Title:
Drying device
United States Patent 2369803


Abstract:
This invention relates to a drying device and particularly to a drying device comprising an electrically heated conductor for radiating infrared rays. It has been found difficult to dry various articles when the degree of humidity in the air is high and when temperatures are high as in hot...



Inventors:
Robert, Sardeson
Application Number:
US40811141A
Publication Date:
02/20/1945
Filing Date:
08/23/1941
Assignee:
PAKO CORP
Primary Class:
Other Classes:
34/266, 219/388, 392/414, 392/417, 392/418, 439/806
International Classes:
F26B3/30; F26B15/14
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Description:

This invention relates to a drying device and particularly to a drying device comprising an electrically heated conductor for radiating infrared rays.

It has been found difficult to dry various articles when the degree of humidity in the air is high and when temperatures are high as in hot weather. It is well known that the higher the temperature of the air the more capacity it has for holding moisture. At times the humidity is very high and at such times it is difficult to secure proper drying on various articles. While the present invention is applicable for many drying purposes and for drying many kinds of articles, it has been found in practice to be very useful and efficient in drying photographic films.

It is an object of this invention to provide a drying and/or heating device comprising an elongated casing, a heating member extending longitudinally of said casing for producing infra-red rays and a protective means for said member.

It is also an object of this invention to provide a drying device comprising a casing open at one side in which is carried a glass tube extending throughout substantially the entire length of the casing, in which tube is an electrically heated conductor preferably in the form of a helix and preferably of non-luminous character so that the infra-red rays are produced.

It is a further object of the invention to provide a drying device comprising an elongated casing having an open side and having a pair of tubes extending substantially throughout the entire length thereof, said tubes being made of glass or similar material and having extending therethrough electrical conductors preferably in convoluted form, a reflector being preferably disposed in the rear of said tubes for directing the radiant heat from said conductors outwardly.

Another object of the invention is to produce a drying and/or heating device having a heating means and a diffusing reflector associated with said heating means.

It is still further an object of the invention to provide a drying and/or heating device comprising an elongated heating element having convolutions, which convolutions can be arranged or proportioned to provide additional heat at certain points or zones to properly dry the article being operated upon.

It is more specifically an object of the invention to provide a drying device comprising an elongated casing having an open side and having disposed therein and extending throughout the length thereof one or more glass tubes, said tubes having electrical conductors extending therethrough preferably in the form of helices together with simple and efficient means for mounting said tubes and said casing.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in whichFig. 1 is a view in front elevation of the drying unit, some parts being broken away and others shown in vertical section; Fig. 2 is a view in side elevation of said unit as seen from the right of Fig. 1, a certain portion being broken away; Fig. 3 is a partial view in vertical section taken on line 3-3 of Fig. 1 as indicated by the arrows; Fig. 4 is a partial view similar to Fig. 1 some parts being broken away and others shown in vertical section, Figs. 3 and 4 being shown on an enlarged scale; Fig. 5 is a partial view similar to Fig. 1 shown on an enlarged scale; Fig. 6 is a top plan view of Fig. 5, some parts being broken away and others shown in horizontal section; Fig. 7 is a horizontal section taken on line 7-7 of Fig. 1 shown on an enlarged scale; Fig. 8 is a horizontal section taken on line 8-8 of Fig. 1 shown on an enlarged scale; Fig. 9 is a diagrammatic view showing the electrical connections; Fig. 10 is a view similar to Fig. 9 showing a modified arrangement; Fig. 11 is a view in side elevation partly in vertical section showing the heaters applied to a film drying rack; Fig. 12 is a view in vertical section taken on line 12-12 of Fig. 11 as indicated by the arrow; and Fig. 13 is a partial view similar to Fig. 11 shown on an enlarged scale.

Referring to the drawings, a drying device is shown comprising a unit including a casing 20.

