Vacuum Cleaner Patents (Class 417/423.2)
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Patent number: 11867197Abstract: A fan motor includes: a motor including a stator and a rotor, a motor housing accommodating the motor, a bearing case disposed at a lower portion of the motor housing, an impeller coupled to a rotary shaft of the motor, a vane structure disposed at a lower side of the impeller and configured to guide air, and a lead cable connector provided in the bearing case. The stator of the motor includes a core and a coil that is wound on the core, and the lead cable connector is connected to a lead cable of the coil of the stator.Type: GrantFiled: February 2, 2021Date of Patent: January 9, 2024Assignee: LG Electronics Inc.Inventors: Jin Hong, Kwangyong Jang, Yongdae Kim, Sunggi Kim
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Patent number: 11585342Abstract: A dry type primary vacuum pump is provided, including at least two pumping stages mounted in series between a suction and a discharge of the pump; two rotors extending in the pumping stages and being configured to rotate synchronously in a reverse direction to drive a gas to be pumped between the suction and the discharge; an injection device configured to distribute a purge gas in at least one pumping stage, the injection device including at least one injector and at least one injection valve with an on or off control configured to be interposed between a purge gas supply source and the injector; and a control device configured to control opening and closing of the injection valve to inject a purge gas by successive pulses into the at least one pumping stage. A method for controlling the injection of a purge gas the vacuum pump is also provided.Type: GrantFiled: September 26, 2019Date of Patent: February 21, 2023Assignee: PFEIFFER VACUUMInventors: Serge Brandolin, Eric Mandallaz
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Patent number: 11464379Abstract: Applicant has created vacuum apparatuses with improved stability and methods for improving the stability of a wet/dry vacuum. In one embodiment, the apparatus includes a motor, a removable drum adapted to store debris collected by the apparatus, and a base that can be adapted to receive the removable drum. The motor can be adapted to be interposed between the removable drum and the base. The methods can include the step of providing a base, the step of providing a removable drum adapted to be coupled to the base, and the step of coupling a vacuum motor to the base such that the vacuum motor is adapted to be disposed beneath the removable drum when the drum is coupled to the base. By relocating the motor of vacuum apparatus beneath the drum, the vacuum's center of gravity can be lowered significantly and, thus, its propensity to tip over is minimized.Type: GrantFiled: June 15, 2020Date of Patent: October 11, 2022Assignee: Emerson Electric Co.Inventor: Mark Tomasiak
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Patent number: 11454246Abstract: An electric blower includes an air blowing unit including a mixed-flow fan to generate a current of air, a motor to rotate the mixed-flow fan, and a housing including a first portion surrounding the mixed-flow fan in a circumferential direction, and a second portion surrounding the motor in the circumferential direction. The inner diameter of the second portion is smaller than the inner diameter of the first portion.Type: GrantFiled: June 22, 2017Date of Patent: September 27, 2022Assignee: Mitsubishi Electric CorporationInventors: Kazuchika Tsuchida, Naho Adachi
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Patent number: 11116367Abstract: An electric fan and a vacuum cleaner having the same are provided. The electric fan includes: a cover having an open side; an impeller disposed in the cover; a diffuser including a diffuser body and a plurality of vanes, the diffuser body being located at a side of the impeller adjacent to the cover, the plurality of vanes being disposed at an end of the diffuser body adjacent to impeller and spaced apart from one another along an outer circumference of the impeller, an outlet angle of each vane being denoted as ?, and ? satisfying: 45°???90°; and a refluxer disposed at an end of the diffuser body away from the impeller. The electric fan reduces flow losses of airflow, and improves work efficiency.Type: GrantFiled: December 27, 2018Date of Patent: September 14, 2021Assignee: MIDEA GROUP CO., LTD.Inventors: Lele Ming, Xiaowen Hu, Hui Zhang, Xiaoyin Han
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Patent number: 10731281Abstract: A heat dissipation apparatus for a sewing machine including a forepart and a motor shaft horizontally projecting out of the forepart includes a sleeve releasably secured to the motor shaft and including a first fan mounted thereon; a stator seat including an axial channel with the sleeve rotatably disposed through, and a plurality of first air inlets; and a guide member fastened between the stator seat and the forepart and including a disc-shaped opening with the first fan rotatably disposed therein. In response to activating the first fan, air is drawn through the first air inlets and a gap between the stator seat and the guide member prior to exiting the forepart.Type: GrantFiled: September 26, 2018Date of Patent: August 4, 2020Assignee: H. S. MACHINERY CO., LTD.Inventor: Tzu Sang Chan
