Patents Assigned to Ledex, Inc.
  • Patent number: 4660010
    Abstract: A rotary latching solenoid of the type in which a permanent magnet causes a flux flow path to be formed between opposing pole faces of an armature and a base in order to hold the armature in an energized or latched position is improved by providing the pole faces of the armature and base with raised sector portions, each sector portion having a sector face. In the energized or latched position, the sector faces of the armature and base are adjacent to each other and lines of flux flow between them are in a circumferential direction. The holding power of such an armature and base construction is greater than that of previous solenoids in which the opposing pole faces lie in a plane perpendicular to the solenoid axis.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: April 21, 1987
    Assignee: Ledex, Inc.
    Inventor: James E. Burton
  • Patent number: 4470030
    Abstract: Trip solenoids are disclosed in which a permanent magnet is positioned exteriorly of the armature case. In one version, a rotary solenoid has a permanent magnet between a ball race plate and the case and has a magnetic force sufficient to hold the rotary solenoid in its actuated position when the power is removed from the solenoid coil. An axial version of the trip solenoid is also disclosed.
    Type: Grant
    Filed: May 18, 1983
    Date of Patent: September 4, 1984
    Assignee: Ledex, Inc.
    Inventor: John L. Myers
  • Patent number: 4442418
    Abstract: An electric trip solenoid employs a pair of low-cost retaining or holding magnets in an open frame arrangement in which the magnets are positioned on opposite sides of the flat surfaces of a pole and in contact with the pole and the legs of an open frame. The magnets are thickness oriented so as to distribute their flux through relatively large areas avoiding regions of high flux density. In one embodiment the release point may be adjusted by rotating a screw in a closure plate to vary the reluctance of the secondary flux path therethrough.
    Type: Grant
    Filed: March 2, 1983
    Date of Patent: April 10, 1984
    Assignee: Ledex, Inc.
    Inventor: John L. Myers
  • Patent number: 4309582
    Abstract: In a controller of the type having a body, a pivot member within the body and an actuator shaft on the pivot member, a push button switch for the controller includes a handle fitted over an external end of the shaft and having a longitudinal opening therethrough, a push rod slidably positioned within the opening, a collar connected to the push rod, a switch operator which slidably engages the collar, and a switch positioned between the switch operator and the body such that, as the push rod is displaced toward the body, the push rod urges the collar to displace the switch operator toward the body thereby operating the switch. The switch operator preferably has an outer convex or arcuate bearing surface and an opening through which passes the actuator shaft. The sliding collar preferably has a lower concave portion which slidably engages the bearing surface of the switch operator, so that the push rod can actuate the switch at any given position of the controller.
    Type: Grant
    Filed: June 13, 1980
    Date of Patent: January 5, 1982
    Assignee: Ledex, Inc.
    Inventor: George T. Coors
  • Patent number: 4306206
    Abstract: A linear solenoid device includes a stator defining a cylindrical stator opening, and a pair of axially spaced cylindrical stator pole surfaces. An armature is mounted within the stator opening for movement parallel to the stator pole surfaces. The armature defines a pair of armature pole surfaces which overlap the stator pole surfaces by varying areas as the armature is moved. Annular air gaps are defined between the stator pole surfaces and the armature and the armature has mounted thereon a pair of cylindrical radially polarized permanent magnets, each such magnet being adjacent one of the armature pole surfaces. When a stator coil is energized, movement of the armature results from the varying reluctance across the air gaps as the armature pole surfaces overlap varying areas of the stator pole surfaces and, also, from repulsion of the permanent magnets. As a consequence, higher force outputs are attainable.
    Type: Grant
    Filed: June 9, 1980
    Date of Patent: December 15, 1981
    Assignee: Ledex, Inc.
    Inventor: John L. Myers
  • Patent number: 4306208
    Abstract: Mechanical lever controllers, also known as joy-stick type actuators, include a body within which is mounted a rod or lever for pivotal movement. The position of the rod is transmitted by an intermediate coupling or follower member to a differential transformer of the linear voltage differential transducer type (LVDT). The transducer includes an input coil and a pair of oppositely-positioned, axially-aligned output coils, and an armature moves within an armature cavity to vary the inductive coupling between the primary coil and the secondary coils. In one embodiment, two such differential transformers are offset at 90.degree. from each other to provide signals on the "X" and "Y" axes. In another embodiment, single axis output is measured in an actuator having a stackable housing.
    Type: Grant
    Filed: January 10, 1980
    Date of Patent: December 15, 1981
    Assignee: Ledex, Inc.
    Inventor: George T. Coors
  • Patent number: 4282501
    Abstract: An electromagnetic device includes a stator having first and second closed flux-carrying paths defined by first and second cores, each having a plurality of concentric cylindrical pole surfaces and each defining an air gap opening between the outermost of the pole surfaces and the second outermost of the pole surfaces, with each core having at least one further pole surface. Coils are provided for generating electromagnetic flux in the first and second closed flux-carrying paths with the direction of flux flow across the air gaps being substantially radial with respect to the cylindrical pole surfaces. An armature defines a first and a second plurality of concentric cylindrical armature surfaces. The armature is mounted to be movable in a direction substantially parallel to the pole surfaces with each of the first and second cylindrical armature surfaces overlapping a corresponding one of the concentric cylindrical pole surfaces by an area dependent upon the position of the armature.
    Type: Grant
    Filed: August 23, 1979
    Date of Patent: August 4, 1981
    Assignee: Ledex, Inc.
    Inventor: John L. Myers
  • Patent number: 4272748
    Abstract: A high speed axial-type printing solenoid includes a rebound and energy absorbing arrangement which employs a block of energy-absorbing "dead" elastomeric material held in a partially compressed state by an impact plate. The impact plate is mounted to engage and position the plunger or armature at a rest position and to transmit impact forces to the partially compressed block of elastomeric material.
    Type: Grant
    Filed: January 30, 1980
    Date of Patent: June 9, 1981
    Assignee: Ledex, Inc.
    Inventors: Philip E. Fugate, Kenneth L. Roy
  • Patent number: 4235114
    Abstract: A testing device for applying a force to a material test sample includes a test fixture for engaging the test sample and a solenoid, operatively coupled to the test fixture, for applying a predetermined force to the test sample in response to a solenoid control signal. A strain gauge is mounted on the test fixture and provides an electrical output indicative of the force applied to the test sample. A force setting circuit provides an electrical output indicative of the predetermined force which is to be applied to the test sample. A solenoid control circuit is responsive to the output from the strain gauge element and to the output of the force setting element and provides a control signal to the solenoid such that the predetermined force may be applied to the test sample. The force setting circuit provides an electrical output having an adjustable rate of increase and an adjustable maximum level. A sample circuit monitors the output of the strain gauge to store the peak force applied to the test sample.
    Type: Grant
    Filed: April 2, 1979
    Date of Patent: November 25, 1980
    Assignee: Ledex, Inc.
    Inventor: David B. Mohler
  • Patent number: 4217567
    Abstract: Low cost tubular solenoids are formed with a drawn case in which the pole portion forming the base of the solenoid is defined as an integral inwardly extending part of the case. A coil bobbin is formed by the injection molding of plastic material and is provided with an integral wall which is positioned in abutting relation to the inside surface of the pole portion, thereby forming a stop surface for the solenoid plunger and effectively spacing the plunger from the base. The plunger is guided on the internal surfaces of the bobbin and in one embodiment, a spun hollow sheet metal bushing is captured by the case in telescopic relation to the bobbin, and is formed with threads which receive thereon a sheet metal retaining nut. In another embodiment of the invention, a washer is threaded onto an axial extension portion of the bobbin, and the open end of the case is crimped onto an annular groove formed on the washer. In a further embodiment, the washer is injected molded in place on the bobbin.
    Type: Grant
    Filed: September 18, 1978
    Date of Patent: August 12, 1980
    Assignee: Ledex, Inc.
    Inventors: Kenneth L. Roy, William D. Sadgebury
  • Patent number: 4200401
    Abstract: A print wire solenoid for high-speed operation is made with two major components or subassemblies. The first is a plastic injected unitary bobbin or stator assembly which incorporates a core ring and a core, and a stator which forms a bobbin for receiving an electric coil. The parts in the stator are positioned and molded to a datum surface. The second major subcomponent is a unitary armature assembly which incorporates an armature, a retraction spring, and a print wire, all anchored to a plastic body. These parts are likewise positioned with respect to a datum surface. The stator assembly and armature assembly are retained within a drawn metal case, and a rebound disc is positioned within the case and locates the datum surface of the armature assembly in the same plane as the datum surface of the stator assembly so as to define an accurate working air gap.
    Type: Grant
    Filed: May 22, 1978
    Date of Patent: April 29, 1980
    Assignee: Ledex, Inc.
    Inventors: Kenneth L. Roy, Philip E. Fugate
  • Patent number: 4157521
    Abstract: A rotary solenoid has a substantially constant clearance air gap, adapted to proportional operation, includes a generally cup-shaped case of ferromagnetic material, an energizing coil is received in the case adjacent, an annular stator member is received in the open end of said case adjacent said coil and has at least one arcuately formed pole member, an armature has sector-shaped poles corresponding in arcuate spacing and in number to the stator poles, a plate is carried on one end of said armature and defines with the case at least one pair of cooperating non-inclined, arcuately-extending ball bearing recesses, and can conveniently define the extent of rotation of said armature.
