EP-4735206-A1 - POWERED TOOL FOR TIGHTENING THREADED CONNECTIONS

Abstract

There is provided herein a powered tool for tightening threaded connections, comprising: a housing (1600) comprising a slotted opening (200); a slotted gear (120, 210) mechanism comprising a slotted gear (120, 210) and a plurality of rotating gripper cams; a transmission plate (130) rotationally coupled to the slotted gear (120, 210), wherein the transmission plate (130) is linked to the gripper cams via the slotted gear (120, 210) mechanism such that rotation of the transmission plate (130) causes rotation of the gripper cams; a biasing means arranged to urge the transmission plate (130) such that the gripper cams are rotated towards the circumference of the housing (1600); and a linkage, in mechanical communication with both the slotted gear (120, 210) and the transmission plate (130), comprising a biased ratchet (105), the linkage arranged such that: rotation of the slotted gear (120, 210) in a first direction causes the linkage to engage on the ratchet (105), thereby rotating the transmission plate (130) to compress the biasing means and rotate the gripper cams such that, in use, their grip on a bar (135) passing through the slotted housing (1600) is loosened; and rotation of the slotted gear (120, 210) in a second direction causes the transmission plate (130) to rotate and rotate the gripper cams such that, in use, their grip on a bar (135) passing through the slotted housing (1600) is tightened.

Inventors

• CALLEAR, Jason
• DIAZ DE RADA LORENTE, CARLOS

Assignees

• Laing O'Rourke Plc

Dates

Publication Date

20260506

Application Date

20240619

Claims (20)

1. 1 . A powered tool for tightening threaded connections, comprising: a housing comprising a slotted opening; a slotted gear mechanism comprising a slotted gear and a plurality of rotating gripper cams; a transmission plate rotationally coupled to the slotted gear, wherein the transmission plate is linked to the gripper cams via the slotted gear mechanism such that rotation of the transmission plate causes rotation of the gripper cams; a biasing means arranged to urge the transmission plate such that the gripper cams are rotated towards the circumference of the housing; and a linkage, in mechanical communication with both the slotted gear and the transmission plate, comprising a biased ratchet, the linkage arranged such that: rotation of the slotted gear in a first direction causes the linkage to engage on the ratchet, thereby rotating the transmission plate to compress the biasing means and rotate the gripper cams such that, in use, their grip on a bar passing through the slotted housing is loosened; and rotation of the slotted gear in a second direction causes the transmission plate to rotate and rotate the gripper cams such that, in use, their grip on a bar passing through the slotted housing is tightened.
2. 2. The tool of any preceding claim, wherein the biased ratchet is a sprung ratchet.
3. 3. The tool of claim 2, wherein the sprung ratchet comprises a soft spring in a first direction and a hard spring in a second direction,
4. 4. The tool of claim 3, wherein the hard spring has a spring rate set to allow deflection of the ratchet at predetermined stress levels within the slotted gear mechanism.
5. 5. The tool of any preceding claim, wherein the transmission plate comprises one or more slotted holes.
6. 6. The tool of claim 5, wherein the one or more slotted holes control the point at which rotation of the transmission plate causes one or more of the gripper cams to rotate.
7. 7. The tool of any preceding claim, wherein one or more of the gripper cams has any of: a bar contact profile, and/or serrated teeth.
8. 8. The tool of claim 7, wherein the serrated teeth are oriented to, in use, dig into a bar surface under rotation of the slotted gear in the second direction, and perform a sharpening action when running over a bar surface under rotation of the slotted gear in the first direction.
9. 9. The tool of any preceding claim, wherein the slotted gear is rotationally held in position by an open plain bearing located between the slotted gear and the housing.
10. 10. The tool of any preceding claim, wherein the slotted gear is driven by one or more idler gears.
11. 11 . The tool of claim 10, wherein the one or more idler gears are driven by a single drive gear.
12. 12. The tool of claim 10 or 11 , wherein the idler gear spacing is such that the slotted gear remains driven at all times.
13. 13. The tool of claim 11 , wherein the single gear is driven by a motor assembly.
14. 14. The tool of claim 13, wherein the motor assembly comprises a gearbox.
15. 15. The tool of claim 13 or 14, wherein the motor is separate from the tool and is connected either to a gearbox or directly to the single drive gear via a socket.
16. 16. The tool of any preceding claim, wherein the housing is operable to substantially encapsulate two or more bars in contact with one another.
17. 17. The tool of any preceding claim, further comprising one or more strain gauges.
18. 18. The tool of any preceding claim, wherein the ratchet is indexed to the transmission plate such that under rotation in a first direction, alignment of the slotted opening of the housing with a slotted opening of the slotted gear coincides with the slotted opening being substantially clear of any portion of the gripper cams.
19. 19. A method of tightening threaded connections using a powered tool as claimed in any preceding claim.
20. 20. A method of tightening threaded connections, comprising: using a powered tool having: a housing comprising a slotted opening; a slotted gear mechanism comprising a slotted gear and a plurality of rotating gripper cams; a transmission plate rotationally coupled to the slotted gear, wherein the transmission plate is linked to the gripper cams via the slotted gear mechanism such that rotation of the transmission plate causes rotation of the gripper cams; a biasing means arranged to urge the transmission plate such that the gripper cams are rotated towards the circumference of the housing; and a linkage, in mechanical communication with both the slotted gear and the transmission plate, comprising a biased ratchet: the method comprising: rotating the slotted gear in a first direction causing the linkage to engage on the ratchet, thereby rotating the transmission plate to compress the biasing means and rotate the gripper cams such that, in use, their grip on a bar passing through the slotted housing is loosened; and rotating the slotted gear in a second direction causing the transmission plate to rotate and rotate the gripper cams such that, in use, their grip on a bar passing through the slotted housing is tightened.

Description

POWERED TOOL FOR TIGHTENING THREADED CONNECTIONS Background [0001] Reinforcing bars, commonly known as "rebars," are steel bars used to reinforce concrete structures by adding tensile strength to the material. In reinforced concrete structures, rebars are joined together to form a network of interconnected bars that provide additional strength and durability to the structure. Two common methods of joining rebars are lapping and screwing. [0002] Lapping involves laying two rebars next to each other and locking them together by pouring concrete around them. This creates an overlapping region where the two rebars are connected, which increases the overall strength of the structure. Screwing involves connecting two rebars end-to-end using a screwed connector. Screwed connectors are devices that allow two rebars to be rotated relative to each other and then locked in place. These connectors are typically set to a pre-defined torque, which ensures that the joint is strong enough to withstand the loads it will experience over the life of the structure. Summary [0003] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. [0004] There is provided herein a compact and automated tool for tightening standard rebar connectors. Other types of bar may additionally or alternatively be used in conjunction with this tool. A slotted drive gear is placed over the connector barrel or rebar. Rotation in one direction causes finger cams, also referred to interchangeably as gripper cams or clamping fingers, to lock on, transferring rotation to the barrel or bar. [0005] The slope on the finger cam may be such that significant forces are generated perpendicular to the surface of the barrel or bar. If there is external resistance to the barrel or bar rotating, then the finger cams lock on harder, enabling higher torque to be transferred. The torque applied via the drive gear is monitored and recorded to confirm the correct connector setting torque is applied. [0006] Reverse rotation of the slotted drive gear causes the finger cams to loosen on the connector barrel or rebar. Reverse rotation continues until the slot in the slotted drive gear aligns with the slot in the housing. During the last stages of alignment the finger cams may retract fully into the slotted gear such that the tool can be removed ready for positioning on the next connector. [0007] The combination of finger cam angles and activation mechanism result in a side access “slot over” tool that can manage a relatively large diametric range of couplers and bars. This makes the tool more versatile in use, with fewer tools necessary to cover the range of coupler diameters encountered on a construction site. [0008] A first aspect provides a powered tool for tightening threaded connections, comprising: a housing comprising a slotted opening; a slotted gear mechanism comprising a slotted gear and a plurality of rotating gripper cams; a transmission plate rotationally coupled to the slotted gear, wherein the transmission plate is linked to the gripper cams via the slotted gear mechanism such that rotation of the transmission plate causes rotation of the gripper cams; a biasing means arranged to urge the transmission plate such that the gripper cams are rotated towards the circumference of the housing; and a linkage, in mechanical communication with both the slotted gear and the transmission plate, comprising a biased ratchet, the linkage arranged such that: rotation of the slotted gear in a first direction causes the linkage to engage on the ratchet, thereby rotating the transmission plate to compress the biasing means and rotate the gripper cams such that, in use, their grip on a bar passing through the slotted housing is loosened; and rotation of the slotted gear in a second direction causes the transmission plate to rotate and rotate the gripper cams such that, in use, their grip on a bar passing through the slotted housing is tightened. [0009] A further aspect provides a method of tightening threaded connections, comprising: using a powered tool having: a housing comprising a slotted opening; a slotted gear mechanism comprising a slotted gear and a plurality of rotating gripper cams; a transmission plate rotationally coupled to the slotted gear, wherein the transmission plate is linked to the gripper cams via the slotted gear mechanism such that rotation of the transmission plate causes rotation of the gripper cams; a biasing means arranged to urge the transmission plate such that the gripper cams are rotated towards the circumference of the housing; and a linkage, in mechanical communication with both the slotted gear and the transmission plate, comprising a biased ratchet: the meth