Download PDFInfo
- Publication number
- GB2367408A GB2367408A GB0020745A GB0020745A GB2367408A GB 2367408 A GB2367408 A GB 2367408A GB 0020745 A GB0020745 A GB 0020745A GB 0020745 A GB0020745 A GB 0020745A GB 2367408 A GB2367408 A GB 2367408A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rotary mechanical
- wheel
- gear
- mechanical index
- imperial
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 6
- 239000000463 material Substances 0.000 claims description 5
- 239000004033 plastic Substances 0.000 claims description 4
- 229920003023 plastic Polymers 0.000 claims description 4
- 239000011354 acetal resin Substances 0.000 claims description 2
- 229920005669 high impact polystyrene Polymers 0.000 claims description 2
- 239000004797 high-impact polystyrene Substances 0.000 claims description 2
- 229920006324 polyoxymethylene Polymers 0.000 claims description 2
- DHKHKXVYLBGOIT-UHFFFAOYSA-N 1,1-Diethoxyethane Chemical compound CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 claims 1
- 239000012530 fluid Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F15/00—Details of, or accessories for, apparatus of groups G01F1/00 - G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus
- G01F15/06—Indicating or recording devices
- G01F15/065—Indicating or recording devices with transmission devices, e.g. mechanical
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D4/00—Tariff metering apparatus
- G01D4/02—Details
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Measuring Volume Flow (AREA)
Abstract
Apparatus for imperial to metric conversion of a rotary mechanical indicator 210 for such as a gas meter display comprises a shaft 29 and gear-pair 28a and 29a interposed between drum drive wheel 20 and output gear 25, the ratio of gear 28a to gear 29a is selected so that the display 210 indicates in metric units.
Description
IMPERIAL TO METRIC CONVERTER FOR A
ROTARY MECHANICAL INDEX
This invention relates to rotary mechanical indexes such as those commonly used to display gas consumption on a gas meter. In particular, the invention relates to apparatus for the conversion of an existing meter index calibrated for providing a reading in imperial units to recalibrate the index to provide a reading in metric units.
Rotary mechanical index apparatus are well known. Generally, such indexes comprise a plurality of display wheels rotatably mounted on a common shaft and each having the digits 0 to 9 printed sequentially around their periphery. Each display wheel is provided with gear teeth which are driven by an adjacent drive wheel, the drive wheel for any given display wheel is driven by a single tooth on an adjacent display wheel. As the first display wheel completes a 360 degree rotation, the single tooth engages with the drive wheel for the adjacent display wheel, the drive wheel has teeth which engage with the gear teeth of the corresponding display wheel and thereby causes rotation of the display wheel through approximately 36 degrees such that the digit displayed to the front of the display wheel is increased by 1. The first of the display wheels is driven by a separate drive wheel which is driven by whatever is being consumed and measured by the meter. Such index apparatus are commonly used in domestic and industrial gas meters.
Gas meters in the UK have for many years registered in units of cubic feet, recent changes in European weights and measures legislation requires that all new meters read in metric units (i. e. cubic metres). It will be understood that existing imperial meters which are recovered from the field for whatever reason must either be scrapped or somehow converted to read metric units. The calibration of these meters is generally made by use of a suitable gear arrangement which converts the rate of flow of the consumed fluid into a rotation of the display wheels to display a suitable measurement. This calibration involves gearing systems which may be primarily located within the container carrying the gas. It will be understood that it is not desirable to open such a container to modify the operation of a meter.
The present invention aims to provide an apparatus for the conversion of a gas meter reading imperial units to one which reads metric units which involves minimal
interference with, and minimal redesign of, the existing meter. 7
In accordance with the present invention there is provided apparatus for the imperial to metric conversion of a rotary mechanical index comprising : a drum drive wheel engageable with a first display wheel of the rotary mechanical index and rotatably mounted about a first end of a drum drive spindle, the drum drive spindle carrying at its second end a pinion, the pinion engaging with a gear wheel which is rotatably mounted at a first end of a gear wheel spindle, the second end of the gear wheel spindle being engageable with the pointer drive gear of the rotary mechanical index, the ratio of the pinion to the gear wheel being selected to provide an appropriate increase or reduction in the speed of rotation of the first display wheel so as to provide a numerical display in metric units rather than in imperial units.
Where the meter is an imperial reading gas meter, it has been found that a pinion to gear wheel ratio of 12: 34 provides a suitable conversion factor to metric units.
Preferably the component parts of the meter converter apparatus are made from a hard, durable plastics material. Examples of suitable materials include acetal resins and high impact polystyrene.
In another aspect the present invention provides a rotary mechanical index incorporating an apparatus as previously described.
In a third aspect the present invention provides a gas meter comprising a rotary mechanical index incorporating an apparatus as previously described.
The invention will now be further described by way of exemplification with reference to the following drawings in which:
Figure 1 shows schematically a prior art imperial rotary mechanical index for a domestic gas meter.
Figure 2 shows schematically the prior art imperial rotary mechanical index of figure 1 incorporating a converter apparatus of the present invention.
Figure 3 shows the apparatus of Figure 2 in an exploded view.
As can be seen from Figure 1, a prior art imperial index drive comprises a display unit 10 comprising a plurality of display wheels rotatably mounted on a common shaft. Adjacent the terminal display wheel is a spindle 7 carrying a drum drive wheel 7a. The drum drive wheel 7a interlockably engages with teeth provided around the periphery of the terminal display wheel facing the spindle 7. A pointer drive gear 5 is carried by the spindle 7. The pointer drive gear 5 engages with a change gear 4 which in turn engages with drive gear 3 carried by the meter output drive shaft and meter drive dog 1,2 of the meter. The spindle 7, drum drive wheel 7a, pointer drive gear 5 and change gear 4 are mounted in the index frame 6 of the display apparatus.
