[go: up one dir, main page]

GB2172995A - Monitoring the position of a member - Google Patents

Monitoring the position of a member Download PDF

Info

Publication number
GB2172995A
GB2172995A GB08508401A GB8508401A GB2172995A GB 2172995 A GB2172995 A GB 2172995A GB 08508401 A GB08508401 A GB 08508401A GB 8508401 A GB8508401 A GB 8508401A GB 2172995 A GB2172995 A GB 2172995A
Authority
GB
United Kingdom
Prior art keywords
cylinder
piston
pulse
mould
radiation
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Withdrawn
Application number
GB08508401A
Other versions
GB8508401D0 (en
Inventor
Steven Gustav Merz
Rene Keller
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.)
Emhart Industries Inc
Original Assignee
Emhart Industries Inc
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
Application filed by Emhart Industries Inc filed Critical Emhart Industries Inc
Priority to GB08508401A priority Critical patent/GB2172995A/en
Publication of GB8508401D0 publication Critical patent/GB8508401D0/en
Publication of GB2172995A publication Critical patent/GB2172995A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88Radar or analogous systems specially adapted for specific applications
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20Other details, e.g. assembly with regulating devices
    • F15B15/28Means for indicating the position, e.g. end of stroke
    • F15B15/2815Position sensing, i.e. means for continuous measurement of position, e.g. LVDT
    • F15B15/2869Position sensing, i.e. means for continuous measurement of position, e.g. LVDT using electromagnetic radiation, e.g. radar or microwaves
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88Sonar systems specially adapted for specific applications

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Electromagnetism (AREA)
  • Acoustics & Sound (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)

Abstract

The position of a member which is moved by the action of a piston and cylinder assembly (10, 12) is monitored using radiation pulse emitting and receiving means (36). A pulse of a radiation which will pass through the fluid in the cylinder of the assembly is transmitted into the interior of the cylinder (10) from an end portion of the cylinder so that the pulse travels along the cylinder to the piston (12) and is reflected thereby. The reflected pulse is detected and the elapsed time between the transmission and detection of the pulse is calculated. This gives the position of the piston from the elapsed time thereby enabling the position of the member to be obtained. The pulses are ultrasonic, laser or radio. Application to glassware forming machines is described. <IMAGE>

