CA1224861A - Dispenser malfunction detector - Google Patents
Dispenser malfunction detectorInfo
- Publication number
- CA1224861A CA1224861A CA000448980A CA448980A CA1224861A CA 1224861 A CA1224861 A CA 1224861A CA 000448980 A CA000448980 A CA 000448980A CA 448980 A CA448980 A CA 448980A CA 1224861 A CA1224861 A CA 1224861A
- Authority
- CA
- Canada
- Prior art keywords
- pressure
- nozzle
- liquid
- valve
- signal
- 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.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
- B05B12/08—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
- B05B12/085—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means responsive to flow or pressure of liquid or other fluent material to be discharged
Landscapes
- Spray Control Apparatus (AREA)
- Control Of Fluid Pressure (AREA)
- Measuring Fluid Pressure (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
DISPENSER MALFUNCTION DETECTOR
ABSTRACT
A dispenser for fluid under pressure has a sensor affixed to it to sense the pressure of the fluid proximate the dispenser discharge opening to generate a pressure reflective signal. A comparator is connected to receive the pressure reflective signal to compare the pressure signal with a preselected band of pressure values which are selected to reflect operating pressure when the dispenser discharge opening is opened. The comparator generates a malfunction signal when the sensed pressure signal, is outside the preselected band.
ABSTRACT
A dispenser for fluid under pressure has a sensor affixed to it to sense the pressure of the fluid proximate the dispenser discharge opening to generate a pressure reflective signal. A comparator is connected to receive the pressure reflective signal to compare the pressure signal with a preselected band of pressure values which are selected to reflect operating pressure when the dispenser discharge opening is opened. The comparator generates a malfunction signal when the sensed pressure signal, is outside the preselected band.
Description
" 12248fi~ ~
DISPLNSrR MALFUNCTION DETECTOR
BACK~.ROIJ~D O~ Tl~ VF.I~TION
FI~'~LL) _F TIIE IMVFNTION:
This invention relates to monitoring devices and more particularly relates to monitoring devices used to detect malful-lctionillg fluid dispensers.
STATEr`lE.`~T OF ART:
~ ,, . . _ Typical fluid dispensing systems in one form include a pump having an inlet connected to a supply of material and a disc~large connected to a dispenser. ~OI-' precis-ion dispensillg, the dlspenser Inay include a valve which perm1ts I'luid to pass through a disc'harge opening such as a nozzl~ or f`luld tip. In some systems the dispenser valve is operated by a programmed con-trol device so that fluld :is disperlc:e(l in preci;e or metered arnounts.
In many applications it is of'ten desirable that precise patterns, metered amounts or both be dispensed. In operation, precision or accurat;e metering is af'fected by many ~actors including nozzle wear, fluid impurities, nozzle clogging, and pump perf'orrnance.
Clogging of the m.lterial flo~ path, espt:cially in the dispenser, is a typical problerm that adversely affects the perforrnance of precision dispensing systems. For example, in precision dispensing systems used to coat the interior surface f multipiece can bodies~ a clogged or worn nozzle may cause the can body to be incompletely or improperly coated.
12248ti~L
The ean ~,o~lles are typl~llly eoated clulirlg thc ~rOceS5 o~ manuracture at rates o~ up to many hundreds of c:an~ per rninute. Thlls, an improperly functioning dispenser anc] rr~ore partieularly a e]ogged or worn nozzle ean result in many improperly coated cans before deteetion by inspeetion or other known means. An improperly eoated ean may have an adverse effeet on the can's ability to function for storage. In some cases, tne ean may suffer accelerated deterioration (i.e., shorterled shelf lire), and in others (e.~. f(lr ~oods an~i bevera~s) the contents may be adversely a~`feeted (e.g., taste, spoilage). Irnproper coating, therefore, is undeslrable and may also be costly because cans that are lmproperly coated typically are not usable.
Other systems, for example, those involving the preeise deposition of tl,ermoplastles or similar material~s~, are also sus-ceptible to elogging. An exarnple of such a system is describecd in U.S. Patent l~o. ~1,166,2Ll6-~/latt. Thes(- systems are typieally used in the manufactllring of packaging (e.r;., cardboard cartons) and in product assembly. Clogging Or the dispensing system rnay result in defeet;ive products and in -turn result in delays or otherwise introduce undeslrab]e additlonal costs i~l the manu-factur:ing process.
Clog sensing s~stems heretofore known are not applic-able or useful for the accurate ancl prompt clog sel-lsing desired.
For exarrlple, U.S. Patent ~c. l!~072~93~ iller~ et al., discloses a method and apparatus for detecting blockages i~ a Vapol' flow line such as those used in liquid gasoline dispensing systems.
Sueh an apparatus would not be useful in a precision coatings application because the no~zle condition, whether clo~ged or worn, eannot be deterrnined. Hiller et al. de ermines whether a 12Z486~
alr,-~ (xlr~ts l~ V~ r)~ y ~ 3~rlrr t~ ! r'~ t;
.lde of t~,e elog an(~ l(tlviltl~r ~rl ;~ ln w~r~ dil~r~rl~la pressure exeeeds a predetermLned maximum value.
U.S. Patent No. 3,816,025-O'Neill dec~.~ribes a rluid eirculation system for a palnt spray installation. A seeondary reeireulation loop pressure sensor senses the pressure in the secondary loop dropping below a preseleeted valu~ :ln order to shut down t;he paint supply pump if a paint flow line should break.
U.S. Patent No. 4,315,317-Orehard et al. diseloses a measuring, eomputing and reeording system for monitoring of spray applicatLon parameters for pestieides dispensed from an aireraft. Orehard et al. records pressure in~orrrlation, total liquid volume, liquid flow rate, spray passes alld spray tlme.
The user is required to interpret the results of the items reeorded to determine whether amon~ other thlngs a clog eondi-tion i~ pre ent. Sueh a delay in system eondition determlnation is wholly unaeeeptable for precisiorl CO.ltirlg apl-lications sllch as the can body example 111ustrcited above.
U.S. Patent No. 3,482,781-Sharpe eontains a paint spray gun which uses air to atomize the paint during dispensing.
A pressure gauge is afflxed to the gun to indicate the pressure Or the atomLzing air cluring clispensing operatiorl. This deviee cannot accurately and reliab]y deterrrlirle wh~ther the paint flow path is clogged.
There is no -ystem pre-sently known which quic}ly ar,d automatically determines whether a dispenser is ap-plying a coating material in othe-r than a preselec-ted or desLred fashion.
~224861 Sl.1MMA~Y OF THF. lN~ENTION
In a system with a disperlser for fluid under pressure and a controller which provides o;.~eration si~nals to the dls-petlser tn control the open arld closcd condi.t;lon: thereof', a monitor evaluates dispenser operatiorl. The rnorli.tor has a sensor af`~lxed to the dispenser to sense the pressure o~ the fluld ln t~le dlsper-lser r~nd to generate ~ slgnal ref'lectlve of' the fluid prc~s3ur~a. A compara~or receLv~s both tile f']uid press-lre signal and a.n operatlon slgnal. T~e pressure slgnal is cornpared to first and second pressures. When the operation signal indicates the dispenser is open, the monitor will. generat~ a malfunc-tion signal if the pressure signal is not on or between the first and second pressures.
In a furt~ler ernt)odi.ment Or the instarl-t invention, a second conlparator corn~ares the I'luid preisure .;llrrlal to a pre-se:l.ected pressure value whcn the dl~spenser i.s not open. If the fluid pressure signal exceeds the plese]ectecl ~,ressure value, a rnalfullction signal is generated to lndicate t~at the system pump is malrunctioning or that the system fluid pressure is inadequate.
~RIEF Dr~, CRIPT`ION OF TIE DRAWINQS:
In the drawin~!s, which il~lu.-.tra-te the best mode presently contemplated:
Fig. l i~ a d:ia~-73rll of t~e instant ir.vention;
Fig. 2 is a b~oc~ dia~rarll ot` the morlltor~ de~icted :Ir ~5 Fi~. lj ~lg. 3 is a b:lock diagralll of an alternlte e!nbodirnent o~ the instant invention;
~224861 ;
Fig. ~l is a clrcuit d:Lagram of a pre-shaper circuit of'~ . 3;
F`ig. 5 is a eireuit diagram of the switch and sigJIal shaper of Fig. 3;
Fig. 6 is a circuit diagram of the ~irst si~nal eom-parator cireuit of Fig. 3;
Fi~;,. 7 is a circllit dlrlgram of th~ sl;r~tcher cJ-re~llt Or ~'lg. 3;
l'; a C~J'CUit diagram Or the Cl~llllp eircu:lt of n ~ig. 3;
Fig. 9 is a eireuit diagram of the seeond si~nal eomparator circuit of Fig. 3;
~ ig. 10 is a eireuil; diagraln of the ir-lformatiGn pro-cessor circuit of Fig. 3; and ~,5 i~'ig. 11 is a graph of wave forms at differellt pOilltS
in Figs. ~I through ln~ d~lring different phases Or tlrJe dispensing operation ~nd during dif'ferent; dic~.pens-irlg eorldit,ions.
~ESCR~PTT0N OF TIIE_PREFERRr.D_EMB0DIMENT
F`lg. 1 shows a monitor 15 connected in a dispensing system cornprised of primary dispenser ,?0, dis~enser eontroller 22 and fluid SOUl~Ce 30. The d-ispencer contro:ller 22 provides an enable signa'L via corldllc-t,ors 23 to e~ergi~t? solerJc)ià 2~1 which in turn opens a valve (not sho~n) in clispenser 20 to allow the fluid f'rom the souree 30 to ~]ow l-,h-iough noz~le 26. The fl~iid to be dispen.ced by dispenst;r 20 is eontinllously eireul-lred by a reeir~rocating pump -.1 -through a heated hose 32, dispens-er and hose 3~ as shown. A sensor ~0 is affi~ed to dispenser 20 to provide a signal reflective oE the pressure of the fluid within the dispenser 20.
The dispenser 20 is preferably of the type described and illustrated in copending Canadian Patent Application Serial No. 419,544, filed January 14, 1983, which is assigned to the assignee of the instant invention.
In a preferred embodiment of the instant invention, sensor 40 is a transducer which provides an electrical signal reflective of the pressure sensed. The signal is transmitted via conduc-tors 42 to the monitor 15. Monitor 15 also receives the enable signal provided by dispenser controller 26 via conductors 23 and 50. Monitor 15 compares the se~sed pressure signal to a preselected range of pressures each time an enable signal is generated by controller 22. The magnitude or value of pressures against which the sensor signal is compared are preselected empirically to be reflective of nozzle 22 being clogged or worn.
Switch 62, shown in Fig. 2, is a normally open switch which closes for the duration of the enable signal Erom controller 22. Upon closing of the switch 62, the sensor signal passes through to the signal shaper 6~, which changes the pressure signal into subs-tantially pulse form before it is transmitted to the signal comparator 66. C~mparator 66 compares the magnitude of -the pulse signal received from shaper 64 to preselected pressure values If the magnitude of the shaped signal is outside the range o preselected pressure values, a malfullction signal is supplied to output 68.
cw/, - 6 -~2Z48~1 In a preferred embodiment of the instant invention, monitor 15 also includes an information processor 70. Informa-tion processor 70 received the signal from the comparator output 68 and the enable signal from the controller 22 for example to increment a counter, or activate an alarm which may be audi~
ble, visual or both as selected by the user.
In the alternate embodiment shown in Fig. 3, monitor 15 receives an electrical signal from sensor 40 via conductors 42 to a pre-shaper (not shown). The pre-shaper conventionally pre-amplifies the AC and DC components of the pressure signal received from sensor 40 and inverts the pressure signal so that a drop in pressure is reflected by a positive signal amplitude.
The signal from controller 22 is transmitted through conductor 50 to a stretcher 100 which makes the enable portion of the control signal longer in time or stretched. The stretched control signal ensures that the portion of the controller signal which causes dispenser 20 to close will not be transmitted through monitor 15 until after the dispenser has actually closed.
The stretched signal is thereafter transmitted to OR gate 199 and second signal comparator 500 by conductor 101. The output of OR gate 199 follows the shape of the stretched pulse signal provided by conductor 101:if the signal on conductor 601 is low. Accordingly, a signal substantially identical to that transmitted from stretcher 100 to OR gate 199 is transmitted to the switch and signal shaper 200, first signal comparator 300 and information processor 600.
Switch and signal shaper 200 functions substantially the same as switch 62 and shaper 64 described hereinbefore and more fully illustrated in Fig. 5. The first signal comparator 301 compares the signal received via conductor 201 with ch/~ - 7 -~2248~1 a ~rl?selected band o~ pre~ure values whlch are re~lect~ve Or di.spenser 20 oper~in~r, irl ~ predetermlned mann~r. A m~lfunction sigr,al i~ ~enerated r~lectlve of this compari~n and transrnitted through comparator 301 to informatioll processor 600. Comparator 300 wlll only operate on the signal from conductor 201 when the dispenser 20 is enabled by the controller 22.
It should be noted that when the dispenser has not been enabled by controller 22 the s:lgnal from sensor 40 reflects :i.rirorlrlcl~;ion abollt th-~ thi.rd system all(l pump or:,c~ration. The pump circulates fluid from the fluid source throllgh disperlser 20 back to the rluid source. When a continuous action reciprocating pump is incorporated into the system, a pressure drop occurs between strokes. In a properly ~unctionLrlg purnp, SuC]l as rnanufactured by Nordson Corporation, Amherst, Ohio, this pressure drop is approxi-mate].y 30 to 40 psl. Should the pump perforrnance deteriorate>
for example because of worn seals, the pressure drop between strokes is approximate].y between 100 to 200 psi . Thus, corn-paring thi.s sigllal to a preselected pre:,sure va~Lue reflective of the pressllre in a properly operat:lng pump, ploper performance can be morlitored and mechai,ic.lL dt?fe(~ts 3UC~I ns . worn s~,al detected. This is accomplished by pc-sslrl~ the si~!;nal from t,he pre-shaper throu~h clamp 40n. Clamp 400 s~rves to suppress any DC components of the sensor signal ~rorn the preshaper and hold that portiorl of the si.gnal l~hen the pun;p is strol~ing, i.e., when a pressu-re drop is not Gccurril-lg, and c].amps or holds that portion at a zero value. The clamped signal is transmitted to a second signal comparator 500 by conductor 401.
~\ ~
i224861 Seeond signal eomparator 500 also reeeives the stretched pulse signal frorn eonduetor 101 so that the seeond sl~nal comparator 5G0 will not operate when dispcns~r 20 has been enabled. 1~ the elGamped ~ressure signal from conduetor JJol exeeeds a preseleete~ pressure value, eomparator 530 sends a malfunetion slgnal to information processor ~00.
In~orm~atiorl processor 600 reeeives si grnc~l S from OR
~ate 199, comparator 300 and eomparator 500. Arl embGdiment Or processor 600 will be more fu:l.ly described hereinafter, to indicate the type oI' malf~lnction, signi.f'icance of' malfunc-tion and/or activate an alarm or other remedial equipment. In the em~odiment of ~ig. 10, if a worn or clog~ed noz~le or worn pump .eal.s are detecte(l, inform~ltiorl pro~ec;sor (;30 trarlsmit.C; a signal to O~ gate 199, comparator 300 and comparator 500 to prevent the monitor 15 ~rom providin~ any further output. In effeet ~onitOr 15 wi.ll no lon~er provide malf'unct.lon signals due to conduetor 601 providing a high sinal to the output of OR
gate 199, disabling shaper 200 and rirst eomparison 300. As ~
be rnore fully described in conr,ection wi-th Fig. 10, this state cont:Lnues unti]. the monitor is reset.
Fig. 4 deplcts the pre-shaper includi.ng pre-amp].ifier 80 previously described. The arrangelTlent o:f resistors and capacitors of the values shown in Fig. 4 serves to smooth out the pressure signal renlo~ing un~Jclnted no:lse. Op~l-atio}lal amplifier 90 operaGes to only amplify the AC portion of the pressure signal. The signal appearinJ at point 96 is pro~-ided to the input o~ s~iteh and signal shaper 200 and clamp 430.
~224861 A circuit diagram of a preferred embodiment of switch and signal shaper 200 is shown in Fig. 5. The signal from the pre-shaper is first filtered by a high pass filter 201. The signal thereafter passes through analog switch 206. In the position shown in Fig. 5, switch 206 connects the signal from the pre-shaper to operational amplifier 210 and prevents capaci-tor 218 from discharging to ground at point 208 and is instead charged by amplifier 210. If the signal at point 198 forces switch 206 to move to the position opposite that shown, capacitor 218 will discharge to ground.
Calibration network 228 is used to calibrate opera-tional amplifier 220 to have a preselected voltage output. In this embodiment, the output voltage of operational amplifier 220 is calibrated to be 5 volts when dispenser 20 is functioning properly. To calibrate, variable resistor 222 is adjusted and the brightness of light emitting diodes 252 and 262 is thereby affected. Once the diodes are of a substantially even brightness, operational amplifier 220 has been calibrated.
The pre-shaped signal transmitted through conductor 201 is applied to the first signal comparator 300 which is shown in greater detail in Fig. 6. The signal from conductor 201 is the negative input of comparator 310 and the positive input of comparator 320. The reflective voltage as applied to comparators 310 and 320 establish the parameters of the range of preselected pressure values. Comparator 310 is arranged as an inverted comparator, such that its output remains at the level of the voltage at point 318 until the input voltage from conductor 201 approaches the input voltage at point 311, ch/~c - 10 -at which point the comparator forces its output to ground.
The reference voltage applied to input 311 is selected in the preferred embodiment by switch 316 connected to point A-B, B-C, or C-D.
Comparator 320 is arranged in Fig. 6 as a comparator, and does not have an inverted output. Operational amplifier 320 allows the voltage at point 324 to charge capacitor 330 in accordance with the time constant provided by resistor 326 and capacitor 330. Capacitor 330 will discharge through resistor 328 in accordance with the time constant associate with those two elements.
The outputs of comparators 310 and 320 is applied to the input of OR gate 340. The output of which is provided to the input 354 of OR gate 350. Schmitt trigger 360 is used to invert the output of OR gate 350 while Schmitt trigger 352 serves to invert the output from OR gate 199.
Referring back to Fig. 1, the signal from dispenser controller 22 is transmitted via conductors 50 to the stretcher circuit shown in Figure 7, which includes initially a diode bridge (102, 104, 106 and 108), and an optical isolator 110.
Capacitor 122 is charged in accordance with the time constant associated with capacitor 122 and resistor 124, so that until the threshold level of Schmitt Trigger 130 is reached a low output is generated on conductor 101 thereby extending the signal from controller 22. Low in this embodiment is ground.
