BACKGROUND OF THE INVENTION The prior art granule application device is described in United States Patent No. 4,478,869, issued October 23, 1984. Related disclosures appear in United States patent Nos. 1,669,166, issued May 8, 1928; 2,111,565, issued March 22, 1938; 2,160,787, issued May 30, 1939; 2,211,204, issued August 13, 1940; 2,233,122, issued February 25, 1941; 2,356,570, issued August 22, 1944; 2,400,746, issued May 21, 1946; 2,661,303, issued December 1, 1953; 3,132,964, issued May 12, 1964; 3,184,324, issued May 18, 1965; and 4,352,837, issued October 5, 1982.

The prior art granule application devices generally include a blender applicator with a recycle applicator disposed immediately downstream of the applicator and a sheet for travelling under these applicators to receive the granules.

One of the basic problems with the prior art granule application device is that a substantial volume of expensive granules from the blender applicator have to be recycled into a recycle applicator from the travelling sheet.

SUMMARY OF THE INVENTION According to the present invention, a granule application device is provided for applying granules to a travelling sheet which includes a blender applicator, a recycle applicator, a headlap appli¬ cator and a dispensing control disposed between the blender applicator and the recycle applicator. The headlap applicator is arranged with a dis¬ pensing control between the blender applicator and the

recycle applicator to minimize the recycle volume of - the expensive granules from the blender applicator and for increasing the recycled volume of the less expensive granules from the headlap appli-cator. This arrangement avoids the problem of re- cycling a substantial volume of expensive granules from the blender applicator into the recycle appli-cator from the travelling sheet.

The foregoing and other objects, features and advantages of the invention will be apparent from the following detailed description of the preferred embodiment of the invention.

DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic perspective view of a granule application device according to the invention; Figure 2 is an elevation view of the granule application device of Figure 1;

Figure 3 is a section view taken along the line 3-3 of Figure 2; Figure 4 is a section view taken along the line 4-4 of Figure 2; and

Figure 5 is a top view of the granule bin arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in Figures 1 and 2 of the drawing, a granule application device for use in making a shingle roofing product is generally indicated at 10. The device includes a backfall or recycle applicator 12, a headlap applicator 14, a variegated or blender applicator 16. A web or sheet 18 travels under the applicators 12, 14 and 16 for receiving granules from the applicators.

Figure 2 shows the sheet 18 supported by a talc

drum or roll 20, a slate drum or roll 22, and a seal drum or roll 2&. All the drums 20, 22 and 26 are mounted on a support structure 28, which rests on a concrete floor 30. Referring to Figures 2, 3 and 5, granules are fed from bins 33, 38, 50 and 60. Each bin is divided into sections or blender bins. The recycle applicator 12 is fed granules from bin 33 through drop tubes 31A, 31B, 32A and 32B located in backfall bins 33A through 33D. The recycle applicator 12 is also fed granules by drop tubes 34, 35, 36, 37 from scrap bins 38C and 38D. The headlap applicator 14 is fed by drop tubes 39, 40, 41, 42 from headlap bins 38A and 38B. The blender applicator 16 is fed by drop tubes 43, 44, 46, 48 from blender bins 50A through 50D. The blender applicator 16 is also fed by drop tubes 52, 54, 56, 58 from blender bins 60A through 60D.

As shown in Figure 2, the granule application device 10 also has a seal back wiper 62, which is disposed adjacent to a seal roll 26 which can be used for applying a back coating. The granule application device 10 also has a recycle slate conveyor 64, which is disposed near to the recycle applicator 12 and the scrap bins 38C and 38D. The conveyor 64 has an input recycle chute 63. The recycle applicator 12 also has an input recycle chute 65.

In Figure 3, recycle applicator 12 has compartments or chambers 66, 68, 70, 72, 74. The headlap applicator 14 has similar chambers 76, 78, 80. The blender applicator 16 also has similar chambers 82, 84, 86, 88, 90, 92, 94, 96. In Figure 2, the recycle applicator 12 has a machine driven roll and gate unit 98. The headlap applicator 14 has a manually operable roll and gate unit 100. The blender applicator 16 also has four machine driven roll and gate units 102, 104, 106,

108.

In Figure 2, roll and gate units 98, 100, 102, 104, 106, 108 have respective adjacent deflector plates 110, 112, 114, 116, 118 and 120 for deflecting the granules during their fall.

