Tool for threaded rebar connections
An automated rebar connection device with a slotted drive gear and finger cams addresses misalignment and torque challenges, enabling efficient and consistent connection of reinforcing bars across different diameters, thereby reducing labor and project delays.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2024-06-19
- Publication Date
- 2026-07-08
AI Technical Summary
Existing methods for connecting reinforcing bars in concrete structures, such as lapping and screwing, face challenges with misalignment, increased torque requirements due to dirty threads, and labor-intensive operations, leading to delays in construction projects.
An automated device with a slotted drive gear and finger cams that applies torque to threaded connectors, featuring a mechanism to lock and loosen securely, accommodating various bar diameters, and includes a digital memory for record-keeping.
Facilitates efficient and consistent tightening of rebar connections across varying diameters, reducing labor requirements and project delays by ensuring proper torque application and allowing for reuse.
Smart Images
Figure 2026522715000001_ABST
Abstract
Description
Background Art
[0001] Reinforcing bars, generally called "rebars", are steel bars and are used to reinforce concrete structures by adding tensile strength to the material. In a reinforced concrete structure, the rebars are joined together to form a network structure of interconnected bars, which provide additional strength and durability to the structure. Two common methods of joining rebars are lapping and screwing.
[0002] In lapping, two rebars are arranged side by side and locked together by pouring concrete around them. This forms an overlapping area where the two rebars are connected, increasing the overall strength of the structure. In screwing, threaded connectors are used to connect the ends of two rebars. Threaded connectors are devices that allow two bars to be rotated relative to each other and then locked in place. These connectors are usually set to a pre-defined torque, so that the joint has sufficient strength to withstand the loads experienced over the life of the structure.
Summary of the Invention
Means for Solving the Problems
[0003] The summary of this invention is provided to briefly introduce selected concepts, which will be further described in the following detailed description of the invention. The summary of this invention is not intended to identify the 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] This specification provides a small, automated device for tightening standard rebar connectors. Other types of rebar can be used with this device as an addition or alternative. A slotted drive gear is positioned above the connector barrel or rebar. When rotated in one direction, a finger cam, also called a gripper cam or clamping finger, locks and transmits the rotation to the barrel or rebar.
[0005] The gradient on the finger cam may be such that it generates a significant force perpendicular to the surface of the barrel or bar stock. When there is external resistance to the rotation of the barrel or bar stock, the finger cam can lock more tightly, allowing for the transmission of higher torque. The torque applied via the drive gear is monitored and recorded to ensure that the correct connector setting torque is being applied.
[0006] Reverse rotation of the slotted drive gear loosens the finger cam against the connector barrel or rebar. Reverse rotation continues until the slots of the slotted drive gear align with the slots in the housing. During the final stage of alignment, the finger cam can be fully retracted into the slotted gear, thereby preparing the device for removal and positioning onto the next connector.
[0007] The combination of the finger cam angle and the operating mechanism results in a side-access "slot-over" tool that can handle fittings and rods with a relatively large diameter range. This broadens the tool's applications and reduces the number of tools needed to cover the range of fitting diameters encountered on construction sites.
[0008] The first embodiment provides an electric device for tightening threaded connections, the device comprising: a housing having a slotted opening; a slotted gear mechanism comprising a slotted gear and a plurality of rotating gripper cams; a transmission plate rotatably coupled to the slotted gear, the transmission plate being linked to the gripper cams via the slotted gear mechanism such that the gripper cams rotate when the transmission plate rotates; a biasing means constructed to bias the transmission plate so that the gripper cams rotate toward the circumference of the housing; and both the slotted gear and the transmission plate and mechanically The device is configured to be connected to a linkage and equipped with a biased ratchet, wherein when the slotted gear rotates in a first direction, the linkage engages with the ratchet, thereby rotating a transmission plate to compress the biasing means and rotate the gripper cam, thereby loosening the gripper cam's grip on the rod passing through the slotted housing during use, and when the slotted gear rotates in a second direction, the transmission plate rotates to rotate the gripper cam, thereby tightening the gripper cam's grip on the rod passing through the slotted housing during use.
