1. Field of Invention
The invention relates to a shredder. In particular, the invention relates to an anti-jam device for the shredder. In the AUTO mode, the passage width provided by the anti-jam device is exactly the maximum thickness of paper that can be fed each time. In the REV mode, the anti-jam device provides a larger passage width for the paper to be backed out easily.
2. Related Art
To prevent such documents as legal files, receipts, invoices, credit card numbers, research reports, or personal financial information (e.g., credit card and phone bills) from being released, it is common to destroy them using a shredder. Therefore, the shredder has become an indispensable device for both business and home applications.
The action principle of a shredder for shredding paper is to dispose several cutting blades on two rotary shafts with spacers in between. A motor and a gearbox are employed to drive the two parallel rotary shafts that rotate in opposite directions. They provide a shearing force on passing paper to cut it into small stripes.
The motor load and the strength of the cutting blades and rotary shafts limit the sheet capacity allowed by the shredder each time. That is, when many paper sheets need to be destroyed, the user has to limit the amount of paper each time. Otherwise, there may be paper jam occurring to the rotary shafts. Therefore, in order not for the user to put in too much paper at a time, it is necessary to provide an anti-jam device that automatically restricts the number of sheets.
An objective of the invention is to provide an anti-jam device that restricts the number of sheets each time. In the auto mode, the provided passage width is exactly the maximum thickness of paper that can be fed each time. In the rev mode, the anti-jam device provides a larger passage width for the paper to be backed out easily.
In accord with the above-mentioned objective, the disclosed anti-jam device comprises a movable element and a fixing element disposed above the rotary shafts of the shredder. The movable element is a pair of rod parallel to the rotary shafts, with both ends in the holes preformed on the fixing element. When the shredder is in its auto mode, the passage width provided by the rap between the rods is exactly the maximum thickness of paper that can be fed each time. In the rev mode, the rods are pushed upwards by the paper to render a larger passage width for the paper to be backed out easily.
The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
The discloses shredder includes a housing 30, a shredder opening 31 on the top surface of the housing for material such as paper to be fed in, and a shredder mechanism disposed inside the housing 30 for shredding the material. The shredder mechanism includes cutting blades mounted on the rotary shafts 40. A motor and a gearbox drive the two parallel rotary shafts that run in opposite directions. The material being fed is then to cut into chips. The disclosed anti-jam device is disposed between the rotary shafts 40 and the shredder opening 31, composed of a movable element 10 and a fixing element 20.
In the first embodiment, the rods in the movable element 10 can be metal or plastic hollow tubes or solid bars. To save the material, the second embodiment shown in
The symmetrically disposed plastic rings 13 in the movable element 10 of the second embodiment can be replaced by plastic or metal rollers 12, as shown in
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
Number | Name | Date | Kind |
---|---|---|---|
6113017 | Tsai | Sep 2000 | A |
6213417 | Schwelling | Apr 2001 | B1 |
6682006 | Lee | Jan 2004 | B2 |
7156330 | Lo | Jan 2007 | B1 |