Technical Field

This invention relates to continuous production of foam material and more particularly to an apparatus which produces substantially flat top foam materials of differ- 5 ent widths- Background Art

Foam sheets have been made from a liquid polyure- thane foaming material spread on a continuously moving channel-shaped conveyor. The problem encountered with 0 this type of apparatus is that the side fences of the conveyor cause a downward drag on the rising foam, re¬ sulting in a convexly curved top on the sheet. For most uses of the foam, such as for furniture, the tops have to be flat to produce a desired seating surface. Most often

15 the convexly shaped tops were cut to a flat top and the removed material was scraped.

Side fences have been developed which not only move with the bottom conveyor but also move upwardly with re¬ spect to the bottom conveyor where the foam rises to lessen

20.. or eliminate any downward drag caused by the side fence. Such side fence mechanisms are disclosed in U.S. patent 3,325,82β issued to Boon on June 13, 1967, and U.S. patent 3,091,811 issued to Hackert on June 4, 1963.

These devices are limited to a variety of foaming

25 materials which can be used, since different foaming materials have different foaming rates. If the foaming rate is too fast, the drag is not eliminated and if the foaming rate is not fast enough, the side fences could cause upward drag, resulting in a concave top surface,

30 a feature as undesirable as the convex top.

The sloped portion of the conveyor has to have its slope adjustable. U.S. Patent 3,832,099 issued to Berg on August 27, 1974 discloses a vertically adjustable section of the bottom conveyor.

35 The apparatus using a sloped bottom conveyor and upwardly inclined side conveyor adequately produce flat

top foam blocks which can be cut to whatever desired length after the foaming is completed. However, if narrower foam blocks are desired, the foam blocks have to be sheared to form the narrower foam block. The cut- ting creates a waste of foam plus an extra process in making the final foam block. Disclosure of Invention

According to the invention, an apparatus for con¬ tinuously casting foam sheets has a bottom conveyor posi- ^• tioned below a means for supplying liquid foaming reagents thereto. Sidewalls are adjacent the conveyor to retain the foam as it rises on the conveyor. The side walls preferably have a surface moving in the direction of. the foam and at the same relative speed. Preferably the surface is a paper sheet supported by a longitudinally stationary supportive wall. Means for controlling the upper contour of the rising foam are alongside of the side fences at a first portion of the conveyor. Prefer¬ ably a means for controlling the upper contour of the foam includes the first portion of the conveyor angled down¬ wardly with respect to the sidewalls.

Means are connected to the side walls for adjustably moving the sidewalls for controlling the width of the space between the sidewalls such that the width of the foamable material on the conveyor is adjustable. Also means adjust the width of a portion of the conveying means. Preferably the adjusting means include the first portion of the con¬ veyor longitudinally divided into at least two platforms with sliding means connected to each platform for sliding one longitudinal platform with respect to another in a horizontal direction transverse to the length of the con¬ veyor. It is desirable that the side walls are adjacent the outer edges of the first portion of the conveyor. Means for covering the gaps between the platform is connected to at least one platform.

Further, according to the invention, the conveying surface of the conveyor is a flexible sheet which conveys

the foaming material as the material is molded. Means for fitting the flexible sheet between the spaced side walls are attached to the conveyor upstream from the side walls such that the outer edges of the sheet are adjacent the side walls.

Brief Description of Drawings

The invention will now be described with reference to the accompanying drawings in which:

Figure 1 is a side elevational view of a conveyor system illustrating a preferred embodiment of the inven¬ tion.

Figure 2 is a partially segmented enlarged side ^' elevational view of the embodiment illustrated in Figure 1. Figure 3 is a partially segmented enlarged side view of the embodiment shown in Figure 2 in a second position of the conveyor.

Figure 4 is an enlarged fragmentary and partially broken plan view of the embodiment shown in Figure 1. Figure 5 is a side cross-sectional view taken along lines 5-5 in Figure 4.

Figure 6 is a side cross-sectional view as shown in Figure 5, showing a second position of the side walls.

Figure 7 is a skeletal perspective view of the adjustable stands of the preferred embodiment of the invention.

Figure 8 is an enlarged elevational view of a paper cutter as shown in Figure 2 taken along lines 8-8 in Fig¬ ure 2. Best Mode for Carrying out Invention

Referring particularly to Figure 1, an apparatus generally indicated as 10 has a frame 12 supporting a mixing head 14. Various hoses 16, tanks, and pumps are connected to the mixing head in a conventional fashion for supply of foamable liquid. A conveyor 22, originating from a paper roll 24 passes over and is supported by a -F.τ.«. -oortion 26 called a pour plate, passing under mixing

head 14, and passes over and is supported by a second portion 28 and third portion 29 extending from the pour plate 26 to a foam saw apparatus 30. The pour plate 26 is disposed at an acute angle to the horizontal. At the 5 sides of the conveyor 22 are side fences 32. A paper roll 34 has its paper 35 unwind and abut the inner surface of the side fences 32 to a take up roll 36.

As more clearly shown in Figures 2 and 7, the mix¬ ing head 14 is attached to chain 38 which is trained

1.0 around sprockets 40 and driven by motor 42. The mixing head 14 is driven back and forth, traversing the width of the conveyor. The sprockets 40 are contained in a sprocket housing 44.

A worm gear 45 is operably mounted within the frame

15 12. The worm gear 45 is operated by handle 46 through gear reducer 48. The reducer 48 turns the worm gear shaft 50. The gear reducer is mounted on frame 12. The bottom of the worm gear shaft 50 is also rotatably mounted on the frame 12. A brass block 56 has stabilizer lugs 58 which

20' engage the frame 12. The threaded block 56 also engages the gear shaft 50 so when the shaft rotates, the threaded brass block is raised or lowered. The sprocket housing 44 is also connected to the brass block 56 and is correspond¬ ingly raised or lowered. At the bottom of the gear shaft

25 50 is a sprocket 54. A chain 63 is trained around the sprocket 54 and engages a sprocket 54a as seen in Figure 7 at the other side of the conveyor which also is attached to a worm gear shaft 50a of a worm gear 45a similar to the one described but lacking the gear reducer and handle.

30 The sprocket housing 44a at the other side of the conveyor is similarly connected to a brass block 5.6a which is similarly raised or lowered by the rotation of handle 46. Handle 46 can be also replaced by a motor which drives the gear reducer 48.

35 The mixing head frame 12 is mounted oh bases 52 which slidably ride on tracks 62. Each base 52, as shown in Figures 5 and 7, is connected by a transverse bar 64

which, in turn, is connected to a motor housing 70. The motor housing 70 is mounted on a stationary worm gear shaft 68. The motor rotates a threaded brass block 66 which engages the worm gear shaft 68. As the brass block threads up and down the shaft 68, the bases 52 slide within their tracks 62.

Referring back to Figure 2, the pour plate 26 is positioned below the mixing head 14. The pour plate 26 is divided into an upper section 74 and lower section 76, hinged together by hinge 78. At the lower edge 80 of the lower section 76, a transition plate 82 is connected to the lower section 76 by hinge 84.

Referring now to Figures 2 and 4, the pour plate 26 is supported by three pairs of stands: 86a and 86b, 90a and 90b, and 88a and 88b. One stand 86a, 88a and 90a of each pair, is positioned at the near edge of conveyor. The other stand 86b, 88b and 90b of each pair is positioned at the far edge of the conveyor. Stands 86a and 86b support the upper edge 92 of the upper section 74. The pair of ' stands 88a and 88b support the lower edge of the upper section 74 near hinge 78. The third pair of stands 90a and 90b supports the lower edge 80 of the lower section 7-6 near hinge 84.

Each of the stands 90a, 92a and 94a contains worm gears 96a, 98a, and 100a, respectively. The worm gears are the same general type as worm gear 45 connected to mixing head 14. The worm gears 96a, 98a and 100a each has a rotatable handle 102a, 104a and 106a, respectively. Each handle is respectively connected to gear reducer 108, 110 and 112 which are connected to a top end of worm gear shaft 114, 116 and 118, respectively. Each gear shaft is rotatably mounted onto a vertical gear housing 126, 128 and 130, respectively. Brass blocks 132, 134 and 136 having threaded holes threadably engage the worm gear shaft 114, 116 and 118, respectively. Brass block 132 is rigidly connected to bracket 156 which is connected to central track 138.

As shown in Fiαure 7, rotatably mounted to the brass

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blocks 134 and 136 are brackets 158 and 160 extending toward the central portion of the conveyor 22. The brackets 158 and 160 have vertical extensions 164 and 166 respectively mounted to slide tracks 140 and 142. Figure 5 shows another view of the bracket 158 and vertical extension 164.

At the bottom of worm gear shafts 114, 116 and 118 are sprockets 144, 146 and 148, respectively. Chain 150 is trained around sprockets 144 and 144a; chain 152 is trained around sprockets 146 and 146a; and chain 154 is trained ^' around sprockets 148 and 148a. Each sprocket is connected to a like worm gear shaft 114a, 116a and 118, respectively. Each worm gear shaft is rotatably mounted in housing 126a, 128a and 130a, respectively. Brass blocks 132a, 134a and 136a are threaded onto the respective shafts 114a, 116a and 118a. Brass blocks 134a and 136a are rigidly connected to brackets 158a and 160a. Vertical extensions 164a and 166a connect the re¬ spective brackets onto the slide tracks 140 and 142. Brass ' -block 132a is connected to track 138.

The rotation of the handles 102, 104 and 106 re¬ spectively rotate the worm gear shafts 114, 116 and 118, and the sprockets 144, 146 and 148. The chains 150, 152 and 154 move to correspondingly rotate the shafts. ^• As the worm gears are rotated, the threaded brass blocks 132, 132a, 134, 134a, 136 and 136a are raised and lowered on the shafts 114, 114a, 116, 116a, 118 and 118a. The brackets 156, 158 and 160 and 156a, 158a and 160a also are correspondingly raised and lowered which, in turn, raise or lower pour plate 72.

As shown in Figure 3, compared to Figure 2, the upper and lower sections 74 and 76 of the pour plate 26 can be adjusted to different heights and different in¬ clinations. Referring now to Figures 4, 5 and 7, the pour plate 26 is longitudinally divided into three platforms or panels 168, 178.and 188. The vertical extensions 164, 164a, 166 and 166a are attached to center tracks 140 and 142,

respectively. Brackets 156 and 156a are directly attached to center track 138. Each center track 138, 140 and 142 is mounted transversely to the length of the conveyor to a bottom surface of a central panel 168 of the pour ^' plate 72. The central panel 168 has an upper section 169 and lower section 170 corresponding to the upper and lower sections 74 and 76 of the pour plate 72.

Slidably mounted to the central tracks 138, 140 and 142 respectively are left tracks 172, 174 and 176. Left tracks 172 and 174 are mounted to a bottom surface of a left panel 178 of the conveyor pour plate. Again, the left panel 178 has an upper section 179 and a lower sec¬ tion 180 corresponding to the upper section 74 and lower section 76 of pour plate 26. Likewise, right tracks 182, 184 and 186 are at¬ tached to the right panel 188 of the pour plate 72. Again, the right panel is also hinged between an upper section 189 and a lower section 190 thereof.

Particularly referring to Figures 4 and 5, the central panel 168 is a hollow elongated channel with a bottom strip metal interfitted on a top strip 192.

Likewise, the left and right portions 178 and 188 respectively have a bottom strip 194 and 196 interfitted with a top strip 198 and 200. The left and right panels 178 and 188 are slidable toward and away from the central axis of a central panel 168. Attached to the top strip 192 is a cover piece 202 which extends outwardly from the outer edges of the top strip 192 and bridges the gaps 204 between the central panel 168 and left and right panels 178 and 188, respec¬ tively.

As shown in Figures 4, 5 and 6 an air hose 206 is connected to the bottom strip 191 of the central panel 168. A plurality of apertures 208 extend through the top strip 192 of panel 168 and also through the cover piece 202 to be in fluid communication with the air hose 206. A blower 211 is op ^' erably connected to the air hose 206 to blow air through the air hose through the upper and lower section

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169 and 170 of..central panel 168.

Attached to the bottom of the side panels 178 and 188 are flanges 210. The bottom edge of each flange is welded to a threaded shaft 212. The threaded shaft ex- tends through a slot 214 within brackets 216. Nuts 217 threadably engage the shaft 212 at both sides of brackets 216. The brackets 216 extend upwardly and are affixed to the side fence 32.

Referring to Figures 2 and 7, vertical supports 220 and 221 extend upwardly from each side fence 32. The vertical supports are attached to the side fence 32. The base 223 and 225 of the vertical supports are slidably mounted on track 227. At the top of the vertical supports 220 and 221 are housings 222 and 229, each of which rigidly secures brass nuts 224 and 224a, respectively. The brass nuts 224 and 224a engage a threaded shaft 227 with the left side thereof threaded in one direction and the right side threaded in the opposite direction. The shaft 226 is operably connected to a motor 228 such that ' when the shaft 226 rotates, the left brass nut 224a and right brass nut 224 will be simultaneously moved axially along the shaft to slide the supports along stationary track 227 and move the side fences 32 toward the central longitudinal axis of the conveyor, or away from the said axis. As the side fences 32 move to and from the central axis, the left and right panels 178 and 188 correspondingly move under the cover piece 202, either toward or away from the central longitudinal axis of the conveyor.

Referring particularly to Figures 5 and 6, the conveyor is shown in two distinct positions ^" with the side fences 32 and side panels 178 and 188 located toward the central axis of the conveyor 22 in Figure 6.

As shown in Figures 1 and 2, a paper roll 24 unwinds paper 232 to cover the panels 168, 178 and 188 and contin- ues through the second portion 28 of the conveyor 22. The paper 232 has a width adapted to fit the conveyor at the widest position as shown in Figure 5.

Mounted in proximity of the top edge of the first

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port on 6 o the conveyor are paper ro ers 0 to o the outer edges 234 of the paper sheet 232 from the paper roll 24. The outer edges 234 are folded vertically by rollers 230. Downstream from the paper rollers 230 and fixedly connected to the side fences by supports 236 is a paper cutter 238. The paper cutter is located above each outer edge of the side panels 178 and 188 as shown more clearly in Figure 8. The paper cutter has two vertical plates 240 and 242 placed parallel and slightly to the inside of the side fences 32. A relatively thin space 243 lies between the two opposing plates 240 and 242. The opposing plates have at their top portions supports 244 which extend through the side panels and are fixedly connected thereto. A horizontal slot 245 extends through both plates 240 and 242. A knife blade 246 with its plane parallel to the plate of the upper section 74 of the pour plate 72 has a cutting edge toward the paper roll 24. The knife blade 246 cuts excess height from the vertical outer edges 234 of the paper 232 as the paper 232 travels along the con¬ veyor 22 and retains a vertical lip 235.

In operation, a liquid foamable material 11, such as polyurethane, passes out of the mixing head 14 onto the moving paper 232. The moving paper has its outer edges vertically folded by the paper rollers 230. Before the foam 11 rises any significant amount, the vertical edges of paper 232 are cut ^* by the paper cutter 238. The paper and foamable material move downstream to where the side paper rolls 34 unwind paper 35 to the inner surface of the side fences 32. Both of the side fence papers 35 move at the same speed as the paper 232, As the paper 232 moves downwardly down the slope pour plate 26, the foam 11 rises above the lip 235 and abuts the side fence paper 35, The foam rises at approximately the same rate as the paper 232 declines down the lower section 76 of the inclined pour plate 26. It should be apparent from the foregoing. that most of the foaming takes place on the lower section 76 of the pour plate 26 although a small

amount of foaming takes place at the upper section 74 thereof and the final stages of foaming take place on the horizontal conveyor portion 28 as illustrated in Figure 2. The upper section 74 is positioned at a slight angle or declination to the horizontal to permit the foaming ' material, while it is relatively fluid, to reach the point at which substantial foaming begins and it becomes viscous enough to accommodate the steeper declination angle of the lower section 76 without significant flowing down the pour plate. When the foam has substantially reached its final height, the paper 232 passes over the transition plate 82 onto the horizontal second portion 28 of the conveyor 22. The foam is still retained by the side fences until it reaches the end of the second portion 28. The foam is then set to freestanding form as it moves down to the third portion 29 of the conveyor 22 and then to the saw 30 where the foam is cut into blocks of predetermined lengths.

As shown in Figure 5, when a narrower foam block is ' desired, the motor 228 rotates the worm gear shaft 226 mounted above the side fences 32 and the brass nuts 224 and 224a are moved inwardly toward the center of the shaft. The side fences are then moved closer together and simul- - taneously the side panels 178 and 188 slide inwardly on the tracks 172, 174, and 176 and 182, 184, and 186 along the center tracks 138, 140, and 142. The mixing head pours liquid foamable material onto the paper 232 as the paper 232 moves downstream along the conveyor 22. The outer edges 234 of the paper 232 is folded upwardly and the cutter 238 cuts the excess height off the outer edges to retain a lip 235 of approximately one inch. The foam 11 foams in the same manner as previously discussed and is retained by the now closer side fences 32. The excess paper 237 cut by the paper cutter, 238 is moved upwardly along paper 35 as the foam rises therealong.

Different foams, having different foaming rates, must be accommodated to achieve the flat top which is desired in foam blocks. Adjustments can be made to the

foaming head by moving it longitudinally with respect to the conveyor by operation of motor 70 which moves the mix¬ ing head frame 12. The height of the mixing head can also be adjusted by the operation of the handle 46 connected to worm gear 45.

In addition, the inclination of the upper section 74 and lower section 76 of the pour plate 72 can be ad¬ justed so that the relative rise of the side paper 35 can be increased or decreased as shown in Figures 2 and 3. The operation of worm gears 96, 98, and 100 adjust the height and inclination of the upper section 74 and lower section 76 of the pour plates 72 with respect to the side fence 32. Adjustments to the inclination of the upper section 74 and lower section 76 of the pour plate 72 may be desired even when the same foam is used if the side fences 32 are differently spaced apart.

The vertical lip 235 of the paper 232 is slightly spaced from the side fences so that friction between the two papers 35 and 232 is minimized. The side fences 32 can be adjustably spaced from the side panels and vertical lip 235. As shown in Figures 5 and 6, the nuts 218 can be threaded along the shaft 212 to horizontally move the brackets 216 and consequently the side fences 32 relative to the side panels 78 and 88 to bring the side fence closer to the vertical lip 235 or slightly farther away from the vertical lip 235.

As the paper 232 moves downstream, it floats on a thin film of gas supplied through the plurality of aper¬ tures 208 through the cover plate and central panel. The thin film reduces drag on the conveyor until the paper 232 flows into the second portion 28 of the conveyor.

In this fashion, a continuous foam molding apparatus can be adjustable to make flat foam blocks of different widths and heights. The side fences are free to move in and out without interference from the sloped pour plate therebetween. The sloped pour plate is correspondingly adjustable to retain its outer edges adjacent the side fences in a plurality of positions while retaining a

substantially flat surface width wise suitable for receiv¬ ing foaming reagents thereon.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, drawings, and the apended claims without departing from the spirit of the invention.