CA2565312C - Windshield de-icing - Google Patents
Windshield de-icing Download PDFInfo
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- CA2565312C CA2565312C CA002565312A CA2565312A CA2565312C CA 2565312 C CA2565312 C CA 2565312C CA 002565312 A CA002565312 A CA 002565312A CA 2565312 A CA2565312 A CA 2565312A CA 2565312 C CA2565312 C CA 2565312C
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- window
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Abstract
Apparatus (20) for cleaning a window (24) of a vehicle (22), including a vessel (28), having an inlet (32) through which a washing fluid is received from a reservoir and an outlet (34) through which the fluid is discharged for cleaning the window. There is a heating element (50) for heating the fluid in the vessel, which element preheats the vessel before the washing fluid is received therein, whereby at least an initial quantity of the fluid is rapidly heated and discharged from the vessel.
Description
la WrNDSI~LD 1~E-ICING
FIELD OF THE INVENTION
The present imnention relates generally to fluid heating, and specifically to h'tating of a fluid for the purpose of cleaning or do-icing as automobile windovY.
EACKGROUND OF THE 1NVENT~N
Various methods and devices are Imown in the art for providing a spray of heated water or other washing fluid onto the windows of a vehicle. The heated fluid is particularly advantageous in removing ice from the vehicle windshield in co?ad weather.
?his ice removal function requires that a driver of the vehicle wait while the fluid is heated, before the windshield can be de-iced. Methods and devices laiowa in the art are uapractical for this purpose, however, since they typically use heat or electricity generated by the vehicle engine itself to heat the fluid, reqe:hiag the driver to wait an unacceptably long tithe for the fluid to reach a suitable temperature.
Using the vehicle battery to heat, the fluid, independent of the vehicle end is also pmblematic because of the large current draw required to heat a . sufftciem quaatity~ of fluid to effectively de-ice the windshield. The battery cannot typically provide sufficient curnem to heat the vehicle's entire reservoir of washing fluid in a reasonable amount of time. Although methods and devices have been suggested for heating the fluid online, as it is about to be sprayed on the windshield, the battery also cannot provide enough to heat a spray of sufficietn vohime to a high enough temperattue to achieve effective de-icing.
U. S. Patent 5,509,606 describes a hot wash device for as ;automobile windshield, which a cornaiutr into which washing fluid from a reservoir is pumped and in which the $uid is heated by an electrical heating element before it is sprayed onto the windshield. The container is insulated and inchides a thermostat that is used to ehsure that the teaipaature of the fluid does not tied a predtterminod mmdmum. The cozitaiaer is kept full, with heat applied as needed to bring the cold fluid pumped into the ~eonxaiaer up to the desired temperature.
FIELD OF THE INVENTION
The present imnention relates generally to fluid heating, and specifically to h'tating of a fluid for the purpose of cleaning or do-icing as automobile windovY.
EACKGROUND OF THE 1NVENT~N
Various methods and devices are Imown in the art for providing a spray of heated water or other washing fluid onto the windows of a vehicle. The heated fluid is particularly advantageous in removing ice from the vehicle windshield in co?ad weather.
?his ice removal function requires that a driver of the vehicle wait while the fluid is heated, before the windshield can be de-iced. Methods and devices laiowa in the art are uapractical for this purpose, however, since they typically use heat or electricity generated by the vehicle engine itself to heat the fluid, reqe:hiag the driver to wait an unacceptably long tithe for the fluid to reach a suitable temperature.
Using the vehicle battery to heat, the fluid, independent of the vehicle end is also pmblematic because of the large current draw required to heat a . sufftciem quaatity~ of fluid to effectively de-ice the windshield. The battery cannot typically provide sufficient curnem to heat the vehicle's entire reservoir of washing fluid in a reasonable amount of time. Although methods and devices have been suggested for heating the fluid online, as it is about to be sprayed on the windshield, the battery also cannot provide enough to heat a spray of sufficietn vohime to a high enough temperattue to achieve effective de-icing.
U. S. Patent 5,509,606 describes a hot wash device for as ;automobile windshield, which a cornaiutr into which washing fluid from a reservoir is pumped and in which the $uid is heated by an electrical heating element before it is sprayed onto the windshield. The container is insulated and inchides a thermostat that is used to ehsure that the teaipaature of the fluid does not tied a predtterminod mmdmum. The cozitaiaer is kept full, with heat applied as needed to bring the cold fluid pumped into the ~eonxaiaer up to the desired temperature.
U. S. Patent 5, I 1 S, 040 describes electric apparatus for washing window glass of a vehicle. Aa insulated container is positioned between a reservoir of cold washing fluid and spray outlets to the vehicle window, in a position lower than the 'reservoir so as to be kept full of fluid. When the vehicle ignition is turned on; an electric heater heats the fluid in the comainer and remains active while the vehicle is in use. There as no provision, however, for rapid start-up and heating to de-ice the vehicle window.
U.S. Patent 4,090,668 describes a windshield washing and deicing system which includes a reservoir having a sealed container therein. A pump transfers washer fluid from the reservoir to the container and from the container to a pluralittt of nozzles.
Heated engine IO coolant is passed through a conduit in the reservoir. Electrical resistance wire heats the fluid in the container whenever the temperature drops below a certain minimum. Solenoid valves direct the spray from the tank to the front or rear window of the vehicle, but there is no suggestion of using the valves for any other fluid control purposes.
U.S. Petern 5,012,977 describes a vehicle window wasters is which washer fluid in a reservoir is heated, and in which a pump for spaying the fluid on the vehicle window has a variable outlet pressure. The temperature of the fluid in the reservoir is sensed, and the pump outlet pressure is varied accordingly in an inverse manner with temperature of the washer fluid, so as to maintain a more consistent fluid deposit an the window, as the fluid viscosity changes with temperature.
U.S. Patern 5,354,965 describes a system for electrically hLating a volume of windshield cleaning fluid in a motor vehicle. A vessel is filled with the volume of fluid to be heated, using PTC thermistors or other elecuical heating elements. A control circuit regulates the length of time that the fluid is heated, in accordance with a prevailing ambieat temperature, before the fluid is sprayed on the windshield. The circuit also prevents operation of the fluid heating when the vehicle engine is not runnier.
U.S. Patent 4,090,668 describes a windshield washing and deicing system which includes a reservoir having a sealed container therein. A pump transfers washer fluid from the reservoir to the container and from the container to a pluralittt of nozzles.
Heated engine IO coolant is passed through a conduit in the reservoir. Electrical resistance wire heats the fluid in the container whenever the temperature drops below a certain minimum. Solenoid valves direct the spray from the tank to the front or rear window of the vehicle, but there is no suggestion of using the valves for any other fluid control purposes.
U.S. Petern 5,012,977 describes a vehicle window wasters is which washer fluid in a reservoir is heated, and in which a pump for spaying the fluid on the vehicle window has a variable outlet pressure. The temperature of the fluid in the reservoir is sensed, and the pump outlet pressure is varied accordingly in an inverse manner with temperature of the washer fluid, so as to maintain a more consistent fluid deposit an the window, as the fluid viscosity changes with temperature.
U.S. Patern 5,354,965 describes a system for electrically hLating a volume of windshield cleaning fluid in a motor vehicle. A vessel is filled with the volume of fluid to be heated, using PTC thermistors or other elecuical heating elements. A control circuit regulates the length of time that the fluid is heated, in accordance with a prevailing ambieat temperature, before the fluid is sprayed on the windshield. The circuit also prevents operation of the fluid heating when the vehicle engine is not runnier.
SI~dA3tY OF T~ ~NVEN2X0~
It is aoa obpect of the print invention to provide improved epparedns for deaning a vehicle window.
According to the present invention there is provided ~ for deaaing a window of a vehicle a vessel having an inlet through which a washiu~g fluid is received from a reservoir and an owlet trough which the fluid is dis~srgod for deaning die window. The gPpmratus also ia~udes a hewing elammt Eor lreebag the fluid in the vessel, a tempesat~c saasx which senses a range of ternperetwcea in the vessel arrd a controller for c~rotliag flow of the fluid IO through the vessel. The ooatroller is i~ ekc~ricat oo~oumnaicarion with tax tomperaetra seasoar ao sutomaticstly and iatarmit~ntty releases. qusof the Said through the oat a desiirod teainpearat~u~e is raspoa to the temp~attaes s~sad by the sear $ pref~ed e~mbodiac:e~s of tlx iaves~o~ a vessel. is provid~od for $
,oo~sshlag did bsgoat the $e:id i~ discd~ocg~ed reward a. ofla . 8~o~rs tba did is IS ihttoduced into the v~ t3x vessel is pfd, pa~rabTy bg passing alt el~ciml u>:r~
a big in the vesse3 for about ome 'or less. Whm plug is comnpleted, the Said is allowed late the vessel and is bested ~r contact tl:~w~h, leading to an increase is pr~a~ iat the vessel due to vaporizstioa of a portion of the .. The $uid is sbrn fed at a desa~ed ~e and pr~ae so as to Win. andlo~c derice~ tire 20 window Ahhe~ t3tc pr~ao~ of the viesset draws only a modem c>earical iaptu from the eddde batoacy, it .a qusr~y of Lot fluid to be g~cr~ed Soc aea~g tlx ~~i~daar before stag tlu v~icda more raptly titan is any pzscdcad window deanoang sys»an kaarova is the art. Moreover, the pressure grated by vapoQiz:daa of the $uid beige to deer ZS ice or other btod~s that may base iti Zub~g or ao~tes though whch tba t3oid is spayed onto the ~ov~adoW It is also anted that sprspiag the toted fluid ~ the wiaddw's exterior smrfsce a~Ctively defogs its iataior senfaee, as ~a~.
Ia soma prafared embodimenots of the prramt iaventie~ p$er as im~tal qust~ty of tiu $uid has base hotbed and discbasgod from tlu vesad, a ~rther qyn~y is fed into the 30 v~a~el and dy bested. 4s~ce the futlxer qoan:ity 1~ ra desired tmaparatur~
it too is discharged, padera~y s8er 8 delay ~ sets. This process copes Sot repeated lxat/disGhanrge cycles, until the window has been cornpictety deaned and de-iced.
3a pr~xably, the ~ca~tcar~C cyc~ are ti~xed in a sequarcc whose para~natars~ such as discharge duoratioa. aad in~erva3s be~rovaca disc~aoc~os, are vaznod is a~coac~taa~ca wilt tm~ratur~ of't?ic v~ic~e and the 8irid.
Xt w4Ii be tmd~tood tact the te~cm "vehicle" as uxd is the coatexc of the pact pit apps and is the claims aan rifer to say type of whxiod ve~cle l~riag ovir~dorovs, such as as atzcomebile oor tracts, as well at to ~a boat or aizplane. Poao~r~ the z~
'~rindow."
ahhough typbcaB~r reg to- the windahieZd of a vehicle, caa refer to at:y traasparant including side and rear windows and outer mirrors, as well as covers of headliglus and the like.
In addition, whenever the term "cIeanirig" is used in the present application and in the claims in reference to an action involving spraying heated fluid on a window, the term will be understood to comprehend de-icing, as well. Those skilled in the art ~n'lI appreciated that the priaaples of the present invention may he adapted for cleaning and de-icing other surfaces, inesudiag internal windows and mirrors, far exataple, as well as for supplied heated water and fluid for other purposes.
There is therefore provided, in accordance with a preferred embodiment of the presem imrention, apparatus for cleaning a window of a vehicle, including:
20 a vessel, having an inlet through which a washing fluid is received from a reservoir and an outlet through which the fluid is discharged for cleaning the window; and a heating element for heating the fluid in the vessel, which elenneut preheats the vessel before the washing fluid is received therein, whereby at least an initial quantity of the fluid is rapidly heated and discharged from the vessel.
Preferably, the vessel is at least partly drained of fluid held therein before the element preheats the vessel, wherein the vessel includes a drain valve, actuated is cooperation with operation of the heating element, through which the vessel is at least partly drained. Preferably, the drain valve includes a one-way valve. Further preferably, the fluid drains into the reservoir, substantially irrespective of the height of the reservoir relative to the vessel.
Preferably, the apparatus includes a pump, which comreys the fluid from the reservoir to the vessel after the element preheats the vessel, wherein the pump and the reservoir are preferably part of a pre-existing window cleaning system is the vehicle, into which the vessel and beating element are retrofitted. Alternatively, the entire apparatus may be produced as an integral unit, including the pump. Preferably, the rapid heatir~ of the initial quantity of the $uid causes the fluid to be discharged at a pressure substantially higher than a pressure generated by the pump at the iulet of the vessel.
Preferably, the apparatus includes are or more valves, which regulate passage of fluid through the vessel responsive to operation of the heatiao clement, wherein the one or more valves open and close is cooperation with operation of the heating element.
