Patexia Contest


Prior Art Search


This contest is for a prior art search for US Patent No. 10,117,388 which describes a stump grinder having a single two-axis joystick that is used to control the movement of the attached grinding wheel/drum. 

The stump grinding machine includes a frame, an arm, and a grinding wheel or drum that attaches to the arm.  When activated, the grinding wheel or drum spins about an axis horizontal to the ground for grinding (or comminuting) a stump.  A two-axis joystick controls the movement of the grinding wheel/drum.  When the joystick is moved right or left, the grinding wheel/drum moves right or left.  When the joystick is moved backward or forward, the grinding wheel/drum is raised or lowered.  The most preferred reference will also teach a switch or trigger on the joystick that starts or stops the grinding wheel/drum from spinning.  Note: the switch only needs to start or stop the wheel/drum from spinning, not necessarily both. 

Stump Grinder

Acceptable prior art includes traditional stump grinder machines with the necessary control joystick as well as other machines that can, and did, accept a stump grinder attachment (e.g., excavators, mini-excavators, back hoes, crawlers, skid steers, mini-skid steers, etc.).  Please note that acceptable references that rely on other types of machines having the required two-axis joystick must actually teach/show the use of that machine with the stump grinder attachment.  The prior art has already been located that depicts an excavator or mini-excavator with the proper control joystick format (left stick swings boom right and left and raises and lowers the boom) and the necessary switch on that joystick for powering an auxiliary attachment.  See Known References (e.g., Kubota U48-4 which includes a left joystick having the proper control format and also having an auxiliary attachment activator switch mounted on top).  As a further note to researchers:  many excavators and mini-excavators provide the ability for an operator to switch the format of the joystick controls.  Certain of these formats allow the joystick to control the operation of the machine boom in a way that satisfies the requirements of the patent-at-issue.  Care should be taken to verify that a given prior art reference teaches a two-way joystick with control inputs that satisfy the up/down/raise/lower requirements of the ‘388 patent claims. 

To improve on previously identified results, researchers should locate a reference that not only teaches or depicts the use of a machine having the right control joystick—but that also teaches the use of that machine with a stump grinder attachment—before January 10, 2011.  

Submitted documents describing this above stump grinder must be:

  • Filed, published, or disclosing the similar functionality of a stump grinder that was in public use or on sale before January 10, 2011.

  • Not on the known references list (please check very carefully)

  • Non-patent literature will have additional 5 bonus points

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1Is the reference either a U.S. Patent filed, a foreign patent published, or a non-patent document published or otherwise publicly available before January 10, 2011? T/F
2Does the reference show a machine that is capable of grinding a tree stump? 10
3Does the machine have a grinding tool (typically in the shape of a wheel or drum) that rotates about an axis that is parallel to the ground? 10
4Is the grinding tool attached to an arm that is capable of pivoting up and down and side to side, thereby causing the grinding tool to move up and down and side to side? 10
5Does the machine come with a single joystick that can be moved right and left to pivot the arm right and left and that can be moved backward and forward to pivot the arm up and down? 40
6Does the machine have a mechanical or electronic switch mounted on, or integral to, the joystick that, when activated, turns the grinding tool on or off (i.e., making the tool rotate or stop rotating)? This could be a switch, trigger, button, operator presence switch, or a capacitive touch sensor. 30

Additional Notes

Prior Art Search

Prior Art Search

This is a Prior Art Search contest aimed at determining if a patent idea was known and publicly available before a patent was filed.

  • +5 bonus points will be awarded for non-patent literature such as user's manual or peer-reviewed papers
  • +5 bonus points will be awarded for foreign language references.

This contest will close on Sunday, March 7, 2021 at 11:59 PM PT.

Please review the Contest Rules. For more information on how to submit to this Contest type, please read the Intro to Prior Art Search page.