US2764664A - Apparatus for infra-red cooking - Google Patents

Description

Sept. 25, 1956 E. J. STEWART APPARATUS FOR INFRA-REID COOKING 2 Sheets-Sheet 1 Filed Oct. 26, l954 Sept. 25, 1956 E. J. STEWART 2,764,664

APPARATUS FOR INFRA-RED cooxwc Filed on. 26, 1954 2 Sheet s-Sheet 2 7 H I L 22 I III 1 I, I

wmzeyn United States Patent Ofiice 2,764,664 Patented Sept. 25, 1956 APPARATUS FOR INFRA-RED COOKING Edward J. Stewart, Harvard, Ill., assignor to Stewart In-fra-red, Inc., Harvard, 111., a corporation of Illinois Application October 26, 1954, Serial No. 464,805

2 Claims. (Cl. 219-35) This invention relates to that class of devices commonly known as cookeries or cookers wherein facilities are provided for heating foodstuffs by infra-red radiation.

Such devices have been previously known in the prior art and have been used more or less extensively in applications calling for rapid heating of food, particularly in such applications as the heating of pre-packaged sandwiches, frankfurters, and other food items of the sort customarily sold at concession stands and sandwich shops.

Prior-art devices of this class, however, have had definite limitations which have seriouslyrestricted their field of utility. For one thing, they have been dangerous to personnelsince the infra-red sources and the metal reflectors associated with them have in general been positioned where there was serious danger of contact with them during the operation of inserting or removing food.

Furthermore, the efiiciency of the prior-art devices has been substantially less than it should be, since, in order to reduce as much as possible the danger of contact with the infra-red sources, designers of such existing devices have placed the sources of heat radiation further from the food to be cooked than they should be. This construction has led to excessive dependence on expensive reflectors for focusing the heat in the cooking zones and has required use of excessively large cabinets.

Themain object of the present invention is to provide an infra-red cooking apparatus wherein the infra-red sources can be placed at optimum distance from the cooking zone to achieve maximum heat utilization and most efiicient cooking, while at the same time eliminating entirely danger of direct contact with the radiation sources or other dangerously hot surfaces by the persons using the apparatus.

In achieving this primary object, I have also achieved the secondary objects of providing an infra-red cooking apparatus that is substantially more compact than was possible with previous designs and which is not dependent on expensive, specially designed reflecting surfaces for successful operation.

I have illustrated a typical embodiment of my invention in the accompanying drawing, in which Figure l is an exterior perspective view of an apparatus for infrared cooking in accordance with my invention; Fig. 2 is a view of the Fig. 1 apparatus in vertical section, showing the parts in the position they occupy when the access door is fully opened; Fig. 3 is a sectional view in the horizontal plane, taken along the line 3-3 of Fig. 2; Fig. 4 is a fragmentary side view of the moving parts of the apparatus, the side of the cabinet being cut away and the access door being partially opened; and Fig. 5 is a view similar to Fig. 4 but showing the parts in the position they occupy when the access door is closed.

As may be seen from Fig. l, the illustrated embodiment of my invention is housed in a suitablerectangular cabinet 10, preferably made of sheet metal. Ventilatinglouvers 11 may be provided in the cabinet sides to permit easy circulation of air through the interior of the cabinet to prevent overheating.

It will of course be understood that thecabinet 10 may be provided externally with such surface decorations or advertising material as the nature of the intended application may dictate.

Referring now to Figs. 2-5, I have provided within the cabinet a ledge orbracket 12 extending inwardly of the inside wall of the cabinet and extending entirely around the cabinet at a level approximately half way between the top and bottom thereof. Bracket orledge 12 serves as support for agrill 12, which occupies the cooking zone and which has the function of supporting food for cookmg.

Suitably supported by theledge 12 and occupying a position in the cabinet generally below theledge 12 is a polygonally shapedmember 14, preferably formed of sheet metal and being provided on its inner surface with a high polish operative effectively to reflect infra-red radiation.Element 14 serves as a support for a portion of the infra-red sources which provide heat for cooking. These sources, which may be bought commercially, are suitable sources of infra-red radiation; I have illustrated, as the preferable type of such sources, the tubular quartz infrared bulbs now available on the market. In the illustrated embodiment, I have shown two ofsuch quartz tubes 15 mounted in suitable sockets 16 on the inner bottom surface of thereflector element 14.

The exact proportions and shape of thereflector element 14 will depend in considerable measure on the characteristics of the infra-red sources 15 and the number of such sources mounted in the reflector element. The

important point, for present purposes, is that thereflector element 14 should be so designed and proportioned as to place the infra-red sources 15 at the optimum distance from thegrill 13 to achieve, in combination with thereflector 14, optimum concentration of cooking heat over the surface of thegrill 13.

Carried on the rear portion of theledge 12, and mounted thereto by means of apiano hinge 17, is anupper reflector element 18 essentially similar in structure and shape to thelower element 14.Upper reflector element 18, however, is not fixed in position relative to the cabinet but is rockable onhinge 17.

A suitable number of infra-red sources 19, which may be similar tosources 15, is mounted insockets 20 on the inner top surface of theupper reflector element 18, preferably in aposition symmetrical with respect to the position ofsources 15 in thelower reflector element 14.

The foregoing remarks with respect to the shaping, proportioning, and dimensions ofreflector 14 apply also toreflector element 18, it being preferred that theelements 18 and 14 form, when in the position shown in Fig. 5, a symmetrical structure. As in the design of theelement 14,element 18 should be designed so as to. place the infrared sources 19 at the optimum distance abovegrill 13 for maximum concentration of cooking heat in the zone immediately above thegrill 13.

Suitableelectrical connections 22, including a manually controllablecurrent regulator 23, may be provided for supplying appropriate electric current to the infra-red sources 15 and 19. Such electrical connections are conventional and arenot part of the present invention; hence they have not been shown in detail.

The front of thecabinet 10 may be provided with a lower hingeddoor 24, suitably secured in a closed position by means ofcaptive screws 25 or other suitable .closure device. The function ofdoor 25 is to provide a convenient means of getting at the interior of the cabinet for purposes of cleaning and repair.Door 24 is not normally opened during routine use of the apparatus, and

closure members may accordingly be arranged so as to be releasable only by means of a servicing tool, such as a screw driver.

Abovedoor 24, and disposed so that its bottom edge is substantially at the same height asgrill 13, I provide amain access door 26, hinged to the front portion ofledge 12 by means ofpiano hinge 27. As may be seen from Figs. 2 and 3, thegrill 13 is exposed to access from the outside when thedoor 26 is fully opened. At the same time, opening ofdoor 26 causes theupper reflector element 18 to be rocked upwardly and backwardly onhinge 17, so as to separate the tworeflector elements 18 and 14, clam-shell fashion, leaving thegrill 13 available for convenient deposition or removal of food products while at the same time removing the infra-red sources 19 completely out of range of contact with the hands of the operator of the apparatus.

The action just mentioned is accomplished by means of two pairs of symmetrically disposedlevers 34, 35, 34a, and a. Thelevers 34 are pivoted respectively toflanges 33 and 33a, formed at the outer edges of thedoor 26. At their inner ends thelevers 34 and 34a are pivoted respectively to thelevers 35 and 35a, the upper ends of which are respectively pivoted to the sides ofupper reflector member 18, as is shown most clearly in Figs. 2, 4, and 5.

When thedoor 26 is pulled open by the operator, thelevers 34 and 34a bear against the inner edge offlange 12, as shown in Figs. 4 and 5, and rotate around that point as a fulcrum, in such action forcing thelevers 35 and 35a to rise and hence forcing theupper reflector element 18 to rock backward on thepiano hinge 17. When thedoor 26 reaches a horizontal position, as shown in Fig. 2, thelevers 34 and 35 reach a stable position, resting on the upper surface ofdoor 26 and the upper surface ofledge 12, and thereflector member 18 is thus held in raised position while the operator places food on or removes food from thegrill 13. When that operation has been completed, the operator may then liftdoor 26 to its closed position, as shown in Fig. 5, and theupper reflector element 18 will then return to its normal symmetrical position abovelower reflector element 14, as shown in Fig. 5. It will of course be understood that theelectrical cord 22 running to theupper reflector element 18 will be made of suflicient length to leave thereflector 18 free to move as aforesaid.

To permit convenient opening and closing of thedoor 26, I provide asuitable handle 32.

While I have in the present specification described in considerable detail a typical embodiment of my invention, it is to be understood that that description is exemplary only, and that many changes and variations in the structure shown may be made by persons skilled in the art without departing from the spirit of my invention.

I claim:

1. An apparatus for cooking by infra-red radiation comprising a cabinet, a radiation-source supporting means, said supporting means being provided with reflector means, means for mounting said supporting means at an intermediate height within said cabinet, a source of infra-red radiation carried by said supporting means above said reflecting means, whereby radiation from said source may be reflected upwardly from said reflecting means, a second radiation-source supporting means, said means comprising also second reflector means, means movably mounting said second supporting means within said cabinet operative to afford to said second supporting means a limited range of movement between one position whereat said first and second supporting means are in closely facing relationship and a second position whereat said second supporting means is retracted from said first supporting means, an infra-red source mounted on said second supporting means and disposed below said second reflecting means whereby radiation from said second source may be reflected downwardly from said second reflector means, food-supporting means disposed within said cabinet between said first and second supporting means, an access door in said cabinet, and coordinating means linking said access door and said second supporting means operative when said door is opened to move said second supporting means from its closely facing position to its retracted position, said coordinating means comprising a first link and a second link, one end of the first link being pivoted to one end of the second link, the other end of the first link being pivoted to said access door, and the other end of said second link being pivoted to said second supporting means, the cabinet being provided with abutting means adjacent said access door operative when said door is opened to act as a fulcrum around which said first link rotates in one direction during the opening movement of said door and in the opposite direction during closing movement of said door.

2. An apparatus for cooking by infra-red radiation comprising a cabinet, a first radiation-source supporting means, said supporting means being provided with reflector means, means for mounting said supporting means at an intermediate height within said cabinet, a source of infra-red radiation carried by said supporting means above said reflecting means, whereby radiation from said source may be reflected upwardly from said reflecting means, a second radiation-source supporting means, said means comprising also second reflector means, hinge means movably mounting said second supporting means within said cabinet operative to afford to said second supporting means a limited range of rotational movement, clam-shell fashion, between a closed position whereat said first and second support means are in closely facing relationship and an open position whereat said second supporting means is retracted angularly from said first supporting means, an infra-red source mounted on said second supporting means and disposed below said second reflecting means whereby radiation from said second source may be reflected downwardly from said second reflector means, food-supporting means disposed within said cabinet and positioned between said first and second supporting means whereby it occupies a space substantially midway between said first and second infra-red sources when said first and second supporting means are in closely facing relationship, an access door in said cabinet, said access door being disposed in a side of said cabinet opposite said hinge means, said access door having an open position and a closed position, a first link and a second link, one end of the first link being pivoted to one end of the second link, the other end of the first link being pivoted to the access door and the other end of said second link being pivoted to said second supporting means, said cabinet being provided with abutting means adjacent said access door operative when said door is opened to engage said first link and to act as a fulcrum around which said first link rotates in one direction during the opening movement of said door and in the opposite direction during closing movement of said door, whereby said second supporting means is moved from its closed position to its retracted position when said door is opened.

References Cited in the file of this patent UNITED STATES PATENTS 1,759,832 Banlf May 27, 1930 2,040,598 Cronyn May 12, 1936 FOREIGN PATENTS 470,791 Canada June 16, 1951

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