Description

SPECIFICATION Monitoring the position of a member This invention is concerned with monitoring the position of a member which is connected to a piston rod of the piston of a piston and cylinder assembly so that the member is moved when the piston is moved along cylinder by the introduction of fluid under pressure into the cylinder.
In many machines, it is desirable to able to monitor the position of a member to as certain whether the machine is operating as desired. One method of monitoring the position of a member is to provide a proximity detector which detects when the member reaches a particular position. However, this method is not applicable in all circumstances, for example where the member is moving in an environment which is hostile to proximity detectors or where the member is not reaching exactly the same position in each of its movements. Another method of monitoring the position of a member is to attach a linear potentiometer thereto so that the output of the linear potentiometer gives a continuous indication of the position of the member.However, the problem of hostile environments also arises in this method and there are many circumstances when there is insufficient space for the insertion of a linear potentiometer. In some circumstances, it is possible to monitor the position of a member optically or by using other radiation, the radiation either being reflected from the member when the member arrives in a certain position or being interrupted by the arrival of the member in a certain position. However, such methods are not possible when the member co-operates with other members which substantially surround it.
It is an object of the present invention, to provide a method of monitoring the position of a member which is connected to a piston rod of the piston of a piston and cylinder assembly so that the member is moved when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder wherein the position of the member can be monitored at any selected point in its movement and the detecting means used is protected from any hostile environment.
The invention provides a method of monitoring the position of a member which is connected to a piston rod of the piston of a piston and cylinder assembly so that the member is moved when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder, the method comprising transmitting one or more pulses of a radiation which passes through the fluid in the cylinder into the interior of the cylinder from an end portion thereof so that each pulse travels along the cylinder and is reflected by the piston, detecting each reflected pulse when it returns to said end portion of the cylinder, determining the elapsed time between the transmission of each pulse and the detection of the reflection thereof, and utilising the elapsed time to determine the position of the piston and hence of the member.
In a method in accordance with the last preceding paragraph, the position of the member can be monitored at any selected point in its movement by selecting the time at which the pulse is transmitted. Furthermore, the radiation pulse emitting and receiving means can be readily located in a position remote from any hostile environment in the vicinity of the member and occupies no space in the vicinity of the member. For example, the radiation pulse emitting and receiving means can be mounted in a recess in an end cap of the cylinder so that it is protected from any hostile environment by the cylinder.Alternatively, the radiation pulse emitting and receiving means can be mounted on a support on which an end cap of the cylinder is removably supported, a passage through the end cap allowing pulses from the radiation pulse emitting and receiving means to enter the cylinder and reflected pulses to reach said means, a seal preventing egress of fluid from the cylinder through the passage. In this case, the radiation pulse emitting and receiving means is protected from hostile environments by the support and the cylinder in combination. In this case, the piston and cylinder assembly can be removed from the support and replaced by an alternative piston and cylinder assembly without changing the radiation pulse emitting and receiving means and without disturbing electrical connections thereto.
Where it is desired to determine whether the member reaches a desired rest position thereof, a series of pulses may be transmitted, the elapsed times of successive pulses compared and the position of the member determined when a predetermined number of successive elapsed times are substantially constant.
Alternatively, a pulse may be transmitted at a time when the member should be in its rest position, and the elapsed time of that pulse is compared with a time representing the elapsed time expected if the member is in its desired rest position.
The invention is applicable to a method of monitoring the position of a parison-forming plunger of a glassware forming machine. Such plungers are moved into a mould cavity containing a gob of molten glass and press the gob to the shape of the cavity thereby forming a parison of molten glass which is subsequently blow into the shape of a glassware container. The plunger is moved into the cavity by the action of a piston and cylinder assembly until it is stopped by pressure from the molten glass so that the plunger does not always move to exactly the same position in the mould, the position depending on the exact amount of molten glass in the mould. It is particularly desirable to be able to monitor the maximum penetration depth of the plunger into the mould since this can be used to determine the quantity of glass which has been inserted into the mould cavity.This information can be used to determine whether the glassware should be rejected because it has either too little or too much glass in it and also to adjust gob forming means of a machine so that the next subsequent gob has a more correct quantity of glass.
