Speed control assembly for a self-propelled walk behind lawn mower
AssigneeMTD Products Inc
InventorsPhilip Helin, Rick Baehr
Life of this patent
Estimating the term…
Abstract
A speed control mechanism for controlling selective engagement of the self-propelled transmission assembly for a walk-behind lawn mower is provided. The speed control mechanism is also configured to control the relative output speed of the transmission assembly. The speed control mechanism includes a speed engagement assembly and a speed adjustment assembly, wherein the speed engagement assembly includes a pair of rotatable levers for causing the transmission assembly to actuate between a disengaged position and an engaged position and the speed adjustment assembly includes a rotatable knob for causing the relative output speed of the transmission assembly to the wheels of the lawn mower to increase or decrease.
Claims18
A transmission assembly for a self-propelled walk-behind lawn mower, said transmission assembly comprising:
- a housing;
- a first actuator attached to said housing;
- a second actuator attached to said housing;
- a first pulley rotatably driven by a belt extending between said first pulley and an engine, said first pulley is connected to said housing, said first pulley having an upper pulley member, a lower pulley member, and an effective diameter directly relating to a distance said upper pulley member is spaced apart from said lower pulley member, wherein said second actuator is configured to selectively move one of said upper or lower pulley members relative to the other of said upper or lower pulley members;
- and
- a drive shaft partially disposed within said housing, said drive shaft being operatively coupled to said first pulley, wherein rotation of said first pulley is transferred into rotation of said drive shaft to produce a rotational output of said drive shaft to drive a pair of ground-engaging wheels when said housing is in an engaged position,
- wherein translation of one of said pulley members relative to the other of said pulley members changes said distance between said upper and lower pulley members, wherein said change in said distance changes said effective diameter of said first pulley which results in a change of speed of said rotational output of said drive shaft, and
- wherein said first actuator is configured to move said housing selectively between an engaged position and a disengaged position, and said second actuator is configured to operate independently of said first actuator.
A transmission assembly for a self-propelled walk-behind lawn mower, said transmission assembly comprising:
- a housing;
- a first pulley rotatably driven by a belt extending between said first pulley and an engine, said first pulley is connected to said housing, said first pulley having an upper pulley member, a lower pulley member, and an effective diameter, wherein said effective diameter directly relates to a distance said upper pulley member is spaced apart from said lower pulley member, wherein said lower pulley member is translatable relative to said upper pulley member;
- a drive shaft partially disposed within said housing, said drive shaft being operatively coupled to said first pulley wherein rotation of said first pulley is transferred into rotation of said drive shaft to produce a rotational output of said drive shaft to drive a pair of ground-engaging wheels when said housing is in an engaged position, wherein a change in said effective diameter results in a change of speed of said rotational output of said drive shaft;
- wherein movement of said housing selectively actuates said housing between said engaged position and a disengaged position;
- and
- a speed control assembly, said speed control assembly comprising:
- a casing;
- a knob rotatably connected to said casing, wherein said knob is rotatable between a plurality of operative positions which causes translation of said lower pulley member relative to said upper pulley members for changing said distance therebetween;
- and
- an indexer positioned within said casing, said indexer being operatively connected to said knob, wherein rotation of said knob causes translational movement of said indexer,
- wherein each of the plurality of operative positions produces a different relative speed of rotational output of said drive shaft,
- wherein said knob is operatively connected to said lower pulley member,
- wherein rotation of said knob translates said lower pulley member relative to said upper pulley member to change said effective diameter of said first pulley
- wherein movement of said housing and translation of said lower pulley member can occur independently.
Dependencies are inferred from the claim text.