Shredder with thickness detector

Abstract

A shredder is disclosed. The shredder includes a housing having a throat for receiving at least one article to be shredded, and a shredder mechanism received in the housing and including an electrically powered motor and cutter elements. The shredder mechanism enables the at least one article to be shredded to be fed into the cutter elements. The motor is operable to drive the cutter elements so that the cutter elements shred the articles fed therein. The shredder also includes a detector that is configured to detect a thickness of the at least one article being received by the throat, and a controller that is operable to perform a predetermined operation responsive to the detector detecting that the thickness of the at least one article is at least equal to a predetermined maximum thickness.

What is claimed is: 
     
       1. A shredder comprising:
 a housing having a throat open to an exterior of the housing for permitting a user to feed at least one article to be shredded;   a shredder mechanism received in the housing and including an electrically powered motor and cutter elements, the shredder mechanism enabling the at least one article fed into the throat to be shredded to be fed into the cutter elements and the motor being operable to drive the cutter elements in a shredding direction so that the cutter elements shred the articles fed therein;   a thickness detector configured to detect a thickness between opposing major surfaces of the at least one article to be shredded being received by the throat;   a maximum thickness indicator having a visual or audible output and configured to indicate a visual or audible signal to a user of the shredder via the visual or audible output;   a controller configured to actuate the maximum thickness indicator and indicate the visual or audible signal to the user via the visual or audible output responsive to the detector detecting that the thickness of the at least one article is at least equal to a predetermined maximum thickness.   
     
     
       2. A shredder according to  claim 1 , wherein the maximum thickness indicator includes a light that is illuminated to indicate the signal to the user. 
     
     
       3. A shredder according to  claim 1 , wherein the maximum indicator includes an audible alarm that audibly indicates the signal to the user. 
     
     
       4. A shredder according to  claim 1 , wherein the controller is also configured to prevent the motor from driving the cutter elements in the shredding direction responsive to the detector detecting that the thickness of the at least one article is at least equal to the predetermined maximum thickness. 
     
     
       5. A shredder according to  claim 1 , wherein the maximum thickness indicator is included in a progressive indicator system coupled to the controller,
 wherein the progressive indicator system is configured to indicate a detected thickness of the at least one article within a range of thicknesses up to and including the predetermined maximum thickness.   
     
     
       6. A shredder according to  claim 5 , wherein the progressive indicator system has a plurality of indicators, wherein each indicator is associated with a corresponding predetermined thickness of the at least one article within said range, the plurality of indicators including the maximum thickness indicator corresponding to the predetermined maximum thickness,
 wherein the progressive indicator system activates the indicator associated with its respective corresponding predetermined thickness based on the detector detecting that the thickness of the at least one article is at least equal to the corresponding predetermined thickness.   
     
     
       7. A shredder according to  claim 6 , wherein the progressive indicator system comprises a plurality of lights. 
     
     
       8. A shredder according to  claim 1 , wherein the detector comprises a contact member that extends into the throat and is actuated in response to the article being inserted into the throat. 
     
     
       9. A shredder according to  claim 8 , wherein the detector further comprises a strain gauge configured to measure movement of the contact member and communicate the movement to the controller. 
     
     
       10. A shredder according to  claim 8 , wherein the detector further comprises a piezoelectric sensor configured to measure movement of the contact member and communicate the movement to the controller. 
     
     
       11. A shredder according to  claim 8 , wherein the detector further comprises an optical sensor configured to measure movement of the contact member and communicate the movement to the controller. 
     
     
       12. A shredder according to  claim 11 , wherein the optical sensor comprises an infrared LED and a dual die infrared receiver configured to detect the direction and amount of the movement. 
     
     
       13. A shredder according to  claim 1 , wherein the detector is also configured to detect a presence of the at least one article to be shredded being received by the throat, and wherein the controller is configured to operate the motor to drive the cutter elements in the shredding direction responsive to the detector detecting both the presence of the at least one article to be shredded being received by the throat and that the thickness thereof is less than the predetermined maximum thickness. 
     
     
       14. A shredder according to  claim 1 , wherein the detector is a thickness detector and the shredder further comprises a presence detector configured to detect a presence of the at least one article to be shredded being received by the throat,
 wherein the controller is configured to operate the motor to drive the cutter elements in the shredding direction responsive to the presence detector detecting the presence of the at least one article to be shredded being received by the throat.   
     
     
       15. A shredder according to  claim 14 , wherein the controller is configured to operate the motor to drive the cutter elements in the shredding direction responsive to both the presence detector detecting the presence of the at least one article to be shredded being received by the throat and the thickness sensor detecting that the thickness thereof is less than the predetermined maximum thickness. 
     
     
       16. A shredder comprising:
 a housing having a throat open to an exterior of the housing for permitting a user to feed at least one article to be shredded;   a shredder mechanism received in the housing and including an electrically powered motor and cutter elements, the shredder mechanism enabling the at least one article fed into the throat to be shredded to be fed into the cutter elements and the motor being operable to drive the cutter elements in a shredding direction so that the cutter elements shred the articles fed therein;   a thickness detector configured to detect a thickness between opposing major surfaces of the at least one article to be shredded being received by the throat;   a maximum thickness indicator having a visual or audible output and configured to indicate a visual or audible signal to a user of the shredder via the visual or audible output;   a controller configured to actuate the maximum thickness indicator and indicate the visual or audible signal to the user via the visual or audible output responsive to the detector detecting that the thickness of the at least one article is at least equal to a predetermined maximum thickness;   wherein the detector is a thickness detector and the shredder further comprises a presence detector configured to detect a presence of the at least one article to be shredded being received by the throat, wherein the controller is configured to operate the motor to drive the cutter elements in the shredding direction responsive to the presence detector detecting the presence of the at least one article to be shredded being received by the throat;   wherein the controller starts the motor to drive the cutter elements in the shredding direction only in response to both the presence detector detecting the presence of the at least one article to be shredded being received by the throat and the thickness detector detecting that the thickness thereof is less than the predetermined maximum thickness.   
     
     
       17. A shredder according to claim 16, wherein the detector comprises a contact member that extends into the throat and is actuated in response to the article being inserted into the throat. 
     
     
       18. A shredder according to claim 17, wherein said thickness detector is a variable thickness detector for outputting a variable amount of movement of said contact member. 
     
     
       19. A shredder according to claim 18, wherein said thickness detector includes an optical sensor and indicators movable past the optical sensor by movement of said contact member to enable the variable amount of movement of said contact member to be output by the optical sensor. 
     
     
       20. A shredder according to claim 18, wherein the detector further comprises a strain gauge configured to measure movement of the contact member and communicate the movement to the controller. 
     
     
       21. A shredder according to claim 18, wherein the detector further comprises a piezoelectric sensor configured to measure movement of the contact member and communicate the movement to the controller. 
     
     
       22. A shredder according to claim 16, wherein said thickness detector includes a sensor and the contact member is coupled to a detectable element movable for detection by the sensor, and wherein said thickness detector is configured such that movement of said contact member in the throat amplifies movement of the detectable element at the sensor.