US3098922A

US3098922A - Domestic smoothing iron

Info

Publication number: US3098922A
Application number: US181325A
Authority: US
Inventors: John J Paxton
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-03-21
Filing date: 1962-03-21
Publication date: 1963-07-23
Anticipated expiration: 1980-07-23

Description

July Z3, 1963 J. J. PAxToN DOMESTIC sMooTHING IRON 2 Sheets-Sheet 1 Filed March 2l, 1962 4July 23, 1963 J. J. PAxToN DOMESTIC sMooTHING IRON 2 Sheets-Sheet 2 Filed March 21, 1962 JOHN J. PAXTON BY \|5 ATTO NEY FIG. 3

United Sites Patent O 3,093,922 DOMESTIC SMOOTI-IING IRON John J. Paxton, Amwell Road, Middlebush, NJ. Filed Mar. 21, 1962, Ser. No. 181,325 1 Claim. (Cl. 219--Z5) The present invention relates in genera-l to an ironing -device and, more speciiically, to an electrically operated hand smoothing iron for domestic use.

In order to attain optimum performance in a smoothing iron, it is desirable to maintain an even temperature at a selected level throughout the entire smoothing surface of Such an iron. lIt would be advantageous, from the standpoint of la user, to be able to achieve light weight, quick heating and low power demands in a domestic smoothing iron. However, these conditions lead to contradictory requirements in conventional designs for such irons. Even temperatures have called `for a relatively heavy sole plate with the result that quick heating has` required relatively high power demands. The invention has been devised to provide a smoothing iron for domestic use incorporating all of the desirable features outlined above.

A primary object of the invention is to provide a smoothing iron which maintains a selected, even temperature throughout its entire smoothing surface.

Another object is to provide a domestic smoothing iron which is light in weight and which will come up to operating temperature rapidly while making relatively low power demands.

A further object is to provide a hand iron which is easily fabricated of a minimum number of parts and wherein the operating elements are readily accessible and easily replaced.

The invention may be described brieily as an electric smoothing iron having a thin, metallic sole plate with an absorbing surface and a smoothing surface and a high thermal conductivity. The sole plate is heated by an elongated tubular quartz infrared lamp lying in la plane parallel to and vertically above the absorbing surface. A reflector is dis-posed above and to the sides of the lamp and xed to the sole plate adjacent the periphery thereof so as to establish an envelope enclosing a substantial portion of the length of the lamp between the reflector and the sole plate, the ends of the `lamp projecting through the reilector and outside the envelope, the enclosed portion of the lamp bearing such a relationship to the reiiector and the absorbing surface that the direct radiation and reiiected radiation from the lamp are combined to tend to provide an even distribution of infrared radiation throughout the absorbing surface wherein the radiation is converted into heat conducted through the sole plate for raising the temperature evenly throughout the smoothing surface. In order to regulate the temperature of the smoothing surface, a thermostat is mounted outside the envelope and is responsive to the temperature of the sole plate for intermittently interrupting the ilow of electricity to the lamp to regulate the emanation of energy from the lamp and maintain the temperature of the smoothing surface at a selected value. A main body is detachably secured to the sole plate and envelops the reflector and the projecting ends of the lamp as well as the thermostat and carries electrical contacts ymechanically secured thereto and electrically insulated therefrom, the contacts being disposed adjacent the ends of the lampy and being detachably electrically connected thereto for conducting electrical operating current to the lamp. Since it is essential to maintain the ends of the tubular quartz infrared lamp cool relative to the enclosed heating portion, vent means are provided in the body adjacent the projecting 3,098,922 Patented July 23, 1963 ends of the lamp to allow for the conduction of heat away lfrom the lamp ends.

lStill further objects will become apparent in the following detailed descritpion of an embodiment of the invention illustrated in the drawings in which:

FIGURE l is a longitudinal sectional view of a smoothing iron constructed in accordance with the invention;

FIGURE 2 is a plan view of the iron of FIGURE l;

FIGURE 3 is a transverse sectional view taken along line y3-13 of FIGURE 2;

FIGURE 4 is a diagrammatic transverse sectional view illustrating a specific reflector configuration;

FIGURE 5 is a diagrammatic transverse sectional view illustrating an alternative specific reector configuration; and

FIGURE 6 is a sectional detail taken along line 6 6 of lFIGURE l.

Referring iirst to FIGURES 1, 2 and 3, an electrically operated smoothing `iron is indicated generally at 1. Iron 1 is made up of a main body 2, a handle l3 fixed to the upper surface of the main body and a sole plate 4. Smoothing surface 5 of sole plate 4 performs lthe ironing operation when it is raised to proper operating temperature by internal heating means which will be more specically described hereinafter. Sole plate 4 is fixed to body 2 by means of screws 7. 'llhe flow of heat from the sole plate to the body is impeded by insulating means `8 placed between body 2 and sole plate 4.

The sole plate 4 is heated by an electrically operated source of relatively short Wave infrared radiation indicated generally at 10. In the preferred embodiment, the source 10 is a tubular quartz infrared lamp 1l (commercially available in the form of the General Electric Type T-3 lamp) o-f approximately 500 watts capacity. Such a lamp is small in diameter (about three-eighths of an inch) and produces a concentrated, narrow band of intense infrared radiation along a central portion 12. Ends 13a and 13b are provided for connecting the lamp to a source of electric current. Since the larnent of the lamp operates at a very hightemperature (about 40'00" F.) the infrared radiation is of a short wave length relative to infrared energy radiated by conventional electric heaters. Filaments of conventional lamps are operated at still higher temperatures since their primary function is to provide light rather than heat and are not economical vfor heating purposes. Unlike the conventional lamp, the infrared lamp will radiate most of the energy supplied to it in the form of intense infrared radiation making it an eilicient, :as well as abundant, source of heat.

A reilector 14 is provided to direct and aid in controlling the high intensity infrared radiant energy so that such energy is eifectively utilized to heat the sole plate 4 and raise the temperature of the smoothing surface 5. Reflector 14 -is placed about the source 10, above and to the sides of the source, and is iiXed at its edge 15 to sole plate 4 by wel-ding, brazing, riveting or like means, as near to the perimeter of the sole plate as is practicable. The ends 13a and 13b of the `lamp 1:1 project through the ends 16 of the reector leaving the central portion 12 of lamp 111 enveloped between the reflector and the sole plate. lInsulating grommets 17 aid in holding lamp 11 in place relative to the reflector while serving to impede the flow of heat through conduction to the reflector and through radiation toward the ends of the lamp. Thus, the reilector area stretches to encompass as much of the sole plate las possible within the envelope 13 enclosing the source 10.

Sole plate 4 is relatively thin (up to about one-eighth of an inch) and is fabricated of a material having a high thermal conductivity such as, for example, aluminum. In addition to smoothing surface 5, an absorbing surface `19 E is provided on the internal face of the sole plate within envelope 1S. The absorbing surface is preferably roughened and blackened so as to enhance its radiation absorbing ability. The reflector 14 is so shaped and the lamp 'll so located relative to the reflector that the reflected radiation is distributed throughout the entire absorbing surface A19. Because of the relatively short wave length of the infrared radiation, little radi-ation is absorbed by the surrounding air in envelope 18, the radiation being effectively projected by the source and directed to absorbing surface i9 in a manner similar to the Way in which light rays may be directed. The radiation is absorbed in surface i9 thus raising the temperature of the surface and causing heat to be conducted to the smoothing surface.

The employment of a narrow band source of intense infrared radiation makes possible the use of reflector shapes that will tend to even yout the distribution `of reilected radiation so that the combination of direct and reected radiation results in an even heating of the absorbing surface and an even temperature is attained rapidly throughout the smoothing surface. This feature cornbined with the practically instantaneous operation =of the lamp allows a rapid, ecient transfer 4of energy from the source to the smoothing surface. Since the sole plate is thin rand highly conductive, any small differences in ternperature throughout the area of the sole plate will be rapidly equalized to provide an even temperature throughout the smoothing surface.

While the reflector may assume any yone of a number of shapes, FIGURES 4 and 5 illustrate two simple congurations which may be utilized to control the distribution of ldirect rand reflected radiation in such a Way that said distribution is optimized.

FIGURE 4 shows a retiector 14a having 'a parabolic profile `over sole plate 4 with the lamp ylll placed slightly above the focus F of the reflector 14a. It will be understood readily that the longer the travel of a Iray of energy from source to absorbing surface, the weaker will be its intensity =at the absorbing surface. Hence, the direct radiation D at point X will be weaker than direct radiation D' at point L. However, the placement `of the lamp 11 relative to the reilector 14a causes the reilected rays R and R' to` diverge slightly and reinforce the Iweaker direct radiation, thus tending to even out the distribution of total radiation across the absorbing surface 19.

FIGURE l illustrates a reector 14b of a semi-cardioid-like configuration. Here, the total distance traveled by reflected rays and direct rays to a given point will be balanced for all points across the absorbing surface, thus optimizing the distribution of energy from source to sole plate. For example, the total of the length of reected ray R plus the length of direct ray D to point X is made to balance the total of the length of reected ray R' plus the length of direct ray D so that the total intensity of energy falling upon absorbing surface 19A at point X tends to equal the amount at point L.

Ihe reect'or may be fabricated of a highly polished material and is preferably constructed `of aluminum. Since the reflector is in direct contact with the sole plate, any heat which is incidentally absorbed by the reector will be conducted `directly to the sole plate; however, the greatest portion of the energy radiated by the source is directed against the sole plate in the form of radiation, both direct and reilected.

Source is energized by electric current supplied at plug 20 which is fixed to handle 3 and carried to the 'lamp ends through insulated conductors 21 which are fixed to clips 22. Clips 22 resiliently grip the ends 13a and 13b of the Ilamp 11 and are mounted upon and electrically insulated from the main body 2 by dielectric mounts 23 held in place by screws 24 ras shown in detail in FIGURE 6.

A thermostat 2S `of conventional design is placed in series with the lamp and senses the temperature of the sole plate through a strip 26 of high thermal conductit/ity. Strip 26 may be thermally insulated from the thermostat support 'arm 27 by insulating means 28. The thermostat is set by means of control knob 29 to interrupt the llow of electric current to the lamp when the sole plate is at a desired temperature. The rapid, eflicient transfer of energy from the source to the sole plate secured by the instantaneous operation of the lamp and the effective reflector system in combination with the thermostat which quickly senses the temperature of the sole plate assures that the selected temperature is accurately maintained at a constant level. Thus, the temperature of the smoothing surface 5 is regulated by a positive control. The positive control lobtained from the employment of a thermostat lis important from another standpoint. Continuous operation of the |lamp would soon cause the high intensity infrared radiation from the source to build up enough heat to melt the light-weight metallic components that constitute the primary elements of the device. However, the controlled, intermittent operation secured through the use of thermostat 2S combined with the eiicient reflector system ensures that enough energy is transferred from the lamp to the sole plate to rapidly heat the smoothing surface to a selected temperature while the emanation of amounts of energy from the source which could prove harmful is prevented. Thus, the thermostat makes practical the use of light-weight components where conventional irons would require heavier elements.

Window 30 is provided in body 2 so that the small amount of light emanating from the protruding length of the Ilamp adjacent end 13b is made visible. When the iron is first turned ron, the lamp will light instantaneously. When the sole plate is up to the temperature selected, the electricity will be cut off by the thermostat causing the lamp t-o shut olf. The user may observe this shut-off point which is an indication that the selected smoothing surface temperature has been reached.

'Ihe characteristics of the tubular quartz infrared lamp require that the ends be kept relatively cool (below 650 F). To this end, vent holes 31 are provided in body 2 to maintain the proper temperature in the vicinity of the lamp ends. Insulating grommets 17 also aid in preventing the temperature of the ends from rising to an undesirable value as outlined hereinbefore.

When it becomes necessary to replace lamp 111, screws 7 are removed. Main body 2 is lifted upwardly from the sole plate `4. Clips 22 will disengage from ends 13a and 413b as reflector :14, rmly attached to sole plate 4 holds the lamp in place. Thermostat 25 remains fixed to arm 27 of the sole plate, loops 32 being provided in electrical condutors 21 to allow for enough slack so that the body may be removed from the sole plate. The lamp may then be slipped out of engagement with the reflector.

The primary components of the device such as the sole plate, reector and main body may be easily and economically fabricated from light-weight sheet material such Ias, for example, aluminum, the necessity for heavy cast materials having been eliminated.

As a result of simplicity of design and the employment of light-Weight materials, an iron may be constructed as described above which will have a weight of less than twenty-four ounces as opopsed to conventional counterparts of up to approximately three pounds in weight. Temperatures in the range of about 200 F. to 550 F. are readily obtainable utilizing an intermittently operating lamp of 500 watts capacity as opposed to the 1000 watts demand of conventional domestic smoothing irons. Thus, the instantaneous power demand is reduced by a factor of two in the device of the invention and less stringent demands are made upon household electrical circuits. Furthermore, the instantaneous operation of the lamp combined with the etlicient and rapid conversion of the radiation from the source into heat at an even temperature throughout the smoothing surface results in the attainment of useful operating temperatures within an average of about twenty seconds after yfirst turning on the device.

It is runderstood that the above detailed description of an embodiment of the invention is provided by way of example only, and is not intended to restrict the invention. Modifications land changes in various details may be made -without departing from the true spirit and scope of the invention as set forth in the appended claim.

I claim:

An electrically operated smoothing iron comprising:

[A] a thin, metallic sole plate having an absorbing surface and a smoothing surface and a high thermal conductivity;

[B] an elongated tubular quartz infrared lamp lying in a plane parallel to and vertically above said ab sorbing surface;

[C] a reflector disposed above and to the sides of said lamp and xed to said sole plate adjacent the periphery thereof so as to establish an envelope enclosing a substantial portion of the length of said lamp between said reflector and said sole plate, the ends of said lamp projecting through said reflector and outside said envelope and the enclosed portion of the lamp bearing such a relationship to said reflector and said absorbing surface that the direct radiation and reected radiation from said lamp are combined to tend to provide an even distribution of infrared radiation throughout said absorbing surface wherein the radiation is converted into heat conducted through said sole plate for raising the temperature evenly throughout said smoothing surface;

[D] a thermostat mounted outside said envelope and responsive to the temperature of said sole plate for intermittently interrupting the ow of electricity to said lamp to regulate the emanation of energy from said lamp and maintain the temperature of said smoothing surface at a selected value;

[E] a main body detachably secured to said sole plate and enveloping said reflector and the projecting ends of said lamp;

[-F] electrical contacts mechanically secured to said main body and electrically insulated therefrom, said contacts being disposed adjacent said ends of said lamp and being detachably electrically connected thereto for conducting electrical operating current to said lamp; and

[G] vent means in said body adjacent said projecting ends of said lamp for maintaining said ends relatively cool in comparison to the portion of said lamp lying within said envelope.

References Cited in the le of this patent UNITED STATES PATENTS 1,032,267 Bastian July 9, 19.12 1,954,128 II-Ieyroth et al. Apr. l0, 1934 2,222,327 Walkup iNov. 19, 1940 2,223,331 {Roesch Nov. 26, 1940 2,397,236 Boyd Mar. 26, 1946 2,403,115 Olving July 2, 1946 2,778,913 Finlayson Jan. 22, 11957 2,844,699 Miskella July 22, 1958