Patents Represented by Attorney Ronald J. LaPorte
  • Patent number: 4250540
    Abstract: An arrangement for mounting an enclosed light fixture housing having an open end with a flange formed about the periphery thereof, in recessed fashion in an aperture defined in a planar support member having inner and outer surfaces, with the flange of the housing engaging the outer surface, includes a side wall of the housing defining a T-shaped slotted aperture with the longer leg of the T extending from the shorter leg toward the open end of the housing, and having ratchet teeth formed along an edge of the longer leg of the T, and a mounting clip receivable in the slotted aperture from the interior of the housing after the housing is received in the aperture in the support member. The mounting clip is captured in the slotted aperture and slidable toward and away from the inner surface of the support member.
    Type: Grant
    Filed: August 23, 1979
    Date of Patent: February 10, 1981
    Assignee: McGraw-Edison Co.
    Inventor: Paul J. Kristofek
  • Patent number: 4249120
    Abstract: A variable speed induction motor control system includes a variable voltage DC bridge coupled to a frequency controlled power inverter which in turn drives an induction motor. A motor power factor detecting circuit determines the relative voltage/current phase angle for the motor and derives a corresponding power factor error signal. The DC bridge and inverter respond to the power factor error signal to maintain the input power conditions of the motor at a near optimum efficiency. The power factor detecting circuit uses an exclusive OR gate to provide a pulse having a duration corresponding to the motor power factor which enables a counter during the pulse interval. After each pulse, the count which is indicative of the motor power factor, is applied to a holding circuit and converted to an analog error voltage.
    Type: Grant
    Filed: July 26, 1979
    Date of Patent: February 3, 1981
    Assignee: McGraw-Edison Co.
    Inventor: Kent L. Earle
  • Patent number: 4246884
    Abstract: A plate warmer having a heat storing core material for releasing heat to food serving supported thereon dishware over an extended period of time, i.e., in excess of thirty minutes, and a method of making said plate warmer. The heat storing material comprises beads of synthetic petroleum wax which are compressed to form a solid core having inwardly concave top and bottom surfaces and to expel air from the core. Top and bottom outer plate members are compressed to conform to the inwardly concave surfaces of the core and then sealed to define an airtight, waterproof cavity which is filled by the core. When the plate warmer is heated, the core expands outwardly against the concave walls of the outer plate members and the walls assume a substantially flat configuration wherein the cavity is enlarged to accommodate the expanded core material, the walls reassuming their inwardly concave configuration as the heat storing core material cools and releases heat through the top outer plate member to the dishware.
    Type: Grant
    Filed: August 17, 1979
    Date of Patent: January 27, 1981
    Assignee: McGraw-Edison Company
    Inventor: Edward B. Vandas
  • Patent number: 4245874
    Abstract: A flexible connector assembly for coupling, both mechanically and electrically, sections of electrical distribution track in a track lighting system includes first and second connector segments each having at a first end, a plug-in type tapping mechanism for joining the segments mechanically and electrically to sections of electrical distribution track. A flexible and expandible member formed of a pair of conductive, coiled, wire elements concentrically wrapped in opposite directions with respect to each other, is joined at opposite ends at the second ends, respectively, of the connector segments. The coiled wire elements define a tubular passageway for electrical conductors coupling the connector segments electrically and the member itself provides a ground connection between the connector segments and corresponding track sections.
    Type: Grant
    Filed: March 5, 1979
    Date of Patent: January 20, 1981
    Assignee: McGraw-Edison
    Inventor: Walter F. Bishop
  • Patent number: 4242570
    Abstract: An electric skillet or the like cooking vessel includes a cooking pan and a removably attachable insulative handle having a temperature control assembly with a spring loaded temperature sensing "shoe". One portion of the side wall of the pan defines a raised temperature sensing area against which the "shoe" is pressed upon joining the pan and handle. A lip extends from the raised area and forms a recess between the lip and sidewall of the pan. A first end of a torsion spring mounted on the handle for rotation is received in the recess for engagement with the lip subsequent to joining the handle and pan and rotating the spring to a first, locked position. The opposite end of the spring is received beneath a shoulder provided on the handle, thereby twisting the torsion spring to cause the first end thereof to forcibly engage the lip.
