NZ788937B2 - A Coupling Device, Associated Parts and a Method of Use Thereof - Google Patents

Abstract

Described herein is a coupler and method of coupling a reinforcing bar. The coupler may be configured to couple together reinforcing bar ends, the coupler comprising: a sleeve with an inner surface that encloses, coaxially, an end of a first reinforcing bar to be coupled and an end of a second reinforcing bar to be coupled; an array of pins configured to mechanically interlock the sleeve and first and second reinforcing bar ends, the pins fitted, with interference, tangentially and generally orthogonally to the longitudinal length of the first and second reinforcing bar ends, between the sleeve inner surface and first and second reinforcing bar ends so that the pins in the array, on fitting, cause local plastic deformation about part of an outer surface of the first or second reinforcing bar ends. The method of coupling may comprise coupling a first and second reinforcing bar by inserting an end of a first reinforcing bar to be coupled and an end of a second reinforcing bar to be coupled, into the coupler sleeve, the first and second reinforcing bar ends being coaxially aligned; and fitting an array of pins, with interference, tangentially and generally orthogonally to the longitudinal length of the first and second reinforcing bars, between the sleeve interior face and reinforcing bar end, so that the pins in the array cause local plastic deformation about part of an outer surface of the first or second reinforcing bar, the pin array mechanically interlocking the sleeve and first and second reinforcing bar ends together. The coupler and method provide a versatile and strong coupling.

Claims (35)

WHAT IS CLAIMED IS:

1. A reinforcing bar coupling system comprising first and second reinforcing bars and a coupler, the coupler being configured to couple together an end of the first reinforcing bar and an end of the second reinforcing bar, the coupler comprising: 5 a sleeve with an inner surface that encloses, coaxially, the first reinforcing bar end to be coupled and the second reinforcing bar end to be coupled; an array of pins configured to mechanically interlock the sleeve and first and second reinforcing bar ends, the pins fitted, with interference, tangentially and generally orthogonally to the longitudinal length of the first and second reinforcing bar ends, between the sleeve inner surface and first and second 10 reinforcing bar ends so that the pins in the array, on fitting, cause local plastic deformation about part of an outer surface of the first and/or second reinforcing bar ends; wherein the coupler is configured so that, when a tractive force is applied to the interlocked sleeve and reinforcing bars, material of at least one of the reinforcing bars piles up or shears before at least one pin of the array of pins.

2. The coupling system as claimed in claim 1 wherein the array once fitted comprises a first row of pins inserted on one side of the first and/or second reinforcing bar ends, and a second row of pins inserted on another side of the first and/or second reinforcing bar ends. 20

3. The coupling system as claimed in claim 2, wherein pins in each row of the array once fitted are located perpendicular to a longitudinal axis of the first and second reinforcing bar ends, and the pins in the first row are located opposite the pins in the second row.

4. The coupling system as claimed in claim 2, wherein pins in each row of the array once fitted are 25 located perpendicular to a longitudinal axis of the first and second reinforcing bar ends, and the pins in the first row are offset from the pins in the second row.

5. The coupling system as claimed in any one of claims 1 to 4, wherein the array once fitted comprises three or more pins in each row of the array.

6. The coupling system as claimed in any one of claims 1 to 5, wherein, once the pin array is fitted, the first reinforcing bar is mechanically interlocked by two rows of three or more pins and the second reinforcing bar end is mechanically interlocked by two rows of three or more pins.

7. The coupling system as claimed in any one of claims 1 to 6, wherein, before and after pin insertion, the pins remain straight. 5

8. The coupling system as claimed in any one of claims 1 to 7, wherein, each pin in the array, prior to fitting, has a generally straight elongated and slender form along its body and two opposing ends, one end being a leading end and a second end being a following end, the leading end entering first between the sleeve and reinforcing bar end during fitting. 10

9. The coupling system as claimed in claim 8, wherein the leading ends of the pins in the array remain within the sleeve once the pins are fitted.

10. The coupling system as claimed in any one of claims 1 to 9, wherein each pin in the array once fitted, is embedded in the sleeve and/or reinforcing bar to a pin diameter (PED ratio) of at least 15%.

11. The coupling system as claimed in any one of claims 1 to 10, wherein the local plastic deformation is generated on fitting of the pins between the sleeve and reinforcing bar via use of continuous pressure to forcibly insert each pin in the array between the sleeve inner surface and an adjacent outer surface of the first or second reinforcing bar end.

12. The coupling system as claimed in claim 11, wherein the continuous pressure is a press configured to press fit one or more pins between the inner surface of the sleeve and an adjacent outer surface of the first or second reinforcing bar ends. 25

13. The coupling system as claimed in in any one of claims 1 to 12, wherein each pin, when fitted, passes through at least one orifice on the exterior of the sleeve to at least one groove recessed into the sleeve inner surface, wherein the at least one orifice and/or at least one groove is/are formed in part or in full before coupling and wherein the orifice is undersized relative to the pin size to ensure an interference fit of the pin into the orifice.

14. The coupling system as claimed in any one of claims 1 to13, wherein, the pins in the array, on fitting, also cause local, and predominantly plastic deformation, about part of the inner surface of the sleeve.

15. The coupling system as claimed in any one of claims 1 to 14, wherein adhesive is located between the inner surface of the sleeve and the outer surface of at least one of the reinforcing bars, the adhesive fusing and/or bonding one or more pins of the array and either, or both, the inner surface of the sleeve, or 5 the outer surface of the at least one of the reinforcing bars.

16. The coupling system as claimed in claim 15, wherein the adhesive is present in the sleeve prior to fitment of the at least one of the reinforcing bars into the sleeve. 10

17. The coupling system as claimed in claim 15, wherein the adhesive is applied between the sleeve and the at least one of the reinforcing bars after fitment of the at least one of the reinforcing bars into the sleeve.

18. The coupling system as claimed in claim 15, wherein the adhesive is selected from: chemical 15 adhesive, flux, metal plating, alloying elements, and chemical bonding.

19. The coupling system as claimed in claim 15, wherein the adhesive is a two component epoxy product in a vial that is preinstalled into the sleeve and configured so that, when the at least one of the reinforcing bars is installed in the sleeve, the vial is fractured releasing the adhesive.

20. The coupling system as claimed in any one of claims 1 to 14, wherein one or more pins of the array and the sleeve inner surface and/or the outer surface of at least one of the reinforcing bars are configured to provide a camming action of the one or more pins relative to the sleeve inner surface and/or at least one reinforcing bar outer surface, as axial displacement occurs between the at least one reinforcing bar and 25 sleeve during axial loading of the first and second reinforcing bars and sleeve.

21. The coupling system as claimed in claim 20 wherein the camming action increases interference between the one or more pins and the at least one reinforcing bar. 30

22. The coupling system as claimed in claim 20 wherein the camming action decreases interference between the one or more pins and the at least one reinforcing bar.

23. The coupling system as claimed in claim 20 wherein the camming action results in rotation of the one or more pins on application of an axial force, embedding an edge of the one or more pins further into the at least one reinforcing bar. 5

24. The coupling system as claimed in claim 20 wherein at least one pin in the array, prior to fitting, has a generally straight elongated and slender form along its body and two opposing ends and, at least one further pin in the array, prior to fitting, has a shape configured to provide a camming action.

25. A method of coupling a first and second reinforcing bars, the method comprising the steps of: 10 providing a sleeve having an inner surface; inserting an end of a first reinforcing bar to be coupled and an end of a second reinforcing bar to be coupled, into the sleeve, the first and second reinforcing bar ends being coaxially aligned; and fitting an array of pins, with interference, tangentially and generally orthogonally to the longitudinal length of the first and second reinforcing bars, between the sleeve interior face and reinforcing 15 bar end, so that the pins in the array cause local plastic deformation about part of an outer surface of the first or second reinforcing bar, the pin array mechanically interlocking the sleeve and first and second reinforcing bar ends together; wherein, when a tractive force is applied to the interlocked first and second reinforcing bars and sleeve, material of at least one of the reinforcing bars piles up or shears before at least one pin of the array 20 of pins.

26. The method as claimed in claim 25, wherein the at least one pin is fitted with interference by applying a force to the pin by continuous pressure. 25

27. The method as claimed in claim 25, wherein the continuous pressure is a press configured to press one or more pins in the array between part of the inner surface of the sleeve and into an adjacent outer surface of the first or second reinforcing bar.

28. The method as claimed in claim 26 or claim 27, wherein, multiple pins in the array are pressed during 30 fitting.

29. The method as claimed in claim 25, wherein the pins in the array on fitting, also cause local, and predominantly plastic deformation, about part of the inner surface of the sleeve.

30. The method as claimed in claim 25, wherein prior to fitment of at least one of the first and second reinforcing bars into the sleeve, adhesive is located between the inner surface of the sleeve and the outer 5 surface of the at least one reinforcing bar, the adhesive configured to fuse and/or bond the at least one pin and either, or both, the inner surface of the sleeve, or the outer surface of the at least one reinforcing bar.

31. The method as claimed in claim 25, wherein after to fitment of the at least one reinforcing bar into the sleeve, adhesive is located between the inner surface of the sleeve and the outer surface of the at least 10 one reinforcing bar, the adhesive configured to fuse and/or bond the at least one pin and either, or both, the inner surface of the sleeve, or the outer surface of the at least one reinforcing bar.

32. The method as claimed in claim 25, wherein the at least one pin and sleeve inner surface and/or at least one reinforcing bar outer surface are configured to provide a camming action of the at least one pin 15 relative to the sleeve inner surface and/or at least one reinforcing bar outer surface, as axial displacement occurs between the at least one reinforcing bar and sleeve during axial loading of the at least one reinforcing bar and sleeve.

33. The method as claimed in claim 32, wherein the camming action results in rotation of the at least 20 one pin on application of an axial force, embedding an edge of the at least one pin further into the at least one reinforcing bar.

34. The coupling system as claimed in claim 1, the reinforcing bar coupling system being substantially as hereinbefore described with reference to the accompanying drawings.

35. The method as claimed in claim 25, the method being substantially as hereinbefore described with reference to the accompanying drawings.