US2615678A - Clamping device - Google Patents

Clamping device Download PDF

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Publication number
US2615678A
US2615678A US185659A US18565950A US2615678A US 2615678 A US2615678 A US 2615678A US 185659 A US185659 A US 185659A US 18565950 A US18565950 A US 18565950A US 2615678 A US2615678 A US 2615678A
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US
United States
Prior art keywords
concrete
tensioning
wire
wires
mold
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US185659A
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English (en)
Inventor
Dudley H Stent
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STENT PRECAST CONCRETE Ltd
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STENT PRECAST CONCRETE Ltd
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Publication of US2615678A publication Critical patent/US2615678A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
    • B28B23/02—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members
    • B28B23/04—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members the elements being stressed
    • B28B23/043—Wire anchoring or tensioning means for the reinforcements
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/08—Members specially adapted to be used in prestressed constructions
    • E04C5/12—Anchoring devices
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
    • E04G21/12—Mounting of reinforcing inserts; Prestressing

Definitions

  • This. invention relates to a clamping device particularly adapted for use in applying tension to wires, rods and the like in the molding of pre- '.
  • a clamping device particularly adapted for use in applying tension to wires, rods and the like in the molding of pre- '.
  • rigid transverse devices such as'bars, situated at the two ends of the concrete, the reinforcements being stretched by increasing the distance between the'two transverse devices.
  • one or both end portions of a stretched Wire or rod reinforcement for a pro-stressed concrete article and enwrapping a rigid transverse member is clamped between such enwrapped member and a surface on means stretching the reinforcement.
  • the means which stretches or maintains the reinforcement stretched nips the end portion of. thereinforcement and precludes the latter slippingand unwrapping off the transverse member.
  • a reinforcement wire formed into a loop enwraps the outwardly directed convex surface of a stout transverse cleat bar of halfround cross section located within one or both ends of the mold for the concrete, the wire, for instance, extending threetimes between the two transverse bars and terminating at each.
  • Each end portion of the wire after enwrapping the convex surface of the respective transverse bar, extends between the inwardly directed flat surface of the respective. transverse bar and a washer or plate behind a nut on the stem of a bolt extending freely through the transverse bar-and the respective end of the mold.
  • Tension maintained on the wire by the bolts at both ends of the mold alsoclamps the ends of the wire between the respective washers or plates and the respective transverse bars.
  • apparatus -aijoint comprising an element for receiving tension, a tensioning member and a clamping part, wherein the element is wrapped about a first surfaceof the tensioning member and then is clamped against a second surface of the member by the clamping part, the clamping action being transmitted through the-member by the actual 'tensioning force.
  • Another object is to provide a joint for simultaneously pro-stressing two or more reinforcing rods, in which the joint includes a cylindrical bolt passed through a hole in the tensioning member and clampin part, the hole being tapered in the direction of the tension force.
  • This arrangement permits rocking of the tensioning member, thereby compensating for unequal dimensions of the two reinforcing rods.
  • Another object of the invention is to provide a device for simultaneously gripping and applying a tensioning force to at least one elongated element
  • a tensioning member having a first surface of substantial area facing in the direction of the tensioning force for engaging a first portion of .each said elongated element. and having a second oppositely facing surface of substantial area for engaging a second portion of said elongated element, a clamping part located in proximity to said second surface and in contact with. said second portion, and means for exerting tensioning force on said clamping part to compress said second portion between said part and .said member while simultaneously applying tensioning force to the first portion of said elongated elementthrough the first surface of said member.
  • Still another'object of the invention is to provide a device for simultaneously gripping and applying a tensioning force to at least one elongated element
  • a tensioning member about which said element is enwrapped, said member having a first surface area facing in the direction of the tensioning force for engaging a first portion of each said elongated element, and having a second oppositely facing surface of substantial area for engaging asecond portion of said elongated element, said element passing firstabout saidfirst surface and then along said second surface, a clamping part located in proxmember while simultaneously applying tension- ;ing forceto the first portion-of. said;v elongated elementthrough the first surface of said member.
  • a further object is to provide a joint for securing and applying tension to rods which are positioned asymmetrically on the tensioning member without causing bending movements in the joint.
  • Fig. 1 is a broken longitudinal section of a mold for concrete provided with means for stretching longitudinal reinforcements for the concrete, and
  • Fig. 2 is a corresponding plan.
  • Fig. 3 is a view similar to Fig. 1 but showing a modification.
  • Fig. 4 is a longitudinal section of an end of a mold showing a modification.
  • Figs. 5 and 6 are longitudinal sections on a larger scale of alternative clamping devices for the wire reinforcement.
  • a is a mold, for concrete which is to be compressively pre-stressed, by embedding wires b, which are maintained stretched in the mold a whilst the concrete is setting.
  • transverse cleat bars 0 of half-round cross section located one at each end of the mold and drawn apart so as to stretch the wires b extending between them.
  • the transverse bars 0 are each mounted on a longitudinal bolt d extending freely therethrough and through the respective end wall a of the mold a.
  • the wires b are stretched by hydraulic rams e thrusting against a crosshead f through which the bolts (1 at one end of the mold extend to terminate with heads 11 on the outer face of the crosshead I.
  • the tension on the wires b is maintained by tightening up nuts 0 on the bolts d.
  • each wire b enwrapping a bar 0 is clamped between the latter and a washer plate h, interposed between the flat surface of the respective bar 0, and a nut i on the bolt 11 and transmitting to the wires b the tension applied by the bolt 11.
  • each wire b extends three times between the two ends of the mold, so that of each wire b there are two lengths above the bolts d and one length beneath, and also the ends of each wire b are at opposite ends of the mold a.