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Patent number: 9558969Abstract: A pumping device intended to be connected to a process chamber (2) includes a dry primary vacuum pump, an auxiliary pump mounted so that the auxiliary pump bypasses a check valve on the vacuum pump, a first valve device connected to a purging device for purging the dry primary vacuum pump and intended to be connected to a gas supply, a second valve device mounted so that the second valve device bypasses a check valve upstream from the auxiliary pump, and a controller configured to control the first and second valve devices on the basis of an operating status of the process chamber in such a way that the first valve device is at least partially closed and the second valve device is open when the process chamber is operating at ultimate vacuum. Also a method for pumping of a process chamber by way of such a pumping device.Type: GrantFiled: July 15, 2013Date of Patent: January 31, 2017Assignee: ADIXEN VACUUM PRODUCTSInventor: Bertrand Seigeot
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Patent number: 9387298Abstract: A fan unit that forms part of a gases supply unit used as part of a breathing assistance system for providing heated gases to a user. The fan has an impeller surrounded by an upwardly sloped surface to facilitate improved airflow performance under surge conditions.Type: GrantFiled: April 29, 2010Date of Patent: July 12, 2016Assignee: FISHER & PAYKEL HEALTHCARE LIMITEDInventor: Johannes Nicolaas Bothma
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Patent number: 8939736Abstract: A fuel pump assembly may include a housing and a fuel pump within a fuel pump cavity. The fuel pump may include a motor, a pumping element driven for rotation by the motor, a pump body that maintains the position of the pumping element relative to the motor and the housing, and a flexible seal. The seal may be disposed between the pump body and the housing to provide a fluid tight seal between them. A portion of the seal may be disposed radially outwardly of a distal end of the pump body to radially position the pump body within the fuel pump cavity and a portion of the seal may be disposed axially outwardly of the distal end of the pump body to axially position the pump body within the fuel pump cavity.Type: GrantFiled: November 30, 2011Date of Patent: January 27, 2015Assignee: Walbro Engine Management, L.L.C.Inventors: Kevin L. Israelson, Douglas W. Salowitz, Jr., David L. Speirs
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Patent number: 8905727Abstract: Isolated pressure compensating electrical motor connections and related methods are provided. According to an example of a sealed motor electrical connection, the connection incorporates a sealed female motor connection positioned to receive a male motor connector. The female motor connector has one or more independent dielectric oil chambers each pressure compensated by a bellow or similar device interfaced with the motorhead oil and/or well annulus fluid to thereby pressure compensate the chamber pressure of the female motor connection with that of the internal motor and/or well annulus. This configuration locates the electrical connection point of the motor lead extension with the motor lead wires to a separate area outside the motor to thereby prevent the occurrence of phase to phase or phase to ground shorts occurring in this critical area due to conductive element contamination that may reside in the motor oil or the well bore fluids.Type: GrantFiled: July 19, 2012Date of Patent: December 9, 2014Assignee: Baker Hughes IncorporatedInventors: Jeffrey G. Frey, Ryan P. Semple
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Patent number: 8499412Abstract: An electric blower includes a stator, a rotor, a bracket, rotary fan, air guide, a fan case covering air guide and rotary fan. Air guide includes a partition plate, a diffuser, a partition slope, and a guide vane. Diffuser vanes configure closed passages. Passage lengths of closed passages include a first passage length and a second passage length that is different from the first passage length.Type: GrantFiled: December 26, 2011Date of Patent: August 6, 2013Assignee: Panasonic CorporationInventors: Shizuka Yokote, Michihiro Kurokawa, Akira Yamaguchi
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Publication number: 20130171013Abstract: Disclosed herein is a motor assembly for a vacuum cleaner, the motor assembly including: an inlet introducing air therethrough; a motor; an impeller installed on a shaft of the motor and including a plurality of blades disposed at predetermined intervals between a pair of plates facing each other so that it rotates by the motor to suck the air; a diffuser disposed at an outer side of a discharge hole formed at an edge of the impeller; a first fan including a plurality of blade parts disposed at predetermined intervals while having the shaft as a concentric axis and disposed beneath the diffuser; and an outlet discharging the air to the outside.Type: ApplicationFiled: April 5, 2012Publication date: July 4, 2013Applicant: Samsung Electro-Mechanics Co., Ltd.Inventors: Su Bong Jang, Han Kyung Bae, Hee Soo Yoon, Chang Hwan Park, Sang Jong Lee, Young Bok Yoon, Jin Su Seok
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Patent number: 8272854Abstract: This impeller-free vacuum cleaner is based on a rotary piston. Vacuum suction of 300 inches of water or better can be delivered. Quietness of below 70 db can be delivered. Tongued rotary piston assemblies may be strategically placed, such as stacked, to eliminate vacuum suction dead zones. Sealing problems that otherwise were encountered with previous reciprocating and rotary piston structures for vacuum cleaners are solved by using a tongued rotary piston with a double-notched rotary valve operating by a Geneva mechanism, and a novel pancake-shaped cylindrical structure to house the rotary piston. An inventive rotary combustion engine also is disclosed.Type: GrantFiled: April 29, 2005Date of Patent: September 25, 2012Inventor: Charles A. Castronovo
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Publication number: 20100209271Abstract: A fan motor apparatus of a vacuum cleaner having a diffuser unit is provided. The fan motor apparatus of a vacuum cleaner includes a fan motor unit into and from which an air stream is introduced and discharged in the same direction, and a diffuser unit having an air suction area to discharge an air stream to the fan motor unit through a fluid passage surface, the fluid passage surface through which an air stream is drawn in and discharged out of the diffuser. An air discharge area of the diffuser unit may receive the air stream discharged from the fan motor unit, and distribute and discharge the air stream through a perimeter of the air suction area of the fluid passage surface.Type: ApplicationFiled: December 18, 2009Publication date: August 19, 2010Inventor: Dong-hun YOO
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Patent number: 7736133Abstract: Upstream and downstream pump assemblies are mounted in a capsule having a bulkhead between the upstream and downstream pump assemblies, dividing the capsule into upstream and downstream chambers sealed from each other. In a dual operation mode, well fluid flows through the inlet of the capsule into the upstream chamber, where it is pumped to a first pressure level by the upstream pump assembly and discharged into the downstream chamber. The downstream pump assembly then pumps the well fluid to a second pressure level and discharges the well fluid out the outlet of the capsule. The assembly has also an upstream pump assembly only operational mode and a downstream pump assembly only operational mode.Type: GrantFiled: May 17, 2007Date of Patent: June 15, 2010Assignee: Baker Hughes IncorporatedInventor: Ignacio Martinez
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Patent number: 7651325Abstract: In a vacuum cleaner blower (1) consisting of an electric drive motor (2) and a support cage (10) for receiving the structural modules of the drive motor such as stator pack (6), rotor (7) and brush holders (8) including carbon brushes (9) as well as an at least single stage blower unit driven by the motor including a deflector (11), impeller (12) and suction hood (4), the deflector being formed as a support cage lid including a bearing seat for the rotor (7) and the support cage (10) being formed for a mounting direction (C) of its structural modules in the axial direction of the blower and for direct contacting and the brush holder (8) of the carbon brushes being provided adjacent to the upper side (B) of the support cage which also faces the deflector (11).Type: GrantFiled: October 27, 1999Date of Patent: January 26, 2010Assignee: Miele & Cie. KGInventors: Guenter Esch, Peter Rode, Hans-Joachim Hegemann
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Patent number: 7481630Abstract: A housing for a hand held vacuum cleaner is so constructed that a suction motor mounting bracket which is enclosed by a lower housing section, is removably secured to an upper housing section. A suction coupling pipe section is either an integral part of or directly secured to the suction motor mounting bracket, so that forces introduced to a suction tool attached to the suction coupling pipe section are transmitted through the mounting bracket to the upper housing section thereby at least partly relieving the lower housing section from forces passing from the suction tool to the handle and vice versa.Type: GrantFiled: September 23, 2005Date of Patent: January 27, 2009Assignee: Stein & Co. GmbHInventors: Achim Liffers, Bernd Falkenstein