    Type: Grant
    Filed: January 26, 1978
    Date of Patent: June 5, 1979
    Assignee: Ledex, Inc.
    Inventor: Gerald H. Leland
  • Patent number: 4153890
    Abstract: Wet and dry plunger solenoids are formed with a three-piece spool assembly including a base and a hub joined by a non-magnetic sleeve. An electric coil is wound directly onto the sleeve to compress the sleeve about the telescopically interfitted base and hub parts to form a fluid-tight joint. In a wet plunger solenoid the armature or plunger cavity has high resistance to deformation when fluid pressure is applied to the interior, and a fluid-tight joint is formed which is free of threaded connections and is reinforced by reason of the fact that the coil is wound in tension. The cumulative compression effectively joins the parts into a unitary structure. Also, a highly efficient low cost construction is provided for use in a dry solenoid.
    Type: Grant
    Filed: August 18, 1977
    Date of Patent: May 8, 1979
    Assignee: Ledex, Inc.
    Inventor: George T. Coors
  • Patent number: 4135150
    Abstract: A decoder circuit for receiving a sequence of coded digit signals and detecting when a preselected digit signal sequence is received includes a converter having a plurality of converter outputs which are energized in response to receipt of each of the coded digit signals. A plurality of digit sequence selection lines are connected to predetermined ones of the converter outputs in dependence upon the preselected digit signal sequence. A plurality of coincidence gates are provided with each of the gates responsive to one of the digit sequence selection lines. A shift register provides a means for enabling each of the coincidence gates in a sequence which corresponds to the predetermined digit sequence. The outputs of the coincidence gates are applied to the shift register shift input to cause the register to shift and enable the next gate in succession. Means are provided for detecting when each of the coincidence gates associated with the preselected digit selection lines has provided an output pulse.
    Type: Grant
    Filed: August 12, 1977
    Date of Patent: January 16, 1979
    Assignee: Ledex, Inc.
    Inventor: Larry L. Quigley
  • Patent number: 4097833
    Abstract: An electromagnetic device includes a stator having a first closed flux carrying path including a core and an air gap opening in the core. Flux is generated in the flux carrying path by a coil, with the direction of flux flow across the air gap being perpendicular to pole surfaces defining the air gap. An armature is mounted to be movable between the pole surfaces and to overlap varying areas of the pole surfaces in dependence upon the position of the armature. The overlap areas are directly proportional to the position of the armature. In one embodiment a bi-directional device having two such closed flux carrying path simultaneously acts on a single armature. The equilibrium position of the armature is dependent on the relative flux flow through the two flux carrying paths. A further embodiment is disclosed in which an air gap opening is inclined to the direction of flux flow in the core of the flux path. The area of each pole surface defining the inclined air gap exceeds the cross-sectional area of the core.
    Type: Grant
    Filed: February 9, 1976
    Date of Patent: June 27, 1978
    Assignee: Ledex, Inc.
    Inventor: John L. Myers
  • Patent number: 4044324
    Abstract: A wet plunger solenoid is formed with a three-piece spool assembly including a base and a hub joined by a nonmagnetic sleeve. An electric coil is wound directly onto the sleeve to compress the sleeve about the telescopically interfitted base and hub parts to form a fluid-tight joint, thus forming an armature or plunger cavity which has high resistance to deformation when fluid pressure is applied to the interior. A fluid-tight joint is formed which is free of threaded connections and is reinforced by reason of the fact that the coil is wound in tension, and the cumulative compression effectively joins the parts into a unitary structure.
    Type: Grant
    Filed: April 30, 1976
    Date of Patent: August 23, 1977
    Assignee: Ledex, Inc.
    Inventor: George Thom. Coors
  • Patent number: 3970981
    Abstract: A solenoid includes a base formed with an external taper and an adjacent hub sleeve also formed with an external taper, the base and hub being joined by an alignment piece of non-magnetic material formed with a pair of internal tapers which are proportioned to mate with the external tapers of the hub and the base. The alignment insert assures and maintains a predetermined concentric coaxial alignment of the hub and base with respect to a common movable armature.
    Type: Grant
    Filed: May 8, 1975
    Date of Patent: July 20, 1976
    Assignee: Ledex, Inc.
    Inventor: George T. Coors
  • Patent number: RE31813
    Abstract: A high speed axial-type printing solenoid includes a rebound and energy absorbing arrangement which employs a block of energy-absorbing "dead" elastomeric material held in a partially compressed state by an impact plate. The impact plate is mounted to engage and position the plunger or armature at a rest position and to transmit impact forces to the partially compressed block of elastomeric material.
    Type: Grant
    Filed: June 8, 1983
    Date of Patent: January 22, 1985
    Assignee: Ledex, Inc.
    Inventors: Philip E. Fugate, Kenneth L. Roy