Battery-powered lawn cutting system

A control system for a battery-powered lawnmower comprising:

• a lawnmower handle having a first end interconnected with a chassis of said lawnmower, and having an opposed second handle end disposed away from said chassis;
• a deadman control interconnected with said second end of said handle, said deadman control including a movable member that is held by an operator during operation of said lawnmower, and that is released by said operator to stop said lawnmower;
• means for stopping said lawnmower upon the occurrence of at least one predetermined condition;
• and
• means for restarting said lawnmower after said lawnmower has been stopped by said stopping means, by releasing said movable member and by thereafter moving said movable member.

A safety device for a battery-powered lawnmower, said lawnmower having a chassis, said safety device comprising:

• a removable battery, including
• a surface disposed near an upper end of said battery;
• at least one electrical connector interconnected with said chassis;
• a removable key, including
• at least one electrically conductive member that engages said electrical connector to allow said lawnmower to operate;
• and
• an engagement member that causes said battery and said key to engage each other, whereby the removal of said battery also disengages said electrically conductive member from said electrical connector.

A safety device for a battery-powered lawnmower, said lawnmower having a chassis, said safety device comprising:

• a removable battery;
• at least one electrical connector interconnected with said chassis;
• a removable key, including
• at least one electrically conductive member that engages said electrical connector to allow said lawnmower to operate;
• and
• an alarm circuit that provides an alarm when the electrically conductive member of said key engages said electrical connector.

A handle attachment assembly for a lawnmower, comprising:

• two channels disposed on opposite sides of a mower housing of said lawnmower, each of said channels including:
• a first sidewall;
• a second sidewall that is non-parallel to said first sidewall;
• a lawnmower handle member having two ends, each end being received in one of said channels, wherein the shape of an outer surface of the handle member end corresponds to the shape of the channel into which the handle member is received;
• and
• means for attaching each of said handle members to said housing.

A cutting blade for a lawnmower, said cutting blade having a longitudinal axis, comprising:

• a lead cutting edge disposed near one end of said blade;
• a trailing lift edge disposed opposite to at least a portion of said cutting edge;
• and
• an outer blade edge at the end of said blade between said cutting edge and said lift edge;
• wherein a portion of the outer blade edge between the cutting edge and the blade longitudinal axis forms an included angle with said longitudinal axis taken across said blade that is greater than 90.degree., and wherein said outer blade edge is non-linear.

Apparatus for mounting a removable battery to a lawnmower, comprising:

• a removable battery having at least one projection extending from a side surface of said battery;
• at least one groove formed in said lawnmower and having a longitudinal axis that receives said projection, said groove including
• a first tapered section having a first set of sidewalls, at least one of said sidewalls forming a non-parallel first angle with said longitudinal axis;
• and
• a second tapered section adjacent to said first tapered section having a second set of sidewalls, at least one of said second sidewalls forming a non-parallel second angle with said longitudinal axis.

A safety interlock for a lawnmower, said lawnmower having a chassis that includes a sidewall, comprising:

• a magnetically-responsive switch disposed on said chassis on a first side of said sidewall;
• and
• a removable attachment, including
• means for connecting said attachment to said chassis;
• and
• a magnet disposed on said attachment and on an opposite second side of said chassis sidewall;
• whereby said magnetically-responsive switch is engaged in response to said magnet when said attachment is connected to said chassis.

A battery-powered lawnmower having a chassis, comprising:

