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Publication numberUS1638811 A
Publication typeGrant
Publication dateAug 9, 1927
Filing dateAug 5, 1926
Priority dateAug 5, 1926
Publication numberUS 1638811 A, US 1638811A, US-A-1638811, US1638811 A, US1638811A
InventorsMaehler Arthur, Siegele Karl
Original AssigneeMaehler
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of and apparatus for drying and enameling
US 1638811 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Aug. 9, 1927.

, A. MAEHLER ET AL METI-I OD OF AND APPARATUS FOR DRYING AND ENAMELING IIII //v v/v TORS. #Z VEHLE/7&/(A RL 157565.15,

M ATTORNEY.

I l l I I l I I I l I l I I I I l I l l I I l l I II Aug. 9 1927.

A. MAEHLER ET AL METHOD or AND APPARATUS FOR DRYING AND'ENAMELING Filed Au 5, 1926 4 Sheets-Sheet 2 5 MA TTORNEY.

' Aug. 9,1927. 1,638,811

A. MAEHLER ET AL METHOD OF AND APPARATUS FOR DRYING AND nmusmue Filed Au 5, 1926 4 Sheets-Sheet 3 A TTORNEY.

1,638,811 1927' A. MAEHLER ET AL mmron OF AND APPARATUS FOR DRYING AND ENAMELING Filed Auz. 5, 1926 4 Sheets-Sheet '4 A TTORNE Y.

the operation of the same,

Patented Aug. 9, 1927.

UNITED STATES PATENT OFFICE.

ARTHUR MAEHLER AND KARL SIEGELE, OF CHICAGO, ILLINOIS; SAID SIEGELE ASSIGNOR T SAID MAEHLEB.

METHOD OF AND APPARATUS FOR DRYING AND ENAMELING.

Application filed August 5, 1926. Serial No. 127,276.

This invention relates to that type of drying or enameling methods and apparatus 1n which the volatile constituents or solvents of a non-vitreous enamel coating are removed 5 by the combined action of heat and a normal and continued draft or circulation of air through the oven chamber, and discharged at a point outside such oven chamber. In such method and during the initial period in for instance the first twenty minutes, the main portion of the volatile constituents of the enameling coating are driven off as vapor into the oven chamber.

notsufiicient to properly carry off orreduce the proportion of such volatile and explosive vapor in the aeriform contents of the oven chamber, accidental and destructive explosions within the oven chamber are of frequent occurrence with material damage to the oven structure and adjoining portions of the building. With a view to remove such danger and liability to explosions within the oven chamber, the present improvements have for their main objects:

To provide means and a method of control. whereby a supply of heated air is forced through the oven chamber for a predetermined period of time and during the initial operation of the oven in order to attain a safe and effective dilution and removal of the excessive amount of explosive gaseous vapor given off by the enamel coating in the initial portion of the enameling or drying operation.

Another object of the improvement is to provide an automatic operative inter-connection of the motor of the pressure. blower by which the surplus supply of air, above referred to, is forced through the oven chamher, with the oven door or doors, so that the motor. will be rendered operative only when both the entry and exit doors are in their closed condition, when such operative condition of the motor is attained with the closing of the last one of said doors.

Still anther object of the improvement, is to provide a time controlled switch mecha- In that the normal draft or cir- I 15 culation of air through the oven chamber is nism, interconnected with the motor and the motor controlled door means, in order to automatically render said motor inoperative 1n a predetermined period of time after the normal starting of said motor in the initial portion of the present drying or enameling operation, all as will hereinafter more fully appear.

In the accompanying drawings:

Fig. 1, is a plan view of a drying and enameling oven having the present improvement applied and showing the electrically actuated and controlled type of the invention.

Fig. 2, is a longitudinal section on line 22 ,Fig. 1.

Fig. 3, is a transverse section on line 33, Fig. 2.

Fig. 4, is a detail sectional plan of the door switches, the time switch and its operating mechanism in their associated relations.

Figs. 5 and 6, are detail sectional plan views, showing other relative positions of the time and the door switch mechanisms.

Like reference numerals indicate like parts in the several views.

The means shown in the drawings to illustrate the present invention is the ordinary rectangular and indirectly heated type of oven, preferably of that form having a middle wall or partition 1 extending the length of the oven structure and intermediate of 8 the side walls 2 and 3 thereof, to divide the interior of the structure into a pair of oven chambers provided with entry and exit doorways in the front and rear walls of the oven structure, and with said doorways closed by 8 doors 4 and 5, as shown.

The indirect heating means for each oven chamber consists of the usual pair of opposed heating units located along the sides of the oven chamber, and with each of said units comprising a lower horizontal trunk 6, the chamber of which contains the heating means, either electrical or the ordinary gas burner 7 shown in Fig. 4, and a plurality of vertical mains or headers 8, extending up 05 from the trunk 6 and connected together by tubular members 9, with the parts coacting to perform the desired indirect heating function of an oven chamber. In the con struction shown, the central one of the headers 8 extends up through the oven roof and may have communication with the usual outlet or uptake stack of the oven.

In the ventilating means shown, the supply of outer air enters intake trunks 10 arranged horizontally in the over chambers, between the respective side and middle walls, 1, 2 and 3, and adjacent heating units, and at about the mid-height of the oven chambers, as shown in Figs. 2 and 3. At the midlength of the. oven, each of said intake trun ks 1U communicate with a vertical conduit 11 which in turn communicates with an outlet header 12 arranged longitudinally in the upper portion of an oven chamber, and having an opening or slot along its length for the passage of air in the upper portion of the oven chamber.

The associated means for eflecting an efiicient ventilating circulation of the air through the oven chambers involves an exhaust'fan or air mover 13, usually located on the roof of the oven structure, with its suction or intake trunk having dual connections as follows: With the upper portion of each chamber by a conduit 14 extending to a central longitudinally arranged vent duct 15 in said top portion of the oven chamber, and with the lower portion of each oven chamber through a central opening 16 in the floor thereof, and through conduits 17, extending to and communicating with the suction or intake trunk of the exhaust fan 13 aforesaid.

The means above described for heating and ventilating the oven chambers formsno material part of the present invention other than showing a practical and eflicient ventilating and indirect heating means for use in connection with the present invention.

A novel andmaterial portion of the present invention consists in the use of a rotary pressure blower 18, which in the construction shown in the drawings has communication in common with the two oven chambers of the structure by means of a plurality of conduits arranged as follows A central conduit 19 extending downwardly from the pressure outlet trunk of the blower 18, preferably at the outside of the oven structure, and discharging into the hereinafter described pair of conduits by which air from the blower 18 is heated and discharged into the upper portions of the oven chambers adjacent to the partition wall 3, separating said oven chambers. And a pair of side conduits 20, also extending downwardly from the pressure outlet trunk of the blower 18, preferably at the outside of the oven structure, and discharging into the hereinafter described conduits by which air from said blower is heated and dis charged into the respective upper portions of the oven chambers adjacent to the sides of the same.

The plurality of conduits within the oven structure, above referred to, are a counterpart construction, and each of said conduits preferably comprises a detail construction as follows:

A horizontal. trunk 21 arranged in a lower corner of an oven chamber and having communication at one end with the outlet trunk of the pressure blower 18 through. one or the other of the intermediate conduits 19, 20, aforesaid. Near to its other end the trunk 21 is divided by a horizontal partition 22 extending to near the midlen'gth of the trunk, and forming a return passage which has at such point communication with a verticalpassage 23, that opens into the before described vertical conduit 11 and longitudinally slitted head 12 of the exhaust ventilating means of theoven,

Each trunk 21 and conduit 23 above described are located in close proximity to a heating unit of the oven chamber, preferably between such unit and an adjacent side wall of the oven structure, and as so arranged will receive heat from the heating unit to properly temper the air passing through said conduit and header before the discharge of the air into the oven chamber. In that the central conduit 19 and the pair of horizontal trunks associated therewith, supply air to both oven chambers at points at opposite sides of the partition 3, of the oven structure, the said conduit 19 and trunk 21 will be made of a greater size of capacity than the side conduits 20 and their trunks, which have the opposed relation in an oven chamber as shown in Fig. 3.