The manually operable roll and gate unit 100 is a variable speed unit, and it is independent of the speed of a machine drive. The gate is opened by manual control. The roll and gate unit 98 connects to a machine drive (not shown) by a varigator link unit 99. The roll and gate unit 100 has a manually operated D.C. control unit 101. The roll and gate units 102, 104, 106 and 108 are also mechanically linked to the machine (not shown) , so that a speed change of sheet 18 will cause a proportional speed change in the flow of granules from the blender applicator 16, and from the recycle applicator 12. In this way, a respective constant thickness of granules are applied by the blender applicator 16 and by the recycle applicator 12 on sheet 18, regardless of the speed of travel of sheet 18.

In Figure 4, the deflector plate 112 of the headlap applicator 14 is shown. The plate 112 has three flat guide portions 124, 125,.126, a bent portion 127, two protected backfall zones 128, 129, and directional guides 130, 131, 132, 133.

In Figure 2, the device 10 has a cutter unit 134, which is disposed downstream of drum 20. The device also has a coater assembly 136, which is disposed upstream of the roll 26. The cutter unit 134 cuts sheet 18 -into pieces to form shingles. A coater assembly 136 applies a conventional sticky material, such as asphalt, to the facing surface of sheet 18 prior to the application of the granules.

In operation, the blender applicator 16 applies blended prime butt granules to the surface of the sheet 18 only in the exposed drop areas of the butt. The headlap applicator 14 then applies virgin granules to the headlap area which had not been exposed to the blender applicator. The backfall applicator 12 then applies a general coverage of granules across the entire surface of the sheet using a combination of recycled granules and virgin make-up granules. The backfall box of the backfall applicator is zoned so that the combined recycle headlap granules and virgin headlap granules are applied only in the headlap zones on the sheet.

The headlap applicator applies a thickness of less expensive headlap granules only on the non-exposed headlap area of the surface of the sheet; so that the headlap area of the surface of the sheet will ultimately have a double thickness of granules. The thickness of granules is adjusted by manual operation of control unit 101. The granules applied to the non-exposed headlap area of the sheet by means of the deflector plate 112 are applied in controlled distinctive lines.

The recycle applicator 12 applies a uniform thickness of granules to the surface of the sheet. In one embodiment of the invention, the sheet width is about forty eight inches, which includes two outer six inch wide headlap strips and one center twelve inch wide headlap strip and two intermediate twelve inch wide weather exposed butt strips, so that sheet can be cut along three cutting lines to form four longitudinal shingle strips. The recycle applicator 12, which is about forty eight inches wide, has two outer six inch wide chambers 66, 74 with recycle or scrap granules for the two outer six inch wide headlap strips. The

recycle applicator 12 also has one center twelve inch wide chamber 70 with recycle or scrap granules for the one center 12 inch wide headlap strip. The recycle applicator 12 also has two intermediate twelve inch wide chambers 68, 72 with clean new backfall granules for the two intermediate twelve inch wide weather exposed butt strips.

The varigator link unit 99 is adjusted, to provide just slightly more new backfall granules to the exposed butt area than will be imbedded and accepted by the coated sheet 18.

A typical process of manufacture utilizing the granule application device 10 is as follows. A sticky, asphalt material is applied over the total facing area of sheet 18 by coater assembly 136. The blender applicator 16 dispenses blended granules over the butt area of sheet 18. The headlap applicator 14 then dispenses headlap granules over the headlap area of the sheet 18 at a rate of flow as set by an operator. The recycle applicator 12 dispenses recycled granules over the headlap granules and the butt (exposed) area on sheet 18. The blender applicator 16 and recycle applicator 12 are machine driven and dispense at a rate of flow in proportion to the rate of movement of sheet 18. Cutter unit 134 then cuts sheet 18 into elongate shingle strips by a peripheral blade, and into pieces by a transverse blade, at a rate in proportion to the speed of movement of sheet 18.

The advantages of the invention are indicated hereafter.

A. The total area available in the non-exposed headlap area is covered with less expensive headlap granules by the headlap applicator 14; and there is

substantially no contamination of headlap granules in the exposed butt. area.

B. Less expensive granules are applied twice to the non-exposed headlap area, in order to insure relative larger weight in the non-exposed headlap area.

C. By reducing the amount of granules applied to the exposed butt area, there is more enhancement of the blended granule drops in the exposed butt area and there is less contamination of headlap granule in the exposed butt area.

While the invention has been described in its preferred embodiment, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made within the purview of the appended claims without departing from the true scope and spirit of the invention in its broader aspects.