  • the bolts d are set so as to extend through the cross bars 0 nearer to the double lengths of wire than to the single length of wire.
  • the cross bars 0 instead of being of half-round cross section, may be of crescent or semi-tubular cross section and the washer plate It may be of half-round cross section, the end of the wire 17 being clamped between the opposed rounded concave surface of the cross bar 0 and the convex surface of the washer plate h.
  • the wires b to be stretched are pre-bent to the looped shape necessary to fit on and between the cross bars 0, and with the aid of a suitable jig can all usually be bent to the same length with only a very slight probable difference between all the wires of a set.
  • the holes for the bolts in the cross bars 0 are tapered inwardly towards the nuts 1 as shown in Figs. 5 and 6, so that the cross bars 0 are capable of rocking.
  • the washer plates it may bend in exerting the clamping action on the ends of the wires b.
  • the surface of the cross bars c can be grooved to take both of the two wire ends on convergent surfaces of the groove and projecting from the groove 7', as shown in Fig. 5.
  • the two wire ends b will automatically mutually displace one another so as to be equally clamped notwithstanding any bending of the washer plate 71..
  • the bolts d are unscrewed from the nuts 2 and removed.
  • the holes thereby left in the concrete can be plugged with wet concrete.
  • transverse bar in the drawings can be developed into other shapes.
  • the bar may be a ring.
  • the wire stretching arrangement consisting of the bars 0 and bolts d shall be located within the mold. They can be located outside the ends of the mold. In such case the wires are cut at the ends of the set concrete.
  • one or more pre-cast concrete units may be inserted between the anchoring devices and strut them apart on partial release of the stretched reinforce ment, the pre-formed concrete strut bearing against and causing the washer plate still to nip the wire reinforcement.
  • Such pre-formed concrete struts may be more or less tubular and more or less surround the stretched reinforcements.
  • the struts are inserted dry and may be amplified by added wet concrete or grouting embedding the stretched reinforcements.
  • the concrete units may be arranged so that when the concrete has set or, if pre-cast, when in position, straining bolts and nuts can be recovered. Cavities thus exposed can be plugged with wet concrete.
  • the invention is equally pplicable to concrete units which are pre-stressed by means of high tensile steel subjected to an initial tension substantially greater than or equal to the elastic limit of normal mild steel, or to concrete units which are pre-stressed by means of ordinary mild steel.
  • joint and the clamping and tensioning device have numerous applications outside of the molding of prestressed concrete objects.
  • a device for simultaneously gripping and applying a tensioning force to at least one elongated element comprising a tensioning member having a first surface of substantial area facing in the direction of the tensioning force for engaging a first portion of each said elongated element and having a second oppositely facing surface of substantial area for engaging a second portion of said elongated element, a clamping part located in proximity to said second surface for contact with said second portion, and means for exerting tensioning force on said clamping part to compress said second portion between said part and said member While simultaneously applying tensioning force to the first portion of said elongated element through the first surface of said member.
  • a device for simultaneously gripping and applying a tensioning force to at least one elongated element comprising a tensioning member about which said element is enwrapped, said member having a first surface area facing in the direction of the tensioning force for engaging a first portion of each said elongated element and having a second oppositely facing surface of substantial area for engaging a second portion of said elongated element, said element passing first about said first surface and then along said second surface, a clamping part located in proximity to said second surface and in contact with said second portion, and means for exerting tensioning force on said clamping part to compress said second portion between said part and said member while simultaneously applying tensioning force to the first portion of said elongated element through the first surface of said member.
  • a device said member and said part having matching openings therein, said second surface of said member including two areas located on opposite sides of the opening in said tensioning member, said means for exerting tensioning force consisting of a cylindrical force transmitting member passing through said openings and means carried by said cylindrical member for engaging and transmitting force to said clamping part, the walls of the opening in said tensioning member being diverging in the direction of application of the tensioning force to permit rocking of said tensioning member to compensate for small differences in the dimensions of the elements in contact with said second portion of said member.
  • a device in which the two areas forming said second surface of the tensioning member comprise grooves having tapering walls.
  • said means for exerting tensioning force consisting of a cylindrical force transmitting member passing through said openings and means carried by said cylindrical member for engaging and transmitting force to said part.
  • a device there being a plurality of said elongated elements disposed unsymmetrically with regard to said member so as to apply an unbalanced load to said member, said matching openings and said cylindrical member being located off center with respect to said tensioning member in the direction of the greatest load on said member.
  • a device in which said member is arcuate in cross section, the outer convexly curved surface forming said first surface and the inner concavely curved surface forming said second surface, said clamping part having a surface configuration matching said inner surface, said member and said part having matched openings therein, said means for exerting tensioning force consisting of a cylindrical force transmitting member passing through said openings and means carried by said cylindrical member for engaging and transmitting force to said part.
  • a novel device for simultaneously gripping and applying tensioning force to such elongated element comprising a tensioning member having a first and convex surface of substantial area facing in the direction of the tensioning force for engagement by a first portion of said element spaced from the end of the element, and having a second surface of substantia1 area facing oppositely to said first surface for engagement by a second portion of element nearer the end thereof than said first portion, thereby providing enwrapping of the element about said member, a clamping part having a surface of a configuration similar to that of said second surface, and tensioning means engaging said clamping part to pull said clamping part toward the second surface of said member to clamp said second portion of said elongated element between said member and said clamping part while simultaneously urging said member in the direction of the tensioning force to apply tension to said element through said first surface.

