CA2007046C - Proximity ventilated cooking system - Google Patents

Abstract

PROXIMITY VENTILATED COOKING SYSTEM

ABSTRACT

A proximity ventilated cooking system for interior use is provided with means for providing effective exhaustive ventilation to maintain in a variety of installations an air flow velocity adjacent the burners and throughout the exhaust system that has sufficient velocity to capture and carry to atmosphere substantially all of the cooking gasses, vapors and fumes produced in cooking, but insufficient velocity adjacent the burners to produce undesirable cooking and burner heat distribution, and where gas burners are used, interference with desirable flame patterns.

Description

"` ;~ 7046 ~OXIMITY VENrIT.~T~D COOKING SYSTEM

L3ACKGI~OUND OF TIIE INVI~N'l'ION
This invention rela-tes to apparatus and me-thods Eor provid.ing efEec-t:ive exhaus-tive ventila-tion for proximity ventilated cooking systelns.
In selE-vcntilated coolcing sys-tems, such as cooktops and grill raslyes with proximity ventilation, coolsing gases, vapors and odors ~lre drawn into an exhaust inlet and are exhausted into the atmosphere.
Usually, the exhaust inlct is loca-ted adjacellt tl-e cooking surface ancl is the inlet to a flow path which seria].].y includes a plenulll, a blower, an atsnospheric exhaust and intercorlnecting ductwork.. The flow path to the atmosphere norma].]y extends tllroug;h a wall or floor of the room in wllich tl)e cooking system~ i9 loca-ted.
Tlle blower is frequently made a separate unit from the res-t of the cooking a~paratus and is installed prior to the ins-tallation of the rest of thc ap~aratus.
The blower is providecl witll a pair of brackets which permit the selective moun-ting of -the blower to the floor for discharge either tllrough--tlle~wall or through-the floor, as re~uired by the installation. ;~
Because the blower is i.nstalled separately, it can be .
located for ease of ~ccess and to avoid the joists or studs, whicll can ~e a pro~lem i.n retroEit installations. Ior a tllrougll-tllc-floor exhaust, -the blower is securecd to the floor with the outlet ~.
extencdiny through the ~loor. Elo~ever, for a t~rough-the-wall installation, the blower is secured to the :~
floor with -tlle outlet of the blower extending hori.zontally. 'rlle ouLlct o~ the blower is connected to atmospllere by a flexi.~le ductwor]c which ext:ends through the wall to an e:~ternal exllaust ou~let. A~ter the ~lower i9 secured in place and conriec-ted to the atmospheric exllaus~ he self-ventilated cooking apparatus is set in plr-~ce over the ~lower and connected to tlle electrical service. rrhe selE-ventilated cooking , , ., . :

;2~ 7046 apparatus can have a Lull lleigllt plenurll, whi.ch can be made tllinller to accomlnc)c3a~e a full si~e oven, or to permit the installati.on of a full size oven where the cooking surface .is adaptecl for countertop installation, while still providing proximity ventilation of the cooktop. The ~low patll is completed by connectiJIg the blower and tlle plenum oE l:he range by means of a length oE flexible pipc, and ~lle blower is plugged into the self-ventilated coo]cing al~paratus and thereby tlle 1~ electrical system oE ~l~e al)paratlls. Such self- :
ventilated cooking syster~ls are disclosed in U.S. Patent No. 4,428,357.
The installati.on of such cooking sys-tcms in a building presents signj.r.i~c.lllt prc~blems. Tlle air flow ~::
path from the blower to atrnosphere varies ~idely from building to building in its leng-th and its effective resistance to air f].ow. In some build.i.ngs, the c~ir flow path may be long and toLturous while in o-ther buildings, the air flow patll rnay be short and free from restrictions. Such variations in tl~e air flow path have 3.imited t.he installation of such cooking systems, particularly wl!ere gas W~3 used -to provide hea-t for qrillincJ and cooking. Wllere the exhaust paths were short and free from restrictions, such systems provided too much air ~low at the cooking surEace and did not provide uniform cooking and heat distribution and, wllere gas heat was used, proper Elame formation and combus-tion. Where the exhaust paths were long or torturousl the s~steln provided too little air flow at the cooking surface and was inef~ective in capturing coolt.ing yases and vapors and in carrying grease particles ~o atmospllere. Variati.ons in the structure of buildings and in the lencJth arlcl complication oE tlle exllaust path between tllf! hlower and atmospllere tllrough the walls of the buil.d:ing could tllerefore produce ineEfective exhaustive velltilation.

