Not Applicable.
Not Applicable
The present invention relates to the implements, and more particularly to an implement including an engine start interlock.
Implements, such as lawn mowers and snow blowers, are typically powered by a prime mover, such as an internal combustion engine. Many of these implements have an electric start, i.e. the engine is started by an electric starter connected to a battery or other electrical source. Current manufacturers include sensors in an ignition circuit actuating the starter to ensure certain conditions are met prior to starting the engine. For example, sensor switches incorporated in the ignition circuit are often used to determine the position of the controls for the power take off (PTO), ground drive, and parking brake.
The sensors are provided to ensure the PTO is disengaged and the parking brake is engaged when starting the engine. The goal of these and other sensors is to ensure the implement does not surprise the operator with any unexpected actions when the engine is started. Unfortunately, providing multiple sensors that determine the position of various implement controls complicates the ignition circuit rendering the implement unreliable. Therefore a need exists for a simpler and more reliable implement that will not surprise an operator with any unexpected actions.
The present invention provides a simpler and more reliable implement that will not surprise an operator with any unexpected actions by providing an implement that ensures an operator is not inadvertently operating controls while starting the engine. This is accomplished by requiring the operator use two hands to start the engine making it very difficult to engage the PTO or ground drive.
One embodiment of the present invention is an implement including an internal combustion engine. An electric starter is provided to start the internal combustion engine. An ignition circuit actuates the electric starter. A first normally open switch forming part of the ignition circuit is mounted on the implement at a first position and must be held closed by an operator for the ignition circuit to actuate the electric starter. A second normally open switch forming part of the ignition circuit is mounted on the implement at a second position and must be held closed by an operator for the ignition circuit to actuate the electric starter. The first position is spaced from the second position a sufficient distance to prevent an operator from closing both the first normally open switch and the second normally open switch with a single hand.
The advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims herein for interpreting the scope of the invention.
As shown in
Right and left handlebars 22, 24 extending rearwardly from the frame 14 include grips 26, 28 for grasping by the operator to steer the implement 10. Forward and reverse control levers 34, 36 pivotally mounted proximal the grip 26 on the right handlebar 22 selectively engage the engine 12 to propel the implement 10 in the forward and reverse directions. A PTO lever 38 pivotally mounted on the left handlebar 24 selectively engages the blades in the mower deck 20 with the engine 12 to rotate the blades for cutting grass.
A control panel 40 extending between the handlebars 22, 24 supports a key switch 42, an interlock switch 44, and a throttle control 46. The key switch 42 and interlock switch 44 form part of an ignition circuit 48, such as shown in
The ignition circuit 48 includes the key switch 42, interlock switch 44, a starter solenoid 50, and a battery 54 (also shown in
The interlock switch 44 is preferably a normally open momentary rocker switch having an open position and a closed position. The interlock switch 44 is biased away from the closed position and must be held in the closed position by the operator to maintain the switch 44 in the closed position when starting the engine 12. Although a momentary rocker switch is disclosed, any normally open switch biased away from a closed position, such as a keyed switch, push button switch, and the like can be used without departing from the scope of the invention.
The key switch 42 is a normally open standard keyed ignition switch and requires turning a key inserted in a key hole to close the key switch 42. Preferably, the key switch 42 is biased away from the closed position requiring the operator hold the key in a turned position to keep the switch 42 closed when starting the engine 12. Although a key switch 42 is disclosed, any normally open switch biased away from a closed position, such as a momentary rocker switch, push button switch, and the like, can be used without departing from the scope of the invention.
Advantageously, the key switch 42 and interlock switch 44 are mounted on the control panel 40 at positions a sufficient distance from each other to prevent the operator from actuating, i.e. closing, both switches 42, 44 using one hand. As a result, two hands are required to start the engine 12. In particular, one hand must turn the key in the key switch 42 and the other hand must depress the interlock switch 44 to start the engine 12. As a result, the location of both hands of the operator are known at the time the engine 12 is started. Advantageously, by requiring an operator to use both hands to start the engine 12, it is very difficult for the operator to inadvertently have the PTO or ground drive engaged when starting the engine 12.
The location and type of the switches determines whether a distance is sufficient to prevent an operator from closing two normally open, operator actuated switches. For example, between three and five inches is sufficient to prevent an operator from actuating both a key ignition switch and a rocker switch mounted on the face of a control panel. Eight inches, however, are required if both switches are rocker switches. Whereas, two inches is sufficient if both switches are key ignition switches. Likewise, overlapping edges of the switches separated by the thickness of the control panel is sufficient for two rocker switches if one rocker switch is mounted to the face of the control panel and the other rocker switch is mounted on the back of the control panel.
Preferably, as shown in
In use, the operator starts the engine 12 by inserting a key into the key switch 42 with a right hand and depressing the interlock switch 44 with a left to close the interlock switch 44. While depressing the interlock switch 44 with the left hand, the operator turns the key in the key switch 42 to close the key switch 42. Assuming all other contacts, if present, in the ignition circuit 48 are properly closed, the ignition circuit 48 energizes the starter solenoid 50 to actuate the electric starter 52 and start the engine 12. Of course, the locations of the key switch 42 and interlock switch 44 can be different from that shown in the
While there has been shown and described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims.