US2119094A - Gas-heated laundry iron - Google Patents

Description

May 31, 193s. F. v. BROSTROM 2,119,094

GAS HEATED LAUNDRY IRON Filed April 24, 1955 2 sheets-sheet 1 ff I( HOST/30M l L// \37 V 5f A TTOH/VEYS May31,193s. Y Ev. BROSTROM 2,119,094

GAS HEATED LAUNDRY IRON Filed April 24, 1935 2 sheets-sheet 2 Argo/inem* Patented May 31, 1938 UNITED STATES PATENT OFFICE GrAS-HEA'IEDl LAUNDRY IRON Frederik Vilhelm Brostrom, Kingston-on- Thames, England 3 Claims.

This invention relates to gas-heated laundry irons primarily for domestic use of the kind having a tubular burner disposed Within a combustion chamber, the lower Wall of which is con- 5 stituted by the sole of the iron, the tubular burner being formed with a number of small apertures, having in some cases short burner or jet tubes secured therein, adapted to produce short flame jets for heating the said sole of the iron.

The invention has for its main object to provide an improved gas-heated iron of this kind which shall be highly efficient while being of simple and compact construction.

A further object of the invention is to provide improved thermostatic means for controlling the gas supply to such irons so that they may readily be maintained at the correct temperature for ironing purposes.

In order to utilize to the best advantage the manual labour and time of an operator employing a laundry iron heated by the combustion of gas supplied to a burner disposed within the iron, it is necessary that the operative surface of the iron be maintained at such a temperature that the maximum amount of moisture will be evaporated from the fabric being ironed at each stroke of the iron.

Most gas-heated irons of this kind however are such that the temperature of. the operative surface drops so quickly when damp fabrics are being ironed that the ironing operation must be interrupted until the temperature again rises to a suitable value.

The difficulty hitherto has been to Vestablish good combustion of a sufficient quantity of gas within the confined space of the combustion chamber of an ordinary gas-heated iron and a gas-heated iron of sufcient capacity for ironing damp fabrics has, therefore, been of comparatively large size and of clumsy construction.

Now the conditions for good combustion in the confined space of the combustion chamber of a gas-heated iron of the kind referred to are the admixture with the gas of as much primary air as possible, the supply of a very small surplus of secondary air to the combustion chamber and a rapid exhaustion of the products of combustion from the latter.

According to the present invention these conditions are ensured in a gas-heated laundry iron of the kind referred to by providing a chimney, preferably of substantial height, through which the products of combustion are adapted to be exhausted from the combustion chamber, re-

(Cl. 15S-23.1)

stricting the inlet of secondary air to said chamber and disposing the tubular burner in such relation to the secondary air inlet and the upper wall of the combustion chamber that said secondary air is caused to pass beneath the burner 5 to the flame jets and is precluded from owing directly from the inlet to the chimney.

The chimney induces a. draught through the combustion chamber and this, due to the restricted supply of secondary air which is avail- 10 able, produces a slight degree of vacuum within the said chamber serving to increase the amount of primary air drawn in by the gas, stream and admixed therewith. In this way the complete combustion of a considerably larger quantity 15 of gas can be effected in the confined chamber available in a laundry iron of compact construction than has hitherto been possible.

In order to prevent the temperature of the operative surface of the iron from risingv eX- 20 cessively when slightly damped or dry fabrics are being ironed or when the iron is temporarily placed upon a stand or rest, a thermostat device is preferably incorporated in the iron adjacent said operative surface and adapted to reduce the 25 quantity of gas being supplied when the said surface has reached a predetermined temperature, which may be one of a Anumber of temperatures to which the thermostat may be selectively set.

Two constructions of a gas-heated laundry iron 30 in accordance with this invention are illustrated in the accompanying drawings, wherein:-

Fig. l is a longitudinal vertical section, partly in e1evation,rof one formof iron provided with a thermostat device, 35

Fig. 2 is a plan view of. saidiron with some parts removed or broken away,

Fig. 3 is a vertical section taken on the line 3 3 of Fig. 1,

Fig. 4 is a rear elevation of the iron with the 4@ handle supposed removed, Y

Fig. 5 is a fragmentary sectional side elevation of another form of ironwithout a thermostatV device,

Fig. 6 is a sectional plan view thereof, taken 45 substantially on the line 6-6 of Fig. 5, and

Fig. 7 is a fragmentary detail view, partly in section, showing gas supply control means.

