Tennant Company

Donald J Haub

Keith N Krier

Alfred D Carlson

Raymond C Hawkins

Howard N Seim

Mark E Snetting

Steven J Waldhauser

Neil F Brown

Neil T Brown

In a combination sweeping, polishing and scrubbing floor maintenance machine, the present invention includes a debris hopper removably positioned in a frame secured to a portion of the machine. The debris hopper has a rearward opening facing a pair of substantially side-by-side disc tools, e.g. brushes. The brushes preferably rotate in the same rotational direction with one brush positioned slightly ahead of the other brush. Immediately in front of the forward edge of the leading brush is a conduit means secured to the hopper. Adjacent the conduit means and extending along the hopper opening is a flexible member. Both the flexible member and the conduit means serve as debris receiving means for directing swept debris upwardly into the debris hopper. Blade members may be provided forward of the debris receiving means and beneath the hopper to guide debris into a central area of the machine's path of travel.

Debris collecting mechanism

Combination sweeper-scrubber floor machine

An improvement for electrically driven floor maintenance apparatus including means for varying the speed of the driving motors is disclosed. Two speed ranges are provided by switching means which change the interconnection of the drive motors from series for the low speed range, and parallel for the high speed range. Within each speed range, intermediate speeds are provided by placing resistors with shunt in series with the motors. Time delay circuitry is also included to prevent immediate operation of the vehicle in the high speed of each range until the vehicle has had some time to accelerate. Additionally, means are provided for detecting whether a vehicle is rolling in a forward or reverse direction and circuits are provided to prevent the operator from driving the vehicle in an opposite direction until the vehicle has slowed down to a near stop. A deadman control is provided to prevent the energizing of the drive motors when the operator is no longer seated on the driver's seat. ///

Multi-speed drive with forward/reverse lockout

A reversible electrically driven motor is disclosed together with circuitry for controlling the direction of the motor such that the current to the drive motor cannot be reversed to an opposite direction while the motor continues operation in a first direction. Once the motor slows to predetermined speed, which may approximate near-stop condition, the circuitry permits the voltage to operate in the opposite direction thereby reversing the motor. The control apparatus may include the portion of the electric motor which operates as a generator when the motor is not being electrically driven, a solid state sensor for sensing the voltage generated, and a lock-out circuit which responds to the sensed voltage to disable the operation of the driving circuit which reverses the motor.

Control circuit for reversible electric motors

An improvement for floor maintenance equipment employing electrically driven scrubbing or polishing brushes including means for varying the speed of the brush motors. Two brush speeds are provided by switching apparatus which change the interconnection of the brush motors from series to parallel and from parallel to series. This results in a substantial change in motor speed and power.

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Champlin, MN, United States of America

Donald J Haub