While this casing could be of different forms and made of different materials, in the embodiment of the invention illustrated it is shown as made of sheet metal, being substantially rectangular in horizontal cross section and comprising the rear wall 20a and side walls 20b, the latter having out-turned narrow flanges 20c, said casing thus having an open front side. Casing 20 has adjacent its top and bottom in the sides 20b holes or knock-out portions 20d such as commoniy used in electrical outlet boxes. A conduit 21 Is shown connected to one upper side of casing 20 at one of said holes by the usual standard connectors 22. Suitable electrical conductors will pass through conduit 21 and will be later described. A reflector member 23 is provided and in the embodiment of the invention illustrated is illustrated as of the form in cross section shown in Fig. 8. Said reflector is of the diffusing type and has outwardly extending side portions and a central curved portion having its convex side directed outwardly, thus having a pair of angular recesses 23a. Reflector 23 is formed at each side with an outwardly extending and reversely bent flange 23b extending throughout its length at the front portion thereof, which flanges rsepectively extend and fit around the flanges 20c of casing 20. Reflector 23 extends throughout the greater portion of the length of casing 20 and to within a short distance of its upper and lower ends. Adjacent each end of casing 20 is disposed a plate 25 made of some suitable insulating material. To each plate 25 is secured a pair of clips 26. Said clips are made from a strip of resilient sheet metal and each has a vertically disposed intermediate portion 26a from one edge of which extends transversely an ear or lug 26b engaging plate 25 and secured thereto by the screw 27 having its head countersunk in the inner side of plate 25. A nut 28 is threaded on screw 27 and engages the opposite side of lug 26b. Screw 27 also acts as a binding post and has thereon a pair of nuts 29 between which is clamped one end of a conductor 30 of standard form and shown as having the usual insulating covering 30a. Clip 26a at the end opposite lug 26b is of semi-cylindrical form and extends around and is clamped to a cap member 31, said clip having its end portion brought into parallel relation with portion 26a, being connected thereto and clamped about member -3 by a headed and nutted short bolt 33. It will be seen that there are two clips oppositely and symmetrically disposed relatively to each plate 25, the clips at the top of the unit being on the upper side of the upper plate 25 and the clips at the lower end of the unit being on the bottom of the lower plate 25. The cap members 8 are of metal and of cup shaped form as shown in Fig. 4, and the same have secured therein by suitable cement or 'adhesive 34 the tubes 35. While tubes 35 might be made of various materials, in practice they have been made of clear glass. As shown in Fig. 4, caps 31 and tubes 35 extend through openings 25a in plates 25. The casing 20 as stated, extends beyond the ends of the reflector 23 and is at top and bottom equipped with a plate 36. This plate extends across the front of casing 20 and engages the adjacent end of reflector 23. Said plate 36 also extends across the adjacent end of casing 20 and has a short portion 30a extending vertically inwardly of said casing at the rear thereof, this portion thus extending downwardly at the top of casing 20 and upwardly at the bottom thereof. Casing 20 has lugs 20e extending inwardly therefrom adjacent its lower end portion, one of which engages the outer side of lower plate 25 and the other of which engages the inner side of plate 36. Screws 37 extend through the lower plate 36 into the lower or outer lugs 20e, thus holding said plate in position. Small brackets 40 are secured to casing 20, being welded or otherwise suitably secured at each side thereof. Each of said brackets has a portion of trapezoidal shape extending along the side of casing 20 and has an outwardly projecting ear or lug 40a. Said bracket has an inwardly projecting portion 40b extending along the inner side of upper plate 36 and said plate is connected to portion 40b by the screws 41. Electrical conductors or heating members 44 extend through the tubes 35 and while these might be made of various materials and arranged in various ways, in the embodiment of the invention illustrated they are shown as arranged as helices and in practice they have been made of an alloy known as nichrome. The convolutions of conductors 44 are arranged closer together for a considerable distance at the top and bottom of tubes 44 for a purpose to be later described. The ends of conductors 44 are secured by silver solder 46 or other suitable means in the ends of caps 31 and are thus electrically connected to the clips 26 to which conductors 30 are also electrically connected. Tubes 35 form a protective means for members 44 and yet do not interfere with the function thereof. One or more guard members 47 are preferably provided and these are illustrated as made from strips of resilient metal and of curved form having their convex sides directed forwardly, the same being provided with curved and bents flanges 47a adapted to engage around the flange 23b of reflector 23. These guard members 47 can thus be sprung and placed in position and will be retained in position frictionally. They can be moved up and down on reflector 23 and will remain in the position to which they are adjusted.

A small bracket 48 of general U-shape is secured to the rear of casing 20 by suitable bolts or rivets 49 and a supporting bar 50 extends through bracket 48, the same having a lower end 50a bent at right angles to engage the floor or other supporting surface. Casing 20 can be adjusted to various positions along bar 50 and can be held in place by the set screw 51 extending through bracket 48 and engaging bar 50.

The electrical conductors 30 will extend out through the conduit 21 to a suitable current supplying means. In practice if a 220 volt current is supplied the conductors 44 will be arranged in series as shown in Fig. 9, the lower binding posts 27 being connected by a conductor or bus bar 52. The supply line 53 will be connected to one of the upper binding posts 27 and the outlet or return line 54 will be connected to the other upper post 27. If 110 volt current is supplied conductors 44 will be connected in parallel as shown in Fig. 10. Bus bars or conductors 55 will conn' nect the binding posts 27 at the top and bottom of casing 20 and the supply line 53 will be connected to one of these bus bars, as the lower one shown in Fig. 10, while the outlet or return line will be connected to the other bus bar 55. In practice in one installation the dryer has been used for drying photographic films. In said installation a film drying rack or runway is used comprising parallel bars 60 shown as in the form of channels having their flanges directed away -e from each other. A chain 61 travels along the top of each bar 20, the lower run of the chain being shown as supported on the upper side of the lower flange of each channel 60. Chains 61 are intermittently moved. Supported upon the links 7 of chain 61 are the transversely extending rods or bars 62 which carry the film holding clips 63.

These clips 63 have film clamps 63a at their lower ends which engage and hold the upper ends of the depending films 64. Usually a weight clamp 5 65 is secured to the lower end of the film to hold it in vertical position. Bars 60 are shown as supported on vertically extending cylindrical standards 65. The drying unit comprising casing 20 is disposed at either side of the depending film 64, being supported by the bar 50 already described and by headed and nutted bolts 66 extending through the ears 40a and spacing thimbles 67 disposed between bars 60 and said ears.

In operation current is supplied to conductors 30 and thus to conductors 44. Conductors 44 are heated and in practice these conductors have been of a character to radiate infra-red rays at the temperature to which they are heated. Infrared rays are thus radiated and.these pass out at the front of casing 20 and are reflected by the reflector 23 to be directed outwardly at the front of casing 20. The heat is thus directed outwardly toward the films 64 and the films are dried as they pass the units comprising casings 20. The reflector 23 has been produced as a result of much effort. It will be noted that the reflector is of the diffusing type or of the type where the rays are diffused rather than focused or concentrated. The combination of a heating means with such a diffusing reflector is believed to be novel. The diffusing reflector produces a desired distribution of heat in the space in front of the device. Undue concentration of heat and excessively heated hot spots which have been found to occur with a converging reflector are avoided.

The heat is distributed to produce a good drying temperature in the zone through which the articles to be dried pass. In practice several units have been arranged in line at each side of the articles to be dried, which articles thus pass through the zone or lane formed by the units as indicated in Figs. 11 and 12. The guards 47 are provided to prevent the films 64 or weights 65 from engaging the tubes 35. They might be blown laterally by a blast of air and swung into the said tubes if guards 47 were not provided. Some water or moisture usually collects on the films about the clips 63a and the weight clamps 65. To insure that the films will be well dried at these upper and lower portions the conductors 44 have their convolutions closer together opposite said film portions so that more heat will be directed against said film portions. It will be seen that the convolutions of conductors 44 could thus be arranged closer together at certain points for drying parts of other articles where extra drying is necessary. The convolutions of said conductors can be closer together at some points and farther apart at some points to produce the desired .arrangement of heating zones. The device might be used therapeutically for applying heat to the body and more heat could be applied at different places along the body. The capacity for varying the heating effect of the heating element at different points is an important feature of the invention.

