Patents by Inventor Robert C. Berfield

Robert C. Berfield 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: 6073301
    Abstract: A vacuum cleaner includes a backpack enclosure that removably encloses an impeller/motor unit. The backpack enclosure has a substantially block-shaped outer configuration and is made from a pliable cloth material, preferably composed of woven NYLON fibers. Two shoulder straps are attached to the backpack enclosure for carrying the vacuum cleaner. In accordance with an alternative embodiment of the invention, a vacuum cleaner includes a fanny pack enclosure that removably encloses an impeller/motor unit. The fanny pack enclosure is made from a pliable cloth material, preferably composed of woven NYLON fibers. A harness in the form of a waist strap is attached to the fanny pack enclosure for carrying the vacuum cleaner on the waist of a user.
    Type: Grant
    Filed: January 22, 1998
    Date of Patent: June 13, 2000
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 6037685
    Abstract: A thermal protection mechanism for electric motors is disclosed. A brush is urged into electrical contact with a commutator by a primary brush spring. A thermally deformable fastener releasably secures the primary brush spring to a brush housing. A secondary brush spring urges the brush away from the commutator with a force less than that of the primary spring. A thermal overload condition within the motor causes the thermally deformable fastener to substantially deform so that the force exerted on the brush by the primary spring is substantially reduced. The force exerted by the secondary spring overcomes the primary spring so that the brush is forcefully disengaged from electrical contact with the commutator, thereby terminating operation of the motor.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: March 14, 2000
    Assignee: Shop-Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 6009596
    Abstract: A vacuum cleaner has an electric motor driving an air impeller for creating suction and a pump which draws liquid material through an inlet tube from the bottom of a tank and expels it from the tank. The vacuum cleaner also includes a mechanical shut-off and override assembly that automatically shuts off the motor if the liquid level in the tank gets too high. The user, however, can mechanically override this automatic shut-off in order to continue pumping liquid out of the tank. A priming apparatus is disposed in the tank in fluid communication with the pump, and a valve is selectively actuable to establish a pressure differential across liquid in the priming apparatus to thereby prime the pump.
    Type: Grant
    Filed: January 6, 1998
    Date of Patent: January 4, 2000
    Assignee: Shop Vac Corporation
    Inventors: Randy L. Buss, Robert C. Berfield
  • Patent number: 5982270
    Abstract: A thermal fuse includes a first electrical contact extending through and engaged in electrical contact with a second contact. A spring is compressed between the first and second contacts. A thermally deformable pin retains the second contact against the compressed spring. The pin is responsive to a high temperature condition such that the pin deforms, thereby allowing the spring to disengage the first and second contacts.
    Type: Grant
    Filed: December 3, 1998
    Date of Patent: November 9, 1999
    Assignee: Shop Vac Corporation
    Inventors: Melvin E. Wolfe, Jr., Gary C. Berray, Robert C. Berfield
  • Patent number: 5966775
    Abstract: A vacuum cleaner has an electric motor driving an air impeller for creating suction and a pump impeller which draws liquid material through an inlet tube from the bottom of the tank and expels it from the tank. A removable plenum having openings separates the tank from the air impeller. A baffle is movable by a user to cover the openings to create a low pressure area above the plenum with respect to the pressure in the tank. The pump is located above the plenum and has an aperture in the pump housing. When the baffle covers the openings in the plenum, the air pressure differential drives the liquid material through the inlet tube into the pump housing thereby priming the pump.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: October 19, 1999
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 5920955
    Abstract: A vacuum cleaner has an electric motor driving an air impeller for creating suction and a pump which draws liquid material through an inlet tube from the bottom of the tank and expels it from the tank. A priming apparatus is disposed in the tank chamber in fluid communication with the pump and a valve is selectively actuable to establish a pressure differential across liquid in the priming apparatus to thereby prime the pump.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: July 13, 1999
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 5855634
    Abstract: A filter retainer for a vacuum cleaner includes a filter cage having several ribs. At the bottom of the filter cage is a lip which includes a plurality of notches. A cylindrical filter having open ends is slid over the filter cage. A cap is placed at the bottom of the filter in order to hold the filter to the filter cage. The cap has a pair of ramps which engage notches on the rim of the filter cage. As the cap is rotated, the cap is pushed towards the filter so that a lip on the cap engages a bottom of the filter.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: January 5, 1999
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 5850668
    Abstract: A vacuum cleaner has an electric motor driving an air impeller that creates low pressure inside the tank of the vacuum cleaner. The motor also drives a pump impeller which is located in the tank and draws liquid material from the bottom of the tank and expels it from the tank. Near an inlet to the pump is a priming mechanism having bellows which are compressed to force liquid material up into the pump. Portions of the pump, including the inlet and the outlet as well as the priming mechanism, are attached to a tank extension which fits over the top of the tank. The lid of the vacuum cleaner, which carries the motor and air impeller, fits over the tank extension when the vacuum cleaner is used for liquid material. The tank extension and its associated pump components are removable from the tank to facilitate use of the vacuum cleaner on dry material.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: December 22, 1998
    Assignee: Shop Vac Corporation
    Inventors: Robert C. Berfield, Randy L. Buss, Craig A. Seasholtz
  • Patent number: 5743019
    Abstract: A rotary flail feeding device includes a rotary enclosure for a large diameter coil of flail, a central post with a small diameter flail winding surface located inside the enclosure and an annular opening in the external surface of the enclosure surrounding the post. When the device is rotated flail from the coil is wound around the small diameter flail winding surface and extends out through the annular opening and away from the device.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 28, 1998
    Inventor: Robert C. Berfield
  • Patent number: 5715568
    Abstract: A vacuum apparatus includes a holding tank, a vacuum source, and a docking station. The tank holds material and has an interior and an exterior. The vacuum source draws the material from the exterior into the interior of the tank. The docking station docks a pump on the exterior of the tank so that, when the pump is docked in the docking station, the pump may be used to pump material out of the tank and so that the pump may be detached from the docking station for stand alone use.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: February 10, 1998
    Assignee: Shop Vac Corporation
    Inventors: Robert C. Berfield, Craig A. Seasholtz
  • Patent number: 5704090
    Abstract: A vacuum cleaner attachment for use in a suction line comprises a bleed section having an aperture extending into an interior portion of the attachment and a collar disposed in the bleed section. The collar is positionable in only a finite number of stable orientations wherein the collar covers the aperture in a first orientation and exposes the aperture in a second orientation.
    Type: Grant
    Filed: September 8, 1995
    Date of Patent: January 6, 1998
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 5675897
    Abstract: A rotary flail feeding device includes a head having an annular line storage cavity, a central post and annular line feeding passage extending radially inwardly from the cavity to a mouth at the end of the post. A coil of flail line is wound in the cavity and extends inwardly through the passage, around the post and out the opening. The device automatically relengthens shortened flails.
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: October 14, 1997
    Inventor: Robert C. Berfield
  • Patent number: 5647570
    Abstract: A mounting apparatus for a motor having a drive shaft comprises a neck surrounding the drive shaft and extending from the motor, a resilient collar circumferentially surrounding the neck and sized to be received by a collar receiving means, a boss extending from the motor and a resilient isolator having an axially extending central bore for receiving the boss and sized to be received by an isolator receiving means. Vibrations of the motor are isolated so that radiated noise and vibration are reduced.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: July 15, 1997
    Assignee: Shop Vac Corporation
    Inventors: Robert C. Berfield, Ronald F. Meland
  • Patent number: 5600866
    Abstract: A fluid tank assembly for use with a vacuum cleaner includes a tank and a spray nozzle interconnected with the tank by a tube. The assembly is adapted to be mounted on a suction nozzle of the vacuum cleaner.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: February 11, 1997
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 5555597
    Abstract: An apparatus for converting a vacuum cleaning apparatus having a first tank, a hose inlet and a suction source coupled to the hose inlet into a liquid dispensing and suctioning system includes a liquid holding tank for holding liquid, an attachment head having an outlet for dispensing liquid and an inlet for suctioning liquid, a housing attachable to the hose inlet and means including a pump disposed in the housing and coupled to the holding tank for delivering liquid from the holding tank to the outlet of the head.
    Type: Grant
    Filed: December 29, 1994
    Date of Patent: September 17, 1996
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: 5548868
    Abstract: A vacuum apparatus includes a holding tank for holding debris picked up by the vacuum apparatus, a lid cage for holding a filter between a vacuum inlet and a vacuum outlet of the vacuum device, a motor housing for housing a motor subassembly as a source of vacuum, attaching means for attaching one of the lid cage and the motor housing to the holding tank, and a detent cooperating with the motor housing and the lid cage for providing an indication to an assembler that the lid cage and the motor housing have been properly seated with respect to one another. A pilot is provided for guiding relative movement between the lid cage and the motor housing in order to facilitate the indication provided by the detent that the lid cage and the motor have been properly seated.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: August 27, 1996
    Assignee: Shop Vac Corporation
    Inventors: Robert C. Berfield, Alan D. Kaufman
  • Patent number: 5513416
    Abstract: A holder for a tank-type vacuum cleaner and attachments includes a first bracket for receiving a tank-type vacuum cleaner thereon, the first bracket being mountable to a surface, and a second bracket separate from but matingly engageable with the first bracket for receiving at least one vacuum cleaner attachment. The first and second brackets may be matingly engaged or the two brackets may be mounted to a wall separately from one another in a two-piece configuration.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: May 7, 1996
    Assignee: Shop Vac Corporation
    Inventors: Louis M. Bassler, Robert C. Berfield
  • Patent number: 5507071
    Abstract: A U-shaped handle is attachable to a motor housing by a first projection on the end of the handle that engages a tab on the inside of the housing and by a second projection on the inside of the handle that engages a vent on the side of the housing. The projections are located on opposite sides of a fulcrum point such that applying a force to disengage either of the projections reinforces the engagement of the other projection, making the handle difficult to remove from the motor housing.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: April 16, 1996
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield
  • Patent number: D389962
    Type: Grant
    Filed: August 14, 1996
    Date of Patent: January 27, 1998
    Assignee: Shop Vac Corporation
    Inventors: Robert C. Berfield, John Griffin
  • Patent number: D395119
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: June 9, 1998
    Assignee: Shop Vac Corporation
    Inventor: Robert C. Berfield