[0009] A further embodiment is a method for tightening a threaded connection, using an electric tool, the electric tool comprising: a housing having a slotted opening; a slotted gear mechanism comprising a slotted gear and a plurality of rotating gripper cams; a transmission plate rotatably coupled to the slotted gear, the transmission plate being linked to the gripper cams via the slotted gear mechanism such that the gripper cams rotate when the transmission plate rotates; a biasing means configured to bias the transmission plate so that the gripper cams rotate toward the circumference of the housing; and the slotted gear and the transmission plate A method comprising a linkage having a biased ratchet and being mechanically connected to both, the method including rotating a slotted gear in a first direction to engage the linkage on the ratchet, thereby rotating a transmission plate to compress the biasing means and rotate a gripper cam, thereby loosening the gripper cam's grip on a rod passing through a slotted housing in use, and rotating the slotted gear in a second direction to rotate the transmission plate and rotate a gripper cam, thereby tightening the gripper cam's grip on a rod passing through a slotted housing in use.
[0010] Preferred features can be appropriately combined as will be apparent to those skilled in the art, and can be combined with any of the embodiments of the present invention.
[0011] Embodiments of the present invention will be described as an example with reference to the following drawings. [Brief explanation of the drawing]
[0012] [Figure 1] This is a cross-sectional view of a device for connecting threaded reinforcing bars. [Figure 2] This is a diagram showing the initial state of the equipment. [Figure 3] This diagram shows the device used to initiate clockwise rotation. [Figure 4] This diagram shows the device when the clamping fingers first make contact with the rod. [Figure 5]It is a diagram showing the device when the bar starts to rotate. [Figure 6] It is a diagram showing the device when the bar continues to rotate. [Figure 7] It shows the device when the bar continues to rotate further. [Figure 8] It is a diagram showing how the rotation increases to a predetermined torque. [Figure 9] It is a diagram showing the situation where the device starts to rotate counterclockwise. [Figure 10] It is a diagram showing the situation where the device continues to rotate counterclockwise. [Figure 11] It is a diagram showing the situation where the device continues to rotate counterclockwise further. [Figure 12] It is a diagram showing the state where the clamp fingers of the device are completely retracted. [Figure 13] It is a diagram showing the state where the slotted gear of the device is at rest. [Figure 14] It is a diagram showing further details regarding the clamp fingers. [Figure 15] It is a diagram showing the situation where the device is gripping bars of different sizes respectively. [Figure 16] It is a diagram showing the appearance of an exemplary housing for the device. [Figure 17] It is a diagram showing the appearance of the lower side of the exemplary housing. [Figure 18] It is a top view of the device with the upper housing removed. [Figure 19] It is three diagrams showing the situation of the device where the slotted gear is receiving different amounts of rotation. [Figure 20] It is a diagram similar to FIG. 19 but showing the situation where the top of the slotted gear is removed.
Best Mode for Carrying Out the Invention
[0013] Common reference numbers are used throughout the drawings to indicate similar features.
[0014] The embodiments of the present invention will be described below only as an example. These examples represent the best ways to implement the present invention known to the applicant at present, but are not the only ways to achieve the present invention. In the description, the functions of the examples and the sequence of steps for constructing and operating the examples are described. However, the same or equivalent functions and sequences can be achieved by different examples.
[0015] When the reinforcing bars being joined are properly aligned axially and the threads are clean, the screwing process or the tightening process can be carried out relatively easily. In the actual construction environment, it is rare for the bars to be aligned, and the threads may be dirty. In this case, the torque required to form a sufficiently strong connection increases. When most of the threads can no longer be screwed in by hand, the time and labor required to carry out the construction increase significantly when construction workers need to use wrenches.
[0016] Generally, as the sizes of the bars and connectors increase, the required torque also increases. The labor itself becomes significant, and the tightening operation is further decelerated. Since the assembly of the connectors is usually located on the critical path of the construction plan, a delay in the progress regarding the tightening of the connectors may cause the entire project to be delayed. Furthermore, in a large-scale site, the available labor may be limited, that is, the labor used to screw in the connectors may interfere with the progress in other places.