The invention is also applicable, to a method of monitoring the position of a mould portion of a glassware forming machine which is connected to a piston rod of the piston and cylinder assembly so that the mould portion is moved, when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder, between a mouidopen position thereof in which moulded glass can be removed from the mould and a mouldclosed position thereof in which the mould portion co-operates with one or more further mould portions to define a cavity in which molten glass can be moulded. In this case, it is desirable to be able to determine whether the mould portion has reached its mouldclosed position at a desired time so that correct moulding can take place.For example, in the event that moulded glass is not removed from the mould as it should be, in the next operation of the machine, the mould portion may be unable to reach its mould-closed position and serious damage to the machine may result unless this condition is rapidly detected.
The mould-closed position of the mould portion may vary with wear and, when in its mould-closed position, is in contact with molten glass.
The invention also provides an apparatus for use in monitoring the position of a member which is connected to a piston rod of a piston-and-cylinder assembly so that the member is moved when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder, the apparatus comprising radiation transmitting and detecting means operative to transmit one or more pulses of a radiation which passes through the fluid in the cylinder into the interior of the cylinder from an end portion thereof so that each pulse travels along the cylinder and is reflected by the piston, and to detect each reflected pulse when it returns to said end portion of the cylinder, and time measuring means operative to determine the elapsed time between the transmission of each pulse and the detection of the reflection thereof and to produce an output signal whose magnitude depends on said elapsed time and indicates the position of the piston and hence of the member.
The invention is applicable to pneumaticallyoperating piston and cylinder assemblies and also to hydraulically-operating piston and cylinder assemblies so long as a suitable radiation is selected in each case. The pulse may be of an ultrasonic radiation, of laser light, or of an electromagnetic radiation in the radio wave band. The calculation steps mentioned above can suitably be carried out by electronic means and the results may be compared with pre-set standards or with the results obtained in previous operations.
The radiation pulse emitting and receiving means may comprise a transmitter and a detector mounted adjacent one another or alternatively, in some circumstances, a transceiver which can be switched between a transmitting mode and a detecting mode.
There now follows a detailed description, to be read with reference to the accompanying drawing, of a method of monitoring the position of a member and of an apparatus for use in the method which are illustrative of the invention. It is to be understood that the illustrative method and apparatus have been selected for description by way of example and not of limitation of the invention.
In the drawings: Figure 1 is a vertical cross-sectional view taken through a piston and cylinder assembly to which the illustrative method is applied; and Figure 2 is a diagrammatic view of the circuitry of the illustrative apparatus.
The piston and cylinder assembly shown in Figure 1 comprises a cylinder 10 and a piston 12 which is movable along the cylinder 10 by the introduction of air under pressure into the cylinder 10 through ports (not shown). The cylinder 10 is formed in a block of metal 14 which provides the cylindrical side wall of the cylinder 10 and a lower end cap 16 thereof.
An upper end cap 18 of the cylinder 10 is secured to the block 14 by bolts (not shown).
A tubular piston rod 20 extends upwardly from the piston 12 through a cylindrical passage 22 in the upper end cap 18, there being a seal to prevent the egress of air through the passage 22.
The piston and cylinder-assembly 10, 12 is for use in moving a parison-forming plunger of a glassware forming machine (not shown) into a mould (not shown) containing a gob of molten glass. The plunger is mounted on the piston rod 20 of the piston 12 so that the plunger is moved into the mould when the piston 12 is moved along the cylinder 10 by the introduction of air under pressure into the cylinder beneath the piston 12.
The lower end cap 16 of the cylinder 10 is secured by bolts (not shown) which can readily be removed to a support 26 which forms part of the frame of the glassware forming machine. Thus, the end cap 16 is removably secured to the support 26 so that the piston and cylinder assembly 10, 12 can readily be removed from the support and replaced by a similar piston and cylinder assembly. A tube 28 extends through the centre of the cylinder 10 axially thereof and enters a passage 30 through the lower end cap 16, and connects with a passage 32 in the support 26, there being a seal 33 to prevent egress of air from the cylinder 10 through the passage 30. The tube 28 passes centrally through the piston 12 in a passage (not shown) therein and enters the interior of the tubular piston rod 20.
The tube 28 is to enable an air supply to be connected to the interior of the plunger through the tubular piston rod 20, the tube 28 and the passage 32 or, alternatively, a vacuum source to be connected to the interior of the mould through the passage 32, the tube 28, and the piston rod 20.
An ultrasonic radiation pulse emitting and receiving means 36 is mounted on the support 26 in alignment with a passage 38 which passes through the end cap 16 and enters the interior of the cylinder 10. The ultrasonic radiation pulse emitting and receiving means is a piezoxyde ultrasonic disk manufactured by the Phillips Company under designation PXE 5.
This can be energised to emit an ultrasonic pulse and can also act as a detector for ultrasonic pulses, since it produces an electrical output on receipt of an ultrasonic pulse.
In the illustrative method, the position of the parison-forming plunger is monitored to determine the depth of penetration of the plunger into the mould. The illustrative method comprises using the ultrasonic radiation pulse emitting and receiving means 36 to transmit an ultrasonic pulse through the passage 38 into the interior of the cylinder 10. The pulse, therefore, is transmitted from an end portion of the cylinder 10 so that it travels along the cylinder to the piston 12 and is reflected by the piston. The ultrasonic radiation pulse emitting and receiving means 36 is then used to detect the pulse after it has been reflected by the piston 12. The pulse returns to the emitting and receiving means 36 through the passage 38 after reflection by the piston 12.
In the illustrative method, a series of pulses is transmitted, the elapsed times of successive pulses is compared, and the position of the member is determined when a predetermined number of successive elapsed times are substantially constant. In a modification of the illustrative method, however, one pulse may be transmitted at a time when the plunger should have reached its maximum penetration into the mould and the penetration calculated from the elapsed time.
The illustrative method also comprises calculating the elapsed time between the transmission of the pulse and the detection of the reflected pulse. This calculation is carried out by electronic means (see Figure 2) to which the emitting and receiving means 36 is connected by wires 44. Since the speed of sound waves in the air in the cylinder 10 is known (any necessary corrections for the pressure of the air in the cylinder 10 and the temperature thereof having been made), the position of the piston from the elapsed time can simply be calculated thereby obtaining the depth of penetration of the plunger into the mould. The depth obtained can then be compared with a pre-set standard or with previous results or with an average of previous results over a period of time.
Figure 2 illustrates diagrammatically the use of the invention on a glassware manufacturing machine of the individual section type operating in the single gob mode in which each section manufactures one article at a time.
Figure 2 shows the pistons 1 2a to 1 2f of the six piston and cylinder assemblies for moving the parison-forming plungers of the machine and the six radiation emitting and receiving means 36a to 36f associated therewith.
Each emitting and receiving means 36a to 36f is connected to an oscillator 50 arranged to energise them all. The oscillator 50 is connected to a sequencer 52 which is operable to switch on the oscillator 50 at predetermined times to cause it to energise the emitting and receiving means 36a to 36f so that they all emit a pulse which is reflected back by the associated piston 1 2a to 12f.
The emitting and receiving means 36a to 36f are connected via capacitors to respective inputs 54a to 54f of an analog switch 54.
The analog switch 54 is also connected to the sequencer 52 and has an output connected via an amplifier 56 to a multiplexer 58. When the analog switch 54 receives an impulse from the sequencer 52, it connects a different one of its inputs 54a to 54f to its output, the arrangement being such that the inputs 54a to 54f are connected in turn to the output. The sequencer 52 is also connected to the multiplexer 58 and to a further multiplexer 60 which is also connected to the line connecting the oscillator 50 to the emitting and receiving means 36a to 36f.
The multiplexers 58 and 60 and also the sequencer 52 are also connected to a time measuring device 62 arranged to measure the time interval between the receipt of a signal from the multiplexer 60 and of a signal from the multiplexer 58 and to produce an output indicating this interval.
In operation, when it is desired to monitor the position of a first of the pistons 12a, the sequencer 52 produces a signal which causes the oscillator 50 to produce a pulse, causes the analog switch 54 to connect its input 54a to its output and re-sets the multiplexers 58 and 60 and the timing device 62. The pulse produced by the oscillator 50 causes the emitting and receiving means 36a to 36f to each produce a pulse of ultrasonic radiation each of which travels through its respective cylinder and is reflected from its respective piston 1 2a to 1 2f back to its respective emitting and receiving means 36a to 36f. The pulse produced by the oscillator 50 also causes the multiplexer 60 to pass a signal S1 to the time measuring device 62.The signal S1 represents the time at which the ultrasonic pulses are emitted.
When each ultrasonic pulse returns to its respective emitting and receiving means 36a to 36f after being reflected from its respective piston 1 2a to 12f, the emitting and receiving means passes a signal to the associated input 54a to 54f of the analog switch 54. The signals received by the analog switch 54 on the inputs 54b to 54f have no effect but that received on the input 54a is passed to the multiplexer 58 which passes a signal S2 to the time measuring device 62. The signal S2 represents the time at which the ultrasonic pulse is received and the device 62 measures the time T between the signals SI and S2 which indicates the position of the piston 12a.
The next signal produced by the sequencer 52 causes the above-described method to be repeated but for the input 54b and the position of the piston 12b to be indicated. Subsequent signals of the sequencer 52 cause the positions of the pistons 12c, 12d, 1 2e and 1 2f to be indicated and then the sequence is repeated. Thus, the position of each piston 12a to 12f is indicated in turn and, by causing the sequencer 52 to produce signals at a sufficiently high frequency, the positions of the pistons are monitored by a single circuit.
The position of each piston 1 2a to 1 2f is monitored at intervals (at every sixth signal of the sequencer 52) so that a series of ultrasonic pulses are transmitted along each cylinder. The successive times T of each piston 12a to 12f are compared and when a predetermined number of successive times T are compared the position of the piston is determined giving the maximum penetration of the plunger.