    Type: Grant
    Filed: September 8, 1978
    Date of Patent: December 30, 1980
    Assignee: McGraw-Edison Company
    Inventor: Robert H. Clark
  • Patent number: 4241373
    Abstract: A switchgear assembly which includes a vacuum interrupter, a current transformer, and a capacitive voltage sensor, all embedded within a cast epoxy housing mounted to a solidly grounded support structure. The voltage sensor includes a first capacitor, which is formed by an interrupter conductor stud, a plate, and the cast epoxy disposed therebetween, and a second capacitor, which is connected between the plate and a metal tube extending outside the housing. The tube is connected to ground through a conductive coating, applied to the housing, having an impedance which is very low in comparison to the impedance of the first capacitor.
    Type: Grant
    Filed: March 30, 1979
    Date of Patent: December 23, 1980
    Assignee: McGraw-Edison Company
    Inventors: Eugene G. Mara, John A. Schreiber, William N. LeCourt
  • Patent number: 4240122
    Abstract: A protective device for electrical power distribution equipment includes a removable fuse holder and an integral load switch. The protective device may be affixed to a grounded metal enclosure, such as an oil-filled transformer, into which the protective device extends. The fuse holder may be removed from the protective device for checking or replacement with a minimal opening into the enclosure into which the protective device extends. A suitable load switch actuator is provided for controlling current flow through a fuse in the fuse holder. This load switch actuator also provides an interlock arrangement to prevent removal of the fuse holder from, as well as insertion of the fuse holder into, the protective device unless the load switch is open, thus ensuring that interruption and initation of current flow through the fuse in the removable fuse holder is controlled by the load switch.
    Type: Grant
    Filed: March 26, 1979
    Date of Patent: December 16, 1980
    Assignee: McGraw-Edison Company
    Inventor: John E. Smith
  • Patent number: 4234526
    Abstract: An evaporative cooler having a one-piece, frameless shell secured to a bottom pan and having a top cover hinged along one edge to the side wall of the housing shell. A quick-release latching mechanism secures the top cover to the opposite side wall to hold the top cover closed while permitting the top cover to be easily opened for access to components of the evaporative cooler housed therein. Evaporative media pad assemblies have side frame members having V-shaped outer surfaces which slide in correspondingly shaped tracks in the corners of the shell to space the pad assemblies from the louvered side walls of the shell and permit the pad assemblies to be installed and removed from above with a vertical sliding movement.
    Type: Grant
    Filed: January 9, 1979
    Date of Patent: November 18, 1980
    Assignee: McGraw-Edison Company
    Inventors: Frederick G. Mackay, Spencer L. Mackay
  • Patent number: 4232361
    Abstract: An adjustable light fixture recessible in a ceiling for directing light at various angles includes a housing with a lamp assembly mounted therein. The lamp assembly comprises a reflector having a conventional bulb socket attached pivotally to a plate having spaced apertures. Resilient tracks, mounted at one end to the base of the housing are received in the apertures provided in the plate, rendering the plate slidable along such tracks. The tracks are each provided with a series of protrusions engagable with rollers each of which are mounted on the plate adjacent the spaced apertures to form a series of overcenter arrangements whereby the position of the plate and the lamp assembly may be adjusted. Stops are provided at the free end of each track to limit the movement of the lamp assembly therealong. However, the stops may be bypassed to permit complete removal of the lamp assembly from the housing.
    Type: Grant
    Filed: December 7, 1978
    Date of Patent: November 4, 1980
    Assignee: McGraw-Edison Company
    Inventor: Jeffrey C. Kelsall
  • Patent number: 4229782
    Abstract: A lighting unit comprising a lamp and a reflector provides high intensity, high efficiency, even illumination over an area of particular shape and size and has a cut-off angle which enables a person to approach close to the lighting unit without seeing the lamp or its reflection. The reflector comprises at least two spaced apart curved reflector surfaces which join each other along an edge line in a plane behind and spaced from the lamp. Points on the curve line of each reflector surface are spaced progressively further away from the lamp than the edge line. Some points on the curve are located on the side of the plane remote from the lamp. The lighting unit, which may employ reflector surfaces in addition to those above mentioned, may be employed in systems wherein it projects light upwardly for downward reflection from a ceiling or projects light downwardly directly onto a work surface.
    Type: Grant
    Filed: December 20, 1977
    Date of Patent: October 21, 1980
    Assignee: McGraw-Edison Company
    Inventors: Alan J. Ruud, Ian Lewin
  • Patent number: 4226325
    Abstract: Apparatus for continuously lubricating a conveyor belt with a mixture of water and soap or detergent during normal operation and for washing the conveyor belt during a preselected time interval after normal operation has ceased. Solenoid valves are interposed in water lines to a lubricating nozzle and wash nozzles to control the flow of water to the nozzles, and pumps are provided to inject soap or detergent into each of the water lines. During normal conveyor operation, electrical power is supplied only to the lubricating line solenoid valve and the lubricating line pump to produce a lubricating spray of water and soap or detergent from the lubricating nozzle which is directed onto the belt. When the master on-off switch is switched to the "off" position, a wash timer is actuated for a predetermined interval of time and cooperates with a relay to also enable the wash line solenoid valve and the wash line pump to deliver water and soap or detergent to the wash nozzle for cleansing the conveyor belt.
    Type: Grant
    Filed: March 15, 1979
    Date of Patent: October 7, 1980
    Assignee: McGraw-Edison Company
    Inventor: Edward B. Vandas
  • Patent number: 4223365
    Abstract: A trip indicator circuit for a circuit interrupter of an electric power system, which includes an electromagnetic status indicator, having an indicator which is movable between an indicating position and a non-indicating position, a pulse-actuated set coil for moving the indicator to the indicating position, and a pulse-actuated reset coil for moving the indicator to the non-indicating position. An indicator set circuit for energizing the set coil is connected across the trip coil by an electronic switching device which is rendered conductive by an overcurrent sensing circuit whenever a particular abnormal condition occurs in the electric power system, so that the set coil will be energized only when the circuit interrupter is tripped during the occurrence of the particular abnormal condition. A reset circuit is connected across the closing coil to energize the reset coil each time the circuit interrupter is closed.
    Type: Grant
    Filed: March 29, 1979
    Date of Patent: September 16, 1980
    Assignee: McGraw-Edison Company
    Inventor: Richard J. Moran
  • Patent number: 4217482
    Abstract: A control circuit useful in commercial cooking appliances, such as deep fat fryers, having electric heating elements and separate operating and safety controls including full power transmitting contactors for independently energizing and/or deenergizing the heating elements. The simplified control is economical, but reliable, and utilizes the safety control contactor connected in series power circuit with the heating elements and a single relay to establish both an on operating circuit for normal cooking conditions where the operating control cycles on and off to maintain the desired operating temperatures and a safety circuit that deenergizes all heating elements should an overheat condition occur and further that requires manual release or reset to again render the appliance operative.
    Type: Grant
    Filed: May 16, 1977
    Date of Patent: August 12, 1980
    Assignee: McGraw-Edison Company
    Inventor: Gurinder S. Wadia
  • Patent number: 4216370
    Abstract: An improved electric cooking appliance such as a hot plate, range or griddle, particularly for use in a commercial countertop application. This class of appliance has a case supporting an electric heating element and the space between the heating element and the bottom of the case is limited because of the height restrictions of the counter type appliance. The improved appliance has a baffle extending across the entire breadth of the case below the heating element and separating the case into the heating element compartment on the upper side of the baffle and the control compartment located on the lower side. The controls including a switch or the like are located in the lower compartment and thereby are separated from the heating element by this baffle. Both the heating element compartment and the control compartment are provided with openings in the case at opposite sides of the compartment to allow convective airflow cooling of the compartment.
    Type: Grant
    Filed: August 17, 1977
    Date of Patent: August 5, 1980
    Assignee: McGraw-Edison Company
    Inventor: Charles J. Charvat
  • Patent number: 4216372
    Abstract: A toaster chassis assembly for supporting heating element cards in an upstanding position in parallel relation, to define a bread-receiving slot therebetween, includes a horizontal base and end walls extending vertically upwardly from opposite ends of the base. The base defines a plurality of spaced slots for receiving tabs formed along the lower edges of the heating element cards for mounting the cards between the end walls and a plurality of tabular hooks extending from the base. Wire bread guards each comprising a plurality of vertical elements and an upper and lower horizontal element to form a grid, are mounted adjacent to the heating element cards to prevent engagement of bread slices being toasted with the heating element cards. The lower horizontal elements of the wire bread guards are received in the tabular hooks and the upper horizontal elements are received in slots formed along the upper edges of the end walls for supporting the bread guards.
