Patents by Inventor Robert D. MacDonald
Robert D. MacDonald 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).
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Patent number: 5690051Abstract: A pet litter separation system provides an open-centered separation device having an upper end forming a mouth, a lower end covered by a separation member, and a sidewall interconnecting the ends. The member forms openings suitably sized for permitting passage of reusable pet litter granules while blocking passage of clumped waste. The cover has a first portion positionable inside the device in overlying relationship to the member so that the granules and clumps are prevented from exiting through the member when the used litter in a conventional litter tray is poured into the device for processing. Preferably the tray is completely emptied for thorough cleaning. The cover further includes a mechanism for facilitating removal of the first portion out from beneath the granules and clumps so that the reusable granules can pass through the member preferably directly back into the tray for preventing material loss. The waste clumps are dumped back out the upper end of the device for disposal.Type: GrantFiled: June 27, 1996Date of Patent: November 25, 1997Inventors: Greg L. Fisher, Robert D. MacDonald
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Patent number: 5386079Abstract: Wastewaters which are contaminated with heterocyclic aromatic compounds, especially wastewaters contaminated with biocidal heterocyclic aromatic compounds, or the by-products and intermediates thereof, can be treated to largely or even substantially completely degrade the heterocyclic aromatic rings by a process which comprises either adjusting the pH of said wastewaters to at least 11 and heating in a sealed vessel at a temperature of 120.degree. C. to 175.degree. C., or adjusting the pH of said wastewaters to 2.5 or less and heating in a sealed vessel at a temperature of 130.degree. C. to 175.degree. C., for an effective length of time.Type: GrantFiled: May 19, 1992Date of Patent: January 31, 1995Assignee: Ciba-Geigy CorporationInventors: Robert E. Munson, Robert D. Macdonald
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Patent number: 5343608Abstract: A method of forming an identification band from a tube with a constant circular cross-section along the majority of its outer circumference. The tube holds an indicia, and the information on the indicia is magnified by the generally circular shape of the tube. The circular shape also minimizes contact between the band and the wearer. Contact is limited to line contact with the skin, and irritation of the skin is reduced by eliminating any edges which may cut or scrape the skin. A method of forming the identification band includes the steps cutting a predetermined length of tube, placing an indicia therein, and completing the assembly by inserting an untapered cylindrical plug into each end of the tube.Type: GrantFiled: July 28, 1993Date of Patent: September 6, 1994Inventor: Robert D. MacDonald
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Patent number: 5323554Abstract: An inventive identification band includes a tube with a constant circular cross-section along the majority of its outer circumference. The tube holds an indicia, and the information on the indicia is magnified by the generally circular shape of the tube. The circular shape also minimizes contact between the band and the wearer. Contact is limited to line contact with the skin, and irritation of the skin is reduced by eliminating any edges which may cut or scrape the skin. A method of forming the identification band includes the steps of cutting a predetermined length of tube, placing an indicia therein, and completing the assembly by inserting an untapered cylindrical plug into each end of the tube.Type: GrantFiled: July 28, 1993Date of Patent: June 28, 1994Inventor: Robert D. MacDonald
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Patent number: 4981156Abstract: A mixing valve (10) has a modular cartridge (60) rotatably mounted in housin (12). The cartridge has a bottom volume control valve plate (58) attached to a lower section (62) housing a pressure balance valve (80). The lower section (62) is secured to an upper section (120) that rotatably receives a temperature control plate (150). The plates (58) and (150) are both rotatable about a common axis (64). The plate (58) is controlled by operation of stem (180) attached to handle (34). The plate (150) is controlled by stem (160) which is operated by knob (38). An insert (250) allows the knob (38) to operate even when hot and cold water supplies are inverted. A splined hot water stop ring (228) sits in handle (34) and adaptably limits rotation of knob (38) for a selected maximum water temperature. Outer seals (58) assure that all water flows through cartridge (60) when the volume is set for partial flow.Type: GrantFiled: November 17, 1989Date of Patent: January 1, 1991Assignee: Masco Corporation of IndianaInventors: James R. Nicklas, Robert D. MacDonald
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Patent number: 4901750Abstract: A mixing valve (10) has a modular cartridge (60) rotatably mounted in housing (12). The cartridge has a bottom volume control valve plate (58) attached to a lower section (62) housing a pressure balance valve (80). The lower section (62) is secured to an upper section (120) that rotatably receives a temperature control plate (150). The plates (58) and (150) are both rotatable about a common axis (64). The plate (58) is controlled by operation of stem (180) attached to handle (34). The plate (150) is controlled by stem (160) which is operated by knob (38). An insert (250) allows the knob (38) to operate even when hot and cold water supplies are inverted. A splined hot water stop ring (228) sits in handle (34) and adaptably limits rotation of knob (38) for a selected maximum water temperature. Outer seals (58) assure that all water flows through cartridge (60) when the volume is set for partial flow.Type: GrantFiled: September 30, 1988Date of Patent: February 20, 1990Assignee: Masco Corporation of IndianaInventors: James R. Nicklas, Robert D. MacDonald
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Patent number: 4699172Abstract: A valve assembly comprising a temperature responsive servomechanism adapted to combine hot and cold water under pressure to produce a constant preselected temperature of water at an outlet.The valve assembly comprises a housing having a valving cavity, a hot water inlet leading to the valving cavity, a cold water inlet leading to the valving cavity, and a mixed water outlet passageway leading from the valving cavity. A valve member translates in the valving cavity and divides the cavity into two auxiliary chambers. A passageway through the valve member allows fluid to flow from each of the inlets to the outlet passageway at a rate that varies as the valve member translates. Passageways in the valve member permit a portion of the mixed water to flow into the auxiliary chambers. An auxiliary passageway is provided between each of the auxiliary chambers and the outlet passageway. A temperature responsive element is provided within the outlet passageway.Type: GrantFiled: May 28, 1986Date of Patent: October 13, 1987Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4640457Abstract: A valve assembly comprising a temperature responsive servomechanism adapted to combine hot and cold water under pressure to produce a constant preselected temperature of water at an outlet.The valve assembly comprises a housing having a valving cavity, a hot water inlet leading to the valving cavity, a cold water inlet leading to the valving cavity, and a mixed water outlet passageway leading from the valving cavity. A valve member translates in the valving cavity and divides the cavity into two auxiliary chambers. A passageway through the valve member allows fluid to flow from each of the inlets to the outlet passageway at a rate that varies as the valve member translates. Passageways in the valve member permit a portion of the mixed water to flow into the auxiliary chambers. An auxiliary passageway is provided between each of the auxiliary chambers and the outlet passageway. A temperature responsive element is provided within the outlet passageway.Type: GrantFiled: February 27, 1984Date of Patent: February 3, 1987Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4562994Abstract: Three-piece stop valves, in both angle and straight-through forms, are disclosed comprising a valve body, resilient control sleeve and handle, with no separate fasteners or sealing elements being required. The handle and control sleeve are retained within the valve body by resilient formations on the handle which snap into a retaining groove on the valve body. Inlet line pressure resiliently biases the side walls of the control sleeve into sealing engagement with the valve bore to prevent leakage.Type: GrantFiled: March 18, 1985Date of Patent: January 7, 1986Assignee: Brass Craft Manufacturing CompanyInventor: Robert D. MacDonald
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Patent number: 4561203Abstract: An illuminated sign with an opaque sign plaque employs a light source overlying the sign plaque embraced by a concave downward facing reflector, and a flat lower reflector underlying the sign plaque, providing both direct and reflected illumination over the face of the sign plaque. In its preferred form, the concave reflector is compoundly curved over the ends of the sign plaque and the flat lower reflector is tilted toward the sign plaque.Type: GrantFiled: August 4, 1983Date of Patent: December 31, 1985Assignee: Dual-Lite ManufacturingInventors: Robert D. MacDonald, Jr., William A. Luca, Robert M. Johnstone
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Patent number: 4458839Abstract: A valve assembly comprising a temperature responsive servo-mechanism adapted to combine hot and cold water under pressure to produce a constant preselected temperature of water at an outlet.The valve assembly comprises a housing having a valving cavity, a hot water inlet leading to the valving cavity, a cold water inlet leading to the valving cavity, and a mixed water outlet passageway leading from the valving cavity. A valve member translates in the valving cavity and divides the cavity into two auxiliary chambers. A passageway through the valve member allows fluid to flow from each of the inlets to the outlet passageway at a rate that varies as the valve member translates. Passageways in the valve member permit a portion of the mixed water to flow into the auxiliary chambers. An auxiliary passageway is provided between each of the auxiliary chambers and the outlet passageway. A temperature responsive element is provided within the outlet passageway.Type: GrantFiled: March 3, 1982Date of Patent: July 10, 1984Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4453567Abstract: A valve assembly has a first ceramic valve member having a flat valving surface. An aperture open to the valving surface is provided through the valve member. The valve assembly further has a tubular valve member having an aperture therethrough, and an annular valving surface adjacent to the valving surface of the other valve member. The apertures through the respective valve members are moved into and out of registry with each other by relative movement therebetween. Preferably, a valve body is provided having a large bore accepting the first valve member and a small bore accepting the tubular valve member. The apertures are movable into and out of registry by rotation of the first valve member within the large bore.Type: GrantFiled: March 29, 1982Date of Patent: June 12, 1984Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4429712Abstract: A faucet for controlling the rate of discharge of a fluid under pressure. The faucet has a housing having a passageway therethrough with an inlet port coupled to a fluid supply line. The passageway further has an outlet port open to the ambient atmosphere. A valve seat is formed intermediate the inlet port and the outlet port. A slideway is provided in the housing adjacent to the seat. A flat cantilever