Patent Publication Number: US-2020290056-A1

Title: Energy-saving auto feed shredder

Description:
FIELD OF INVENTION 
     The present invention relates generally to a paper shredder, and more particularly to an energy-saving auto feed shredder. 
     BACKGROUND TO THE INVENTION 
     As known to all, in a paper shredder to shred paper, there are multiple cutting blades and spacers installed on two parallel rotary shafts in relative motion. The rotary shafts are driven by a motor and gear box to slice the paper fed into the shredder. To prevent failure of the motor of the paper shredder due to overload, there is a preset limit for sheet capacity. That is to say, when a lot of paper needs to be destroyed, the amount of paper put into the shredder each time by the user must be lower than the maximum sheet capacity. Batch-by-batch manual feeding of the paper into the shredder is boring and time-wasting. Therefore, auto feed shredders with the function of automatic paper feeding are developed to meet the demand for large-quantity paper shredding. 
     For example, in the U.S. Pat. No. 9,884,323 Patent disclosed in FIG. 1A and FIG. 1B, when the openable cover  14  of the auto feed shredder is opened, there can be seen a feeder base or compartment  34 , to hold stack of standard sized paper, and in the middle of the bottom of the feeder base or compartment  34 , there is a feeder slot  28 . Once there is paper passing by the feeder slot  28 , the shredder mechanism  36  below the feeder slot will be activated to cut the paper into debris, which then falls into the waste bin. The bottom of the cover  14  is configured with pressure plates  32 , when the cover  14  is closed, the pressure plates  32  will apply a pressure on the stack of paper placed inside the feeder base or compartment. On both sides of the feeder slot  28 , there are feeding mechanisms  30  in relative rotary motion. The feeding mechanisms can be a plurality of symmetrically arranged rubber rollers, or a roller-belt assembly. When touching the bottom of the stack of paper inside the feeder base or compartment  34 , the feeding mechanisms  30  in relative rotary motion will capture and pull the paper sheets at the bottom of the stack and fold them above the feeder slot  28 , and then deliver them to the shredder mechanism  36  below the slot. Repeatedly, new paper sheets at the bottom of the stack are captured, pulled, folded and delivered by the feeding mechanism, until all the paper is shredded. 
     Auto feed shredders having similar functions as described above are also disclosed in  FIG. 2 , U.S. Pat. No. 7,387,268; FIG. 3, U.S. Pat. No. 7,658,342; FIG. 4, U.S. Pat. No. 8,336,794. 
     Referring to  FIG. 5 , said conventional auto feed shredders share the same characteristic that the feeder slot  28  in the middle of the feeder base or compartment  34  is in nearly parallel orientation with the folding line Py of the longer side L of the stack of paper P placed inside the feeder base or compartment  34 . With such a design, the longer side L of the stack of paper P can be captured, pulled, folded and delivered by the feeding mechanism. That is to say, when passing through the shredder mechanism (not shown in the drawing), the motion range of the paper sheets captured from the bottom of the stack of paper P to be shredded is half of the longer side (½ L) of the paper to be shredded. Taking the longer side (29.7 cm) of an A4 sheet for example, the length is 14 cm or so after folding. Therefore, the time to shred an A4 paper sheet is the time for the shredder mechanism to cut ½ L i.e., 14 cm. 
     It can be concluded that, the time for the shredder mechanism to cut the paper sheets to be shredded has a direct proportional relationship with the motion range of the paper sheets to be shredded when passing through the shredder mechanism after folding. In another word, the shorter motion range of the folded paper sheets to be shredded passing through the shredder mechanism, the shorter time is needed to shred the paper. The accumulated results will dramatically reduce the operation time of the motor and save considerable energy. 
     SUMMARY OF THE INVENTION 
     The main object of the present invention is to provide an energy-saving auto feed shredder, wherein, the feeder slot is in nearly parallel orientation with the folding line of the shorter side of the stack of paper placed inside the feeder base or compartment, so that the shorter side of the stack of paper can be captured, pulled, folded and delivered to the shredder mechanism by the feeding mechanism. 
     To accomplish the above object, the present invention provides an energy-saving auto feed shredder, which includes an openable cover as configured in a conventional auto feed shredder with a pressing device configured on the cover. Once the cover is open, other components of the present invention are exposed, such as a feeder base or compartment to place the stack of paper, a feeder slot in the middle of the feeder base or compartment, feeding mechanisms on both sides of the feeder slot, and a shredder mechanism below the feeder slot; when the cover is closed, the pressing device applies a pressure on the stack of paper inside the feeder base, and the feeding mechanisms in relative motion on both sides of the feeder slot captures and pulls the sheets at the bottom of the stack of paper under pressure, and force them to fold toward the feeder slot, and be delivered to the shredder mechanism. Repeatedly, new sheets of paper are captured, pulled, folded and delivered by the feeding mechanism, until the whole stack of paper is shredded. Wherein, the feeder slot is in nearly parallel orientation with the folding line of the shorter side of the stack of paper inside the feeder base, so that the shorter side of the stack of paper can be captured, pulled, folded and delivered to the shredder mechanism by the feeding mechanism. 
     As the feeder slot is intentionally designed to be in nearly parallel orientation with the folding line of the shorter side of the stack of paper placed inside the feeder base or compartment, the shorter side of the stack of paper will be captured, pulled, folded and delivered to the shredder mechanism by the feeding mechanism; Taking the shorter side (21 cm) of an A4 paper sheet as an example, the length becomes 10.5 cm after folding. Therefore, the time for shredding an A4 paper sheet is the time used by the shredder mechanism to cut the length of ½ W (namely 10.5 cm). 
     In a conventional auto feed shredder, the feeder slot is in nearly parallel orientation with. the folding line of the longer side of the stack of paper, so that the longer side of the stack of paper is captured, pulled, folded and delivered by the feeding mechanism; In comparison, in the present invention, the feeder slot is intentionally designed to be in nearly parallel orientation with the folding line of the shorter side of the stack of paper placed inside the feeder base or compartment, so that the shorter side of the stack of paper will be captured, pulled, folded and delivered to the shredder mechanism by the feeding mechanism; Taking an A4 paper sheet for example, the cutting range of a conventional auto feed shredder is 14 cm, while the present invention has an obviously much shorter cutting range (10.5 cm). Therefore, to shred an A4 paper sheet, the present invention will save about 25% of the time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A ,  FIG. 1B  are structural views of U.S. Pat. No. 9,884,323; 
         FIG. 2  is a structural view of U.S. Pat. No. 7,387,268; 
         FIG. 3  is a structural view of U.S. Pat. No. 7,658,342; 
         FIG. 4  is a structural view of U.S. Pat. No. 8,336,794; 
         FIG. 5  is a schematic view showing the folding line of the longer side of the paper sheet is in nearly parallel orientation with the feeder slot when a stack of paper is placed inside the feeder base or compartment of a conventional auto feed shredder; 
         FIG. 6  is a schematic view showing the folding line of the shorter side of the paper sheet is in nearly parallel orientation with the feeder slot when a stack of paper is placed inside the feeder base or compartment of the first embodiment of the present invention; 
         FIG. 7  is a schematic view showing the relative positions of the stack of paper and the feeder base or compartment in the first embodiment of the present invention; 
         FIG. 8  is a schematic view showing the relative positions of the folding line of the shorter side of the stack of paper and the feeder slot in the first embodiment of the present invention; 
         FIG. 9A  is a schematic view showing the relative positions of the folding line of the shorter side of the stack of paper and the feeder slot in the second embodiment of the present invention; 
         FIG. 9B  is a schematic view showing the relative positions of the folding line of the shorter side of the stack of paper and the feeder slot in the third embodiment of the present invention; and 
         FIG. 9C  is a schematic view showing the relative positions of the folding line of the shorter side of the stack of paper and the feeder slot in the fourth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The features of the present invention can be readily understood by referring to the drawings and detailed descriptions of preferred embodiments of the present invention. 
     The present invention is an energy-saving auto feed shredder, which includes an openable cover  14  as configured in a conventional auto feed shredder (see  FIG. 1  to  FIG. 5 ) with a pressing device  32  configured on the cover. Once the cover  14  is open, other components of the present invention are exposed, such as a feeder base or compartment  34  to place the stack of paper, a feeder slot  28  in the middle of the feeder base or compartment  34 , feeding mechanisms  30  on both sides of the feeder slot  28 , and a shredder mechanism  36  below the feeder slot  28 . When the cover  14  is closed, the pressing device  32  applies a pressure on the stack of paper inside the feeder base or compartment  34 , and the feeding mechanisms  30  in relative motion on both sides of the feeder slot  28  captures and pulls the sheet at the bottom of the stack of paper under pressure, and force it to fold. toward the feeder slot  28 , and be delivered to the shredder mechanism  36 . Repeatedly, new sheet of paper are captured, pulled, folded and delivered by the feeding mechanism, until the whole stack of paper is shredded. 
     Referring to  FIGS. 6-8 , the feeder slot  28  is in nearly parallel orientation with the folding line Px of the shorter side W of the stack of paper P inside the feeder base or compartment  34 , so that the shorter side W of the stack of paper P can he captured, folded and delivered to the shredder mechanism by the feeding mechanism. 
     In the present invention, the folding line Px of the shorter side W of the stack of paper P is made to be in nearly parallel orientation with the feeder slot  28 , so that the shorter side W of the stack of paper P will be captured, pulled, folded and delivered to the shredder mechanism by the feeding mechanism. Taking the shorter side (21 cm) of an A4 paper sheet as an example, the length becomes 10.5 cm after folding. Therefore, the time for shredding an A4 paper sheet is the time used by the shredder mechanism to cut the length of ½ W (namely 10.5 cm). 
     In comparison, referring to  FIG. 5 , in a conventional auto feed shredder, the longer side L of the stack of paper P is in nearly parallel orientation with the feeder slot  28 , so that the longer side L of the stack of paper P is captured, pulled, folded and delivered by the feeding mechanism. Taking the longer side (2.9.7 cm) of an A4 paper sheet as an example, the length becomes 14 cm or so after folding. Therefore, the time for shredding an A4 paper sheet is the time used by the shredder mechanism to cut the length of ½ L (namely 14 cm or so). 
     In the case of an A4 paper sheet, the cutting range of a conventional auto feed shredder is 14 cm or so, while the present invention has an obviously much shorter cutting range (10.5 cm). Therefore, to shred an A4 paper sheet, the present invention will save about 25% of the time comparing to a conventional auto feed shredder. 
     Based on the above concept and principle, slight alterations can be made to the present invention. In  FIGS. 6-8 , the feeder slot  28  is configured in the middle of the feeder base or compartment  34 . In the second embodiment and the third embodiment disclosed in  FIG. 9A  and  FIG. 9B , the feeder slot  28  is configured at the position with a deviation from the middle of the feeder base or compartment  34 . Although the feeder base or compartment  34  has an offset distance D 1 , D 2  from the folding line Px of the shorter side of the stack of paper, the feeder slot  28  is still in nearly parallel orientation with the folding line Px of the shorter side of the stack of paper P placed inside the feeder base or compartment  34 ; 
       FIG. 9C  discloses a fourth embodiment of the present invention, wherein, the feeder slot  28  is configured with an offset angle from the middle of the feeder base or compartment  34 ; so that the feeder slot  28  forms an offset angle  0  with the folding line Px of the shorter side of the pressed stack of paper P placed inside the feeder base or compartment  34 . 
     The foregoing description of the invention includes preferred embodiments thereof. Modifications may be made thereto without departing from the scope of the invention. To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.