Prestressing Rod, Filament Or Strand Patents (Class 29/452)
  • Patent number: 4074731
    Abstract: A wire mesh structure, primarily for space applications, characterized by its lightweight, its compact stowage and deployment capability, and its ability to maintain its shape under widely varying thermal conditions. The structure has a frame supporting a wire mesh including wires which are terminally secured to the frame and constitute the primary structural elements of the mesh. These structural wires are preformed to a spring-like configuration which renders the wires resiliently compliant with a low spring rate in the endwise direction and are stretched to produce a predetermined tension preload in the wires when the mesh is installed on the supporting frame. This preload retains the mesh in a taut condition under widely varying thermal conditions and thereby prevents the formation of slack in the mesh which would allow out-of-plane displacement of the mesh.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: February 21, 1978
    Assignee: TRW Inc.
    Inventor: John S. Archer
  • Patent number: 4056882
    Abstract: This invention describes a method of making a commutator, for a high speed electric machine, (1) embedding a number of conductive bars in insulating plastics material to form a moulded commutator (2) the moulded commutator defining at least one annular seat (3) placing a ring of high tensile material on the seat whereby to stress the ring in tension and thereby apply a radially inward load to each bar which is greater than the centrifugal force on the bar at maximum running speed. The invention also includes a commutator made by this method.
    Type: Grant
    Filed: June 7, 1976
    Date of Patent: November 8, 1977
    Assignee: Airscrew Howden Limited
    Inventor: Robert Arthur Letts
  • Patent number: 4057687
    Abstract: Structure intended to transmit great mechanical stresses, comprising an elongated core comprising at least an agglomerated glass fibre rod and fixing armatures fitted to the ends of the core, comprising means exerting radial compression stresses or stresses tending to jam the rod and maintaining at least partly those efforts in a zone of the structure situated in the armatures, even when the structure is not subjected to mechanical stresses. The structure has application to insulators for electric apparatus, stays, suspension of electric power conveying lines.FIELD OF THE INVENTIONThe present invention concerns a structure intended for transmitting great mechanical stresses, comprising an elongated core comprising at least one rod of agglomerated glasse fibres and fixing armatures fitted to the ends of the core, by means of which the mechanical efforts are transmitted. It relates more particularly to an improvement in the connection between core and armature of such structures.
    Type: Grant
    Filed: November 12, 1975
    Date of Patent: November 8, 1977
    Assignee: Ceraver
    Inventor: Michel Willem
  • Patent number: 4054987
    Abstract: The disclosure is of a novel method for constructing a recreational ball-playing court surface from a plurality of square, unitary, elastic, molded thermoplastic sheets having a plurality of support legs and means for interlocking the sheets together. The sheets are divided into square gratings. The method of the invention comprises assembling the sheets together under tension along the horizontal axes of the sheets. The construction of the court surface according to the method of the invention obviates buckling of the surface due to thermal expansion of the sheets.
    Type: Grant
    Filed: February 26, 1976
    Date of Patent: October 25, 1977
    Assignee: Mateflex/Mele Corporation
    Inventor: Nicholas G. Forlenza
  • Patent number: 4053974
    Abstract: A tendon anchorage for use in prestressing concrete members is disclosed which preferably includes a tubular mounting means mounted to extend over the tendon and through an opening in a bearing or anchor plate in order to secure the bearing plate in fixed and aligned relation to a tendon for casting the bearing plate into the concrete member in a predetermined orientation therein. Spacing means between the form board and the anchor plate allow the anchor plate to be cast into a recess in the concrete member. A wedge receiving housing and wedge assembly is positioned in alignment and in abutting relation with the bearing plate after casting of the bearing plate into the concrete.
    Type: Grant
    Filed: January 30, 1976
    Date of Patent: October 18, 1977
    Assignee: Conenco International Limited
    Inventors: George H. Howlett, James W. Howlett
  • Patent number: 4051216
    Abstract: A method of moulding concrete ties or other similar articles having pre-stressed reinforcing wires or rods therein, wherein a series of open ended multi-cavity moulds of similar cross-sectional shape are aligned end to end in groups, wires are positioned in the aligned cavities of the moulds and are tensioned, the wires are separated from one another and into horizontal rows in each group by flat sided bar like spacers which are interposed between the ends of adjacent moulds of that group, while the groups themselves are separated by vertically movable spacer plates each having vertically extended slots which arrange the wires into vertical rows.