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Publication number: 20090022590Abstract: A method of manufacturing an electrical suction unit for use in a vacuum cleaner includes a turbine unit and an electrical motor with a rotor and a stator. The turbine unit is attached to the rotor and forms, together with the rotor, a rotatable part of the suction unit, which is rotatable about an axis of rotation. An amount of material is removed from the rotor and from the turbine unit to torque-balance the rotatable part of the suction unit. In this manner, the amount of material to be removed from the rotor to torque-balance the rotatable part is considerably reduced, so that the adverse influence of the removal of the material from the rotor on the performance of the electrical motor is limited.Type: ApplicationFiled: September 19, 2008Publication date: January 22, 2009Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventor: WESSEL ADOLF OTTEN
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Publication number: 20090010782Abstract: A vacuum cleaner fan with an electric drive motor having a stator assembly and a rotor. The stator assembly and rotor are disposed in a bearing pot. An at least single-stage fan unit is driven by the electric motor. The fan unit includes a guide stage, a suction cap, and an impeller that is configured to generate an air stream. The bearing pot includes a receiving pocket which holds an adapter housing. The adapter housing accommodates a printed circuit board. A power semiconductor operable to control rotational speed of the fan unit is included on the printed circuit board. At least a portion of the power semiconductor protrudes from the adapter housing into the vicinity of the air stream generated by the fan unit.Type: ApplicationFiled: February 23, 2006Publication date: January 8, 2009Applicant: MIELE & CIE. KGInventors: Klaus Bartsch, Manfred Gerhards, Friedhelm Sicken
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Patent number: 7418763Abstract: A hand-held portable vacuum having a filter indicator that is coupled to an outlet housing and in fluid communication with a portion of the outlet housing between a fan inlet and an intake. The filter indicator includes a pressure differential indicator that is configured to indicate a pressure differential between air in the portion of the outlet housing and atmospheric air pressure. The filter indicator is employed to indicate to the user of the hand-held vacuum that replacement and/or cleaning of the filter is required. The vacuum may also be used in a blower mode with a set of inflator nozzles to permit a user to inflate an article.Type: GrantFiled: February 25, 2004Date of Patent: September 2, 2008Assignee: Black & Decker Inc.Inventors: David M. Shaver, Jacob R. Prosper, Murray D. Hunter, Carolyn Martin, Patrick W. Mooney, Olga Makeev
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Patent number: 7416384Abstract: An electric blower includes an electric motor including a stator and a rotor. The impeller is rotated by the electric motor. An air guide having a plurality of guide blades is disposed around the impeller, and a casing encloses the impeller and the air guide. The casing is provided with a number of exhaust openings through which a part of an air stream suctioned by the impeller is discharged, and a circumferential length of each of the exhaust openings is substantially identical to a circumferential distance between outer peripheral ends of adjacent guide blades. Alternatively, the circumferential length of each of the exhaust openings may be less or greater than the circumferential distance between outer peripheral ends of adjacent guide blades.Type: GrantFiled: September 22, 2003Date of Patent: August 26, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tsuyoshi Tokuda, Yoshitaka Murata, Yoshitaka Hayamizu, Kazuhisa Morishita, Yasuhiro Yuasa, Norihiro Tsuchiya
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Publication number: 20080138202Abstract: An arrangement for supporting a shaft of a vacuum pump includes a first bearing for supporting the shaft at one of its end, a second bearing for supporting the shaft at another of its ends and formed as a rolling bearing, a holder for receiving the second bearing and including an oscillating base, a fixation member secured in the vacuum pump housing, metallic connection members for connecting the oscillating base with the fixation member and axial springs arranged between the oscillating base and the fixation member and providing for the axial stiffness of the holder which is greater than its radial stiffness thereof and greater than the axial stiffness of the first bearing.Type: ApplicationFiled: August 6, 2007Publication date: June 12, 2008Inventors: Martin Eilers, Andreas Rippl, Christopher-Mark Rippl, Tobias Stoll
