Autofeed paper shredder with input drawer

Abstract

An auto-feed paper shredder is configured for placement below the surface of a desk. The auto-feeder consists of a drawer located on the front surface of the shredder. This drawer is slid out to insert a stack of documents to be shredded. When the door is slid back into the shredder and the shredding system is activated, feed rollers draw sheets of paper either from the top or the bottom surface of the stack and feed the sheets into a conventional paper shredding mechanism. An input slot is provided to insert single sheets of paper when the auto-feeder is not being used.

Claims

1. An auto-feed paper shredder configured to fit under a desktop comprising: a housing containing a paper shredding mechanism; an input slot on a surface of the housing disposed so that sheets of paper can be manually inserted when the auto-feed paper shredder is placed beneath a desktop; a horizontally oriented, slidable drawer insertable into a front surface of the paper shredder for holding a stack of paper to be shredded; and an auto-feed apparatus configured to remove sheets of paper from the stack and convey the sheets to the paper shredding mechanism when the slidable drawer is inserted into the paper shredder.

2. The auto-feed paper shredder according to claim 1, wherein the auto-feed apparatus comprises at least one roller or belt for removing sheets of paper from an upper surface of the stack.

3. The auto-feed paper shredder according to claim 2, wherein the at least one roller or belt has an upper position to allow the drawer to be inserted into or removed from the paper shredder and a lower position wherein the at least one roller or belt contacts the upper surface of the stack for removing sheets of paper from the stack.

4. An auto-feed paper shredder configured to fit under a desktop comprising: a housing containing a paper shredding mechanism; an input slot on a surface of the housing disposed so that sheets of paper can be manually inserted when the auto-feed paper shredder is placed beneath a desktop; a horizontally oriented, slidable drawer insertable into a front surface of the paper shredder for holding a stack of paper to be shredded; and an auto-feed apparatus comprising at least one roller or belt configured to remove sheets of paper from an upper surface of the stack and convey the sheets to the paper shredding mechanism when the slidable drawer is inserted into the paper shredder.

5. The auto-feed paper shredder according to claim 4, wherein the at least one roller or belt has an upper position wherein the roller or belt does not contact the upper surface of the stack to allow the drawer to be inserted into or removed from the paper shredder and a lower position wherein the roller or belt contacts the upper surface of the stack for removing sheets of paper from the stack.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a drawing of a prior art shredder configured for placement below the surface of a desk;

(2) FIG. 2 shows a drawing of the current invention, an auto-feed shredder configured for placement below a desk surface.

(3) FIG. 3 shows a cross-sectional view of the shredder of FIG. 2 with at least one roller in an upper position; and

(4) FIG. 4 shows a cross-sectional view of the shredder of FIG. 2 with at least one roller in a lower position contacting an upper surface of a stack of paper.

DETAILED DESCRIPTION OF THE INVENTION

(5) The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide a paper shredder for placement below a desk surface and including a mechanism to shred sheets of paper pulled from a stack of sheets placed within a drawer integral to the shredder.

(6) FIG. 1 shows a prior art paper shredder configured for placement below a desk surface. The shredder 10 includes an input slot 12 that is located on either a front surface or a beveled surface which joins the front surface of the unit to the top surface. Traditionally, the input slot 12 would be located on an upper surface of the shredder body, but when a shredder is located below a desk surface, a slot on the upper surface of the shredder is no longer accessible.

(7) The present invention enables an auto-feed shredder as has been described above to be conveniently be place below a desk surface. As shown in FIGS. 2-4, the device has an input slot 12 on the front surface, on a top bevel or near the front of the top so that when the unit is slid beneath a desk surface, the input slot is still accessible. Internally, the unit is much like a traditional shredder having a shredding mechanism 16 of spaced apart cutter blades disposed on two counter-rotating shafts disposed within a housing 20. A throat or chute conducts the paper sheets into the shredding mechanism 16 where they are shredded by the counter-rotating blades. In addition to the typical input slot 12, the unit has an input drawer 22 for inputting an entire stack of papers 100 to be processed by an auto-feed system 18. To use the drawer 22, it is slid out from the unit and the stack of paper documents is loaded into the drawer. Then, the drawer is slid back into the unit, and the shredding commences. It will be appreciated that the input slot 12 can be above or below (or even feed directly into) the input drawer 22.

(8) The drawer auto-feed 18 can operate in several different ways. In one embodiment, the bottom interior surface of the tray is equipped with a biasing plate that becomes depressed when a stack of paper 100 is inserted into the drawer 22. Similar to the structure of paper trays in copiers and printers, when a stack of paper is loaded into the tray, the spring-loaded biasing plate becomes depressed by the weight of the paper stack. When the user presses down to insert the stack, the biasing plate locks into place so that it no longer exerts upward force on the stack. When the drawer 22 is inserted into the shredder 10, the lock on the biasing plate is automatically released so that the biasing plate again exerts an upward force on the paper stack thereby bring the paper into contact with a feed roller or belt 14 that draws single sheets of paper, one at a time, off the top of the stack 100 and feeds them into the throat of the shredding mechanism 16. Sheets of paper inserted through the input slot 12 move directly into the throat of the shredder 10 generally without assistance of the feed rollers. For that reason it is usually preferred to place the input slot 12 above the drawer 22 so that inserted sheets can feed directly into the throat. It will be appreciated that to allow the paper drawer to be readily removed for reloading, the feed roller or feed belt 14 is located above the paper stack 100 in a position not to interfere with removal of the tray. During the paper feed cycle, the belt or roller 14 temporarily moves into position to contact the upper surface 102 of the paper stack 100.

(9) In an alternate embodiment the drawer has a slot in its bottom though which the counter-rotating feed rollers of the type disclosed in U.S. Pat. No. 8,074,912 pass to contact the bottom sheet of the stack so as to suck sheets from the bottom of the stack and feed them into the shredder throat. A pair of belts moving in opposite directions can take the place of the rollers. The shredder is constructed so that when the feed rollers are in an active contacting position, the drawer is locked closed. When the feed rollers are inactive, they retract and the drawer unlocks so that it can be refilled. The locking of the drawer can be automatic or under manual control. In a manual system, when the drawer is inserted into the shredder, a catch locks the drawer in position and a sensor is activated to determine if the drawer contains paper. If it does contain paper, the feed rollers move up into contact with the lower surface of the paper stack. When the user desires to withdraw the drawer 14 to insert additional paper, the user presses a switch or a lever that unlocks the catch and simultaneously causes the feed rollers to retract allowing the drawer 14 to be withdrawn.

(10) It will be appreciated that for such a bottom feed roller configuration to operate reliably, the drawer must be equipped with means to uniformly press the stack down onto the feed rollers. This can be accomplished either by a spring-loaded, hinged bias plate under which the sheets of paper are placed when one loads the drawer or by a mechanically driven pressure plate that descends into the drawer when it is inserted into the shredder. The same sensor that controls movement of the feed rollers could also control the mechanically driven pressure plate so that like the feed rollers (or moving belts) the pressure plate automatically retracts when the drawer is slid out for loading purposes. The input slot 12 is configured so that inserted sheets of paper are deflected to the feed rollers when the drawer is empty.

(11) To review operation of an automatic embodiment of the drawer loading under desk paper shredder: to shred a stack of documents, the input drawer is slid out from the unit. In a preferred embodiment, the entire drawer can be removed from the shredder so that loading documents can be conveniently accomplished on the user's work desk. The drawer is not unlike an input drawer for a copier, fax machine or printer. The drawer is equipped with guides so the tray can be adjusted to accept paper stacks of several standard dimensions (e.g., letter, legal and A4). The drawer has an opening slot in its lower surface for the feed rollers. The drawer is loaded with a stack of documents and slid back into the shredder. Assuming that the shredder is set to automatic or on a sensor determines whether or not there are documents in the drawer. If there are, the drawer is locked and the feed rollers ascend to make contact with the lower sheet of the paper stack. At the same time any upper surface pressure device present activate to press the paper stack into contact with the rollers. The rollers then activate and sheets of paper are pulled from the bottom of the stack and fed into the input throat of a shredding mechanism. A sensor in the throat detects the paper and starts the shredding mechanism. Shredding continues until the stack is exhausted. When there is no more paper being fed into the input throat, the shredding mechanism stops. The stack sensor determines that the drawer is empty so the feed rollers deactivate and move downward and into a safe position (at the same time any upper surface pressure device also withdraws) so that the drawer can be opened for addition of more paper.

(12) The following claims are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted and also what incorporates the essential idea of the invention. Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope of the invention. The illustrated embodiment has been set forth only for the purposes of example and that should not be taken as limiting the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.