Another and material part of the invention involves means for the automatic control of the operating motor 25 of the rotary pressure blower 18 aforesaid, so that motive power will only be supplied to said motor when, in the type of oven shown in the drawings, the entry and exit doors 4 and 5 are in a closed condition, and in like manner upon the closing of a single entry and exit door of another ordinary form of the present type of ovens. With the oven chambers filled with the articles to be dried or enameled, the heating means started, and the aforesaid oven doors or door closed, motive power will be automatically turned on the motor 25, to bring the pressure blower into action and obtain the added and forced ventilation of the present invention in the initial drying or enameling operation of the oven. Another material part of the invention involves the inclusion of an automatic time switch in the operating electric line or circuit 25 of the motor 25 of the pressure blower 18 aforesaid, and so that the supply of electro-motive shut off by the action of the automatic time switch when a predetermined period of time has elapsed after a starting of the oven operation.

The preferred construction and arrangement of parts and means for attaining the automatic control of the motor 25 above described consists as follows:

-An electric starter mechansim of any usual and suitable construction, usually of the three phase relay type, has connection with any usual source of electro-motive force and is adapted to regulate and'control the delivery of electro-motive force to an operating electrical circuit or line 27 in which is arranged the electric motor 25 of the rotary pressure blower 18 aforesaid. In such construction the electric line 27 is provided with automatic controlling means as follows:

A switch or circuit closer 28, usually of the ordinary push closing type, and individual to each oven door 4, 5, is included in the electric line or circuit 27 with the movable member of the switch 28 arranged for operative engagement by an oven door, to be moved to a closed condition as said'door is moved to a like closed condition. The construction and arrangement is such that the 7 of the automatic time switch mechanism 29 heretofore referred to and which is operated by any usual timing mechanism, preferably however by a train of speed reducing gearing arranged intermediate of the power shaft of the electric motor 25 of the pressure blower 18, and a shaft of said speed reducing gearing carrying the operating cam 30 of the switch mechanism 29. In the construction illustrated in Figs. 1 and 4, the operating cam 30, of a disk form is arranged to make a complete revolution in a period of on or about twenty minutes, and is provided with a cam projection 31 having operative engagement with a. sliding bar 32 so as to move the same positively in one direction, against the stress of a spring 33, tending to move said bar in the other direction.

The sliding bar32 has rigid operative connection with the movable member of the tion in connection with the opening of the time switch 29 by the cam projection 31,

involves means for holding said switch in its the path at the time switch bar 32, with theends of said bars 34 abutting at a point mid way the width of the bar 32. The respective ends of said door switch bars 34 are in the form of sliding spring shoes 35 attached to the bars 34 in a manner permitting limited independent movement between a shoe and a bar in a practical operation of the parts as follows:

With the oven door switches 28 in an open condition, the respective spring shoes are in abutting contact and adapted to support and hold the time switch bar 32 in the open condition of the time switch 29, and to which position the bar 32 had been moved by the cam projection 31 of the cam disk 30 aforesaid. The construction of'parts, permitting the withdrawal of the end of the time switch bar 32 from between the shoes 35 and a subsequent movement of said shoes beneath the end of the bar 32, to hold the tame in the position above described and maintain the time switch 29 in an open condition, and from the relation of parts shown in Fig. 5, to that shown in Fig. 4.

With the door switches 28 moving to an open condition in an opening of-the oven doors. the spring shoes 35 associated with said do or switches are withdrawn from beneath the end of the time switch bar 32 to permit the same to move and effect a closure of the time switch 29, but in that said time switch is in series with the open door switches, no electric current will pass to the motor 25 of the pressure blower "18 through the-supply circuit 25 aforesaid. ,With the -above described condition prevailing, the H emptying and refillingof the chamber of the oven is performed, and the oven doors closed. With such closure of the oven doors, the door switches 28 associated'with said doors also move to 'closedcondition to complete the motive power circuit 25 and cause the pressureblower motor 25 to operate. a

With the continued operation of said motor 25. the associated timing mechanism operates in unison therewith, and at the predetermined period of time brings the cam projection 31 into operative engagement with the time switch bar 32 to attain an opening of the time switch 29 and a stoppage of the operation of the motor and associated pressure blower 18. With such movement of the time switch bar 32'its end is withdrawn from between the spring shoes aforesaid, and said shoes will move under the influence of their springs beneath the end of the bar 32, to hold the same in such position, for succeeding series of the operations first described.

In the present improvement while the oven doors areopen, their switches 28 are in an open condition while the time switch 29 is in a closed condition, and the pressure blower 18 remains inactive during the break in the motor circuit 25 supplying its motor 25, With the oven doors moved to a closed condition at the beginning of the operation of the oven, the door switches 28 also move to a closed conditionto close the supply circuit 25 of the motor 25 and cause the same to operate the pressure blower 18, to supply thebefore described added supply of air to the oven chamber to properly ventilate the same in the initial portion of the operation of the oven. Such supply continues until the ameling operation, as the oven doors are opened for an emptying and refilling of the oven chamber, the door switches 28 also move to an open condition and in doing so withdraw the spring shoes 35 from beneath the time switch bar 32 to permit a movement of the sameto cause the closure of the time switch 29, but in that said door switches are in an open condition, the supply circuit 25 to the motor 25 will-not be completed until said door switches are again closed, in the next succeeding operation of the oven,

which started with the closing of the ovendoors and associated door switches 28.

Having thus fully described our invention what we claim and desire to secure by Let ters Patent is 1. The herein described method of operat ing drying and enameling ovens of the exhaust ventilation type, the same comprising the forcing of a supplemental supply of air through the oven chamber during the initial trolling the period of such supply by a timing means, and controlling said timing means in turn by the closed and the open' condition of the oven doors.

2. In a safety operating system for dry portion of the oven operation. A

3. In a safety operating system for dr ing or enameling ovens of the exhaust ventilation type, the combination of an oven structure, a pressure blower adapted to force a supplementary supply of air through the oven chamber, and a timing means controlling the operation of said blower and confine the operation of the blower to the initial portion-of the oven operation, and controlling connections between the doors of the oven and said timing means. 7

4:. In a safety operating system for drying and enameling ovens of the exhaust ventilation type, the combination of an oven structure, a pressure blower adapted toforce a supplementary supply of air through the oven chamber, an electric motor operatively :onnected to said blower, and an electric time switch mechanism controlling the operation'of said motor.

5. In a safety operating system for drying and enameling ovens of the exhaust ventilation type, the combination of an oven structure, a pressure blower adapted to force a supplementary supply of air through the oven chamber, an electric motor operatively connected to said blower, an electric time switch mechanism controlling the operation of said motor, and an electric switch individual-to and operatively connected to an oven door and arranged in series with said time switch mechanism in the motor supply circuit.

6. In a safety operating system for drying and enameling ovens of the exhaust ventilation type, the combination of an oven structure, a pressure blower adapted to force a supplementary supply of air through the oven chamber, an electric motor operatively connected to ,said blower, an electric time switch mechanism controlling the operation of said motor'and switches "indi-' vidual to the respective oven doors and ar-' ranged in series with said time switch mechanism in the motor'suppl'y circuit.

7. In a safety operating system for drying and enameling ovens of the exhaust ventilation type,.the combination of an oven structure, a pressure blower adapted to force a supplementary supply of air through the oven chamber, a electric motor operatively portion of the operation of the oven, con-'- oven 'door and arranged in series with the time switch mechanism of the motor supply circuit, the time switch mechanism, including a rotary cam having operative engagement with a bar of the movable contact member of the time switch to move the same to an open position, the movable contact member of the door switch having a bar moving in a path at right angles to the path of the bar of the movable contact member of the time switch and having a spring shoe at its free end adapted to engage an end of said time switch bar and hold the timing switch in an open condition.

8. In a safety operating system for drying and enameling ovens of the exhaust ventilation type, the combination of an oven structure, a pressure blower adapted to force a supplementary supply of air through the oven chamber, an electric motor operatively connected to said blower, an electric time switch mechanism controlling the operation of said motor, and an electric switch individual to and operatively connected to an oven door and arranged in series with the time switch mechanism of the motor supply circuit, the time switch mechanism including a rotary cam having operative engagement with a bar of the movable contact member of the time switch to move the same to an open position, the movable contact member of the door switch having a bar moving in a path at right angles to the path of the bar of the movable contact member of the time switch, a spring actuated shoe slidingly mounted on the free end of the bar of the movable contact member of the door switch, and means for limiting the independent movement of 'said shoe.

9. In a safety operating system for drying and enameling ovens of the exhaust ventilation type, the combination of an oven structure, a pressure blower adapted to force a supplementary supply of air through the oven chamber, an electric motor operatively connected to said blower, an electric time switch mechanism controlling the operation of said motor, switches individual to the ,respective oven doors and arranged in series with the said time switch in the motor supply circuit, the time switch mechanism including a rotary cam having operative engagement with a bar of the movable contact member of the time switch to move the same to its open position, the movable contact members of the door switches having operative connections with bars sliding in a path at right angles to the aforesaid bar of the time switch, each door switch bar having a spring shoe at its free end adapted to engage an end of the bar of. the time switch and hold said time switch in an open condition. r

10. In a safety operating systemfor drying and enameling ovens, the combination of an oven structure, anexhaust fan having duct connection with the top and bottom of the chamber of the oven structure, a pres sure blower having duct connection with said chamber and adapted to force a supply of air into the same, and means for confining the operation of said blower to an initial portion of the period of the oven operation. I

11. In a safety operating system for drying and enameling ovens, the combination of an oven structure, an exhaust fan having duct connection with the top and bottom of the chamber of the oven structure, a pressure blower having duct connection with said chamber and adapted to force a supply of air into the same, and an automatic tim ing means for confining the operation of said blower to an initial portion of the peri 0d of the oven operation. I

12. In a safety operating system for dry ing and enameling ovens, the combination of an oven structure, an exhaust'fan having duct connection with the top and bottom of blower having duct connection with said chamber and adapted to force a supply of air into the same, an automatic timing means for confining the operation of said blower to an initial portion of the period of the oven operation, and means operatively conthe sides of the oven chamber adjacent, to

the heating units thereof and adapted to force a supply of air into said chamber, and

means for confining the'operation of said blower to an initial portion of the period of the oven operation.

14: In a safety operating system for drying and enameling ovens, the combination of an oven structure, an exhaust fan having duet connection with the top and bottom of the chamber of the oven structure, a pressure blower having connection by delivery ducts with the mid-height of the chamber of the oven structure, with said ducts arranged at the sides of the oven chamber adjacent to the heating units thereof and adapted to force a supply of air unto said chamber, and an automatic timing means for confining the operation of said blower to an initial portion of the. period of the oven operation.

15. In a safety operating system for drying and enameling ovens, the combination of an oven structure, an exhaust fan having duct connection with the; top and bottom of the chambenof the oven structure, a pressure the chamber of the oven structure, a pressure blower having connection by delivery duets with the mid-height of the chamber of the oven structure, With said dliCfiS arranged at the sides of the oven chamber adjacent to the heating units thereof and adapted to force a-supply of air into said chamber, an automatic timing means for confining the operation of said blower to an initial portion of the period of the oven operation, and means operatively connected to a door of 10 the oven structure for controlling the operation of said timing means.

Signed at Chicago, Illinois, July, 1926.

ARTHUR MAEIHJER. KARL SIEGELE.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2507775 *Aug 8, 1945May 16, 1950Carnegie Illinois Steel CorpApparatus for thawing materials
US5282145 *Aug 29, 1991Jan 25, 1994Ronald LipsonMethod of repair paint curing for production lines and apparatus
Classifications
U.S. Classification34/487, 34/565, 432/12, 432/57, 432/51, 34/87
International ClassificationB05D3/04, C23D9/00
Cooperative ClassificationB05D3/04, C23D9/00
European ClassificationB05D3/04, C23D9/00