David R Berg
General Contractor in Minneapolis, MN

6117200, Sep 12, 2000

Jul 9, 1998

9/112393

David W. Berg - Plymouth MN
Bruce F. Field - Golden Valley MN
Joseph L. Pouliot - Elk River MN

Tennant Company - Minneapolis MN

A47L 920, B01D 4604

55287

A mobile surface maintenance machine has a cleaning brush and a dust collection system mounted on the machine. The dust collection system includes a vacuum fan, a filter housing having an air inlet and a pleated filter element positioned within the housing with its upstream side being in communication with the housing air inlet. The filter housing has separate, side-by-side, chambers on the downstream side of the filter. There are electrically operated valves located in the filter housing on the downstream side of the filter element, with the valves being in communication with the vacuum fan. There is one valve controlling air flow from each chamber. The filter element is functionally divided into separate, but joined, pleated sections, with each section being aligned with one of the chambers. There is an electric actuator mounted on the downstream side of each pleated filter section and there is a pleat moving element associated with and movable by each electric actuator. The pleat moving elements each are in engagement with only the pleats in one filter section.

6096383, Aug 1, 2000

Apr 28, 1999

9/300921

David W. Berg - Plymouth MN
Bruce F. Field - Golden Valley MN
Norman William Gill - Plymouth MN
Joseph S. Keute - Blaine MN
Deone E. Johnson - Edina MN
Earl Oscar Frederick Krueger - Eagan MN

Tennant Company - Minneapolis MN

C08F 248, C08F 244, B32B 3128, B32B 3500

427493

A process for applying a coating to a floor surface and curing that coating after application includes the steps of first spreading a photochemically curable liquid coating in a thickness of from about 0. 003 to about 0. 006 inches on a floor surface. After the coating has been applied, it is exposed to ultraviolet radiation at a power level of about 40 watts per inch of width of coating being cured and at two different sequentially applied wavelengths. This cures the liquid coating instantly to a durable solid coating. The first applied ultraviolet radiation may have the wavelength of about 365 nm and the second applied ultraviolet radiation may have a wavelength of about 254 nm. The ultraviolet radiation is provided by an array of UV lights on a mobile, self-powered vehicle which moves over the floor coating at a speed in the range of 20 to 40 feet per minute.

5884353, Mar 23, 1999

Dec 1, 1997

8/980798

David W. Berg - Plymouth MN
Michael S. Wilmo - Crystal MN

Tennant Company - Minneapolis MN

A47L 1118

15 83

A surface maintenance machine includes a body, wheels for supporting the body, a sweeping brush and a debris hopper adjacent the sweeping brush and positioned to receive debris swept by the brush. The hopper has a floor, walls, and a top, all formed of a plastic material, preferably one rated as not supporting combustion in a horizontal direction. There is a heat shield attached to the underside of the hopper top, with the heat shield being formed of a non-combustible material.

5088149, Feb 18, 1992

Aug 6, 1990

7/562800

David W. Berg - Plymouth MN
David J. Brenner - Eden Prairie MN
Ronald W. Lehman - Brooklyn Park MN
Bruce W. Forsman - Plymouth MN

Tennant Company - Minneapolis MN

A47L 700

15322

An improved scrub head for a cleaning wand to be used with a floor cleaning machine. The scrub head is supplied with vacuumized air and pressurized cleaning solution through the wand from the machine. The scrub head has a nozzle for applying cleaning solution to the floor, a powered rotating tool such as a brush or a pad for scrubbing the floor, and a vacuum pickup shoe or squeegee for picking up soiled cleaning solution. The squeegee, when used, has flexible lips of a novel and improved design. The rotating tool is driven by an air turbine which takes in its air from essentially clean ambient atmosphere, and a valve selectively and automatically connects the vacuumized air to either the turbine outlet, thus causing the turbine and tool to rotate for scrubbing the floor, or to the pickup shoe or squeegee for picking up soiled cleaning solution and debris.

D273620, Apr 24, 1984

Aug 30, 1982

6/412876

Paul W. Kimzey - Minneapolis MN
David W. Berg - Plymouth MN
Warren L. Larson - Brooklyn Park MN

Tennant Company - Minneapolis MN

D32 16