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
  • Reinforcement Elements For Buildings (AREA)
US185659A 1943-10-13 1950-09-19 Clamping device Expired - Lifetime US2615678A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2615678X 1943-10-13

Publications (1)

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US2615678A true US2615678A (en) 1952-10-28

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Application Number Title Priority Date Filing Date
US185659A Expired - Lifetime US2615678A (en) 1943-10-13 1950-09-19 Clamping device

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US (1) US2615678A (enrdf_load_stackoverflow)
BE (1) BE491207A (enrdf_load_stackoverflow)
CH (1) CH271051A (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2763464A (en) * 1952-07-26 1956-09-18 Leonhardt Fritz Apparatus for anchorage of concrete reinforcements
US3126671A (en) * 1964-03-31 Method of prefabricating the block
DE1186700B (de) * 1958-05-20 1965-02-04 Internat Pipe And Ceramics Cor Betonrohr mit vorgespannten Bewehrungsringen in der Naehe der Rohrenden
US3341176A (en) * 1964-01-22 1967-09-12 Baltimore Concrete Plank Corp Apparatus for imparting tension to a reinforcing cable of u-shaped configuration
US3399434A (en) * 1965-09-27 1968-09-03 William F. Kelly Anchors for stressed cables
US3774359A (en) * 1971-03-15 1973-11-27 B Kahn Reinforced concrete plate construction
US4313287A (en) * 1980-01-25 1982-02-02 Romig Jr Byron A Internally tensioned structural member and method of assembling same
US4398377A (en) * 1980-01-25 1983-08-16 Romig Jr Byron A Structural member with equalized internal tension
US4537388A (en) * 1982-05-14 1985-08-27 Mccabe Francis B Adjustable tensioning device
US4683632A (en) * 1985-09-09 1987-08-04 Caterpillar Inc. Track support for supporting a flexible track

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US937793A (en) * 1908-04-28 1909-10-26 Philip J Haas Fence-post mold.

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US937793A (en) * 1908-04-28 1909-10-26 Philip J Haas Fence-post mold.

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3126671A (en) * 1964-03-31 Method of prefabricating the block
US2763464A (en) * 1952-07-26 1956-09-18 Leonhardt Fritz Apparatus for anchorage of concrete reinforcements
DE1186700B (de) * 1958-05-20 1965-02-04 Internat Pipe And Ceramics Cor Betonrohr mit vorgespannten Bewehrungsringen in der Naehe der Rohrenden
US3341176A (en) * 1964-01-22 1967-09-12 Baltimore Concrete Plank Corp Apparatus for imparting tension to a reinforcing cable of u-shaped configuration
US3399434A (en) * 1965-09-27 1968-09-03 William F. Kelly Anchors for stressed cables
US3774359A (en) * 1971-03-15 1973-11-27 B Kahn Reinforced concrete plate construction
US4313287A (en) * 1980-01-25 1982-02-02 Romig Jr Byron A Internally tensioned structural member and method of assembling same
US4398377A (en) * 1980-01-25 1983-08-16 Romig Jr Byron A Structural member with equalized internal tension
US4537388A (en) * 1982-05-14 1985-08-27 Mccabe Francis B Adjustable tensioning device
US4683632A (en) * 1985-09-09 1987-08-04 Caterpillar Inc. Track support for supporting a flexible track

Also Published As

Publication number Publication date
CH271051A (de) 1950-10-15
BE491207A (enrdf_load_stackoverflow)

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