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SUMM~I~Y OF TIIE: IWVli,`NTION
The inventioll provides proximity ven-tilated cookillg systems Eor i.nterior use witll means for .
providing effec-tive exhaustive velltilation~ By providing effective exhaustive ventilation, we mean mailltaining an air flow velocity adjacent the burners and througllout -tlle exhaust system that has sufficient velocity to capture alld carry -to atlnosphere substan-tially all of the cookincJ (lasses, vapors and fumes produced in cookil-g comes~i~les, such as mea-ts and vegetab].es, but i.nsuL~icient velocity adjacen-t the burners to produce undesirable cooking and burner heat distri~ution, an~, where gac; }~urners are used, interference with desira~.l.e flame patterns.
A proximity venl:ilated cooking system of the invention includes an upwardly f.icing cooking surface;
and an exhaustive ventilation me-lns Eor the upwardly facing cookin(~ surface. The exllaustive ventilation means includes a plenum, or. other air flow passage formillg means, having an entrance adjacent the upwardly facing cooking surface, a ~lower, or other air flow producing means, connected to the air flow passage-forllling means, an exhaustive duct forming an air flow passage from the bl.owcr or other air producing means to tlle outside of the building, and means or providing effective exhaustive ventilation at said upwardly facing cookinc~ surface ancl throu(~hout the exhaustive ventilati.on means.
q'he means for providing an e:Efective exhaustive venti.lation can include a restric-tion means in the air Elow patll of -the cooking apparatus providing an efEective air flow open:ing oE less than a predetermine~
cross-sectional area to limit tlle volume of air flow into the exhaustive ven~cilatio~ leans for installations in which the exhaustive duct has less than a predetermined effective l.engtll; and a reStrictiQn mod.ification means associated with said restriction means, the restriction means and the restriction modi-fication means cooperating to provide an effective air flow opening of increased cross-sectional area to permit an increased volume oE air flow into the exhaustive ventilation means for installations in which the exhaustive duct means has an effective length greater than said predetermined effective length.
The invention includes various means for providing effective exhaustive ventilation and an apparatus permitting effective exhaustive ventilation to be easily effected during installation. The presently preferred such means comprises a truncated conical annulus used as a restriction means removably fastened at a conically-formed inlet of a centrifugal blower ~y restriction modification means in the form of a spring fastener with a plurality of annulus engaging portions carried by the blower inlet and adapted to engage and removably retain the annulus in the blower inlet.
The invention provides a proximity ventilated cooking apparatus and an installation method adapted for a wide variety of installations while maintaining effective exhaustive ventilation, selective installation and mounting of the cooking apparatus and its component parts, and reduced operating noises and vihrations.
Other features and advantages of the invention will be apparent from the drawings and descriptions that follow.

BRlEF DESCRIPTION OF T~IE DR~INGS
Fig. 1 is a diagrammatic drawin~ of a proximity ventilated cooking apparatus ins-tallation to illustrate the invention;
Fig. 2 is an exploded view of a preferred embodiment of means Eor providing effective exhaustive ven-tilation in this invention;

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-4a-Figs. 3 and 4 are exploded views of further embodiments of means for providing effective exhaustive ventilation in this invention;

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`` ~0~7046 ~5--Figs. 5 and 6 illustrate still further means for providing effective exhaustive ventilation in this invention; (Fig. 5 comprises Figs. 5A-5D and Fig. 6 comprises Figs. 6A and 6B) Fig. 7 is a perspective view of an installation of the blower and means for providing e~fective exllaustive ventila-tion of E'ig. 2; and Fig. 8 is a perspective view of a com~leted grill range installation.

D _ CRIP~ION OF THE PREF~I~RED EMBODIMENTS
Fi~. 1 illustrates an installation of a self-ventilated ~rill range 10 within a building 100.
Although the invention is shown and described using a grill range as an example, the inven-tion can be incorporated into any prcximity ventilated cooking apparatus. The upwardly facing cooking surface 12 of the grill range is provided with an exhaustive ventilation means comprising an air flow producing means 20, preferably a centrifugal blower, an air ~low passage forming means, or plenum, 30 with an entrance 32 adjacent the upwardly facing cooking surface 12, and an exhaustive cluct 40 forming an air flow passage rom the centrifugal blower 20 througll the building walls 110 to the outside of the building.
In the installation of self-ventilating grill ranges, the exhaustive duct 40 passes through various walls 110 and floors 11 of the building and the exhaustive duct 40 can reach lengtlls of 60 feet. Long runs of exhaustive duct work 40 can reduce the air flow and air velocity at the upwardly facing cooking surface 12 and within the plenwn 30, blower 20 and exhaustive duct 40 and result in insuf~icient air flow at the cooking surface and witilin the e~haustive ventilation means to capture and carr~ cooking gases, vapors, greases and fumes to atrnosphere exterior of the building.
Wi-th the inven-tion~ the installed system is provided with a MeAns for providing effective :

