US2800725A

US2800725A - Apparatus for treating webs

Info

Publication number: US2800725A
Application number: US420003A
Authority: US
Inventors: Floyd A Holes
Original assignee: Dobeckmun Co
Current assignee: Dobeckmun Co
Priority date: 1954-03-31
Filing date: 1954-03-31
Publication date: 1957-07-30
Anticipated expiration: 1974-07-30

Description

July 30, 1957 F. A. HOLES 2,800,725

APPARATUS FOR TREATING WEBS Filed March 31. 1954 5 Sheets-Sheet 1 FlG.l

INVENTOR. FLOYD A.

w HOLES EL" Fr e.

x Mart; ATTORNEYS July 30, 1957 HQLES 2,800,725

APPARATUS F OR TREATING WEBS Filed March 31. 1954 ts-Sheet 2 FIG. Iw

I iI INVENTOR.

FLOYD A.

y 1957 F. A. HOLES APPARATUS FOR TREATING WEBS 3 Sheets-Sheet 3 Filed March .31, 1954 INVENTOR. FLOYD A.l-IOLES ATTORNEYS 2,800,725 APPARATUS son TREATING WEBS Floyd A. Holes, Solon, Ohio, 'assignor, by mesne assignments, to The Dobeckmun Company, a corporation of Ohio Application March 31, 1954, Serial No. 420,003

1 Claim. (Cl. 34-452) The present invention relates to ovens for continuously heat-treating webs, coated webs or laminated webs composed of various materials such as foils, films, paper, fabric, and the like.

Heretofore, the devices employed for heat-treating or curing webs and laminated webs or for drying coated webs were subject to one or more serious disadvantages. Prior devices generally required festooning the web in a chamber containing heated gases. This type of device, however, not only utilizes the heat very inefficiently but also requires a very large chamber so as to give the rapidly moving web sufficient .time within the chamber to effect the desired treatment. Another type of device employed a heated surface over which the web passed in direct contact in order to improve heat transfer. However, whenever it became necessary to stop the movement of the web, as, for example, when thefeed rolls or take-up rolls needed adjustment or when the coating device,if such were used, needed adjustment, the heat from the heated surface would damage or destroy the stationary web.

It is the object and advantage of the present invention that very efficient heat transfer to the web is obtained,

and yet movement of the web through the oven may .be stopped without damage or destruction of the web. Other objects and advantages will be apparent from the following description of a specific embodiment of the invention and the drawings therefor, in which:

Figures 1 and 1a illustrate in side elevation, partly broken away, a specific embodiment of the invention, and

Figure 2 is a cross-section taken along line 2-2 of Figure 1a, the view shown in Figure 2 being drawn to a larger scale than that of Figures 1 and 1a.

The oven, in general, comprises a plurality of heated elements or plates over which the web is passed and means for lowering the heated elements as a unit out of contact with the web while maintaining the web substantially in its original position. Thus, the web and the heated elements can'be separated whenever desired to prevent damage to ordestruction of the web, preferably without altering the path of travel of the web between the feed roll and the take-up roll and also without necessarily cooling the heated elements. The path of travel of the web through the oven is generally arcuate at all times so as to ensure uniform contact of the web with all of the heated plates when the web is drawn thereover and so as to provide a substantially uniform distance therebetween when the plates and web are separated.

With reference to Figure 1, there is provided a feed roll 11 carrying the web 12. This web is passed over idler rollers 13 and 14, as shown, and is coated with a lacquer or other coating composition adjacent roll 15 by any conventional coating device shown generally at 16. A supply pipe 17 for the coating composition is provided as shown. The feed rolls are driven by a motor 18 and conventional chain drives, including any conventional speed regulator (not shown) such as a speed governor controlled by the tension of the web or the diameter of the roll of web 12 on the roll 11. The motor 18 may tactthemin this position. However, when 2,800,725 Patented July 30, 1957 also drive the take-11p rolls, as will be described hereinafter.

It will be understood that the device 16 for applying the coating composition may be replaced by or employed in addition to other devices, such as laminating devices by which two webs may be aflixed together, or by which a web or laminated web may be printed with any desired design or indicia. When a coating composition or printing ink is applied to a web, the heat treatment is usually employed for drying or setting the coating composition or for evaporating the solvent from the ink. On the other hand, when a laminating operation is carried out, the subsequent heat treatment may be employed for setting the adhesive between the webs or for bonding the laminae together. Also, the heat treatment may be employed for stretching the webs of certain materials while in a heated condition.

When the web 12 leaves the roller 15 it passes over a uficession of spaced plates .19, which are heated as will be described in greater detail hereinafter.

With reference to Figure 1a, the web leaves the oven and is passed between tension rollers 20 and 21 which draw the web and maintain it under tension as it passes through the oven. The web then passes over idler roller 22 to take-up roll 23. As mentioned above, the take-up roll 23 may be driven by the motor 18 (Figure 1) by means of drive shaft 24 and conventional chain drives. The speed of the take-up roll may be regulated by any conventional device (not shown), such as a speed governor controlled by the tension of the web .or the diameter of the roll of web 12 on the take-up roll 23.

As will be seen in Figures 1 and la, the web 12 passes through the oven over plates 19, which are supported by transverse V-shaped supports 26 secured at their ends to the frame 27. Heating elements 28, which will be described in greater detail hereinafter, for heating the plates 19 are disposed between the V-shaped supports 26 and are mounted under the plates 19 and on the frame 27.

Pneumatic or

hydraulic jacks

29 and 29, or other type of lifting devices, are disposed between the ends of the oven and support the frame 27 by transverse beams 29". Thus, the frame .and the parts supported thereby, i. e., the heating elements 28, the V-shaped supports 26 and the plates 19, can be raised .or lowered as desired by operating the lifting devices 29 and 29' in synchronism.

When the frame 27 is in its uppermost position, as shown-in Figures 1 and 1a, transverse members 30, which are attached to a stationary frame 31 (see Figure 2) are located between andjust below the plates 19 and within the V of the supports 26, so that the web does not con- V theframe 27 is lowered, thus lowering the plates 19, the members 30 support the'webin substantially the same position as when the web 12 is supported by the plates 19.

A longitudinal hood 32 may be disposed over the oven and may extend down each side thereof. Passages or ducts 33 lead from the top of the hood 32 to vent heating gases, as will be described hereinafter.

The heating elements 28, as shown in the drawings, comprise gas burners extending transversely of the oven and mounted on the frame 27. As shown in Figure 2, the burners 28 are connected to one or more manifolds 38 which, in turn, may be connected to one or more flexible connections 39 to a source of fuel. Although gas burners have been illustrated in the drawings, it will be clear to anyone skilled in the art that other types of heating elements, such as oil burners or even electrical units, can be used if desired. While two burners 28 are shown located below each plate 19, it will be understood that a greater or smaller number of burners can be used if desired.

At the ends of each of the plates 19, a baffle wall 25 extends downwardly between the legs of adjacent V-shaped supports 26, thus forming an enclosed heating chamber which is open at the bottom to receive the combustion gases from the burners. The gases escape from the sides of the heating chambers and rise around the side edges of the plates 19 to the hood 32 andare vented through ducts 33. v a

Stabilizing devices are located at various points along the length of the oven. Such devices are shown at 34 and 35 in Figures 1 and 1a. Corresponding devices, such as the one shown at 35 in Figure 2, are located on the opposite side of the oven. Also, as shown best in Figure 2, stabilizing ,device 36 is located centrally of the oven adjacent lifting device 29. A companion stabilizer 36' is located similarly adjacent 'device29', as seen in Figure 1. Since each of the stabilizers operates in a similar manner, the following description will relate to the stabilizer shown at 36 in Figure 2. A flexible linked gear chain 40 is attached at its ends to stationary, fixed points at 41 and 42 which do not move with the frame 27. Two spaced

idler sprocket wheels

43 and 44 are rotatably mounted on the movable frame 27, the chain 40 passing around the