The time constant is selected so that the output of trigger 140 remains high until after dispenser 20 has actually closed.
ch/~ - 11 -~.ZZ486~
The signal from the pre-shaper shown in Fig. 4 is applied to the input of clamp 400, as shown in Fig. 8, is transmitted via conductor 401 to the second signal comparator 500 shown in Fig. 9. The signal from conductor 401 passes through a variable resistor to the positive input of comparator 510 which is connected as a basic comparator. The variable resistor is adjusted so that the voltage level of the pressure signal is 2.5 volts when the dispenser is operating in an acceptable manner. Accordingly, as the signal from conductor 401 approaches the reference voltage which in this embodiment is 2.5 volts, the output of comparator 510 goes from ground to an open circuit.
While the output of comparator 510 remains grounded, the voltage at point 540 will travel to ground through the operational amplifier. When the output becomes an open circuit, the voltage at point 540 will travel through switch 530, closing the switch to point 532. Switch 530 is now latched closed and the voltage at point 540 will be transmitted via conductor 501 to information processor 600.
The OlltpUt of OR gate 199, traveling through diode 520, serves to maintain switch 530 in the position shown in Fig. 9, when dispenser 20 is enabled by a signal from controller 26. A signal transmitted from stretcher 100 to the input of OR gate 199 will force the output at point 198 to go low which in turn holds the voltage at the output of comparator 510 at a level insufficient for switch 530 to change positions.
ch/Jc - 12 -122486~
~ig. 10 is a schematic diagrarrl of an embodimerlt of in~ormatlon processor 600. This processor counts the number of tirr,-s the ~lispenser has dispensed materlal in an unacce~tablt?
fashion; it also lndicates whether~ the sensed prf-ssure is above o r below t~)e presel~-?ct;e(l r.~nÆe o~' r~rc~ re?s; ar~ lt, a'l.;o 1~
cates wl~ether thfe punll~ pr~e.,sure ls above ~he p3~ ctc?~l v~llue.
Processor 600 also provicles apparatus f'or reset,ting the systern a~ter a rna].~unction has been determi.ned and monitor 15 ceases to provi.de any further malfunctiorl indi.catlons, Y`~e in~ormation procfssor addltionall~ provides a si~,nal. at out~)ut 700 ~Jhich can be used to set ofl' an aucl:ltory alarm, or S}~l.lt ~ Wrl ~1 ('`JllVeyOr' line which may be; movingr, substrate beneath the dispenser.
Proc.-?ssor 600 :Lnc].udes a counter 620 ~laving its clock inpllt as the output ~rorn OR gate 199. The reset input of the courlter is connecteA ~,o conductor 30-L. ri r-ls ]1, ~, fJ and 5 are ~ nrl(~ d t;o r)-lns Ll, ,~, 5 .:Lrl(i 1,~ tl~J:l(x~ ',(). r~ c~
Or countcr ~)~'0 at pin. 1~, ~) ar~ ''('? al 5CJ c~ lllected to 1nv~?rter drivr~rs 621, 622 an(l 623 resl?e(,tive'l.y. The sifrnc-].:rrorn driver 621 passes through diode 624 and 625, which in this embodirrlent are IM41ll8 d:Lodes. I'h~s, a high si~,na~ appearin at pin 11 of counter 620 will cal~se a low sigrlal to appear at; the OUtpllt of driver 621, al]o~ring tne voltage to rlo~ from poirlt 631 throu~h lic~ t, emitti.ng diocle ~27. Drlver 622 and 623 operte in a similar rnanner, In Gile ernbodilnent, ].ight emitting diodes 627, 628 and 629 correspond to 2, l-l and c, respective consecutive courlts G ~ i spt-, n s er m~ 'UI ~' t :~. 0~1 .
T~l~? Ollt~:)ut (jf' IllU~t;~ 3n ~ rl~ ;t~l L-~ trlt .lnç.,u'c of Or~?. g-Lte 650. ']`he output ot~ ~F~c,at;f~ 6~ is COnlleCted to a driver inverter 660. In this embodiment all of the driver inverters depicted in Fig. 10 are Motorola MC11416s.
The output of multiplexer 630 is also provided to the enable input of OR gates 640A, 640B and 640C which in this embodiment are R-S flip-flops contained on a single electronic component such that unless the component is enabled, no output will appear at points QA, QB or QC. A Schmitt trigger inverter 604 has also been provided to this circuit.
The QA output of latch 640A is tied to ground so that a normally low signal may be applied to OR gate 199 so that the output thereof will generally follow the input provided from stretcher 100. When latch 640A is not enabled, the output at QA, QB and QC is seen as a high impedance. When the output of latch 640B becomes high, the output of driver 642 becomes low allowing the voltage applied to point 648 to flow through light emitting diode 645. Light emitting diode 646 is activated in a similar fashion.
When a high signal is provided through conductor 501 to processor 600, inverter driver 652 provides a low output, allowing the voltage at point 656 to flow through light emitting diode 654.
A reset input has also been provided, whereby inverter driver 670 and 672 provide a high signal to conductor 603 through diode 676 and to conductor 602 through diode 674.
Fig. 11 depicts four pressure wave forms which appear at point 96 of the pre-shaper shown in Fig. 5. Wave form A
is reflective of pump pressure. Wave form B is reflective of fluid pressure in the dispenser which is within the preselected ch/J ~ - 14 -12248~1 range. Wave form C is reflective of fluid pressure in the dispenser which exceeds the preselected range, for example a pressure greater than 60 PSI generally indicates a worn nozzle.
Wave form D lS reflective of fluid pressure in the dispenser 20 which is below the preselected range, for example a pressure less than 40 PSI generally indicates a clogged nozzle. The height of the wave form is in terms of voltage and the length of the wave form is in relation to time.
Wave form A signifies a pressure drop sensed between strokes of the reciprocating piston pump referred to hereinabove.
This signal is acted on when dispenser 20 is not enabled as shown by the wave form appearing at point 32. "Low" in the preferred embodiment refers to the signal being zero volts or grounded. When the signal at point 32 is continuously low, the signal at Point 198 is continuously high. Accordingly, latch 206 will be in the position opposite that which is shown in Fig. 5. Consequently, the wave form appearing at points 207 and 219 is a low signal. Since the signal at point 219 is continuously low, the output of comparators 310 and 320 at points 318 and 321 will be continuously high and continuously low respectively. This in turn provides a continuously high output from OR gate 340 to the input of OR gate 350 at point 354. With the wave form at point 198 continuously high, inverter 352 provides a continuously low input to OR gate 350 at point 353. Accordingly, the output of OR gate 350 will be continuous-ly high and the wave form appearing on conductor 301 is continuously low.
When the wave form at point 198 is high, switch 530 in Fig. 9 is vulnerable to change from the positon shown ch/i~- - 15 -lX248~1 to point 534 lf the pump pressure exceeds the reference established in comparator 510. For the purposes of illustra-tion, it is assumed that wave form A has exceeded the preselected pressure value. Consequently, point 198 is grounded and the voltage at point 540 flows through switch 530 latching it to point 534.
Wave form B of Fig. 11 represents an acceptable pressure condition in dispenser 20. Since the dispenser has been enabled, a signal of the type shown appears at point 32.
As previously described, dispenser 20 has an inherent mechanical delay between the time when the enabling signal is received and the time when the dispenser actually opens. This same condition occurs at the time of closing. These two conditions are depicted in Fig. 11 by the time periods designated 800 and 801 respectively.
Since dispenser 20 has been enabled, a signal will now appear at point 198. The stretched output at point 198 is designated 802. Since the wave form at point 198 becomes low, switch 206 will be in the position shown in Fig. 5. The wave form at point 207 will appear as shown in Fig. 11 and will be detected by operational amplifier 210 which serves to charge capacitor 218. Consequently, the signal appearing at point 219 is reflective of capacitor 218 charging and discharg-ing. The time of discharge causes the output of comparator 310 to remain low at point 318 until the capacitor has discharged to a point where its voltage is below the reference voltage applied at point 311. This period of time is designated 804 in Fig. 11. Since the voltage of the wave form at point 219 ch/J Q- - 16 -~.Z2486~
does not exceed the reference voltage at point 324 applied to comparator 320, the output at point 321 will remain continuously low. It becomes apparent that during the time period 804, OR gate 340 will have a low signal applied to inputs 342 and 344. Consequently, a pulse will appear in the wave form being transmitted by conductor 301. This pulse serves to reset counter 620, shown in Fig. l0 from having counted the rising edge of the wave form at point 198. This count has now been erased and no enabling signal is applied to the latches 640 A, B or C.
Wave form C is reflective of a high pressure drop in dispenser 20, which for example may be generally indicative of a worn dispenser nozzle in the can coating process described herein. Since the dispenser 20 has been enabled, a signal identical to that described in connection with wave form B is present at points 32 and 198. The wave form appearing at point 207 is similar to that appearing for wave form B except for magnitude. Consequently, the wave form appearing at point 219 is very similar to that discussed in connection with wave form B, except that its amplitude is higher. With this high signal at point 219, the output of comparator 310 at point 318 is generally identical to the wave form discussed in connection with wave form B, except that the time 804 may be slightly longer since capacitor 218 has been charged to a higher voltage. With the pressure drop of wave form C being so high, the reference voltage atpoint324 for comparator 320 has been exceeded, consequently, the voltage at point 324 will be allowed to charge capacitor 330 in accordance with the time constant of resistor 326 and capacitor ch/~r~ - 17 -122486~
330. This signal appears at point 321. When capacitor 218 has discharged sufficiently such that the input to comparator 320 is less than the reference voltage at point 324, capacitor 330 will discharge through resistor 328 to ground according to the time constant for those components. The discharge of the capacitor delays the voltage at point 321 from becoming zero because if a low signal is provided to inputs 344 and 342 of OR gate 340, a low signal will be provided to input 354 of OR
gate 350 which will force OR gate 350 to go temporarily low providing a false pulse to conductor 301. Accordingly, the time constant established by resistor 328 and capacitor 330 allows sufficient time, designated as 806 on Fig. 11, for the signal at point 318 to return to high. The resultant signal on conductor 301 is a continuous low. Since no pulse appears on conductor 301, counter 620 of information processor 600 is not reset and the rising edge at point 198 clocks the counter.