From the above description it will be seen that I have provided a very simple and highly efficient drying device. By the use of the device it has been possible to secure perfect drying of films even in the hottest and most humid weather.

The heat radiated by the unit has an unusual drying capacity and at the same time does not discharge as much heat into the room as would a gas flame or other similar drying unit. Not only has the drying been much more quickly and efficiently performed, but the room in which the device is located has been kept more comfortable for the operators. The clips 26 are made of resilient material and will flex to accommodate stresses which may be set up in the tubes 35 due to the heating and cooling. This flexing accommodates the expansion and contraction of the tubes 35 so that said tubes are not broken. Plates 25 are preferably made of asbestos insulating material, this acting to keep the heat away from the parts of the device beyond said plate. Plates 25 also form electrical insulators. The reflector 23 has a high reflecting outer surface and while this could be variously made, in practice it has been made of highly polished copper plate and a lacquered material. The unit is quite compact, comprises comparatively few parts and can be produced at a very reasonable cost. The same has been amply demonstrated in actual practice and found to be very successful and efficient.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of applicant's invention, which generally stated, consists in a device capable of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

S What is claimed is: 1. A drying device for films or other articles having in combination, an elongated housing of sheet material having rear and side walls, plates of insulating material adjacent each end of said housing and extending between said side walls, a plurality of glass tubes extending between and through said plates, cup-shaped members of conducting material fitting over and secured to the ends of said tubes, electrical conductors extending throughout the length of said tubes within the same and secured at their ends respectively to said cup-shaped members and adapted to be heated for producing infra-red rays, clips secured to said cup-shaped members at the remote sides of said plates, said clips being resilient and having lugs spaced from said tubes, binding posts secured in said plates to which said lugs are respectively secured, conductors secured to said binding posts and extending through the side of said housing and a reflector in said housing extending between said plates and disposed between said tubes and said rear wall.

2. A drying device for films and other articles having in combination, an elongated vertically disposed housing of sheet material having rear and side walls forming three sides of a rectangle in horizontal cross section, plates of insulating material extending transversely of said housing adjacent the top and bottom thereof, a reflector 5s extending between said plates within said housing having a central arcuate outwardly convex portion and flat side portions diverging outwardly to the front of said housing, thus forming spaced vertically extending trough-like recesses, 6o said side walls of said housing having narrow outwardly extending flanges, the sides of said reflector extending in front of and beyond said flanges and being reversely bent at an acute angle in the rear of said flanges whereby said reflector is held from outward movement, a guard member of arcuate form extending outwardly from the front of said housing and having its ends engaging the front of said reflector and bent to extend around the sides thereof so as to be held from outward movement, a pair of glass tubes extending through and between said plates in said housing disposed respectively in alignment with said recesses, clips secured to said tubes above and below said plates, electric conductors forming heating members disposed in said tubes and extending from top to bottom thereof and having their ends respectively secured to said clips and current-supplying conductors secured to one pair of said clips.

3. A drying device for films or other articles having in combination, an elongated housing of sheet material having rear and side walls, plates of insulating material extending across said housing between said side walls adjacent each end thereof, a pair of spaced glass tubes extending between and through said plates, members of conducting material fitting over and secured to the ends of said tubes, electrical conductors extending throughout the length of said tubes within the same and secured at their ends respectively to said members and adapted to be heated for producing infra-red rays, binding posts secured to said plates connected to said members, conductors secured to said binding posts for supplying current to said electrical conductors and a reflector in said housing extending vertically between said plates and transversely between the side walls of said housing disposed between said tubes and rear wall.

ROBERT SARDESON.