GB2137350A - Set-point indicating instruments - Google Patents

Set-point indicating instruments Download PDF

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Publication number
GB2137350A
GB2137350A GB08403770A GB8403770A GB2137350A GB 2137350 A GB2137350 A GB 2137350A GB 08403770 A GB08403770 A GB 08403770A GB 8403770 A GB8403770 A GB 8403770A GB 2137350 A GB2137350 A GB 2137350A
Authority
GB
United Kingdom
Prior art keywords
dial
arm
ofthe
pointer
measuring apparatus
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.)
Granted
Application number
GB08403770A
Other versions
GB2137350B (en
GB8403770D0 (en
Inventor
James Charles Lefever
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOC Group Ltd
Original Assignee
BOC Group Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from GB838308757A external-priority patent/GB8308757D0/en
Application filed by BOC Group Ltd filed Critical BOC Group Ltd
Priority to GB08403770A priority Critical patent/GB2137350B/en
Publication of GB8403770D0 publication Critical patent/GB8403770D0/en
Publication of GB2137350A publication Critical patent/GB2137350A/en
Application granted granted Critical
Publication of GB2137350B publication Critical patent/GB2137350B/en
Expired legal-status Critical Current

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Classifications

    • 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
    • G01D13/00—Component parts of indicators for measuring arrangements not specially adapted for a specific variable
    • G01D13/22—Pointers, e.g. settable pointer
    • G01D13/26—Pointers, e.g. settable pointer adapted to perform a further operation, e.g. making electrical contact
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P1/00—Details of instruments
    • G01P1/07—Indicating devices, e.g. for remote indication
    • G01P1/08—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers
    • G01P1/10—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers for indicating predetermined speeds
    • G01P1/11—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers for indicating predetermined speeds by the detection of the position of the indicator needle

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

A measuring apparatus in the form of a pressure gauge 1 includes a pointer 2 movable over a dial 3. An adjustable set point 8 forms part of an arm 7 which can move around the dial 3 and carry with it a plastics housing 15 in which are mounted an infra-red emitting diode 16 and a silicon photodarlington transistor 17. The pointer 2 has an end portion 9 which reflects the infra-red radiation from the diode 16 to the transistor 17 when the pointer 2 is in alignment with the set point 8. The set point 8 is movable around the dial by means of a friction roller 10 which engages the periphery of an annular disc 6 attached to the arm 7. <IMAGE>