If counter 620 were to have counted a preselected number of consecutive pulses from OR gate 199, a signal is transmitted through multiplexor 630 to OR gate 650 and enables latches 640A, B and C. The point RA of latch 640A will receive a high signal wh:ile the point SA receives a low signal, provid-ing a high output at point QA. Schmitt trigger inverter 604 also provides a high signal to the inhibit input of multiplexor 630 through conductor 605. Since the output at QA is high, the output of OR gate 199 will remain high, effectively "freezing"
the system.
When the enable signal is provided by multiplexor 630, the latch 640C, for wave form C, has a high input at RC and a high input at SC
ch/'Q - 18 providing a low output at QC. The low output at QC in turn provides a high input at SB and after being inverted by inverter driver 644, provides a low input at RB providing a hlgh output at QB. The subsequent activation of light emitting diode 645 indicates that a high pressure drop condition has occurred.
Wave form D of Fig. 11 is reflective of a pressure drop in dispenser 20 which is too low indicating a clog. Since dispenser 20 has been enabled, a signal occurs at points 32 and 198 which has been discussed in greater detail in connection with wave form B. Switch 206 will thus be in the position shown in the drawings and the wave form at point 207 will be present. The charging of capacitor 218 again yields the wave form shown at point 219. The signal at polnt 219 is relatively smaller in amplitude such that neither of the reference voltages for comparators 310 or 320 is approached, consequently, the output at point 318 remains high and the wave form at point 321 remains low for the entire enabling time. Since a high-low signal is presented to the inputs of OR gate 340, a high output will be presented to input 354 of OR gate 350. Accordingly, OR
gate 350 will have a high output which will provide a low output signal by Schmitt trigger inverter 360 on conductor 301. As previously discussed, a low signal on conductor 301 permits counter 620 to count the pulse output of OR gate 199. If wave form D represents the appropriate number of consecutive counts by counter 620, multiplexer 630 will provide a high signal to OR
gate 650 and also enable latches 640A, B and C. Since the output of comparator 310 remains continuously high, a low signal will be applied to the RC input of latch 640C. As previously discuss-ed, a high signal is received at input SC. In the preferred embodiment, inverters have been placed before each of ch/3~ - 19 -"~
the inputs of latches 640A, B and C and the inl)ut:s of the fourth unused latch (not shown ln the drawirl~s) contained in the set have been eac}l ti.ed to ~rourld. ~nce enabled, the l.a1;ch 640C
wlll have a hl~,h out;r)llt al; QC. 'rhe act;.lval,ion ol' ll~ht emit~:lrlg cliode 646, indicates tha~ the pressure drop in dispenser 20 is too small.
Changes and modifications in the specifica].ly described embodiments can be carried out without departure from the scope of the invention which i.s intended to be limited on~Ly by the scope o.~ the appel^~dcd claims.
DISPLNSrR MALFUNCTION DETECTOR
BACK~.ROIJ~D O~ Tl~ VF.I~TION
FI~'~LL) _F TIIE IMVFNTION:
This invention relates to monitoring devices and more particularly relates to monitoring devices used to detect malful-lctionillg fluid dispensers.
STATEr`lE.`~T OF ART:
~ ,, . . _ Typical fluid dispensing systems in one form include a pump having an inlet connected to a supply of material and a disc~large connected to a dispenser. ~OI-' precis-ion dispensillg, the dlspenser Inay include a valve which perm1ts I'luid to pass through a disc'harge opening such as a nozzl~ or f`luld tip. In some systems the dispenser valve is operated by a programmed con-trol device so that fluld :is disperlc:e(l in preci;e or metered arnounts.
In many applications it is of'ten desirable that precise patterns, metered amounts or both be dispensed. In operation, precision or accurat;e metering is af'fected by many ~actors including nozzle wear, fluid impurities, nozzle clogging, and pump perf'orrnance.
Clogging of the m.lterial flo~ path, espt:cially in the dispenser, is a typical problerm that adversely affects the perforrnance of precision dispensing systems. For example, in precision dispensing systems used to coat the interior surface f multipiece can bodies~ a clogged or worn nozzle may cause the can body to be incompletely or improperly coated.
12248ti~L
The ean ~,o~lles are typl~llly eoated clulirlg thc ~rOceS5 o~ manuracture at rates o~ up to many hundreds of c:an~ per rninute. Thlls, an improperly functioning dispenser anc] rr~ore partieularly a e]ogged or worn nozzle ean result in many improperly coated cans before deteetion by inspeetion or other known means. An improperly eoated ean may have an adverse effeet on the can's ability to function for storage. In some cases, tne ean may suffer accelerated deterioration (i.e., shorterled shelf lire), and in others (e.~. f(lr ~oods an~i bevera~s) the contents may be adversely a~`feeted (e.g., taste, spoilage). Irnproper coating, therefore, is undeslrable and may also be costly because cans that are lmproperly coated typically are not usable.
Other systems, for example, those involving the preeise deposition of tl,ermoplastles or similar material~s~, are also sus-ceptible to elogging. An exarnple of such a system is describecd in U.S. Patent l~o. ~1,166,2Ll6-~/latt. Thes(- systems are typieally used in the manufactllring of packaging (e.r;., cardboard cartons) and in product assembly. Clogging Or the dispensing system rnay result in defeet;ive products and in -turn result in delays or otherwise introduce undeslrab]e additlonal costs i~l the manu-factur:ing process.
Clog sensing s~stems heretofore known are not applic-able or useful for the accurate ancl prompt clog sel-lsing desired.
For exarrlple, U.S. Patent ~c. l!~072~93~ iller~ et al., discloses a method and apparatus for detecting blockages i~ a Vapol' flow line such as those used in liquid gasoline dispensing systems.
Sueh an apparatus would not be useful in a precision coatings application because the no~zle condition, whether clo~ged or worn, eannot be deterrnined. Hiller et al. de ermines whether a 12Z486~
alr,-~ (xlr~ts l~ V~ r)~ y ~ 3~rlrr t~ ! r'~ t;
.lde of t~,e elog an(~ l(tlviltl~r ~rl ;~ ln w~r~ dil~r~rl~la pressure exeeeds a predetermLned maximum value.
U.S. Patent No. 3,816,025-O'Neill dec~.~ribes a rluid eirculation system for a palnt spray installation. A seeondary reeireulation loop pressure sensor senses the pressure in the secondary loop dropping below a preseleeted valu~ :ln order to shut down t;he paint supply pump if a paint flow line should break.
U.S. Patent No. 4,315,317-Orehard et al. diseloses a measuring, eomputing and reeording system for monitoring of spray applicatLon parameters for pestieides dispensed from an aireraft. Orehard et al. records pressure in~orrrlation, total liquid volume, liquid flow rate, spray passes alld spray tlme.
The user is required to interpret the results of the items reeorded to determine whether amon~ other thlngs a clog eondi-tion i~ pre ent. Sueh a delay in system eondition determlnation is wholly unaeeeptable for precisiorl CO.ltirlg apl-lications sllch as the can body example 111ustrcited above.
U.S. Patent No. 3,482,781-Sharpe eontains a paint spray gun which uses air to atomize the paint during dispensing.
A pressure gauge is afflxed to the gun to indicate the pressure Or the atomLzing air cluring clispensing operatiorl. This deviee cannot accurately and reliab]y deterrrlirle wh~ther the paint flow path is clogged.
There is no -ystem pre-sently known which quic}ly ar,d automatically determines whether a dispenser is ap-plying a coating material in othe-r than a preselec-ted or desLred fashion.
~224861 Sl.1MMA~Y OF THF. lN~ENTION
In a system with a disperlser for fluid under pressure and a controller which provides o;.~eration si~nals to the dls-petlser tn control the open arld closcd condi.t;lon: thereof', a monitor evaluates dispenser operatiorl. The rnorli.tor has a sensor af`~lxed to the dispenser to sense the pressure o~ the fluld ln t~le dlsper-lser r~nd to generate ~ slgnal ref'lectlve of' the fluid prc~s3ur~a. A compara~or receLv~s both tile f']uid press-lre signal and a.n operatlon slgnal. T~e pressure slgnal is cornpared to first and second pressures. When the operation signal indicates the dispenser is open, the monitor will. generat~ a malfunc-tion signal if the pressure signal is not on or between the first and second pressures.
In a furt~ler ernt)odi.ment Or the instarl-t invention, a second conlparator corn~ares the I'luid preisure .;llrrlal to a pre-se:l.ected pressure value whcn the dl~spenser i.s not open. If the fluid pressure signal exceeds the plese]ectecl ~,ressure value, a rnalfullction signal is generated to lndicate t~at the system pump is malrunctioning or that the system fluid pressure is inadequate.
~RIEF Dr~, CRIPT`ION OF TIE DRAWINQS:
In the drawin~!s, which il~lu.-.tra-te the best mode presently contemplated:
Fig. l i~ a d:ia~-73rll of t~e instant ir.vention;
Fig. 2 is a b~oc~ dia~rarll ot` the morlltor~ de~icted :Ir ~5 Fi~. lj ~lg. 3 is a b:lock diagralll of an alternlte e!nbodirnent o~ the instant invention;
~224861 ;
Fig. ~l is a clrcuit d:Lagram of a pre-shaper circuit of'~ . 3;
F`ig. 5 is a eireuit diagram of the switch and sigJIal shaper of Fig. 3;
Fig. 6 is a circuit diagram of the ~irst si~nal eom-parator cireuit of Fig. 3;
Fi~;,. 7 is a circllit dlrlgram of th~ sl;r~tcher cJ-re~llt Or ~'lg. 3;
l'; a C~J'CUit diagram Or the Cl~llllp eircu:lt of n ~ig. 3;
Fig. 9 is a eireuit diagram of the seeond si~nal eomparator circuit of Fig. 3;
~ ig. 10 is a eireuil; diagraln of the ir-lformatiGn pro-cessor circuit of Fig. 3; and ~,5 i~'ig. 11 is a graph of wave forms at differellt pOilltS
in Figs. ~I through ln~ d~lring different phases Or tlrJe dispensing operation ~nd during dif'ferent; dic~.pens-irlg eorldit,ions.
~ESCR~PTT0N OF TIIE_PREFERRr.D_EMB0DIMENT
F`lg. 1 shows a monitor 15 connected in a dispensing system cornprised of primary dispenser ,?0, dis~enser eontroller 22 and fluid SOUl~Ce 30. The d-ispencer contro:ller 22 provides an enable signa'L via corldllc-t,ors 23 to e~ergi~t? solerJc)ià 2~1 which in turn opens a valve (not sho~n) in clispenser 20 to allow the fluid f'rom the souree 30 to ~]ow l-,h-iough noz~le 26. The fl~iid to be dispen.ced by dispenst;r 20 is eontinllously eireul-lred by a reeir~rocating pump -.1 -through a heated hose 32, dispens-er and hose 3~ as shown. A sensor ~0 is affi~ed to dispenser 20 to provide a signal reflective oE the pressure of the fluid within the dispenser 20.
The dispenser 20 is preferably of the type described and illustrated in copending Canadian Patent Application Serial No. 419,544, filed January 14, 1983, which is assigned to the assignee of the instant invention.
In a preferred embodiment of the instant invention, sensor 40 is a transducer which provides an electrical signal reflective of the pressure sensed. The signal is transmitted via conduc-tors 42 to the monitor 15. Monitor 15 also receives the enable signal provided by dispenser controller 26 via conductors 23 and 50. Monitor 15 compares the se~sed pressure signal to a preselected range of pressures each time an enable signal is generated by controller 22. The magnitude or value of pressures against which the sensor signal is compared are preselected empirically to be reflective of nozzle 22 being clogged or worn.
Switch 62, shown in Fig. 2, is a normally open switch which closes for the duration of the enable signal Erom controller 22. Upon closing of the switch 62, the sensor signal passes through to the signal shaper 6~, which changes the pressure signal into subs-tantially pulse form before it is transmitted to the signal comparator 66. C~mparator 66 compares the magnitude of -the pulse signal received from shaper 64 to preselected pressure values If the magnitude of the shaped signal is outside the range o preselected pressure values, a malfullction signal is supplied to output 68.
cw/, - 6 -~2Z48~1 In a preferred embodiment of the instant invention, monitor 15 also includes an information processor 70. Informa-tion processor 70 received the signal from the comparator output 68 and the enable signal from the controller 22 for example to increment a counter, or activate an alarm which may be audi~
ble, visual or both as selected by the user.
In the alternate embodiment shown in Fig. 3, monitor 15 receives an electrical signal from sensor 40 via conductors 42 to a pre-shaper (not shown). The pre-shaper conventionally pre-amplifies the AC and DC components of the pressure signal received from sensor 40 and inverts the pressure signal so that a drop in pressure is reflected by a positive signal amplitude.
The signal from controller 22 is transmitted through conductor 50 to a stretcher 100 which makes the enable portion of the control signal longer in time or stretched. The stretched control signal ensures that the portion of the controller signal which causes dispenser 20 to close will not be transmitted through monitor 15 until after the dispenser has actually closed.
The stretched signal is thereafter transmitted to OR gate 199 and second signal comparator 500 by conductor 101. The output of OR gate 199 follows the shape of the stretched pulse signal provided by conductor 101:if the signal on conductor 601 is low. Accordingly, a signal substantially identical to that transmitted from stretcher 100 to OR gate 199 is transmitted to the switch and signal shaper 200, first signal comparator 300 and information processor 600.
Switch and signal shaper 200 functions substantially the same as switch 62 and shaper 64 described hereinbefore and more fully illustrated in Fig. 5. The first signal comparator 301 compares the signal received via conductor 201 with ch/~ - 7 -~2248~1 a ~rl?selected band o~ pre~ure values whlch are re~lect~ve Or di.spenser 20 oper~in~r, irl ~ predetermlned mann~r. A m~lfunction sigr,al i~ ~enerated r~lectlve of this compari~n and transrnitted through comparator 301 to informatioll processor 600. Comparator 300 wlll only operate on the signal from conductor 201 when the dispenser 20 is enabled by the controller 22.
It should be noted that when the dispenser has not been enabled by controller 22 the s:lgnal from sensor 40 reflects :i.rirorlrlcl~;ion abollt th-~ thi.rd system all(l pump or:,c~ration. The pump circulates fluid from the fluid source throllgh disperlser 20 back to the rluid source. When a continuous action reciprocating pump is incorporated into the system, a pressure drop occurs between strokes. In a properly ~unctionLrlg purnp, SuC]l as rnanufactured by Nordson Corporation, Amherst, Ohio, this pressure drop is approxi-mate].y 30 to 40 psl. Should the pump perforrnance deteriorate>
for example because of worn seals, the pressure drop between strokes is approximate].y between 100 to 200 psi . Thus, corn-paring thi.s sigllal to a preselected pre:,sure va~Lue reflective of the pressllre in a properly operat:lng pump, ploper performance can be morlitored and mechai,ic.lL dt?fe(~ts 3UC~I ns . worn s~,al detected. This is accomplished by pc-sslrl~ the si~!;nal from t,he pre-shaper throu~h clamp 40n. Clamp 400 s~rves to suppress any DC components of the sensor signal ~rorn the preshaper and hold that portiorl of the si.gnal l~hen the pun;p is strol~ing, i.e., when a pressu-re drop is not Gccurril-lg, and c].amps or holds that portion at a zero value. The clamped signal is transmitted to a second signal comparator 500 by conductor 401.
~\ ~
i224861 Seeond signal eomparator 500 also reeeives the stretched pulse signal frorn eonduetor 101 so that the seeond sl~nal comparator 5G0 will not operate when dispcns~r 20 has been enabled. 1~ the elGamped ~ressure signal from conduetor JJol exeeeds a preseleete~ pressure value, eomparator 530 sends a malfunetion slgnal to information processor ~00.
In~orm~atiorl processor 600 reeeives si grnc~l S from OR
~ate 199, comparator 300 and eomparator 500. Arl embGdiment Or processor 600 will be more fu:l.ly described hereinafter, to indicate the type oI' malf~lnction, signi.f'icance of' malfunc-tion and/or activate an alarm or other remedial equipment. In the em~odiment of ~ig. 10, if a worn or clog~ed noz~le or worn pump .eal.s are detecte(l, inform~ltiorl pro~ec;sor (;30 trarlsmit.C; a signal to O~ gate 199, comparator 300 and comparator 500 to prevent the monitor 15 ~rom providin~ any further output. In effeet ~onitOr 15 wi.ll no lon~er provide malf'unct.lon signals due to conduetor 601 providing a high sinal to the output of OR
gate 199, disabling shaper 200 and rirst eomparison 300. As ~
be rnore fully described in conr,ection wi-th Fig. 10, this state cont:Lnues unti]. the monitor is reset.
Fig. 4 deplcts the pre-shaper includi.ng pre-amp].ifier 80 previously described. The arrangelTlent o:f resistors and capacitors of the values shown in Fig. 4 serves to smooth out the pressure signal renlo~ing un~Jclnted no:lse. Op~l-atio}lal amplifier 90 operaGes to only amplify the AC portion of the pressure signal. The signal appearinJ at point 96 is pro~-ided to the input o~ s~iteh and signal shaper 200 and clamp 430.
~224861 A circuit diagram of a preferred embodiment of switch and signal shaper 200 is shown in Fig. 5. The signal from the pre-shaper is first filtered by a high pass filter 201. The signal thereafter passes through analog switch 206. In the position shown in Fig. 5, switch 206 connects the signal from the pre-shaper to operational amplifier 210 and prevents capaci-tor 218 from discharging to ground at point 208 and is instead charged by amplifier 210. If the signal at point 198 forces switch 206 to move to the position opposite that shown, capacitor 218 will discharge to ground.
Calibration network 228 is used to calibrate opera-tional amplifier 220 to have a preselected voltage output. In this embodiment, the output voltage of operational amplifier 220 is calibrated to be 5 volts when dispenser 20 is functioning properly. To calibrate, variable resistor 222 is adjusted and the brightness of light emitting diodes 252 and 262 is thereby affected. Once the diodes are of a substantially even brightness, operational amplifier 220 has been calibrated.
The pre-shaped signal transmitted through conductor 201 is applied to the first signal comparator 300 which is shown in greater detail in Fig. 6. The signal from conductor 201 is the negative input of comparator 310 and the positive input of comparator 320. The reflective voltage as applied to comparators 310 and 320 establish the parameters of the range of preselected pressure values. Comparator 310 is arranged as an inverted comparator, such that its output remains at the level of the voltage at point 318 until the input voltage from conductor 201 approaches the input voltage at point 311, ch/~c - 10 -at which point the comparator forces its output to ground.
The reference voltage applied to input 311 is selected in the preferred embodiment by switch 316 connected to point A-B, B-C, or C-D.
Comparator 320 is arranged in Fig. 6 as a comparator, and does not have an inverted output. Operational amplifier 320 allows the voltage at point 324 to charge capacitor 330 in accordance with the time constant provided by resistor 326 and capacitor 330. Capacitor 330 will discharge through resistor 328 in accordance with the time constant associate with those two elements.
The outputs of comparators 310 and 320 is applied to the input of OR gate 340. The output of which is provided to the input 354 of OR gate 350. Schmitt trigger 360 is used to invert the output of OR gate 350 while Schmitt trigger 352 serves to invert the output from OR gate 199.
Referring back to Fig. 1, the signal from dispenser controller 22 is transmitted via conductors 50 to the stretcher circuit shown in Figure 7, which includes initially a diode bridge (102, 104, 106 and 108), and an optical isolator 110.
Capacitor 122 is charged in accordance with the time constant associated with capacitor 122 and resistor 124, so that until the threshold level of Schmitt Trigger 130 is reached a low output is generated on conductor 101 thereby extending the signal from controller 22. Low in this embodiment is ground.
The time constant is selected so that the output of trigger 140 remains high until after dispenser 20 has actually closed.
ch/~ - 11 -~.ZZ486~
The signal from the pre-shaper shown in Fig. 4 is applied to the input of clamp 400, as shown in Fig. 8, is transmitted via conductor 401 to the second signal comparator 500 shown in Fig. 9. The signal from conductor 401 passes through a variable resistor to the positive input of comparator 510 which is connected as a basic comparator. The variable resistor is adjusted so that the voltage level of the pressure signal is 2.5 volts when the dispenser is operating in an acceptable manner. Accordingly, as the signal from conductor 401 approaches the reference voltage which in this embodiment is 2.5 volts, the output of comparator 510 goes from ground to an open circuit.
While the output of comparator 510 remains grounded, the voltage at point 540 will travel to ground through the operational amplifier. When the output becomes an open circuit, the voltage at point 540 will travel through switch 530, closing the switch to point 532. Switch 530 is now latched closed and the voltage at point 540 will be transmitted via conductor 501 to information processor 600.
The OlltpUt of OR gate 199, traveling through diode 520, serves to maintain switch 530 in the position shown in Fig. 9, when dispenser 20 is enabled by a signal from controller 26. A signal transmitted from stretcher 100 to the input of OR gate 199 will force the output at point 198 to go low which in turn holds the voltage at the output of comparator 510 at a level insufficient for switch 530 to change positions.
ch/Jc - 12 -122486~
~ig. 10 is a schematic diagrarrl of an embodimerlt of in~ormatlon processor 600. This processor counts the number of tirr,-s the ~lispenser has dispensed materlal in an unacce~tablt?
fashion; it also lndicates whether~ the sensed prf-ssure is above o r below t~)e presel~-?ct;e(l r.~nÆe o~' r~rc~ re?s; ar~ lt, a'l.;o 1~
cates wl~ether thfe punll~ pr~e.,sure ls above ~he p3~ ctc?~l v~llue.
Processor 600 also provicles apparatus f'or reset,ting the systern a~ter a rna].~unction has been determi.ned and monitor 15 ceases to provi.de any further malfunctiorl indi.catlons, Y`~e in~ormation procfssor addltionall~ provides a si~,nal. at out~)ut 700 ~Jhich can be used to set ofl' an aucl:ltory alarm, or S}~l.lt ~ Wrl ~1 ('`JllVeyOr' line which may be; movingr, substrate beneath the dispenser.
Proc.-?ssor 600 :Lnc].udes a counter 620 ~laving its clock inpllt as the output ~rorn OR gate 199. The reset input of the courlter is connecteA ~,o conductor 30-L. ri r-ls ]1, ~, fJ and 5 are ~ nrl(~ d t;o r)-lns Ll, ,~, 5 .:Lrl(i 1,~ tl~J:l(x~ ',(). r~ c~
Or countcr ~)~'0 at pin. 1~, ~) ar~ ''('? al 5CJ c~ lllected to 1nv~?rter drivr~rs 621, 622 an(l 623 resl?e(,tive'l.y. The sifrnc-].:rrorn driver 621 passes through diode 624 and 625, which in this embodirrlent are IM41ll8 d:Lodes. I'h~s, a high si~,na~ appearin at pin 11 of counter 620 will cal~se a low sigrlal to appear at; the OUtpllt of driver 621, al]o~ring tne voltage to rlo~ from poirlt 631 throu~h lic~ t, emitti.ng diocle ~27. Drlver 622 and 623 operte in a similar rnanner, In Gile ernbodilnent, ].ight emitting diodes 627, 628 and 629 correspond to 2, l-l and c, respective consecutive courlts G ~ i spt-, n s er m~ 'UI ~' t :~. 0~1 .
T~l~? Ollt~:)ut (jf' IllU~t;~ 3n ~ rl~ ;t~l L-~ trlt .lnç.,u'c of Or~?. g-Lte 650. ']`he output ot~ ~F~c,at;f~ 6~ is COnlleCted to a driver inverter 660. In this embodiment all of the driver inverters depicted in Fig. 10 are Motorola MC11416s.
The output of multiplexer 630 is also provided to the enable input of OR gates 640A, 640B and 640C which in this embodiment are R-S flip-flops contained on a single electronic component such that unless the component is enabled, no output will appear at points QA, QB or QC. A Schmitt trigger inverter 604 has also been provided to this circuit.
The QA output of latch 640A is tied to ground so that a normally low signal may be applied to OR gate 199 so that the output thereof will generally follow the input provided from stretcher 100. When latch 640A is not enabled, the output at QA, QB and QC is seen as a high impedance. When the output of latch 640B becomes high, the output of driver 642 becomes low allowing the voltage applied to point 648 to flow through light emitting diode 645. Light emitting diode 646 is activated in a similar fashion.
When a high signal is provided through conductor 501 to processor 600, inverter driver 652 provides a low output, allowing the voltage at point 656 to flow through light emitting diode 654.
A reset input has also been provided, whereby inverter driver 670 and 672 provide a high signal to conductor 603 through diode 676 and to conductor 602 through diode 674.
Fig. 11 depicts four pressure wave forms which appear at point 96 of the pre-shaper shown in Fig. 5. Wave form A
is reflective of pump pressure. Wave form B is reflective of fluid pressure in the dispenser which is within the preselected ch/J ~ - 14 -12248~1 range. Wave form C is reflective of fluid pressure in the dispenser which exceeds the preselected range, for example a pressure greater than 60 PSI generally indicates a worn nozzle.
Wave form D lS reflective of fluid pressure in the dispenser 20 which is below the preselected range, for example a pressure less than 40 PSI generally indicates a clogged nozzle. The height of the wave form is in terms of voltage and the length of the wave form is in relation to time.
Wave form A signifies a pressure drop sensed between strokes of the reciprocating piston pump referred to hereinabove.
This signal is acted on when dispenser 20 is not enabled as shown by the wave form appearing at point 32. "Low" in the preferred embodiment refers to the signal being zero volts or grounded. When the signal at point 32 is continuously low, the signal at Point 198 is continuously high. Accordingly, latch 206 will be in the position opposite that which is shown in Fig. 5. Consequently, the wave form appearing at points 207 and 219 is a low signal. Since the signal at point 219 is continuously low, the output of comparators 310 and 320 at points 318 and 321 will be continuously high and continuously low respectively. This in turn provides a continuously high output from OR gate 340 to the input of OR gate 350 at point 354. With the wave form at point 198 continuously high, inverter 352 provides a continuously low input to OR gate 350 at point 353. Accordingly, the output of OR gate 350 will be continuous-ly high and the wave form appearing on conductor 301 is continuously low.
When the wave form at point 198 is high, switch 530 in Fig. 9 is vulnerable to change from the positon shown ch/i~- - 15 -lX248~1 to point 534 lf the pump pressure exceeds the reference established in comparator 510. For the purposes of illustra-tion, it is assumed that wave form A has exceeded the preselected pressure value. Consequently, point 198 is grounded and the voltage at point 540 flows through switch 530 latching it to point 534.
Wave form B of Fig. 11 represents an acceptable pressure condition in dispenser 20. Since the dispenser has been enabled, a signal of the type shown appears at point 32.
As previously described, dispenser 20 has an inherent mechanical delay between the time when the enabling signal is received and the time when the dispenser actually opens. This same condition occurs at the time of closing. These two conditions are depicted in Fig. 11 by the time periods designated 800 and 801 respectively.
Since dispenser 20 has been enabled, a signal will now appear at point 198. The stretched output at point 198 is designated 802. Since the wave form at point 198 becomes low, switch 206 will be in the position shown in Fig. 5. The wave form at point 207 will appear as shown in Fig. 11 and will be detected by operational amplifier 210 which serves to charge capacitor 218. Consequently, the signal appearing at point 219 is reflective of capacitor 218 charging and discharg-ing. The time of discharge causes the output of comparator 310 to remain low at point 318 until the capacitor has discharged to a point where its voltage is below the reference voltage applied at point 311. This period of time is designated 804 in Fig. 11. Since the voltage of the wave form at point 219 ch/J Q- - 16 -~.Z2486~
does not exceed the reference voltage at point 324 applied to comparator 320, the output at point 321 will remain continuously low. It becomes apparent that during the time period 804, OR gate 340 will have a low signal applied to inputs 342 and 344. Consequently, a pulse will appear in the wave form being transmitted by conductor 301. This pulse serves to reset counter 620, shown in Fig. l0 from having counted the rising edge of the wave form at point 198. This count has now been erased and no enabling signal is applied to the latches 640 A, B or C.
Wave form C is reflective of a high pressure drop in dispenser 20, which for example may be generally indicative of a worn dispenser nozzle in the can coating process described herein. Since the dispenser 20 has been enabled, a signal identical to that described in connection with wave form B is present at points 32 and 198. The wave form appearing at point 207 is similar to that appearing for wave form B except for magnitude. Consequently, the wave form appearing at point 219 is very similar to that discussed in connection with wave form B, except that its amplitude is higher. With this high signal at point 219, the output of comparator 310 at point 318 is generally identical to the wave form discussed in connection with wave form B, except that the time 804 may be slightly longer since capacitor 218 has been charged to a higher voltage. With the pressure drop of wave form C being so high, the reference voltage atpoint324 for comparator 320 has been exceeded, consequently, the voltage at point 324 will be allowed to charge capacitor 330 in accordance with the time constant of resistor 326 and capacitor ch/~r~ - 17 -122486~
330. This signal appears at point 321. When capacitor 218 has discharged sufficiently such that the input to comparator 320 is less than the reference voltage at point 324, capacitor 330 will discharge through resistor 328 to ground according to the time constant for those components. The discharge of the capacitor delays the voltage at point 321 from becoming zero because if a low signal is provided to inputs 344 and 342 of OR gate 340, a low signal will be provided to input 354 of OR
gate 350 which will force OR gate 350 to go temporarily low providing a false pulse to conductor 301. Accordingly, the time constant established by resistor 328 and capacitor 330 allows sufficient time, designated as 806 on Fig. 11, for the signal at point 318 to return to high. The resultant signal on conductor 301 is a continuous low. Since no pulse appears on conductor 301, counter 620 of information processor 600 is not reset and the rising edge at point 198 clocks the counter.
If counter 620 were to have counted a preselected number of consecutive pulses from OR gate 199, a signal is transmitted through multiplexor 630 to OR gate 650 and enables latches 640A, B and C. The point RA of latch 640A will receive a high signal wh:ile the point SA receives a low signal, provid-ing a high output at point QA. Schmitt trigger inverter 604 also provides a high signal to the inhibit input of multiplexor 630 through conductor 605. Since the output at QA is high, the output of OR gate 199 will remain high, effectively "freezing"
the system.
When the enable signal is provided by multiplexor 630, the latch 640C, for wave form C, has a high input at RC and a high input at SC
ch/'Q - 18 providing a low output at QC. The low output at QC in turn provides a high input at SB and after being inverted by inverter driver 644, provides a low input at RB providing a hlgh output at QB. The subsequent activation of light emitting diode 645 indicates that a high pressure drop condition has occurred.
Wave form D of Fig. 11 is reflective of a pressure drop in dispenser 20 which is too low indicating a clog. Since dispenser 20 has been enabled, a signal occurs at points 32 and 198 which has been discussed in greater detail in connection with wave form B. Switch 206 will thus be in the position shown in the drawings and the wave form at point 207 will be present. The charging of capacitor 218 again yields the wave form shown at point 219. The signal at polnt 219 is relatively smaller in amplitude such that neither of the reference voltages for comparators 310 or 320 is approached, consequently, the output at point 318 remains high and the wave form at point 321 remains low for the entire enabling time. Since a high-low signal is presented to the inputs of OR gate 340, a high output will be presented to input 354 of OR gate 350. Accordingly, OR
gate 350 will have a high output which will provide a low output signal by Schmitt trigger inverter 360 on conductor 301. As previously discussed, a low signal on conductor 301 permits counter 620 to count the pulse output of OR gate 199. If wave form D represents the appropriate number of consecutive counts by counter 620, multiplexer 630 will provide a high signal to OR
gate 650 and also enable latches 640A, B and C. Since the output of comparator 310 remains continuously high, a low signal will be applied to the RC input of latch 640C. As previously discuss-ed, a high signal is received at input SC. In the preferred embodiment, inverters have been placed before each of ch/3~ - 19 -"~
the inputs of latches 640A, B and C and the inl)ut:s of the fourth unused latch (not shown ln the drawirl~s) contained in the set have been eac}l ti.ed to ~rourld. ~nce enabled, the l.a1;ch 640C
wlll have a hl~,h out;r)llt al; QC. 'rhe act;.lval,ion ol' ll~ht emit~:lrlg cliode 646, indicates tha~ the pressure drop in dispenser 20 is too small.
Changes and modifications in the specifica].ly described embodiments can be carried out without departure from the scope of the invention which i.s intended to be limited on~Ly by the scope o.~ the appel^~dcd claims.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A liquid dispensing and malfunction indicating system comprising:
a dispenser having a nozzle through which pressur-ized liquid is dispensed, said nozzle being capable of becoming a) clogged in which event said pressurized liquid is dispensed at a below-normal rate and b) worn in which event said pressurized liquid is dispensed at an above-normal rate, said liquid being dispensed at a normal rate when said nozzle is neither clogged or worn;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
a first reference signal source for providing a maximum pressure reference signal correlated to the maximum liquid pressure upstream of said valve when said valve is open and said nozzle unclogged;
a second reference signal source for providing a minimum pressure reference signal correlated to the liquid pressure upstream of said valve when said valve is open and said nozzle worn;
a source of control signals for repetitively selectively providing said first and second control signals to repetitively open and close said valve, respectively, to repetitively dispense controlled amounts of fluid from said nozzle;
comparison means responsive to said control signals and said pressure signals for comparing said pressure signal to said maximum and minimum pressure reference signals when said first control signal is output from said control signal source to open said valve; and nozzle malfunction means responsive to said comparator output only when said first control signal is present to open said valve for providing a nozzle malfunction output when said valve nozzle is clogged or worn in response to said pressure signal from said pressure transducer exceeding said maximum pressure reference signal or falling below said minimum pressure reference signal, respectively.
a dispenser having a nozzle through which pressur-ized liquid is dispensed, said nozzle being capable of becoming a) clogged in which event said pressurized liquid is dispensed at a below-normal rate and b) worn in which event said pressurized liquid is dispensed at an above-normal rate, said liquid being dispensed at a normal rate when said nozzle is neither clogged or worn;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
a first reference signal source for providing a maximum pressure reference signal correlated to the maximum liquid pressure upstream of said valve when said valve is open and said nozzle unclogged;
a second reference signal source for providing a minimum pressure reference signal correlated to the liquid pressure upstream of said valve when said valve is open and said nozzle worn;
a source of control signals for repetitively selectively providing said first and second control signals to repetitively open and close said valve, respectively, to repetitively dispense controlled amounts of fluid from said nozzle;
comparison means responsive to said control signals and said pressure signals for comparing said pressure signal to said maximum and minimum pressure reference signals when said first control signal is output from said control signal source to open said valve; and nozzle malfunction means responsive to said comparator output only when said first control signal is present to open said valve for providing a nozzle malfunction output when said valve nozzle is clogged or worn in response to said pressure signal from said pressure transducer exceeding said maximum pressure reference signal or falling below said minimum pressure reference signal, respectively.
2. The system of claim 1 wherein said pressurized liquid source includes a continuously operated reciprocating pump having an input and an output which causes the pressure of said liquid between the pump output and said valve to cyclically change between upper and lower pressure valves each pump stroke when said valve is closed and liquid is not being dispensed via said nozzle;
said system further including liquid bypass means interconnecting said source of pressurized liquid and conduit means upstream of said valve for recirculating said liquid from said pump output to said pump input when said valve is closed and liquid is not being dispensed via said nozzle; and means responsive to said second control signal and said pressure signal output from said pressure transducer for providing a pump malfunction indication if when the valve is closed the cyclical pressure change each pump stroke exceeds a specified differential pressure value corre-lated to proper pump operation.
said system further including liquid bypass means interconnecting said source of pressurized liquid and conduit means upstream of said valve for recirculating said liquid from said pump output to said pump input when said valve is closed and liquid is not being dispensed via said nozzle; and means responsive to said second control signal and said pressure signal output from said pressure transducer for providing a pump malfunction indication if when the valve is closed the cyclical pressure change each pump stroke exceeds a specified differential pressure value corre-lated to proper pump operation.
3. A liquid dispensing and malfunction indicating system comprising:
a dispenser having a nozzle through which pressurized liquid is dispensed, said nozzle being capable of becoming clogged in which event said pressurized liquid is dispensed at a below-normal rate, said liquid being dispensed at a normal rate when said nozzle is not clogged;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
a reference signal source for providing a maximum pressure reference signal correlated to the maximum liquid pressure upstream of said valve when said valve is open and said nozzle unclogged;
a source of control signals for repetitively providing said first and second control signals to repetitively open and close said valve, respectively, to repetitively dispense controlled amounts of fluid from said nozzle;
comparison means responsive to said control signals for comparing said pressure signal to said maximum pressure reference signal when said first control signal is output from said control signal source to open said valve; and nozzle malfunction means responsive to said compara-tor output only when said first control signal is present to open said valve for providing a nozzle malfunction output when said valve nozzle is clogged in response to said pressure signal from said pressure transducer exceeding said maximum pressure reference signal.
a dispenser having a nozzle through which pressurized liquid is dispensed, said nozzle being capable of becoming clogged in which event said pressurized liquid is dispensed at a below-normal rate, said liquid being dispensed at a normal rate when said nozzle is not clogged;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
a reference signal source for providing a maximum pressure reference signal correlated to the maximum liquid pressure upstream of said valve when said valve is open and said nozzle unclogged;
a source of control signals for repetitively providing said first and second control signals to repetitively open and close said valve, respectively, to repetitively dispense controlled amounts of fluid from said nozzle;
comparison means responsive to said control signals for comparing said pressure signal to said maximum pressure reference signal when said first control signal is output from said control signal source to open said valve; and nozzle malfunction means responsive to said compara-tor output only when said first control signal is present to open said valve for providing a nozzle malfunction output when said valve nozzle is clogged in response to said pressure signal from said pressure transducer exceeding said maximum pressure reference signal.
