This invention relates generally to fill indicators for containers used to collect grass clippings, and more specifically to collection container fill indicators that shut off the cutting blades when the container is full.
Grass mowing machines may include devices that indicate and visually display the full condition of a grass collection container. A common device for determining if a collection container is full is a micro switch. As the container fills, grass clippings build up and eventually contacts a micro switch. The switch may trigger an audible tone or light, or both, to alert the operator. For example, U.S. Pat. No. 5,388,394 relates to a device that informs the operator when the bag is full.
However, such fill indicators may be inconsistent, and there is a risk that the container may become overfilled and the collection system may become plugged. The micro switch may become clogged with grass and stop functioning. The switch may not be activated by light material, such as dry leaves, that does not push hard enough on the switch. Other systems that measure air flow or use electric eyes or windows to determine fullness of a collection container may be unreliable or cost prohibitive.
U.S. Pat. No. 6,622,465 relates to an apparatus and method for a material collection fill indicator that uses a pressure gauge and an auxiliary blower fan to propel clippings through a discharge chute. The pressure gauge senses air pressure in the discharge chute and provides a visible indicator of the level of air pressure. The pressure level in the discharge chute increases as the grass clipping collection container becomes increasingly full. Once the screens in the collection container are covered, static pressure increases rapidly, and the gauge indicates that pressure exceeds a specified value.
Although the fill indicator of U.S. Pat. No. 6,622,465 provides a reliable, useful and economic device to warn an operator before the grass collection container becomes overfilled, there remains a concern that an operator will continue mowing after filling the container. For example, the operator may not see or hear the fill warning, or may continue mowing for a short time and overfill the collection container. If the operator keeps mowing after the container is full, the grass discharge chute and mower deck may get clogged with clippings. The unit then must be cleaned out by disassembling the chute and removing grass clippings by hand. Additionally, grass clippings may accumulate under the mower deck, resulting in poor cut quality.
An apparatus is needed that will prevent continued mowing after the grass collection container is full. An apparatus is needed that will not allow the discharge chute and mower deck to become clogged with clippings. An apparatus is needed that will not allow the container to become overfilled.
A collection container fill indicator is connected electrically to a PTO shutoff to prevent continued mowing after the container is full. The fill indicator may be a pressure sensor having a tube that senses air pressure in the mower collection system which may extend between the discharge opening of a mower deck and a grass collection container. The collection system may include a blower housing, discharge chute, and collection container. A circuit shuts off the PTO and cutting blades when the pressure exceeds a specified value, indicating the collection container is full. The present invention prevents an operator from mowing after the container is full, and prevents continued mowing unless the container is emptied. The present invention provides an effective apparatus for assuring that the discharge chute and mower deck will not get clogged with clippings. Cut quality may be improved because grass clippings cannot accumulate after the discharge chute is full.
In one embodiment shown in
In one embodiment, as shown in
In one embodiment, fill indicator 16 may be of the type that provides an electrical signal sufficient to activate relay 31 to shut off power take off (PTO) clutch 32 and stop rotation of one or more cutting blades. If fill indicator 16 detects a container full condition, which corresponds to a preset value, rotation of the cutting blades may be stopped.
In one embodiment, in which fill indicator 16 is a pressure sensor, a small piston or diaphragm may be positioned inside the housing of the pressure sensor. Air pressure in air line or tube 18 pushes against the piston or diaphragm. When the piston or diaphragm is moved far enough, it closes an electrical contact. This set point, where the contact is closed, may be adjustable, but is preferred to be at about 3½ inches of water column pressure. Optionally, fill indicator 16 may include an adjustment mechanism so that it may close the contact when the level of the collection container is higher or lower.
In one embodiment, as shown in
In one embodiment, the fill indicator may be a pressure switch that closes a circuit if air pressure in the collection system reaches a specified value indicating that grass collection container 14 is full. When the fill indicator or pressure switch closes, the circuit between lines 32 and 33 is closed. Coil 34 may cause contact 35 to move between pin 1 and pin 4, while feedback loop 39 connects pin 2 to pin 4. Feedback loop 39 may cause the relay to latch and remain active until power is removed, preventing the power take off (PTO) and cutting blades from being reactivated until the relay is reset and unlatched by removing power.
In one embodiment, warning indicator 36 also may be electrically connected to the circuit and may be activated when pressure switch 16 is closed due to a full collection container. The warning indicator may be a light or an alarm, either of which may be connected through lines 37 and 38 to relay 31.
In one embodiment, activation of relay 31 may disconnect PTO clutch 32. If power is removed from coil 34, contact 35 reconnects pin 1 to pin 3, and the relay may return to its unpowered state. The PTO clutch may remain in this state until power is removed and another PTO clutch command is received.
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
The entire right, title and interest in and to this application and all subject matter disclosed and/or claimed therein, including any and all divisions, continuations, reissues, etc., thereof are, effective as of the date of execution of this application, assigned, transferred, sold and set over by the applicant(s) named herein to Deere & Company, a Delaware corporation having offices at Moline, Ill. 61265, U.S.A., together with all rights to file, and to claim priorities in connection with, corresponding patent applications in any and all foreign countries in the name of Deere & Company or otherwise.