    Type: Grant
    Filed: February 26, 1979
    Date of Patent: August 5, 1980
    Assignee: McGraw-Edison Company
    Inventor: Peter E. Huggler
  • Patent number: 4215267
    Abstract: A built-in well type food warmer includes a heating element assembly which is separably engaged with the underside of a food well by adjustable hanger members. The heating element assembly includes an upper heat distribution plate which is nestable within a recess formed in the bottom of the food well. The heating element assembly is enclosed by a tray member which is resiliently mounted within an enclosure. Brackets extending outwardly from the enclosure are attached to the lower ends of baffle hangers which extend downwardly from an upper rim of the food well. The hangers are formed of two separable members, adjustably connected together for selectively adjusting the length of the hanger. As the hangers are shortened, the heating element assembly is resiliently biased into contact with the bottom surface of the food well within a recessed portion thereof.
    Type: Grant
    Filed: July 19, 1978
    Date of Patent: July 29, 1980
    Assignee: McGraw-Edison Company
    Inventor: Johannes W. Kaebitzsch
  • Patent number: 4201124
    Abstract: A temperature sensitive timing control device for a toaster appliance includes a main bimetal element and a compensating bimetal element, both mounted on a support member mounted for pivotal movement in first and second directions, but biased toward the first direction. The main bimetal element includes a trigger arm normally engaging a latch release member to maintain the member in a set position. The latch release member when released by the trigger arm, in turn releases the bread carrier latch mechanism. The free end of the compensating bimetal element rests on a limiting screw which determines the extent of movement of the support member in the first direction. A locking member, operated by the toaster bread carrier when the latter is moved into a toasting position, engages the support member to secure it against movement in the first direction. When the bread carrier is moved to the toasting position, the bimetal elements are heated.
    Type: Grant
    Filed: February 27, 1978
    Date of Patent: May 6, 1980
    Assignee: McGraw-Edison Company
    Inventor: Peter E. Huggler
  • Patent number: 4200978
    Abstract: A grass trimmer includes a housing having a lower base wall from which extends a hub member of a predetermined height coupled to a motor encased in the housing, which motor drives the hub member rotatably. A cutting line element is attached to the hub member. A rim extends outwardly from the housing about the perimeter of the base wall. A first rim portion is of a height greater than the hub member and includes first and second spaced mounting ears extending therefrom toward the hub member. A protective shield designed for mounting on the housing in spaced relation from the base wall, is planar and of a similar shape to the base wall. The shield includes first and second tab and shoulder assemblies located for cooperation with the ears on the rim portion of the housing. Joining the last mentioned assemblies and respective ears attaches the shield to the trimmer housing.
    Type: Grant
    Filed: December 6, 1978
    Date of Patent: May 6, 1980
    Assignee: McGraw-Edison Company
    Inventors: Edward A. Irelan, Robert L. Bartlett, John W. Walch
  • Patent number: 4175483
    Abstract: A donut making appliance includes upper and lower electrically heated grids movable into and out of mating engagement along first surfaces. Each of the first surfaces of the grids includes a predeterminedly placed annular recess having a central core. Upon bringing the grids into engagement, the recesses are aligned to define a toroidally shaped cavity in which cake or the like batter is placed for baking donut shaped cakes. The central core of the lower grid defines a well preferably having the shape of a truncated cone, open at the first surface of the grid. The central core of the upper grid comprises a plunger having a shape complementary to that of the well and extending outwardly from the first surface of the grid, for receipt in the well upon engagement of the grids. The plunger-well arrangement ensures the alignment of the recesses and the displacement of cooking oil deposited in the well upon bringing the grids into engagement.
    Type: Grant
    Filed: May 18, 1978
    Date of Patent: November 27, 1979
    Assignee: McGraw-Edison Company
    Inventor: Robert H. Clark
  • Patent number: 4168872
    Abstract: A hollow rotatable shaft supported by bearing means surrounds a rivet extending through both ends thereof and rotatable therewith. A non-rotatable contact is connected to a terminal adjacent one end of the shaft and in brushing contact with one end of the rivet. A mechanical coupling is located at the opposite end of the shaft whereby the shaft, rivet and coupling are rotatable as a single unit and electrical current may pass through the rivet as the unit is rotating.
    Type: Grant
    Filed: July 21, 1978
    Date of Patent: September 25, 1979
    Assignee: McGraw-Edison Company
    Inventor: David P. Luckenbach