US2435003A - System of deicing for aircraft, vessels, etc. - Google Patents

Description

Jan. 27,-1948. w. c. HASSELHO RN SYSTEM OF DEICING FOR AIRCRAFT, VESSELS,

ETC. 4

2 Sheets-Sheet'l Filed Dec. 6, 1943 R m n u p E U P a m R P m m w 3 1 f0 WINDSHIELD I INVENTOR. walk? 6 flasselfwrnr,

"Hill H w. c. HASSELHORN Filed Dec. 6, 1943 INF- H H SYSTEM DEICING FOR AIRCRAFT, VESSELS, ETC.

Jan. 27, 1948.

, INVENTOR. ZZ/allfer flfihsielfiam. 60 61 Patented Jan. 27, 1948 SYSTEM OF DEICING FOR AIRCRAFT, VESSELS, ETC.

Walter C. Hasselhorn, Chicago, Ill., assignor to Cook Electric Company, Chicago, 111., a corporation of Illinois Application December 6, 1943, Serial No. 512,999

18 Claims. (Cl. 244-134) This invention relates to de-icing systems adapted particularly to the delivery of a deicing solution to various locations on aircraft, vessels or wherever the prevention of ice or frost formation is desirable.

An object of the invention is to provide a deicing system embodying certain novel features both in construction and operation that provides new and useful results in a device of this type. Among other things may be mentioned the low power consumption and the efficient operation of the system to maintain a steady supply of a de-icing solution to one or more locations and to measure the fluid so supplied. Although the broad concept of the invention is not limited in application to the kind of power used, in its narrower aspects the invention novelly provides an electric control circuit for the pumping units employed. The pumping units may also be electrically operated when desired and the current impulses of the control circuit used to control the operation of the pumping units. A further novel feature of the invention resides in the actuator employed. This actuator may be designed to operate the pumping units intermittently, which effects energization of the various units but deenergizes each unit before energizing the next unit. A power cut-off is operated by the actuator so that the feed is limited to the stroke of each pump. In this manner, the over-heating of the pumping units and an unnecessary drain on the battery are prevented.

More specifically, this novel type of control circuit embodies certain control characteristics particularly adapting the circuit to the control of this system disclosed. These control characteristics include controlling the duration and frequency of the current impulses produced by the circuit so that the actuator may be made to operate a pumping unit for each current impulse, the pumping unit remaining operated only for the period of the impulses and the time interval between these impulses controlling the interval between operations of these pumping units. Thus, a selector device that can readily be adjusted to vary the time interval between current impulses, may be used to control the rate of supply of each pumping unit. Although it is not necessary, the period or duration of each current impulse may be limited so that a relay operating the actuator can remain energized only long enough to allow each pumping unit as it operates to make a full stroke.

Other objects and advantages of the invention will be apparent from the following description when taken in connection with the accompanying drawings, which form a part hereof:

In the drawings:

Figure 1 is a diagrammatic layout of a deicing system embodying the invention;

Fig. 2 is a wiring diagram of the same;

Fig. 3 is a longitudinalsectional view of one of the pumping units.

Fig. 4 is a top view of the actuator; and

Fig. 5 is a side view of the actuator.

Referring to the drawings, the de-icing system herein disclosed includes a control panel I, which may be located in the operators compartment, an electronic timer 2, a source of de-icing solution 3 and a series of pumping units 4, 5 and 6 discharging their output to a number of locations, which, if an airplane, may comprise the propellers, carburetors, Windshields, wings, etc. It will be understood at the outset that the number of pumping units may vary and that more than one pumping unit may be used to supply a single location. These pumping units as well as the electronic timer equipment and solution supply may be located in any convenient place and not necessarily in the operators compartment. This is decidedly advantageous in the case of aircraft because it does not burden the pilots cabin with additional controls.

Control panel I includes a number of switches I, 8 and 9 adapted to be inserted in the respective circuits of pumping units 4, 5 and 6 for selectively cutting in or out any one of these pumping units.

In this way, it is not necessary to supply the deicing solution to all the locations when the system is operating. Control panel I also includes a selector switch In which will be more fully described hereinafter. It functions to control the frequency of the current impulses of a, control circuit so as to predetermine the number of strokes per minute of the pumping units.

The construction of the pumping units is shown in Fig. 3. The motor for each unit may comprise a solenoid ll suitably mounted within housing I2 having end sections l3 and I4 and an intermediate section 15. Intermediate section l5 encases solenoid ll, while end section [3 comprises a pressure dome having a pressure chamber I6 and inlet and outlet valves I1 and 18. A piston 20 is disposed in a chamber 2| separated from pressure chamber l6 by a partition 22 and from the solenoid II by a partition 23. Nipples 24 in which the valve bodies 25 are threadedly disposed are carried in partition 22 and are sealed at 26 to prevent the leakage of the de-icing solution from the pressure chamber H5 at this point about each nipple. Valve bodies 25 extend through the casing of the pressure dome and are likewise sealed at 21 to prevent leakage from pressure chamber l6. Partition 22 is attached by screws 28 to housing l2 while the dome housing is attached to this partition by a sealing connection 29 that prevents leaka e at this point.

Piston 20 of each pumping unit may comprise a spring bellows 30 which will return to normal 32, which may be connected to. a. pistonrod. 33; attached at its outer end to core 34 of solenoid.

When the solenoid is energized, this core.34e is drawn inwardly to compress bellows-piston 30 and force the de-icing solution within the chamber of this piston through the passage IQ of the outlet valve body 25 into the pressure chamber l6. During this time, inlet valve I1 is closed by;-

being seated as shown in Fig. 3, and outlet valve I8 is held in the position shown to allow the fluid to flow through, side passages 35' into pressure chamber l6 and also through outlet. passage 36. The timer control 2 to be hereinafter described in detail is designed to limit the flow of current through the circuit of solenoid II to the working stroke of core 34 so that when it reaches the end of this stroke, the solenoidwill be de-energized and the spring resiliency of the bellows 30 will return the bellows to its expanded position to draw on another charge of fiuidinto the piston chamber, and also to return the core 34 to its original position. Current may befed to-the winding of solenoid II by wire31 andreturnby a grounded connection, if so desired.

Pressure chamber |6 may be allowed to retain a small amount of air therein so that a steady stream of fluid may be fedthroughoutlet passage 36 to connection 38 of the pump leading to the location where the fluid is tobe supplied to prevent frost or ice formation and to remove the same if it has already accumulated. The design of the pumping unit is simple and; inexpensive. The unit is small, and hence, it occupies'very little space. It can be readily replaced byreleasing two supporting brackets .39anddisconnecting two nipple joints at the inlet and outlet connections. Consequently, if one of the units should become disabled, it can readily be replaced, even in flight. The compactnessof the parts and .the smallnes in size permit spares to.-be carried in the tool kit for the purpose of permitting-such ready replacement.

Actuator 40 for controlling the current flow to these solenoids of'the pumping-units-is-shown in Figs. 4 and 5. It comprises a sequence relay 4| and a plurality of cams 42, 43=and 44, one for each pumping unit. Each cam isprovidedwith one or more risers 45adap-tedto=close operating switche 46 connected in the respective-circuits of the pumping units. Armature-41 f sequence relay 4| is preferably pivoted at 485'and it carries a spring pawl 49 at 50. A toothed sprocket fixed to cam shaft 52 so as to cause shaft 52 to rotate with the rotation of the sprocket, is arranged to turn in clockwise direction only. Opposite rotation is preventedby-a detent spring53. As armature 41 is attracted upon energizationof the coil of relay 4|, pawl 49 is moved to the left to turn sprocket 5| and consequently the shaft 52.- When this coil is de-energized, spring 54- will return armature 41 to its original position, thereby moving pawl 49 forwardly again to engage the next tooth of sprocket 5|.

It will be noted that eachoperating'switch 46 of the pumping units comprises two contact springs 55 and 56, the lower contact spring 56' being provided with a button 51. As the-relay4| i energized and the pawl49-is-actuated to turn shaft 52, the riser 45 of one of the cams 42*; or

44 willv engagev and lift one of the buttons 51 to close the contacts of the contact springs 55 and 56 of one of the operating switches 46 and thereby close the particular circuit of the pumping unit to be operated. To efiect this operation after. the operating switch 46 is closed, a power switch 66 is also closed but only for the period current issupplied to sequence relay 4|.

Thispower. switch 60 comprises two contact springs: 6| and 62 suitably supported upon the frame structure of relay 4| as are the operating switches". A- lever 63 secured to armature 41 andmovable therewith is adapted to press contact spring 62 into circuit closing position with contact spring 6|. The power circuit is thereby closed and power is supplied to the operating switch 46 that may be closed'at the time. This power switch 60" may be connected in multiple with the operating switches 46' so that closing ofv any one of the. latter and closing the power switch 60 will supply, current to the circuit of the pumping unit in which the closed operating switch is connected. In this connection, it will be noted that power switch 66 will be opened as soon as. the current fiowthrough the coil of relay 4| ceases. This is accomplished by the movement of armature 41 by means of spring 54 to its original position and the consequent movement of lever 63. to a position breaking the circuit closing relation between thecontact springs 6| and 62,

Thetime control circuit heretofore designated as the-electronictimer 2 is illustrated inFig. 2. It may comprise two vacuum tubes 66 and 66, condensers 61 and 68, resistances 69, 16 and 1|, a control relay. 12 and a selector resistor "also termed a selector. switch I0. The vacuum tube circuit is so arranged that. when the control circult is closed, condenser 61 starts-to'draw a charging current. This, current passes through resist ance. 69, andthe' selector resistor; 13 biases tube 65, whichpreventscurrent from passing-therethrough. Whencondenser: 61 has become nearly charged. so that its; charging; currentno longer maintains avoltage .above. cutI-off, tube 65. begins to. pass current and condenser- 61 discharges. This operates control relay'n-andat'. the same time charges condenser 66';

The charging current for condenser 68- in-passing through resistance 1| biases tube 66 and-prevents-itfrompassing current. A's'condenser 66 approaches-a full charge, the current drops to a point whereitno longer produces sufficient voltage to prevent the passage of current through tube 66; When this value is-reached, the current passing through .tube 66 discharges condenser" 66 and'charges condenser 61, thus startingthe-cycle once again.

By changing the resistance in series-with condenser 61 by means ofthe selector resistor 13, which may be manually operated, the time required to charge this condenser 61 is varied. Since this time represents the off time or" the time betweenstrokes of the pumping units, the number of strokes per minute can be controlled by changing-this resistance. Resistance. 1| controls the time thatcontrol relay 1! remains operated and may be so. chosen, as to capacity that control relay 12" remains energized just long enough-to allow the'cores'34of solenoids H to make a full stroke.

It is apparentfrom Fig. 2 that controlrelay'12 may beadvantageously usedto, operate sequence relay 4|. Sequence relay 4|jmaybe in thepower. circuit ofthe pumping units as illustrated, but

it will be understood that a different arrangement of the parts may be provided as long as the same result is obtained. The control relay I2 is in the timer control circuit and the period the current flows through its coil will be controlled by resistance 1 l, and, as disclosed in the preferred embodiment of the invention illustrated herein, this resistance "H is selected so that it will permit the current to flow through the coil of the control relay 12 long enough for the pumping units to effect a forward working stroke. It will be observed that resistance H may be changed to vary this period of current flow so that pumping units of different strokes or capacities may be readily used or replaced for those in service if a change should be desirable.

It is also possible to vary the period between the impulses of the control circuit by changing the time required to charge condenser 61. As previously explained, this is accomplished by manually operating the selector switch It so as to vary the resistance placed in the circuit by this switch. Switch It! may be disposed upon panel I, and therefore, it, as well as switches l, 3 and 9, may be made readily accessible to the pilot by placing panel I in the cabin. Also, any number of pumping units may be used by use of switches I, 8 and 9, and the number of strokes each shall make per minute can be controlled from this panel I.

Actuator 40 functions to effect intermittent actuation of the pumping units 4, 5 and 6 although it is readily apparent that more than one unit may operate at one time by having risers 45 on cams 42, 43 and 44 differently disposed. Cam 42 is shown as provided with two risers 45 so as to effect two strokes of the pumping unit, which it controls, during each cycle of operation. The arrangement of the cam risers can obviously be changed even to the extent of having one of the pumping units in continuous operation, while the others may operate less frequently. Using power switch 60 does not require actuation of the sequence relay 4| to de-energize a pump circuit. The operating switch 46 of the particular pump circuit energized will remain closed and not open until the next operation of the relay 68. This pump circuit will be broken however by the opening of this power switch 60 as soon as the current ceases to flow through the relay coil on each operation. The flow of current is thus accurately controlled and is made to correspond to the period of the current impulses produced by the control circuit.

From the foregoing description, it will readily be observed that a novel system of supplying a de-icing solution to one or more locations has been disclosed and that it incorporates certain novel features producing exceptional useful results in this field.

An advantage obviously resides in the fact that only one pumping unit is made to work at a time so that the source of power will not be taxed beyond the demand of a single pumping unit at any one time. This is important in the use of a deicing system when applied to moving vehicles and particularly to airplanes, which are limited in the equipment weight that they may carry and should not carry more batteries than may be necessary. Moreover, the parts-may be compactly arranged and simply assembled as a complete accessory for mounting. For example, the wiring comprising ten in number may be neatly encased in a small conduit I5 leading from panel I to the electronic timer control 2, this conduit I5 joining a conduit '16 containing 13 wires and continuing as conduit the pump motor to be used. If the stroke of the motor is to be increased to increase the stroke of the pump piston, resistance H may be accordingly changed. On the other hand, simple manipulation of resistor switch ill on panel I will change the number of strokes per minute of the pumping units in operation. Various other features will be apparent.

Without further elaboration, the foregoing will so fully explain the gist of my invention that others may, by applying current knowledge, .readily adapt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to me by the following claims.

I claim:

1. A de-icing system for aircraft, vessels, or the like, comprising a plurality of pumps adapted to be intermittently operated, mechanism for operating said pumps, said mechanism comprising an electrically operated actuator having means for de-energizing one pump before energizing the next pump, an electric timing circuit for said actuator, said circuit including means for controlling the period of current impulses for said actuator and means for controlling the period between said current impulses.

' 2. A de-icing system for aircraft, vessels, or the like, comprising a plurality of pumps adapted to be intermittently operated, mechanism for operating said pumps, said mechanism comprising an electrically operated actuator having means for de-energizing one pump before energizing the next pump, an electric timing circuit for said actuator, said circuit including means for predetermining the duration of current impulses effectil'lg operation of said actuator,

3. A de-icing system for aircraft, vessels, or the like, comprising a plurality of pumps adapted to be intermittently operated, mechanism for operating said pumps, said mechanism comprising an electrically operated actuator having means for de-energizing one pump before energizing the next pump, an electric timing circuit for said actuator, said circuit including means for predetermining the frequency of current impulses effecting operation of said actuator.

4. A de-icing systemfor aircraft, vessels, or the like, comprising a plurality of pumps adapted to be intermittently operated, mechanism for operating said pumps, said mechanism comprising an electrically operated actuator for said pumps, an electric timing circuit for said actuator, said circuit including a control relay for operating said actuator and means for controlling current impulses energizing said control relay.

5. A de-icing system for aircraft, vessels, or the like, comprising a plurality of pumps, mechanism for operating said pumps, said mechanism comprising an electrically operated actuator for said pumps, an electric timing circuit for said actuator, said circuit including a resistance control for determining the frequency of operation of 'eachipumppand-means for-selectively cutting"out :onecr more pumps without disabling the operation of the other pumps.

6. A de-icing system for aircrait;vessels,::or;the :likegcomprising a pressure chambenforreceiv'ing :and holding a 'deicing-:solution underpressure, rpumpingimeansfor supplyingsaid'solution tosald chamber, mechanism for operating saidzpumping means, said mechanism comprising-an electrically :operated actuator, an electronic timing circuit, said circuit including a thermionic :device with a control grid. supplying currentimpulsessadapted -to effect operation of said=actuator,and means'in said circuit for :predetermining the durati'on o'f :each current impulse.

'7. VA de-icing system for aircraft, vesselsgor the like, comprising aifluid-supply chamber, pumping means for supplying a de-icing solution to-said :supply chamber, mechanism "for-operating said pumping means, said mechanism comprising an electrically operated actuator, an electronic timing-circuit, said circuit including a thermionic "device with a control grid supplying current 1mpulses adaptedto effect operation of said actuator, and means in said circuit for predetermining Ymomrimeansitoactuate -'the1period.between said current-impulses.

8. A de-icing system for=aircraft,-vessels,*or the like, comprising a plurality of electrically oper- :ated pumps,'switch means for closing the respective circuits .of said pumps when energized, an L actuator for selectively operating :said switch .means to effect intermittent ,operation of 'said pumps, a relay for operating said .actuator and a timingcircuit to energize said relay.

pumps.

14. 3A .zde-icing system f or aircraft, vessels, or *thetlike,comprisingaaplurality of-pumps-edapted to::he iintennittentlyoperated, mechanism for 0D- -er.ating1said pumps, said mechanism comprising 315 an.a'ctuator havingmeans for -de-energiz'ing one pump before energizing the next pump, and a timingmontrol foradetermining thezperiod of op- :erationof ;each1pump and: the time interval be- :tween-eachzperiodoi operation.

515.11 :dea'cing systemior aircraft, vessels, or :the, like, comprising a :plurality of pumps adapted :to bedntermittently operated,:motor meansto ac- .tuatetsaid :pumps an actuator for said motor .means,;.and:controlzmechanism for energizing said rfirstone pump and then another-pump, said control mechanism including aartimingcontrol. forrdetermining the periodofac- :tuation :of reach; pump :andithe frequency of said :periods.

16. A de-icing system for aircraft, vessels, or the like, :comprising 'a plurality of pumps 'adapted to beiintennittently operated, an electric'motor ;for each pump, ran electricallyoperated actuator fior iencrgizing .one .imotor before energizing the 9' A de icing sy tem-f ,airc aft vesselsirorthe :next motor,-xand:an:electric circuit for energizing like, comprising .a pluralityof electricallyoperated .pumps, :an Y operating switch for ea'ch pump, an actuator for selectively closing said switches to efiect intermittent operation of said pumps, a switch 'for controllin the power toeach operating switch, said actuator having means 'to predeterminethe period of closing-of said power switch to limitthe 'flow of current to thepump-energized. .10. 'A de-icing system for aircraft, vessels, or athe like, comprising=a plurality 'of electrically operated-pumps, an operating-switch for'each pump, --a .cam unit. for selectively closing said-operating switches :to inter-mitt ently: op era te sai'cl pumpsaan actuator for said cam-unit, and a=switch for'controlling the power to each-operating switchg and :means Ttof limitthe ffiow of: current through-said operatingrswitches and 'tosaid' pumps irrespective 101 theiactiomofssaid camunit to:open'said operat- :ing-zswitches.

1111. :A fdesicingsystemifor aircraft, vessels, or

:-.the like, comprising a pluralityofelectrimillyop- -erated :pumps, i3, tpump :relay :assembly including -.anzoperating switch forieach pump andaswitch for controlling thezpower to eachoperating switch, :an actuator d or ;closing; said switches, and means toilimit the; period of closing;ofisaidipower control switch.

12. A :de icing system for aircraft, ivessels,-:o1' the like, :comprisingza plurality of electrically op- ..erated pumps,;a;pump relay.includingzanopera ing switch for-each plimpzanda switchxfor con- -trolling the power to :each cioperatingsswitch, an actuator for closing. said :switchesgmeanszm limit .the' period of closing ofi-saidpower.controlswitch,

and :means to :control the frequency :of;saidpe- .riods of closing of said powencontrol switch.

.13. .A de-icing "system for aircraft, ivessels, ior .theilike, comprising 'a plurality-of :electricallyiop- :said actuator; there being. means torpredetermine :therperiod: of :operation :ofsaid actuator and the :frequencyotthe same.

17. :A :deeicin'g system :for aircraft, vessels, or

- 40 :the '1ike,:comprising1 aplurality I of pumps-adapted to be iinterm'ittently :operated, an electric motor .forceach :pump, ;a 'ISCQIIEHCB- relay for r opening and .closing the;circuits.ofzsaid-motorsand an electric timing circuit .includingactuating means therein forsaidsequence. relay and zmeansjfor energizing .said actuatingmeans ibyzcurrent impulses of pre- -.determined -frequencyzand :duration.

.1 8. A ;de-;icingrsyst.em 101- aircraft, wessels, or -the like, :comprising :pumping :meansifor supplying .ade-icingsolution, .motor :means for operatingsaid-pumpingmeans, anactuator for said-m0- ztor meansga controlsrelayifor: operating said acturator, and an elec tronicitiming circuit for supplying current impulses to said control relay,-said circuit including-.means-ctogpredetermine the freouencyand duration-oiisaidicurrent impulses.

*WrAL'IIER C..: HASSELHORN.

REEERENCES CITED The following references are of record in1the 'ifile of'sthis patent:

UNITED STATES PATENTS -l\lunlber

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