Patents by Inventor Li H. Liu

Li H. Liu 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: 9198552
    Abstract: A vacuum cleaner has a screen cage that is permanently attached to a lid that fits on a receptacle. The screen cage has multiple layers of screens with different screen sizes, including an inner support that has greater rigidity and larger apertures that the primary screen, and an outer screen that also has greater rigidity and larger apertures than the primary screen, and is made of a different material than the support. A replaceable filter mounts to a power head that can be removed from the lid while the lid remains attached to the receptacle, and nests in the screen cage. A thermal cutoff shuts the vacuum cleaner off when the temperature of air in a part of the flowpath exceeds a limit.
    Type: Grant
    Filed: April 24, 2012
    Date of Patent: December 1, 2015
    Assignee: SHOP VAC CORPORATION
    Inventors: Melvin E. Wolfe, Randy L. Buss, Li H. Liu
  • Patent number: 8707497
    Abstract: The disclosed bracket can be used to hang vacuum cleaners that have a detachable dolly. A plate on the bracket mounts to a wall. A stem portion fits within a slot on the dolly. Lower wall segments on the stem portion extend from the wall plate and have vertical outer edges. Intermediate wall segments extend between the lower wall segments and upper wall segments that have lower horizontal limits that are closer together than the lower wall segments are, are positioned laterally outwards from the stem portion, and taper toward each other above their lower limits. Side rim portions extend from the upper wall segments and fit within grooves on the vacuum cleaner. The outer edges of the lower wall segments are farther apart than the inner edges of the side rim portions are, and closer together than the outer edges of the side rim portions are.
    Type: Grant
    Filed: November 11, 2009
    Date of Patent: April 29, 2014
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Publication number: 20130276262
    Abstract: A vacuum cleaner has a screen cage that is permanently attached to a lid that fits on a receptacle. The screen cage has multiple layers of screens with different screen sizes, including an inner support that has greater rigidity and larger apertures that the primary screen, and an outer screen that also has greater rigidity and larger apertures than the primary screen, and is made of a different material than the support. A replaceable filter mounts to a power head that can be removed from the lid while the lid remains attached to the receptacle, and nests in the screen cage. A thermal cutoff shuts the vacuum cleaner off when the temperature of air in a part of the flowpath exceeds a limit.
    Type: Application
    Filed: April 24, 2012
    Publication date: October 24, 2013
    Applicant: SHOP VAC CORPORATION
    Inventors: Melvin E. Wolfe, Randy L. Buss, Li H. Liu
  • Patent number: 8533906
    Abstract: A vacuum cleaner comprising a receptacle having a working air inlet and an associated filter, the filter in communication with and downstream from the working air inlet, is disclosed. The vacuum cleaner further includes a housing containing a motor and having a cooling air outlet from the motor and a working air outlet, the working air outlet in communication with the working air inlet of the receptacle through a working air impeller, wherein the cooling air is directed to the receptacle, and the cooling air passes through the filter before exiting the working air outlet of the housing.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: September 17, 2013
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Publication number: 20130007984
    Abstract: A vacuum cleaner comprising a receptacle having a working air inlet and an associated filter, the filter in communication with and downstream from the working air inlet, is disclosed. The vacuum cleaner further includes a housing containing a motor and having a cooling air outlet from the motor and a working air outlet, the working air outlet in communication with the working air inlet of the receptacle through a working air impeller, wherein the cooling air is directed to the receptacle, and the cooling air passes through the filter before exiting the working air outlet of the housing.
    Type: Application
    Filed: July 7, 2011
    Publication date: January 10, 2013
    Applicant: SHOP VAC CORPORATION
    Inventor: Li H. Liu
  • Patent number: 8015661
    Abstract: A vacuum cleaner includes a tank having a bottom and an inlet for receiving debris, a motor assembly disposed adjacent to the tank, the motor assembly adapted to draw debris into the tank through the inlet, a battery pack disposed adjacent the bottom of the tank, and a connection from the battery pack to the motor assembly that is adapted to carry current between the battery pack and the motor assembly. The battery pack includes at least one battery and supplies power to the motor assembly.
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: September 13, 2011
    Assignee: Shop Vac Corporation
    Inventors: Mark E. Baer, Li H. Liu, Jonathan Miller
  • Publication number: 20110107547
    Abstract: The disclosed bracket can be used to hang vacuum cleaners that have a detachable dolly. A plate on the bracket mounts to a wall. A stem portion fits within a slot on the dolly. Lower wall segments on the stem portion extend from the wall plate and have vertical outer edges. Intermediate wall segments extend between the lower wall segments and upper wall segments that have lower horizontal limits that are closer together than the lower wall segments are, are positioned laterally outwards from the stem portion, and taper toward each other above their lower limits. Side rim portions extend from the upper wall segments and fit within grooves on the vacuum cleaner. The outer edges of the lower wall segments are farther apart than the inner edges of the side rim portions are, and closer together than the outer edges of the side rim portions are.
    Type: Application
    Filed: November 11, 2009
    Publication date: May 12, 2011
    Applicant: SHOP-VAC CORPORATION
    Inventor: Li H. Liu
  • Patent number: 7555809
    Abstract: A new vacuum cleaner/bracket combination has a bracket that mates with an indented side on a vacuum cleaner or blower. The indented side has a downwardly-facing upper lip portion and a laterally-facing side lip portion. There is an upper groove portion behind the downwardly-facing upper lip portion, and a side groove portion behind the side lip portion. The bracket has an upper rim portion that is configured to fit within the upper groove portion on the indented side. A side rim portion on the bracket is positioned below the upper rim portion. It is configured to fit within the side groove portion on the indented side when the upper rim portion on the bracket fits within the upper groove portion.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: July 7, 2009
    Assignee: Shop-Vac Corporation
    Inventor: Li H. Liu
  • Publication number: 20080276411
    Abstract: A new vacuum cleaner/bracket combination has a bracket that mates with an indented side on a vacuum cleaner or blower. The indented side has a downwardly-facing upper lip portion and a laterally-facing side lip portion. There is an upper groove portion behind the downwardly-facing upper lip portion, and a side groove portion behind the side lip portion. The bracket has an upper rim portion that is configured to fit within the upper groove portion on the indented side. A side rim portion on the bracket is positioned below the upper rim portion. It is configured to fit within the side groove portion on the indented side when the upper rim portion on the bracket fits within the upper groove portion.
    Type: Application
    Filed: May 9, 2008
    Publication date: November 13, 2008
    Applicant: Shop-Vac Corporation
    Inventor: Li H. Liu
  • Patent number: 6557206
    Abstract: A mounting assembly adapted to removably secure a vacuum cleaner to a support includes a mounting rack. The mounting rack has a surface located at its upper end that supports the vacuum cleaner in a suspended state. The mounting assembly also includes a retaining clip connected to the mounting rack. The retaining clip is movable between a first position and a second position. The retaining clip engages an outwardly extending portion of the vacuum cleaner in the first position, and disengages the outwardly extending portion in the second position.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: May 6, 2003
    Assignee: Shop Vac
    Inventor: Li H. Liu
  • Patent number: 6440191
    Abstract: A vacuum cleaner has a tank and a lid for closing off the tank. A motor/impeller unit is disposed inside the tank for generating an airstream. A filter support is attached to the lid and disposed inside the tank. A foam sleeve for removing liquid from the airstream is attached to the filter support. An air filter cartridge is removably attached to the filter support outside of the foam sleeve. The foam sleeve may remain in place as the filter cartridge is attached for dry pick-up or removed for wet pick-up. In addition, a drain hole is provided in the lid for draining liquid passing through the foam sleeve.
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: August 27, 2002
    Assignee: Shop Vac Corporation
    Inventors: Robert C. Berfield, Li H. Liu
  • Patent number: 6113663
    Abstract: A vacuum cleaner having a dual filter assembly includes a filter cage, a primary filter disposed on the filter cage, and a secondary filter disposed downstream of the primary filter. A float valve between the primary filter and the secondary filter inhibits liquid from coming into contact with the secondary filter.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: September 5, 2000
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Patent number: 6110248
    Abstract: A dual filter assembly for a vacuum cleaner includes an annular inner filter mountable on a filter cage of the vacuum cleaner. The inner filter has a lower end and a retaining ring is attached to the lower end. An annular outer filter is removably mounted surrounding the inner filter, with a lower end of the outer filter supported by the retaining ring.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: August 29, 2000
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Patent number: D520444
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: May 9, 2006
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Patent number: D521445
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: May 23, 2006
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Patent number: D521446
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: May 23, 2006
    Assignee: Shop Vac Corporation
    Inventor: Li H. Liu
  • Patent number: D537578
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: February 27, 2007
    Assignee: Shop Vac Corporation
    Inventors: Robert L. Crevling, Jr., John Griffin, Li H. Liu
  • Patent number: D581114
    Type: Grant
    Filed: September 22, 2006
    Date of Patent: November 18, 2008
    Assignee: Shop Vac Corporation
    Inventors: Robert Lent Crevling, Jr., Li H. Liu, John Griffin
  • Patent number: D683507
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: May 28, 2013
    Assignee: Shop Vac Corporation
    Inventors: Li H. Liu, Robert L. Crevling, Jr., John Griffin
  • Patent number: D688842
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: August 27, 2013
    Assignee: Shop Vac Corporation
    Inventors: Li H. Liu, Robert L. Crevling, Jr., John Griffin