CONNECTING ELONGATE MEMBERS

Abstract: The invention relates to a set of parts for effecting connection of elongate members, characterised by a first sleeve part (4) having an internal bore (5), by one end of the bore having interengagement means (6) by a second sleeve part (7) having a blind bore (8) and an extension (9) which has external interengagement means (10), and by the arrangement being such that in use with the sleeve parts (4, 7) connected by their respective interengagement means (6, 10), elongate members (2, 3) engaged in the respective bores (5, 8) are connected. The sleeve parts (4, 7) are each substantially cylindrical and have the same or substantially the same outside diameter so that contacting faces (13, 14) provide support in compression and resistance to bending.

Description: CONNECTING ELONGATE MEMBERS The invention relates to connecting elongate members, particularly deformed (ribbed) reinforcing bars used in concrete construction, e.g. for building construction. Such deformed reinforcing bars are usually made of steel and are often incorporated in concrete when it is poured during construction of a building, the reinforcing bars providing strength to the set concrete, which might otherwise crack or spall under load. The area of the concrete is often extensive, and the bars, being of finite length often have to be secured together or spliced in situ to provide continuous lengths of reinforcing bars during concrete construction. The deformed reinforcing bars are used together to provide a reinforcement which is tensioned to generate a compressive stress in the concrete. In the past a system of sleeves and bolts has been used, but this system suffers from the disadvantages of expense, and the need to use a separate bolt, which can readily be mislaid, so halting or at best slowing down, the construction process, which can render the whole construction uneconomic. It is accordingly an object of the invention to seek to mitigate these disadvantages. According to a first aspect of the invention, there is provided a set of parts for effecting connection of elongate members, comprising a first sleeve part having an internal bore one end of which has interengagement means and a second sleeve part having a blind bore and an extension which has external interengagement means, the arrangement being such that in use with the sleeves connected by their respective interengagement means, elongate members engaged in the respective bores are connected. The sleeve parts may each be substantially cylindrical. This provides for ease of use and construction. The respective interengagement means may comprise screw threads. This is a relatively simple construction which also provides a firm connection. The extension of the second sleeve part may be at an end of the sleeve opposite the blind bore. This provides for provision of continuing or "line-line" connection of two elongate members. The respective sleeve parts may be deformable. This provides for a firm fixing to an elongate member. The respective bores may each have limit means, which may comprise a shoulder in each bore. This can define the position of the elongate member. According to a second aspect of the invention, there is provided a system, comprising a set of parts as hereinbefore defined, and at least two elongate members which are to be connected together. The elongate members of the system may comprise reinforcing bars for use in building construction. This provides for efficient connection of reinforcing bars when connected together in line on use of the system. There may be means for pressing or squeezing a respective sleeve and elongate member together. This provides for a firm connection, particularly when the pressing means may comprise a hydraulic press. According to a third aspect of the invention there is provided a method of connecting two elongate members, comprising providing a first sleeve part having an internal bore one end of which has interengagement means, providing a second sleeve part having a blind bore and an extension which has external interengagement means, mounting a first elongate member in the first sleeve part, mounting a second elongate member in the second sleeve part, securing a sleeve part to a respective elongate member, and then securing the sleeve parts together by interengagement of the respective interengagement means. The final securing step may be effected manually. This provides for simplicity and ease of use on site, particularly when tongs or pliers are used. The step of securing a sleeve part to an elongate member may be by pressure. This is a simple yet effective method, particularly when the said securing step may be effected using hydraulic pressure. The said securing step may be by deforming the sleeve onto the elongate member. This provides a uniform connection over the whole surface area of the elongate member. According to a fourth aspect of the invention there is provided a reinforcement for use in building construction, comprising reinforcing bars secured together using a set of parts as