[0017] Therefore, in this specification, an instrument that enables an electric motor to supply power to the rotation of connector components will be described. Since the instrument can be reusable, the means for transmitting torque to the connector cannot completely surround the reinforcing bar or the connector components. The reason is that in this case, the instrument may be permanently fixed to the bar. In fact, the instrument can be provided laterally to the reinforcing bar or the connector, and thus can be removable from the same side after the connector is configured with the correct torque.
[0018] Optionally, a two-part open-type sliding bearing is used, with one part mounted on a slotted gear and the other part positioned within the fixture housing. In this way, the slotted gear can rotate without being locked onto a rebar or joint. The bearing may be formed from copper, brass, plastic, or any other material capable of withstanding the required stress and strain. Self-lubricating materials may be used to form at least a portion of the bearing.
[0019] The locking mechanism may comprise multiple, for example, five, finger cams actuated by the rotation of a gear. The finger cams, positioned to pivot above the gear slot, may be configured to extend first. As the gear continues to rotate in the same direction, all finger cams extend simultaneously, capable of gripping the rebar or connector. Subsequent rotations cause the finger cams to grip the rebar or connector. The shape of the finger cams is such that the clamping force increases with increasing torque. Optionally, the finger cams may have a substantially "teardrop" shape.
[0020] Unlocking is achieved by reverse rotation compared to the locking rotation. This relieves the pressure on the finger cam, allowing it to slide over the rebar surface. As the gear slot approaches the slot in the housing, a lever on the housing engages with the operating lever on the slotted gear, pulling out the clamping fingers. The gear stops aligned with the housing slot, allowing the device to be removed from the rebar.
[0021] The fixture can be configured to accommodate reinforcing bars and connectors of various diameters. This allows a single fixture to be used in a variety of situations.
[0022] Optionally, the equipment may be equipped with digital memory, a processor, and other electronic devices configured to store all memories and / or databases of the rebar and / or connectors being fastened. Such records provide a useful checklist for construction workers and can help avoid unnecessary reinspections.
[0023] The weight of the equipment may be within the handling limits of human users, such as construction workers, but it may nevertheless be close to the upper limit of such limits. For this reason, the equipment may be provided without an integrated motor drive unit, although in other embodiments a motor drive unit may be integrated. A specific gearbox may be selected to reduce weight.
[0024] The apparatus can be used according to the following steps.
[0025] In the first step, the slot of the device is positioned above the rotating rod or connector component. The weight of the device may be supported on a hoist or counterweight system.
[0026] In the second step, the device is wedge-locked to prevent it from rotating when it is typically tightened against an adjacent rebar.
[0027] In the third step, the battery-powered hand drill is connected to the drive gearbox and operated in the forward direction. This releases the clamping fingers that are gripping the rod or connector. The subsequent rotation then rotates the rod or connector component.
[0028] In the fourth step, optionally, forward rotation continues until the required torque, set for the battery-powered hand drill, is reached.
[0029] Next, in the fifth step, the reverse rotation is activated. The gears and housing slots align, and the reverse rotation continues until the clamping fingers are pulled out.
[0030] In the sixth step, remove the device from the rod or connector.
[0031] Figure 1 shows some components of an exemplary clamp finger operating mechanism, also called a coupling module 100. A rotary transmission plate 130 moves relative to a slotted gear (not shown). A clamp finger 120 (partially shown) is mounted on a shaft having a bearing surface through the body of the slotted gear. A finger lever 125 is attached to one end of the shaft, and the clamp finger 120 is attached to the other end. As the transmission plate 130 rotates, the finger lever 125 rotates, and therefore the clamp finger 120 rotates. A system of closing springs 115 acts on the rotary transmission plate 130, causing the transmission plate 130 to rotate the clamp finger 120, thereby the closing springs 115 close the clamp finger 120 on the rod 135. It should be noted that other biasing means other than springs may be used in any application herein. The process of "closing" the clamp finger 120 occurs when the clamp finger 120 rotates so that it moves at least partially away from the circumference of the slotted gear 210, thereby gripping the rod 135 positioned within the slotted gear 210 during use. The process of "opening" the clamp finger 120 occurs when the clamp finger 120 rotates in the opposite direction so that it moves at least partially toward the circumference of the slotted gear 210, thereby releasing the grip on the rod 135 positioned within the slotted gear 210 during use.