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exhaustive ventila-tion. EEfective exhaustive vell-tilation provides an air flow velocity adjacent the burners of coolcing surEace 12 allcl throughout the exhaust system (20, 30, 40) that has sufficient veloci-ty to capture and carry to atmosphere substan-tially all of the cooking yasses, vapors, greases and fumes produced in cooking comestibles, such as meats and vegetables but insuEf.icient velocity adjacent the burners of cooking surface 12 ~o produce undesirab].e cooki.ng and heat dis-tribllti.oll adjacen-t the burners or where gas burners are used to interfere wi-th combustion and desirable flame patterns. An effective exhaustive ventilation includes a to-tal air flow of from about 300 CFM to abollt 350 CFM and preferably about 330 CFM and an a.i.r velocit~r in excess of about 1500 ft. per min. within the exhaustive ventilation means througllout the exll.lust system.
~igs. 2 througll G illustrate various m~ans for providing systems of tlli.s invention with eEfective e~haustive ventila-tion.
Fig. 2 is an explodecl view illustratiny a presently preferred means for providiny effective exhaustive ven-tilation in a cooking appàratus oE this invention. As shown in l~ig. 2, the means S0 for providiny effective e~llaustive ventilation is located at -the inlet 21 oE the air ~low producing centrifugal blower 20. Means 50 preferably comprises a restriction means 52 and a rcstriction modification means 54 at the blower inlet 21 deformably engaged to permit effective exhaustive ven.tilation to be easily effected upon installation. The restrict.i.on means S2 is an annulus Eorming an effective air E].ow opening 53 of less than a predetermined cross-sect:ional arca. The air inlet 21 oE the blower in thls elllbodilllent is a hole 55 oE a pre<1etermined cross-sccti.onal area formed by part 56 oE
the restr.iction modifi.cation means. The restriction modifica-tion means 54 also comprises a fastener 57 to retain the annullls 52 in a pos.ition surrounding the air - ~:

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- ~ ,: : ' ' - Z~ 7046 inlet openin~ 55 and reducing the cross-sectional area at the blower inlet.
~referably, part 56 forms the air inlet 21 with a ;~
truncated conical surface 56a and annulus 52 ls formed as a truncated cone~ rhe fastener 57 retains annulus 52 nested with:in the truncated conical surface 56a forming an air inlet openi.ng 53 of less than a predetermined cross-sec~ional area.
In this preferred embodiment, the area 55 of -the air inlet opening is c11osen to provide, witll the air flow producing c~pacity oE l)lower 20, effec-tive exhaustive ventilatior1 in install.ations where the -~
effecti.ve length of the exhaust cluct 40 is, for example, 30 to 60 feet, and the area 53 o~ the annulus 52 is cllosen to provicle, with tlle air flow producing capacity of blower 20, effective exhaustive ventilation in installations where tlle effective leng-t11 of the exhaust duct 40 is less tl~an 30 feet. Tl1e effective length O1l an exhaust du(t is de-ter1nined by addislg to its actual length an effective leng-t1~ for elbows, reducers and.ot11er air flow res1ricting portions of the exhaustive ventilation path.
To permit the ann~lus restriction meails 52 to be easily removed in installation oE cooking systems oE
this invention, -the restriction Illodifica-tion means 54 is provided a manually-operable, cleformable ~astening means 57. As shown in Fig. 2, -the truncated conical surface 56a o$ the air inlet 21 forms a plurality of openings 56b, and fastener 57 provides spring loaded projections 57a carried belild the truncated conical surface 56a to e:ctend through the openin~s S6b. The spring loaded projections 57a permit conical annulus 52, and other restr.iction means SUCII as a perforated plate, to ~e pressed into and to re-tained in place withill the truncated covered surface 56a and to be easily pu].led from wit11in the truncated conical surface S6a for installations witl- exllaust luc1:s have an effective length of over 30 feet. As indicated in ~ ;~0~70gL~