hereinbefore defined, a system as hereinbefore defined or a method as hereinbefore defined. According to a fifth aspect of the invention there is provided concrete whenever reinforced by a reinforcement as hereinbefore defined in the immediately preceding paragraph. A set of parts, system and method for effecting connection to elongate members in the form of reinforcing bars for use in building construction are hereinafter described, by way of example, with reference to the accompanying drawing. Fig. 1 is a side elevational view of a first sleeve part, connected to a first reinforcing bar; Fig. 2 is a side elevational view of a second sleeve part, connected to a second reinforcing bar;; Figs. 3A, 3A,', 3B, and 3B' show enlarged longitudinal sectional views of the first sleeve part- Figs. 4A, 4A', 4B and 4B' show enlarged longitudinal sectional views of the second sleeve part; and Figs. 5A and 5B show to an enlarged scale a set of parts according to the invention respectively disconnected and connected. Referring to the drawings, there is shown a set of parts 1 for effecting connection of elongate members 2, 3 in the embodiment steel reinforcing bars for use in reinforcing concrete in building construction, the set of parts comprising a first sleeve part 4 having an internal bore 5 one end of which has interengagement means in the form of a screw thread 6 and a second sleeve part 7 having a blind bore 8 and an extension 9, directed in an opposite direction to the blind bore 8, which extension 9 has external interengagement means in the form of a screw thread 10. Both sleeve parts 4, 7 are made of metal which in the embodiment is similar in hardness to or softer than that of the reinforcing bars 2, 3. The end of the threaded part of the bore 5 of the first sleeve part 4 is defined by an internal limit or stop means 1 1 in the form of a shoulder which projects into bore 5 and effectively reduces the diameter of the bore 5 to provide a positive stop. The blind end of the blind bore 8 of the second sleeve part 7 defines a limit means 1 2. The two sleeve parts 4, 7 with the reinforcing bars 2, 3 form a system which with a means such as a hydraulic press (not shown) is used for connecting the reinforcing bars 2,3 together in line to form a continuous reinforcement for concrete in building construction. In use, the reinforcing bar 2 is inserted in the bore 5 of the first sleeve part 4, up to the limit means 1 1 . The reinforcing bar 3 is inserted into the blind bore 8 of the second sleeve part 7 up to the limit means 1 2. The respective positions of the reinforcing bars 2,3 are then known because the respective limit means 1 1 , 1 2 provide a positive indication that the reinforcing bars 2, 3 are fully inserted in their respective sleeve parts 4, 7. The sleeve parts 4, 7 are then inserted in pressing means such as a hydraulic press to deform the metal of the respective sleeve part 4 or 7 which is upset or swaged onto the respective reinforcing bar 2 or 3, the respective limit means 1 1 , 1 2 also being deformed to provide a lock or positive connection onto the respective reinforcing bar 4 or 7. This can be effected off site. On site, in order to provide a larger bar, the threaded extension 9 and threaded part 6 of the bore of the first sleeve part 4 are screwed together, being complementary; this can be effected manually, using if necessary tongs or pliers as no particular torque is required. In every embodiment the sleeve parts 4 and 7 have the same external diameter, and in use facing and engaging surfaces 1 3, 14 thereof are flat and substantially at 90 ° to the length and provide a full, annular bearing over the same contacting surface area. The sleeve part 4, 7 being of the same diameter has the advantage that the sleeves as shown have a cross-sectional area which is much greater than that of the reinforcing bars, or rebars 2, 3. When connected with the surfaces 13, 14 in contact, support is provided for both the connection and the rebars so a greatly enhanced compression strength and bending strength resistance is achieved, which mitigates the risk of failure in situ. A reinforcement is thus provided as a double threaded press sleeve joint for deformed reinforcing steel bars in which in the reinforcement the sleeve parts 4, 7 do not interfere with the characteristics of the reinforcing bars 2, 3 and the permissable working load of the connected system is not reduced as compared with that of an unconnected reinforcing bar. The system allows testing of the connection for desired and controlled quality and is easy to use as no special pre-preparation which could weaken the reinforcing bar is necessary. The part of the method which is most time-consuming, that of mounting the sleeve parts on the reinforcing bars, can be carried out off site, thereby not interfering with the construction process, in the final reinforcement, the two reinforcing bars being essentially screw threaded together on site without the need for additional bolts, therefore reducing time, the possibility of loss of a bolt, mistakes of a user, and cost.