[0032] Figure 1 also shows an exemplary release lever system 105, also called a ratchet 105. The small release lever 105 can pivot in both directions (as further shown in Figure 7). In the first direction, there is a weak spring 105', which allows the release lever 105 to easily pivot to avoid the actuating lever 110. In the second direction, there is a strong spring 105'', which causes the rotational transmission plate 130 to rotate relative to the slotted gear when the actuating lever 110 engages with the release lever 105. However, if the gear rotates beyond a predetermined amount, the rotational transmission plate 130 reaches its travel end and locks relative to the slotted gear. Further rotation of the slotted gear may cause mechanical damage to the release lever 105 or the actuating lever 110. The strong spring 105'' rotates and compresses before such damage occurs. The release lever system 105 may be mounted on a housing (not shown).
[0033] Figures 2 to 8 show the sequence for tightening the joint.
[0034] Figure 2 shows the starting state. The gear slot 200 is aligned with the slot in the housing (not shown). The actuating lever 110 is engaged on the release lever 105. The rotational transmission plate 130 rotates relative to the slotted gear 210. This compresses the spring 115. In this state, the slotted gear 210 can be positioned above the bar 135. The finger lever 125 is rotated by the rotational transmission plate 130, thereby completely retracting the clamping finger 120. The release lever 105 is aligned with the transmission plate 130, thereby continuing to rotate, and optionally continuing to rotate counterclockwise, so that the slotted opening in the housing and the slotted opening 200 in the slotted gear 210 are aligned, and at the same time, the slotted opening 200 is substantially separated from any part of the finger lever 125. This allows the bar or other equipment to be clamped to enter and exit.
[0035] Figure 3 shows the configuration when gear 210 begins to rotate clockwise. It should be noted that the device may alternatively be configured such that the clamping finger 120 closes above the bar 135 when gear 210 rotates counterclockwise, and the clamping finger 120 is released above the bar 135 when gear 210 rotates clockwise. The first clamping finger 120', closed above the slot, immediately begins to rotate. The clamping finger 120 remains in its starting position (or moves from its starting position due to slight friction in the system, but no force can be applied) because the pin 305 linking the finger lever 125 to the transmission plate 130 extends into the slot 310 for the other clamping finger 120. As gear 210 continues to rotate, the transmission plate 130 rotates relative to the actuation lever 110, which is still engaged with the release lever 105. The rotation continues until the pins 305 linking the finger levers 125 have rotated enough to reach the ends of their respective slots 310. At this point, the transmission plate 130 rotates all the clamping fingers 120 simultaneously.
[0036] Figure 4 shows the rotation of the transmission plate 130 continuing until the clamping fingers 120 contact the bar 135. At this point, the configuration is locked. The transmission plate 130 is then unable to rotate relative to the gear 210. The closing spring 115 continues to apply an initial clamping force to the transmission plate 130. Next, the operating lever 110 is released from contact with the release lever 105. The bar 135 is gripped due to the shape of the clamping fingers 120. The higher the torque required to rotate the bar 135, the more clamping fingers 120 are needed to grip it. After sufficient gripping is achieved, the bar 135 rotates with the gear 210.
[0037] Figures 5 and 6 show the rotation of the rod by the gears in progress. In Figure 5, the clamping finger 120 is automatically rotated by the closing spring 115. The closing spring 115 is released. In Figure 6, the operating lever is about to contact the release lever.
[0038] Figure 7 shows the situation after further rotation. The operating lever 110 is in contact with the pushed-out release lever 105 because the resistance force of the weak spring 105' of the release lever 105 is weaker than that of the strong spring 105'' of the release lever 105.
