Abstract:
An automatic brickwork stencil making machine formed in two production lines on a table top base. A roll of adhesive coated tape in each line is processed to pick up tabs positioned perpendicular to the moving tape, a tamper secures the tab on the tape, and a take-up spool driven by a motor rolls up the completed product for use in making brickwork layouts on vertical or horizontal planar surfaces.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to stencils. More specifically, the invention is an automatic stencilling machine which forms two rolls of a brick wall simulating stencil simultaneously on a table-top surface. 
     2. Description of the Related Art 
     The related art of interest describes various stencil making machines, but none discloses the present invention. There is a need for an economical and portable stencil producing machine with a compact work surface, such as a table top, with the stencils brought on-site for installing brick facades on a multitude of construction materials, such as a driveway, cement board, block foam, plywood, drywall, plasterboard, glass cement slabs, around and in pools, metal, and brick stone. The related art will be discussed in the order of perceived relevance to the present invention. 
     U.S. Pat. No. 1,783,810, issued on Dec. 2, 1930 to John H. Petersen, describes a stencil printing machine of the type for printing on or decorating textile fabrics. The machine synchronizes the stencil material and the stencil cylinder to move at the same rate of speed to ensure accuracy in the printed or decorative designs or patterns. The machine is distinguishable for its stencil cylinder and its associated drive mechanism. 
     U.S. Pat. No. 2,452,959, issued on Nov. 2, 1948 to Melvin H. Sidebotham, describes a machine for thermoplasticallyl treating materials of the sheet material type in a reel-to-reel configuration that applies and adheres a powdered thermoplastic material to the sheet. As the sheet is transferred from one reel it is heated, treated, and cooled before being rolled onto an opposite reel for storage until it is used. The machine is distinguishable for requiring a coating mechanism. 
     U.S. Pat. No. 4,217,379, issued on Aug. 12, 1980 to Silvano E. Salvador, describes a method for creating a simulated brick surface or the like which utilizes an adhesive tape with two series of marks for demarking the positions of a plurality of tapes to delineate simulated mortar lines. After a settable composition is applied to the surface, the tape is removed prior to the final setting of the composition. The method is distinguishable for attaching the horizontal stencil tapes with black, red and green marks on a wall with vertical strips attached to the color coded marks. The present inventive machine does not require color coding of the stencil. 
     U.S. Pat. No. 2,616,145, issued on Nov. 4, 1952 to Harry M. Dufford, describes a changeable four-sided pattern stencil with metal vertical and horizontal bars for use in molding decorative wall facings. The stencil is distinguishable for its variable sizing. 
     U.S. Pat. No. 5,243,905, issued on Sep. 14, 1993 to Ronald E. Webber, describes a stencil system and process for applying a decorative coating atop a substrate. Three sheets of transparent polycarbonate are processed to form an array of hexagons and rectangles. The stencils are distinguishable for requiring cutouts. 
     U.S. Pat. No. 5,535,671, issued on Jul. 16, 1996 to Hiroshi Kanno, describes a stencil duplicating machine applying a uniform tension to a stencil. The machine is distinguishable for application only to a printing drum. 
     U.S. Pat. No. 1,325,217, issued on Dec. 16, 1919 to Anthony Stokes, Jr., describes a heating apparatus for process embossing. The apparatus is distinguishable for its embossing structure. 
     U.S. Pat. No. 1,391,743, issued on Sep. 27, 1921 to Samuel Lipsius, describes a machine which is distinguishable for producing raised printing by drum printing. 
     U.S. Pat. No. 2,333,239, issued on Nov. 2, 1943 to Harry Fleisher et al., describes a spool truck for a screen printing apparatus which is distinguishable for its silk screening structure. 
     U.S. Pat. No. 5,813,329, issued on Sep. 29, 1998 to Hiroshi Tateishi et al., describes a printer for wrapping a stencil around a drum which is distinguishable for being limited to printing from a drum. 
     U.K. Patent Application No. 2,160,151 A, published on Dec. 18, 1985, describes a combination stencil duplicator and stencil imager which is distinguishable for its printing structure. 
     None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a automatic stenciling machine solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an automatic artificial brickwork stencil making machine having duplicate assembly lines which is small enough to fit on a coffee table-top like base. An upright roll of an adhesive coated plastic tape at one end of the base is fed through an upright plastic coated paper strip or tab containing cartridge to adhere the tabs to the pressure sensitive tape at predetermined intervals by a tamper element rotated by a drive spool connected by an endless drive chain. The tabbed tape continues on to an upright take up spool at the opposite end of the base. The take up spool is driven by a chain drive mechanism underneath the base. Several tape guides are positioned to maintain the direction of the travelling tape. 
     Accordingly, it is a principal object of the invention to provide a machine for making a brickwork stencil. 
     It is another object of the invention to provide an apparatus for automatically making a brickwork stencil with an adhesive coating on one side of an elongated tape. 
     It is a further object of the invention to provide an apparatus for automatically making a brickwork stencil with upright tabs spaced at a predetermined distance on the elongated tape. 
     Still another object of the invention is to provide an apparatus for automatically making a brickwork stencil in two production lines positioned on a limited base surface. 
     It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an environmental, perspective view of an automatic stenciling machine according to the present invention. 
     FIG. 2 is an elevational side view of the FIG. 1 machine with a detail of the tamper element. 
     FIG. 3 is a top plan view of the FIG. 1 machine. 
     FIG. 4 is a front elevational view of the stencil applied on a wall for application of a brick layer. 
     FIG. 5 is a side elevational view of the stencil being rolled up on a take up spool. 
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention is directed to a table-top automatic stenciling apparatus  10  wherein stencil assemblies  12  and  14  are positioned in parallel on a planar rectangular base  16  having a top surface  18 , a bottom surface  20 , a front end  22 , two parallel sides  24 ,  26 , and a rear end  28 . Legs  30  support the base corners. 
     The machine  10  will be described with reference to a single stencil assembly  12  or  14 . A roll of tape  32  having a width of ⅜ in. and having one side of the tape coated with a pressure sensitive adhesive is mounted on a tape holder reel  34  on a tape holder arm  36  proximate the front end  22  of the base  16 . An upright tab dispenser element  38  contains a stack of plastic coated paper tabs  40  which are 3 in. long, 0.01 in. thick and ⅜ in. wide. 
     In FIG. 2, a tamper element  42  is shown positioned underneath the dispenser element  38 , and is also shown in an enlarged detail view. The tamper element  42  passes through the base  16  for applying pressure against the tape  32  and the tab  40  at predetermined intervals. The tamper element  42  comprises a cylindrical rod  44  having rotatable bearings  46  on axles  48  at both ends of the rod  44 . The bearings  46  are oriented in directions 90° from each other. The tamper element  42  has a pin  50  which rides in a slot  52  of an apertured housing  54  which passes through the base  16 . A cam element  56 . offset from the tamper element  42  on a rotatable shaft  58 , and comprises a cam wheel with a wedge at the periphery of the wheel having a 15° angle lift and a 5° drop to raise the tamper element approximately 0.5 inch whenever the wedge contacts the lower bearing wheel  46 . When the upper bearing wheel  46  rises, it presses the tape  32  against the next available tab  40  in cartridge  38 , causing the tab  40  to adhere to the tape  32 . The diameter of the cam wheel and the position of the cam on the cam wheel are calculated to attach tabs  40  to tape  32  at precisely determined intervals. A sprocket wheel  60  on the end of the shaft  58  underneath the base  16  has an endless chain  62  which connects the sprocket wheel  60  to another sprocket wheel  64  on a shaft  65  of a drive spool  66  positioned above the base  16 . 
     The drive spool  66  coacts with a  1  inch diameter tape guide  68 , as depicted in FIG. 3, to flip the tape  32  from a horizontal orientation to a vertical orientation as it passes between the cartridge  38  and the take-up spool  70 . Rotation of the drive spool  66  causes the rotation of the sprocket wheel  60  which moves the tamper element  42  up and down. The take up spool  70  has a shaft  72  and a sprocket wheel  74  connected by an endless chain  76  to a sprocket wheel  78  on a D.C. motor  80  with a permanent magnet. The adhesive side of the tape  32  bears against drive spool  66 , thereby causing the cam element  56  to rotate via chain  62  and sprocket wheel  60 . Therefore, the rotation of the take up spool  70  moves the tape  32  through the machines  12  and  14  of the apparatus  10 . Operation of the motor  80  is controlled by a control box and wiring  79  as shown in FIG.  1 . 
     Two cylindrical tape guides  81  2 inches in diameter are shown in FIG. 1 as being located on either side of the tab dispenser element  38  for guiding the tape  32  between the dispenser  38  and drive spool  66 . 
     FIG. 5 shows the take up spool  70  on which a cardboard cylinder  82  is mounted to receive the tape  32  which has the tabs  40  added perpendicularly with a predetermined spacing of approximately 8 inches. The cardboard cylinder  82  can be removed from spool  70  and placed on a roller in order to apply the stencil  86  to a work surface. 
     In operation, a roll of tape  32  is placed on tape holder reel  34  and a portion of the tape  32  is threaded in a horizontal orientation through guides to tab dispenser  38 , the tape being positioned between dispenser  38  and upper bearing wheel  46 , thence through guides  81  and up to drive spool  66  and guide  68  where the tape  32  is flipped to a vertical orientation with the adhesive side bearing against drive spool  66 , and then to take-up spool  70 , where the tape  32  is adhered against cardboard cylinder  82 . The motor  80  is turned on, causing take-up spool  70  to rotate via chain  76 , pulling tape  32  from tape holder reel  34 . As tape advances past the drive spool  66 , the spool  66  rotates, causing cam  56  to rotate via chain  62 . As the cam passes under the lower bearing wheel  46 , the cylindrical rod  44  rises to press upper bearing wheel  46  against tape  32  to apply the next tab  40  to the tape at a predetermined interval. In this manner, the two stencil assemblies  12  and  14  can prepare to stencil rolls  86  in about two minutes. 
     FIG. 4 illustrates how a wall  84  is configured to place the stencil  86  on the wall. A first coat of a colored (preferably gray) masonry cement mixture  88  is applied on the wall  84 . Chalk lines  90  are marked vertically at 4 and 8 inch intervals to locate the tabs  40 . The stencils  86  are placed on appropriate horizontal chalk lines in staggered formation with the tabs aligned with the horizontal chalk lines  90 . Then a brick colored mixture  92  is layered over the stencil  86  and after drying, the stencil is removed to result in a brick wall facing. It has been estimated that this brick facing can be applied for one-third of the cost of using real bricks. The bricks can be spray painted with different alternating colors. 
     The following exemplary dimensions and compositions of the apparatus  10  are: 
     Base  12 : 16 in. ×30 in. ×0.5 in. aluminum. 
     Tab dispenser element  38 : 7.5 in. in height, 4 in. wide and 1 in. 
     thick; aluminum. 
     Tape holder reel  34 : 3.25 inch diameter aluminum wheel. 
     Tape holder arm  36 : 8 inch long, aluminum. 
     Drive spool  66 : 2 in. diameter, aluminum. 
     Tape guides  68 ,  81 : 1 and 2 in. diameters, aluminum. 
     Sprocket wheels  64 ,  74 ,  78  and shafts: steel. 
     Cam element  56  and tamper element  42 : steel. 
     Take up spool  70 : plastic with steel grab arms. 
     Legs  30 : steel. 
     It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims.