Patents by Inventor Donald L. Hildebrand

Donald L. Hildebrand 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: 4460186
    Abstract: A sweeper, which has a pair of front wheels which are mounted on a frame on opposite sides of a dirt hopper, a steerable guide wheel unit mounted on the frame in a tricycle arrangement with respect to the front wheels characterized by the guide wheel unit having a suspension having first and second members arranged with one member being telescopically received and the other member with an arrangement for transmitting torque between the members and the unit has an arrangement positioned between the two members for resiliently suspending the two members. The arrangement for resiliently suspending can comprise a single coiled spring telescopically receiving an outside member or a plurality of spring units that are provided either by themselves or with shock absorber units. The arrangement for transmitting torque can include a splined shaft and an internally splined bore or a plurality of torque transmitting lever arms.
    Type: Grant
    Filed: February 8, 1982
    Date of Patent: July 17, 1984
    Assignee: Elgin Sweeper Company
    Inventors: Donald L. Hildebrand, Mario J. Martinez
  • Patent number: 4343060
    Abstract: A street sweeper having a frame with a cab carried thereon. An engine is mounted on the frame for powering the sweeper. A series of operating mechanisms are supported on the frame for assisting in a sweepings pick-up operation. A series of hydraulic motors are provided with each being operatively associated with one of the mechanisms for operating the same. A single variable and reversible flow piston pump is operatively connected to the hydraulic motors and the hydraulic mechanisms for operating them at a constant speed. The engine operates the piston pump with a variable speed input. A control mechanism is mounted in the cab, and electrical circuit means is connected between the control mechanism and the piston pump and cooperable with said control mechanism enabling for selective operation of the mechanisms at selective rotational speeds for assisting in a sweepings pick-up operation.
    Type: Grant
    Filed: July 18, 1980
    Date of Patent: August 10, 1982
    Assignee: Elgin Sweeper Company
    Inventors: Donald L. Hildebrand, Ernest F. Prescott
  • Patent number: 4236756
    Abstract: A street sweeper having a frame with a cab positioned at a forward end of the frame. A hopper is provided for receiving sweepings carried on the frame behind the cab. Linkage is further provided for enabling the hopper to be moved over the cab to a forward dumping position. Outriggers are positioned at a forward end of the sweeper. Hydraulic circuit means, valve means, and ram means collectively cooperable together and sequentially operable to initially move the outriggers into ground engagement to provide additional support for the hopper when in the forward dumping position and then operable to actuate the linkage to move the hopper over the cab for dumping.
    Type: Grant
    Filed: December 4, 1978
    Date of Patent: December 2, 1980
    Assignee: Elgin Sweeper Company
    Inventors: Donald L. Hildebrand, Ernest F. Prescott
  • Patent number: 4222141
    Abstract: A self-propelled street sweeper including a main frame, sweepings pick-up means underlying the main frame and a dirt box positioned on the frame for receiving the sweepings. A main broom is mounted at a rear end of the main frame adapted to sweep sweepings to the sweepings pick-up means or conveyor so the sweepings can be deposited into the dirt box and having sweeping and road travel positions. Means is provided for driving the main broom when in its sweepings position. Means is further provided for suspending the main broom from the rear end of the main frame including suspension arms located on opposite sides of the main broom. Bearing means are provided between the suspension arms and the opposite sides of the main broom. Floating suspension means is operatively connected between the main broom and the main frame providing a floating suspension for enabling the main broom to freely float on a ground supporting surface as the main broom is dragged behind the main frame in road engagement.
    Type: Grant
    Filed: May 4, 1979
    Date of Patent: September 16, 1980
    Assignee: Elgin Sweeper Company
    Inventors: Gerald N. Kieft, Donald L. Hildebrand
  • Patent number: 4178647
    Abstract: A street sweeping machine is disclosed comprising a wheeled frame, a cab is supported by the frame, a dirt receiving hopper is positioned behind the cab, a conveyor is positioned adjacent the hopper and has an upper end overlying the hopper for depositing materials picked up from a roadway into the hopper. The conveyor is pivotally mounted for movement relative to the hopper and the frame. Hopper lift means is provided for rotating the hopper off of the frame from behind the cab over the cab for unloading of the picked-up materials in the hopper at a forward end of the cab. Linkage is connected between the hopper lift means and the conveyor for pivoting the conveyor on its pivot so that its upper end moves clear from its position of overlying the hopper to allow the hopper lift means to rotate the hopper free of interference from the conveyor during the lifting movement of the hopper. Ram means is also provided for operating the hopper lift means to rotate the hopper to be unloaded forward of the cab.
    Type: Grant
    Filed: September 8, 1978
    Date of Patent: December 18, 1979
    Assignee: Elgin Sweeper Company
    Inventors: John J. Wolynec, Donald L. Hildebrand, Victor Wasynczuk
  • Patent number: 4171551
    Abstract: A self-propelled street sweeping machine or sweeper which includes a main frame. A dirt hopper and a main broom are mounted on the frame along with a conveyor. The conveyor is positionable relative to the frame for receiving sweepings from the main broom and for discharging the sweepings into the dirt hopper. Means are provided on the sweeper for enabling the main broom and the conveyor to move selectively of a transport position to a sweeping position and vice versa. The frame is supported by front and rear axles carried on wheels and spring means are provided between the rear axle and the main frame to enable an easier ride while the sweeper is operated in the transport position.
    Type: Grant
    Filed: September 8, 1978
    Date of Patent: October 23, 1979
    Assignee: Elgin Sweeper Company
    Inventors: Donald L. Hildebrand, Jack Mitchell, Gerald N. Kieft, Ernest F. Prescott