Fig. 2, the pluralit;,es of openiJlgs 56b are elongated and the sprin~ loacle~ projections 57a comprise a plurality of bent portions of -tlle spring wire fastener 57. In assembly, fastener 57 substantially surrounds the outside of the truncated conical surface 56a with tlle plurality of bent portions 5~/a projecting through -the plurality of openillcJs 56b.
As furtl-er shown in Fig. 2, par-t 56 of restriction modification means 54 and a coupLer 58 are fastened at the air inlet 21 by a plurali-ty of screw fasteners 59 engaging a plurality of tllreaded holes 60 at tlle air inle-t. r~he coupler 53 provides a flange 58a Eor engagement by a f]exible duct 26.
~lthoug}l Fig. 2 shows the means 50 for providing effective exhaustive ventilation as a restriction means 52 in the form oE a removable annulus, means 50 can take o-ther forms. ~s ShOWIl in Fig. 3, the means 50 for providiny effective exllaustive ventilation can comprise a perforated panel G1 ~!-, a restrictiorl means. The one or more fas~ellers 59 can removably hold the perforated panel 61 over the air il~et 21 and provide restriction modiEication ineans. ~s shown in Fig. 4, means 50 for providing effective e~llaustive ventila~ion can comprise as a restriction means a parle~ 62 formincJ an effective air flow opening 53 of less than a predetermined cross-sectional area, and the restric-tion modification means comprises at least one pre-scored knock-out portion 63 in said panel.
Figs. 5A-5D show a p]urality of otller means S0 for prvviding effec-tive exhaustive ventilation comprising restriction means removably ~astened to tlle outlet of a plenum 30 and located ~Idj~cent the air inlet 21 of -the blower 20. ~s shown in Fig. 5A, means 50 can comprise a removable panel 64 havirlg an opening 53 of less than a predetermined cross-sectional area and ~rovided with restriction modi~icat;on mealls 65 in the ~orm of a pre-scored removable panel to permit installation of sys~ems with effective exllaust duct lengths of over 30 . .

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_9_ feet. In the system shown in Fig. 5A, an air filt~r 66 can he provided at -tlle air inlet of the blower. If desired, the panel 64 may be xemovably fastened to air filter 66 to extend tl~e variation of the air flow restriction available Wi t]l the system shown in Fig. 5A.
Figs. 5B an~ 5C also show systems providin~
extensive variation in the availa~le effective exhaustive ventilation. Means 50 of Fi~. 5B shows a panel 67 having a plurality of pre-scored removable panels 68, 69, 70 surrounding opening 53. Fig. 5C
shows a means 50 for providing ef~ective exhaustive ventilation by adjusting t:he effcctive cross-sectional area of opening 53 as Lormed by the overlapping rectangular openillgs in a ~air oi panels 71 and 72 tllat may be moved with respect -to one another. As shown in Fig. 5C, eacll panel 71 and 72 forms one or more openinys 71a, 72a. The panels 71, 72 are movable wit}
respect to one another to provide, through the .
overlapping positions of their one or more openings 71a, 72a, an effective air flow opening 53 oE less tha a predetermine~ cross-sectional area. The panel~ are provided with means perlllittincJ tlle relative nlovemen-t of the pair of panels to modify their air flow restriction and provide an effective air flow opening of increased cross-sec-tional arecl. AS shown in Fig. 5D, the means 50 providing a restriction m~ans can also be panel 73 with one or more openinc3s 73a providing the effective air flow opening 53 of less than a predetermined cross-sectional area. The ouenings 73a of such a panel can be a plurali-ty oE perforations, a plurality of slots or other such openings.
It is no~ necessary tl-at the means 50 for providing effective exhaustive verltilation be located at the air inle-t of the blower. The means 50 can be located at other locations within the exhaustive ventilation means of an installation. For example, a means 50 oE the type ShOWII in r'i(Js. 5A through 5D

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` ~0t;770~6 ~.c3 , a panel SUCh as G9, 67, 71 and 72~ or 73) can be located in the plenum 30 adjacent its en-trance 32. The panel can be adapted to be carried by a removable air filter in the plenum cllamber and the effective restriction to air flow can be modified by fastening means to permit the removal of the panel from the air filter.
Figs. 6~ and 6B illustrate another means for providing effective exhaustion ventilatioll located at -the air outlet of a centri~ugal blower 20. As shown in Figs. 6A and 6B, means 50 comprises a restriction means 75 having a cup-shaped EOL-In with a tubular portion 75a and a bottoln pc~rtion 75~ forming an e~fective air flow opening 53 (Fig. 6B) of less than a predetermined cross-sectional area. 'rhe air outle-t 24 of sai~ blower 20 has a -tubular forlll an~ tlle cup sllaped restriction means 75 is adapted to fit over the tubular form of the air outlet. The reslriction means 75 is provided with restriction modification means 76 (Fig. 6B) comprising one or more pre-scored knock-out portions 77, 78 in the bottom portion 75b.
Figs. 7 and 8 illustrate a cooking apparatus and installation method oE tllis invent:ion. As.shown in Figs. 2 and 7, the air l)roducing blower 20 has been provided at its air inle-t 21 with means Eor providing effective exhaus-tive ventilation.
; As indicated in Fi~. 1, installing a proximity ventilated cooking appara-l us requires installing at a eooking location within tlle wal]s of a building a cookiny apparatus 10 l~avillg an upwardly facing cooking ~ surface 12 and an exllalls-tive vent:ilation means, or air ; flow circuit, including a plenum chamber 30 having an entrance 32 acljacent the cooking surEaee, a powèr ; driven blower 20 and an exhaust duct 40. In the invelltion, installation is accomplished by provicling an exhaust duct runninc3 Erom the cooking loeation through ~ the walls of the building to the outside of the .; .

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buildinc3 prepariny the ~ flow cireuit of the eooking apparatus to provide ef~ecti~ve exhaustive ventilation at said upwardly facillg cooking surfaee and througllout said exhaust duet, securing the ~ower driven blower to the building a-t said cooking location, eonneeting said exhaus~ duct to said power driverl blower, and securing the eooking apparatus in plaee at said eooking loeation. ~s indieated below, the exhaustive ventilation means is preferably modiEied by removal modifieation, or adj-lstlllellt of the means for providing effeetive exhaustive venti]a-tioll in the cooking apparatus.
- ~s sllown in Fig. 7 Ihe blower 20 includes a scro]l 22 which termillates in a tangential outlet 24 and is helcl in place by ~rackets 40 and 41 which are identical. ~l-tl~ough -~he air inlet 21 is shown Oll the right of outle-t 24 in Fiy. 7, air inle-t 32 ean be loeated on the left of outle-t 24 if desired. S;nee bracket ~0 is best illustrated, onl~ braeket 40 will be ~ deseribed bu-t -the descri~tion is apylieable to braeket 41. Braeket 40 is made up of a vertieal portion 44 ancl two foo-t portionsl 46 and 47 which are at rigllt angles -to por-tion 4~ and to eaeh other and are essentially equally spaeed from tl~e axis of tlle inlet oE the ; 25 blower. Braeket 90 may be plaeed with either foot portion 46 and 47 engagin~ floor 11 while maintaining essentially a eonstant alicJnment of the plenum ou-tlet and blower inlet. Ilowever since blower outlet 24 extends be~ond the pJalle o~ foot portion 47 it would therefore ex-tend through the floor ll if blower 20 is plaeed wi-th foot portion 47 engagincJ floor 11.
; When installirlg the blower 20 in a through-the-wall position, as illustrated, a hole is Illade through wall 12 to aeeommodate an outlet pipe 34. It should be noted tllat the ehoiee of the loeation of the hole in wall 12 is made witll reference to the loeation of studs 14 ancl to a lesser degree to the ehosen loeation of blower 20. The studs can ~e locatecl in a eonventional : ~ ., . : : , : .

