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US 4,900,881 AGranted
Safety interlock for floor maintenance machine and method
AssigneeBreuer Electric Mfg. Co.
InventorErnest J. Fischer
Life of this patent
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AssigneeBreuer Electric Mfg. Co.
InventorErnest J. Fischer
Estimating the term…
A floor maintenance machine has a base, an electric motor on the base for moving a floor treating element and a handle connected to the base. Carried by the handle are an electric switch for connecting electric power to the motor, a pair of manually movable hand levers for controlling actuation of the switch, and a safety latch and an interlock mechanism for preventing and enabling movement of the hand levers to actuate the switch. The safety latch normally blocks movement of the hand levers from off to on positions to actuate the switch, but may be manually moved to a release position out of blocking relationship with the hand levers. When the safety latch is in its release position, movement of the hand levers from their off to their on positions is then controlled by the interlock mechanism, which enables both hand levers to be simultaneously moved from their off to their on positions to actuate the switch and energize the motor, but prevents only one hand lever from being moved from its off to its on position while the other hand lever is in its off position. Once both hand levers have been simultaneously moved to their on positions, only one hand lever then needs to be held in its on position to continue to energize the motor. By virtue of the interlock mechanism, both hands of an operator must be on the machine to start it.
A method of controlling start up of an electrically powered floor maintenance machine having an electric motor for moving a floor treating element and a pair of hand levers that are squeezable by an operator, comprising the steps, each beginning with neither hand lever being squeezed, of causing energization of the electric motor upon both hand levers being simultaneously squeezed;
A method of controlling start up of an electrically powered floor maintenance machine having an electric motor for moving a floor treating element and a pair of hand levers that are movable between deactuated and actuated positions to control energization of the electric motor, comprising the steps of enabling both hand levers to be simultaneously moved from their deactuated to their actuated positions;
A method of controlling start up of an electrically powered floor maintenance machine having an electric motor for moving a floor treating element and a pair of hand levers that are movable between deactuated and actuated positions to control energization of the electric motor, such that when either hand lever is moved to its actuated position the electric motor is energized, said method comprising the steps of enabling the pair of hand levers to be simultaneously moved from their deactuated to their actuated positions;
In a floor maintenance machine, an electric motor for moving a floor treating element;
In a floor maintenance machine, an electric motor for moving a floor treating element;
A floor maintenance machine comprising a base;
Dependencies are inferred from the claim text.