Description

SPECIFICATION Improvements in measuring apparatus The present invention relates to measuring appar atus forsetting a selected value and displaying an actual value of a parameter and in particulartoa pressure gauge with an adjustable set point.
Measuring apparatus in the form of a speedometer is known from UK Patent No. 1449776. The speedometer is circular and includes a dial overtheface of which moves a pointer for indicating the actual speed of a vehicle to which the speedometer is connected. A set point arm or needle is mounted above the dial face for movement around a central pivot. The set point arm carries a detection head including a light emitter and two photo-electric receivers. The arrangement is such thatwhen the pointer moves between the dial face and the detection head, light emanating from the emitter is reflected back to the receivers, thereby triggering off a warning device to indicate when a set speed has been reached.This measuring apparatus suffers from the disadvantage that the set point arm together with the detection head is mounted above the face ofthe dial and thereby obscures the dial.
Another speedometer is known from UK Patent No.
1206597 in which a set point device includes a body in which are embedded the ends of a pair of optical cables. The body is positioned aboutthe periphery of the dial to be aligned with a preselected speed, for example 30 mph. When a pointer reaches the 30 mph mark on the dial, a reflector carried by a pointer reflects light emitted from the end of one cable towards the end ofthe other cable which produces a warning effect.
This measuring apparatus relies on a light source spaced from the apparatus and not forming part ofthe apparatus. The use of lengths of optical cable causes the apparatus to be bulky and is conducive to faults in the transmission ofthe light.
It is an aim ofthe present invention to provide a measuring apparatus having a set point arrangement which avoids the necessity of a bulky mechanical/ electrical systems orthe obscuring oftheface ofthe dial ofthe appartus.
According to the present invention, a measuring apparatus comprises a pointer movable overthe face of a dial, an electro-magnetic radiation source and a sensorfordetecting electro-magnetic radiation emanating from said source, the source and the sensor both being mounted on an arm,which arm is mounted on the measuring apparatus for rotation around the periphery ofthe dial face without obscuring the dial face, at leastthe tip of the pointer having a material capable of reflecting the electro-magnetic radiation from the source to the sensor so that the position of the pointer can be sensed at any pre-selected position ofthe arm around the dial.
Preferably, the electro-magnetic radiation source is an infra-red emitting diode and the sensor is a silicon photodarlington transistor.
The diode and the transistor can be together in a plastics housing attached to the arm.
An embodiment ofthe invention will now be described, by way of example, reference being made to the Figures of the accompanying diagrammatic drawings in which Figure 1 is an exploded perspective view of a measuring apparatus in the form of a pressure gauge; Figure 2 is a plan view ofthe pressure gauge of Figure 1; Figure 3 is a vertical elevation ofthe pressure gauge of Figure 1; Figure 4 is a detail in perspective of part of an adjustable set point; and Figure 5 is a schematic plan of a further detail of the adjustable set point.
As shown, a measuring apparatus in the form of a pressure gauge 1 includes a pointer 2 movable over a dial 3 for indicating the pressure of a fluid when the pressure gauge 1 is in use. The pointer 2 has at one end, a portion 9 capable of reflecting infra-red radiation as will be explained.
An arm assembly 4 (see Figure 4) is clamped to the back of the pressure gauge between friction washers 5 and includes an annular disc 6from which extends an arm 7. The forward (as shown) end ofthe arm 7 is formed at right angles two the remainder of the arm and has the shape of a point 8 which, aswill be explained, can be lined up with indicia on the face ofthe dial 3.
Afriction roller 10 isspring loadedto engagethe periphery of the disc 6 and can be rotated by means of knob11.
Mounted on the arm 7 for movement therewith is a plastics housing 15. The housing 15 has embedded therein a source of electro-magnetic radiation in the form of an infra-red emitting diode 16 and a sensorfor electro-magnetic radiation in the form of a silicon photodarlington transistor 17.
In use, the knob 11 is rotated by an operator which in turn rotates the friction roller 10 and hence the disc 6 and arm 7. Rotation takes place until the point 8 is aligned with pre-selected indicia on the dial 3. The arm 7 carries with itthe housing 15 together with the diode 16 and transistor 17.
When the pressure of the fluid being measured is sufficient to cause the pointer 2 to align with the set point8theend portion9will reflectinfra-red light emitted from the diode backto the transistor 17.
Receipt of an infra-red signal bythe transistor 17 will operate a warning device which tells an operator that the pressure has reached a pre-determined set level.
Although references have been made to infra-red radiation, it will be appreciated that any other form of electro-magnetic radiation could be used. If other electro-magnetic radiation is used, then the end portion 9 would be made of a material or coated with a material to reflect that electro-magnetic radiation.
The particular advantage of the measuring appar atus described is that the diameter of the gauge 1 is not significantly increased bythevarious integers of the adjustable set point arrangement. Furthermore, the dial 3 of the gauge is unobstructed.
1. A measuring apparatus comprising a pointer movable overtheface of a dial, an electro-magnetic radiation source and a sensorfordetecting electromagnetic radiation emanating from said source, the source and the sensor both being mounted on an arm, which arm is mounted on the measuring apparatus for
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in measuring apparatus The present invention relates to measuring appar atus forsetting a selected value and displaying an actual value of a parameter and in particulartoa pressure gauge with an adjustable set point. Measuring apparatus in the form of a speedometer is known from UK Patent No. 1449776. The speedometer is circular and includes a dial overtheface of which moves a pointer for indicating the actual speed of a vehicle to which the speedometer is connected. A set point arm or needle is mounted above the dial face for movement around a central pivot. The set point arm carries a detection head including a light emitter and two photo-electric receivers. The arrangement is such thatwhen the pointer moves between the dial face and the detection head, light emanating from the emitter is reflected back to the receivers, thereby triggering off a warning device to indicate when a set speed has been reached.This measuring apparatus suffers from the disadvantage that the set point arm together with the detection head is mounted above the face ofthe dial and thereby obscures the dial. Another speedometer is known from UK Patent No. 1206597 in which a set point device includes a body in which are embedded the ends of a pair of optical cables. The body is positioned aboutthe periphery of the dial to be aligned with a preselected speed, for example 30 mph. When a pointer reaches the 30 mph mark on the dial, a reflector carried by a pointer reflects light emitted from the end of one cable towards the end ofthe other cable which produces a warning effect. This measuring apparatus relies on a light source spaced from the apparatus and not forming part ofthe apparatus. The use of lengths of optical cable causes the apparatus to be bulky and is conducive to faults in the transmission ofthe light. It is an aim ofthe present invention to provide a measuring apparatus having a set point arrangement which avoids the necessity of a bulky mechanical/ electrical systems orthe obscuring oftheface ofthe dial ofthe appartus. According to the present invention, a measuring apparatus comprises a pointer movable overthe face of a dial, an electro-magnetic radiation source and a sensorfordetecting electro-magnetic radiation emanating from said source, the source and the sensor both being mounted on an arm,which arm is mounted on the measuring apparatus for rotation around the periphery ofthe dial face without obscuring the dial face, at leastthe tip of the pointer having a material capable of reflecting the electro-magnetic radiation from the source to the sensor so that the position of the pointer can be sensed at any pre-selected position ofthe arm around the dial. Preferably, the electro-magnetic radiation source is an infra-red emitting diode and the sensor is a silicon photodarlington transistor. The diode and the transistor can be together in a plastics housing attached to the arm. An embodiment ofthe invention will now be described, by way of example, reference being made to the Figures of the accompanying diagrammatic drawings in which Figure 1 is an exploded perspective view of a measuring apparatus in the form of a pressure gauge; Figure 2 is a plan view ofthe pressure gauge of Figure 1; Figure 3 is a vertical elevation ofthe pressure gauge of Figure 1; Figure 4 is a detail in perspective of part of an adjustable set point; and Figure 5 is a schematic plan of a further detail of the adjustable set point. As shown, a measuring apparatus in the form of a pressure gauge 1 includes a pointer 2 movable over a dial 3 for indicating the pressure of a fluid when the pressure gauge 1 is in use. The pointer 2 has at one end, a portion 9 capable of reflecting infra-red radiation as will be explained. An arm assembly 4 (see Figure 4) is clamped to the back of the pressure gauge between friction washers 5 and includes an annular disc 6from which extends an arm 7. The forward (as shown) end ofthe arm 7 is formed at right angles two the remainder of the arm and has the shape of a point 8 which, aswill be explained, can be lined up with indicia on the face ofthe dial 3. Afriction roller 10 isspring loadedto engagethe periphery of the disc 6 and can be rotated by means of knob11. Mounted on the arm 7 for movement therewith is a plastics housing 15. The housing 15 has embedded therein a source of electro-magnetic radiation in the form of an infra-red emitting diode 16 and a sensorfor electro-magnetic radiation in the form of a silicon photodarlington transistor 17. In use, the knob 11 is rotated by an operator which in turn rotates the friction roller 10 and hence the disc 6 and arm 7. Rotation takes place until the point 8 is aligned with pre-selected indicia on the dial 3. The arm 7 carries with itthe housing 15 together with the diode 16 and transistor 17. When the pressure of the fluid being measured is sufficient to cause the pointer 2 to align with the set point8theend portion9will reflectinfra-red light emitted from the diode backto the transistor 17. Receipt of an infra-red signal bythe transistor 17 will operate a warning device which tells an operator that the pressure has reached a pre-determined set level. Although references have been made to infra-red radiation, it will be appreciated that any other form of electro-magnetic radiation could be used. If other electro-magnetic radiation is used, then the end portion 9 would be made of a material or coated with a material to reflect that electro-magnetic radiation. The particular advantage of the measuring appar atus described is that the diameter of the gauge 1 is not significantly increased bythevarious integers of the adjustable set point arrangement. Furthermore, the dial 3 of the gauge is unobstructed. CLAIMS
1. A measuring apparatus comprising a pointer movable overtheface of a dial, an electro-magnetic radiation source and a sensorfordetecting electromagnetic radiation emanating from said source, the source and the sensor both being mounted on an arm, which arm is mounted on the measuring apparatus for rotation around the periphery ofthe dial face without obscuring the dial face, at leastthetip ofthe pointer having a material capable of reflecting the electromagnetic radiation from the source to the sensor, so thatthe position of the pointer can be sensed at any pre-selected position ofthe arm around the dial.
2. A measuring apparatus as claimed in claim 1, in which the electro-magnetic radiation source is an infra-red emitting diode and the sensor is a silicon photodarlington transistor.
3. A measuring apparatus as claimed in claim 2, in which the diode and the transistor are mounted together in a plastics housing attached to said arm.
4. A measuring apparatus as claimed in claim 3, in which one end ofthe arm informed as a pointto act as a set point indicator and the opposite end is attached to a disc, the periphery ofwhich disc is engaged by the periphery of a rotatable friction rollerfor rotating the disc and thereby the arm around the dial.
5. A measuring apparatus constructed and arranged substantially as hereinbeforedescribed with reference to and as illustrated the Figures of the accompanying drawings.
GB08403770A 1983-03-30 1984-02-14 Set-point indicating instruments Expired GB2137350B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08403770A GB2137350B (en) 1983-03-30 1984-02-14 Set-point indicating instruments

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB838308757A GB8308757D0 (en) 1983-03-30 1983-03-30 Measuring apparatus
GB08403770A GB2137350B (en) 1983-03-30 1984-02-14 Set-point indicating instruments

Publications (3)

Publication Number Publication Date
GB8403770D0 GB8403770D0 (en) 1984-03-21
GB2137350A true GB2137350A (en) 1984-10-03
GB2137350B GB2137350B (en) 1986-06-18

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Family Applications (1)

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GB08403770A Expired GB2137350B (en) 1983-03-30 1984-02-14 Set-point indicating instruments

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1002830A (en) * 1962-10-29 1965-09-02 Stanley Sealey Instr Ltd Instrument supervision
GB1040636A (en) * 1963-11-01 1966-09-01 Dresser Ind Improvements in or relating to apparatus for an external pointer-adjustment to a dial instrument
GB1137648A (en) * 1965-08-11 1968-12-27 Emile Hugi Improvements in or relating to speedometers
GB1206597A (en) * 1967-04-24 1970-09-23 Lucas Industries Ltd Speed warning device
GB1437909A (en) * 1973-04-09 1976-06-03 Hauser Verwaltungs Gmbh Instrument for measurement and control of a measurable quantity
GB1445597A (en) * 1972-11-21 1976-08-11 Ko An Inc Speed responsive timing circuit
GB1471965A (en) * 1975-02-14 1977-04-27 Philllps F Warning device for use with an echo sounder speedometer or other measuring instrument

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1002830A (en) * 1962-10-29 1965-09-02 Stanley Sealey Instr Ltd Instrument supervision
GB1040636A (en) * 1963-11-01 1966-09-01 Dresser Ind Improvements in or relating to apparatus for an external pointer-adjustment to a dial instrument
GB1137648A (en) * 1965-08-11 1968-12-27 Emile Hugi Improvements in or relating to speedometers
GB1206597A (en) * 1967-04-24 1970-09-23 Lucas Industries Ltd Speed warning device
GB1445597A (en) * 1972-11-21 1976-08-11 Ko An Inc Speed responsive timing circuit
GB1437909A (en) * 1973-04-09 1976-06-03 Hauser Verwaltungs Gmbh Instrument for measurement and control of a measurable quantity
GB1471965A (en) * 1975-02-14 1977-04-27 Philllps F Warning device for use with an echo sounder speedometer or other measuring instrument

Also Published As

Publication number Publication date
GB2137350B (en) 1986-06-18
GB8403770D0 (en) 1984-03-21

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PCNP Patent ceased through non-payment of renewal fee