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~7~:)46 manner. Tile locat.ion chosen for the blower will ~e made Wit]l respect to the location of outlet pipe 34, .
the plenum 30 and tlle joists 16. The joists can be located in a conventional manner. In a typical ins-tallation an expander 25 is used ~etween blower 20 and outlet pipe 34. Because blower 20 is connected to plenum 30 by means of flexible pi.pe 26, there is considerable flexi~ility in posi-tioniny blower 20 so that the blower can ~e secured to the jois-ts 16, or not, as desired. This -Elexibility of positioning also ; permits tlle maintaini.ng of suEficient clearances between the members to facilitate installation. To the ~. extent possi~le, llowever, a straight run of pipes 25, - 34 and e~haust duc-t 40 .is desirecl to minimi~e flow :~- 15 resistance. As illus-trated, screws 48 extend tllrough holes 49 at foot portion 4~ of -the ~racket 40 and are screwed into the floor 1l. ~racket ~1 is siniilarly secured.
The exhaust duct 40 is then run through -the walls i 20 (in referring to walls we include iloors and ceilings and roo~s) of tlle buildincJ. If the len~th of the ; exhaust duct has an effective lenyth in excess of 30 feet, the exhaustive ventila-tion means defining tlle air flow circuit is prepared to prov.ide efEective exhaustive ventil.ation. EEfective length can be determined by adding, Eor example, an effective lengtl of five feet for each elbow in a 6 inch exhaust duct and similar effective len~ths ~or other res-trictions.
~ In the installatioll of cooking apparatus such as that 30 shown in part in Figs. 2 and 7, the restrictive means, or anllulus 52, is pulled from the blower assembly 20.
Fastener 57, through its spring loaded projections 57a (Fig. 2) permits easy rellloval of -tlle restric~ion means 52.
With blower 20 securcd to floor ll and with outlet , pipe 34 in place, flexi~le pipe 25 is set in place to connect outlet 2~ with outlet pi~e 34. The end of exllaust duct 40 is tllen connecte(l to the outlet pipe :.
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34 'l'he blower 20 will then appear as illus-trated in E~ig. ~. I;'lexible pipe 26 is set in place on inlet 21 of blower 20 by placinc3 flexible pipe 26 over coupling 58. Alternatively, fl'exible pipe 26 can be installed a~ter the self-ventila-ted range is set in place.
'l'he cabinet ~0 of the self-ventilated range 10 will be set in place over the blower 20 and the sel-ventilated range will be connected to the electrical service in a conventional manner. Fig. 8 shows a range 10 wi-th an upwardly facing cooking sur~ace 12 where tlle inlet en~rance 32 to the proximi~y ventila-tion system is located in the -top of range 10 ~etween intercllangeable cooktops 84 and 85. Access door 86 which is located l~e]ow oven door 87 replaces the normal utensi] drawer and serves to prvvide the ~' necessary access for connectillg the flow path. A major portion of the exhaustive ventilation means is shown in phantom lines in ~`ig. 8 with a blower having its air inlet at the left of -the air outlet. Af-ter ranc3e 10 is set in place the access door 86 i9 opened to permit easy access to ventilation chamber Eor connectLng flexible pipe 26 to the b]ower 2() and plenum 30 to colnplete the exhaus-t flow pakh between inlet grill 32 and exhaust duct 40. Since blower 20 is firmly secured to the floor 11 and is physically connected to the rest of the range only by Elexible pipe 26, vibration and noise are minimized. The chamber at the bot-tom of range 10 is open at the back and bottom so that the range 10 may be set or slid over -the previously ~ 30 installed blower 20. Motor 28 of the blower 20 is ; enabled by plugging plug 29 (Fig. 7~ into the sel~-ventilated range's electrical system.
Although the installation method described above refers to removal of the annulus 52 of the presently preferred cookincJ apparat:us of tllis invention, installations of -the invention include the removal modi~ication or adjustment of the other disclosed ~.
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`" Z0~70916 embodiments oE the means 50 for providiny effective exhaustive ven-tilation.
No prior known system or method provides effective exhaust.ive ventilation for a wide variety of installations. U.S. Pateli~ No. 3,756,217 shows a self-cont~ined cooking apparatus with a variabl~-posi-tioned damper to cletermine air 1OW velocity and direct.ion at the plenum enkrallce and to close the en~rance to prevent back drafts of outside air into the 10 room. U.S. Patent No. 2,0~5,511 sl-ows a burner system for creating downdraft velltilatioll adjacent a burner including a varia~le damper below the buxner and between the burner and an exhaust fan~ U.S. Patent Nos. 2,~28,683, 3,128,g3~, 3,803,690, 4,253,796 and 15 4,456,033 show various other ventilating and fan apparatus. U.S. Patent No. 3,803,69Q, for example, shows a blower with a removable ring to improve fan performance. These referellces do not disclose cooking :~ systems adapted for use with exhaust ducts of variable length with means for providing effec-tive exl~austive ventilation.
~- . Alt}lough the description and drawings above illustra-te and describe preferred embodiments o~ the invention, the scope of the invesltion is limited only 25 by the.prior art and scope of the following claims:

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Claims (39)

1. Proximity ventilated cooking apparatus including a housing having an upwardly facing cooking surface, comprising:
an air flow circuit, including a plenum chamber in said housing having an entrance adjacent said cooking surface, a power driven blower communicating with said plenum chamber including an air inlet and an air outlet and operable for drawing air across said cooking surface and into said plenum chamber to collect smoke and cooking fumes, and duct means extending from said air outlet to atmosphere;
restriction means in said air flow circuit providing an effective air flow opening of less than a predetermined cross-sectional area to limit the volume of air movement into said plenum chamber for installations in which said duct means has less than a predetermined effective length; and restriction modification means associated with said restriction means, said restriction means and said restriction modification means cooperating to provide an effective air flow opening of increased cross-sectional area to permit an increased volume of air movement into said plenum chamber for install-ations in which said duct means has an effective length greater than said predetermined effective length.

2. The apparatus of claim 1 wherein said restriction means is located at the air inlet of the power driven blower.

3. The apparatus of claim 2 wherein said restriction means is an annulus forming said effective air flow opening of less than a predetermined cross-sectional area, said air inlet of said blower is a hole larger than said predetermined cross-sectional area, and said restriction modification means comprises fasteners to retain said annulus in a position surrounding and reducing the cross-sectional area of said air inlet.

4. The apparatus of claim 3 wherein said air inlet is formed with a truncated conical surface, said annulus is formed as a truncated cone, and said fasteners retain said annulus nested within the truncated conical surface forming the air inlet.

5. The apparatus of claim 4 wherein said truncated conical surface forms a plurality of openings and said fasteners are spring loaded projections carried by said truncated conical surface and extending through said openings to permit the conical annulus to be pressed into and fastened in place within the truncated conical surface and pulled from within the truncated conical surface.

6. The apparatus of claim 5 wherein the pluralities of openings are elongated, and the spring loaded projections comprise a plurality of bent portions of a spring wire substantially surrounding the outside of said truncated conical surface with said plurality of bent portions projecting through said plurality of openings.

7. The apparatus of claim 1 wherein said restriction means is located at the air outlet of said power driven blower.

8. The apparatus of claim 7 wherein said restriction means has a cup shape with a tubular side portion and a bottom portion forming said effective air flow opening of less than a predetermined cross-sectional area, said air outlet of said blower has a tubular form, said cup shape being adapted to fit over the tubular form of the air outlet, and said restriction modification means comprises at least one pre-scored knock-out portion in the bottom portion.

9. The apparatus of claim 2 wherein said restriction means comprises a perforated panel, and said restriction modification means comprises one or more fasteners to hold said perforated panel over said air inlet.

10. The apparatus of claim 2 wherein said restriction means comprises a panel forming said effective air flow opening of less than a predetermined cross-sectional area and said restriction modification means comprises at least one pre-scored knock-out portion in said panel.

11. The apparatus of claim 1 wherein said restriction means comprises a pair of panels, each panel forming one or more openings, with said panels being movable with respect to one another to provide, through the overlapping positions of their one or more openings, said effective air flow opening of less than a predetermined cross-sectional area, and said restriction modification means comprises means permitting the relative movement of the pair of panels to provide said effective airflow opening of increased cross-sectional area.

12. The apparatus of claim 1 wherein said restriction means comprises a panel with one or more openings providing said effective air flow opening of less than a predetermined cross-sectional area, said panel being adapted to be carried by a removable air filter in the plenum chamber, and said restriction modification means comprises fastening means to permit the removal of the panel from the air filter.

13. The apparatus of claim 12 wherein said panel is provided with a multiplicity of perforations.

14. A method of installing a proximity ventilated cooking apparatus at a cooking location within the walls of a building, said cooking apparatus having an upwardly facing cooking surface and an air flow circuit including a plenum chamber having an entrance adjacent said cooking surface and a power driven blower, comprising the steps of:
providing an exhaust duct running from the cooking location through the walls of the building to the outside of the building;
preparing the air flow circuit of said cooking apparatus by modifying a restriction means in the air flow circuit of said cooking apparatus to provide effective exhaustive ventilation at said upwardly facing cooking surface and throughout said exhaust duct;
connecting said exhaust duct to said power driven blower; and securing said cooking apparatus in place at said cooking location.

15. The method of claims 14 wherein said restriction means is modified by adjusting a movable panel.

16. The method of claim 14 wherein said air flow circuit is modified by removing part of said restriction means.

17. The method of claim 14 wherein the air flow circuit is modified by removing the restriction means from the air inlet of the blower.

18. Proximity ventilated cooking apparatus for use within a building, comprising:
an upwardly facing cooking surface; and an exhaustive ventilation means for said upwardly facing cooking surface, said exhaustive ventilation means comprising an air flow passage forming means having an entrance adjacent said upwardly facing cooking surface, an air flow producing means connected to said passage forming means, and an exhaustive duct forming an air flow passage from said air producing means to the outside of the building, and means for providing effective exhaustive ventilation at said upwardly facing cooking surface and throughout said exhaustive ventilation means, said means for providing effective exhaustive ventilation comprising restriction means and means for modifying said restriction means to provide effective exhaustive ventilation.

19. The apparatus of claim 18 wherein said means for providing effective exhaustive ventilation comprises a removable restriction means located at the air inlet of the air flow producing means.

20. The apparatus of claim 19 wherein said removable restriction means is a removable annulus forming an air flow opening of less than a predetermined cross-sectional area, said air inlet of said blower being a hole larger than said predetermined cross-sectional area of said annulus.

21. The apparatus of claim 20 wherein said air inlet is formed with a truncated conical surface, said annulus is formed as a truncated cone, and said annulus is retained nested within the truncated conical surface of the air inlet by spring loaded fasteners.

22. The apparatus of claim 21 wherein said truncated conical surface forms a plurality of openings, and said spring loaded fasteners are carried by said truncated conical surface and extend through said openings to permit the conical annulus to be pressed into and to retained in place within the truncated conical surface and pulled from within the truncated conical surface.

23. The apparatus of claim 22 wherein the openings formed by the truncated conical surface are elongated, and the spring loaded projections comprise a plurality of bent portions of a spring wire substan-tially surrounding the outside of said truncated conical surface with said plurality of bent portions projecting through said plurality of openings.

24. The apparatus of claim 18 wherein said means for providing effective exhaustive ventilation comprises a restriction means located at the air outlet of said air flow producing means.

25. The apparatus of claim 24 wherein said restriction means has a cup shape with a tubular side portion and a bottom portion forming an air flow opening of less than a predetermined cross-sectional area and at least one pre-scored knock-out portion in the bottom portion, and said air outlet of said air flow producing means has a tubular form, said cup shape being adapted to fit over the tubular form of the air outlet.

26. The apparatus of claim 19 wherein said restriction means comprises a removable perforated panel.

27. The apparatus of claim 19 wherein said restriction means comprises a panel forming an effective air flow opening of less than a predetermined cross-sectional area and at least one pre-scored knock-out portion in said panel to increase the effective air flow opening.

28. The apparatus of claim 18 wherein said means for providing effective exhaustive ventilation comprises a pair of panels, each panel forming one or more openings, with said panels being movable with respect to one another to provide, through the overlapping positions of their one or more openings, an effective air flow opening of less than a predetermined cross-sectional area and an effective air flow opening of increased cross-sectional area.

29. The apparatus of claim 18 wherein said means for providing effective exhaustive ventilation comprises a removable panel adapted to be carried by a removable air filter and forming one or more openings providing an effective air flow opening of less than a predetermined cross-sectional area.

30. The apparatus of claim 29 wherein said panel is provided with a multiplicity of perforations.

31. A proximity ventilated cooking apparatus comprising:
an upwardly facing cooking surface, a plenum chamber having an entrance adjacent said cooking surface, a power driven blower communicating with said plenum chamber including an air inlet and an air outlet and operable for drawing air across said cooking surface and into said plenum chamber to collect smoke and cooking fumes;
restriction means in said air inlet of said power driven blower providing an effective air flow opening of less than a predetermined cross-sectional area to limit the volume of air movement into said plenum chamber; and restriction modification means at said air inlet of said power driven blower engaging, but permitting the removal of, said restriction means from said air inlet for providing an effective air flow opening of increased cross-sectional area.

32. The apparatus of claim 31 wherein said air inlet of said blower is formed with a recession having a hole larger than said predetermined cross-sectional area, and said restriction modification means retains removably said restriction means in said recession of said air inlet by deformable engagement with said restriction means.

33. The apparatus of claim 32 wherein said air inlet is formed with a truncated conical surface and said restriction modification means comprises one or more projections to deformably engage and retain said restriction means within the truncated conical surface forming the air inlet.

34. The apparatus of claim 33 wherein said truncated conical surface forms a plurality of openings and said one or more projections are spring projections carried by said truncated conical surface and extending through said openings to permit the restriction means to be pressed into and fastened in place within the truncated conical surface and pulled from within the truncated conical surface.

35. The apparatus of claim 34 wherein the pluralities of openings are elongated, and the spring loaded projections comprise a plurality of bent portions of a spring wire substantially surrounding the outside of said truncated conical surface with said plurality of bent portions projecting through said plurality of openings.

36. The apparatus of claim 32 wherein said restriction means is an annulus.

37. The apparatus of claim 33 wherein said restriction means is an annular truncated cone.

38. The apparatus of claim 31 wherein said restriction means comprises a perforated panel.

39. The apparatus of claim 31 wherein said restriction means comprises a panel forming said effective air flow opening of less than a predetermined cross-sectional area and at least one pre-scored knock-out portion in said panel.