In Figure 2 components which are essentially the same as those shown in the prior art apparatus of Figure 1 are given the same reference numeral with the prefix 2.
As can be seen from Figure 2, the converter apparatus of the invention is positioned between the first display wheel of the display unit 210 and the pointer drive gear 25.
The converter apparatus consists of a spindle 28 carrying a 34 tooth gear wheel 28a.
The spindle 28 also acts as support for the pointer drive gear 25. Gear wheel 28a engages with a 12 tooth pinion 29a carried by drum drive spindle 29. Also mounted on the drum drive spindle 29 is the drum drive wheel 20. It will be appreciated that the incorporation of the gear pair 28a, 29a provides an appropriate conversion factor between cubic feet and cubic metres. The gear pair rotates in an opposite direction to the drive wheel 7a in Figure 1, thus the drive wheel 20 of the converter apparatus is positioned at the opposite end of the drum drive spindle 29 so that rotation of the drive wheel brings about forward motion of the display wheel 210a.
It will be understood that the foregoing represents just one embodiment of the invention and is not intended to be restrictive of the true scope of the invention as claimed in the appended claims.
Claims (9)
- CLAIMS 1. Apparatus for the imperial to metric conversion of a rotary mechanical index comprising : a drum drive wheel engageable with a first display wheel of the rotary mechanical index and rotatably mounted about a first end of a drum drive spindle, the drum drive spindle carrying at its second end a pinion, the pinion engaging with a gear wheel which is rotatably mounted at a first end of a gear wheel spindle, the second end of the gear wheel spindle being engageable with the pointer drive gear of the rotary mechanical index, the ratio of the pinion to the gear wheel being selected to provide an appropriate increase or reduction in the speed of rotation of the first display wheel so as to provide a numerical display in metric units rather than in imperial units.
- 2. Apparatus as claimed in claim 1 wherein the rotary mechanical index is for a gas meter and the ratio between the pinion and gear wheel is 12: 34.
- 3. Apparatus as claimed in claim 1 or claim 2 comprising substantially of plastics material.
- 4. Apparatus as claimed in claim 3 wherein the plastics material is an acetal resin.
- 5. Apparatus as claimed in claim 3 wherein the plastics material is high impact polystyrene.
- 6. A rotary mechanical index incorporating an apparatus as claimed in any preceding claim.
- 7. A gas meter comprising a rotary mechanical index as claimed in claim 5.
- 8. Apparatus substantially as described herein with reference to Figures 2 and 3.
- 9. A converted gas meter substantially as described herein with reference to Figures 2 and 3.9. A rotary mechanical index substantially as described herein with reference to Figures 2 and 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0020745A GB2367408A (en) | 2000-08-23 | 2000-08-23 | Imperial to metric conversion of a rotary mechanical indicator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0020745A GB2367408A (en) | 2000-08-23 | 2000-08-23 | Imperial to metric conversion of a rotary mechanical indicator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0020745D0 GB0020745D0 (en) | 2000-10-11 |
| GB2367408A true GB2367408A (en) | 2002-04-03 |
Family
ID=9898129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0020745A Withdrawn GB2367408A (en) | 2000-08-23 | 2000-08-23 | Imperial to metric conversion of a rotary mechanical indicator |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2367408A (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB641789A (en) * | 1946-11-20 | 1950-08-23 | Victoria Machine Tool Company | Improvements in or relating to gearing for affording conversion to and from british and metric measure |
| US3696776A (en) * | 1969-01-30 | 1972-10-10 | Gamet Products Ltd | Dial assemblies |
| GB1354964A (en) * | 1970-06-08 | 1974-06-05 | Potgieter A P | Speedometer and or milometer converters |
| US3952693A (en) * | 1974-08-20 | 1976-04-27 | Hardinge Brothers, Inc. | Machine tool dial assembly |
| US4200985A (en) * | 1978-01-18 | 1980-05-06 | Primus Mfg., Inc. | Visual indicator for alternate units of measure |
| US4284028A (en) * | 1979-02-14 | 1981-08-18 | Swanburg Mark G | English/metric conversion mechanism for speedometers |
| US4365195A (en) * | 1979-12-27 | 1982-12-21 | Communications Satellite Corporation | Coplanar waveguide mounting structure and test fixture for microwave integrated circuits |
| US5081868A (en) * | 1989-09-27 | 1992-01-21 | Bombardier, Inc. | Speedometer conversion |
-
2000
- 2000-08-23 GB GB0020745A patent/GB2367408A/en not_active Withdrawn
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB641789A (en) * | 1946-11-20 | 1950-08-23 | Victoria Machine Tool Company | Improvements in or relating to gearing for affording conversion to and from british and metric measure |
| US3696776A (en) * | 1969-01-30 | 1972-10-10 | Gamet Products Ltd | Dial assemblies |
| GB1354964A (en) * | 1970-06-08 | 1974-06-05 | Potgieter A P | Speedometer and or milometer converters |
| US3952693A (en) * | 1974-08-20 | 1976-04-27 | Hardinge Brothers, Inc. | Machine tool dial assembly |
| US4200985A (en) * | 1978-01-18 | 1980-05-06 | Primus Mfg., Inc. | Visual indicator for alternate units of measure |
| US4284028A (en) * | 1979-02-14 | 1981-08-18 | Swanburg Mark G | English/metric conversion mechanism for speedometers |
| US4365195A (en) * | 1979-12-27 | 1982-12-21 | Communications Satellite Corporation | Coplanar waveguide mounting structure and test fixture for microwave integrated circuits |
| US5081868A (en) * | 1989-09-27 | 1992-01-21 | Bombardier, Inc. | Speedometer conversion |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0020745D0 (en) | 2000-10-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |