David K Berg

US Patent:

47291419, Mar 8, 1988

Filed:

Jan 7, 1987

Appl. No.:

7/002288

Inventors:

David W. Berg - Plymouth MN
Steven V. Feeny - Plymouth MN

Assignee:

Tennant Company - Minneapolis MN

International Classification:

A47L 11162

US Classification:

15 49R

Abstract:

This is concerned with a disc brush suspension or arrangement for a scrubber or sweeper or the like. The arrangement uses a flexible bellows which may be of rubber or a suitable rubber substitute which functions as the total or primary suspension for the disc brush and its drive motor.

US Patent:

60963832, Aug 1, 2000

Filed:

Apr 28, 1999

Appl. No.:

9/300921

Inventors:

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

Assignee:

Tennant Company - Minneapolis MN

International Classification:

C08F 248
C08F 244
B32B 3128
B32B 3500

US Classification:

427493

Abstract:

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.

US Patent:

59409290, Aug 24, 1999

Filed:

Jun 23, 1997

Appl. No.:

8/880225

Inventors:

David W. Berg - Plymouth MN

Assignee:

Tennant Company - Minneapolis MN

International Classification:

A47L 11204

US Classification:

15334

Abstract:

A surface maintenance machine for use in sweeping and collecting dust and debris from inside and outside areas has a frame and wheels for supporting the frame for movement along the surface to be cleaned. There is a debris hopper on the frame and a rotary sweeping brush on the frame mounted to direct dust and debris from sweeping a surface into the hopper. A vacuum fan is located on the frame and there is an air flow path on the frame from the hopper to the vacuum fan. A dust collection container in the form of a flexible bag is positioned within a vacuum chamber in said air flow path and is in a generally upright disposition. The dust collection container has an air flow entrance adjacent the upper end thereof. During operation of the sweeping brush, dust and debris are directed into the hopper, with the vacuum fan moving dust from the hopper along the air flow path to the dust collection upper air inlet with the debris remaining in the hopper.

US Patent:

61172006, Sep 12, 2000

Filed:

Jul 9, 1998

Appl. No.:

9/112393

Inventors:

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

Assignee:

Tennant Company - Minneapolis MN

International Classification:

A47L 920
B01D 4604

US Classification:

55287

Abstract:

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.

US Patent:

41218400, Oct 24, 1978

Filed:

Nov 4, 1977

Appl. No.:

5/848466

Inventors:

David W. Berg - Wayzata MN

Assignee:

Tol-O-Matic Inc. - Minneapolis MN

International Classification:

F01B 900
F16J 1518

US Classification:

277 4

Abstract:

A seal assembly for use in a cable cylinder to form an effective seal about a generally cylindrical cable section. The seal assembly includes primary and secondary seal members disposed on opposite sides of an alignment sleeve and a retainer sleeve, all of which are disposed within the central bore of a gland member. The central bore includes a plurality of cylindrical bore portions and means cooperating with the retainer sleeve for retaining the seal members and alignment sleeve within the gland for easy insertion and removal thereof.

US Patent:

60706791, Jun 6, 2000

Filed:

Jul 10, 1997

Appl. No.:

8/891003

Inventors:

David W. Berg - Plymouth MN
Joseph D. Berg - Little Falls MN
Dennis R. Johnson - Maple Grove MN

Assignee:

Lindbergh Manufacturing, Inc. - Little Falls MN

International Classification:

B62D 5104

US Classification:

180 192

Abstract:

The present inventive device generally allows a user to easily engage and push or pull heavy and unwieldy object(s), most notably a line of nested shopping carts, effectively and without undue strain. The cart is designed specifically with universal utility in mind. The power is supplied by either an electrically driven motor or internal combustion engine. Power is transmitted to a transaxle with belts or an electric motor electronically controlled. A simple forward/reverse control via throttle handles causes cart movement and steering is achieved through dual rear castors. The front of the cart contains a receiver that allows easy attachment for a multitude of attachments for a variety of uses. A square tube fitment with a quick release device lets the cart be configured for different markets and easy field change. One such attachment is a shopping cart adapter, which attaches to the cart through the receiver connection.

US Patent:

50881493, Feb 18, 1992

Filed:

Aug 6, 1990

Appl. No.:

7/562800

Inventors:

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

Assignee:

Tennant Company - Minneapolis MN

International Classification:

A47L 700

US Classification:

15322

Abstract:

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.

US Patent:

D2736209, Apr 24, 1984

Filed:

Aug 30, 1982

Appl. No.:

6/412876

Inventors:

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

Assignee:

Tennant Company - Minneapolis MN

US Classification:

D32 16