spring has one of its ends secured to said housing, the other of its ends overlying said seat, and its intermediate portion disposed within the slideway. A movable element is disposed within the slideway and engages one surface of the spring. The movable element is selectively movable within the slideway along the surface of the spring to regulate the rate of discharge of fluid by varying the distance between the end of the spring and the seat.Type: GrantFiled: March 12, 1981Date of Patent: February 7, 1984Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4396353Abstract: A sump pump includes a submersible electric motor for driving an impeller which discharges water radially outward into a volute oriented in a horizontal plane at the bottom of the device. An optical sensor located at a predetermined pump-operating level utilizes the light reflecting and refracting properties of the sensor-chamber interface to sense the presence or absence of water at such level. In a first embodiment, the pump includes a supplementary water level-sensing chamber which has a first leg ascending from an inlet near its lower end to an overflow point at the top of a vertical barrier separating the first leg from a second leg which descends to the low pressure area of the impeller.Type: GrantFiled: April 13, 1981Date of Patent: August 2, 1983Assignee: Flint & Walling, Inc.Inventor: Robert D. MacDonald
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Patent number: 4287641Abstract: A door hinge of the type adapted to urge a door to its closed position and to hold the door closed without the necessity of employing a latch mechanism. The hinge comprises a hinge member having an integral hinge pin portion formed thereon, a second hinge member having hinge portions rotatably mounted on the hinge pin, and a pressure member mounted on the second hinge member nd reacting against the first hinge member to urge the door to a closed position, the pressure member being operable to hold the hinge members in assembled condition.Type: GrantFiled: August 20, 1979Date of Patent: September 8, 1981Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4200169Abstract: This invention relates to a stethoscope having improved acoustical properties. The improvement comprises twin, smooth-walled sound pathways extending from the chestpiece to the ear tips which are free of sound leakage and each pathway has a constant diameter along its entire length.Type: GrantFiled: October 16, 1978Date of Patent: April 29, 1980Assignee: Minnesota Mining and Manufacturing CompanyInventors: Robert D. MacDonald, III, Frederick W. Nelson
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Patent number: 4192052Abstract: The fins of a heat exchanger are brazed to the exterior of the fluid-carrying tube by means of a lower melting point cladding on the tube which forms a secure bond between the tube surface and the unconfigured portion of the perimeter of the tube-receiving holes in the fins. The fins have a limited number of narrow tabs doubled back from the edge of each hole to function as longitudinal spacers between adjacent fins.Type: GrantFiled: July 22, 1977Date of Patent: March 11, 1980Assignee: E. I. Du Pont de Nemours and CompanyInventor: Robert D. MacDonald
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Patent number: 4163474Abstract: Fluid-carrying tubes for a heat exchanger are provided with internal longitudinal fins formed separately from the tube itself. One form utilizes individual elongated V-shaped strips biased radially outwardly by an annular sheet metal spring, with the tips of the fins brazed to the inner surface of the tube wall. Second and third embodiments utilize a one-piece corrugated sheet metal cylinder rather than individual strips, but with adjacent fins being almost completely severed from each other to provide sharp edge contact between the tips of the fins and the tube wall for optimum brazing. Either the fins or tube inner wall is clad with a lower-melting point material which permits furnace brazing of the fin tips to the tube wall. All three forms have longitudinally spaced holes and slots to enhance heat exchange by inducing transverse fluid flow through the fins and to allow liquid levels to equalize.Type: GrantFiled: June 9, 1977Date of Patent: August 7, 1979Assignee: E. I. Du Pont de Nemours and CompanyInventors: Robert D. MacDonald, Robert K. Rose, John W. Papsdorf
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Patent number: 4103392Abstract: An apparatus for automatically closing a door with respect to a fixed support adjacent thereto which includes a torsional spring, a one-way clutch mechanism and a swash plate hydraulic damper concealably retained within a compact housing. The housing is secured to either the door or the fixed support and a first rotatable portion of the one-way clutch is coupled to the other of either of the door or fixed support so that the first rotatable portion rotates in a first direction when the door is opened in the opposite direction when the door is closed. The torsional spring is at least partially disposed about the one-way clutch mechanism and has one end anchored to the housing and the other end secured for movement with the first rotatable portion. As the door is opened, the first rotatable portion is rotated in the first direction to wind up the torsional spring. When the door is released, the torsional spring unwinds to reverse the process and close the door.Type: GrantFiled: October 26, 1976Date of Patent: August 1, 1978Assignee: Masco CorporationInventor: Robert D. MacDonald
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Patent number: 4005748Abstract: Annular fins for a heat exchanger are fabricated in circumferential segments, arranged end to end, with each segment having inner and outer edges of identical but radially spaced contour, so that such segments can be stamped from a blank without any scrap created between the common edges of adjacent segments.Type: GrantFiled: March 14, 1975Date of Patent: February 1, 1977Assignee: Champion Home Builders Co.Inventors: Robert D. MacDonald, Robert K. Rose