A telescopic gate puller device and a telescopic operation method thereof
By using a square tie rod structure and pin design, the operation of the tie rod of the high-head submersible steel gate is simplified, solving the problems of cumbersome operation and large space occupation in the existing technology, and realizing rapid extension and retraction and efficient gate control.
Patent Information
- Application Number
- CN202211260967.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-10-14
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2042-10-14
AI Technical Summary
The existing high-head submersible steel gate has a cumbersome rod structure that requires multiple disassembly and reassembly, occupies a lot of space, and the hook needs to be hooked and unhooked multiple times, making it inconvenient to operate.
The design employs a square tie rod structure, with through holes and pins between the outer and inner square tie rods, combined with a movable support beam, to achieve easy locking and unlocking of the inner and outer tie rods, simplifying the operation process.
It enables rapid extension and retraction of the gate, reduces the need for multiple hooking and unhooking actions, improves operational efficiency, reduces space occupation, and has a simple and easy-to-implement structure.
Smart Images
Figure CN115613523B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a retractable gate lever device and its retractable operation method. Background Technology
[0002] High-head submersible steel gates often use tie rods to increase the opening and closing stroke. Existing gate technologies mostly use tie rod combination structures, with multiple tie rod sections connected by hinge shafts. When it is necessary to lift the gate out of the orifice, the hoist lifts the tie rods to a fixed position, the lower tie rod section is locked with a crossbeam, the connecting shaft between the tie rods is removed, and then the upper tie rod section is disassembled. Subsequently, each tie rod section is removed in turn until the gate is completely lifted. This type of tie rod is relatively cumbersome to use, requiring the disassembly of the tie rods. The lifting and lowering of the entire gate takes a lot of time, and additional space is required to place the tie rods, occupying a large space.
[0003] Chinese Patent Publication No. CN215629794U discloses a gate telescopic rod. The technical solution adopted is that the outermost rod is used to connect with the gate. There is no locking and unlocking structure between the inner and outer rods. This means that after each section of the rod is lifted, the crane hook is connected to the tension bracket of the outer rod. In other words, the hook needs to be hooked and unhooked multiple times during use, which is quite troublesome. Summary of the Invention
[0004] The present invention overcomes the shortcomings of the above-mentioned technologies and provides a telescopic gate lever device and its telescopic operation method.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A retractable gate lever device includes a base 1 and a retractable lever assembly. The base 1 has a vertical through groove 11 for the retractable lever assembly to extend vertically. The retractable lever assembly includes multiple nested square levers, including an outermost square outer lever 21, an innermost square inner lever 23, and one or more square middle levers 22 located between the outer and inner square levers 21 and 23. The upper end of the outer square lever 21 is provided with an upper... Connector 211, the lower end of the square inner tie rod 23 is provided with a lower connector 231, and each tie rod has a left side wall 31, a front side wall 32, a right side wall 33, and a rear side wall 34 arranged sequentially on its outer periphery. The upper end of the left side wall 31 and the right side wall 33 of each tie rod is provided with an outwardly protruding upper load-bearing beam 41, and the lower end of each is provided with an outwardly protruding lower load-bearing beam 42. The lower load-bearing beam 42 of the square outer tie rod 21 and the lower load-bearing beam 42 of the square middle tie rod 22 are connected to a device for connecting the inner layer. The upper and lower load-bearing beams of the rod are blocked and limited by limiting blocks 5 to prevent the inner tie rod from detaching upwards and downwards relative to the outer tie rod. Each tie rod has through holes 30 on its front side wall 32 and rear side wall 34. When the inner tie rod is retracted to its final position relative to the outer tie rod, the through holes 30 on the front side wall 32 and rear side wall 34 of the inner and outer tie rods are aligned. A pin 6 capable of inward and outward movement is movably connected to the through hole 30 of the square outer tie rod 21. The pin 6 moves inwards... The pin 6 is inserted into the through hole 30 of the inner tie rod. After being inserted into the through hole 30, the pin 6 can prevent the inner tie rod from moving up and down relative to the outer tie rod. The pin 6 moves outward to disengage from the through hole 30 of the inner tie rod. After disengaging from the through hole, the pin 6 does not prevent the inner tie rod from moving up and down relative to the outer tie rod. The seat 1 corresponding to the left wall 31 and the seat 1 corresponding to the right wall 33 are respectively movably connected to the load-bearing beam 7, which can move laterally to support / avoid the tie rod.
[0007] Preferably, the seat body 1 on the left and right sides of the vertical through groove 11 is provided with a transverse guide groove 12 for the corresponding movable support beam 7 to pass through, and the movable support beam 7 on the side away from the vertical through groove 11 is provided with a first handle part 71.
[0008] Preferably, the lower load-bearing beam 42 is detachably fixed to the limiting block 5 by means of a bolt and nut assembly 43.
[0009] Preferably, the through holes 30 are all elliptical in shape with their major axis extending vertically. The outer end of the pin 6 is provided with a second handle part 61, and the inner end is provided with a limiting part 62 to prevent the pin 6 from arbitrarily entering or exiting the through hole 30. Rotating the pin 6 can change the swing direction of the limiting part 62 so as to control whether the limiting part 62 can enter or exit the through hole 30.
[0010] Preferably, the outer periphery of the pin 6 has a plurality of radially extending and sequentially distributed positioning insertion holes 63 for the insertion of the insert 8 in a detachable manner.
[0011] Preferably, the upper connector 211 and the lower connector 231 are each provided with a plurality of connection holes.
[0012] Preferably, the device further includes a lifting and lowering mechanism connected to the upper connector 211.
[0013] This case also protects a method for operating a telescopic gate lever device, which includes the following steps:
[0014] In the step of extending the inner tie rod, the pin 6 is moved so that it disengages from the through hole 30 of the N inner tie rods that are to extend relative to the outer tie rod, so as not to obstruct the up and down movement of the N inner tie rods relative to their outer tie rods. Then, the square outer tie rod 21 is lifted upward by the lifting and lowering mechanism, so that the N inner tie rods that are to extend downward relative to the outer tie rod are exposed and their upper load-bearing beam 41 contacts the limiting block 5 of their outer tie rods. Then, the movable support beam 7 is moved outward so that it does not obstruct the downward movement of the N inner tie rods. The lifting and lowering mechanism lowers the square outer tie rod 21 so that the N inner tie rods also move downward. The position of the movable support beam 7 is adjusted so that it can support the load-bearing beam of the outer tie rod, where N is 1 or a natural number greater than 1.
[0015] The inner tie rod retraction step involves the hoisting and lowering mechanism lifting the square outer tie rod 21 upwards, causing the M inner tie rods that are to be retracted relative to the outer tie rod to move upwards, and ensuring that the lower load-bearing beam 42 of the innermost of the M inner tie rods reaches at least the corresponding height of the movable support beam 7. The movable support beam 7 is then moved to support the lower load-bearing beam 42. The hoisting and lowering mechanism then lowers the square outer tie rod 21 until the through holes 30 of the M inner tie rods reach the position of the pin 6. The pin 6 is then moved to pass through the through holes 30, where M is a natural number of 1 or greater than 1.
[0016] Preferably, the value of N when performing the step of extending the inner layer tie rod in the current step is the same as or different from the value of N when performing the step of extending the inner layer tie rod in the next step.
[0017] Preferably, the value of N when performing the inner layer tie rod retraction step is the same as or different from the value of N when performing the next inner layer tie rod retraction step.
[0018] Compared with the prior art, the beneficial effects of the present invention are:
[0019] 1. The telescopic gate lever device of this invention has a simple and easy-to-implement structure. The square lever design allows for the installation of the upper and lower load-bearing beams on two opposite sidewalls of the four sidewalls, while the through holes are located on the remaining two opposite sidewalls. This ensures that during operation, the action of supporting the load-bearing beams of the lever via the movable support beam on the base and the action of inserting and withdrawing the pin through the through holes are not on the same sidewall, minimizing mutual obstruction and facilitating operation. The lower load-bearing beams of both the outer and middle square levers are connected to limiting blocks to restrict and limit the upper and lower load-bearing beams of the inner lever, preventing the inner lever from detaching upwards relative to the outer lever. The inner tie rod retracts downwards when its upward movement relative to the outer tie rod is obstructed, and extends downwards when its downward movement relative to the outer tie rod is obstructed, thus serving as a limiting and positioning mechanism with good practicality. Furthermore, compared to the existing technology CN215629794U, this invention uses the through hole and pin to lock and unlock the inner and outer tie rods. In specific lifting and lowering operations, simply lifting and lowering the square outer tie rod will cause the inner tie rods locked to it to move up and down together. Therefore, in practical use, the lifting and lowering mechanism only needs to connect to the upper connector of the square outer tie rod, without requiring multiple hooking and unhooking actions, resulting in good practicality.
[0020] 2. The lower load-bearing beam is detachably fixed to the limiting block by a bolt and nut assembly. This facilitates the nesting of the inner and outer tie rods when the limiting block is not connected, and also facilitates the disassembly and replacement of the tie rods during subsequent maintenance.
[0021] 3. The outer periphery of the pin has a plurality of radially extending and sequentially distributed positioning insertion holes for detachable insertion of the insert strip. In specific implementation, when the pin is to be passed inward through the through hole of an inner pull rod, the insert strip is first taken out from the current positioning insertion hole and inserted into the previous positioning insertion hole on the outer side, and then the pin is moved inward. When the insert strip abuts against the outer wall of the pull rod, it indicates that it has been moved into place, which is convenient to implement.
[0022] 4. The telescopic operation method of the telescopic gate lever device in this case includes the steps of extending the inner lever and retracting the inner lever, which facilitates the control of the telescopic operation of the lever device. In the step of extending the inner lever, the latch is first operated to unlock, then the hoisting and lowering mechanism first lifts the square outer lever and operates the movable support beam to avoid it, and finally the hoisting and lowering mechanism lowers the square outer lever and adjusts the movable support beam for support. This helps to avoid the situation where the inner lever drops sharply under gravity directly after unlocking and after support and avoidance, which is practical. In the step of retracting the inner lever, the method of first lifting, then supporting and limiting, and finally lowering and locking is adopted. The whole process is quick to operate and has good practicality. Attached Figure Description
[0023] Figure 1 This is one of the structural diagrams of the telescopic gate lever device in this case.
[0024] Figure 2 This is one of the structural diagrams of the telescopic gate lever device in this case.
[0025] Figure 3 This is an exploded view of the retractable gate lever device in this case.
[0026] Figure 4 This is a structural diagram of the base in this case.
[0027] Figure 5 This is a structural diagram of the latch in this case. Detailed Implementation
[0028] The following examples further illustrate the features and other related characteristics of the present invention in detail, to facilitate understanding by those skilled in the art:
[0029] like Figures 1 to 5As shown, a telescopic gate lever device includes a base 1 and a telescopic lever assembly. The base 1 has a vertical through groove 11 for the telescopic lever assembly to extend vertically. The telescopic lever assembly includes multiple nested square levers, including an outermost square outer lever 21, an innermost square inner lever 23, and one or more square middle levers 22 located between the outer and inner square levers 21. The upper end of the outer square lever 21 is provided with an upper... Connector 211, the lower end of the square inner tie rod 23 is provided with a lower connector 231, and each tie rod has a left side wall 31, a front side wall 32, a right side wall 33, and a rear side wall 34 arranged sequentially on its outer periphery. The upper end of the left side wall 31 and the right side wall 33 of each tie rod is provided with an outwardly protruding upper load-bearing beam 41, and the lower end of each is provided with an outwardly protruding lower load-bearing beam 42. The lower load-bearing beam 42 of the square outer tie rod 21 and the lower load-bearing beam 42 of the square middle tie rod 22 are respectively connected to a connector for... The load-bearing beam of the inner tie rod is blocked by a limiting block 5 to prevent the inner tie rod from detaching upwards or downwards relative to the outer tie rod. Each tie rod has through holes 30 on its front side wall 32 and rear side wall 34. When the inner tie rod is retracted to its final position relative to the outer tie rod, the through holes 30 on the front side wall 32 and rear side wall 34 of the inner and outer tie rods are aligned. A movable pin 6 is connected to the through hole 30 of the square outer tie rod 21, allowing it to move inwards and outwards. The pin 6 moves inwards... The pin 6 is inserted into the through hole 30 of the inner tie rod. After being inserted into the through hole 30, the pin 6 can prevent the inner tie rod from moving up and down relative to the outer tie rod. The pin 6 moves outward to disengage from the through hole 30 of the inner tie rod. After disengaging from the through hole, the pin 6 does not prevent the inner tie rod from moving up and down relative to the outer tie rod. The seat 1 corresponding to the left wall 31 and the seat 1 corresponding to the right wall 33 are respectively movably connected to the load-bearing beam 7, which can move laterally to support / avoid the tie rod.
[0030] As described above, in a specific implementation, when the movable support beam 7 supports the lower load-bearing beam 42, it can support the limiting block 5 connected to the lower load-bearing beam 42, such as when the limiting block 5 connected to the lower load-bearing beam 42 blocks the lower end face of the lower load-bearing beam 42.
[0031] As described above, the telescopic gate lever device of this invention has a simple and easy-to-implement structure. The square lever design allows for the installation of the upper load-bearing beam 41 and lower load-bearing beam 42 on two opposite sidewalls of the four sidewalls of the square lever, while the through holes 30 are provided on the remaining two opposite sidewalls. This ensures that during actual use, the action of supporting the load-bearing beams of the lever via the movable support beam 7 on the base 1 and the action of inserting and exiting the lever through the through holes 30 via the pin 6 are not on the same sidewall, thus minimizing mutual obstruction and facilitating operation. The lower load-bearing beam 42 of both the outer square lever 21 and the middle square lever 22 are connected to limiting blocks 5, which are used to block and limit the upper and lower load-bearing beams of the inner lever to prevent the inner lever from being too close to the outer lever. The pull rods can be disengaged upwards and downwards, meaning that when the inner pull rod is obstructed from moving upwards relative to the outer pull rod, it retracts into place; and when the inner pull rod is obstructed from moving downwards relative to the outer pull rod, it extends into place, serving as a limiting and positioning mechanism with good practicality. Furthermore, compared to the existing technology CN215629794U, this invention uses the through hole 30 and the pin 6 to lock and unlock the inner and outer pull rods. In specific lifting and lowering operations, simply lifting and lowering the square outer pull rod 21 will cause the inner pull rods locked to it to move up and down together. Thus, in practical use, the lifting and lowering mechanism only needs to connect to the upper connector 211 of the square outer pull rod 21, without requiring multiple hooking and unhooking actions, resulting in good practicality.
[0032] like Figure 4 As shown, in a specific implementation, the seat body 1 on the left and right sides of the vertical through groove 11 is provided with a transverse guide groove 12 for the corresponding movable support beam 7 to pass through, which facilitates the guiding movement. The movable support beam 7 on the side away from the vertical through groove 11 is provided with a first handle part 71, which facilitates the manual operation to move the movable support beam 7.
[0033] like Figure 1 As shown, the lower load-bearing beam 42 is detachably fixed to the limiting block 5 by the bolt and nut assembly 43. This facilitates the nesting of the inner and outer tie rods when the limiting block 5 is not connected, and also facilitates the disassembly and replacement of the tie rods during subsequent maintenance.
[0034] like Figure 1 , Figure 2 , Figure 5 As shown, in specific implementation, the through holes 30 are all elliptical in shape with their major axes extending vertically. The outer end of the pin 6 is provided with a second handle part 61, and the inner end is provided with a limiting part 62 to prevent the pin 6 from arbitrarily entering or exiting the through hole 30. Rotating the pin 6 can change the swing direction of the limiting part 62 so as to control whether the limiting part 62 can enter or exit the through hole 30, which is convenient for preventing dislodgement and limiting.
[0035] like Figure 5 As shown, the outer periphery of the pin 6 has a plurality of radially extending and sequentially distributed positioning insertion holes 63 for the detachable insertion of the insert strip 8. In specific implementation, when the pin 6 is to be passed inward through the through hole 30 of an inner pull rod, the insert strip 8 is first taken out from the current positioning insertion hole 63 and inserted into the previous positioning insertion hole 63 on the outer side, and then the pin 6 is moved inward. When the insert strip 8 abuts against the outer wall of the pull rod, it indicates that it has been moved into place, which is convenient to implement.
[0036] As described above, in specific implementation, the upper connector 211 and the lower connector 231 are each provided with a plurality of connection holes.
[0037] As described above, in a specific implementation, it also includes a lifting and lowering mechanism connected to the upper connector 211, which is not shown in the figure.
[0038] As stated above, this case also discloses a method for operating the telescopic gate lever device, which includes the following steps:
[0039] In the step of extending the inner tie rod, the pin 6 is moved so that it disengages from the through hole 30 of the N inner tie rods that are to extend relative to the outer tie rod, so as not to obstruct the up and down movement of the N inner tie rods relative to their outer tie rods. Then, the square outer tie rod 21 is lifted upward by the lifting and lowering mechanism, so that the N inner tie rods that are to extend downward relative to the outer tie rod are exposed and their upper load-bearing beam 41 contacts the limiting block 5 of their outer tie rods. Then, the movable support beam 7 is moved outward so that it does not obstruct the downward movement of the N inner tie rods. The lifting and lowering mechanism lowers the square outer tie rod 21 so that the N inner tie rods also move downward. The position of the movable support beam 7 is adjusted so that it can support the load-bearing beam of the outer tie rod, where N is 1 or a natural number greater than 1.
[0040] The inner tie rod retraction step involves the hoisting and lowering mechanism lifting the square outer tie rod 21 upwards, causing the M inner tie rods that are to be retracted relative to the outer tie rod to move upwards, and ensuring that the lower load-bearing beam 42 of the innermost of the M inner tie rods reaches at least the corresponding height of the movable support beam 7. The movable support beam 7 is then moved to support the lower load-bearing beam 42. The hoisting and lowering mechanism then lowers the square outer tie rod 21 until the through holes 30 of the M inner tie rods reach the position of the pin 6. The pin 6 is then moved to pass through the through holes 30, where M is a natural number of 1 or greater than 1.
[0041] As described above, the telescopic operation method of the telescopic gate lever device in this case includes the steps of extending the inner lever and retracting the inner lever, which facilitates the control of the telescopic operation of the lever device. In the step of extending the inner lever, the latch 6 is first operated to unlock, then the hoisting and lowering mechanism first lifts the square outer lever 21 upward and operates the movable support beam 7 to avoid it, and finally the hoisting and lowering mechanism lowers the square outer lever 21 and adjusts the movable support beam 7 for support. This helps to avoid the situation where the inner lever drops sharply under gravity directly after unlocking and after support and avoidance, which is practical. In the step of retracting the inner lever, the method of first lifting, then supporting and limiting, and finally lowering and locking is adopted. The whole process is quick to operate and practical.
[0042] As described above, in specific implementation, the value of N when performing the step of extending the inner layer tie rod in the current instance may be the same as or different from the value of N when performing the step of extending the inner layer tie rod in the next instance. The user can operate the device to extend several inner layer tie rods according to actual needs.
[0043] As described above, in specific implementation, the value of N when performing the current inner layer tie rod retraction step may be the same as or different from the value of N when performing the next inner layer tie rod retraction step. The user can operate the device to retract several inner layer tie rods according to actual needs.
[0044] As stated above, this case protects a retractable gate lever device and its retractable operation method. All technical solutions that are the same as or similar to this case should be considered to fall within the protection scope of this case.
Claims
1. A telescopic gate lever device, characterized in that... The device includes a base (1) and a telescopic rod assembly. The base (1) has a vertical through groove (11) for the telescopic rod assembly to extend vertically. The telescopic rod assembly includes multiple nested square rods, including an outer square outer rod (21), an inner square inner rod (23), and one or more square middle rods (22) between the outer square rod (21) and the inner square rod (23). The upper end of the outer square rod (21) is provided with an upper connector (211), and the lower end of the inner square rod (23) is provided with a lower connector (231). Each rod has a left side wall (31), a front side wall (32), and a right side wall (33) on its outer periphery. The rear side wall (34), the upper end of the left side wall (31) and the right side wall (33) of each tie rod are respectively provided with an upper load-bearing beam (41) protruding outward, and the lower end of each tie rod is respectively provided with a lower load-bearing beam (42) protruding outward. The lower load-bearing beam (42) of the square outer tie rod (21) and the lower load-bearing beam (42) of the square middle tie rod (22) are connected with a limiting block (5) for blocking and limiting the upper and lower load-bearing beams of the inner tie rod to prevent the inner tie rod from detaching upward and downward relative to the outer tie rod. The front side wall (32) and the rear side wall (34) of each tie rod are provided with through holes (30). When the inner tie rod is retracted into place relative to the outer tie rod, the positions of the through holes (30) on the front side wall (32) of the inner and outer tie rods are opposite. The through holes (30) on the rear side wall (34) are positioned opposite each other. A pin (6) that can move inward and outward is movably connected to the through hole (30) of the square outer pull rod (21). The pin (6) moves inward to insert into the through hole (30) of the inner pull rod. After being inserted into the through hole (30), the pin (6) can prevent the inner pull rod from moving up and down relative to the outer pull rod. The pin (6) moves outward to disengage from the through hole (30) of the inner pull rod. After being disengaged from the through hole, the pin (6) does not prevent the inner pull rod from moving up and down relative to the outer pull rod. The seat (1) corresponding to the left side wall (31) and the seat (1) corresponding to the right side wall (33) are respectively movably connected to a support / avoidance device that can move laterally. The movable support beam (7) of the load-bearing beam of the tie rod has transverse guide grooves (12) on the left and right sides of the seat (1) of the vertical through groove (11) for the movable support beam (7) on the corresponding side to pass through. The movable support beam (7) on the side away from the vertical through groove (11) has a first handle (71). The through holes (30) are all elliptical in shape with the major axis extending vertically. The outer end of the pin (6) has a second handle (61) and the inner end has a limiting part (62) to prevent the pin (6) from randomly entering or exiting the through hole (30). Rotating the pin (6) can change the swing direction of the limiting part (62) so as to control whether the limiting part (62) can enter or exit the through hole (30).The pin (6) has radially extending and sequentially distributed positioning insertion holes (63) on its outer periphery for the detachable insertion of the insert strip (8).
2. The telescopic gate lever device according to claim 1, characterized in that... The lower load-bearing beam (42) is detachably fixed to the limiting block (5) by means of a bolt and nut assembly (43).
3. The telescopic gate lever device according to claim 1, characterized in that... The upper connector (211) and the lower connector (231) are each provided with a number of connection holes.
4. A telescopic gate lever device according to any one of claims 1-3, characterized in that... The device also includes a lifting and lowering mechanism connected to the upper connector (211).
5. A method for telescopic operation of the telescopic gate lever device according to claim 4, characterized in that... The steps include the following: In the step of extending the inner tie rod, the pin (6) is moved so that it disengages from the through hole (30) of the N inner tie rods that are to extend relative to the outer tie rod, so as not to hinder the N inner tie rods from moving up and down relative to their outer tie rods. Then, the square outer tie rod (21) is lifted upward by the lifting and lowering mechanism so that the N inner tie rods that are to extend downward relative to the outer tie rod are exposed and their upper load-bearing beam (41) contacts the limiting block (5) of their outer tie rod. Then, the movable support beam (7) is moved outward so that it does not hinder the N inner tie rods from moving downward. The lifting and lowering mechanism lowers the square outer tie rod (21) so that the N inner tie rods also move downward. The position of the movable support beam (7) is adjusted so that it can support the load-bearing beam of the outer tie rod, where N is 1 or a natural number greater than 1. In the retraction step of the inner tie rod, the hoisting and lowering mechanism lifts the square outer tie rod (21) upward, causing the M inner tie rods that are to be retracted relative to the outer tie rod to move upward, and making the lower load-bearing beam (42) of the innermost tie rod among the M inner tie rods reach at least the corresponding height of the movable support beam (7). The movable support beam (7) is moved to support the lower load-bearing beam (42). Then the hoisting and lowering mechanism lowers the square outer tie rod (21) until the through hole (30) of the M inner tie rods reaches the position of the pin (6). The pin (6) is moved to pass through the through hole (30), where M is 1 or a natural number greater than 1.
6. The telescopic operation method of the telescopic gate lever device according to claim 5, characterized in that... The value of N when performing the step of extending the inner tie rod in the current instance may be the same as or different from the value of N when performing the step of extending the inner tie rod in the next instance.
7. The telescopic operation method of the telescopic gate lever device according to claim 5, characterized in that... The value of N when performing the inner layer tie rod retraction step is the same as or different from the value of N when performing the next inner layer tie rod retraction step.