wheels

43 and 44 as shown. When the frame 27 is raised or lowered, the

wheels

43 and 44 are correspondingly raised or lowered. Any tendency for the frame to tilt about its longitudinal axis in a clockwise direction is prevented by the stabilizer 36, since such tilting would tend to increase the length of the path of the chain 40 from point 42 over the

wheels

43 and 44 to the point 41. However, it will be seen that stabilizer 36, as viewed in Figure 2, will not prevent tilting of the frame in a counter-clockwise direction, since such movement of the axes of the

wheels

43 and 44 tends to shorten the path of the chain 40. For this reason, the companion stabilizer 36' shown in Figure 1 is arranged as a mirrorimage of the one shown in Figure 2, i. e., the lower fixed point of the chain is on the right side instead of the left, and the upper fixed point is on the left side instead of the right; the chain passes over the right-hand sprocket wheel and under the left-hand sprocket wheel. Thus, stabilizer 36' will prevent the frame from tilting in a counter-clockwise direction but will not prevent tilting in a clockwise direction. Thus, to improve the stabilizing action of the devices, they may be coupled so as to act together and prevent tilting in either direction. To obtain this result, one of the sprocket wheels, say wheel 43, may be coupled, as, for example, by the shaft 45 (see Figures 1 and 1a), to the left wheel of stabilizer 36', i. e., the wheel under which the sprocket chain passes. In like manner, the device 35 may be coupled to the device 35 (see Figure 2) by a shaft 46, shown broken away for simplicity, and the device 34 may be coupled to the corresponding device (not shown) on the opposite side of the oven.

In operation, a web 12 is passed from the feed roll 11, over rolls 13, 14 and 15, then over and in contact with the spaced plates 19, through the oven to rolls 20 and 21, idler roll 22 and take-up roll 23. The plates 19 are heated by the heating elements 28 to provide the desired heat treatment of the web. The combustion gases from the heating elements 28, if combustible fuel is employed, with or without any vapors from the web, pass into the hood 32 and are vented through ducts 33.

When it becomes necessary to stop the web in order to prevent damage or destruction thereof, jacks 29 and 29 are operated to lower the longitudinal frame 27 and thus lower the heated plates 19 and heating elements 28. The transverse members 30 are not lowered, and the web 12 will be supported thereby as soon as the plates 19 have moved below the members 30. Thus, the web and the heated plates are separated so as to prevent damage to the web. The heating elements 28 may be left on, if desired, particularly when the heat-treating of the Web is expected to be resumed in a short time.

When the frame 27 is lowered,

stabilizers

34, 35 and 36 and the stabilizers to which they are respectively connected, as explained above, operate to prevent tilting of the frame 27 about a transverse axis or about a longitudinal axis.

As soon as heat-treating of the web is to be resumed, the

jacks

29 and 29 raise the frame 27 until the plates 19 pass above the elements 30 and again support the Web along its length.

Although the present invention has been described with particular reference to the drawings, it will be understood that various modifications will occur to those skilled in the art, and it is intended that such modifications which come within the scope of the appended claims be covered thereby.

What is claimed is:

' Means for heat-treating a movable Web comprising an oven structure, said oven structure comprising a frame and a hood movable relative to each other, and perpendicular to the length of said oven structure, a plurality of heated plates supported by said frame in longitudinally spaced relationship and arranged on said frame to support, in normal operation, a web moved through said oven, means to heat said plates, a plurality of longitudinally spaced transverse members fixed relative to said hood and normally located between said plates along the path of travel of said web, and means to move said frame and hood relative to each other so that said transverse elements will support said web away from said plates.

References Cited in the file of this patent UNITED STATES PATENTS 1,229,101 Linfoot June 5, 1917 1,266,735 White May 21, 1918 1,360,323 Sass Nov. 30, 1920 1,432,302 Reed Get. 17, 1922 1,571,282 Leculier Feb. 2, 1926 1,710,442 Warshaw Apr. 23, 1929 1,924,100 Barker Aug. 29, 1933 2,646,968 Curtis July 28, 1953