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Publication number: 20080050252Abstract: Disclosed are a bearing housing, and a motor assembly and a vacuum cleaner having the same. The motor assembly includes: a motor housing; a motor installed in the motor housing, for supplying suction force; an impeller rotatably installed on a rotation shaft of the motor; an impeller cover coupled to the motor housing, for covering the impeller; a guide vane installed between the motor and the impeller, and composed of a plurality of diffuser vanes for converting some of dynamic pressure of the air passing through the impeller into static pressure, and a plurality of return vanes formed on the bottom surfaces of the diffuser vanes, for forming passages for guiding the air with its pressure raised by the diffuser vanes to the motor side; and a bearing housing including a passage formation unit for forming passages by contacting the bottom ends of the return vanes, and a shaft support unit for supporting the rotation shaft of the motor.Type: ApplicationFiled: December 27, 2006Publication date: February 28, 2008Applicant: LG ELECTRONICS INC.Inventor: Kwang-Woon AHN
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Patent number: 7104768Abstract: A Peristaltic micropump includes a first membrane region with a first piezo-actor for actuating the first membrane region, a second membrane region with a second piezo-actor for actuating a second membrane region, and a third membrane region with a third piezo-actor for actuating the third membrane region. A pump body forms, together with the first membrane region, a first valve whose passage opening is open in the non-actuated state of the first membrane region and whose passage opening may be closed by actuating the first membrane region. The pump body forms, together with the second membrane region, a pumping chamber whose volume may be decreased by actuating the second membrane region. The pump body forms, together with the third membrane region, a second valve whose passage opening is open in the non-actuated state of the third membrane region and whose passage opening may be closed by actuating the third membrane region. The first and the second valve are fluidically connected to the pumping chamber.Type: GrantFiled: October 6, 2004Date of Patent: September 12, 2006Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.Inventors: Martin Richter, Martin Wackerle, Yücel Congar, Julia Nissen
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Patent number: 6920867Abstract: An air intake apparatus for supplying air to an internal combustion engine comprises a hollow plastics material enclosure, an air filter and an air compressor which when activated compresses air supplied to the engine. The enclosure houses the air filter and compressor. An engine air supply path through the enclosure passes from an air inlet to the enclosure to an air outlet from the enclosure via the air filter. The enclosure inlet and enclosure outlet define respectively an upstream end of the air supply path and a downstream end of the air supply path, wherein the compressor is secured within the enclosure by resilient vibration-isolating mounts.Type: GrantFiled: July 26, 2001Date of Patent: July 26, 2005Assignee: Visteon Global Technologies, Inc.Inventors: Kevin Paul Cutts, Olivier Henri Eugene Desmons, Scott John Moore, John Charles New, James Justin Tindall
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Patent number: 6843644Abstract: Disclosed is a mounting structure of a blower for a vacuum cleaner comprising a mounting cover for fixing the blower to a body base so that the blower is structurally separated from a body cover. The mounting cover is put on the upper surface of the blower disposed on supporting ribs, and connected to the body base, and then the body cover is put on the body base. The blower is fixedly interposed between the supporting ribs and the mounting cover and separated from the body cover, thereby preventing oscillation generated by the blower from being transmitting to the body cover and then preventing the oscillation of the body cover and the consequently occurring noise of the body cover.Type: GrantFiled: January 22, 2003Date of Patent: January 18, 2005Assignee: LG Electronics Inc.Inventors: Ho Seon Rew, Hyeun Sik Nam, Yong Woo Lee
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Patent number: 6786706Abstract: A fan in which, on one end of the motor shaft 6 a stepped portion 19 having a small diameter is formed, on which a central portion of the motor yoke 11 is press-fitted and fixed by caulking, thereby the motor yoke is mounted directly on the shaft 6. By such a structure, the conventional boss between the shaft 6 and the motor yoke 11 can be omitted and the structure can be simplified.Type: GrantFiled: October 15, 2002Date of Patent: September 7, 2004Assignee: Minebea Co., Ltd.Inventors: Kiyoshi Shinokubo, Shoichi Takei
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Patent number: 6736615Abstract: A fan/motor assembly having an integrated brush support and bearing retainer is disclosed. The fan/motor assembly includes a rotatable shaft, a working air fan coupled to the shaft, and a motor bracket and baffle assembly interposed between the working air fan and the motor assembly. The motor bracket and baffle assembly retains a bearing which rotatably receives the shaft and provides integral brush boxes for the motor assembly.Type: GrantFiled: November 8, 2002Date of Patent: May 18, 2004Assignee: Ametek, Inc.Inventors: Robert A. Ciccarelli, Jr., David B. Finkenbinder, William H. McCloud, Jr.
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Patent number: 6508618Abstract: A pump has a housing defining a pump chamber and having a shaft opening. An impeller shaft extends through the shaft opening and is sized to define a gap between the impeller shaft and the shaft opening. An impeller is attached to the shaft inside the pump chamber. The impeller includes a first set of impeller blades for transporting fluid through the pump chamber and a second set of impeller blades for creating a pressure force which pushes fluid away from the shaft opening. The pump with sealless shaft prevents fluid from leaking through the gap, and therefore is particularly suited for use in a tank-type vacuum cleaner capable of collecting both dry material and fluid. The gap is used in such an application to prime the pump, thereby discharging fluid collected in the tank.Type: GrantFiled: February 20, 2001Date of Patent: January 21, 2003Assignee: Shop-Vac CorporationInventor: Robert C. Berfield
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Patent number: 6378164Abstract: A pump inlet fitting for a wet/dry vacuum cleaner is disclosed. The pump inlet fitting frictionally attaches a pump inlet assembly to an inner surface of an intake tube of a wet/dry vacuum cleaner. The pump inlet fitting includes a plurality of radially extending barbs which frictionally engage the inner surface of the intake tube to a degree sufficient to secure the pump inlet assembly to the intake tube without the need for costly and time consuming external clamping mechanisms.Type: GrantFiled: July 18, 2000Date of Patent: April 30, 2002Assignee: Shop Vac CorporationInventor: Robert C. Berfield
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Patent number: 6368066Abstract: A vacuum apparatus has a recessed portion which is provided at an appropriate position of a fan casing. When incoming materials frequently pass through the fan casing, the recessed portion wears more quickly than the rest of the inner surface of the fan casing. Hence, a user of the vacuum apparatus can easily know when to replace the fan casing by visually checking the recessed portion from outside the fan casing.Type: GrantFiled: December 7, 1999Date of Patent: April 9, 2002Assignee: Kioritz CorporationInventors: Fumihiko Aiyama, Kazunori Takahashi
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Patent number: 6264427Abstract: A vacuum cleaner includes a driven impeller that moves working air for the vacuum cleaner. A first housing includes a first wall and a second housing includes a second wall opposite the first wall, and an outlet for the working air. The impeller rotates and draws the working air through an opening and directs the working air radially outwardly toward the first wall and then through an annular passage formed between the first wall and the second wall. The annular passage restricts the flow of working are to provide back pressure on the impeller.Type: GrantFiled: February 10, 1999Date of Patent: July 24, 2001Assignee: Shop-Vac CorporationInventor: Robert C. Berfield
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Patent number: 6249933Abstract: A pump has a housing defining a pump chamber and having a shaft opening. An impeller shaft extends through the shaft opening and is sized to define a gap between the impeller shaft and the shaft opening. An impeller is attached to the shaft inside the pump chamber. The impeller includes a first set of impeller blades for transporting fluid through the pump chamber and a second set of impeller blades for creating a pressure force which pushes fluid away from the shaft opening. The pump with sealless shaft prevents fluid from leaking through the gap, and therefore is particularly suited for use in a tank-type vacuum cleaner capable of collecting both dry material and fluid. The gap is used in such an application to prime the pump, thereby discharging fluid collected in the tank.Type: GrantFiled: August 26, 1999Date of Patent: June 26, 2001Assignee: Shop Vac CorporationInventor: Robert C. Berfield
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Patent number: 6232696Abstract: A vacuum generating apparatus for a vacuum cleaner is provided, in which an axial type coreless brushless direct-current (DC) motor is implemented in the form of a rotor-impeller integration structure. The vacuum generating apparatus includes an axial type brushless DC motor in which disc-shaped upper and lower rotors are symmetrically disposed facing the upper and lower portions of a disc-shaped stator at either end of a rotating shaft rotatably supported in the inner circumferential portion of the stator, upper and lower impellers integrally fixed in the upper and lower rotors, respectively, and upper and lower housings whose outer circumferential portions are combined with the outer circumferential portions of the respective disc-shaped stator such that air sucked via sucking inlets formed at the center of the housings is guided to a discharging outlet together with the stator. A single rotor structure can also be adopted.Type: GrantFiled: July 23, 1999Date of Patent: May 15, 2001Assignee: Amotron Co., Ltd.Inventors: Byung Kyu Kim, Joon Kim