• a height adjustment apparatus that adjusts the height of said lawnmower chassis, including:
• a first wheel axle having first and second ends;
• a first pivot arm, interconnected with said first end of said first axle, and having a first pivot interconnected with said chassis;
• a second pivot arm, interconnected with said second end of said first axle, having a second pivot interconnected with said chassis;
• a second wheel axle having first and second ends;
• a third pivot arm, interconnected with said first end of said second axle, having a third pivot interconnected with said chassis;
• a fourth pivot arm, interconnected with said second end of said second axle, having a fourth pivot interconnected with said chassis;
• means for pivoting said first pivot arm about its first pivot;
• link means for pivoting said third pivot arm about its third pivot in response to the pivoting of said first pivot arm;
• whereby the pivoting of said first pivot arm by said pivoting means rotates said first wheel axle to thereby pivot said second pivot arm about said second pivot;
• whereby the pivoting of said first pivot arm by said pivoting means causes said link means to pivot said third pivot arm about its third pivot;
• whereby the pivoting of said third pivot arm by said link means rotates said second wheel axle to pivot said fourth pivot arm about said fourth pivot, thereby adjusting the height of said lawnmower chassis;
• a control system, including:
• a lawnmower handle having a first end interconnected with said lawnmower chassis, and having an opposed second handle end disposed away from said chassis;
• a deadman control interconnected with said second end of said handle, said deadman control including a movable member that is held by an operator during operation of said lawnmower, and that is released by said operator to stop said lawnmower;
• means for stopping said lawnmower upon the occurrence of at least one predetermined condition;
• means for restarting said lawnmower after said lawnmower has been stopped by said stopping means, by releasing said movable member and by thereafter moving said movable member;
• a safety device, including:
• a removable battery;
• at least one electrical connector interconnected with said chassis;
• a removable key, including
• at least one electrically conductive member that engages said electrical connector to allow said lawnmower to operate;
• an engagement member that causes said battery and said key to engage each other, whereby the removal of said battery also disengages said electrically conductive member from said electrical conductor;
• a handle attachment assembly, including:
• at least one channel affixed to said lawnmower chassis, including:
• a first sidewall;
• a second sidewall that is non-parallel to said first sidewall;
• said first end of said lawnmower handle being received in said channel, wherein the shape of an outer surface of said handle first end corresponds to the shape of said channel;
• and
• means for attaching said handle first end to said chassis;
• a cutting blade having a longitudinal axis, comprising:
• a lead cutting edge disposed near an end of said blade;
• a trailing lift edge disposed opposite to at least a portion of said cutting edge;
• an outer blade edge at the end of said blade between said cutting edge and said lift edge;
• wherein a portion of the outer blade edge between the cutting edge and the blade longitudinal axis forms an included angle with said longitudinal axis taken across said blade that is greater than 90.degree., and wherein said outer blade edge is non-linear;
• apparatus for mounting said removable battery, comprising:
• at least one projection extending from a side surface of said battery;
• at least one groove formed in said lawnmower chassis and having a longitudinal axis that receives said projection, said groove including
• a first tapered section having a first set of sidewalls, at least one of said sidewalls forming a first angle with said longitudinal axis;
• and
• a second tapered section adjacent to said first tapered section having a second set of sidewalls, at least one of said second sidewalls forming a second angle with said longitudinal axis.

A control system for a battery-powered lawnmower, comprising:

• a lawnmower handle having a first end interconnected with a chassis of said lawnmower, and having an opposed second handle end disposed away from said chassis;
• a deadman control interconnected with said second end of said handle, said deadman control including a movable member that is held by an operator during operation of said lawnmower, and that is released by said operator to stop said lawnmower;
• means for stopping said lawnmower upon the occurrence of at least one predetermined condition;
• means for momentarily disabling said stopping means for a preset time after the occurrence of said predetermined condition;
• and
• means for restarting said lawnmower after said lawnmower has been stopped by said stopping means, by releasing said movable member and by thereafter moving said movable member.

A control system for a battery-powered lawnmower, comprising:

• a lawnmower handle having a first end interconnected with a chassis of said lawnmower, and having an opposed second handle end disposed away from said chassis;
• a deadman control interconnected with said second end of said handle, said deadman control including a movable member that is held by an operator during operation of said lawnmower, and that is released by said operator to stop said lawnmower;
• means for stopping said lawnmower upon the occurrence of at least one predetermined condition, said at least one predetermined condition including
• a first overcurrent condition wherein the current in said lawnmower exceeds a first level;
• a second overcurrent condition wherein the current in said lawnmower exceeds a second level that is greater than said first level;
• and
• means for restarting said lawnmower after said lawnmower has been stopped by said stopping means, by releasing said movable member and by thereafter moving said movable member.

A safety device for a battery-powered lawnmower, said lawnmower having a chassis and a motor, said safety device comprising:

• a removable battery;
• an electrical circuit that provides power from said battery to said motor;
• and
• a removable key that permits power to be supplied from said battery to said motor, said key also engaging said battery such that removal of said battery also causes the removal of said key and said battery cannot be removed without removing said key, and such that said key may be removed without removing said battery.