    Type: Grant
    Filed: December 4, 1974
    Date of Patent: September 27, 1977
    Assignee: Concrete Industries (Monier) Limited
    Inventor: Robert Lyndon Bratchell
  • Patent number: 4048706
    Abstract: Reinforcing members of concrete structures are often tensioned against a considerable frictional resistance, which causes an uneven stress distribution along the member. This means that the reinforcing capacity of the member is unsatisfactorily utilized. To obtain a more even stress distribution the tensioning operation is terminated by a sudden, measured release of tensioning force, resulting in a shock wave progressing along the member.
    Type: Grant
    Filed: February 3, 1976
    Date of Patent: September 20, 1977
    Inventor: Birger Ludvigson
  • Patent number: 4035858
    Abstract: A method for manufacturing bolts of a given grade and size in which, after forming, threading and heat treating, each bolt is work hardened by the application and subsequent removal of a tensile force of magnitude somewhat above the minimum proof load for the given grade and size of bolt, so that all bolts so treated will have the same yield point and the torque rotation curve for each bolt will have a discontinuity in slope at this common yield point.
    Type: Grant
    Filed: March 8, 1976
    Date of Patent: July 19, 1977
    Inventor: Norman C. Dahl
  • Patent number: 4006523
    Abstract: A method of producing a prestressed beam of steel or steel and concrete having at least one flange in which a plurality of spaced apart transmission elements arranged symmetrically with respect to the center of the span of the beam are secured to the flange, tensioning wires are attached to each two symmetrically disposed transmission elements with the wires extending at predetermined distances from the flange, tensioning the wires to apply to the beam, via the transmission elements, on the one hand solely compressive forces and, on the other hand, in positions corresponding to each transmission element, a bending moment which is opposite to that of the loads to be applied in use, and applying a stress to the beam during the tensioning of the wires substantially to counteract the bending moments. At least one guide element for the wires may be disposed between two symmetrically disposed transmission elements to prevent lateral buckling of the beam during tensioning of the wires.
    Type: Grant
    Filed: January 21, 1975
    Date of Patent: February 8, 1977
    Inventor: Jean-Baptiste Mauquoy
  • Patent number: 3999278
    Abstract: A method for assembling a wiper blade with a wiper arm wherein the wiper blade consists of a backing strip having keyhole-shaped slots therein and an open aperture at one end of the strip, along with a multifarious wiping element having a plurality of T-shaped projections for fitting in the keyhole-shaped slots in the backing strip and a projection at the end thereof for buttoning the backing strip to the wiping element upon stretching the wiping element. The steps of the method define the sequence of steps of aligning the projections with the slots and stretching the wiping element to align the projection with the open aperture whereupon release of the stretched wiping element completes the assembly.
    Type: Grant
    Filed: January 15, 1976
    Date of Patent: December 28, 1976
    Assignee: The Anderson Company
    Inventor: Lawrence R. Loskill
  • Patent number: 3975815
    Abstract: This invention relates to a method of inserting tension wires in the process of wire assembling for a concrete pole or pile characterized in that forward ends of a required number of tension wires are clamped together by a chuck, and the chuck is inserted from one end of a wire cage to the other end and interiorly thereof, so that a number of tension wires can be inserted into the wire cage at one time.
    Type: Grant
    Filed: December 30, 1974
    Date of Patent: August 24, 1976
    Assignee: Nippon Concrete Industries Co. Ltd.
    Inventor: Takemitsu Mori
  • Patent number: 3972110
    Abstract: A one-piece spring fastener is provided for mounting fencing wire or the like to a channel shaped support. In one embodiment the wire is mounted generally perpendicularly to the support and is free to move along its axis relative to the support. The fastener is of a generally "U" shape in cross-section comprising two generally parallel, spaced apart, generally "T" shaped members joined along substantially the entire tops thereof by a bight or interconnecting bridge portion. The top portions of the "T" shaped members in combination with the bight portion form a trough for receipt of the wire and the base portions of the "T" shaped members are generally dart shaped for nonrotational, forced receipt inbetween and retention by the inturned flanges of the channel shaped support.
    Type: Grant
    Filed: May 27, 1975
    Date of Patent: August 3, 1976
    Assignee: Eaton Corporation
    Inventor: John J. Sasena
  • Patent number: 3969812
    Abstract: A pressure vessel of the type wherein a metallic liner in the shape of a cylindrical portion with a dome-shaped portion at each end thereof is overwrapped by a plurality of layers of resin coated, single fiberglass filaments. A four-step wrapping technique reinforces the vessel with overwrap material at the most likely areas for vessel failure. Overwrapping of the vessel is followed by a sizing pressurization cycle which induces a compressive prestress into the liner and thereby permits the liner to deform elastically through an increased strain range.
