Patents by Inventor Donald D. Gronholz

Donald D. Gronholz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4657570
    Abstract: The present invention is directed to a device (50) for providing filtration of air. The device includes a body (70) and a cover (72) with each having endless mating structure (76) and (78) which may be welded together thereby mechanically pinching a flat sheet filter media (74) and holding it in place. The cut edge of the filter media (74) is encapsulated. The filter media (74) is held outwardly from bottom (92) of body (70) by gussets (90) to provide sufficient area for air to pass through. Inlet openings (110) are provided between top (94) and endless mating structure (78) in a fashion which allows top (94) to be attached to a flat wall of a sealed housing of a type used for disk drive systems.
    Type: Grant
    Filed: March 20, 1985
    Date of Patent: April 14, 1987
    Assignee: Donaldson Company, Inc.
    Inventors: Donald D. Gronholz, Kirk A. Schneider, James R. Scott
  • Patent number: 4617122
    Abstract: A crimp seal pleated filter assembly having a base (20), a frame (40) and a filter media (60), including a plurality of pleats (66). When assembled, the pleats (66) of the filter media (60) are uniformly aligned within the assembly 10 and are secured therein by crimp sealing the filter media ends (62) between interlocking projections (30) 50 on the sides (23) of the base (20) and side walls 43 of the frame. Outboard end flaps (68) of the filter are crimp sealed and encapsulated between side blades (26) of the frame (20) and the front wall (42) and back wall (44) of the frame, minimizing flaking or chafing of fibers from the filter (60).
    Type: Grant
    Filed: August 1, 1984
    Date of Patent: October 14, 1986
    Assignee: Donaldson Company, Inc.
    Inventors: Barbara L. Kruse, Darrell D. Gronli, Donald D. Gronholz
  • Patent number: 4512891
    Abstract: A filter assembly (10) includes a frame (10 and 12) and means (10, 32, 34, 36, 38, 44, 48, and 50) releasably retaining a replaceable pleated filter element (14) therein. The edges of the pleats (68) of the filter element (14) are folded over diagonal fold lines (70) and tucked between adjacent pleats in a manner which provides control expansibility and substantially even pleat spacing upon expansion after storage in collapsed condition.
    Type: Grant
    Filed: November 16, 1982
    Date of Patent: April 23, 1985
    Assignee: Donaldson Company, Inc.
    Inventors: Mervin E. Wright, Donald D. Gronholz
  • Patent number: 4044805
    Abstract: An improved arrangement by which a router may be accurately and inexpensively used to trim the edge of a laminate overlay flush with the edge of the underlying wooden member. It particularly comprises a guide fence having a relatively long straight edge interrupted centrally by a recess for the router bit, and provided with a rabbet into which the projecting edge of a rough trimmed laminate may project early in the edging process. The fence cooperates with a sub-base attachable to a router, and retains the versatility of the router for many usual applications.
    Type: Grant
    Filed: February 4, 1976
    Date of Patent: August 30, 1977
    Inventor: Donald D. Gronholz
  • Patent number: RE33045
    Abstract: An improved arrangement by which a router may be accurately and inexpensively used to trim the edge of a laminate overlay flush with the edge of the underlying wooden member. It particularly comprises a guide fence having a relatively long straight edge interrupted centrally by a recess for the router bit, and provided with a rabbet into which the projecting edge of a rough trimmed laminate may project early in the edging process. The fence cooperates with a sub-base attachable to a router, and retains the versatility of the router for many usual applications.
    Type: Grant
    Filed: November 6, 1987
    Date of Patent: September 5, 1989
    Inventors: Donald D. Gronholz, deceased, by Marlene J. Gronholz, administrator