US2049711A

US2049711A - Drying oven

Info

Publication number: US2049711A
Application number: US706348A
Authority: US
Inventors: Robert R Lundy
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-01-12
Filing date: 1934-01-12
Publication date: 1936-08-04
Anticipated expiration: 1953-08-04

Description

R. R. LUNDY DRYING OVEN Aug. 4, 1936.

F'iled Jan. l2, 1934 4 Sheets-Sheet 2 3mm/M100 Woher? R andy plun www Il I NNN.. Nm zockmz.

Aug. 4, 1936. R. R. LUNDY DRYING OVEN med Jan. 12, 1954 l 4 Sheets-Sheet 5 Rober! l?. LundyV mwlzflw (MWTMMW Aug. 4, 1936.

R.R.LUNDY DRYING OVEN Filed Jan. 12, 1934 4 Sheets-Sheet 4 Patented Aug. 4, 1936 unirsi) srAT'ss PATENT @F-FCE atacan Darme oven Robert R. Lundy, South Bend, Ind.

Application January 12, 193i, serial No. 706,348

s claims. (ci. :i4- 19) This invention relates to improvements in drying ovens and particularly to drying ovens for performing a siccative action on objects of relativel`y`large size, and has for its principal object the provision of drying or baking ovens for performing a siccative action on single objects, or small groups of objects, individually.

A further object resides in the provision of drying or baking ovens which may be applied to one or more of a train of articles of manufacture moving on a continuous track, without affecting the siccative action on other articles in the train or interrupting the progress oi' the train.

A still further object of the invention lies in the provision of a drying or baking oven which completely encloses the article to be treated, in either a stationary or moving lposition-and prevents or retards the escape of heated, or otherwise treated, air or gas, from the oven during the siccative action, thus reducing the cost of the operation and preventing the deposit of dust or foreign matter on the wet surface of the object.

An additional object o! lthis invention resides in the provision of a drying or baking oven wherel by a siccative action may be obtained at a low operating cost vbecause of simplicity of article processing and oven handling equipment. Another object resides in the provision of a ,N drying or baking oven which completely encloses the article to be treated, in either a stationary or moving position, thereby maintaining a uniform temperature inthe enclosurejregardless of air conditions outside of the oven. v

Other objects and advantages oi' the invention will appear as the description proceeds. In the accompanying drawings I have illustrated one mechanical embodiment of the ideaof the invention and several slightly modiied forms, together with suitable methods of operation thereot. The drawings, however, are for the purpose of illustration only and are not to be considered as limiting the invention, the scope o!v which is to be .measured entirely bythe scope of the. subjoined claims.

In the drawings: v

Figs. 1a and 1b illustrate the application of my improved drying oven to a production line carrying objects such as automobile bodies;`

Fig. 2 is a vertical elevational view of on form of my improved drying oven;

Fig, 3 is a transverse sectional view taken on the line 3-3 of Fig. 2:

4 is afragmentary view similar toFig. 2

modiiled form of drying oven showing a movable l the time speciiled, the number of trucks ordinarily showing a somewhat modiiled form of the device of the invention;

Fig. 5 illustrates a somewhat diierent application of my improved drying oven to a production line carrying objects such 'as automobile 5 bodies,- from the application illustrated in Fig. l;

Fig. 6 is an end elevational view of a modified form of my improved drying oven and means for supporting the same;

Fig. 7 is a side elevational view of the drying 10l oven illustrated in Fig. 6.

Fig. 8 is a sectional view of a plant building showing a diierent application of my improved drying oven from that illustrated in Figs. 1a. and lb and 5; l5

Fig. 9 is an elevational view ofv a drying oven especially adapted for the application illustrated in Fig. 8;'and

Fig. 10 is a fragmentary elevational view of a hinged end or side therefor.

Referring to the drawings in detail, and particularly to Figs. la and 1b, the numeral i0 designates a continuous tracklaid on the floor li and upon which a series of trucks I2, supported thereon by suitable wheels or rollers I4 is adapted to travel.

Carried upon each truck is an article oil-manufacture such as an automobile body I5. In the application of the device as illustrated, the article i5 receives a coating s'uch as paint or lacquer in the spray booth Il and emerges from the booth with the coating in a we or solvent condition. This wet coating mustreceive siccative action' before the article can be handled and the next step oi' the manufacturing process-begun.

In order to accomplish the siccative action of these wet coated articles in the least possible time and at the minimum expense I have provided a plurality of special drying ovens 2li. The n umber of ovens required to carry out the method of my invention depends upon, and is largely determined by, three factors, namely, the length of time required for the siccative action, the speed with which the trucks carrying the coated articles -pass over the track, .and the number of trucks upon a given length of track. Having/Vl ilrst determined the maximum time required for the siccative action of the coating of the type under consideration, a length of track is laid oil', as illustrated in Figs. 1a and 1b', such that a truck carrying a coated article will pass from one end to the other, of the measured length of track in supported upon this length of track is then determined. To this number must be added enough reserve ovens to render the process continuous in placing the ovens over the articles and removing them therefrom in addition to a small number of spare ovens for use in case one or more of the ovens should develop mechanical troubles which would necessitate its temporary removal from service.

As further illustrated in Figs. la and lb, the

length of track specified above is provided with 1 an overhead trolley 22 embodying three electrical conductors 22a, 22h, and 22e carried by suitable supports 23 of insulating material. While I have illustrated and described an overhead, three-bar trolley, it is to be understood that the invention is in no way limited to this type of electrical conductor and that any other suitable type, such as a third-rail" type, may be used if desired.

At a distance above the above mentioned length of track, somewhat greater than twice the height of each of the drying ovens 20, I have provided a suspension track 24 secured to the ceiling 25 by suitable supports 23. This suspension track 24 has a generally rectangular cross section andis provided with a slot extending continuously along the under side thereof. At each end of the suspension track, I have provided a hoisting mechanism generally indicated at 21 and 29. Each hoisting mechanism comprises a pair of flexible cables 3i land 32 each connected at one end thereof to a member 34 which is similar in all respects to a short section of the suspension track 24. The cables 3| and 32 are carried over pulleys 33 and 31 respectively secured to the ceiling 23 and are engaged at their ends opposite the member u with the Vdrum or a hoisting windlass 33.- r

From the illustration andthe above description, it will be observed that when either member 34 is carried to its uppermost position it forms, in efl'ect, a continuous part of the suspension track 24. It will be further observed that the hoisting-mechanism 21 is so located as to be adapted to place one of the ovens 20 over the article I3 as the article emerges from the spray booth I3 and that the hoisting mechanism 23, is so located as'to remove the oven from the article at vthe end of the suspension track 24.

In Fig. 1a I have illustrated a platform 42 located abovethetrack l0 and supported from the ceiling or from the floor at such a height as to permit the ovens carried by the ysuspension track 24 to pass over it. in such positionthat `tion in Fig. 1a that this platform 42 terminates at a sufiicient distance from the booth I3 to permit ovens to be lowered between the booth and the, end of the platform and, that the platform extends a sufficient distance alongthe track to cover the open bottoms of two or more ovens at the same time. At this time it should also be understood that the trucks l2 are provided with solid or continuous platforms 44 which eectively close the open bottoms of the ovens 20 when the ovens are in operative position upon the trucks. A short trolley 43 is provided above the platform 42 so that the heating elements of the oven may be energized to preneet the ovens while they rest upon the platform 42.

baking oven illustrated therein comprises, in general, an elongated, substantially rectangular, boxlike structure having five complete walls and an open bottom. Preferably, the oven is composed of an inner structure 45 of sheet metal uniformly spaced from a similar outer structure 4 6 of the same material with suitable insulating material 41, such as asbestos fiber, compressed between the inner and outer structures. Suitable joints and bracing, such as the gusset plate 48, may be used to render the ovenrigid and durable. It is to be understood, however, that an oven comprising a single structure of sheet metal or other suitable material is within the scope of the invention.

The size and shape of my improved drying oven may also be altered to accommodate the oven to the size and shape oi' various articles of manufacture without in any way departing from the scope oi' the invention. Also, while I have illustrated an oven adapted to enclose a single relatively large article, such as an automobile body, it is to be understood that a group of two or more smaller articles, such as easings for electric refrigerators, may be enclosed within one oven at the same time.

Referring particularly to Fig. 2, it will be observed that I have provided on the upper portion of my improved oven a pair of lifting devices 50 and 50'. Each of these lifting devices comprises a stem 5| secured at its lower end to the top of the oven and provided with a thin portion adapted to travel through the slot in the bottom portion of the suspension rail 24. At its upper end each stem 5| carries a transverse pin 52 upon the opposite end portions of which is mounted a pair oi' rollers 33 in end to end relation adapted to travel upon the bottom portionI of the suspension rail 24, one upon each side of the slot. Referring to Figs. la and 1b.` it will be observed that these lifting

devices

50 and 50 are utilized in combination with the members 34 to lower the oven over the article and raise it fromthe article by the engagement of thel lifting devices with the members 34 as well as to support the oven on the suspension rail 24 during the return of the oven from the end to the beginning of the drying section of the track I0.

Each of my improved ovens is also provided with an individual heating device such as the electrical resistance heater indicated at I3 in Figs. la and 2. If desired. these heaters may be separately controlled as by the rheostat 31 and the internal temperature ofeach oven may be displayed by a temperature indicating device such as the thermometer 30 during the entire siccative action. It is also within the scope of the invention to apply automatic control devices to theA heating elements of these portable ovens to automatically maintain a predetermined temperature or series of temperatures during the siccative action. y

. The numeral 32 indicates an electric fan which -I have illustrated as let into one end of the oven and which isr operative to circulate the air or other gas contained within the oven, about the article which is being dried, or may force air from outside the oven into the oven if desired.

While, for the sake of clearness in the draw` ings, I have shown the oven heating device l5 located at a distance from the fan 42, it is to be understood that the heating element may be, and preferably is, combined with the fan, if a fan is Referring now to Figs. 2 and 3, it will be obused served that the form oi my improved drying lor rn'rig. 2 1 have also muetreted a vent s rm- 75 erwise than by heating it. If a fan is used, the

air humidifier or drier or filter 'l0 is preferably disposed between the fan 62 and the heating element 55 but may be located in any part of the oven without departing from the scope of the invention.

Referring back to Fig. 2, it will be observed that I have provided'suitable electrical connections and conductors for connecting the trolley 22 with the various electrically operated devices included in my improved oven. The numeral 12 generally indicates a trolley harp comprising a handle or supporting portion 13 and a contact carrying block 14. The contacts, not illustrated, carried by the block it are connected to exible conductors 15 which are led through the upper portion of the oven and secured thereto by means of suitable insulators Tl. From the insulators il the co uctors are led to the rheostat, the heating eement, the fan, and any other electrically operated device contained within the oven.

It will be noted that the exible portions of the conductors l5, between the block 14 and the insulators il, are of suiiicient length to permit a considerable latitude of movement to the trolley harp 12. The trolley harp handle 73 is detachably secured to the oven to hold the contact block in contact with the trolley 22 by means of a bracket 00 secured to a side of the oven. Referring to Figure la it will be observed that the harp 'i2 is disconnected from the trolley 22 at the time the oven is first lowered over the wet coated article but may be connected as the oven moves along with the truck I2 by manually inserting the handle i3 in the bracket 00.

In Figs. 5, 6, and 7, I have illustrated a somewhat modifled form of drying oven and a diderent manner of handling the same from that iilustrated in Figs. 1a, lb, 2, and 3. In this modi- 'ed form of the invention, instead of having trucks which run upon tracks mounted on the floor, I utilize platforms carried upon roller conveyers located at each end of the drying line, suspension tracks for supporting the ovens, and platforms during the drying or siccative process and returning the ovens from the end to the beginning of :the drying line, a chain conveyor' for propelling the ovens and platforms along the drying line, and interlocking elements acarried by the ovens and platforms to latch the platforms to the ovens during the siccative process.

In Fig. 5, I have illustrated an alternative manner of handling the ovens from that illustrated in Figs. la and lb. In this alternative manner, the objects of manufacture such as the automobile bodies as indicated at i5 are carried upon iiat platforms-00 and emerge from the spray booth (not illustrated in this figure) upon a roller conveyor |00 mounted on the i'ioor at the beginning of the drying line. At the end of the drying line is a similar roller conveyor |0| and between the two roller conveyors is a chain conveyor |03. overlying the chain conveyor and extending somewhat beyond each end thereof are a pair of suspension tracks |05 and |06 of I-section shown in end view'in Fig.'6. These tracks may be supported from the floor orvthelceiling by suitable .means such as the vertical hangersj Immediately above the suspension tracks,V

|05 and |06 at a vertical distance thereabove somewhat greater than the height of the drying ovens yis a second pair of suspension tracks indicated at |24 also secured to the ceiling as by hangers 09. A tracks is a hoisting device generally indicated at |21 and |20. Each hoistingv mechanism comprises two pair of flexible cables as indicated at |3| and |32, each cable/of each pair being connectedat one end thereof to a member |34, thesey members being similar in all respects to a short` section of the suspension tracks. The` cables are carried over pulleys as indicated at |36 and |31 secured to the ceiling |25 and are engaged at their ends opposite the members |34 with the 4drums of the hoisting windlasses as indicated at From this description, it will be observed that the members |34 may be moved by means of the hoisting mechanisms from one to the other of two operative positions in which they constitute a continuation of the track |06 or the track |24 and that by means of these members and the associated hoisting mechanisms the ovens may be shifted from the upper to the lower suspension tracks at the beginning of the drying process and from the lower to the upper track at the end of the drying process. During the drying process, the ovens are movedalong the lower track by the chain conveyor |03 and at the end of the process the ovens may bereturned manually or other- Y/wise valong the upper track |24.

The hoisting mechanisms overlie the respective roller conveyors |00 and |0| so that the platforms 94 are picked up from and set down on the rollers at the beginning and the end of the drying process. The platforms are not returned with the ovens but carry the' articles on to the end of the production line, of which the drying or siccative process constitutes a part, and are re turned to the head of the .production line.

In combination with the above described method ofhandling the ovens, I have provided a somewhat modied form of oven |00 particularly illustrated in Figs. 6 and 7. It is to be understood, however, that the diierent ovens illustrated and described are completely7 interchangeable and may be adaptedv to the different methods of handling by simply installing the proper carrying and current supplying devices.

The oven |00 illustrated in Figs. 5 and 6 preferably comprises an inner and outer wall structure with insulating material betweenthe two walls as illustrated in Fig. 3. In addition to the construction illustrated in Figs. 2 and 3, the oven |00 is provided with side walls ili which slope outwardly from. top to bottom to provide a space between the lower edge of each side wall and the adjacent edge of the platform 9d. These spaces may be closed bymovable closure members |02 .secured to the end walls of the hood by pivoted links idd and |55.

and a motor |63 for operating the fan. I have also provided ducts |54 for conveying the heated At each end of the suspension air from the heater |55 to the central portion of the oven. A vent |65 is provided in the upper portion of each oven to permit the escape of air therefrom.

For\purposes of carrying the empty oven or the oven and platform and article during the siccative action, I have provided carriers |10 secured to the oven on the upper portion of the sides thereof and containing rollers |12 which run upon the tracks |06 or |24, there being two such carriers on each side of each oven.

In order that electric current may be supplied to the oven during the siccative action or the preheating period, I have provided a side bracket adapted to support a handle |13 provided at its upper end with a block or trolley |14 adapted to contact an electrical conductor |22.

Referring to Fig. 6 it will be observed that 'each of the platforms 84 is provided at its ends with hooks |84 and that each of the ovens |40 is provided at each of its ends with a substantially U- shaped bar |85 pivotally secured to the oven by brackets |86 and terminating in bent-over ends |81 adapted to engage the hooks |84 to releasably secure the ovens |40 to the platforms 84 so that the oven, platform and article may be picked up as a unit by the hoisting mechanism and moved as a unit along the lower suspension track during the siccative action.

The method of operation of the device is substant'ially as follows: as each wet coated article emerges from the spray booth |8 an oven is low- 'ered over the article and permitted to rest upon the platform carrying the article thus together with the platform, forming a ltight enclosing space only slightly larger than the article. The trolley harp is then connected to the trolley by inserting the handle in the bracket. The heating element and fan are thereby energized and the siccative action proceeds for the specifled length of time. At the end of this time, or when the trolley harp has reached a point adjacent to the end of the trolley the handle is removed from the bracket and the oven is removed from the article by the hoisting mechanism and returned along the suspension track to the proximity of the spray booth |8. As the oven rests above the platform 42 the air within the oven may be p'reheated preparatory to repeating the above cycle.

It will be understood that while in general, uniform` drying conditions will be maintained in all of the ovens, the drying conditions in any individual oven may be manually or automatically varied if desired to meet particular siccative requirements. V

In Figs. 8 and 9 I have illustrated still another method of handling my improved drying ovens and an oven and platform specially adapted to this last method.

In Fig. 8 I have illustrated a somewhat different type of industrial building from that illustrated in Figs. la, 1b, and 5. In the building illustrated in Fig. 8 I have shown a floor 2'|| and a ceiling 225 but have shown the central portion of this building extended upwardly to accommodate a traveling crane generally indicated at 230. This crane comprises a beam 232 supported at its ends by means of rollers 234 upon tracks 235 which in turn are supported upon the sides of the building by brackets 231. A hoist or lift device 238 is supported on the upper surface of the beam 232 by rollers 240 and the operation of the crane is controlled from an operatorsvcage 242. A cable 250 extends downwardly from the lifting device When the platform 84 carrying the wet coated.v

article |5 emerges from the spray booth I8 onto the rollers 200, the crane is operated to impose an oven over the article. the platform by a suitable locking device such as that described in connection with the construction illustrated in Figs. 5, 6, and 7. The oven, platform, and article of manufacture may then be picked up by the crane and moved to a location where drying or siccative action may be carried on. The drying hood used is similar to that shown in Figs. 6 and 7 except that electrical harp |13 and bracket |80 are replaced by electrical outlets 255 in Fig. 8 in the platform, and carriers |10, rollers |12, track |08 and ceiling brackets |08 in Figs. 6 and 7 are replaced by floor rests 260. The drying oven is also provided in the top thereof with a ring bolt 265 with which the hook 252 may be engaged to lift the oven.

On the floor of the portion of the building containing the crane 230, I have located a plurality of positions arranged to receive the ovens |40', platforms 94', and the articles I5 as units and equipped with electrical outlets 210 to cooperate with the outlets 255. It is to these positions that crane 85 transfers the oven units from rollers 200, so that the siccative action may occur, while the oven units are upon oor rests 280. It will be noted that one important distinction between the form of the invention illustrated in Figs. 1a, 1b, 2, and 3 and Figs. 5, 6, and '1 and that illustrated The oven is latched to in Figs. 8 and 9 is that in the first two forms the drying or siccative action takes place while the ovens are in motion while in the last form the drying or siccative action takes place while the ovens are stationary. l

In Fig. 10 I have illustrated still another modification of oven |40 Figs. 6 and 7 or oven 20 Figs. 2 and 3. This oven is exactly similar in design to either oven 20 or oven |40, except that either one end 300 or one side is hinged by a single hinge 302 at its uppermost edge or by a plurality of hinges disposed at different vertical levels, so as to permit of the removal of article i5 without the necessity of raising the hood from the'level at which the siccative action occurs. This type of oven is of particular advantage in small installations such as repaint shops where it is not desirable to install extensive oven handling equipment such as is illustrated in Figs. la and 1b, 5, and 8, and in which it is desired, at the same time to simulate factory conditions in the drying or siccative action.

While I have illustrated and described certain specific mechanical embodiments of the idea of my invention it is to be understood that the invention is not limited thereto' but that such changes in the size, shape, and arrangement of parts may be resorted to as come within the scope of the subjoined claims.

Having now described my invention so that others skilled in the art to which it appertains may fully understand the same, what I desire to secure by Letters Patent is as follows:

l. In combination with a production line adapted to carry a train of wet coated articles through a siccative process a plurality of portable drying ovens comprising, open bottom hoods adapted to be applied to said articles individually without interrupting the progress of said train, means for applying said ovens to said articles at the beginning of said siccative process, means for removingr said ovens from said articles at the end of said siccative process, means for returning said ovens from the end to the beginning of the siccative process portion of said production line, and means for preheating the air contained in each of said ovens immediately before said oven is applied to said article.

2. In combination with a production line adapted to carry a train of Wet coated articles through a siccative process, a plurality of portable drying ovens comprising, open bottom hoods adapted to be applied to said articles individually Without interrupting the progress of said train, means for applying said ovens to said articles at the beginning of said siccative process, means for removing said ovens from said articles at the end of said siccative process, means for returning said ovens from the end to the beginning of the siccative process portion of said production line, and means for conserving the heated air or gases contained in each of the said ovens after the siccative process has been completed.

3. Apparatus for performing siccative action on articles of manufacture comprising, a plurality of separate article supports movable along a predetermined path, a plurality of portable drying inclosures cooperating individually with said supports to provide separate compartments for said articles during said siccative action, individual air heating and circulating means incorporated in each inclosure for carrying on said siccative action, means for transporting said ovens and article supports, and means for supplying energy to said individual air heating and circulating means along the path over which said ovens and article supports are transported.

4. 'I'he method of performing siccative action on wet coated articles of manufacture which comprises, moving said articles in series along a predetermined path, enclosing each of said articles in succession, applying heat to each of said articles individually, moving said series while the articles are so enclosed and heated, and finally, uncovering each of said articles in succession.

5. The method of performing siccative action on wet coated articles of manufacture which comprises, moving said articles in sequence along a predetermined path, applying separate ovens to said articles consecutively as said articles progress along said path, applying heat individually to the interiors of said ovens as the ovens and included articles progress along said predetermined path and exposing said articles at the completion of said siccative action.

6. The method of performing siccative action on wet coated articles of manufacture which comprises, moving said articles in series along a predetermined path, applying a separate oven to each article in succession Without interrupting the progress of said series, applying heat to each oven While said oven and the included article are being moved as a unit along said predetermined path, and removing said ovens from said articles in succession as the siccative action on the respective articles is completed.

7. The method of performing siccative action on wet coated articles of manufacture which comprises, moving said articles in series along a predetermined path, enclosing said articles consecutively in separate ovens, moving each article and enclosing oven as a unit along said predemined path, applying heat to each oven individually while it is being moved along said path, controlling the heat applied to each ovento carry on said siccative action in desired stages, and

removing said ovens from said articles at the completion of the siccative action on the enclosed article. i

8. The method of performing siccative action on wet coated articles of manufacture which comprises, moving said articles in series to a predetermined point, enclosing each article separately in a portable oven, moving each oven and included article as a unit away from said predetermined point, applying heat interiorly only of each enclosing oven to carry on said siccative action, returning said ovens and included articles to a predetermined point, and finally removing each article from the enclosing oven at said lastnamed predetermined point.

ROBERT R. LUNDY.