Preferably, the one or more valves include a solenoid valve or alternatively, a hydraulic, pneumatic or vacuum-operated valve. At least one of the one or more valves is preferably fixed to the inlet of the vessel or, alternatively or additionally, to the outlet of the vessel, wherein the at least one valve _ CA 02565312 2006-11-14 fixed to the outlet opetrs responsive to a pressure increase in the vessel, due to comact beta~n the fluid and the preheated vessel Ia a preferred embodiment, the apparatus includes one or more temperature sensors, which generate signals responsive to an operating temperature of the apparatus, and a S controller, which receives the signals and regulates discharge of the $uid from the vessel responsive thereto. Preferably, after the initial quantity of the fluid is discharged, one or more additional quan:ities of fhud are refilled into the vessel and discharged therefrom intermittently, responsive to the temperature signals, wherein the quantities are discharged when the ternperaturc signals indicate that the temperature of the $uid in the vessel is above a predeterniined threshold, and the discharge is interrupted whsn the temperature of the fluid falls below the threshold. Alternatively or additionally, the quantities are controlled according to a predetermined timing sequence, which is selected responsive to the temperature signals, and the temperature threshold may vary among the quantities is the sequence.
In aaotba prefee:ed embodiment, the controller analyzes the signals to detect a malfunction of the apparatus and interrupts operation of the heating elemart whey the malfunction is detected.
Preferably, at least one of the one or morc temperature sensors is insade the vessel. The at least one sensor is preferably substantially immersed in the fluid in the vessel. Alternatively, the at least one sensor is positioned so as to be substantially out of the fluid in the vessel while the heating element preheats the vessel. Preferably, operation of the heating element is interrupted when the temperature inside the vessel exceeds a predetermined ma~mum.
In a preferred embodiment, at least one of the one or mare temperature sensors is faced on an outer surface of the vessel. Additiaaally or alternatively, at least one of the one or more temperature sensors is fixed to the reservoir or on an outer surface of the vehicle, most preferably on an outer surface of the window to be cleaned, covered by an at least partially re$ective cover, so as to substantially neutralize the effect of solar radiation thereon.
Preferably, the fluid in the vessel is heated to a temperature which is varied responsive to the signals generated by the at least one sensor feed on the outer sutFace of the vehicle, or otherwise responsive to a temperature outside the vehicle.
Preferably, the vessel 'racludes as inner compartment communicating with the outlet, is which compartment the ~iag element is positioned, and an outer compartment, generally surrounding the inner compartment, com~nicating with the inlet. Preferably, the vessel includes an insulating outer envelope substantially surrounding the outer compartment and a wall between the inner and outer compartments, which is preheated by the heating element.
Alternatively, the outer compartment is surrounding by one or more additional fluid compartments, extcmal thereto.
S Preferably, the apparatus includes a pressure relief valve.
Further preferably, the apparatus includes a bypass line, bypassing the vessel, through which the fluid is conveyed to clean the window without heating the fluid, wherein when cleaning of the window is required while the element is preheating the vessel, the fluid is diverted through the bypass line. Preferably, an operator of the vehicle selects whether the IO heating apparatus is to be actuated, such that when the apparatus is de-actuated, fluid is conveyed through the bypass. Further preferably, the apparatus automatically switches between conveying the fluid through the vessel and through the bypass, responsive to a heating cycle of the vessel. When fluid is not available from the vessel, unheated fluid is, preferably, automatically conveyed through the bypass line.
15 xn a preferred embodiment, the apparatus includes a remote input device, which is actuated by a user of the vehicle to initiate preheating of the vessel lxforo starting the vehicle.
Preferably, the heating element includes a resistive heating wire.
Alternatively or additionally, the heating element conveys heat from a heat source in the vehicle to the fluid in the vessel.
20 There is also provided, in accordance with a preferred embodiment of the present invention, apparatus for cleaning a window of a vehicle, including:
a vessel, having an inlet through which a washing fluid is received from a reservoir and an outlet through which the fluid is discharged for cleaning the window;
a heating element for heating the fluid in the vessel;
25 a temperature sensor, which senses a temperature in the vessel; and a valve for controlling flow of the fluid through the vessel, which intermittently releases quantities of the fluid through the outlet at a desired temperature, responsive to the temperature sensed by the sensor.
Preferably, a windshield wiper is activated intermittently to clean the window responsive 30 to the intermitxem release of the fluid.
Preferably, the apparatus includes a controller, which regulator the iatezmitteat release of the fluid according to a given timing sequence, preferably a predetermined or programmable sequence, whereon the timing sequence is varied responsive to an ambient temperature in the vehicle or, alternatively or additionally, to a temperature of as outer surface of the window.
Preferably, an initial quantity of the $uid is released ax a substantially higher pressure thaw subsequent quantities.
There is further provided, in accordance with a preferred embodiment of the present invention, a method for cleaning a window of a vehicle using a washing $uid, including:
preheating a vessel;
introducing a quantity of the fluid into the preheated vessel, whereby the temperature and pressure of the fluid are elevated; and discharging the fluid onto the window at the elevated tempacature and pressure.
Preferably, the vessel isof fluid before preheating the vessel.
Further prektably, introduciang the fluid includes pumping the fluid into the vessel at a pump pressure, wherein the elevated pressure at which the $uid is discharged is substaatialty Beater than the pump pressure.
In a preferred embodiment, the method includes measuring a temperature of the $uid, wherein discharging the $uid includes controlling the $uid discharge responsive to the temperature measurement. Additionally or alternatively, a temperature of an outer surface of the vehicle is measured, wherein discharging the fluid includes controlling the fluid discharge responsive to the tempe<ahue of the outer surface.
There is nnoreover provided, in accordance with a preferred embodiment of the present invention, a method for cleaning a window of a vehicle using a washing $uid, including repeating a plurality of times in sequence the steps of.
heating a quantity of the fluid;
monitoring a temperature of the quantity of the fluid; and discharging the quantity when a predetermined condition on the heating of the $uid is satisfied.
preferably, the predetermined condition is satisf ed when the temperature of the quanfrty of the $uid reaches a selected level. Alternatively or additionally, the predetermined condition is satisfied when a predetermined period of time has dapsed since begimaing the heating.
There is fiuthermore provided, in accordance with a preferred embodiment of the pr~eat ion, vehicle windshield de-icing apparatus inclirdiag: a plurality of individual heating units; and a mufti jacketed housing wherein each jacket surrounds one of the heating units, the jackets being interco~eeted by fluid conduits, inchiding an inlet and outlet port, the housing being connected at the inlet port to a windshield washer fluid source and at the outlet port to a windshield spray head, the heating units hang operated to heat the v~ashar fluid during flow to the windshield spray head, the heated sprayed fluid providing a windshield de-icing effect.
There is additionally provided, in accordance with a preferred embodiment of the present invention, an clectricalIy powered windshield de-icing device for vehicles, including a healable container for windshield washing said connectable between a washing fluid reservoir and a spray heads opposite the windshield, and provided with an inlet port sad an outlet port for the fluid, and having an elecuic heater element disposed inside the healable container, the rernainir~, liquid capacity of the heatable container not exceeding 300 ml, the heater element being connectable to the vehicle battery and being sized to heat the fluid contained in the healable eomainer to de-icing temperature rxrithin no more than one minute of actuation.
The present im~ention will be more fully understood from the following detaiied 1 S description of the preferred embodiments thereoiz taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRA'oVIINGS
Fig. 1 is a schematic, pictorial illustration showing apparatus for cleaning a windshield of an automobile with heated washing fluid, in acwrdance with a preferred embodiment of the presern imreation;
Fig. 2 is a schematic diagram showing details of the cleaning apparatus of Fig. 1, in accordance with a prefezrod embodiment of the present invention;
Fig. 3 is a schematic illustration showing a temperature sensor on the windshield of the automobile of Fig. 1, in accordance with a preferred embodiment of the present invention;
Fig. 4 is a schematic block diagram illustrating the functions of an electronic controller in the apparatus ofFig. 1, in accordance with a preferred embodiment ofthe present invention;
Fig. 5 is a timing diagram illustrating operation of the apparatus of Fig. 1, is accordance with a preferred enzbodimetn of the present imientioa;
Fig. 6 is a schematic diagram showing details of windshield cleaning apparatus, in accordance with another preferred embodiment of the present invention;
Fig. 7 is a sections! view of a healable vessel for use in windshield cleaning apparatus, in accordance with a preferred anbodimeat of the present imrention;
Fig. 8 is a sectional view of a healable vessel for use in windshield cleaning apparatus, in accordance with another preferred embodiment of the present mention;
Fig. 9 is a perspective view of a heatable vessel for use in held cleaning apparatus, in accordance with still another preferred embodiment of the present invention;
Fig. 10 is as electrical schematic diagram shoaring the connection of heating units in the vessel of Fig. 9, in accordance with a preferred embodim~t of the present invention;
Fig, 1 l is a side view of an internal portion of the vessel of Fig. 10, in accordance with a preferred embodinnart of the presont invention;
Fig. 12 is a cross-sectional view of the vessel of Fig. 11, taken along line ~I I~I;
Figs. 13A and 13B arc, respectively, top and sectional side views of the vessel of Fig.
I 1, the sectional view taken along line ~-X~;
Fig. 14 is a schematic pictorial illustration showing window cleaning apparatus in an alternative configuration, in accordance with a pal embodimet~ of the present im~tion;
Fig. 15 is a schematic illustration of a heating vessel for use in window cleaning apparatus, in aaordaace with a preferred embodiment of the present iaMeation;
F'ig. I6 is a schanatic illustration showing a heating wire for use in the vessel of Fig. 15, in accordance with a prefeCred embodiment of the present ion; and Figs 17A L are schematic ilhtstrations showing operation of the vessel of Fig.
15 and the apparatus in which the vessel is used, in accordance with a prefet'red embodiment of the present imrention.
DETAIZED DESCRIPTTON OF PREFERRED EMBODIMENTS
Reference is now made to Fig. 1, which is a schematic pictorial illustration shawin4g electrically poarcred window do-icing and cleaning apparatus 20 for vehicles, in accordancx with a preferred embodiment of the present irnrention, shown asstmbled for use in an automobile 22 having a windshield 24 coated with ice 26.
A healable v~sd 28 for windshield washing fluid is connected a washing flund reservoir 30 of automobile 22 and spray heads 32, which .spray the fluid onto windshield 24 when actuated by an operator 25 of the aattomobilc. The operator may actuate the apparatus ~tht~r from inside or outside automobile 22, as shows in the figure and desGn'bed fi:rther hereinbelow. Vessel 28 has an islet port 34, which receives washer fluid from reservoir 30, and an outlet port 36 through which heated fluid is discharged to spray heads 32.
The fluid is driven by a pump 40, which is ge~a~lly already present in sutoatobile 2~ for spraying unheated fluid to clean windshield 24. A battery 42 provides power to apparatus 20, and wipers 44 clean melted ice and dirt from the windshield, as is known in the art. A controller 46 regulates the operation of apparatus 20, aad optionally also controls wipers 44 in conjunction with operation of the apparatus. Other aspects and details of the apparatus are described further hereinbelow.
Fig. 2 is a schematic, partly sectional diagram showing details of vessel 28 and other elements of apparatus 20, in accordance with a preferred embodiment of the presem invention.
Vessel 28 is generally cylindrical in shape and. comprises an inner chamber 52 surrounded by an outer chamber 54. Iaaer chamber 52 is contained and defined by an inner wall 56, preferably comprising a metal such as stainless steel. Outer chamber 54 is surrounded by an outer wall 58 of the vessel, preferably comprising an insulating material, such as a plastic. A heating element 50 inside inner chamber 52 heats the fluid in vessel 28. As a result of the concentric arrangement of chambers 52 and 54, heat losses from vessel 28 are minimized, since heat lost by the hot fluid in chamber 52 is used largely to pre-heat the colder fluid in chamber 54. Since the fluid in chamber 54 is cooler, its heat losses through outer wall 58 are relatively small.
Heating element 50 preferably comprises a resistively-heated elecuicat element, which is powered by battery 42 via controller 46, in accordance with a heating sequence described further hereinbelow. Alternatively or additionally, element SO may be heated by exchange of heat with a heat source in automobile 22, such as the engine cooling fluid or exhaust. Electrical heating by battery 42 is advaatageous, however, since it allows vessel 28 to be heated rapidly even before the automobile is started. Preferably, element 50 draws approximately 400 W, which typical automobile batteries can supply easily. Moreover, vessel 28 is preferably sized so thax within about one minute or less of actuation, it is capable of heating and discharging fluid of a volume and temperature suffscient to melt ice 26. For this purpose, inner chamber 52 preferably contains about 50 ml of the fluid. It will be appreciated, however, that the principles of the present invention may similarly be applied by scaling the volume of vessel 28 and the power of element 50 to any required capacity. In particular, when apparatus 20 is used in larger vehicles, such as trucks or boars, the volume and power draw of the vessel will typically bs substantially larger than in automobile 22.
When operator 25 of vclucle 22 actuates apparatus 20, controller 46 allows current from battery 42 to flow in heating element 50, so that vessel 28 begins to heat up. Any fluid in the vessel is preferably allowed to drain out through a drain port 60, by openi~ a drain valve 62. Valve 62, like other valves used in apparatus 20, as will be described hereinbelow, preferably comprises a solenoid vatv5 of any suitable type known in the art, which is controlled by controller 46. The cornroller preferably applies a relatively high initial current to open the valve, but then reduces the to a lower level to hold the valve open. Thus, element 50 pre-heats the vessel, including particularly inner wall 56. The heat that builds up in the vessel tends to vaporize fluid remaining therein, generating p~~e~ure that forces the fluid out through pore 60, regardless of whether vessel 28 is positioned higher or Lower than reservoir 30.
Preferably, a temperature sensor 64 measures the temperature in vessel 28 sail provides feedback to controller 46.
After the vessel has reached a desired temperature, preferably with heating element SO
rea,chiag a temperature of several hundred degrees centigrade, drain valve 62 is closod and as inlet valve 66 is opened. Alternatively, the valves may simply be opened after a predetermined tiaxe has elapsed, since the presence of a residual amount of fluid at the bottom of vessel 28 will egectivdy prevent severe overheating of the vessel. Pump 40 is operated to convey an initial quantity of wasbQng fluid, preferably between 30 and 50 mI, from reservoir 30 to inlet port 34.
A ono-way valve 68 preferably prevents back flow of the fluid toward drain port 60. Aa outlet valve 74 is preferably a threo-way valve, i.e., of a type having two inlets and a single outlet ('m which fluid may also enter through the outlet and flow back to the inlets), enabling either of the inlets to be in communication with the outlet. Valve 74 is set to allow flow from outlcx port 36 to spray heads 32, and to block flow through a bypass line 76. Alternatively, separate valves may be provided for the .outlet and bypass line.
The fluid fills outer chaanber 54 and flows into inner chamber 52 through openings 70 in inner wall 56. An additional opening ?2 sear the top of wall 56 aids in pressure equa>;xation between the inner and outer chambers. Upon contact arith the hot element 50 and wall 56, the fluid is rapidly heated, causing a portion of the fluid to vaporize. The pressure of the vaporization forces the hot fluid out through outlet port 36 and spray heads 32, at an elevated temperature and pressure. Optionally, outlet valve 74 is held closed even after opining inlet valve 66, and is opened only after sufficient pressure has built up in vessel 28, either autonomously or operated by controller 46. The hot, pressurized fluid not only facilitates rapid melting of ice 26 on windshield 24, but also is capable of blowing out blockages in fluid lines between outlet port 36 and spray heads 32 that may be caused by ice or dirt.
Preferably, a ono-way valve 78 slamts outlet port 36 to ambient air so as to relieve vacuum conditions that may After the initial quantity of heated fhiid has been discharged, pump 40 and inlet valve 66 are operated to refill vessel 28. Although heating elemern 50 and wall 56 are no longer as hot as they were before the initial quatttity of the fluid was introduced into the vessel, they still retain some residual heat, facilitating rapid heating of the refilled fluid.
When the refilled fluid reaches a desired temperature and/or a#ler a predetermined period of time, it is discharged through valve 74 and spray heads 32. This process is repeated a desired number of times in sequence, untz~ an entire sequence of discharges has been completed, as described heranbelow, or until the windshield has been cleaned andlor de-iced, or until the temperature is vessel 28 drops below a predetermined minimum, or until it is interrupted by operator 25. (It is noted that under normal conditions, the temperature of the vessel will generally decrease from one quantity to the next in the sequence. If controller 46 receives an indication of an increase in the temperature, such an increase wial generally be indicative of a malfinaction, for exanapley a failure of fluid to refill the vessel, and the controller will preferably interrupt the power supplied to element 50.) The driver may they again actuate apparatus 20 and begin a new cycle of heating and fluid discharge.
Preferably, each time vessel 28 is refaled, heated fluid is discharged through the spray hands for about 3 sec, at intervals of about 5 sec or longer between fills, generally as determined by the time needed for the fluid to reach a desired temperature.
The temperature of Inter discharges in the sequence may be less than that of the initial and other earlier discharges.
Further preferably, wipers 44 are operated in cooperation with the discharge of fluid from apparatus 20, so that the wipers go on only during and shortly after the fluid discharge.
Optionally, wiper operation may be delayed, so that the wipers do not operate during the initial discharge, when ice 26 has not yet melted, but only start from the second and subsequent discharges.
After the sequence of discharges of heated fluid is completed, valves 66 and 74 are closed (relative to vessel 28), and drain valet 62 is preferably opened, so that any fluid remaining in the vessel can drain back into reservoir 30. (Pump 40 is generally not sealed against back flaw.) An upper end 61 of drain port 60 is preferably elevated relaxive to the bottom of chamber 52, so that a minimal amount of fluid will be left in vessel 28 even after draining. The vessel is than ready for rapid operation the next time apparatus 20 is acdtated.
Bypass line 76 allows unheated fluid from reservoir 30 to be pumpod directly to spray heads 32, without passing through vessel 28. Line 76 is open to the spray heads whenever valve 74, which is preferably a three-cvay valve, as noted above, is closed mlative to outlet port 36. Line 76 can be used is warm weather, when de-icing is not needed, or when a cleaning spray is needed im~m~diately, and there is not timc to heat the fluid.
Preferably, valve 74 remains open relative to line 76, so that fluid from the line is conveyed to spray h~esds 32, wheaovc~r the heating apparatus is not actuated. A ono-way valve 80 in line 76 preferably blocks any back-flow of $uid through the line.
Apparatus 20 thus provides additional window cleaning functionality for automobile 22, at relatively low cost and without interfering with gre-existing window washing capabilities.
The apparatus may either be installed as part of the window washing system in a nave automobile, or it may easily be retrofitted into an existing washing system.
Although the parts of apparatus 20 are shown in Figs. 1 and 2 as being in certain positions and orientations relative to automobile 2,2 and the washing system therein, other positions and orientations are clearly possible. For example, vessel 28 may be placed at a different angle from the orientation shaven in the figures, as Long as ports 34, 36 and GO are suitabtlr positioned and oriented in the vessel.
Although in the preferred embodiment shown in Fig. 2, apparatus 20 inchides valves 62, 66 and 74 controlling ports 60, 34 and 36 of vessel 28 in a certain fluid flow configuratior~ it will be understood that other configurations may also be eased. In particular, it is not necessary to use alI three vatvcs. For example, valves 66 and 74 may be dispensed with, along with line 76, and pump 40 used to drive and control the $uid flow through vessel 28.
Furtherrnore, although the parts of apparatus 20 are shown, for the sake of clarity, as separate units connected by tubing, in actuality at least a portion of the apparatus is preferably coiutiucted as a block, to minimize heat losses. Furthermore, in such a configuration, cold washing fluid can be made to pass near the solenoid valves, removing the heat therefrom and increasing the e9iciency of the fluid heating process. It will be appreciated that in any case, because apparatus 20 is largely closed and operates in a series of short hcat/filUdischarge cycles, any leakage or fluid loss will generally have only a minimal effect on its operation Control of apparatus 20 by controller 46 is descn'bed hereinabove as being based on feedback to the controller provided by sensor 64. This sensor is shown in Fig.
2 as being placed at the upper end of vessel 28, where it will measure the temperature either of vapor or fluid in chamber 52, depending on whether the chamber is ernpty or filled.
Controller 46 preferably tracks and monitors changes in temperature sensed by sensor 64 during heatlfll/discharge of vassol 28. If the temperawre exceeds a predetmaximum, or if temperature charges do not follow a predetermined normal profile, the controller will conclude that a malfunction has occurred, such as blockage of inlet 34 or outlet 36 or a failure of sensor 64, and will preferably interrupt operation of the apparatus and notify operator 25 by an appropriate signal.
In addition or alternative to sensor 64, there may be a temperature sensor nearer the bottom of the vessel, to measure the fluid temperature therein. Other sensors, such as a pressure sensor or pressure-stet or a fluid level sensor, may also be &xed in the vessel and provide feedback to controller 46. Further temperature sensors may also be used, inchiding a sensor 82 on an outer surface of vessel 28, a sensor 84 in reservoir 30 for measuring the temperature of fluid therein, and a sensor 86 on an outer surface of automobile 22, most preferably on windshield 24. These sensors provide inputs to controller 46, which accordingly sets parameters such as the voltage applied to element 50 and/or the lengths of time for which the elemem and fluid in vessel 28 are heated.
Preferably, the cotmoller sets the parameters so that the fluid is sprayed onto windshield 24 at a temperature high enough to melt ice 26 quickly under prevalent ambient conditions, as indicated by sensor 86, for example, but not so high (relative to the temperature of the windshield) as to create a danger of cracking the windshield or violating safety regulations in this regard. The selection of the parameters is preferably automatic, without requiring intervention by operator 25 of automobile 22, except to actuate or de-actuate apparatus 20 as desired.
Fig. 3 is a schematic illustration showing positioning of temperature sensor 86 on windshield 24, in accordance with a prefeaed embodiment of the present imrention. In order for controller 46 to ddermine accurately to what temperature the fluid should be heated, it is necessary to know the temperature of the outer surface of windshield 24. If sensor 86 is placed openly on the windshield and exposed to the sue, however, it will typically read a higher temperature than that of the transparent windshield itself. Therefore, sensor 86 is preferably covered by a reflective cover 88, thus largely neutralizing the effect of solar radiation on the temperature reading.
When operator 25 is is automobile 22, he or she actuates apparatus 20 either by means of a switch on the dashboard or by signaling controller 46 using an existing wash/wipe switch already present in the automobile. For example, the operator may press or pull the existing switch two or three times in rapid succession to turn apparatus 20 on or off In addition, as illustrated in Fig. 1, operator 25 may use an optional remote control 90 to actuate apparatus 20 before getting into automobile 22. Remote control 90 may also be used to initiate automatic operation of wipers 44, and thus to clean and de-ice windshield 24.
The remote control may be of any suitable type known in the art, including either an active device, such as a RF transmitter, or a passive device, such as an optical or infrared retrore~ector. By actuating the apparatus before getting into the automobile, the operator can reduce the length of lima spent waiting for the fluid to heat up.
Fig. 4 is a schematic block diagram illustrating the operation of controller 46 in apparatus 20, in accordance with a preferred embodiment of the present invention. Controller 46 is preferably coupled to an antenna 92, for receiving signals from remote control 90. As described hereinabove, the controller receives signals from temperature sensor 64, as well as other sensors, such as sensor 84. It also receives electrical power from battery 42 and distributes the power, preferably by means of relays (not shown), to valves 62, 66 and 74 and to pimap 40 and heating element 50.
Antenna 92 can also be used to allow wireless control of apparatus 20 when operator .
is inside the car, so that there is no need to connect additional wires and switches on the dashboard of automobile 22. Alternatively, controller 46 may be connected by wire to an operating switch and indicator lamp (not shown in the f~ures), by means of which the operator actuates apparatus 20 and is notified of its proper operation or, possibly, malfunction.
20 Before providing power to the valves, pump and heating element, controller preferably performs a self test. The test includes measurement of input voltage from battery 42 (which must preferably be at least 9 volts for a typical automobile 22 having a 12-volt battery), as well as checidag that the electrical resistance of heating eleaiGat 50 is within predetermined bounds. If any part of the self test fails, controller 46 will not allow apparatus 20 to operate, 25 and will preferably provide a maI~uaction indication to operator 25.
F~. 5 is a timing diagram illustrating a sequence 96 of heatlfill/discharge cycles of apparatus 20, in accordance with a preferred embodiment of the presem invention. Initially, as descnbed hereinabove, drain valve 62 is opened and heating element 50 is energized to pro-heat vessel 28. Valve 62 is closed, preferably aRer about IS sec. Alternatively, the drain valve may be held closed for a short period, preferably about 20 sec, so that the fluid in vessel 28 is heated to a high temperature before the valve is opened. ~ This alternative is particularly useful if controller 46 determines that one of the valves, partia~iarly inlet valve 66, is stuck and will not open, in which case the heated fluid is used to force the valve open.
Ideating continues untz'1 sensor 64 reaches a target temperature, preferably about 85oC
(dependent on the exact position of the sensor), in chamber 52, or for about 70 sec, if the temperature does not reach the target temperature. At that point, pump 40 and inlet and outlet valves 66 and 74 open, to admit and discharge the initial quantity of fluid.
The temperature in chamber 52 drops, and is subsequently repeated, preferably to about 60oC, whereupon a second quantity of the fluid is admitted and discharged. The process of repeating, fill and discharge continues for a predetermined number of cycles, or until gated by operator 25.
After the final discharge in sequence 96, drain valve 62 is opened, and heating elemtnt 50, which is energized substantially continuously throughout the sequence, remains energized for about IS sec more, in order to heat and drive out of vessel 28 as uwch as possible of any fluid rernaiaiag therein, down to the level of upper end 6I. The apparatus is then ready to begin the next sequence, when required by the user.
IS Fig. 6 is a scheamatic illustration showing an alternative configuration of apparatus 20, in accordance with a preferred embodiment of the present invention. Except as indicated hereinbelow, the parts of the apparatus shown in Fig. 6 are substantially similar or identical to those shown in Fio. 2 and described with reference thereto. This embodiment differs from that of Fig. 2 in that in Fig. 6, outlet valve 74 is eliminated, and inlrt valve 66 is a three-way valve, 24 as described hereinabove, which alternately connects inlet port 34 or bypass line 76 to pump 40. Instead of outlet valve 74, a one-way valve 98, preferably a spriu~ loaded one-way valve, prevents #luid passing through bypass lane 76 from flowing back through outlet 3 b into vessel 28 when valve 66 is open in the direction of the bypass line. Oa the other hand, when valve 66 is open in the direction of inlet port 34, the resultarn pressure in vessel 28 forces valve 98 open, 25 so that heated fluid is discharged through spray heads 32.
Referring now to Fig 7, there is seen in a sectional view a healable vessel I28 for use in apparatus 20, in accordance with an alternative embodiment of the present invention.
Although the structure of vessel 128 is somewhat different from that of vessel 28, it may be used in a substantially similar manner. Outlet port 34 may in this case also be used as a drain 30 port.
Fig. 8 ~lustratcs another healable vessel 130 of cylindrical form, in accordance with a preferred embodiment of the present invention. Advauta~eousty vessel 130 has an outer enclosure 132 made of a rigid plastic tube, forming one of two spaced-apart walls. An inner wall 134 comprises a plastic tube 136 inside a metal tube 138. Metal tube 138 is preferably made of stainless steel which, being a poor heat conductor among metals, reduces heat losses.
Plastic tubes I32 cad 136 are made of a material which has a wide temperature operating range, for example polyetherne or polyphenylene sulfide. Using a pair of end-caps 140 and I42 which are epoxy filled, tubes 132, 136 and 138 are easily held in alignment. The embodiment shown is particuZatly useful for manufacturing moderate quantities without incurring high tooling costs.
Inltt port 34 and outlet port 36 comprise nipples for the respective attachment of the ends of plastic tubes (seen generally in Figs. 1 and 2) used for cormectiag betwee~a washing fluid reservoir 30 and spray heads 32, which is preferably divided by cutting during installation of apparatus 20. Drain port 60 allows fluid to return to reservoir 30 after the apparatus has been used, as described hereinabove.
In the embodimcrrt shown in Fig. 8, heating element 50 is a combination of three electric raastance elements, which are connected in parallel. A single burnt-out element will thus allow the device to continue to ikon, though at reduced power.
Refewing now to Fig. 9, there is shown a perspective view of another heatable vessel 150 for use in apparatus 20, in accordance with a preferred embodiment of the present invention. A terminal 152 is connected imernally to a set of heating units (shown in Fig. 11), each having an outer jacket through which the washer fluid passes. The negative, or ground connection of vessel 150 is made directly to the body of the heating units mourned therein, via a bridge conaeetor 154 and a retaining band (not shown) which secures vessel 150 to automobile 22. Insulation material 156 provides the vessel with thermal insulation, typically by a lightvveia,,trt, low conductivity material.
As will be further described with reference to the figures that follow, vessel includes three separate, individual hcabng units, each located in a housing jacket through which fluid Bows from washer fluid reservoir 30 to windshield spray heads 32. By a novel artaagement of the heating units and fluid jackets, the fluid is pre-heated during flow and is re-ciradatod to obtain the maximum effective temperature when exiting as a jet from the spray heads. The heating units are electrical and designed to provide suffiaent heat capacity such that during fluid Sow in the system, a sufficierict temperature is immediately reached. Thus, the inventive design is effective in providing a washer fluid system for de-icing of windshield 24, without roquiring a long delay as with prior art systtxns based on vehicle engine heat. Unlike prior art systems, no pre-heating of the washer fluid is required, and the capacity of immediate hot washer fluid is limited only by the size of the fluid reservoir. The inventive snit uses the existing washer terhaology, hoses and power source. Because vessel 150 is designed to provide a substantially continuous flow of fluid, which is heated during flow, it will typically be capable of providing a slower flow of hot fluid onto windshield 24 than the hid 8ow rate of the bursts of hot fluid from vessel 28.
Referring now to Fig. 10, there is shown an electrical schemaaic diagrarn of the heating waits' connection in vessel 150. A single I00 watt heating unit 166 is cormected in parallel with IO two 150 watt units 152 and 164, providing a 400 W total configtxratioa This heating capacity achieves nearly instant heating of the washer fluid. In this fashion, there is no significant time delay from windshield washer system operation until exit of hot spray. This is because the heating is achieved dtuing fluid flow in the system, without changing the system flow rate and pressure. Optionally, only one or two of units 1G2, 164 and 166 may be used when a relatively IS lower temperature, and therefore less heating power, is required.
In operation, when electrical switch 168 is closed, vessel I50 operates immediately to heat the washer fluid in the system such that a hot fluid jet spray exits spray heads 32 and begins to clean windshield 24 via normal operation of wipers 44. Since the heating need not be continuous, electrical switch 168 can be an intermittem type, to periodically interrupt curxeat. A
20 corrosion resistant type of electrical switch is typically used.
Other than pressing switch I68 closed, operator 25 need not do anything fiucther, as the system operates by spraying washer fluid at approximately 50 degrees above the ambient ttmperature (or at another appropriate temperature, in accordance with operating conditions), and together with the wiper morioa, the fluid melts and cleans the windshield of ice. Within an 25 interval of only about 15 seconds, the windshield is normally cleaned and de-iced, and driving can begin. Re-freezing of liquid is very unlikely in this very short period.
Referring now to Figs. 11 and 12, there are shown, respectively, a side view and a sectional view of the internal portion of vessel 150, in accordance with a preferred embodimcrrt of the present invention. Vessel I50 contains a set of three heating units 232, 234 and 236.
30 Each of heating units 232-236 is typically provided as a resistance load heater, as shown in the schematic diagram of Fig. 10. Individual outer jackets 238, 239 and 240 are constructed around each of heating units 232-235 so that each surrounds iu own inurnal heating dement, to enable washer fluid to ~ckly absorb heat during $ow in the outer jackets 23 8-?A0.
As stated above, the h~iag waits are designed for 12-volt operation and are provided as sealed, corrosion.-resistant wants. Aitetnatively, the units may be designed to operate at 24 volts, or any other suitable DC or AC voltage. Their dimensions are so as to de$me an aaauiar Bow passaec (see Fig. 13A) between each unit and its outer jacket, of ions which enable maintenance of the desired system fluid press<ue, as set by the vehicle .
Fluid inlet pipe 34 is constructed so as to extend alongside the entire length of heating units 232-236, and is connected to outer jacket 239 of heating unit 234 at its Iowa end 244.
This construction provides a pro-hcating function, such that the washer fluid flowing in pipe 34 absorbs heat energy emitted by heating units 232-23 G before ernering omen jaclcrt 239.
The flow of washer fluid through jacket 239 causes it to be heated by heating unit 234, by absorbing heat from the heating eleau~. Once the washer fluid has reached the top of jacket 239, it $ows via a connecting tube 246 and re-enters vessel 150 at the lower cud of outer jacket IS Z40, so as to be heated during $ow thcrethmugh by heati~ unit 236. Lipon reaching the top of jacket 240, the washer fhud is again directed via a connecting tube 248 so as to ro-enter vessel 150 at the lower end of outer jacket 238.
At the top of outer jacket 238, there is connected fluid outlet pipe 36, through w~ch the washer fluid exits vessel I50 after flowing through outer jacket 238 and being heated by heatins unit 232. Thus, after the passage through outer jackets 238-240, the washer fluid is provided with the ma~dmum possible heat level before flowing to spray heads 32 mounted opposite windshield 24. Spray heads 32 may be specially designed with an adjustable angle to direct the spray at the most e$ective point on the windshield.
In Fig. 12, a cross-sectional view of vessel 1 SO is shown, taken along section lines ?aI-3~I in Fig. 1 I, revealing further construction details of heating units 232 236 and outer jackets 238-240. Fhud inlet pipe 34 and the atrarrgmQent of connecting tubes 246 and 248 is also shown. The design of units 232 Z36 and outer jackets 238 240 in close proximity to each other adds to the heat efficiency of the derma of the vessel Beat eff ciency design considerations also affect 'the choice of materials to be used in veasd 150. For o~mple, choice of copper or brass tubing for inlet tube 34 insures high heat eoaa~ivity, while tubes 246, 248 and 36 should be chosen of Iow thermal coal, matrrial, to ensure minimum heat loss. ?ubes 34 and 36 have toothed end portions for easy connection thereto. Outer jackets ?a"8-240 are also made from mateciaIs chosen for heat efflcieacy considerations, to have low thermal conductivity.
In Figs. 13A B, there are shown, respectively, a top view and a sectional side view of vessel 150, wherein the sectional view is taken along section Lines X~-~. The 5 construction of outer jackets 238-240 is shown in detail, including annular flow passage 249 defined around each of heating units 232-236, and a collection chamber 252 defined at the lower end of vessel 150.
Based on the above description, the design of vessel 150 typically features a stainless steel construction of approximately 200 mm length, with each outer Jacket having overall 10 diameter of IZ-I3 mm, and wall thiclmess of 1 mm. Heating units 232-236 are typically each 8 mm in diameter. The overall diameter of the vessel is approumately S 1 nun.
Fluid inlet pipe 34~
and outlet pipe 36 are typically corutructed of 3116 inch diameter pipe. This design assures that vessel 150 is a compact, heat efficient unit which does not limit flow rates or pressures. As w$1 be understood by those stalled in the art, various of the dimensions can be designed in 15 accordance with existing washer system designs or particular vehicle manufacturers, to maimain the nominal flow rate and pressure of the fluid flow.
As will be appreciated by those ski3led in the art, the heating of washer fluid dining its flow through the system is the main advantage of vessel 150, since the heating occurs while the fluid is moving, and not while standing. The particular flow rates and design dimensions can be 20 easily established in accordance with design techniques familiar to those skilled in the art. In addition, the choice of heating unit capacities may be increased for particular vehicles, such as flocks and buses.
Referring now to Fig. I4, there is shown an alternative installation approach for window cleaning apparatus 220, including vessel 150, in which the spray heads 32 are located on windshield wipers 44 themselves, in accordance with a preferred embodimem of the present imreation. In this arraagemcnt, spray heads 32 are connected via flexible tubes Z55-256, each of which is secured within a slot 258 provided on the underside of wipers 44.
Thus, hot spray is delivered directly to the windshield at the location at which the greatest de-icing e$ect is obtained, since the wipers 44 physically break the ice. It will be understood that wipers 44 must be operated wht~e the fluid is being sprayed from spray heads 32.
In summary, apparatus 220 of the present ittvemion can be provided as a low-cost, easily manufacnued accessory for ex~ng windshield washer/wiper systems or it can be provided in new vehicle designs. The rugged and simple design of vessel I50 makes it an attractive add-on accessory, which provides an efl'ective and quick solution to windshield icing problems, eahanci~ comfort and safety. Apparatus 220, in addition to being sirripIe and easily installed, does not complicate the vehicle manufacturer's new car assembly line, nor does it burden existing washer systems to which it is applied, in a five-minute installation process. A
manual user control existing in the vehicle is preferably used to operate the wiper fluid pump.
Fig. 15 schematically ilhxstrates a vessel 300, for use with apparatus 20 or 220, n:u:atis muta~is, in accordance with another preferred embodiment of the present invention. In vessel 300, a single jacket 312 is used to hold three separate heating elements, one of which, an elemem 304, is shown in the figure extending longitudinally through the vessel. Jacket 3I2 preferably comprises steel or other material generally cylindrical is shape and having two opposed ends. At one end, there is a cap 320 defining a chamber 322, having a volume preferably between 24 and 40 mI, depending on the size of the vehicle in which it is installed.
Inlet port 34 and outlet port 36 provide communication into the chamber, although as will be described hertinbelow, at certain times washing fluid may flow in through the outlet and out .
through the inlet port.
Fig. 16 is a schematic, sectional illustration of a wire 310 from which element 304 is wound, in accordance with a preferred embodiment of the present invention.
Wire 3I0 is substantially circular in cross section, and is formed of a magnesium oxide core 306 surrounded by a cerunic sleeve or coating 308. Preferably, the core has a diameter in the range of 0.07-0.14 mm. For example, for standard cars, a 500 W unit is suffaent, and wire 310 may have a 0.07 mm core. For larger vehicles, such as trucks, a 0.14 mm core may be necessary to generate up to 700 W of brat. Sleeve or coating 308 is preferably deposited by a standard laser process using a high-density ceramic powder, as is known in the art.
Preferably, coating 308 has a thickness of about 0.10 mm The two ends 3I4 of element 304 are provided with magnesium oxide connectors, which are coupled to be powered via controller 46 as described hereinabove. In this embodiment, controller 46 preferably senses whether the motor of automobile 22 is operating, for example by detecting an AC ripple on the voltage from battery 42, and does not allow power to be provided to vessel 300 unless the motor is rumiing, so as to avoid discharging the battery.
Cap 320 is Shed with an epoxy or other material capable of withstanding high temperatures up to 700oC. rn a preferred embodiment, controller 46 is contained in the cap, as shown is Fig. 15. rn addition, ports 34 and 36 are provided with valves 366 and 374. These valves are preferably made of a silicone n~bbet and are capable of operating at high temperatures such as ?00oC. The valves are coupled to controller 46 by wires (not shown in the figure) to indicate the positions of the valves and to control their operation. Valves of this kind are available front U.S. Plastics oflxma, Ohio.
F'~s. 17A-L are schematic diagcaa~s showing states of vessel 300 and valves 366 and 374 illustrative of the operation of the vessel, in accordance with a preferred embodiment of the present invention. Prior to operation, chamber 322 in vessel 300 is empty, and the valves are open. Operator 2S gets in automobile 22, starts the engine and, in order to de-ice windshield 24, operates pump 40. The pump generates a pressure at inlet port 34. The pressure is sensed by valve 366, which automatically closes without say conunand from cot~roller 46. This position is shows in Fig. I7A.
Nab, valve 366 wakes up controller 46 to initiate a de-icing process. The first step of this process is to heat up element 304 by connecting battery 42 across element 304. In the absence of water in chamber 322, the chamber heats quickly to a very high temperature. The temper~.ure of the chamber is monitored by a sensor, such as sensor 64, in the chaanbar. When the sensor reaches a preset level, preferably about 608oC, controller 46 opens valve 366 and after a short period closes valve 374, thus allowing washing fluid to flow into chamber 322 (Fig. I7B).
Next, the controller monitors the temperature of the fluid in the chamber.
When this temperature reaches about 58oC, the controller disconnects element 304 from the battery and warts for the driver to activate pump 40 again (F'ig. 17C). When the pump is activated again, the pressure is sensed by valve 366 and causes the valve to open. When the valve opens, controller 46 senses this action and causes valve 374 to open as well. The result is that hot water flows from chamber 322 through outlet 36 to windshield 24 (Fig. I7D).
The initial a~rge is actually a mi~hue of hot water and steam, which causes any ice on spray heads 32 to melt and to clear the no2zles of the spray heads. Steam may also be generated in the position of Fig.
17A due to some water IeR over in chamber 322 from the previous operation.
ARer pump 40 stops the pressure pulse, valves 366 and 374 stay open, altowiug water to flow back from outlet 36 through chamber 322 and out again through inlet 34 to reservoir 30 (Fig. 17E). Whey this ba~clc flow stops, as sassed by valve 374, this latter valve closes (Fig.
17F). Controller 46 then forces valve 366 to close as well (Fig. 17G). Thus, an amount o~
fluid is trapped in chamber 322, and element 304 starts heating the fluid Whey the fluid reaches 58oC, element 304 is turned off, and vessel 300 waits for the next operation of pump 40 Wig. I7F~. This operation is sensed (Fig. 1'717, as described above, causing the whole process to repeat again (Fig. 17J).
Controller 46 times the iirterval between the last back-flow and the next pressure surge from pump 40. If over a minute is measured, and no pressure is sensed, co~roIler 46 purges chamber 322 by Srst closing valves 366 and 374 (Fig. 17ICJ and activating element 304, to raise the fluid in the chamber to a very high temperature. Then the valves open (Fig. 17L), allowing the fluid to escape as steam. Controller 46 then powers down and waits for the next operation.
A similar process may be applied to vessel 150 (shown in Figs. 9-13B).
Tt will be appreaated that the preferred embodiments described above are cited by way of example, and the full scope of the invention is lid only by the claims.
It is aoa obpect of the print invention to provide improved epparedns for deaning a vehicle window.
According to the present invention there is provided ~ for deaaing a window of a vehicle a vessel having an inlet through which a washiu~g fluid is received from a reservoir and an owlet trough which the fluid is dis~srgod for deaning die window. The gPpmratus also ia~udes a hewing elammt Eor lreebag the fluid in the vessel, a tempesat~c saasx which senses a range of ternperetwcea in the vessel arrd a controller for c~rotliag flow of the fluid IO through the vessel. The ooatroller is i~ ekc~ricat oo~oumnaicarion with tax tomperaetra seasoar ao sutomaticstly and iatarmit~ntty releases. qusof the Said through the oat a desiirod teainpearat~u~e is raspoa to the temp~attaes s~sad by the sear $ pref~ed e~mbodiac:e~s of tlx iaves~o~ a vessel. is provid~od for $
,oo~sshlag did bsgoat the $e:id i~ discd~ocg~ed reward a. ofla . 8~o~rs tba did is IS ihttoduced into the v~ t3x vessel is pfd, pa~rabTy bg passing alt el~ciml u>:r~
a big in the vesse3 for about ome 'or less. Whm plug is comnpleted, the Said is allowed late the vessel and is bested ~r contact tl:~w~h, leading to an increase is pr~a~ iat the vessel due to vaporizstioa of a portion of the .. The $uid is sbrn fed at a desa~ed ~e and pr~ae so as to Win. andlo~c derice~ tire 20 window Ahhe~ t3tc pr~ao~ of the viesset draws only a modem c>earical iaptu from the eddde batoacy, it .a qusr~y of Lot fluid to be g~cr~ed Soc aea~g tlx ~~i~daar before stag tlu v~icda more raptly titan is any pzscdcad window deanoang sys»an kaarova is the art. Moreover, the pressure grated by vapoQiz:daa of the $uid beige to deer ZS ice or other btod~s that may base iti Zub~g or ao~tes though whch tba t3oid is spayed onto the ~ov~adoW It is also anted that sprspiag the toted fluid ~ the wiaddw's exterior smrfsce a~Ctively defogs its iataior senfaee, as ~a~.
Ia soma prafared embodimenots of the prramt iaventie~ p$er as im~tal qust~ty of tiu $uid has base hotbed and discbasgod from tlu vesad, a ~rther qyn~y is fed into the 30 v~a~el and dy bested. 4s~ce the futlxer qoan:ity 1~ ra desired tmaparatur~
it too is discharged, padera~y s8er 8 delay ~ sets. This process copes Sot repeated lxat/disGhanrge cycles, until the window has been cornpictety deaned and de-iced.
3a pr~xably, the ~ca~tcar~C cyc~ are ti~xed in a sequarcc whose para~natars~ such as discharge duoratioa. aad in~erva3s be~rovaca disc~aoc~os, are vaznod is a~coac~taa~ca wilt tm~ratur~ of't?ic v~ic~e and the 8irid.
Xt w4Ii be tmd~tood tact the te~cm "vehicle" as uxd is the coatexc of the pact pit apps and is the claims aan rifer to say type of whxiod ve~cle l~riag ovir~dorovs, such as as atzcomebile oor tracts, as well at to ~a boat or aizplane. Poao~r~ the z~
'~rindow."
ahhough typbcaB~r reg to- the windahieZd of a vehicle, caa refer to at:y traasparant including side and rear windows and outer mirrors, as well as covers of headliglus and the like.
In addition, whenever the term "cIeanirig" is used in the present application and in the claims in reference to an action involving spraying heated fluid on a window, the term will be understood to comprehend de-icing, as well. Those skilled in the art ~n'lI appreciated that the priaaples of the present invention may he adapted for cleaning and de-icing other surfaces, inesudiag internal windows and mirrors, far exataple, as well as for supplied heated water and fluid for other purposes.
There is therefore provided, in accordance with a preferred embodiment of the presem imrention, apparatus for cleaning a window of a vehicle, including:
20 a vessel, having an inlet through which a washing fluid is received from a reservoir and an outlet through which the fluid is discharged for cleaning the window; and a heating element for heating the fluid in the vessel, which elenneut preheats the vessel before the washing fluid is received therein, whereby at least an initial quantity of the fluid is rapidly heated and discharged from the vessel.
Preferably, the vessel is at least partly drained of fluid held therein before the element preheats the vessel, wherein the vessel includes a drain valve, actuated is cooperation with operation of the heating element, through which the vessel is at least partly drained. Preferably, the drain valve includes a one-way valve. Further preferably, the fluid drains into the reservoir, substantially irrespective of the height of the reservoir relative to the vessel.
Preferably, the apparatus includes a pump, which comreys the fluid from the reservoir to the vessel after the element preheats the vessel, wherein the pump and the reservoir are preferably part of a pre-existing window cleaning system is the vehicle, into which the vessel and beating element are retrofitted. Alternatively, the entire apparatus may be produced as an integral unit, including the pump. Preferably, the rapid heatir~ of the initial quantity of the $uid causes the fluid to be discharged at a pressure substantially higher than a pressure generated by the pump at the iulet of the vessel.
Preferably, the apparatus includes are or more valves, which regulate passage of fluid through the vessel responsive to operation of the heatiao clement, wherein the one or more valves open and close is cooperation with operation of the heating element.
Preferably, the one or more valves include a solenoid valve or alternatively, a hydraulic, pneumatic or vacuum-operated valve. At least one of the one or more valves is preferably fixed to the inlet of the vessel or, alternatively or additionally, to the outlet of the vessel, wherein the at least one valve _ CA 02565312 2006-11-14 fixed to the outlet opetrs responsive to a pressure increase in the vessel, due to comact beta~n the fluid and the preheated vessel Ia a preferred embodiment, the apparatus includes one or more temperature sensors, which generate signals responsive to an operating temperature of the apparatus, and a S controller, which receives the signals and regulates discharge of the $uid from the vessel responsive thereto. Preferably, after the initial quantity of the fluid is discharged, one or more additional quan:ities of fhud are refilled into the vessel and discharged therefrom intermittently, responsive to the temperature signals, wherein the quantities are discharged when the ternperaturc signals indicate that the temperature of the $uid in the vessel is above a predeterniined threshold, and the discharge is interrupted whsn the temperature of the fluid falls below the threshold. Alternatively or additionally, the quantities are controlled according to a predetermined timing sequence, which is selected responsive to the temperature signals, and the temperature threshold may vary among the quantities is the sequence.
In aaotba prefee:ed embodiment, the controller analyzes the signals to detect a malfunction of the apparatus and interrupts operation of the heating elemart whey the malfunction is detected.
Preferably, at least one of the one or morc temperature sensors is insade the vessel. The at least one sensor is preferably substantially immersed in the fluid in the vessel. Alternatively, the at least one sensor is positioned so as to be substantially out of the fluid in the vessel while the heating element preheats the vessel. Preferably, operation of the heating element is interrupted when the temperature inside the vessel exceeds a predetermined ma~mum.
In a preferred embodiment, at least one of the one or mare temperature sensors is faced on an outer surface of the vessel. Additiaaally or alternatively, at least one of the one or more temperature sensors is fixed to the reservoir or on an outer surface of the vehicle, most preferably on an outer surface of the window to be cleaned, covered by an at least partially re$ective cover, so as to substantially neutralize the effect of solar radiation thereon.
Preferably, the fluid in the vessel is heated to a temperature which is varied responsive to the signals generated by the at least one sensor feed on the outer sutFace of the vehicle, or otherwise responsive to a temperature outside the vehicle.
Preferably, the vessel 'racludes as inner compartment communicating with the outlet, is which compartment the ~iag element is positioned, and an outer compartment, generally surrounding the inner compartment, com~nicating with the inlet. Preferably, the vessel includes an insulating outer envelope substantially surrounding the outer compartment and a wall between the inner and outer compartments, which is preheated by the heating element.
Alternatively, the outer compartment is surrounding by one or more additional fluid compartments, extcmal thereto.
S Preferably, the apparatus includes a pressure relief valve.
Further preferably, the apparatus includes a bypass line, bypassing the vessel, through which the fluid is conveyed to clean the window without heating the fluid, wherein when cleaning of the window is required while the element is preheating the vessel, the fluid is diverted through the bypass line. Preferably, an operator of the vehicle selects whether the IO heating apparatus is to be actuated, such that when the apparatus is de-actuated, fluid is conveyed through the bypass. Further preferably, the apparatus automatically switches between conveying the fluid through the vessel and through the bypass, responsive to a heating cycle of the vessel. When fluid is not available from the vessel, unheated fluid is, preferably, automatically conveyed through the bypass line.
15 xn a preferred embodiment, the apparatus includes a remote input device, which is actuated by a user of the vehicle to initiate preheating of the vessel lxforo starting the vehicle.
Preferably, the heating element includes a resistive heating wire.
Alternatively or additionally, the heating element conveys heat from a heat source in the vehicle to the fluid in the vessel.
20 There is also provided, in accordance with a preferred embodiment of the present invention, apparatus for cleaning a window of a vehicle, including:
a vessel, having an inlet through which a washing fluid is received from a reservoir and an outlet through which the fluid is discharged for cleaning the window;
a heating element for heating the fluid in the vessel;
25 a temperature sensor, which senses a temperature in the vessel; and a valve for controlling flow of the fluid through the vessel, which intermittently releases quantities of the fluid through the outlet at a desired temperature, responsive to the temperature sensed by the sensor.
Preferably, a windshield wiper is activated intermittently to clean the window responsive 30 to the intermitxem release of the fluid.
Preferably, the apparatus includes a controller, which regulator the iatezmitteat release of the fluid according to a given timing sequence, preferably a predetermined or programmable sequence, whereon the timing sequence is varied responsive to an ambient temperature in the vehicle or, alternatively or additionally, to a temperature of as outer surface of the window.
Preferably, an initial quantity of the $uid is released ax a substantially higher pressure thaw subsequent quantities.
There is further provided, in accordance with a preferred embodiment of the present invention, a method for cleaning a window of a vehicle using a washing $uid, including:
preheating a vessel;
introducing a quantity of the fluid into the preheated vessel, whereby the temperature and pressure of the fluid are elevated; and discharging the fluid onto the window at the elevated tempacature and pressure.
Preferably, the vessel isof fluid before preheating the vessel.
Further prektably, introduciang the fluid includes pumping the fluid into the vessel at a pump pressure, wherein the elevated pressure at which the $uid is discharged is substaatialty Beater than the pump pressure.
In a preferred embodiment, the method includes measuring a temperature of the $uid, wherein discharging the $uid includes controlling the $uid discharge responsive to the temperature measurement. Additionally or alternatively, a temperature of an outer surface of the vehicle is measured, wherein discharging the fluid includes controlling the fluid discharge responsive to the tempe<ahue of the outer surface.
There is nnoreover provided, in accordance with a preferred embodiment of the present invention, a method for cleaning a window of a vehicle using a washing $uid, including repeating a plurality of times in sequence the steps of.
heating a quantity of the fluid;
monitoring a temperature of the quantity of the fluid; and discharging the quantity when a predetermined condition on the heating of the $uid is satisfied.
preferably, the predetermined condition is satisf ed when the temperature of the quanfrty of the $uid reaches a selected level. Alternatively or additionally, the predetermined condition is satisfied when a predetermined period of time has dapsed since begimaing the heating.
There is fiuthermore provided, in accordance with a preferred embodiment of the pr~eat ion, vehicle windshield de-icing apparatus inclirdiag: a plurality of individual heating units; and a mufti jacketed housing wherein each jacket surrounds one of the heating units, the jackets being interco~eeted by fluid conduits, inchiding an inlet and outlet port, the housing being connected at the inlet port to a windshield washer fluid source and at the outlet port to a windshield spray head, the heating units hang operated to heat the v~ashar fluid during flow to the windshield spray head, the heated sprayed fluid providing a windshield de-icing effect.
There is additionally provided, in accordance with a preferred embodiment of the present invention, an clectricalIy powered windshield de-icing device for vehicles, including a healable container for windshield washing said connectable between a washing fluid reservoir and a spray heads opposite the windshield, and provided with an inlet port sad an outlet port for the fluid, and having an elecuic heater element disposed inside the healable container, the rernainir~, liquid capacity of the heatable container not exceeding 300 ml, the heater element being connectable to the vehicle battery and being sized to heat the fluid contained in the healable eomainer to de-icing temperature rxrithin no more than one minute of actuation.
The present im~ention will be more fully understood from the following detaiied 1 S description of the preferred embodiments thereoiz taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRA'oVIINGS
Fig. 1 is a schematic, pictorial illustration showing apparatus for cleaning a windshield of an automobile with heated washing fluid, in acwrdance with a preferred embodiment of the presern imreation;
Fig. 2 is a schematic diagram showing details of the cleaning apparatus of Fig. 1, in accordance with a prefezrod embodiment of the present invention;
Fig. 3 is a schematic illustration showing a temperature sensor on the windshield of the automobile of Fig. 1, in accordance with a preferred embodiment of the present invention;
Fig. 4 is a schematic block diagram illustrating the functions of an electronic controller in the apparatus ofFig. 1, in accordance with a preferred embodiment ofthe present invention;
Fig. 5 is a timing diagram illustrating operation of the apparatus of Fig. 1, is accordance with a preferred enzbodimetn of the present imientioa;
Fig. 6 is a schematic diagram showing details of windshield cleaning apparatus, in accordance with another preferred embodiment of the present invention;
Fig. 7 is a sections! view of a healable vessel for use in windshield cleaning apparatus, in accordance with a preferred anbodimeat of the present imrention;
Fig. 8 is a sectional view of a healable vessel for use in windshield cleaning apparatus, in accordance with another preferred embodiment of the present mention;
Fig. 9 is a perspective view of a heatable vessel for use in held cleaning apparatus, in accordance with still another preferred embodiment of the present invention;
Fig. 10 is as electrical schematic diagram shoaring the connection of heating units in the vessel of Fig. 9, in accordance with a preferred embodim~t of the present invention;
Fig, 1 l is a side view of an internal portion of the vessel of Fig. 10, in accordance with a preferred embodinnart of the presont invention;
Fig. 12 is a cross-sectional view of the vessel of Fig. 11, taken along line ~I I~I;
Figs. 13A and 13B arc, respectively, top and sectional side views of the vessel of Fig.
I 1, the sectional view taken along line ~-X~;
Fig. 14 is a schematic pictorial illustration showing window cleaning apparatus in an alternative configuration, in accordance with a pal embodimet~ of the present im~tion;
Fig. 15 is a schematic illustration of a heating vessel for use in window cleaning apparatus, in aaordaace with a preferred embodiment of the present iaMeation;
F'ig. I6 is a schanatic illustration showing a heating wire for use in the vessel of Fig. 15, in accordance with a prefeCred embodiment of the present ion; and Figs 17A L are schematic ilhtstrations showing operation of the vessel of Fig.
15 and the apparatus in which the vessel is used, in accordance with a prefet'red embodiment of the present imrention.
DETAIZED DESCRIPTTON OF PREFERRED EMBODIMENTS
Reference is now made to Fig. 1, which is a schematic pictorial illustration shawin4g electrically poarcred window do-icing and cleaning apparatus 20 for vehicles, in accordancx with a preferred embodiment of the present irnrention, shown asstmbled for use in an automobile 22 having a windshield 24 coated with ice 26.
A healable v~sd 28 for windshield washing fluid is connected a washing flund reservoir 30 of automobile 22 and spray heads 32, which .spray the fluid onto windshield 24 when actuated by an operator 25 of the aattomobilc. The operator may actuate the apparatus ~tht~r from inside or outside automobile 22, as shows in the figure and desGn'bed fi:rther hereinbelow. Vessel 28 has an islet port 34, which receives washer fluid from reservoir 30, and an outlet port 36 through which heated fluid is discharged to spray heads 32.
The fluid is driven by a pump 40, which is ge~a~lly already present in sutoatobile 2~ for spraying unheated fluid to clean windshield 24. A battery 42 provides power to apparatus 20, and wipers 44 clean melted ice and dirt from the windshield, as is known in the art. A controller 46 regulates the operation of apparatus 20, aad optionally also controls wipers 44 in conjunction with operation of the apparatus. Other aspects and details of the apparatus are described further hereinbelow.
Fig. 2 is a schematic, partly sectional diagram showing details of vessel 28 and other elements of apparatus 20, in accordance with a preferred embodiment of the presem invention.
Vessel 28 is generally cylindrical in shape and. comprises an inner chamber 52 surrounded by an outer chamber 54. Iaaer chamber 52 is contained and defined by an inner wall 56, preferably comprising a metal such as stainless steel. Outer chamber 54 is surrounded by an outer wall 58 of the vessel, preferably comprising an insulating material, such as a plastic. A heating element 50 inside inner chamber 52 heats the fluid in vessel 28. As a result of the concentric arrangement of chambers 52 and 54, heat losses from vessel 28 are minimized, since heat lost by the hot fluid in chamber 52 is used largely to pre-heat the colder fluid in chamber 54. Since the fluid in chamber 54 is cooler, its heat losses through outer wall 58 are relatively small.
Heating element 50 preferably comprises a resistively-heated elecuicat element, which is powered by battery 42 via controller 46, in accordance with a heating sequence described further hereinbelow. Alternatively or additionally, element SO may be heated by exchange of heat with a heat source in automobile 22, such as the engine cooling fluid or exhaust. Electrical heating by battery 42 is advaatageous, however, since it allows vessel 28 to be heated rapidly even before the automobile is started. Preferably, element 50 draws approximately 400 W, which typical automobile batteries can supply easily. Moreover, vessel 28 is preferably sized so thax within about one minute or less of actuation, it is capable of heating and discharging fluid of a volume and temperature suffscient to melt ice 26. For this purpose, inner chamber 52 preferably contains about 50 ml of the fluid. It will be appreciated, however, that the principles of the present invention may similarly be applied by scaling the volume of vessel 28 and the power of element 50 to any required capacity. In particular, when apparatus 20 is used in larger vehicles, such as trucks or boars, the volume and power draw of the vessel will typically bs substantially larger than in automobile 22.
When operator 25 of vclucle 22 actuates apparatus 20, controller 46 allows current from battery 42 to flow in heating element 50, so that vessel 28 begins to heat up. Any fluid in the vessel is preferably allowed to drain out through a drain port 60, by openi~ a drain valve 62. Valve 62, like other valves used in apparatus 20, as will be described hereinbelow, preferably comprises a solenoid vatv5 of any suitable type known in the art, which is controlled by controller 46. The cornroller preferably applies a relatively high initial current to open the valve, but then reduces the to a lower level to hold the valve open. Thus, element 50 pre-heats the vessel, including particularly inner wall 56. The heat that builds up in the vessel tends to vaporize fluid remaining therein, generating p~~e~ure that forces the fluid out through pore 60, regardless of whether vessel 28 is positioned higher or Lower than reservoir 30.
Preferably, a temperature sensor 64 measures the temperature in vessel 28 sail provides feedback to controller 46.
After the vessel has reached a desired temperature, preferably with heating element SO
rea,chiag a temperature of several hundred degrees centigrade, drain valve 62 is closod and as inlet valve 66 is opened. Alternatively, the valves may simply be opened after a predetermined tiaxe has elapsed, since the presence of a residual amount of fluid at the bottom of vessel 28 will egectivdy prevent severe overheating of the vessel. Pump 40 is operated to convey an initial quantity of wasbQng fluid, preferably between 30 and 50 mI, from reservoir 30 to inlet port 34.
A ono-way valve 68 preferably prevents back flow of the fluid toward drain port 60. Aa outlet valve 74 is preferably a threo-way valve, i.e., of a type having two inlets and a single outlet ('m which fluid may also enter through the outlet and flow back to the inlets), enabling either of the inlets to be in communication with the outlet. Valve 74 is set to allow flow from outlcx port 36 to spray heads 32, and to block flow through a bypass line 76. Alternatively, separate valves may be provided for the .outlet and bypass line.
The fluid fills outer chaanber 54 and flows into inner chamber 52 through openings 70 in inner wall 56. An additional opening ?2 sear the top of wall 56 aids in pressure equa>;xation between the inner and outer chambers. Upon contact arith the hot element 50 and wall 56, the fluid is rapidly heated, causing a portion of the fluid to vaporize. The pressure of the vaporization forces the hot fluid out through outlet port 36 and spray heads 32, at an elevated temperature and pressure. Optionally, outlet valve 74 is held closed even after opining inlet valve 66, and is opened only after sufficient pressure has built up in vessel 28, either autonomously or operated by controller 46. The hot, pressurized fluid not only facilitates rapid melting of ice 26 on windshield 24, but also is capable of blowing out blockages in fluid lines between outlet port 36 and spray heads 32 that may be caused by ice or dirt.
Preferably, a ono-way valve 78 slamts outlet port 36 to ambient air so as to relieve vacuum conditions that may After the initial quantity of heated fhiid has been discharged, pump 40 and inlet valve 66 are operated to refill vessel 28. Although heating elemern 50 and wall 56 are no longer as hot as they were before the initial quatttity of the fluid was introduced into the vessel, they still retain some residual heat, facilitating rapid heating of the refilled fluid.
When the refilled fluid reaches a desired temperature and/or a#ler a predetermined period of time, it is discharged through valve 74 and spray heads 32. This process is repeated a desired number of times in sequence, untz~ an entire sequence of discharges has been completed, as described heranbelow, or until the windshield has been cleaned andlor de-iced, or until the temperature is vessel 28 drops below a predetermined minimum, or until it is interrupted by operator 25. (It is noted that under normal conditions, the temperature of the vessel will generally decrease from one quantity to the next in the sequence. If controller 46 receives an indication of an increase in the temperature, such an increase wial generally be indicative of a malfinaction, for exanapley a failure of fluid to refill the vessel, and the controller will preferably interrupt the power supplied to element 50.) The driver may they again actuate apparatus 20 and begin a new cycle of heating and fluid discharge.
Preferably, each time vessel 28 is refaled, heated fluid is discharged through the spray hands for about 3 sec, at intervals of about 5 sec or longer between fills, generally as determined by the time needed for the fluid to reach a desired temperature.
The temperature of Inter discharges in the sequence may be less than that of the initial and other earlier discharges.
Further preferably, wipers 44 are operated in cooperation with the discharge of fluid from apparatus 20, so that the wipers go on only during and shortly after the fluid discharge.
Optionally, wiper operation may be delayed, so that the wipers do not operate during the initial discharge, when ice 26 has not yet melted, but only start from the second and subsequent discharges.
After the sequence of discharges of heated fluid is completed, valves 66 and 74 are closed (relative to vessel 28), and drain valet 62 is preferably opened, so that any fluid remaining in the vessel can drain back into reservoir 30. (Pump 40 is generally not sealed against back flaw.) An upper end 61 of drain port 60 is preferably elevated relaxive to the bottom of chamber 52, so that a minimal amount of fluid will be left in vessel 28 even after draining. The vessel is than ready for rapid operation the next time apparatus 20 is acdtated.
Bypass line 76 allows unheated fluid from reservoir 30 to be pumpod directly to spray heads 32, without passing through vessel 28. Line 76 is open to the spray heads whenever valve 74, which is preferably a three-cvay valve, as noted above, is closed mlative to outlet port 36. Line 76 can be used is warm weather, when de-icing is not needed, or when a cleaning spray is needed im~m~diately, and there is not timc to heat the fluid.
Preferably, valve 74 remains open relative to line 76, so that fluid from the line is conveyed to spray h~esds 32, wheaovc~r the heating apparatus is not actuated. A ono-way valve 80 in line 76 preferably blocks any back-flow of $uid through the line.
Apparatus 20 thus provides additional window cleaning functionality for automobile 22, at relatively low cost and without interfering with gre-existing window washing capabilities.
The apparatus may either be installed as part of the window washing system in a nave automobile, or it may easily be retrofitted into an existing washing system.
Although the parts of apparatus 20 are shown in Figs. 1 and 2 as being in certain positions and orientations relative to automobile 2,2 and the washing system therein, other positions and orientations are clearly possible. For example, vessel 28 may be placed at a different angle from the orientation shaven in the figures, as Long as ports 34, 36 and GO are suitabtlr positioned and oriented in the vessel.
Although in the preferred embodiment shown in Fig. 2, apparatus 20 inchides valves 62, 66 and 74 controlling ports 60, 34 and 36 of vessel 28 in a certain fluid flow configuratior~ it will be understood that other configurations may also be eased. In particular, it is not necessary to use alI three vatvcs. For example, valves 66 and 74 may be dispensed with, along with line 76, and pump 40 used to drive and control the $uid flow through vessel 28.
Furtherrnore, although the parts of apparatus 20 are shown, for the sake of clarity, as separate units connected by tubing, in actuality at least a portion of the apparatus is preferably coiutiucted as a block, to minimize heat losses. Furthermore, in such a configuration, cold washing fluid can be made to pass near the solenoid valves, removing the heat therefrom and increasing the e9iciency of the fluid heating process. It will be appreciated that in any case, because apparatus 20 is largely closed and operates in a series of short hcat/filUdischarge cycles, any leakage or fluid loss will generally have only a minimal effect on its operation Control of apparatus 20 by controller 46 is descn'bed hereinabove as being based on feedback to the controller provided by sensor 64. This sensor is shown in Fig.
2 as being placed at the upper end of vessel 28, where it will measure the temperature either of vapor or fluid in chamber 52, depending on whether the chamber is ernpty or filled.
Controller 46 preferably tracks and monitors changes in temperature sensed by sensor 64 during heatlfll/discharge of vassol 28. If the temperawre exceeds a predetmaximum, or if temperature charges do not follow a predetermined normal profile, the controller will conclude that a malfunction has occurred, such as blockage of inlet 34 or outlet 36 or a failure of sensor 64, and will preferably interrupt operation of the apparatus and notify operator 25 by an appropriate signal.
In addition or alternative to sensor 64, there may be a temperature sensor nearer the bottom of the vessel, to measure the fluid temperature therein. Other sensors, such as a pressure sensor or pressure-stet or a fluid level sensor, may also be &xed in the vessel and provide feedback to controller 46. Further temperature sensors may also be used, inchiding a sensor 82 on an outer surface of vessel 28, a sensor 84 in reservoir 30 for measuring the temperature of fluid therein, and a sensor 86 on an outer surface of automobile 22, most preferably on windshield 24. These sensors provide inputs to controller 46, which accordingly sets parameters such as the voltage applied to element 50 and/or the lengths of time for which the elemem and fluid in vessel 28 are heated.
Preferably, the cotmoller sets the parameters so that the fluid is sprayed onto windshield 24 at a temperature high enough to melt ice 26 quickly under prevalent ambient conditions, as indicated by sensor 86, for example, but not so high (relative to the temperature of the windshield) as to create a danger of cracking the windshield or violating safety regulations in this regard. The selection of the parameters is preferably automatic, without requiring intervention by operator 25 of automobile 22, except to actuate or de-actuate apparatus 20 as desired.
Fig. 3 is a schematic illustration showing positioning of temperature sensor 86 on windshield 24, in accordance with a prefeaed embodiment of the present imrention. In order for controller 46 to ddermine accurately to what temperature the fluid should be heated, it is necessary to know the temperature of the outer surface of windshield 24. If sensor 86 is placed openly on the windshield and exposed to the sue, however, it will typically read a higher temperature than that of the transparent windshield itself. Therefore, sensor 86 is preferably covered by a reflective cover 88, thus largely neutralizing the effect of solar radiation on the temperature reading.
When operator 25 is is automobile 22, he or she actuates apparatus 20 either by means of a switch on the dashboard or by signaling controller 46 using an existing wash/wipe switch already present in the automobile. For example, the operator may press or pull the existing switch two or three times in rapid succession to turn apparatus 20 on or off In addition, as illustrated in Fig. 1, operator 25 may use an optional remote control 90 to actuate apparatus 20 before getting into automobile 22. Remote control 90 may also be used to initiate automatic operation of wipers 44, and thus to clean and de-ice windshield 24.
The remote control may be of any suitable type known in the art, including either an active device, such as a RF transmitter, or a passive device, such as an optical or infrared retrore~ector. By actuating the apparatus before getting into the automobile, the operator can reduce the length of lima spent waiting for the fluid to heat up.
Fig. 4 is a schematic block diagram illustrating the operation of controller 46 in apparatus 20, in accordance with a preferred embodiment of the present invention. Controller 46 is preferably coupled to an antenna 92, for receiving signals from remote control 90. As described hereinabove, the controller receives signals from temperature sensor 64, as well as other sensors, such as sensor 84. It also receives electrical power from battery 42 and distributes the power, preferably by means of relays (not shown), to valves 62, 66 and 74 and to pimap 40 and heating element 50.
Antenna 92 can also be used to allow wireless control of apparatus 20 when operator .
is inside the car, so that there is no need to connect additional wires and switches on the dashboard of automobile 22. Alternatively, controller 46 may be connected by wire to an operating switch and indicator lamp (not shown in the f~ures), by means of which the operator actuates apparatus 20 and is notified of its proper operation or, possibly, malfunction.
20 Before providing power to the valves, pump and heating element, controller preferably performs a self test. The test includes measurement of input voltage from battery 42 (which must preferably be at least 9 volts for a typical automobile 22 having a 12-volt battery), as well as checidag that the electrical resistance of heating eleaiGat 50 is within predetermined bounds. If any part of the self test fails, controller 46 will not allow apparatus 20 to operate, 25 and will preferably provide a maI~uaction indication to operator 25.
F~. 5 is a timing diagram illustrating a sequence 96 of heatlfill/discharge cycles of apparatus 20, in accordance with a preferred embodiment of the presem invention. Initially, as descnbed hereinabove, drain valve 62 is opened and heating element 50 is energized to pro-heat vessel 28. Valve 62 is closed, preferably aRer about IS sec. Alternatively, the drain valve may be held closed for a short period, preferably about 20 sec, so that the fluid in vessel 28 is heated to a high temperature before the valve is opened. ~ This alternative is particularly useful if controller 46 determines that one of the valves, partia~iarly inlet valve 66, is stuck and will not open, in which case the heated fluid is used to force the valve open.
Ideating continues untz'1 sensor 64 reaches a target temperature, preferably about 85oC
(dependent on the exact position of the sensor), in chamber 52, or for about 70 sec, if the temperature does not reach the target temperature. At that point, pump 40 and inlet and outlet valves 66 and 74 open, to admit and discharge the initial quantity of fluid.
The temperature in chamber 52 drops, and is subsequently repeated, preferably to about 60oC, whereupon a second quantity of the fluid is admitted and discharged. The process of repeating, fill and discharge continues for a predetermined number of cycles, or until gated by operator 25.
After the final discharge in sequence 96, drain valve 62 is opened, and heating elemtnt 50, which is energized substantially continuously throughout the sequence, remains energized for about IS sec more, in order to heat and drive out of vessel 28 as uwch as possible of any fluid rernaiaiag therein, down to the level of upper end 6I. The apparatus is then ready to begin the next sequence, when required by the user.
IS Fig. 6 is a scheamatic illustration showing an alternative configuration of apparatus 20, in accordance with a preferred embodiment of the present invention. Except as indicated hereinbelow, the parts of the apparatus shown in Fig. 6 are substantially similar or identical to those shown in Fio. 2 and described with reference thereto. This embodiment differs from that of Fig. 2 in that in Fig. 6, outlet valve 74 is eliminated, and inlrt valve 66 is a three-way valve, 24 as described hereinabove, which alternately connects inlet port 34 or bypass line 76 to pump 40. Instead of outlet valve 74, a one-way valve 98, preferably a spriu~ loaded one-way valve, prevents #luid passing through bypass lane 76 from flowing back through outlet 3 b into vessel 28 when valve 66 is open in the direction of the bypass line. Oa the other hand, when valve 66 is open in the direction of inlet port 34, the resultarn pressure in vessel 28 forces valve 98 open, 25 so that heated fluid is discharged through spray heads 32.
Referring now to Fig 7, there is seen in a sectional view a healable vessel I28 for use in apparatus 20, in accordance with an alternative embodiment of the present invention.
Although the structure of vessel 128 is somewhat different from that of vessel 28, it may be used in a substantially similar manner. Outlet port 34 may in this case also be used as a drain 30 port.
Fig. 8 ~lustratcs another healable vessel 130 of cylindrical form, in accordance with a preferred embodiment of the present invention. Advauta~eousty vessel 130 has an outer enclosure 132 made of a rigid plastic tube, forming one of two spaced-apart walls. An inner wall 134 comprises a plastic tube 136 inside a metal tube 138. Metal tube 138 is preferably made of stainless steel which, being a poor heat conductor among metals, reduces heat losses.
Plastic tubes I32 cad 136 are made of a material which has a wide temperature operating range, for example polyetherne or polyphenylene sulfide. Using a pair of end-caps 140 and I42 which are epoxy filled, tubes 132, 136 and 138 are easily held in alignment. The embodiment shown is particuZatly useful for manufacturing moderate quantities without incurring high tooling costs.
Inltt port 34 and outlet port 36 comprise nipples for the respective attachment of the ends of plastic tubes (seen generally in Figs. 1 and 2) used for cormectiag betwee~a washing fluid reservoir 30 and spray heads 32, which is preferably divided by cutting during installation of apparatus 20. Drain port 60 allows fluid to return to reservoir 30 after the apparatus has been used, as described hereinabove.
In the embodimcrrt shown in Fig. 8, heating element 50 is a combination of three electric raastance elements, which are connected in parallel. A single burnt-out element will thus allow the device to continue to ikon, though at reduced power.
Refewing now to Fig. 9, there is shown a perspective view of another heatable vessel 150 for use in apparatus 20, in accordance with a preferred embodiment of the present invention. A terminal 152 is connected imernally to a set of heating units (shown in Fig. 11), each having an outer jacket through which the washer fluid passes. The negative, or ground connection of vessel 150 is made directly to the body of the heating units mourned therein, via a bridge conaeetor 154 and a retaining band (not shown) which secures vessel 150 to automobile 22. Insulation material 156 provides the vessel with thermal insulation, typically by a lightvveia,,trt, low conductivity material.
As will be further described with reference to the figures that follow, vessel includes three separate, individual hcabng units, each located in a housing jacket through which fluid Bows from washer fluid reservoir 30 to windshield spray heads 32. By a novel artaagement of the heating units and fluid jackets, the fluid is pre-heated during flow and is re-ciradatod to obtain the maximum effective temperature when exiting as a jet from the spray heads. The heating units are electrical and designed to provide suffiaent heat capacity such that during fluid Sow in the system, a sufficierict temperature is immediately reached. Thus, the inventive design is effective in providing a washer fluid system for de-icing of windshield 24, without roquiring a long delay as with prior art systtxns based on vehicle engine heat. Unlike prior art systems, no pre-heating of the washer fluid is required, and the capacity of immediate hot washer fluid is limited only by the size of the fluid reservoir. The inventive snit uses the existing washer terhaology, hoses and power source. Because vessel 150 is designed to provide a substantially continuous flow of fluid, which is heated during flow, it will typically be capable of providing a slower flow of hot fluid onto windshield 24 than the hid 8ow rate of the bursts of hot fluid from vessel 28.
Referring now to Fig. 10, there is shown an electrical schemaaic diagrarn of the heating waits' connection in vessel 150. A single I00 watt heating unit 166 is cormected in parallel with IO two 150 watt units 152 and 164, providing a 400 W total configtxratioa This heating capacity achieves nearly instant heating of the washer fluid. In this fashion, there is no significant time delay from windshield washer system operation until exit of hot spray. This is because the heating is achieved dtuing fluid flow in the system, without changing the system flow rate and pressure. Optionally, only one or two of units 1G2, 164 and 166 may be used when a relatively IS lower temperature, and therefore less heating power, is required.
In operation, when electrical switch 168 is closed, vessel I50 operates immediately to heat the washer fluid in the system such that a hot fluid jet spray exits spray heads 32 and begins to clean windshield 24 via normal operation of wipers 44. Since the heating need not be continuous, electrical switch 168 can be an intermittem type, to periodically interrupt curxeat. A
20 corrosion resistant type of electrical switch is typically used.
Other than pressing switch I68 closed, operator 25 need not do anything fiucther, as the system operates by spraying washer fluid at approximately 50 degrees above the ambient ttmperature (or at another appropriate temperature, in accordance with operating conditions), and together with the wiper morioa, the fluid melts and cleans the windshield of ice. Within an 25 interval of only about 15 seconds, the windshield is normally cleaned and de-iced, and driving can begin. Re-freezing of liquid is very unlikely in this very short period.
Referring now to Figs. 11 and 12, there are shown, respectively, a side view and a sectional view of the internal portion of vessel 150, in accordance with a preferred embodimcrrt of the present invention. Vessel I50 contains a set of three heating units 232, 234 and 236.
30 Each of heating units 232-236 is typically provided as a resistance load heater, as shown in the schematic diagram of Fig. 10. Individual outer jackets 238, 239 and 240 are constructed around each of heating units 232-235 so that each surrounds iu own inurnal heating dement, to enable washer fluid to ~ckly absorb heat during $ow in the outer jackets 23 8-?A0.
As stated above, the h~iag waits are designed for 12-volt operation and are provided as sealed, corrosion.-resistant wants. Aitetnatively, the units may be designed to operate at 24 volts, or any other suitable DC or AC voltage. Their dimensions are so as to de$me an aaauiar Bow passaec (see Fig. 13A) between each unit and its outer jacket, of ions which enable maintenance of the desired system fluid press<ue, as set by the vehicle .
Fluid inlet pipe 34 is constructed so as to extend alongside the entire length of heating units 232-236, and is connected to outer jacket 239 of heating unit 234 at its Iowa end 244.
This construction provides a pro-hcating function, such that the washer fluid flowing in pipe 34 absorbs heat energy emitted by heating units 232-23 G before ernering omen jaclcrt 239.
The flow of washer fluid through jacket 239 causes it to be heated by heating unit 234, by absorbing heat from the heating eleau~. Once the washer fluid has reached the top of jacket 239, it $ows via a connecting tube 246 and re-enters vessel 150 at the lower cud of outer jacket IS Z40, so as to be heated during $ow thcrethmugh by heati~ unit 236. Lipon reaching the top of jacket 240, the washer fhud is again directed via a connecting tube 248 so as to ro-enter vessel 150 at the lower end of outer jacket 238.
At the top of outer jacket 238, there is connected fluid outlet pipe 36, through w~ch the washer fluid exits vessel I50 after flowing through outer jacket 238 and being heated by heatins unit 232. Thus, after the passage through outer jackets 238-240, the washer fluid is provided with the ma~dmum possible heat level before flowing to spray heads 32 mounted opposite windshield 24. Spray heads 32 may be specially designed with an adjustable angle to direct the spray at the most e$ective point on the windshield.
In Fig. 12, a cross-sectional view of vessel 1 SO is shown, taken along section lines ?aI-3~I in Fig. 1 I, revealing further construction details of heating units 232 236 and outer jackets 238-240. Fhud inlet pipe 34 and the atrarrgmQent of connecting tubes 246 and 248 is also shown. The design of units 232 Z36 and outer jackets 238 240 in close proximity to each other adds to the heat efficiency of the derma of the vessel Beat eff ciency design considerations also affect 'the choice of materials to be used in veasd 150. For o~mple, choice of copper or brass tubing for inlet tube 34 insures high heat eoaa~ivity, while tubes 246, 248 and 36 should be chosen of Iow thermal coal, matrrial, to ensure minimum heat loss. ?ubes 34 and 36 have toothed end portions for easy connection thereto. Outer jackets ?a"8-240 are also made from mateciaIs chosen for heat efflcieacy considerations, to have low thermal conductivity.
In Figs. 13A B, there are shown, respectively, a top view and a sectional side view of vessel 150, wherein the sectional view is taken along section Lines X~-~. The 5 construction of outer jackets 238-240 is shown in detail, including annular flow passage 249 defined around each of heating units 232-236, and a collection chamber 252 defined at the lower end of vessel 150.
Based on the above description, the design of vessel 150 typically features a stainless steel construction of approximately 200 mm length, with each outer Jacket having overall 10 diameter of IZ-I3 mm, and wall thiclmess of 1 mm. Heating units 232-236 are typically each 8 mm in diameter. The overall diameter of the vessel is approumately S 1 nun.
Fluid inlet pipe 34~
and outlet pipe 36 are typically corutructed of 3116 inch diameter pipe. This design assures that vessel 150 is a compact, heat efficient unit which does not limit flow rates or pressures. As w$1 be understood by those stalled in the art, various of the dimensions can be designed in 15 accordance with existing washer system designs or particular vehicle manufacturers, to maimain the nominal flow rate and pressure of the fluid flow.
As will be appreciated by those ski3led in the art, the heating of washer fluid dining its flow through the system is the main advantage of vessel 150, since the heating occurs while the fluid is moving, and not while standing. The particular flow rates and design dimensions can be 20 easily established in accordance with design techniques familiar to those skilled in the art. In addition, the choice of heating unit capacities may be increased for particular vehicles, such as flocks and buses.
Referring now to Fig. I4, there is shown an alternative installation approach for window cleaning apparatus 220, including vessel 150, in which the spray heads 32 are located on windshield wipers 44 themselves, in accordance with a preferred embodimem of the present imreation. In this arraagemcnt, spray heads 32 are connected via flexible tubes Z55-256, each of which is secured within a slot 258 provided on the underside of wipers 44.
Thus, hot spray is delivered directly to the windshield at the location at which the greatest de-icing e$ect is obtained, since the wipers 44 physically break the ice. It will be understood that wipers 44 must be operated wht~e the fluid is being sprayed from spray heads 32.
In summary, apparatus 220 of the present ittvemion can be provided as a low-cost, easily manufacnued accessory for ex~ng windshield washer/wiper systems or it can be provided in new vehicle designs. The rugged and simple design of vessel I50 makes it an attractive add-on accessory, which provides an efl'ective and quick solution to windshield icing problems, eahanci~ comfort and safety. Apparatus 220, in addition to being sirripIe and easily installed, does not complicate the vehicle manufacturer's new car assembly line, nor does it burden existing washer systems to which it is applied, in a five-minute installation process. A
manual user control existing in the vehicle is preferably used to operate the wiper fluid pump.
Fig. 15 schematically ilhxstrates a vessel 300, for use with apparatus 20 or 220, n:u:atis muta~is, in accordance with another preferred embodiment of the present invention. In vessel 300, a single jacket 312 is used to hold three separate heating elements, one of which, an elemem 304, is shown in the figure extending longitudinally through the vessel. Jacket 3I2 preferably comprises steel or other material generally cylindrical is shape and having two opposed ends. At one end, there is a cap 320 defining a chamber 322, having a volume preferably between 24 and 40 mI, depending on the size of the vehicle in which it is installed.
Inlet port 34 and outlet port 36 provide communication into the chamber, although as will be described hertinbelow, at certain times washing fluid may flow in through the outlet and out .
through the inlet port.
Fig. 16 is a schematic, sectional illustration of a wire 310 from which element 304 is wound, in accordance with a preferred embodiment of the present invention.
Wire 3I0 is substantially circular in cross section, and is formed of a magnesium oxide core 306 surrounded by a cerunic sleeve or coating 308. Preferably, the core has a diameter in the range of 0.07-0.14 mm. For example, for standard cars, a 500 W unit is suffaent, and wire 310 may have a 0.07 mm core. For larger vehicles, such as trucks, a 0.14 mm core may be necessary to generate up to 700 W of brat. Sleeve or coating 308 is preferably deposited by a standard laser process using a high-density ceramic powder, as is known in the art.
Preferably, coating 308 has a thickness of about 0.10 mm The two ends 3I4 of element 304 are provided with magnesium oxide connectors, which are coupled to be powered via controller 46 as described hereinabove. In this embodiment, controller 46 preferably senses whether the motor of automobile 22 is operating, for example by detecting an AC ripple on the voltage from battery 42, and does not allow power to be provided to vessel 300 unless the motor is rumiing, so as to avoid discharging the battery.
Cap 320 is Shed with an epoxy or other material capable of withstanding high temperatures up to 700oC. rn a preferred embodiment, controller 46 is contained in the cap, as shown is Fig. 15. rn addition, ports 34 and 36 are provided with valves 366 and 374. These valves are preferably made of a silicone n~bbet and are capable of operating at high temperatures such as ?00oC. The valves are coupled to controller 46 by wires (not shown in the figure) to indicate the positions of the valves and to control their operation. Valves of this kind are available front U.S. Plastics oflxma, Ohio.
F'~s. 17A-L are schematic diagcaa~s showing states of vessel 300 and valves 366 and 374 illustrative of the operation of the vessel, in accordance with a preferred embodiment of the present invention. Prior to operation, chamber 322 in vessel 300 is empty, and the valves are open. Operator 2S gets in automobile 22, starts the engine and, in order to de-ice windshield 24, operates pump 40. The pump generates a pressure at inlet port 34. The pressure is sensed by valve 366, which automatically closes without say conunand from cot~roller 46. This position is shows in Fig. I7A.
Nab, valve 366 wakes up controller 46 to initiate a de-icing process. The first step of this process is to heat up element 304 by connecting battery 42 across element 304. In the absence of water in chamber 322, the chamber heats quickly to a very high temperature. The temper~.ure of the chamber is monitored by a sensor, such as sensor 64, in the chaanbar. When the sensor reaches a preset level, preferably about 608oC, controller 46 opens valve 366 and after a short period closes valve 374, thus allowing washing fluid to flow into chamber 322 (Fig. I7B).
Next, the controller monitors the temperature of the fluid in the chamber.
When this temperature reaches about 58oC, the controller disconnects element 304 from the battery and warts for the driver to activate pump 40 again (F'ig. 17C). When the pump is activated again, the pressure is sensed by valve 366 and causes the valve to open. When the valve opens, controller 46 senses this action and causes valve 374 to open as well. The result is that hot water flows from chamber 322 through outlet 36 to windshield 24 (Fig. I7D).
The initial a~rge is actually a mi~hue of hot water and steam, which causes any ice on spray heads 32 to melt and to clear the no2zles of the spray heads. Steam may also be generated in the position of Fig.
17A due to some water IeR over in chamber 322 from the previous operation.
ARer pump 40 stops the pressure pulse, valves 366 and 374 stay open, altowiug water to flow back from outlet 36 through chamber 322 and out again through inlet 34 to reservoir 30 (Fig. 17E). Whey this ba~clc flow stops, as sassed by valve 374, this latter valve closes (Fig.
17F). Controller 46 then forces valve 366 to close as well (Fig. 17G). Thus, an amount o~
fluid is trapped in chamber 322, and element 304 starts heating the fluid Whey the fluid reaches 58oC, element 304 is turned off, and vessel 300 waits for the next operation of pump 40 Wig. I7F~. This operation is sensed (Fig. 1'717, as described above, causing the whole process to repeat again (Fig. 17J).
Controller 46 times the iirterval between the last back-flow and the next pressure surge from pump 40. If over a minute is measured, and no pressure is sensed, co~roIler 46 purges chamber 322 by Srst closing valves 366 and 374 (Fig. 17ICJ and activating element 304, to raise the fluid in the chamber to a very high temperature. Then the valves open (Fig. 17L), allowing the fluid to escape as steam. Controller 46 then powers down and waits for the next operation.
A similar process may be applied to vessel 150 (shown in Figs. 9-13B).
Tt will be appreaated that the preferred embodiments described above are cited by way of example, and the full scope of the invention is lid only by the claims.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for cleaning a window of a vehicle, comprising:
a vessel, having an inlet through which a washing fluid may be received from a reservoir and an outlet through which the fluid may be discharged to at least one spray head for cleaning the window;
a heating element for heating the fluid in the vessel;
a controller for controlling flow of the fluid; and a bypass through which fluid may be selectably conveyed from said reservoir to said at least one spray head, said controller being operative to automatically convey fluid through said bypass when cleaning of the window is required while fluid is not available from said vessel.
a vessel, having an inlet through which a washing fluid may be received from a reservoir and an outlet through which the fluid may be discharged to at least one spray head for cleaning the window;
a heating element for heating the fluid in the vessel;
a controller for controlling flow of the fluid; and a bypass through which fluid may be selectably conveyed from said reservoir to said at least one spray head, said controller being operative to automatically convey fluid through said bypass when cleaning of the window is required while fluid is not available from said vessel.
2. Apparatus according to claim 1, and further comprising at least one temperature sensor, which generates at least one signal responsive to an operating temperature of the apparatus and wherein said controller receives said at least one signal and regulates discharge of the fluid from the vessel responsive thereto.
3. Apparatus according to claim 1, and wherein said controller is operative to intermittently release quantities of the fluid through the outlet.
4. Apparatus according to claim 3, and further comprising a windshield wiper which is activated intermittently to clean the window responsive to the intermittent release of the fluid.
5. Apparatus according to claim 3, wherein said controller regulates the intermittent release of the fluid according to a given timing sequence.
6. Apparatus according to claim 5, wherein the timing sequence is varied responsive to an ambient temperature in the vehicle.
7. Apparatus according to claim 5, wherein the timing sequence is varied responsive to a temperature of an outer surface of the window.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2626431A CA2626431A1 (en) | 1997-06-24 | 1998-06-24 | Windshield de-icing |
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IL121159 | 1997-06-24 | ||
| IL12115997A IL121159A0 (en) | 1997-06-24 | 1997-06-24 | Vehicle windshield de-icing apparatus and method |
| US7673098P | 1998-03-04 | 1998-03-04 | |
| US60/076,730 | 1998-03-04 | ||
| IL12429998A IL124299A0 (en) | 1998-05-03 | 1998-05-03 | Vehicle windscreen de-icing device |
| IL124299 | 1998-05-03 | ||
| CA002294103A CA2294103C (en) | 1997-06-24 | 1998-06-24 | Windshield de-icing |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002294103A Division CA2294103C (en) | 1997-06-24 | 1998-06-24 | Windshield de-icing |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2626431A Division CA2626431A1 (en) | 1997-06-24 | 1998-06-24 | Windshield de-icing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2565312A1 CA2565312A1 (en) | 1998-12-30 |
| CA2565312C true CA2565312C (en) | 2008-04-29 |
Family
ID=37545839
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002565312A Expired - Fee Related CA2565312C (en) | 1997-06-24 | 1998-06-24 | Windshield de-icing |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2565312C (en) |
-
1998
- 1998-06-24 CA CA002565312A patent/CA2565312C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2565312A1 (en) | 1998-12-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20140625 |