Claims: CLAIMS 1 . A set of parts for effecting connection of elongate members, characterised by a first sleeve part (4) having an internal bore (5), by one end of the bore having interengagement means (6) by a second sleeve part (7) having a blind bore (8) and an extension (9) which has external interengagement means ( 10), and by the arrangement being such that in use with the sleeve parts (4), (7) connected by their respective interengagement means (6, 10), elongate members (2, 3) engaged in the respective bores (5, 8) are connected. 2. A set of parts according to Claim 1 , characterised by the sleeve parts (4), (7) each being substantially cylindrical. 3. A set of parts according to Claim 1 or Claim 2, characterised by the respective interengagement means (6, 10) comprising screw threads. 4. A set of parts according to Claim 2 or Claim 3, characterised by the extension (9) of the second sleeve part (7) being at an end of the sleeve part opposite the blind bore (8). 5. A set of parts according to any preceding claim, characterised by the respective sleeve parts (4, 7) being deformable. 6. A set of parts according to any preceding claim, characterised by the respective bores (5, 8) each having limit means. 7. A set of parts according to Claim 6, characterised by the limit means comprising a shoulder ( 1 1 , 1 2) in a respective bore (5) or (8) . 8. A set of parts according to any of claims 2 to 7, characterised by the sleeve parts (4, 7) having substantially the same external diameters. 9. A system, comprising a set of parts according to any preceding claim, characterised by at least two elongate members (2, 3) which are to be connected together. 10. A system according to Claim 9, characterised by the elongate members (2, 3) comprising reinforcing bars for use in building construction. 1 1 . A system according to Claim 10, characterised by the reinforcing bars (2, 3) being connected together in line in use of the system. 1 2. A system according to Claim 1 1 , characterised by means for pressing a respective sleeve and elongate member together. 13. A system according to Claim 1 2, characterised by the pressing means comprising a hydraulic press. 14. A method of connecting two elongate members, characterised by providing a first sleeve part (4) having an internal bore (5) one end of which has interengagement means (6), providing a second sleeve (7) part having a blind bore (8) and an extension (9) which has external interengagement means ( 10), mounting a first elongate member (2) in the first sleeve part (4), by mounting a second elongate member (3) in the second sleeve part (7), by securing a sleeve part (4, 7) to a respective elongate member (2, 3), and by securing the sleeve parts (4, 7) together so that facing surfaces of a substantially identical diameter are engaged by interengagement of the respective interengagement means (6, 10). 15. A method according to Claim 14, characterised by the final securing step being effected manually. 16. A method according to Claim 15, characterised by the step of securing a sleeve part (4, 7) to an elongate member (2, 3) being by pressure. 17. A method according to Claim 16, characterised by the said securing step being effected using hydraulic pressure. 18. A method according to Claim 17, characterised by the said securing step deforming the sleeve part (4, 7) on to the elongate member (2, 3). 19. A reinforcement for use in building construction, characterised by reinforcing bars (2, 3) secured together using a set of parts according to any of Claims 1 to 8, a system according to any of Claims 9 to 12, or a method according to any of Claims 15 to 18. 20. Concrete, characterised by being reinforced by a reinforcement according to Claim 19.

Inventors: AMORNTATKUL NOPPADOL, BUEHLER RAINER, AMORNTATKUL, NOPPADOL, BUEHLER, RAINER
Applicants: AMORNTATKUL NOPPADOL, BUEHLER RAINER, JOHNSON TERENCE LESLIE, AMORNTATKUL, NOPPADOL, BUEHLER, RAINER, JOHNSON, TERENCE, LESLIE
Application year: 1999
Main classification: E04C5
IPC codes: E04C5