    Type: Grant
    Filed: April 19, 1974
    Date of Patent: July 20, 1976
    Assignee: Martin Marietta Corporation
    Inventor: Emory J. Beck
  • Patent number: 3965564
    Abstract: The specification and drawings disclose a multiple latch assembly particularly suited for use in contoured vehicle doors. The disclosed assembly includes a plurality of latch members each having an outwardly biased latch pin. Operatively connected to all of the latch pins is a common operating assembly including a case defining a cavity and a handle pivotally mounted between the sides of the cavity. A slide member is carried on the case and interconnects with the handle so that oscillation of the handle produces reciprocation of the slide member. Lengths of flexible actuating cable are connected between the slide member and each of the latch pins. Each length of cable is arranged so that movement of the slide member in one direction will produce simultaneous inward movement of all latch pins.
    Type: Grant
    Filed: March 24, 1975
    Date of Patent: June 29, 1976
    Assignee: Cleveland Hardware & Forging Co.
    Inventor: Mike J. Slovensky, Jr.
  • Patent number: 3964154
    Abstract: In a device for simultaneously stressing a group of tension elements in a prestressed concrete member, a common driving source is used for mechanically rotating each of the spindles and wrench sleeves which are connectible to the tension elements. Separate safety clutches are selectively engageable with each of the spindles and wrench sleeves so that individual connection of each spindle to a tension element can be provided and, as the element is stressed in tension, individual adjustment can be provided by the wrench sleeve for each anchor nut on its associated tension element.
    Type: Grant
    Filed: June 30, 1975
    Date of Patent: June 22, 1976
    Assignee: Dyckerhoff & Widmann Aktiengesellschaft
    Inventor: Peter Auer
  • Patent number: 3960995
    Abstract: Thermal prestressing methods using unit and selective heating of tendons incorporated in a ceramic or cermet body to selectively elongate the tendon with respect to the body and soften the latter. Upon cooling an anchorage bond is formed between the body and the ends of the tendons, which bond develops a tension in the tendon and prestress in the body upon further cooling. Bodies are also prestressed by forming a bond between the tendon and the body and then heating the body in use so as to elongate the tendon relative to the body, the tendon having a greater coefficient of expansion than the material of the body.
    Type: Grant
    Filed: April 17, 1972
    Date of Patent: June 1, 1976
    Inventor: Jacques P. Kourkene
  • Patent number: 3950840
    Abstract: A method for anchoring a ring tensioning member in a circular container, especially a concrete tank or a concrete tube is characterized by cutting out at least one recess in the wall thickness of said container for locating therein a hemispherical anchorage body in overhung position having on its circumference at least one slot and through bores for a bracing cable. The bracing cable which has been inserted in the wall of said container and prestressed by a stretching mechanism will be anchored in said anchorage body, whereafter the recess will be covered in such a way as to be in alignment with the surface of said container.
    Type: Grant
    Filed: November 21, 1973
    Date of Patent: April 20, 1976
    Assignee: Losinger AG
    Inventor: Hans Dietrich
  • Patent number: 3944242
    Abstract: A new supporting structure for a mobile home comprising pre-stressed concrete and a method for making same. The supporting structure comprises a rectangular floor, supported by beams on the lower surface of the floor. A pair of large longitudinal beams are formed on the lower surface of the floor adjacent the longitudinal edge of the floor. A plurality of smaller transverse beams are formed on the lower surface of the floor connecting the longitudinal beams. Both the longitudinal and transverse beams are pre-stressed. Means for attaching wheels and a towing hitch are provided. The supporting structure is cast in a single piece in a bed provided with channels for the longitudinal and transverse beams. The beams are pre-stressed in a conventional manner either by pre-tensioning or post-tensioning tendons. After the concrete has set and the tendons anchored, the supporting structure is lifted out, and wheels and a towing hitch attached.
    Type: Grant
    Filed: November 8, 1974
    Date of Patent: March 16, 1976
    Inventor: Marcus P. Eubank
  • Patent number: 3942238
    Abstract: A method of reinforcing structures by means of tensioned steel cables is disclosed. A hollow conduit or duct is positioned in the structure and secured therein and made a part thereof by pouring concrete in a form surrounding the conduit. A specified number of steel strands, wires or cables are inserted and pushed through the conduit one-by-one by a mechanical strand pusher. A nose guide is positioned on the end of each of the strands if required to enable them to pass easily through the conduit. When the required amount of strands are positioned in the conduit and the concrete has set to a predetermined strength, the strands are stressed thereby putting the structure under compression.
    Type: Grant
    Filed: April 22, 1974
    Date of Patent: March 9, 1976
    Inventor: Jean Pierre Dore