Claims (12)

1. A method of monitoring the position of a member which is connected to a piston rod of the piston of a piston-and-cylinder assembly so that the member is moved when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder, the method comprising transmitting one or more pulses of a radiation which passes through the fluid in the cylinder into the interior of the cylinder from an end portion thereof so that each pulse travels along the cylinder and is reflected by the piston, detecting each reflected pulse when it returns to said end portion of the cylinder, determining the elapsed time between the transmission of each pulse and the detection of the reflection thereof, and utilising the elapsed time to determine the position of the piston and hence of the member.
2. A method according to claim 1 of determining whether the member reaches a desired rest position thereof wherein a series of pulses is transmitted, the elapsed times of successive pulses are compared, and the position of the member is determined when a predetermined number of successive elapsed times are subssantially constant.
3. A method according to claim 1 of determining whether the member reaches a desired rest position thereof, wherein a pulse is transmitted at a time when the member should be in its rest position, and the elapsed time of that pulse is compared with a time representing the elapsed time expected if the member is in its desired rest position.
4. A method according to any one of claims 1 to 3, wherein the member is a parisonforming plunger of a glassware forming machine movable into a mould containing molten glass by the action of a piston-and-cylinder assembly.
5. A method according to any one of claims 1 to 3, wherein the member is a mould portion of a mould of a glassware forming machine movable by the action of a piston-andcylinder assembly between a mould-open position thereof in which moulded glass can be removed from the mould and a mould-closed position thereof in which the mould portion co-operates with one or more further mould portions to define a cavity in which molten glass can be moulded.
6. A method according to any one of the preceding claims, wherein the pulse is of an ultrasonic radiation.
7. A method according to any one of claims 1 to 5, wherein the pulse is of laser light.
8. A method according to any one of claims 1 to 5, wherein the pulse is of an electromagnetic radiation in the radio wave band.
9. A method of monitoring the position of a member which is connected to a piston rod of the piston of a piston-and-cylinder assembly so that the member is moved when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder substantially as hereinbefore described with reference to the accompanying drawing.
10. Apparatus for use in monitoring the position of a member which is connected to a piston rod of piston-and-cylinder assembly so that the member is moved when the piston is moved along the cylinder by the introduction of fluid under pressure into the cylinder, the apparatus comprising radiation transmitting and detecting means operative to transmit one or more pulses of a radiation which passes through the fluid in the cylinder into the interior of the cylinder from an end portion thereof so that each pulse travels along the cylinder and is reflected by the piston, and to detect each reflected pulse when it returns to said end portion of the cylinder, and time measuring means operative to determine the elapsed time between the transmission of each pulse and the detection of the reflection thereof and to produce an output signal whose magnitude depends on said elapsed time and indicates the position of the piston and hence of the member.
11. Apparatus according to claim 10, wherein the radiation transmitting and detecting means comprises a piezoxyde ultrasonic disk mounted in a recess in an end cap of the cylinder, and an oscillator connected to the disc and operative to energise the disc so that it transmits ultrasonic pulses.
12. Apparatus for use in monitoring the po sition of a member substantially as hereinbe fore described with reference to the accom panying drawings.
GB08508401A 1985-03-30 1985-03-30 Monitoring the position of a member Withdrawn GB2172995A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08508401A GB2172995A (en) 1985-03-30 1985-03-30 Monitoring the position of a member

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08508401A GB2172995A (en) 1985-03-30 1985-03-30 Monitoring the position of a member

Publications (2)

Publication Number Publication Date
GB8508401D0 GB8508401D0 (en) 1985-05-09
GB2172995A true GB2172995A (en) 1986-10-01

Family

ID=10576989

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08508401A Withdrawn GB2172995A (en) 1985-03-30 1985-03-30 Monitoring the position of a member

Country Status (1)

Country Link
GB (1) GB2172995A (en)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0644329A1 (en) * 1993-09-18 1995-03-22 Adam Opel Ag Fuel injection nozzle for internal combustion engines
WO1998023867A1 (en) * 1996-11-27 1998-06-04 Case Corporation Method and apparatus for sensing piston position
US5901633A (en) * 1996-11-27 1999-05-11 Case Corporation Method and apparatus for sensing piston position using a dipstick assembly
EP0921091A3 (en) * 1997-12-05 1999-06-16 Grove U.S. LLC Smart tele-cylinder
US5977778A (en) * 1996-11-27 1999-11-02 Case Corporation Method and apparatus for sensing piston position
US6005395A (en) * 1997-11-12 1999-12-21 Case Corporation Method and apparatus for sensing piston position
US6142059A (en) * 1996-11-27 2000-11-07 Case Corporation Method and apparatus for sensing the orientation of a mechanical actuator
EP1139117A1 (en) * 2000-03-14 2001-10-04 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Device and method for detecting position of movable body by using ultrasonic waves
US6588313B2 (en) 2001-05-16 2003-07-08 Rosemont Inc. Hydraulic piston position sensor
US6722260B1 (en) 2002-12-11 2004-04-20 Rosemount Inc. Hydraulic piston position sensor
US6722261B1 (en) 2002-12-11 2004-04-20 Rosemount Inc. Hydraulic piston position sensor signal processing
US6725731B2 (en) 2000-03-08 2004-04-27 Rosemount Inc. Bi-directional differential pressure flow sensor
US6789458B2 (en) 2000-03-08 2004-09-14 Rosemount Inc. System for controlling hydraulic actuator
US6817252B2 (en) 2000-03-08 2004-11-16 Rosemount Inc. Piston position measuring device
US6848323B2 (en) 2000-03-08 2005-02-01 Rosemount Inc. Hydraulic actuator piston measurement apparatus and method
EP1522431A3 (en) * 2003-10-08 2005-10-05 Hitachi, Ltd. Suspension device for vehicle
ITBO20090588A1 (en) * 2009-09-16 2011-03-17 A M A S P A OPERATING MACHINE
DE102023127901A1 (en) * 2023-10-12 2025-04-17 Vega Grieshaber Kg Base cover for a pneumatic cylinder or hydraulic cylinder

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1525720A (en) * 1975-12-20 1978-09-20 Univ Cardiff Distance measuring apparatus
GB1561700A (en) * 1976-05-20 1980-02-27 Sack Gmbh Measuringapparatus for measuring the roll gap in gauge-controlled roll stands
GB2043250A (en) * 1979-02-23 1980-10-01 Davy Loewy Ltd Ultrasonic transducer arrangement for indicating position of a piston
GB1602006A (en) * 1978-05-23 1981-11-04 Univ Cardiff Ultrasonic distance measuring in apparatus having relatively movable parts

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1525720A (en) * 1975-12-20 1978-09-20 Univ Cardiff Distance measuring apparatus
GB1561700A (en) * 1976-05-20 1980-02-27 Sack Gmbh Measuringapparatus for measuring the roll gap in gauge-controlled roll stands
GB1602006A (en) * 1978-05-23 1981-11-04 Univ Cardiff Ultrasonic distance measuring in apparatus having relatively movable parts
GB2043250A (en) * 1979-02-23 1980-10-01 Davy Loewy Ltd Ultrasonic transducer arrangement for indicating position of a piston

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
WO A1 83/03478 *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0644329A1 (en) * 1993-09-18 1995-03-22 Adam Opel Ag Fuel injection nozzle for internal combustion engines
WO1998023867A1 (en) * 1996-11-27 1998-06-04 Case Corporation Method and apparatus for sensing piston position
US5901633A (en) * 1996-11-27 1999-05-11 Case Corporation Method and apparatus for sensing piston position using a dipstick assembly
US5977778A (en) * 1996-11-27 1999-11-02 Case Corporation Method and apparatus for sensing piston position
US6142059A (en) * 1996-11-27 2000-11-07 Case Corporation Method and apparatus for sensing the orientation of a mechanical actuator
US6005395A (en) * 1997-11-12 1999-12-21 Case Corporation Method and apparatus for sensing piston position
EP0921091A3 (en) * 1997-12-05 1999-06-16 Grove U.S. LLC Smart tele-cylinder
US6725731B2 (en) 2000-03-08 2004-04-27 Rosemount Inc. Bi-directional differential pressure flow sensor
US6789458B2 (en) 2000-03-08 2004-09-14 Rosemount Inc. System for controlling hydraulic actuator
US6817252B2 (en) 2000-03-08 2004-11-16 Rosemount Inc. Piston position measuring device
US6848323B2 (en) 2000-03-08 2005-02-01 Rosemount Inc. Hydraulic actuator piston measurement apparatus and method
US6490227B2 (en) 2000-03-14 2002-12-03 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Device and method for detecting position of movable body by using ultrasonic waves
EP1139117A1 (en) * 2000-03-14 2001-10-04 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Device and method for detecting position of movable body by using ultrasonic waves
US6588313B2 (en) 2001-05-16 2003-07-08 Rosemont Inc. Hydraulic piston position sensor
US6722260B1 (en) 2002-12-11 2004-04-20 Rosemount Inc. Hydraulic piston position sensor
US6722261B1 (en) 2002-12-11 2004-04-20 Rosemount Inc. Hydraulic piston position sensor signal processing
EP1522431A3 (en) * 2003-10-08 2005-10-05 Hitachi, Ltd. Suspension device for vehicle
ITBO20090588A1 (en) * 2009-09-16 2011-03-17 A M A S P A OPERATING MACHINE
DE102023127901A1 (en) * 2023-10-12 2025-04-17 Vega Grieshaber Kg Base cover for a pneumatic cylinder or hydraulic cylinder

Also Published As

Publication number Publication date
GB8508401D0 (en) 1985-05-09

Similar Documents

Publication Publication Date Title
GB2172995A (en) Monitoring the position of a member
US4252176A (en) Injection ram control
US4675043A (en) Apparatus for manufacture of tubular elements for ink jet printers
NL8004390A (en) METHOD AND APPARATUS FOR NON-DESTRUCTIVE TESTING OF CEMENT.
US6311803B1 (en) Acoustical position detector
CZ200038A3 (en) Process and apparatus for measuring wall thickness of hot hollow glass products
US3827287A (en) Methods of and apparatus for measuring the thickness of successive sections of a cable jacket
KR930702657A (en) Ultrasonic apparatus and method for measuring the outer diameter of tubes
US4711120A (en) Method of wear monitoring using ultrasonic phase comparison
US5867274A (en) System for the measurement of the cut length of moving articles
US4517152A (en) Method of testing fuel element tubes for defects
GB2164933A (en) A method of monitoring the positions of two movable side portions of a mould of a glassware forming machine
US11927583B2 (en) Measuring device and method for a contactless analysis of a food product in a production line
KR900004209B1 (en) Hollow Glass Container Inspection System
EP0075997A2 (en) Well logging device
JP2854256B2 (en) Apparatus for discontinuously detecting the thickness of a layer above a metal melt
US4582522A (en) Method of monitoring the movement of a member in a glassware forming machine of the individual section type
US3608352A (en) Ultrasonic transducers
US4604122A (en) Method of sensing gobs of molten glass
GB2157831A (en) Magnetically monitoring the movement of a rod
JPS5814297B2 (en) Mold filling confirmation device
CA2187957C (en) Ultrasonic sensors for on-line monitoring of castings and molding processes at elevated temperatures
CA1134147A (en) Hot gob detector for a glassware forming machine
SU1786458A1 (en) Acoustical profiler of underground wells filled with water
SU896525A1 (en) Radiometric flaw detector

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)