Abstract:
A paper tamping mechanism comprising a mechanism depositing sheets in a stack; a tamping blade adjacent to the stack; said tamping blade is movable towards said stack in order to strike and tamp a sheet deposited on the stack; the tamping blade means is movable away from the stack after the sheet has been struck; a magnet is mounted on the blade and a plurality of magnets are provided adjacent to the blade in a wheel which moves magnets relative to said magnet in the blade.

Description:
BACKGROUND 
     The present invention relates to a paper tamping mechanism and more particularly to a paper tamping mechanism which assures that sheets deposited on a stack of sheets are tamped down so that the uppermost sheet lies flat on the stack. 
     Handling of paper sheets often involves depositing individual sheets of paper in an accumulating area. The sheets are deposited one on top of the other to form a stack in the accumulating area. Since the individual sheets are light and are fed from a source spaced from the accumulating area, the sheet being deposited sometimes may not lie flat on the stack. If this occurs, it may interfere with the transfer of the stack of sheets to some other unit or with some additional function the stack may be subjected to. 
     OBJECTS 
     The present invention avoids this problem and has for one of its objects the provision of an improved paper tamping mechanism for assuring that the topmost sheet deposited on a stack will be tamped down so that it will lie flat on the stack. 
     Another object of the present invention is the provision of an improved paper tamping mechanism which is operated with a minimum of moving parts. 
     Another object of the present invention is the provision of an improved paper tamping mechanism which is simple to operate and inexpensive to manufacture. 
     Other and further objects will be obvious upon the understanding of the illustrative embodiment about to be described, or which will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
     These objects are accomplished by providing a tamping blade adjacent the stack which moves down to strike the topmost sheet as soon as it is deposited on the stack in order to flatten the sheet on top of the stack. In the preferred embodiment of the invention, the tamping blade has a permanent magnet therein which reacts with permanent magnets on a rotatable magnetic wheel or cylinder adjacent thereto. The permanent magnet in the tamping blade is of one polarity and the permanent magnets in the magnetic wheel are alternately magnets with positive and negative polarities. When the magnetic wheel is rotated, as soon as the permanent magnet on the wheel with a polarity the same as the polarity of the permanent magnet in the tamping blade are adjacent to each other, the magnets repel each other and the tamping blade will move down and strike the topmost sheet in order to lay it perfectly flat on the stack. As the magnetic wheel continues to rotate and a permanent magnet in the wheel of a polarity different from the polarity of the tamping blade magnet are adjacent to each other, the magnets will attract each other and the tamping blade will move up away from the stack in order to permit another sheet to be deposited on top of the stack. 
    
    
     DRAWINGS 
     A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification wherein: 
     FIG. 1 is a simplified and diagrammatic side view of a tamping mechanism made in accordance with the present invention showing the tamping blade being moved away from the stack. 
     FIG. 2 is a view similar to FIG. 1 showing the tamping blade being moved toward the stack. 
     FIG. 3 is a simplified and diagrammatic perspective view of the tamping mechanism of the present invention. 
     FIG. 4 is a simplified and diagrammatic side view of a modification of the present invention. 
    