4. A liquid dispensing and malfunction indicating system comprising:
a dispenser having a nozzle through which pressur-ized liquid is dispensed, said nozzle being capable of becoming worn in which event said pressurized liquid is dispensed at an above-normal rate, said liquid being dispensed at a normal rate when said nozzle is not worn;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
a reference signal source for providing a minimum pressure reference signal correlated to the liquid pressure upstream of said valve when said valve is open and said nozzle worn;
a source of control signals for repetitively selectively providing said first and second control signals to repetitively open and close said valve, respectively, to repetitively dispense controlled amounts of fluid from said nozzle;
comparison means responsive to said control signals for comparing said pressure signal to said minimum pressure reference signal when said first control signal is output from said control signal source to open said valve; and nozzle malfunction means responsive to said comparator output only when said first control signal is present to open said valve for providing a nozzle malfunction output when said valve nozzle is worn in response to said pressure signal from said pressure transducer falling below said minimum pressure reference signal.
a dispenser having a nozzle through which pressur-ized liquid is dispensed, said nozzle being capable of becoming worn in which event said pressurized liquid is dispensed at an above-normal rate, said liquid being dispensed at a normal rate when said nozzle is not worn;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
a reference signal source for providing a minimum pressure reference signal correlated to the liquid pressure upstream of said valve when said valve is open and said nozzle worn;
a source of control signals for repetitively selectively providing said first and second control signals to repetitively open and close said valve, respectively, to repetitively dispense controlled amounts of fluid from said nozzle;
comparison means responsive to said control signals for comparing said pressure signal to said minimum pressure reference signal when said first control signal is output from said control signal source to open said valve; and nozzle malfunction means responsive to said comparator output only when said first control signal is present to open said valve for providing a nozzle malfunction output when said valve nozzle is worn in response to said pressure signal from said pressure transducer falling below said minimum pressure reference signal.
5. A liquid dispensing and malfunction indicating system comprising:
a dispenser having a nozzle through which pressur-ized liquid is dispensed;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
said pressurized liquid source including a continu-ously operated reciprocating pump having an input and an output which causes the pressure of said liquid between the pump output and said valve to cyclically change between upper and lower pressure valves each pump stroke when said valve is closed and liquid is not being dispensed via said nozzle;
liquid bypass means interconnecting said source of pressurized liquid and conduit means upstream of said valve for recirculating said liquid from said pump output to said pump input when said valve is closed and liquid is not being dispensed via said nozzle; and means responsive to said second control signal and said pressure signal output from said pressure transducer only when said valve is closed for providing a pump malfunction indication if when the valve is closed the cyclical pressure change each pump stroke exceeds a specified differential pressure value correlated to proper pump operation.
a dispenser having a nozzle through which pressur-ized liquid is dispensed;
a source of pressurized liquid;
liquid conduit means interconnecting said pressurized liquid source and said dispenser;
a control signal-operated valve connected between said dispenser nozzle and said source of pressurized liquid for controlling the flow of pressurized liquid to said nozzle, said valve being opened in response to a first control signal and closed in response to a second control signal;
a pressure transducer for sensing the pressure of said liquid upstream of said nozzle and providing a pressure signal correlated thereto;
said pressurized liquid source including a continu-ously operated reciprocating pump having an input and an output which causes the pressure of said liquid between the pump output and said valve to cyclically change between upper and lower pressure valves each pump stroke when said valve is closed and liquid is not being dispensed via said nozzle;
liquid bypass means interconnecting said source of pressurized liquid and conduit means upstream of said valve for recirculating said liquid from said pump output to said pump input when said valve is closed and liquid is not being dispensed via said nozzle; and means responsive to said second control signal and said pressure signal output from said pressure transducer only when said valve is closed for providing a pump malfunction indication if when the valve is closed the cyclical pressure change each pump stroke exceeds a specified differential pressure value correlated to proper pump operation.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US47420183A | 1983-03-10 | 1983-03-10 | |
| US474,201 | 1983-03-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1224861A true CA1224861A (en) | 1987-07-28 |
Family
ID=23882587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000448980A Expired CA1224861A (en) | 1983-03-10 | 1984-03-06 | Dispenser malfunction detector |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0119057B1 (en) |
| JP (1) | JPH0644204B2 (en) |
| CA (1) | CA1224861A (en) |
| DE (1) | DE3473236D1 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT380422B (en) * | 1984-04-25 | 1986-05-26 | Ver Edelstahlwerke Ag | LIQUID JET CUTTER |
| JPH0822422B2 (en) * | 1985-06-03 | 1996-03-06 | ノードソン株式会社 | How to manage the squirt pattern of a liquid |
| DE3532933A1 (en) * | 1985-09-14 | 1987-03-26 | Ransburg Gmbh | Safety-valve device for a coating system |
| JPH0356268Y2 (en) * | 1986-09-20 | 1991-12-17 | ||
| DE3713999A1 (en) * | 1987-04-27 | 1988-11-10 | Behr Industrieanlagen | METHOD FOR AUTOMATIC SERIAL COATING OF WORKPIECES |
| JPH05502624A (en) * | 1989-12-04 | 1993-05-13 | テック―エス インコーポレイテッド | Defect detection device and method in can end sealant coating machine |
| US5481260A (en) * | 1994-03-28 | 1996-01-02 | Nordson Corporation | Monitor for fluid dispensing system |
| DE19903827C1 (en) * | 1999-02-02 | 2001-03-22 | Daimler Chrysler Ag | Paint feed monitoring system for paint spray plant detects characteristic values for dosing pump and paint feed used for calculating dynamic viscosity of paint |
| SE513890C2 (en) | 1999-03-18 | 2000-11-20 | Plm Ab | Method and apparatus for monitoring fluid consumption |
| FR2855938A1 (en) * | 2003-06-16 | 2004-12-17 | Commissariat Energie Atomique | Parasites e.g. insects, eliminating device, has pulverization unit distributing active chemical product on receiving actuation signal representing condition of development of parasite when average values are within preset ranges |
| EP3094420B1 (en) | 2014-01-15 | 2022-03-09 | Gojo Industries, Inc. | Dispenser functionality evaluation |
| EP2962766B1 (en) * | 2014-06-30 | 2016-11-23 | ABB Schweiz AG | System and method for determining component-related delay times for the robotic spray application of viscous fluids |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3763380A (en) * | 1971-05-05 | 1973-10-02 | Stock Equipment Co | Method and apparatus for measuring rates of random pulses |
| FR2135505B1 (en) * | 1971-05-06 | 1973-11-30 | Tunzini Sames | |
| JPS49105228A (en) * | 1973-02-09 | 1974-10-04 | ||
| JPS5142768A (en) * | 1974-10-11 | 1976-04-12 | Masaaki Iwata | HATSUHOTAI HATSUNETSUSHIITO |
| US4313111A (en) * | 1980-05-12 | 1982-01-26 | Anderson Jack W | Nozzle condition monitor |
| US4420957A (en) * | 1981-10-26 | 1983-12-20 | Progressive Blasting Systems, Inc. | Monitor method and apparatus for particle blasting equipment |
-
1984
- 1984-03-06 CA CA000448980A patent/CA1224861A/en not_active Expired
- 1984-03-07 DE DE8484301516T patent/DE3473236D1/en not_active Expired
- 1984-03-07 EP EP84301516A patent/EP0119057B1/en not_active Expired
- 1984-03-10 JP JP59044854A patent/JPH0644204B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0119057B1 (en) | 1988-08-10 |
| EP0119057A2 (en) | 1984-09-19 |
| JPS59205619A (en) | 1984-11-21 |
| DE3473236D1 (en) | 1988-09-15 |
| JPH0644204B2 (en) | 1994-06-08 |
| EP0119057A3 (en) | 1986-01-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4668948A (en) | Dispenser malfunction detector | |
| CA1224861A (en) | Dispenser malfunction detector | |
| US5323547A (en) | Powder paint supply device | |
| US4917296A (en) | Spraying apparatus with flow alarm | |
| CA2115287C (en) | Apparatus and method for controlling the introduction of chemical foamant into a water stream in fire-fighting equipment | |
| US5301873A (en) | Low fluid indicator for pressurized canister | |
| EP2722500A2 (en) | System and method for dosing cylinder lubrication oil into large diesel engine cylinders | |
| AU600172B2 (en) | Spray gun control circuit | |
| CN106662098A (en) | Material dispense tracking and control | |
| US5473947A (en) | Fluidized powder flowrate measurement method and device | |
| US5176018A (en) | Shot sensing shot peening system and method having a capacitance based densitometer | |
| WO1995026523A1 (en) | Monitor for fluid dispensing system | |
| US20030000773A1 (en) | Additive nebulising device | |
| EP0061922B1 (en) | Method, and system, for spraying | |
| US5014645A (en) | Electrostatic spray coating system | |
| JP3462665B2 (en) | Spray lubrication device | |
| US5800876A (en) | Method and device for controlling the outflow of a fluidized solid from a container | |
| US5310114A (en) | Apparatus and method for measuring paint usage in a painting system | |
| US6423143B1 (en) | Voltage block monitoring system | |
| US5454518A (en) | Ultrasonic fogging device | |
| US20090242583A1 (en) | Variable flow air flow controller | |
| WO2004076075A1 (en) | Flow detection in liquid application systems | |
| US5709749A (en) | Solvent supply for paint sprayer | |
| JPH05633Y2 (en) | ||
| JPH0346337Y2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |