CA1175280A - Sweeping air stream apparatus and method - Google Patents
Sweeping air stream apparatus and methodInfo
- Publication number
- CA1175280A CA1175280A CA000349839A CA349839A CA1175280A CA 1175280 A CA1175280 A CA 1175280A CA 000349839 A CA000349839 A CA 000349839A CA 349839 A CA349839 A CA 349839A CA 1175280 A CA1175280 A CA 1175280A
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- Prior art keywords
- air
- invention defined
- weight
- vane
- spring
- Prior art date
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Abstract
SWEEPING AIR STREAM APPARATUS AND METHOD
ABSTRACT
In an automobile air flow system, air is forced through an air outlet element or nozzle (13, 21, 24) in a sweeping air stream pattern by an oscillating reed or vane member (42) supported solely at the downstream end (43) for air initiated oscillatory movement in the flow path of the air from the source; a weight (41) is on the free, upstream end of the vane and is of a size such that the rate of oscillation is determined by the spring constant of a spring in the vane member and the weight.
The oscillating vane (42) is proportioned with respect to the cross sectional size of the outlet such that at any extreme of its oscillatory movement is does not physically contact any other structural member. In one embodiment the oscillating reed is a flat spring which is rendered clickless or silent by limiting directions or bending of the reed element to an axis transverse to the direction of air flow preferably by a bend (78) in the body of the element.
The oscillatory member includes an weight or impinge-ment element secured to the upstream end of the flat spring, the rate of oscillation of the impingement mem-ber being directly related to and substantially deter-mined by the spring constant and the weight of the weight or air impingement element. In a further emboidment of the vane, a pair of spaced apart, elongated coil springs (91, 92) carry a flexible sheet (95:) therebetween and a weight (98A and 98B) on the upstream end.
The sweep frequency in a defrost system for a wind-shield is low enough compared to the velocity of the jet so that the wavelength is long compared to the nozzle to windshield distance, This will assure minimal mixing of defrost air with ambient and this maximize the inten-sity of heated air on the windshield.
ABSTRACT
In an automobile air flow system, air is forced through an air outlet element or nozzle (13, 21, 24) in a sweeping air stream pattern by an oscillating reed or vane member (42) supported solely at the downstream end (43) for air initiated oscillatory movement in the flow path of the air from the source; a weight (41) is on the free, upstream end of the vane and is of a size such that the rate of oscillation is determined by the spring constant of a spring in the vane member and the weight.
The oscillating vane (42) is proportioned with respect to the cross sectional size of the outlet such that at any extreme of its oscillatory movement is does not physically contact any other structural member. In one embodiment the oscillating reed is a flat spring which is rendered clickless or silent by limiting directions or bending of the reed element to an axis transverse to the direction of air flow preferably by a bend (78) in the body of the element.
The oscillatory member includes an weight or impinge-ment element secured to the upstream end of the flat spring, the rate of oscillation of the impingement mem-ber being directly related to and substantially deter-mined by the spring constant and the weight of the weight or air impingement element. In a further emboidment of the vane, a pair of spaced apart, elongated coil springs (91, 92) carry a flexible sheet (95:) therebetween and a weight (98A and 98B) on the upstream end.
The sweep frequency in a defrost system for a wind-shield is low enough compared to the velocity of the jet so that the wavelength is long compared to the nozzle to windshield distance, This will assure minimal mixing of defrost air with ambient and this maximize the inten-sity of heated air on the windshield.
Description
`` SPECI~ICATION
B~C'~G~OU~ D BRIEF DESCRIPTION OF THE I~VENFrON
The invention generally is directed to ~;r ~GW and distributicn syst0ms an~ m partlcular, to the ~reated air rlow systems in automobiles such as defrosters, air condition-ing and heating systems.
In automoDile systems, the defrost system and the air conditioning system as well as the heating system typically are all contained under the dashboard and prior 10 art efLorts to use standard (feedback) type fluidic noz-zles while, basically, functionally good in sweeping a jet of air across the windshield, physical size of the fluidic element is much too large to rit within the dash, particularly in small and downsized automobiles. For lj example, the outlet of some automobile ducting is about 3 X 5 inches. I one were to use the samller 3" dimen-slon for the power nozzle width (W) of the fluidic ele-ment, the resultant length of the nozzle would be too long. Experiments with the resultant swe~ping air jet ~O from such a large element to discover more about its uni~ormity characteristics in the air showed chat the frequency standard of the oscillator is in the order of 10 Hz and at an air velocity of about 100 feet per second the characteristic wavelength is in the order of about 25 10 feet wllich is satisfactory. Various electrically powered oscillatory elements have been suggested,'rLowever they add cost, compleYity and maintenance problems and are not silent.
The operational basis ror the oscillating jet is 30 that a concentrated jet would be uniformly swept over the windshield so that the intensity of the heat, because of minimal mixing with ambient, would be maximized at the point of impact of the air stream but would be uniformly distributed by the sweeping action In order to accomp-js~-,~
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lish this, the sweeping rate or frequency of the air stream must be low enough compared to the velocity of the air jets so that the wavelength is long compared to the nozzle. When the wavelength is long, a small portion of the stream resides in the ambient air before impacting the windshield. On the other hand, with a short wavelength much of the s-tream resides in the ambient air, producing severe mixing with the ambient, which for defrost purposes tends to defeat the purpose at hand.
However, for air conditioning purposes, a low sweeping rate is desired in the initial cool down phase of the air confined within the automobile and, after the vehicle has been cooled down, a mixing with the ambient is desired so as to maintain the temperature. This dual sweep frequency concept is also desirable for the heating of the vehicle that is to say, the initial heating is obtained by a low rate or frequency of sweeping of the air stream in the passenger compartment in order to more rapidly cool down or heat up the passenger comp-artment and then, after a short time interval the sweep rate is increased to thereby produce mixing of the freshly cooled or heated air with the air in the passenger compartment.
The present invention resides in an air flow system having a soùrce of air under pressure flowing through a channel coupled to an outlet element for issuing a sweeping air stream pattern. The system has a resilient vane oscillatory element in the outlet element, the resilient vane having a longitudinal axis and means securing the downstream end only of the vane in fixed relation to the outlet element with the upstream end of the resilient vane being free and oscilla-table, solely by air flow, between a pair of extreme positions, the extreme
B~C'~G~OU~ D BRIEF DESCRIPTION OF THE I~VENFrON
The invention generally is directed to ~;r ~GW and distributicn syst0ms an~ m partlcular, to the ~reated air rlow systems in automobiles such as defrosters, air condition-ing and heating systems.
In automoDile systems, the defrost system and the air conditioning system as well as the heating system typically are all contained under the dashboard and prior 10 art efLorts to use standard (feedback) type fluidic noz-zles while, basically, functionally good in sweeping a jet of air across the windshield, physical size of the fluidic element is much too large to rit within the dash, particularly in small and downsized automobiles. For lj example, the outlet of some automobile ducting is about 3 X 5 inches. I one were to use the samller 3" dimen-slon for the power nozzle width (W) of the fluidic ele-ment, the resultant length of the nozzle would be too long. Experiments with the resultant swe~ping air jet ~O from such a large element to discover more about its uni~ormity characteristics in the air showed chat the frequency standard of the oscillator is in the order of 10 Hz and at an air velocity of about 100 feet per second the characteristic wavelength is in the order of about 25 10 feet wllich is satisfactory. Various electrically powered oscillatory elements have been suggested,'rLowever they add cost, compleYity and maintenance problems and are not silent.
The operational basis ror the oscillating jet is 30 that a concentrated jet would be uniformly swept over the windshield so that the intensity of the heat, because of minimal mixing with ambient, would be maximized at the point of impact of the air stream but would be uniformly distributed by the sweeping action In order to accomp-js~-,~
., `~
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lish this, the sweeping rate or frequency of the air stream must be low enough compared to the velocity of the air jets so that the wavelength is long compared to the nozzle. When the wavelength is long, a small portion of the stream resides in the ambient air before impacting the windshield. On the other hand, with a short wavelength much of the s-tream resides in the ambient air, producing severe mixing with the ambient, which for defrost purposes tends to defeat the purpose at hand.
However, for air conditioning purposes, a low sweeping rate is desired in the initial cool down phase of the air confined within the automobile and, after the vehicle has been cooled down, a mixing with the ambient is desired so as to maintain the temperature. This dual sweep frequency concept is also desirable for the heating of the vehicle that is to say, the initial heating is obtained by a low rate or frequency of sweeping of the air stream in the passenger compartment in order to more rapidly cool down or heat up the passenger comp-artment and then, after a short time interval the sweep rate is increased to thereby produce mixing of the freshly cooled or heated air with the air in the passenger compartment.
The present invention resides in an air flow system having a soùrce of air under pressure flowing through a channel coupled to an outlet element for issuing a sweeping air stream pattern. The system has a resilient vane oscillatory element in the outlet element, the resilient vane having a longitudinal axis and means securing the downstream end only of the vane in fixed relation to the outlet element with the upstream end of the resilient vane being free and oscilla-table, solely by air flow, between a pair of extreme positions, the extreme
- 2 -pc/ ,'~
~7521~0 positions being short of contacting the outlet element and the channel and causing the air to issue in a sweepiny air stream pattern from the outlet element.
When used in the air treatment system of an automobile, it satisfies the requirement of small space and minimizes ambient mixing for defrost operation (which is undesirable since it lowers the thermal energy of air impacting -the windshield). The present invention provides an oscillator whose frequency is independent of the air stream properties and whose frequency is characteristically low.
However, the învention may also provide an oscillator whose frequency can be changed dependent upon time and/or temperature to achieve an initial low frequency of operation so as to assure a rapid heating and/or cooling of the passenger compartment and subsequently, a higher frequency of oscillation to assure a better mixing characteristic tin contrast to the defrost operation) after the passenger compartment has been cooled or heated for a selected period of time.
In one embodiment of the present invention there is provided a vibrating reed air stream oscillator, constitu-ted by a thin.resilien-t vane in the shape of an inverted "T" which is supported in cantilevered fashion from the stem of the "T" in the duct. This provides an air initiated oscillation mechanism which is extremely reliable, very low in cost and can be installed or incorporated in existing defrost systems without significant structural modification and which does not require any additional space. In fact, the invention can reduce the space requirements since it results in a much more efficient and rapid defrost of an automobile windshield by . 3 pc/~
~:~7~
concentrating the heated air rather than diffusing it over a wide or long path. That is to say, instead o~ a difEuser of wide angles, the air stream is swept over the wide angle and, in some cases, a single defrost air outlet adjacent to the windshield can accommodate the entire windshield.
The oscillating element of the present invention solves the problems in a simple, efficient relatively maintenance free and inexpensive manner.
According to one embodiment of the invention an oscillatory member is supported in the air outlet element of an automobile air flow system, said oscillatory member being constituted by a resilient vane or reed secured at its down-stream end proximate the center of the air outlet element, the free upstream end has a weighted air impingement surface and is proportioned with respect to the cross-sectional size of the outlet element that during oscillatory movement there is no physical contact with any structural portion of the outlet èlements. In defrost/defog systems, the frequency of oscillation is such that the wavelength is long relative to the distance from the outlet element to the windshield surface thereby minimizing mixing of defrost/defog air with ambient air. In hèàting and air conditioning systems higher initial frequencies, and hence shorter wavelength, are desirable to obtain better mixing to obviate hot or cold spots. Rapid heating/cooling of the passenger compartment, initially requires subsequently lower frequency-longer wavelength.
The vane is fairly broad and wide and acts like a moving wall to deflect or direct the exiting air jet stream in a sweeping fashion. Since the reed or vane is wide and its upstream end unsupported and during its travel in any il - 4 -pc/~
direction it must not con-tac-t any structure, the fluid air stream can and do at times distort the bending axis of the reed and thereby creating a clicking. However, such noise making is very undesirable particularly in the closed space of an au*omobile and, because of the distortion in the spring metal itself, tends to greatly reduce the life of the element when used as an oscillator. A further feature of the present inventlon provides improved oscillating reed structures which are essentially clickless or noiseless and have long opera-ting lifes.
In a speclfic embodiment this is achieved by providing a transverse stiffening of the reed element in directions transverse to the direction of air flow so as to limit bending of the reed elemen-t during its oscillations along an axis which is transverse to the direction of air flow.
That is to say, the axis of stiffening is parallel to the bending axis but it does not detract from the flexibility and oscillating function of the device. In a disclosed embodiment, the bending is a gentle curvature o bending of the reed element over substantially the entire body. In addition, the body of the reed support element has a slot in it with *he mouth of the slot gently rounded or smoothed to receive and clamp the downstream end of the reed element so that there are no sharp edges against which the body of the reed element is engaged during oscillation. Moreover the edges of *he reed element is polished to remove notches etc... all of these features avoiding metal fatigue of -the reed body leading to extended life of the oscillator element per se.
In a further specific embodiment, the oscillating ~- 5 -pc/ "
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vane is constituted by a pair of spaced coil springs with an elastomeric sheet between them and a weight. This flexible assembly is inherently clickless and the stress in the coil spring is very low even for large flexural deflections so that fatigue is no problem. Apart from the requirement that there be no physical contact with sidewalls etc... during oscillatory movement of the vane, no special handling of the materials or precise tolerance is required.
BRIEF DESCRIPTI`ON OF THE DRAWINGS
The above and other objectives, advantages and eatures of the invention will become more apparent from the following specification when considered in conjunction with the accompanying drawings wherein:
Figure 1 (and inset thereto) is an isometric perspective view of an automobile defrost system and its proximity to the windshield of an automobile to which the invention has been applied;
Figure 2a illustrates the sweeping rate (frequency) of the air stream must be low enough compared to the velocity 2~ of the jet so that the wavelength is long compared to the nozzle to windshield distance, Figure 2b shows that when the wavelength is long, a small portion of the stream resides in the ambient air before impacting the windshield, Figure 3 illustrates the rèlationship between the air stream wavelength, the velocity of propagation and the frequency of oscillation, -- 5a -pc/ ~ ' --~7 ~'~8 ~
Figuxe 4a illustrates a fixed oscillation element primarily for de~ros~/detog use and Fi~ure 4b ill~s~rates a manually ad~ustable oscillatory element flwo director ~oth figures being according to preferred embodiments 5 OL- this invention;
Figure 5 is modification of the oscillatory element shown in Figure 4~ to whicn an.oscillatory rate control runction has been applied for controlling the ra~e of oscillation of the oscillating element, Figure 6 is a detailed cross-sectional view of the ~riction he.ld manua~ control arrangement of Figure 4b, Figur~ 7 is a partial isome~ric perspect.lve view of an automobile defrost nozzle incorporating the in-vention, Figure 8 is an enlarged side perspect.ive viewof the mounting ~ar for securing the downstream end of the vibrat;ng reed and Figure 9 is an isometric perspective view of the oscillating reed of the present invention showing the weight attachment and the bend therein.
Figure 10 is a partial isometric view of an auto-mobile heat/air conditioning nozzle incorporating 2 coil spring-elastomeric vane modification or ~he oscillating 25 vane of the present invention, Figure ll is an isometric view of the coil spring-elastomeric vane shown in Figure 10, Figure 12 is a cross-sectional view along lines 12-12 of Figure 11, Figure 13 is a cross-sectional view along lines 13 13 of Figure ll and, Figure 14 is an enlarged side elevational view of a typical coil spring and its dimensions.
DET~ILED DESCRIPT_ON OF TXE INVENTION
The invention will be..described ~ith particular reference to that automobile air flow system.
As sh~wn in the embodiment illustrated in Figure 1, a windshield defrost system according to the invention includes a conventional heater i0 which is usually in-stalled underneath the dashboard or instrument panel 11 connected, via main duct work 12 to defrost/defog nozzle 13. ~he nozzle 13 is connected via duct 15 to main duct-wor~ 12 but, it will be appreciated that separate pas-sage ways or ducting may be utilized for connecting out-let nozzles to car heater 10 in the event ~WO nozzles are used. Nozzle 13 has an outlet opening 17, juxtaposed so as to direct air over the inner sur~ace or windshield 20.
Air fox- heating the interior of the passenger comp-artment is delivered through separate nozzle 21 for di-recting air from common duct 12 to the interior compart-ment of the vehicle. It will be appreciated that con-2~ trol linkages and/or cables for controlling valving induct 12 for directing all the air to outlet nozzle 13 for defrost purposed,_and/or to the outlet no2z1e 21 for heating the interior compartment of t~e vehicle are standard control instrumentalit.ies and hence. do not per se form a part of~ the pre.sent invention. By the same to.ken, in some automobiles the outlet air nozzle 21 can be connected to a source of outside aix for vent-ing purposes.
Still referring to Figure 1, there is shown air con-ditloning outlet nozzle 24 which is connected to a con-ventional automobile air conditioning unit and air cir-culation system 25, it beinO appreciated that outlet 21 can also be used for supplying air from the air cond-itioning unit to the passenger compar~.ment. The heat/de~rost door or valve assembly and motor, the air cond-i~ioner evaporator case and assembly as well as the blower motor and an intake are conven~ional and not illustrated in detail.
~ ost fluidic nozzles have a characteris~ic wave-length ~ which is a constant or a given size noz~le, constant over a varlety or pressures and has a fre~uency characteristic which is llnear with velocity. The wave-length is a function of ~he velocity of propagtion and the frequency of oscillation so that V
wherein:
~ equals the wavelength o, the oscillating stream, V'e~als velocity of stream propagation and F equals the frequency of oscillation.
. Fi-gure 2a and 2b illustrate the patterns on an auto-mobile windshield 20' of the operational basis for oscil-lating the air iet such that a concentrated jet is uni-formly swept over the windshield 20' so that the inten-sity of the heat, because o~ minimal mixing of heated air with the ambient air, will be maximized at the po~nt of impact of the air stream on the windshiel~. and thls .. . . .... . .. . .. ..
erfect is unifo~mly distribut.ed by.the sweeping action over the windshield surface. The relationshi? of the sweeping rate Cfr~quency3 of the air stream issuing from nozzle 30 (Figure 2a) and the noz21e 31 (Figure 2b) respectively to windshiel~ distance D is illustrated in Figures 2a and.2b . Whe~ the ~avelength is long relative to distance D,. a small portion of the stream resides in the ambient ai just before impac~ing the win~shieid.
This is illustratedin ~igure 2~ and labled:short stre.~m length residence ~minimum ambient mixing3. When the wave-length is short r.elative to distance D,a much larger , 8 ~ ",!
portion of the air stream resides in the ambient air before impacting the windshield; this is illustrated in Figure 2b and legended "long stream length resldence (maximum ambient mixing)". For the defrost operation, the operation illus-trated in Figure 2a is used.
As discussed earlier in connection wlth the improvements in efficiency in the cooling and heating of the passenger compartment, after the initial heating or cooling of the passenger compartment has taken place it ls desirable that maximum ambient mixing condition be brought into play.
~owever, the short stream length residence for minimum ambient mixing is desirable in the heating and cooling situation in the initial heating or cooling cycle of the passenger compartment. Reference is made to Figure 5 which discloses the control over the oscillating element to achieve a situation shown in Figure 2a and Figure 2b.
THE OSCILLATOR ELEMæNT OF THIS INVENTION
Referring now to Figure 4a, the duct or channel 40 carrying air under pressure from the blower in the defrost unit 10 is directed to an oscillatory impingement member or element 41. Oscillatory impingement element 41 is supported for oscillatory movements by a thin metal reed 42, which together with the oscillatory "T" which is cantileverly supported from the stem of the "T" at a fixed support 43.
Air passing through duct 40 will impinge on the cross part of the "T" shaped element and initiate oscil-lation thereof. The spring 42 (which is the stem part of the "T" reed) and the mass (,the cross part of oscillatory impingement member 41) act together as a spring-mass system which is forced to oscillate by the air flowing by it.
The stem 42 of the "T" reed acts like a moving wall to deflect the exiting air stream in an os-,r~
~ f~ mab~
~.~75~
cillatory, sweeping ma~ner across windshield 20.
The re~uency is constant for any air velocity since it is determined primarily by the spring-mass characteristics of the "T" system. Therefore, it is easy to select parameters to produce a low frequency (say about 4 hertz- Hz) so that the oscillating air streams wavelength is = ~ = 100 fe~t ~er second = 25 feet ertz Furthermore, the overall length of the device can be made very short so that under the dash space is conserved and may even ~e reduced. No additional or special re-quirements are needed for the power source or feed ducting as it operates over. extremely wide range of air flows.
The same vibrating reed system can be used to cause lS the sweeping mo~ion of the air stream entering an auto-mobile passenger compartment for the purpose of more ef-ficiently conditioning the air. Thus, as described earlier herein, the air stream can initially have a long wavelength, the oscillatory frequency of vibrating reed 2n oscillatory impingement member 41'-42' being low, so that the short stream length provides good throw to more efiiciently heat up space remote from the outlet nozzle and, after a period of time changed to a shorter wa~elength to provide greater mixing with the ambient 25 air (see Ficure 2~). In Figure 4b t.he oscillating ele ment has the shape of an ''L" with the stem 42' being a thin metal reed and t~e cross or let 41' of the "~" be-ing impinged upon by the air flow in passage way 40'.
There are times when it is desirable in the heat-30 ing and cooling application that the air stream be confined to a pæticular location in the passenger com-partment, such as to the driver's side. As described above, the oscillatory impingement member can be cap-tured at a selected position in the outlet nozzle elementto prevent oscillation thereof and to cause air to issue from the outlet in a non-sweeping air stream pattern.
As shown in Figure 4b and Figure 6 the air oscillating element is mounted on a lever 50 which projects a short distance beyond the end of the nozzle so as to be accessable to the passenger compartment to serve as a flow controller and also as a pointer or indication of the d~rection of air flow. Flow director lever 50 is mounted on a pivot pin 51 extending between walls 40-A and 40-B
of air passageway 41 and one or more friction elements or washers 52 friction elements 52, which may be integrally formed on the walls 40-A and 40-B, serve to retain lever 50 and the oscillatory member 41'-42' at any passenger selected position in the air stream. In the position illus-trated in full lines in Figure 4b the air stream is deflected or directed to flow, to the right and is not oscillated or swept. When lever 50 is centered and substantially aligned with the a~r passageway 40', oscillatory element 41'-42' is set into osciallation by the air flow through the passageway thereby imparting a sweeping movement to the air stream. Since the cross member 41' is more on one side of the passageway, more air will be directed to the opposite side and therefore can serve as a means to favor the distribution of air in the passenger compartment to the driver's side, if desired.
The oscillatory rate change feature is illustrated in Figure 6. ~ccording to this feature the length of the reed element 42 is adjusted to adjust the rate of oscillation. Flow director lever 50 is provided with an elongated slot 60 which has side walls 61 and 62 which frictionally engage pivot 51' to which the stem 42" of the oscillating element is secured (it being mab~ ~
~.~7~
appreciated that the pivot ~ay be integrally formed on the end of the stem). The stem 42' ~asses ~hrough a slit 63 in the end of lever 51. The surfaces ~3S of s~it 63 slidingly engage the suraces of the stem 42" to thereby lengthen or shorten the length of the spring and hence lower and raise ~he oscilla~ory fr2q.uency by pulling lever 51' ou~ or pushing it i~, respectively. Friction washer or elements 52 also serve to malntain the adjusted position of lever 51' ~ith.respect to stem 42".
Referring to Figure 7 the duct or channel 70 o~ an automobile windshield defrost system is illustrated and it is connected to a source of defros~ air for defrost operation. As noted above the inven~ion c~n be applied to other. air.supply systems such as heating and cooling systems for automobiles and can be beneficially applied ~ith e~ual facility to air supply systems where it is desired to sweep the air bac~ and forth as for ex~mple, from a room air conditioner. The outlet nozzle 71 has 2 pair of spaced flaring walls 12-1 and 12-2 respe~tively 20 joined by a pair of side walls 73, one of which is shown in Figure 7. A vibrating reed oscillator element 75, described in greater detail in connection with Figure 9, has the downstream thereof 76 secured in a mounting bar assembly 77 (described more fully in connection with Figure 8~ mounting bar 77 being secured to side walls 73.. A curvature 78 or.bend is pr.ovided in the b.ody of the r.eed eIement 75 which sti~.fens the bod~.cI the ele-ment so that it generally f.le.~es abou~ an a~is transverse to the direction of air flow and in this embodiment the 30 air flow axi~ is denoted generally by the line "L". .~ny bending movement of the.reed eIement 75 about any non-parallel axis such as its longitudal axis 1, is prevented by the bend 78.
It will be appreciated that a series of transverse corrugations alor.g.the.entîre length of the body ele-ment 75 can achieve the same objective as tne gentle ~7~
curvature or bend 78, as well as a series of sti~rener elements spaced along the entire operating length of the body 75 and spaced relatively short distances from one another can achieve the same objective which i3 to pre-vent cross or ~wist bendlng of the body of the reed ele-men~ 75 and to limit the bending about ~he a~is "T" or any axis parallel thereto.
The upstream e~d 80 has a weight 81 riveted there-to,. the weight 81 hav~g a.slot 82 therein into which L0 the upstream e~d 80 of vibrating reed elemen~ 75 is re-ceived a~d riveted therein or otherwise secured. ~s shown in Figure 9, in the preferred embodiment the reed element is constituted by spring steel. In an operating example, the spring steel was a number 301 spring steel fully hardened, but it will be appreciated that most degrees of hardness o spring steel can be utilized to practice the invention. Fully hardened.spring steel has a tensil strength of approximately 175,000 psi minlmum and the extra hard spring steel 301 has a tensil strength of over 200,0Q0 psi, both of which are useful in p~ac-ticing the invention. Also J the weight 81 was 14 grams, having a width of .058 inches a thickness of .512 inches, and a width tXe same as the width of the reed element 75.
namely 2.235 inche-s _The ~eed itself has a thickness of .005 inches. The bend 78 in the pr~ferred emb.odime~t`
was formed by xolling the bod~ oL the reed element 75 over a 1l2 inch cylinde~._ In ~he illust~ated embodiment, the bend 78 has a radi.ous of abou~.3 inches but this is not critical. What is ~mportant though is t~e twisting 30movements of the reed element be resisted so as to avoid bending of the body of the reed element about an axis other than those which are parallel to a secured do~-stream end 76 of reed element 75.
As is conventional n the manufac~ure of springs, the edges ~1 and 92 of the reed el ~ nt are pol~hed to.el~te ~5 ~ ~
~otches burrs and th~ Like and the ~ nstrP~m end 76 of the ele-~nt is-se ed in I~unting bæ assembl7 77. ~unting asseIbly 77 s constituted by a pair of plates 77-1 and 77-2 which has a slot 85 or space therebetween, the opposing edges or corners 86 and 87 of the slot bei~g rounded (a radius of at least 1/8 inch) so that there are no sharp edges against which the body of the reed element bears during the bac~ and forth oscillatory movement. Thin rubber snims 77-S are positloned on each side of reed element 7~ to serve as cushions. Rivets 88 are used to secure the end ~6 of the reed element 75 in the mounting bar assembly 77 and the mounting bar assembly 77 is secured by screws, welding or releasable fasteners in the side-walls 73 (only one sho~n) of the outlet element. Tlle lS mounting bar can also be formed of plastic material, if desired.
With reference to Figure 9, for use in sweeping the defrost air of a Pinto automobile (manufactu~ed by the Ford Motor Company) a typical reed element was made O~ rully hardened 301 spring steel (175,000 psi) having a thic~ness of .005 inches a width of 2.235 inches and a length between the upper edge of the weight 81 and the lower edge of mounting bar assembly 77 of ~.4~7 inches.
The weight 81 had the dimensions and r~eight given above.
.. . .
t:wilI be appreciat-ed that since the inverted "T"
e~g., the oscillatory impingement el~m~nt, is only required to oscillate at relativeIy low rates, the move-ment is limited thereby minimizing the material problem.
And in view of the relative simplicity of and co~pactness
~7521~0 positions being short of contacting the outlet element and the channel and causing the air to issue in a sweepiny air stream pattern from the outlet element.
When used in the air treatment system of an automobile, it satisfies the requirement of small space and minimizes ambient mixing for defrost operation (which is undesirable since it lowers the thermal energy of air impacting -the windshield). The present invention provides an oscillator whose frequency is independent of the air stream properties and whose frequency is characteristically low.
However, the învention may also provide an oscillator whose frequency can be changed dependent upon time and/or temperature to achieve an initial low frequency of operation so as to assure a rapid heating and/or cooling of the passenger compartment and subsequently, a higher frequency of oscillation to assure a better mixing characteristic tin contrast to the defrost operation) after the passenger compartment has been cooled or heated for a selected period of time.
In one embodiment of the present invention there is provided a vibrating reed air stream oscillator, constitu-ted by a thin.resilien-t vane in the shape of an inverted "T" which is supported in cantilevered fashion from the stem of the "T" in the duct. This provides an air initiated oscillation mechanism which is extremely reliable, very low in cost and can be installed or incorporated in existing defrost systems without significant structural modification and which does not require any additional space. In fact, the invention can reduce the space requirements since it results in a much more efficient and rapid defrost of an automobile windshield by . 3 pc/~
~:~7~
concentrating the heated air rather than diffusing it over a wide or long path. That is to say, instead o~ a difEuser of wide angles, the air stream is swept over the wide angle and, in some cases, a single defrost air outlet adjacent to the windshield can accommodate the entire windshield.
The oscillating element of the present invention solves the problems in a simple, efficient relatively maintenance free and inexpensive manner.
According to one embodiment of the invention an oscillatory member is supported in the air outlet element of an automobile air flow system, said oscillatory member being constituted by a resilient vane or reed secured at its down-stream end proximate the center of the air outlet element, the free upstream end has a weighted air impingement surface and is proportioned with respect to the cross-sectional size of the outlet element that during oscillatory movement there is no physical contact with any structural portion of the outlet èlements. In defrost/defog systems, the frequency of oscillation is such that the wavelength is long relative to the distance from the outlet element to the windshield surface thereby minimizing mixing of defrost/defog air with ambient air. In hèàting and air conditioning systems higher initial frequencies, and hence shorter wavelength, are desirable to obtain better mixing to obviate hot or cold spots. Rapid heating/cooling of the passenger compartment, initially requires subsequently lower frequency-longer wavelength.
The vane is fairly broad and wide and acts like a moving wall to deflect or direct the exiting air jet stream in a sweeping fashion. Since the reed or vane is wide and its upstream end unsupported and during its travel in any il - 4 -pc/~
direction it must not con-tac-t any structure, the fluid air stream can and do at times distort the bending axis of the reed and thereby creating a clicking. However, such noise making is very undesirable particularly in the closed space of an au*omobile and, because of the distortion in the spring metal itself, tends to greatly reduce the life of the element when used as an oscillator. A further feature of the present inventlon provides improved oscillating reed structures which are essentially clickless or noiseless and have long opera-ting lifes.
In a speclfic embodiment this is achieved by providing a transverse stiffening of the reed element in directions transverse to the direction of air flow so as to limit bending of the reed elemen-t during its oscillations along an axis which is transverse to the direction of air flow.
That is to say, the axis of stiffening is parallel to the bending axis but it does not detract from the flexibility and oscillating function of the device. In a disclosed embodiment, the bending is a gentle curvature o bending of the reed element over substantially the entire body. In addition, the body of the reed support element has a slot in it with *he mouth of the slot gently rounded or smoothed to receive and clamp the downstream end of the reed element so that there are no sharp edges against which the body of the reed element is engaged during oscillation. Moreover the edges of *he reed element is polished to remove notches etc... all of these features avoiding metal fatigue of -the reed body leading to extended life of the oscillator element per se.
In a further specific embodiment, the oscillating ~- 5 -pc/ "
~IL7~
vane is constituted by a pair of spaced coil springs with an elastomeric sheet between them and a weight. This flexible assembly is inherently clickless and the stress in the coil spring is very low even for large flexural deflections so that fatigue is no problem. Apart from the requirement that there be no physical contact with sidewalls etc... during oscillatory movement of the vane, no special handling of the materials or precise tolerance is required.
BRIEF DESCRIPTI`ON OF THE DRAWINGS
The above and other objectives, advantages and eatures of the invention will become more apparent from the following specification when considered in conjunction with the accompanying drawings wherein:
Figure 1 (and inset thereto) is an isometric perspective view of an automobile defrost system and its proximity to the windshield of an automobile to which the invention has been applied;
Figure 2a illustrates the sweeping rate (frequency) of the air stream must be low enough compared to the velocity 2~ of the jet so that the wavelength is long compared to the nozzle to windshield distance, Figure 2b shows that when the wavelength is long, a small portion of the stream resides in the ambient air before impacting the windshield, Figure 3 illustrates the rèlationship between the air stream wavelength, the velocity of propagation and the frequency of oscillation, -- 5a -pc/ ~ ' --~7 ~'~8 ~
Figuxe 4a illustrates a fixed oscillation element primarily for de~ros~/detog use and Fi~ure 4b ill~s~rates a manually ad~ustable oscillatory element flwo director ~oth figures being according to preferred embodiments 5 OL- this invention;
Figure 5 is modification of the oscillatory element shown in Figure 4~ to whicn an.oscillatory rate control runction has been applied for controlling the ra~e of oscillation of the oscillating element, Figure 6 is a detailed cross-sectional view of the ~riction he.ld manua~ control arrangement of Figure 4b, Figur~ 7 is a partial isome~ric perspect.lve view of an automobile defrost nozzle incorporating the in-vention, Figure 8 is an enlarged side perspect.ive viewof the mounting ~ar for securing the downstream end of the vibrat;ng reed and Figure 9 is an isometric perspective view of the oscillating reed of the present invention showing the weight attachment and the bend therein.
Figure 10 is a partial isometric view of an auto-mobile heat/air conditioning nozzle incorporating 2 coil spring-elastomeric vane modification or ~he oscillating 25 vane of the present invention, Figure ll is an isometric view of the coil spring-elastomeric vane shown in Figure 10, Figure 12 is a cross-sectional view along lines 12-12 of Figure 11, Figure 13 is a cross-sectional view along lines 13 13 of Figure ll and, Figure 14 is an enlarged side elevational view of a typical coil spring and its dimensions.
DET~ILED DESCRIPT_ON OF TXE INVENTION
The invention will be..described ~ith particular reference to that automobile air flow system.
As sh~wn in the embodiment illustrated in Figure 1, a windshield defrost system according to the invention includes a conventional heater i0 which is usually in-stalled underneath the dashboard or instrument panel 11 connected, via main duct work 12 to defrost/defog nozzle 13. ~he nozzle 13 is connected via duct 15 to main duct-wor~ 12 but, it will be appreciated that separate pas-sage ways or ducting may be utilized for connecting out-let nozzles to car heater 10 in the event ~WO nozzles are used. Nozzle 13 has an outlet opening 17, juxtaposed so as to direct air over the inner sur~ace or windshield 20.
Air fox- heating the interior of the passenger comp-artment is delivered through separate nozzle 21 for di-recting air from common duct 12 to the interior compart-ment of the vehicle. It will be appreciated that con-2~ trol linkages and/or cables for controlling valving induct 12 for directing all the air to outlet nozzle 13 for defrost purposed,_and/or to the outlet no2z1e 21 for heating the interior compartment of t~e vehicle are standard control instrumentalit.ies and hence. do not per se form a part of~ the pre.sent invention. By the same to.ken, in some automobiles the outlet air nozzle 21 can be connected to a source of outside aix for vent-ing purposes.
Still referring to Figure 1, there is shown air con-ditloning outlet nozzle 24 which is connected to a con-ventional automobile air conditioning unit and air cir-culation system 25, it beinO appreciated that outlet 21 can also be used for supplying air from the air cond-itioning unit to the passenger compar~.ment. The heat/de~rost door or valve assembly and motor, the air cond-i~ioner evaporator case and assembly as well as the blower motor and an intake are conven~ional and not illustrated in detail.
~ ost fluidic nozzles have a characteris~ic wave-length ~ which is a constant or a given size noz~le, constant over a varlety or pressures and has a fre~uency characteristic which is llnear with velocity. The wave-length is a function of ~he velocity of propagtion and the frequency of oscillation so that V
wherein:
~ equals the wavelength o, the oscillating stream, V'e~als velocity of stream propagation and F equals the frequency of oscillation.
. Fi-gure 2a and 2b illustrate the patterns on an auto-mobile windshield 20' of the operational basis for oscil-lating the air iet such that a concentrated jet is uni-formly swept over the windshield 20' so that the inten-sity of the heat, because o~ minimal mixing of heated air with the ambient air, will be maximized at the po~nt of impact of the air stream on the windshiel~. and thls .. . . .... . .. . .. ..
erfect is unifo~mly distribut.ed by.the sweeping action over the windshield surface. The relationshi? of the sweeping rate Cfr~quency3 of the air stream issuing from nozzle 30 (Figure 2a) and the noz21e 31 (Figure 2b) respectively to windshiel~ distance D is illustrated in Figures 2a and.2b . Whe~ the ~avelength is long relative to distance D,. a small portion of the stream resides in the ambient ai just before impac~ing the win~shieid.
This is illustratedin ~igure 2~ and labled:short stre.~m length residence ~minimum ambient mixing3. When the wave-length is short r.elative to distance D,a much larger , 8 ~ ",!
portion of the air stream resides in the ambient air before impacting the windshield; this is illustrated in Figure 2b and legended "long stream length resldence (maximum ambient mixing)". For the defrost operation, the operation illus-trated in Figure 2a is used.
As discussed earlier in connection wlth the improvements in efficiency in the cooling and heating of the passenger compartment, after the initial heating or cooling of the passenger compartment has taken place it ls desirable that maximum ambient mixing condition be brought into play.
~owever, the short stream length residence for minimum ambient mixing is desirable in the heating and cooling situation in the initial heating or cooling cycle of the passenger compartment. Reference is made to Figure 5 which discloses the control over the oscillating element to achieve a situation shown in Figure 2a and Figure 2b.
THE OSCILLATOR ELEMæNT OF THIS INVENTION
Referring now to Figure 4a, the duct or channel 40 carrying air under pressure from the blower in the defrost unit 10 is directed to an oscillatory impingement member or element 41. Oscillatory impingement element 41 is supported for oscillatory movements by a thin metal reed 42, which together with the oscillatory "T" which is cantileverly supported from the stem of the "T" at a fixed support 43.
Air passing through duct 40 will impinge on the cross part of the "T" shaped element and initiate oscil-lation thereof. The spring 42 (which is the stem part of the "T" reed) and the mass (,the cross part of oscillatory impingement member 41) act together as a spring-mass system which is forced to oscillate by the air flowing by it.
The stem 42 of the "T" reed acts like a moving wall to deflect the exiting air stream in an os-,r~
~ f~ mab~
~.~75~
cillatory, sweeping ma~ner across windshield 20.
The re~uency is constant for any air velocity since it is determined primarily by the spring-mass characteristics of the "T" system. Therefore, it is easy to select parameters to produce a low frequency (say about 4 hertz- Hz) so that the oscillating air streams wavelength is = ~ = 100 fe~t ~er second = 25 feet ertz Furthermore, the overall length of the device can be made very short so that under the dash space is conserved and may even ~e reduced. No additional or special re-quirements are needed for the power source or feed ducting as it operates over. extremely wide range of air flows.
The same vibrating reed system can be used to cause lS the sweeping mo~ion of the air stream entering an auto-mobile passenger compartment for the purpose of more ef-ficiently conditioning the air. Thus, as described earlier herein, the air stream can initially have a long wavelength, the oscillatory frequency of vibrating reed 2n oscillatory impingement member 41'-42' being low, so that the short stream length provides good throw to more efiiciently heat up space remote from the outlet nozzle and, after a period of time changed to a shorter wa~elength to provide greater mixing with the ambient 25 air (see Ficure 2~). In Figure 4b t.he oscillating ele ment has the shape of an ''L" with the stem 42' being a thin metal reed and t~e cross or let 41' of the "~" be-ing impinged upon by the air flow in passage way 40'.
There are times when it is desirable in the heat-30 ing and cooling application that the air stream be confined to a pæticular location in the passenger com-partment, such as to the driver's side. As described above, the oscillatory impingement member can be cap-tured at a selected position in the outlet nozzle elementto prevent oscillation thereof and to cause air to issue from the outlet in a non-sweeping air stream pattern.
As shown in Figure 4b and Figure 6 the air oscillating element is mounted on a lever 50 which projects a short distance beyond the end of the nozzle so as to be accessable to the passenger compartment to serve as a flow controller and also as a pointer or indication of the d~rection of air flow. Flow director lever 50 is mounted on a pivot pin 51 extending between walls 40-A and 40-B
of air passageway 41 and one or more friction elements or washers 52 friction elements 52, which may be integrally formed on the walls 40-A and 40-B, serve to retain lever 50 and the oscillatory member 41'-42' at any passenger selected position in the air stream. In the position illus-trated in full lines in Figure 4b the air stream is deflected or directed to flow, to the right and is not oscillated or swept. When lever 50 is centered and substantially aligned with the a~r passageway 40', oscillatory element 41'-42' is set into osciallation by the air flow through the passageway thereby imparting a sweeping movement to the air stream. Since the cross member 41' is more on one side of the passageway, more air will be directed to the opposite side and therefore can serve as a means to favor the distribution of air in the passenger compartment to the driver's side, if desired.
The oscillatory rate change feature is illustrated in Figure 6. ~ccording to this feature the length of the reed element 42 is adjusted to adjust the rate of oscillation. Flow director lever 50 is provided with an elongated slot 60 which has side walls 61 and 62 which frictionally engage pivot 51' to which the stem 42" of the oscillating element is secured (it being mab~ ~
~.~7~
appreciated that the pivot ~ay be integrally formed on the end of the stem). The stem 42' ~asses ~hrough a slit 63 in the end of lever 51. The surfaces ~3S of s~it 63 slidingly engage the suraces of the stem 42" to thereby lengthen or shorten the length of the spring and hence lower and raise ~he oscilla~ory fr2q.uency by pulling lever 51' ou~ or pushing it i~, respectively. Friction washer or elements 52 also serve to malntain the adjusted position of lever 51' ~ith.respect to stem 42".
Referring to Figure 7 the duct or channel 70 o~ an automobile windshield defrost system is illustrated and it is connected to a source of defros~ air for defrost operation. As noted above the inven~ion c~n be applied to other. air.supply systems such as heating and cooling systems for automobiles and can be beneficially applied ~ith e~ual facility to air supply systems where it is desired to sweep the air bac~ and forth as for ex~mple, from a room air conditioner. The outlet nozzle 71 has 2 pair of spaced flaring walls 12-1 and 12-2 respe~tively 20 joined by a pair of side walls 73, one of which is shown in Figure 7. A vibrating reed oscillator element 75, described in greater detail in connection with Figure 9, has the downstream thereof 76 secured in a mounting bar assembly 77 (described more fully in connection with Figure 8~ mounting bar 77 being secured to side walls 73.. A curvature 78 or.bend is pr.ovided in the b.ody of the r.eed eIement 75 which sti~.fens the bod~.cI the ele-ment so that it generally f.le.~es abou~ an a~is transverse to the direction of air flow and in this embodiment the 30 air flow axi~ is denoted generally by the line "L". .~ny bending movement of the.reed eIement 75 about any non-parallel axis such as its longitudal axis 1, is prevented by the bend 78.
It will be appreciated that a series of transverse corrugations alor.g.the.entîre length of the body ele-ment 75 can achieve the same objective as tne gentle ~7~
curvature or bend 78, as well as a series of sti~rener elements spaced along the entire operating length of the body 75 and spaced relatively short distances from one another can achieve the same objective which i3 to pre-vent cross or ~wist bendlng of the body of the reed ele-men~ 75 and to limit the bending about ~he a~is "T" or any axis parallel thereto.
The upstream e~d 80 has a weight 81 riveted there-to,. the weight 81 hav~g a.slot 82 therein into which L0 the upstream e~d 80 of vibrating reed elemen~ 75 is re-ceived a~d riveted therein or otherwise secured. ~s shown in Figure 9, in the preferred embodiment the reed element is constituted by spring steel. In an operating example, the spring steel was a number 301 spring steel fully hardened, but it will be appreciated that most degrees of hardness o spring steel can be utilized to practice the invention. Fully hardened.spring steel has a tensil strength of approximately 175,000 psi minlmum and the extra hard spring steel 301 has a tensil strength of over 200,0Q0 psi, both of which are useful in p~ac-ticing the invention. Also J the weight 81 was 14 grams, having a width of .058 inches a thickness of .512 inches, and a width tXe same as the width of the reed element 75.
namely 2.235 inche-s _The ~eed itself has a thickness of .005 inches. The bend 78 in the pr~ferred emb.odime~t`
was formed by xolling the bod~ oL the reed element 75 over a 1l2 inch cylinde~._ In ~he illust~ated embodiment, the bend 78 has a radi.ous of abou~.3 inches but this is not critical. What is ~mportant though is t~e twisting 30movements of the reed element be resisted so as to avoid bending of the body of the reed element about an axis other than those which are parallel to a secured do~-stream end 76 of reed element 75.
As is conventional n the manufac~ure of springs, the edges ~1 and 92 of the reed el ~ nt are pol~hed to.el~te ~5 ~ ~
~otches burrs and th~ Like and the ~ nstrP~m end 76 of the ele-~nt is-se ed in I~unting bæ assembl7 77. ~unting asseIbly 77 s constituted by a pair of plates 77-1 and 77-2 which has a slot 85 or space therebetween, the opposing edges or corners 86 and 87 of the slot bei~g rounded (a radius of at least 1/8 inch) so that there are no sharp edges against which the body of the reed element bears during the bac~ and forth oscillatory movement. Thin rubber snims 77-S are positloned on each side of reed element 7~ to serve as cushions. Rivets 88 are used to secure the end ~6 of the reed element 75 in the mounting bar assembly 77 and the mounting bar assembly 77 is secured by screws, welding or releasable fasteners in the side-walls 73 (only one sho~n) of the outlet element. Tlle lS mounting bar can also be formed of plastic material, if desired.
With reference to Figure 9, for use in sweeping the defrost air of a Pinto automobile (manufactu~ed by the Ford Motor Company) a typical reed element was made O~ rully hardened 301 spring steel (175,000 psi) having a thic~ness of .005 inches a width of 2.235 inches and a length between the upper edge of the weight 81 and the lower edge of mounting bar assembly 77 of ~.4~7 inches.
The weight 81 had the dimensions and r~eight given above.
.. . .
t:wilI be appreciat-ed that since the inverted "T"
e~g., the oscillatory impingement el~m~nt, is only required to oscillate at relativeIy low rates, the move-ment is limited thereby minimizing the material problem.
And in view of the relative simplicity of and co~pactness
3() of the device, it can reduce the space under the dash.
Since in the preferred embodiment of the invention, the cross-sectional area of the oscillatory impingement ele-ment is smaller than the cross-sectional area of the duct to permit free movement thereof without impacting on any element, it is completely silent, consumes no ' ~ ~'7~
power and does not introduce any significant pneumatic impedaIlce and thereby does not unduly load the impeller or blower motor in the defrost unit.
Referring ~o FiO~ure 10, t~e duct or channel of an automobile heater/air conditioning s~stem is indicated as supplying air to a no2zle 21' which inco~porates a further modified form or oscillating vane constituted by the coil spring-elastomeric vane assembly 90, the de-tails of whic~ are illustrated in Figures 11-14. In ~his emboidment, a pair of spaced coil springs gL and 92 '(the dimensional parameters are shown in Figure 14 for a typical application), which are embedded in tubu-lar end sectio~s ~4 and gs of a thin sheet 93 or elas~ic or elastomeric material, such as rubber. The upstream end of tab 96 OL elastic vane go is clamped between 2 pair of weight elements 98A and 98B, which have a pair of semi-circular recesses 100 and 101 in their fac~ng edges for receiving and clamping the upstreæm or oscil-lating end of coil springs 91 and 92. The downstream 20 end or tab 106 of elastic vane go is secured between a pair of mounting bars 104-lOS r~hich are used to secure the downstream end 106 of the vane assembly to the spaced walls 107-108 of nozzle'21'. Mounting bars 104-105 also have a pair of facing semicircular recesses 109-110 for receiving and clamping the downstream ends 'of the coil springs 91 and 92.
The tubular ends 94 and 95 are formed by folding back a pair of integral flaps and cementing or by fus-ion, mola~ng etc... Although in the example the elasto-30 meric sheet is mounted to the coil springs 91 and 92 bythe tubular end sections, integral upstream tab portions or extensions 96 clamped between weight elements 98A and 98B and the integràl downstream tab extensio~ 106 clamp-ed between the mou~ting ba~ assembly coact with the tub-ular sections to stab~lize'the assembly to prevent sagg-.~.
-16~
ing under gravity or ~cceleration in the plane o~ -Lhe assembly shown in Figure 10. This fle~ible assembly is silent and inherentL~J cllc~less. Tne stress in the coil ~prings 91 and 92 is Yery low, even for large 5 fleæural deflection, so that fatigue is not a signifi-cant pro~lem. Moreover, no special handling or treat-ment or the materials or pre~ise talerances are requir-ed. Also, this assembly can oe used in the defrost nozzle.
It will be appreciated that all rubber or elasto-meric material vane-springs may be molded or otherwise formed to have the desired spring - mass characteris~ics described above and perform in air flow systems as des-cribed above, due regard being had for the effect of 15 temperature on rubber etc. Likewise, the composite metal-elastometer and spring properties may easily be utilized to practice the invention. The mass or weight required to achieve a desired spring-mass system can be molded into the end of the vane, and the mounting 20 assembly can also be integrally molded into the unit.
While I have shown and described preferred embodi-ments of my invention, it will be appreciated that var-ious modifications and adaptations of my invention are possible and it is intended that such modifications and 25 changes as would be obvious to those skilled in the art be emcompassed within the spirit and scope of the claims appended hereto.
Since in the preferred embodiment of the invention, the cross-sectional area of the oscillatory impingement ele-ment is smaller than the cross-sectional area of the duct to permit free movement thereof without impacting on any element, it is completely silent, consumes no ' ~ ~'7~
power and does not introduce any significant pneumatic impedaIlce and thereby does not unduly load the impeller or blower motor in the defrost unit.
Referring ~o FiO~ure 10, t~e duct or channel of an automobile heater/air conditioning s~stem is indicated as supplying air to a no2zle 21' which inco~porates a further modified form or oscillating vane constituted by the coil spring-elastomeric vane assembly 90, the de-tails of whic~ are illustrated in Figures 11-14. In ~his emboidment, a pair of spaced coil springs gL and 92 '(the dimensional parameters are shown in Figure 14 for a typical application), which are embedded in tubu-lar end sectio~s ~4 and gs of a thin sheet 93 or elas~ic or elastomeric material, such as rubber. The upstream end of tab 96 OL elastic vane go is clamped between 2 pair of weight elements 98A and 98B, which have a pair of semi-circular recesses 100 and 101 in their fac~ng edges for receiving and clamping the upstreæm or oscil-lating end of coil springs 91 and 92. The downstream 20 end or tab 106 of elastic vane go is secured between a pair of mounting bars 104-lOS r~hich are used to secure the downstream end 106 of the vane assembly to the spaced walls 107-108 of nozzle'21'. Mounting bars 104-105 also have a pair of facing semicircular recesses 109-110 for receiving and clamping the downstream ends 'of the coil springs 91 and 92.
The tubular ends 94 and 95 are formed by folding back a pair of integral flaps and cementing or by fus-ion, mola~ng etc... Although in the example the elasto-30 meric sheet is mounted to the coil springs 91 and 92 bythe tubular end sections, integral upstream tab portions or extensions 96 clamped between weight elements 98A and 98B and the integràl downstream tab extensio~ 106 clamp-ed between the mou~ting ba~ assembly coact with the tub-ular sections to stab~lize'the assembly to prevent sagg-.~.