    
     DESCRIPTION 
     Referring to the drawings, sheets of paper P are delivered by any well known means one by one on top of each other onto an accumulating area A to form a stack S of sheets P. Since the topmost sheet P is dropped onto the stack S from a source (not shown), the sheet P may not lie flat on top of the stack S. In order to prevent this, a tamping blade  1  is pivotally mounted adjacent the stack S. The tamping blade  1  is flat, thin and elongated and has a top face  4 , a bottom face  5 , front edge  2  and a rear edge  3 . The tamping blade  1  is pivotally mounted along its rear edge  3  to a pivot  6  which permits the tamping blade  1  to move up and down around the pivot  6 . As soon as a sheet P is deposited on top of the stack S, the tamping blade  1  is moved down around pivot mechanism  6  so that it strikes the topmost sheet P to lay it flat on top of the stack S As soon as this occurs the tamping blade  1  is moved up around pivot mechanism  6  away from the stack S so that another sheet E can be deposited on top of the stack S and the operation is repeated. 
     In the preferred embodiment of the invention, the tamping blade  1  has a permanent magnet  10  therein of a particular polarity which in the drawings has been indicated as being of positive polarity. The permanent magnet  10  is shown as being flat and elongated for convenience of illustration. However, the permanent magnet  10  may assume different shapes and sizes without departing from the invention. In the drawings, a single magnet  10  has been shown, however, it will be understood that several magnets  10  may be disposed along the length of the blade  1  at special intervals or a single magnet  10  may extend along substantially the entire length of the blade. A magnetic wheel or cylinder  11  is rotatably mounted adjacent the top face  4  of the tamping blade  1 , i.e. the face of the tamping blade  1  away from the stack S Preferably, the magnetic wheel  10  is a cylinder opposite blade  1 . The magnetic wheel or cylinder  11  has a plurality of permanent magnets  12  and  13  spaced from each other around its periphery  14  and is rotated around an axis  15 . The polarity of the permanent magnets  12  and  13  are in alternating sequence around the periphery  11  so that a positive polarity magnet  12  is followed by a negative polarity magnet  13  which is followed by a positive polarity magnet  12 . The permanent magnets  12  and  13  have been shown as being elongated and approximately the same length as permanent magnet  10  on the blade  1 . However, the magnets  12  and  13  may assume different shapes and sizes if desired. The position of the magnets  12  ad  13  around the cylinder  11  are shown as being positioned opposite and adjacent to the permanent magnet  10  on the blade  1 . However, all that is necessary is for the magnets  12  and  13  and  10  to be close enough to each other for the magnetic fields of each to react to each other. The magnets  12  and  13  may be single magnets spaced around the perimeter of the cylinder  11  as shown in the drawings or a plurality of axially aligned magnets along the periphery of the cylinder  11  or elongated single magnets extending along substantially the entire length of cylinder  11 . 
     In the drawings, four magnets  12 - 13  of alternating sequential polarity are shown on the magnet wheel  11 . However, the number of magnets  12 - 13  on the wheel  11  may be changed without departing from the invention. 
     The magnetic wheel or cylinder  11  is rotated around its axis  15  so that the permanent magnets  12  and  13  alternately move past the permanent magnet  10  on the tamping blade  1 . When the negative permanent magnet  13  in the wheel  11  is adjacent to the positive permanent magnet  10  in the tamping blade  1 , the two magnets will attract each other thereby pulling the tamping blade  1  around its pivot  6  away from the stack S and toward the wheel  11  (FIG.  1 ). The stack S is now free to receive a new sheet P to be deposited thereon. As the wheel  11  continues to rotate the positive permanent magnet  12  in the wheel  11  moves to a position adjacent to the positive magnet  15  in the tamping blade  1 . The two magnets now repel each other thereby moving the tamping blade  1  around its pivot  6  away from the wheel  11  and downwardly toward the stack S to strike the top sheet P that has just been deposited on the stack S As the wheel  11  continues to rotate, the next negative permanent magnet  13  again moves adjacent to the positive permanent magnet  10  in the tamping blade  1  in order to pull the tamping blade  1  away from the stack S thereby permitting another sheet P to be placed on top of the stack S. The rotation of the wheel  11  is synchronized with the deposition of a sheet P on top of the stack S so that whenever a sheet P is to be deposited on the stack S, the tamping blade  1  is moved up away from the stack S and after the sheet P is deposited on the stack S, the tamping blade  1  is moved down on top of the stack S. 
     It will be understood that although the drawings illustrate the permanent magnet  10  on the tamping blade  1  to be positive polarity, it is within the purview of the present invention for the permanent magnet  10  in the tamping blade  1  to be of negative polarity in which event when the positive permanent magnet  12  on the wheel  10  is adjacent the tamping blade  1 , it will pivot down over the stack S and when the negative permanent magnet  13  is opposite the tamping blade  1 , it is pivoted away from the stack S. 
     It will also be understood that while permanent magnets  10 - 12 - 13  have been disclosed in describing the present invention, electromagnets may also be used without departing from the invention. 
     FIG. 4 shows another embodiment of the present invention. In this embodiment, the magnetic wheel  20  has permanent magnets  21  of the same polarity as the polarity of the permanent magnet  22  on the tamping blade  30  so that when the two permanent magnets  22  and  21  are adjacent to each other, the tamping blade  30  is pivoted down to flatten the top sheet P onto the stack S. In order to move the tamping blade  30  away from the stack S to permit another sheet P to be deposited on the stack S, spring  23  is provided having one end  31  mounted on the tamping blade  30  at  32  and its other end  33  attached to a frame member  34 . When in its normally contracted condition, the spring  23  is biased toward the frame  34  to pull the blade  30  away from the stack S. As soon as the magnets  21  and  22  are adjacent to each other, the magnets  21  and  22  repel each other and the tamping blade  30  is moved down against the bias of the spring  23  thereby stretching the spring  23  to strike the topmost sheet P so that it lays flat on the stack S. When the permanent magnet  21  in the wheel  20  is moved away from the permanent magnet  22  in the tamping blade  30  and the two magnets  21 - 22  no longer react with each other, the spring  23  will contract to pull the blade  30  away from the stack S. Again, although the drawings show the magnets  21  and  22  being of positive polarity, it is within the purview of the present invention that the permanent magnets  21  and  22  in both the magnetic wheel  20  and the tamping blade  30  to be of negative polarity. 
     It will thus be seen that the present invention provides an improved paper tamping mechanism which assures that the top sheet deposited on a stack will be tamped down to lie flat on the stack which operates with a minimum of moving parts and which is simple to operate and inexpensive to manufacture. 
     An many varied modifications of the subject matter of this invention will become apparent to those skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only an provided in the claims appended hereto.