[0039] Figure 8 shows how rotation continues until a predetermined torque is reached, such as a pre-programmed torque within the fixture. The set torque of the fitting is reached when the screwed fitting is tightened. This can be determined by the input torque of the battery-operated screwdriver used to rotate the slotted gear 210. After the fitting torque is reached, the slotted gear 210 must be removed from the rod. To do this, the clamping fingers 120 must be retracted below the slotted gear 210. A housing (not shown) may be provided which also has slots and gear 210, so the two slots must be aligned.
[0040] The procedure for releasing gear 210 will be explained with reference to Figures 9 to 13.
[0041] Figure 9 shows the slotted gear beginning to rotate counterclockwise. In this way, the clamping fingers 120 relieve the pressure on the rod 135, allowing rotation without unscrewing the screwed-in fitting. The closing spring 115 maintains a predetermined amount of pressure on the clamping fingers 120. The operating lever 110 is not engaged with the release lever.
[0042] Figure 10 shows the situation in which the operating lever 110 engages with the release lever 105 as rotation continues. The release lever 105 is held in place in this direction by a strong spring 105" and is therefore not obstructed or disengaged.
[0043] Figure 11 shows the situation where the operating lever 110 is engaged with the release lever 105 as counterclockwise rotation continues. The rotation transmission plate 130 begins to rotate relative to the slotted gear 210, first pulling back the clamping finger 120' covering the slot, and then the other clamping finger 120. The rotation compresses the closing spring.
[0044] Figure 12 shows the situation when the slot 200 of the gear 210 is aligned with the slot in the housing (not shown) and all clamp fingers 120 are fully retracted. At this stage, the transmission plate 130 is locked against the slotted gear 210. If the slotted gear accidentally rotates further counterclockwise, it may cause damage because the actuating lever 110 cannot pass the release lever 105. Damage is prevented by the release lever 105 first disengaging before damage could occur. The force at which the above occurs can be carefully determined in advance, as the release lever 105 must not disengage until all clamp fingers 120 are fully retracted and the closing spring 115 is compressed. However, the release lever 105 must disengage before damage occurs.
[0045] Figure 13 shows the slotted gear 210 in a resting state. The rod 135 can be pulled out from the gear slot 200, or the instrument can pull the rod 135 away during use. Figure 13 is similar to Figure 2, which shows the start of the instrument use process.
[0046] As shown in Figure 14, for the clamping finger 120 to grip the bar, it is necessary that the clamping finger 120 does not slip on the bar 135 or the connector barrel. Slipping can be prevented at least partially by having serrated teeth on the clamping finger 120 and applying some preload via a transmission plate and a closing spring. However, in some cases, the spring force 1405 alone may not be sufficient to transmit the torque required to tighten the fitting or rotate the bar 135. The shape of the clamping finger may be designed such that the clockwise rotation of the slotted gear 210 increases the frictional force 1410 perpendicular to the surface of the bar 135 in contact with the bar 135 and the clamping finger 120. This perpendicular force 1410 causes the clamping finger 120 to grip the bar. The geometric shape of the clamping finger 120 may be selected such that the tangential gripping force 1415 that rotates the bar is always greater than the required torque. Alternatively, or additionally, the clamping finger 120 may have a bar contact shape that includes a plane defined perpendicular to the direction of motion of the clamping finger 120, thereby allowing the clamping finger 120 to contact a relatively large surface area of the bar 135. One or more of the forces applied to the reaction point may be measured by one or more strain gauges, thereby allowing the torque applied to the bar 135 to be determined and controlled.
[0047] Figure 15 shows the range of rod sizes 135 that the apparatus in this embodiment can achieve. Figure 15A shows the apparatus for gripping a rod 135' of a smaller diameter. Figure 15B shows the apparatus for gripping a rod 135'' of a larger diameter. The clamping fingers 120 are positioned to extend only from below the transmission plate 130 until the rod 135 is fully gripped. In this embodiment, the rod 135' of a smaller diameter is 25 mm in diameter, and the rod 135'' of a larger diameter is 46 mm in diameter. It should be noted that other diameters of rod 135 may be used with this apparatus, and both larger and smaller diameters than those in this embodiment may be provided.
[0048] Figure 16 shows the appearance of an exemplary housing 1600 used to cover one or more mechanical parts of a fixture. A gearbox 1610 may be provided on the first side, and a slotted gear 120 may be provided on the other side. An release lever system 105 for opening the clamping fingers 120 may be located between the gearbox 1610 and the slotted gear 120. A handle 1605 and a hanging bracket 1615 may be provided on the housing 1600 to assist in the use position of the fixture above the bar 135.
[0049] Figure 17 shows a lower view of a similar housing 1600. An additional handle 1705 is shown, which may be used to assist in the use position of the device above the rod 135.
[0050] Figure 18 shows a top view with the upper housing 1600 removed. In this embodiment, the gearbox 1610 is located on the right side, and a square socket 1805 is connected to the battery-powered drill. The gearbox 1610 has an output to a large overdrive (OD) gear, which transmits power to a slotted gear 210 via two idler gears. The overdrive gear is a type of gear with a gear ratio higher than 1:1, so that the output shaft of the gearbox 1610 rotates faster than the input shaft connected to the socket 1805. This improves the efficiency of power transmission and reduces wear on the tool. As the slotted gear 210 rotates, the gap 200 in the gear teeth passes through one of the idler gears 1810. The drive is maintained by the other idler gear 1810. In this way, a full 360° rotation can be performed without losing power.
[0051] Figure 19 shows three diagrams of the device, each showing a slotted gear 210 subjected to a different amount of rotation. From this diagram, we can see how the clamping fingers 120 extended when rotation occurred.
[0052] Figure 20 is similar to Figure 19, but the top of the slotted gear 210 has been removed to show the internal mechanism in more detail. This more clearly shows the mechanism for extending the clamping finger 120.
[0053] Any range or device value given herein can be extended or modified without loss of the desired effect, as will be obvious to those skilled in the art.
[0054] It will be understood that the above-mentioned benefits and advantages may relate to one embodiment or to several embodiments. The embodiments are not limited to embodiments that solve any of the above-mentioned problems or embodiments that have any of the above-mentioned benefits and advantages.
[0055] Any reference to an item “a certain” refers to one or more such items. The term “comprising” in this specification means including an identified method block or element, but such blocks or elements do not constitute an exclusive list, and a method or apparatus may include additional blocks or elements.
[0056] The steps of the methods described herein may be performed in any preferred order as appropriate, or simultaneously. Additionally, individual blocks may be removed from any of the methods without departing from the spirit and scope of the subject matter described herein. Any aspect of the above-described embodiments may be combined with any aspect of the other embodiments described herein to form further embodiments without loss of the desired effect.
[0057] The above description of preferred embodiments is given only as an example, and it will be understood that various modifications can be made by those skilled in the art. Although various embodiments have been described above with some degree of specificity or by reference to one or more individual embodiments, those skilled in the art will be able to make numerous changes to the disclosed embodiments without departing from the spirit or scope of the invention. [Explanation of symbols]
[0058] 100 joint module 105 Release Lever 105' Weak spring 105" Strong spring 110 Operating lever 115 Closure spring 120 Clamp Fingers 120' First clamp finger 125 Finger Lever 130 Rotational transmission plate 135 Bar material Rods with a diameter smaller than 135' Bar stock with a diameter greater than 135 inches 200 gear slots 210 slotted gear 305 pins 310 slots 1405 Spring force 1410 Friction force 1415 Tangential gripping force 1600 Housing 1605 Handle 1610 Gearbox 1615 Hanging hardware 1705 Handle 1805 Square socket 1810 Idragia
Claims
1. An electric tool for tightening threaded connectors, A housing with a slot-shaped opening, A slotted gear mechanism comprising a slotted gear and multiple rotating gripper cams, A transmission plate rotatably coupled to the slotted gear, wherein the transmission plate is linked to the gripper cam via the slotted gear mechanism such that the gripper cam rotates when the transmission plate rotates, A biasing means configured to bias the transmission plate so that the gripper cam rotates toward the circumference of the housing, A linkage, which is mechanically in contact with both the slotted gear and the transmission plate and includes a biased ratchet, The linkage is provided with, When the slotted gear rotates in the first direction, the linkage engages with the ratchet, thereby causing the transmission plate to rotate and compress the biasing means, which in turn rotates the gripper cam, thereby loosening the gripper cam's grip on the rod passing through the slotted housing during use. An apparatus configured such that when the slotted gear rotates in a second direction, the transmission plate rotates, causing the gripper cam to rotate, thereby tightening the gripper cam's grip on a rod passing through the slotted housing during use.
2. The device according to claim 1, wherein the biased ratchet is a spring-loaded ratchet.
3. The device according to claim 2, wherein the spring-loaded ratchet comprises a weak spring in a first direction and a strong spring in a second direction.
4. The apparatus according to claim 3, wherein the strong spring has a spring constant set to allow the ratchet to deflect at a predetermined stress level within the slotted gear mechanism.
5. The apparatus according to any one of claims 1 to 4, wherein the transmission plate is provided with one or more slot-shaped holes.
6. The apparatus according to claim 5, wherein the one or more slot-shaped holes control the point at which one or more of the gripper cams rotate when the transmission plate rotates.
7. The apparatus according to any one of claims 1 to 6, wherein one or more of the gripper cams have either a rod-contact outer shape and / or serrated teeth.
8. The apparatus according to claim 7, wherein the sawtooth-shaped teeth are oriented to bite into the surface of the rod material under the rotation of the slotted gear in the second direction during use, and to perform a grinding operation as they travel above the surface of the rod material under the rotation of the slotted gear in the first direction.
9. The device according to any one of claims 1 to 8, wherein the slotted gear is rotatably held in a predetermined position by an open sliding bearing disposed between the slotted gear and the housing.
10. The device according to any one of claims 1 to 9, wherein the slotted gear is driven by one or more idler gears.
11. The apparatus according to claim 10, wherein the one or more idler gears are driven by a single drive gear.
12. The apparatus according to claim 10 or 11, wherein the spacing of the idler gears is such that the slotted gear remains driven at all times.
13. The apparatus according to claim 11, wherein the single drive gear is driven by a motor assembly.
14. The device according to claim 13, wherein the motor assembly comprises a gearbox.
15. The apparatus according to claim 13 or 14, wherein the motor is separated from the apparatus and connected to a gearbox or directly to the single drive gear via a socket.
16. The apparatus according to any one of claims 1 to 15, wherein the housing is operable to bring two or more rod members into contact with each other and substantially seal them.
17. The apparatus according to any one of claims 1 to 16, further comprising one or more strain gauges.
18. The apparatus according to any one of claims 1 to 17, wherein the ratchet is aligned with the transmission plate so that, under rotation in a first direction, the slotted opening of the housing and the slotted opening of the slotted gear are aligned, and at the same time, the slotted opening is substantially away from any portion of the gripper cam.
19. A method for tightening a threaded connection using an electric device according to any one of claims 1 to 18.
20. A method for tightening threaded connectors, The step includes using an electric device, the electric device being: A housing with a slot-shaped opening, A slotted gear mechanism comprising a slotted gear and multiple rotating gripper cams, A transmission plate rotatably coupled to the slotted gear, wherein the transmission plate is linked to the gripper cam via the slotted gear mechanism such that the gripper cam rotates when the transmission plate rotates, A biasing means configured to bias the transmission plate so that the gripper cam rotates toward the circumference of the housing, A linkage and a biased ratchet are mechanically in contact with both the slotted gear and the transmission plate. Equipped with, The aforementioned method, The steps include: rotating the slotted gear in a first direction to engage the linkage on the ratchet, thereby rotating the transmission plate to compress the biasing means and rotating the gripper cam, thereby loosening the gripper cam's grip on the rod passing through the slotted housing during use; The steps include: rotating the slotted gear in a second direction to rotate the transmission plate, rotating the gripper cam, thereby tightening the gripper cam's grip on the rod passing through the slotted housing during use; Methods that include...