Referring to Figs. 1 to 4, it will be seen that the iron shown comprises a sole I, of the usual 50 substantially triangular outline in plan View, formed with a peripheral upstanding flange la of small height and a central longitudinally extending raised portion or rib 2 commencing adjacent the rear endv of. thesole and terminating 55 rsi' bend of a burner pipe I of substantially horse shoe shape having its ends flattened and slotted, as indicated at "Ia, in Fig. 2, and dtach'ably secured by means of screws 8 to the sole .I adjav cent the ends of the rear edge thereof.

A series of. apertures 9 is formed in the underside of each limb of the burner pipe 'I'at such points that the ame jets issuing therefrom are directed downwardly and inwardly, preferably at an angle of 30 to the vertical, towards the upper surface of the sole I, see Fig. 3.

The requisite mixture of' gas and vprimary air flows to the burner pipe 'I, from a mixing chamber disposed in the passage 3, by way of a conically tapering bore I 0"(Fig/l) formedaxially of the plug 4, a conically enlarging bore Illa formed axially of the extension 5, and the tube 6.

As will be seen `from- Fig. 1,` the mixing chamber is constituted by thespace comprised between the conical vwall of the bore- ID in the plug.. 4 and the front or outer surface ofa gas nozzle II the re'ar edge of which is pressed against an annular shoulder formed in the bore 3 by'means of the tightening up of the plug 4, the pressure being transmitted through ai tubjular spacer I2vr and a packing ring I3`both surrounding the front end ofthe nozzle, as shown. The rear edge of spacer I2 is taperedor bevelled offinwardly so that the pressure exerted thereby on the packing ring I3 serves to force this outwardly against Ythe wall of the bore 3.

Gas is injected across the mixing chamber into the mouth of the boreY I0 from a small aperture I4 forming the outlet from the nozzle II which, as shown in Fig. 1, has a somewhat flared inlet leading to the cylindrical b'ore or passage 3.

The gas stream traversing the mixing chamber entrains and admixes primary air therewith,`

said air having access 4to the mixing chamber through a lateral'4 aperture I 6in the spacer I2 and attaining to said'aperture through a vertical bore I'I-frmed'in the raised portionor rib 2 on the sole I.` The aperture I6Y is disposed `so'thatY the'primary air passing therethrough is delivered into the annular space surrounding the wall defining the bore II) forwardlyof the'mouth of saidY bore, which arrangementfensures .that the primary air will be entrainedv equally allround the gas jet, flowing over the edge of thelwallrefrred to into the bore IDL 'I'his'fensures-that there is no loss of velocityof' the gas stream passing through the Venturi-likepassage IB, Illa tothe burner pipe I, with a consequent preventionof lighting-back to the injector nozzleul I.

'It' is preferred to provide means for regulating, within limits,gtheamount of primary air en# tering the bore I'I and such means may comprise, as shown, a tubular plug I8 `screwed in the upper end of Vthe bore I1 and formed with anfenlarged laterally aperturedupper Y end overv whichl isV frictionally engageda cap I9Halso formed with lateral apertures, Rotation of thel cap I9 relatively to the Vplug I8, withinilimits defined bytherengage- Ingentlof the ends `ofga, notch 2 0 formedin the,

lower edge of the capwith a'radial pin 2| secured in the plug (see Fig. 1), will vary the extent to which the apertures formed in the cap and plug, respectively, are brought into or out of register.

Gas is supplied tothe passage 3 in the rib 2 of the sole I through a pipe or tube 22 engaged at its lower end in an inclined aperture 23 formed in the rib 2 adjacent its rear end, said pipe or tube extending parallel with the front wall of a chimney 24 of substantial height which is detachably engaged over an upstanding rim 24a, formed integrally with the rear end of a cover 25 secured over the sole I.

The space between the cover 25 and sole I constitutes-the combustion chamber of the iron and the lower edge 26 of the cover is adapted to rest directly on the raised periphery Ia, of the sole at its rear endwhile being spaced therefrom by a small amount at its front end so that the only access for secondary air to the combustion chamber is through'the narrow slot 2'I (refer also to the construction ofiron shown in Fig. 5) thus left between the-"front portion of theflower edge of the c'overr25and the sole I.

AsAWill be seen from Fig. 3, the burner pipe l is disposedwith its medial plane somewhat above the edge 26 `of the cover 25 and with its outer surface closely adjacent the inner surface of the saidcover; so that the secondary air is caused to flow through'lthe slOty 21,' inthe direction indicated by the arrows, beneath the burner pipe 'I' tothe -ame'jets' issuing from the apertures 9in the pipe while being' precludedfrom flowing directlyto the Achimney 24 under the 'action of the" draught produced'by' the latter.

The chimney 24' is of rectangular cross-section and its front wallextends substantially parallel with the rearwardly and upwardlyiinclined rear portion 'of'fai'handl bow 28 which is secured to the cover 25 and sole I by meansof'a bolt 29 andtalso by means ofthe plug I8 already refrerredV to,'1 suitable spacers 3U being interposed between the cover 25 and` the upper portion of therib 2 on the sole I. Such spacers 30 may be constituted by `bosses-cast Von the rib 2 iif desired, as willbe understood.

A, Vsuitable handgrip 3 Ig of wood Vor other heatinsulating material, is secured between the upper ends of the handle 'bow 28, which ends are connected'by a bolt 372 (Fig. 1) passing through the handgrip, andthe gas pipe or tube 22 is provided at" its upper end with a suitable rearwardly directed nipple 33'for the connection of a flexible gasvs'upplytube thereto. Y

A s Will be seen from Figs. 2 and 4, the chimney 24'is` formed with aside wallv 34 disposed in a vertical plane and of substantial height and a sidewall 34a also disposed in a vertical plane but of sin'alleheight, the upper ends of these walls being`V connected by a top.` wall constituted by a relatively short upwardly directed portion 35 connected'tothe wall'34 and a relatively long more steeply inclined'portion 35a connected to the wall 34a.'

.Apertures 36 are formed in the` shorter top wall portion-359i' the chimney 24 to allow of the escape of theproducts of combustion therefrom, thest'eeplyfiriclined wall portion 35a acting as a deecting surface'and the apertures4 being disposed so that the hot gases are 'directed away frmi the handle 2'8`l 3l and Atherefore'the hand employedtohoperate thevion. In the case where their@ is t@ Ybeiemplfiyedby.a light-handed person the chimney `2,4 would .be engaged, over the rim: 2 4aviorgi; the cover251in such a manner that theapertured wall portion V35'would bedispose'd (as shown) to the right of the handle, considered in the direction of the nose of the sole I in the plan view of Fig. 2. For left-handed persons the chimney 24 would be engaged over the rim 24a. in the reverse manner, as will be understood.

In order that the sole I of the iron may be kept automatically at a desired predetermined temperature, a thermostat is provided adjacent the sole and adapted to control the supply ci gas to the nozzle II. y

This thermostat comprises a rod 31 of a metal or alloy having a high coefficient of expansion, for example, magnesium or duralumin, disposed axially of the bore or passage 3 in the rib 2 of the sole I and coacting at its inner end with the nozzle II. At its outer end the rod 31 is secured in a threaded plug 39 which is threadedly engaged in the internally threaded aperture of a second plug 48 engaged in the threaded end of the bore 3. A packing ring 4I vis interposed between the head of the plug 4i) and the end of the rib 2 and a similar packing ring 42 is arranged around the plug 39 between, the base of a threaded counterbore therein and the inner conically countersunk end of an externally threaded collar 43 adapted to be screwed into said counterbore.

It will be seen that the plug 39 may be screwed in or out of the plug 49 for varying the extent to which the inner end of the rod 31 projects into the ared inlet of the nozzle II without danger of gas leakage occurring.

As indicated in Fig. 4, it is preferred to provide a suitable scale of temperatures on the rear wall of the cover 25 and to form the head of the plug 39 with a suitable pointer or indicator for co-operating with said scale, so that when the pointer is set to a particular temperature on the scale the thermostat is also set to reduce the supply of gas to the nozzle whenever this temperature is exceeded in the sole I of the iron.

' It will be understood that expansion of the rod 31 causes the inner end thereof to enter further into the nozzle II and thus reduce the effective area of the passage available for the gas flowing to the outlet I4 with a consequent reduction of the quantity of gas delivered to the burner pipe in a unit of time.

The pro-vision of the primary air inlet apertures below the level of the top of the chimney 24 ensures that no combustion products are sucked through said apertures and the fact that the control of the supply of gas by the thermostat is effected within the nozzle II ensures that the gas stream directed across the mixing chamber will always have the cylindrical form most advantageous for entraining primary air.

38, see Fig. 1, indicates apertures provided in the front end of the cover 25 to facilitate ignition of the gas jets issuing from the burner pipe 1.

Referring now to Figs. to '7, in which parts corresponding to those already described are indicated by like reference numerals, the sole I is here again formed with the raised periphery Ia. A raised portion 2 is formed substantially centrally of the sole I to add to the weight thereof ind the cover 25 carrying the chimney 24 is secured in place, together with the handle bow 28, by means of bolts 29 screwed into said raised portion 2.

The cover 25 is constructed in the manner already described to leave a secondary air inlet slot 21 but the burner pipe, while being disposed substantially in the same manner as the pipe 1 loop 44 fed from a short tube 45 disposed at the rear of the iron and bent upwardly to engage over an axial tubular extension 46 on the lower end of a cylindrical member 41.

As will be seen from Fig. 5, this member 41 is bored axially from its upper end to provide a mixing chamber 48 into which primary air is adapted to be drawn through lateral apertures 49 due to the projection of a gas streamaxially of said chamber from a nozzlev 59 screwed into the lower yend of a plug-cock casing 5I which is in turn screwed into the upper end of the bore in the member 41.

The gas stream is directed into the outwardly flared upper end of a conically widening passage 52 which extends from the base of the mixing chamber 48 axially of the extension 45 on the member 41 to open into the tube 45. It is preferred to secure the latter on the extension 46 by means of a set screw 53 adapted to serve at the same time as a stop for a screwed sleeve 54 capable of being adjusted longitudinally on the member 41 for covering more or less of the apertures 49 for the inlet of' primary air.

At its upper end the plug-cock casing 5I has secured therein a nipple 55 adapted toI have the end of a flexible gas supply tube engaged thereover and the passage of the gas from said nipple to the nozzle 56 is controlled by the plug-cock 56.

In order that the quantity of gas being burnt in the combustion chamber of the iron may readily be reduced from that corresponding to normal requirements to that which is merely sufficient to maintain the sole I at the required temperature when the iron is on a stand or the like or when dry or slightly moist fabrics are being ironed, the gas outlet passage leading from the cock 56 to the nozzle 50 is made of smaller diameter than the gas inlet passage leading from the nipple 55 to said cock and the latter is formed with a conical through passage 51 which is of larger diameter than the gas inlet passage at the end adapted to co-operate therewith while being of approximately the same diameter as the gas outlet passage at the end adapted to co-operate with this.

When the cock 56 is in-a position in which the smaller end of its passage 51 registers with the gas outlet passage leading to the nozzle 50 the latter receives its full normal supply of gas but when, as indicated in Fig. '7, the cock 56 is turned to a position in which the smaller end of its passage 51 is brought partially out of register with the gas outlet passage, the nozzle 50 only receives a reduced supply of gas sufficient to maintain the desired temperature of the sole I of the iron for so long as no considerable amounts of heat are abstracted therefrom.

As indicated, it is preferred to provide adjustable stops for limiting the movements of the cock 55, these stops comprising screws 58 threadedly engaged in lugs 59 formed on the plug-cock casing 5I and adapted to co-operate with a radially projecting pin 65 secured in the operating head of the plug 56.

By adjustment of the screws 58 itis possible to regulate the quantities of gas delivered by the nozzley 59 for each end position of the plug-cock and the latter may then be turned rapidly lfrom one position to the other as required it being understood that complete interruption of the gas supply is effected by means of another cock (not shown).

I claimzf 1. A gas iron comprising a sole having a central shown in Figs. l to 4,'is here constituted by ar over and secured to said ridge,` said cover having a peripheral Wall projecting downwardly from said top portion, a burner tube between said peripheral cover wall and said ridge, said burner tuberhaving a rearwardly projectingtubular gas and air admission plug, said ridge being provided with a longitudinal passage in the front end of which said'gasv and air admissionplug is secured, said ridge being provided with a gas inlet into said passage and with an air inlet into said passage, and .means within said passage for mixing the gas and air before entrance into the burner through said air and gasadmission plug.

2. A structure as specied in claim 1; together with a heat-expanded rod disposed longitudinally Within said passage and adjustably secured at its rear end, the front end of said rod being related =With said air and gas mixingv means to control the amount of gas admitted thereto according tothe temperature of the iron.

3*. A gas iron comprising a sole having a cenangiogetral longitudinalheat-retainingrridge upon its upper side, a cover having atop portion extend-v ing over andisecured to said ridge, said cover havinga peripheral. wallprojecting downwardly'.

from said top portionto provide a combustionchamber, at least the longitudinal portions of said peripheral wall being spaced upwardly from said sole to provide a narrow slitto admit secondary air, said cover having an outlet for products of combustion, and a gas burner in said combustion chamber having a burner tube substantially in contact with said longitudinal portions of-said peripheral wall of said cover to prevent an appreciable amount of the secondary air from passing between saidperipheral wall and said burner tube and short-circuiting to said outlet, said burner tube being spaced upwardly from said sole to permit said secondaryair to pass under said burner tube, said burner tube having gas discharge orifices positioned to direct :llame jets downwardly and inwardly through said secondary air and against said sole.

FREDERIK VILHELM BROSTROM.

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