-16~
ing under gravity or ~cceleration in the plane o~ -Lhe assembly shown in Figure 10. This fle~ible assembly is silent and inherentL~J cllc~less. Tne stress in the coil ~prings 91 and 92 is Yery low, even for large 5 fleæural deflection, so that fatigue is not a signifi-cant pro~lem. Moreover, no special handling or treat-ment or the materials or pre~ise talerances are requir-ed. Also, this assembly can oe used in the defrost nozzle.
It will be appreciated that all rubber or elasto-meric material vane-springs may be molded or otherwise formed to have the desired spring - mass characteris~ics described above and perform in air flow systems as des-cribed above, due regard being had for the effect of 15 temperature on rubber etc. Likewise, the composite metal-elastometer and spring properties may easily be utilized to practice the invention. The mass or weight required to achieve a desired spring-mass system can be molded into the end of the vane, and the mounting 20 assembly can also be integrally molded into the unit.
While I have shown and described preferred embodi-ments of my invention, it will be appreciated that var-ious modifications and adaptations of my invention are possible and it is intended that such modifications and 25 changes as would be obvious to those skilled in the art be emcompassed within the spirit and scope of the claims appended hereto.
Claims (31)
ROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an air flow system having a source of air under pressure flowing through a channel coupled to an outlet element is issued in a sweeping air stream pattern the improvement comprising a resilient vane oscillator element in said outlet element, said resilient vane having a longitudinal axis, and means securing the downstream end only of said vane in fixed relation to said outlet element with the upstream end of said resilient vane being free and oscillatable, solely by air flow, between a pair of extreme positions, said extreme positions being short of contacting said outlet element and said channel and causing the air to issue in a sweeping air stream pattern from said outlet element.
2. The invention defined in claim 1 wherein said resilient vane includes means for limiting the bending thereof to an axis transverse to the direction of air flow.
3. The invention defined in claim 2 wherein said means for limiting the bending of said resilient vane is constituted by a bend in the body of said resilient vane member.
4. The invention defined in claim 2 wherein said means securing said downstream end of said vane element includes a mounting assembly bar having a slot formed therein for receiving said downstream end of said resilient vane, said slot having the opposing facing corner edged thereof at the entrance way to said slot rounded and smoothed.
5. The invention defined in claim 2 wherein the edges of said resilient vane includes a body member polished to lengthen the life of said oscillator element.
6. The invention defined in claim 1 including a weight secured to the free end of said vane.
7. The invention defined in claim 6 wherein the end of said weight presents a flat surface transverse to the direction of air flow in said channel.
8. The invention defined in claim l wherein said resilient vane is constituted by a pair of spaced apart coil springs and a flexible sheet extending between and carried by said coil springs, respectively, and a weight member carried at the free end of said resilient vane.
9. The invention defined in claim 8 wherein said flexible sheet is made of an elastomeric material, a pair of tubes formed at each side of said flexible sheet, and one of said coil springs being located in one of said tubes, respectively.
10. The invention defined in claim 9 wherein said flexible sheet includes upstream and downstream tab extensions, said weight member being secured to the upstream tab extension and upstream ends of said springs, and said securing means fixing said downstream tab extension and the downstream ends of said springs together and to said outlet element.
11. The invention defined in claim 1 including means to capture said oscillatory element at a selected position in said outlet element to prevent oscillation thereof and cause air to issue from said outlet in a non-sweeping air stream pattern.
12. The invention defined in claim 11 wherein said means to capture said oscillatory element includes a friction stop, and lever means for adjusting said member to a non-oscillatory position.
13. The invention defined in claim 8 including an impingement member on the free end of said springs and wherein the rate of oscillation of said impingement member is related to the spring constant of said springs, the rate of air flow, and the weight of said impingement member.
14. The invention defined in claim 1 wherein said oscillatory element is in the shape of an inverted "T", the free end of the stem of said "T" being the sole point of support for said "T" in the air flow, and being downstream of the cross of said "T".
15. The invention defined in claim 1 wherein said oscillatory element is in the shape of an inverted "L", the free end of the stem of said "L" being the sole point of support for said "L" in the air flow and being downstream of the cross of said "L".
16. The invention defined in claim 1 wherein said oscillatory element is a steel spring and includes means for limiting the bending thereof to an axis transverse to the direction of air flow in said channel.
17. The invention defined in claim 16 including a weight member on the upstream end of said steel spring wherein the rate of oscillation of said oscillatory member is related to the spring constant of said spring, the rate of air flow and the weight of said weight member.
18. The invention defined in claim 16 wherein said spring in said oscillatory element is constituted by a pair of spaced steel coil springs, and a flexible sheet extending between and supported by said spaced apart coil springs.
19. The invention defined in claim 18 wherein said coil spring pair is embedded in the ends of said flexible sheet.
20. The invention defined in claim 19 wherein said flexible sheet is elastic.
21. The invention defined in claim 19 wherein said flexible sheet is rubber.
22. The invention defined in claim 20 wherein the upstream end of said oscillatory element is a weight element and the rate of oscillation is a function of the combined spring constant of said spring and said elastic sheet and the weight of said weight element.
23. The invention defined in claim 1 including an automobile defrost/defog system, said outlet element constituting an outlet for directing a sweeping stream of air upon the interior surface of an automobile window, said stream of air being swept back and forth across said interior surface at a frequency such that the wave length of the sweep is a short length of air stream between said nozzle and the edge of said interior window surface nearest said nozzle whereby mixing of said air stream with ambient air is reduced.
24. The invention defined in claim 23 wherein said resilient vane includes a thin resilient spring and a weight member rigidly coupled to the upstream end of said spring such that the frequency of back and forth oscillation is substantially determined by the weight and spring constant of said spring.
25. The invention defined in claim 23 wherein said resilient vane includes a pair of spaced coil springs, an elastomeric sheet supported on said coil springs and means weighting the upstream end of said springs such that the frequency of back and forth oscillation is substantially determined by the weight and spring constant of said coil springs.
26. The invention defined in claim 1 including structural formation on the body of said resilient vane oscillator element rendering same clickless during flexing thereof about a selected axis.
27. The invention defined in claim 23 wherein said air stream is swept at a rate such that the wave length is greater than the distance from said source to the automobile window.
28. The invention defined in claim 1, wherein said air flow system controls the air flowing into the passenger compartment of an automobile, and including means for causing said sweeping air from said source to sweep at a first sweep rate for an initial period of time, and, subsequently causing the air from said source to sweep at a different second sweep rate for a further time period.
29. The invention defined in claim 28 wherein said first sweep rate is higher than said second sweep rate.
30. The invention defined in claim 28 wherein said first sweep rate is lower than said second sweep rate.
31. The invention defined in claim 1, wherein said resilient vane oscillator element includes a pair of spaced springs and a weight member secured to the upstream ends of said spaced springs.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/030,794 US4250799A (en) | 1979-04-17 | 1979-04-17 | Sweeping air stream apparatus and method |
| US06/119,699 US4336909A (en) | 1980-02-08 | 1980-02-08 | Oscillating reed and method |
| US119,699 | 1980-02-08 | ||
| PCT/US1980/000368 WO1980002262A1 (en) | 1979-04-17 | 1980-04-09 | Sweeping air stream apparatus and method |
| US80-00368 | 1980-04-09 | ||
| US030,794 | 1987-03-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1175280A true CA1175280A (en) | 1984-10-02 |
Family
ID=27363723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000349839A Expired CA1175280A (en) | 1979-04-17 | 1980-04-14 | Sweeping air stream apparatus and method |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1175280A (en) |
-
1980
- 1980-04-14 CA CA000349839A patent/CA1175280A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |